[2/2] drm: bridge: Add SN65DSI84 DSI to LVDS bridge
diff mbox series

Message ID 20210120112158.62109-2-jagan@amarulasolutions.com
State New
Headers show
Series
  • [1/2] dt-bindings: display: bridge: Add documentation for SN65DSI84
Related show

Commit Message

Jagan Teki Jan. 20, 2021, 11:21 a.m. UTC 
SN65DSI84 is a Single Channel DSI to Dual-link LVDS bridge from
Texas Instruments.

SN65DSI83, SN65DSI85 are variants of the same family of bridge
controllers.

Right now the bridge driver is supporting a single link, dual-link
support requires to initiate I2C Channel B registers.

Tested with STM32MP1 MIPI DSI host design configuration.

Signed-off-by: Matteo Lisi <matteo.lisi@engicam.com>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
 MAINTAINERS                           |   6 +
 drivers/gpu/drm/bridge/Kconfig        |  19 +
 drivers/gpu/drm/bridge/Makefile       |   1 +
 drivers/gpu/drm/bridge/ti-sn65dsi84.c | 488 ++++++++++++++++++++++++++
 4 files changed, 514 insertions(+)
 create mode 100644 drivers/gpu/drm/bridge/ti-sn65dsi84.c

Comments

Michael Trimarchi Jan. 20, 2021, 11:25 a.m. UTC | #1 
Hi Jagan

On Wed, Jan 20, 2021 at 12:22 PM Jagan Teki <jagan@amarulasolutions.com> wrote:
>
> SN65DSI84 is a Single Channel DSI to Dual-link LVDS bridge from
> Texas Instruments.
>
> SN65DSI83, SN65DSI85 are variants of the same family of bridge
> controllers.
>
> Right now the bridge driver is supporting a single link, dual-link
> support requires to initiate I2C Channel B registers.
>
> Tested with STM32MP1 MIPI DSI host design configuration.
>
> Signed-off-by: Matteo Lisi <matteo.lisi@engicam.com>
> Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> ---
>  MAINTAINERS                           |   6 +
>  drivers/gpu/drm/bridge/Kconfig        |  19 +
>  drivers/gpu/drm/bridge/Makefile       |   1 +
>  drivers/gpu/drm/bridge/ti-sn65dsi84.c | 488 ++++++++++++++++++++++++++
>  4 files changed, 514 insertions(+)
>  create mode 100644 drivers/gpu/drm/bridge/ti-sn65dsi84.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 12dd1fff2a39..44750ff7640c 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -5984,6 +5984,12 @@ S:       Maintained
>  F:     Documentation/devicetree/bindings/display/ti/
>  F:     drivers/gpu/drm/omapdrm/
>
> +DRM DRIVERS FOR TI SN65DSI84 DSI TO LVDS BRIDGE
> +M:     Jagan Teki <jagan@amarulasolutions.com>
> +S:     Maintained
> +F:     Documentation/devicetree/bindings/display/bridge/ti,sn65dsi84.yaml
> +F:     drivers/gpu/drm/bridge/ti-sn65dsi84.c
> +
>  DRM DRIVERS FOR V3D
>  M:     Eric Anholt <eric@anholt.net>
>  S:     Supported
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index e4110d6ca7b3..6494881bffb3 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -232,6 +232,25 @@ config DRM_TI_TFP410
>         help
>           Texas Instruments TFP410 DVI/HDMI Transmitter driver
>
> +config DRM_TI_SN65DSI84
> +       tristate "TI SN65DSI84 DSI to LVDS bridge"
> +       depends on OF
> +       select DRM_KMS_HELPER
> +       select REGMAP_I2C
> +       select DRM_PANEL
> +       select DRM_MIPI_DSI
> +       help
> +         Texas Instruments SN65DSI84 Single Channel DSI to Dual-link LVDS
> +         bridge driver.
> +
> +         Bridge decodes MIPI DSI 18bpp RGB666 and 240bpp RG888 packets and
> +         converts the formatted video data stream to a FlatLink compatible
> +         LVDS output operating at pixel clocks operating from 25 MHx to
> +         154 MHz.
> +
> +         SN65DSI84 offers a Dual-Link LVDS, Single-Link LVDS interface with
> +         four data lanes per link.
> +
>  config DRM_TI_SN65DSI86
>         tristate "TI SN65DSI86 DSI to eDP bridge"
>         depends on OF
> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> index 86e7acc76f8d..3906052ef639 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -20,6 +20,7 @@ obj-$(CONFIG_DRM_TOSHIBA_TC358767) += tc358767.o
>  obj-$(CONFIG_DRM_TOSHIBA_TC358768) += tc358768.o
>  obj-$(CONFIG_DRM_TOSHIBA_TC358775) += tc358775.o
>  obj-$(CONFIG_DRM_I2C_ADV7511) += adv7511/
> +obj-$(CONFIG_DRM_TI_SN65DSI84) += ti-sn65dsi84.o
>  obj-$(CONFIG_DRM_TI_SN65DSI86) += ti-sn65dsi86.o
>  obj-$(CONFIG_DRM_TI_TFP410) += ti-tfp410.o
>  obj-$(CONFIG_DRM_TI_TPD12S015) += ti-tpd12s015.o
> diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi84.c b/drivers/gpu/drm/bridge/ti-sn65dsi84.c
> new file mode 100644
> index 000000000000..3ed1f9a7d898
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/ti-sn65dsi84.c
> @@ -0,0 +1,488 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2021 Engicam srl
> + * Copyright (C) 2021 Amarula Solutions(India)
> + * Author: Jagan Teki <jagan@amarulasolutions.com>
> + */
> +
> +#include <drm/drm_of.h>
> +#include <drm/drm_panel.h>
> +#include <drm/drm_print.h>
> +#include <drm/drm_mipi_dsi.h>
> +
> +#include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +
> +/* sn65dsi84 registers */
> +#define SN65DSI_SOFT_RESET             0x09
> +#define SN65DSI_LVDS_CLK               0x0a
> +#define SN65DSI_CLK_DIV                        0x0b
> +#define SN65DSI_CLK_PLL                        0x0d
> +#define SN65DSI_DSI_CFG                        0x10
> +#define SN65DSI_DSI_CLK_EQ             0x11
> +#define SN65DSI_DSI_CLK_RANGE          0x12
> +#define SN65DSI_LVDS_MODE              0x18
> +#define SN65DSI_CHA_LINE_LO            0x20
> +#define SN65DSI_CHA_LINE_HI            0x21
> +#define SN65DSI_CHA_VIRT_LO            0x24
> +#define SN65DSI_CHA_VIRT_HI            0x25
> +#define SN65DSI_CHA_SYNC_DELAY_LO      0x28
> +#define SN65DSI_CHA_SYNC_DELAY_HI      0x29
> +#define SN65DSI_CHA_HSYNC_WIDTH_LO     0x2c
> +#define SN65DSI_CHA_HSYNC_WIDTH_HI     0x2d
> +#define SN65DSI_CHA_VSYNC_WIDTH_LO     0x30
> +#define SN65DSI_CHA_VSYNC_WIDTH_HI     0x31
> +#define SN65DSI_CHA_HBACK_PORCH                0x34
> +#define SN65DSI_CHA_VBACK_PORCH                0x36
> +#define SN65DSI_CHA_HFRONT_PORCH       0x38
> +#define SN65DSI_CHA_VFRONT_PORCH       0x3a
> +#define SN65DSI_CHA_ERR                        0xe5
> +
> +/* sn65dsi register bits */
> +#define SN65DSI_RESET_EN               BIT(0)
> +#define SN65DSI_PLL_EN                 BIT(0)
> +#define SN65DSI_LVDS_CLK_MASK          GENMASK(3, 1)
> +#define SN65DSI_LVDS_CLK_SHIFT         1
> +#define SN65DSI_LVDS_CLK_SRC_DSI       BIT(0)
> +#define SN65DSI_CLK_DIV_MASK           GENMASK(7, 3)
> +#define SN65DSI_CLK_DIV_SHIFT          3
> +#define SN65DSI_DSI_LANE_MASK          GENMASK(4, 3)
> +#define SN65DSI_DSI_LANE_SHIFT         3
> +#define SN65DSI_LVDS_LINK_CFG          BIT(4)
> +#define SN65DSI_LVDS_CHA_24BPP         BIT(3)
> +#define SN65DSI_CHA_LOW_SYNC_DELAY     0x20
> +#define SN65DSI_CHA_HIGH_SYNC_DELAY    0x00
> +
> +struct sn65dsi {
> +       struct device                   *dev;
> +       struct drm_bridge               bridge;
> +       struct drm_bridge               *panel_bridge;
> +
> +       struct device_node              *host_node;
> +       struct mipi_dsi_device          *dsi;
> +       u8                              dsi_lanes;
> +
> +       struct regmap                   *regmap;
> +       struct gpio_desc                *enable;
> +};
> +
> +static const struct regmap_config sn65dsi_regmap_config = {
> +       .reg_bits = 8,
> +       .val_bits = 8,
> +       .max_register = SN65DSI_CHA_ERR,
> +       .name = "sn65dsi",
> +       .cache_type = REGCACHE_RBTREE,
> +};
> +
> +static inline struct sn65dsi *bridge_to_sn65dsi(struct drm_bridge *bridge)
> +{
> +       return container_of(bridge, struct sn65dsi, bridge);
> +}
> +
> +static struct drm_display_mode *bridge_to_mode(struct drm_bridge *bridge)
> +{
> +       return &bridge->encoder->crtc->state->mode;
> +}
> +
> +static void sn65dsi_setup_channels(struct sn65dsi *sn,
> +                                  struct drm_display_mode *mode)
> +{
> +       u32 hsync_len, hfront_porch, hback_porch;
> +       u32 vsync_len, vfront_porch, vback_porch;
> +
> +       hfront_porch = mode->hsync_start - mode->hdisplay;
> +       hsync_len = mode->hsync_end - mode->hsync_start;
> +       hback_porch = mode->htotal - mode->hsync_end;
> +
> +       vfront_porch = mode->vsync_start - mode->vdisplay;
> +       vsync_len = mode->vsync_end - mode->vsync_start;
> +       vback_porch = mode->vtotal - mode->vsync_end;
> +
> +       /* cha, lower 8-bits of hdisplay */
> +       regmap_write(sn->regmap, SN65DSI_CHA_LINE_LO, mode->hdisplay & 0xff);
> +
> +       msleep(10);
> +

I don't find any reason for those msleep. I don't have on my setup
with the same bridge

> +       /* cha, upper 4-bits of hdisplay */
> +       regmap_write(sn->regmap, SN65DSI_CHA_LINE_HI, (mode->hdisplay >> 8) & 0xff);
> +
> +       msleep(10);
> +
> +       /* cha, lower 8-bits of vdisplay */
> +       regmap_write(sn->regmap, SN65DSI_CHA_VIRT_LO, mode->vdisplay & 0xff);
> +
> +       msleep(10);
> +
> +       /* cha, upper 4-bits of vdisplay */
> +       regmap_write(sn->regmap, SN65DSI_CHA_VIRT_HI, (mode->vdisplay >> 8) & 0xff);
> +
> +       msleep(10);
> +
> +       /*cha, lower sync delay */
> +       regmap_write(sn->regmap, SN65DSI_CHA_SYNC_DELAY_LO, SN65DSI_CHA_LOW_SYNC_DELAY);
> +
> +       msleep(10);
> +
> +       /*cha, upper sync delay */
> +       regmap_write(sn->regmap, SN65DSI_CHA_SYNC_DELAY_HI, SN65DSI_CHA_HIGH_SYNC_DELAY);
> +
> +       msleep(10);
> +
> +       /* cha, lower 8-bits of hsync_len */
> +       regmap_write(sn->regmap, SN65DSI_CHA_HSYNC_WIDTH_LO, hsync_len & 0xff);
> +
> +       msleep(10);
> +
> +       /* cha, upper 2-bits of hsync_len */
> +       regmap_write(sn->regmap, SN65DSI_CHA_HSYNC_WIDTH_HI, (hsync_len >> 8) & 0xff);
> +
> +       msleep(10);
> +
> +       /* cha, lower 8-bits of vsync_len */
> +       regmap_write(sn->regmap, SN65DSI_CHA_VSYNC_WIDTH_LO, vsync_len & 0xff);
> +
> +       msleep(10);
> +
> +       /* cha, upper 2-bits of vsync_len */
> +       regmap_write(sn->regmap, SN65DSI_CHA_VSYNC_WIDTH_HI, (vsync_len >> 8) & 0xff);
> +
> +       msleep(10);
> +
> +       /* cha, hback_porch */
> +       regmap_write(sn->regmap, SN65DSI_CHA_HBACK_PORCH, hback_porch & 0xff);
> +
> +       msleep(10);
> +
> +       /* cha, vback_porch */
> +       regmap_write(sn->regmap, SN65DSI_CHA_VBACK_PORCH, vback_porch & 0xff);
> +
> +       msleep(10);
> +
> +       /* cha, hfront_porch */
> +       regmap_write(sn->regmap, SN65DSI_CHA_HFRONT_PORCH, hfront_porch & 0xff);
> +
> +       msleep(10);
> +
> +       /* cha, vfront_porch */
> +       regmap_write(sn->regmap, SN65DSI_CHA_VFRONT_PORCH, vfront_porch & 0xff);
> +
> +       msleep(10);
> +}
> +
> +static int sn65dsi_get_clk_range(int min, int max, unsigned long clock,
> +                                unsigned long start, unsigned long diff)
> +{
> +       unsigned long next;
> +       int i;
> +
> +       for (i = min; i <= max; i++) {
> +               next = start + diff;
> +               if (start <= clock && clock < next)
> +                       return i;
> +
> +               start += diff;
> +       }
> +
> +       return -EINVAL;
> +}
> +
> +static void sn65dsi_enable(struct drm_bridge *bridge)
> +{
> +       struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> +       struct drm_display_mode *mode = bridge_to_mode(bridge);
> +       int bpp = mipi_dsi_pixel_format_to_bpp(sn->dsi->format);
> +       unsigned int lanes = sn->dsi->lanes;
> +       unsigned int pixel_clk = mode->clock * 1000;
> +       unsigned int dsi_clk = pixel_clk * bpp / (lanes * 2);
> +       unsigned int val;
> +
> +       /* set SOFT_RESET bit */
> +       regmap_write(sn->regmap, SN65DSI_SOFT_RESET, SN65DSI_RESET_EN);
> +
> +       msleep(10);
> +
> +       /* set PLL_EN bit */
> +       regmap_write(sn->regmap, SN65DSI_CLK_PLL, 0x0);
> +
> +       msleep(10);
> +
> +       /* setup lvds clock */
> +       val = sn65dsi_get_clk_range(0, 5, pixel_clk, 25000000, 25000000);
> +       if (val < 0) {
> +               DRM_DEV_ERROR(sn->dev, "invalid LVDS clock range %d\n", val);
> +               return;
> +       }
> +
> +       regmap_update_bits(sn->regmap, SN65DSI_LVDS_CLK,
> +                          SN65DSI_LVDS_CLK_MASK,
> +                          val << SN65DSI_LVDS_CLK_SHIFT);
> +
> +       regmap_update_bits(sn->regmap, SN65DSI_LVDS_CLK,
> +                          SN65DSI_LVDS_CLK_SRC_DSI,
> +                          SN65DSI_LVDS_CLK_SRC_DSI);
> +
> +       msleep(10);
> +
> +       /* setup bridge clock divider */
> +       val = (dsi_clk / pixel_clk) - 1;
> +       regmap_update_bits(sn->regmap, SN65DSI_CLK_DIV,
> +                          SN65DSI_CLK_DIV_MASK,
> +                          val << SN65DSI_CLK_DIV_SHIFT);
> +       msleep(10);
> +
> +       /* configure dsi */
> +       regmap_update_bits(sn->regmap, SN65DSI_DSI_CFG,
> +                          SN65DSI_DSI_LANE_MASK,
> +                          lanes << SN65DSI_DSI_LANE_SHIFT);
> +       msleep(10);
> +

Most of those, look like. I don't know why it does not work without.
Where is mention in datasheet?

> +       /* dsi clock range */
> +       val = sn65dsi_get_clk_range(8, 100, dsi_clk, 40000000, 5000000);
> +       if (val < 0) {
> +               DRM_DEV_ERROR(sn->dev, "invalid DSI clock range %d\n", val);
> +               return;
> +       }
> +
> +       regmap_write(sn->regmap, SN65DSI_DSI_CLK_RANGE, val);
> +
> +       msleep(10);
> +
> +       /* setup lvds channels */
> +       regmap_read(sn->regmap, SN65DSI_LVDS_MODE, &val);
> +       if (bpp == 24)
> +               val |= SN65DSI_LVDS_CHA_24BPP;
> +       regmap_write(sn->regmap, SN65DSI_LVDS_MODE, val);
> +
> +       msleep(10);
> +
> +       /* TODO Channel B required to set up for dual-link LVDS */
> +       sn65dsi_setup_channels(sn, mode);
> +

If you are supporting 84 this code can be drop.

> +       /* set PLL_EN bit */
> +       regmap_write(sn->regmap, SN65DSI_CLK_PLL, SN65DSI_PLL_EN);
> +
> +       msleep(10);
> +}
> +
> +static void sn65dsi_disable(struct drm_bridge *bridge)
> +{
> +       struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> +
> +       /* set PLL_EN bit */
> +       regmap_write(sn->regmap, SN65DSI_CLK_PLL, 0x0);
> +
> +       msleep(10);
> +
> +       /* set SOFT_RESET bit */
> +       regmap_write(sn->regmap, SN65DSI_SOFT_RESET, 0x0);
> +
> +       msleep(10);
> +}
> +
> +static void sn65dsi_post_disable(struct drm_bridge *bridge)
> +{
> +       struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> +
> +       gpiod_set_value_cansleep(sn->enable, 1);
> +
> +       msleep(10);
> +
> +       gpiod_set_value_cansleep(sn->enable, 0);
> +
> +       msleep(10);
> +}
> +
> +static void sn65dsi_pre_enable(struct drm_bridge *bridge)
> +{
> +       struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> +
> +       gpiod_set_value_cansleep(sn->enable, 0);
> +
> +       msleep(10);
> +
> +       gpiod_set_value_cansleep(sn->enable, 1);
> +
> +       msleep(10);
> +}
> +
> +static int sn65dsi_attach(struct drm_bridge *bridge, enum drm_bridge_attach_flags flags)
> +{
> +       struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> +       struct mipi_dsi_host *host;
> +       struct mipi_dsi_device *dsi;
> +       const struct mipi_dsi_device_info info = { .type = "sn65dsi",
> +                                                  .channel = 0,
> +                                                  .node = NULL,
> +                                                };
> +       int ret;
> +
> +       host = of_find_mipi_dsi_host_by_node(sn->host_node);
> +       if (!host) {
> +               DRM_DEV_ERROR(sn->dev, "failed to find dsi host\n");
> +               return -EPROBE_DEFER;
> +       }
> +
> +       dsi = mipi_dsi_device_register_full(host, &info);
> +       if (IS_ERR(dsi)) {
> +               DRM_DEV_ERROR(sn->dev, "failed to create dsi device\n");
> +               return PTR_ERR(sn->dsi);
> +       }
> +
> +       sn->dsi = dsi;
> +       dsi->lanes = sn->dsi_lanes;
> +       dsi->format = MIPI_DSI_FMT_RGB888;
> +       dsi->mode_flags = MIPI_DSI_MODE_VIDEO;
> +
> +       ret = mipi_dsi_attach(dsi);
> +       if (ret) {
> +               DRM_DEV_ERROR(sn->dev, "failed to attach dsi host\n");
> +               goto err_dsi_attach;
> +       }
> +
> +       return drm_bridge_attach(bridge->encoder, sn->panel_bridge,
> +                                &sn->bridge, flags);
> +
> +err_dsi_attach:
> +       mipi_dsi_device_unregister(dsi);
> +       return ret;
> +}
> +
> +static const struct drm_bridge_funcs sn65dsi_bridge_funcs = {
> +       .attach         = sn65dsi_attach,
> +       .pre_enable     = sn65dsi_pre_enable,
> +       .enable         = sn65dsi_enable,
> +       .disable        = sn65dsi_disable,
> +       .post_disable   = sn65dsi_post_disable,
> +};
> +
> +static int sn65dsi_parse_dt(struct sn65dsi *sn)
> +{
> +       struct device *dev = sn->dev;
> +       struct device_node *endpoint, *parent;
> +       struct property *prop;
> +       struct drm_panel *panel;
> +       int len = 0;
> +       int ret;
> +
> +       sn->enable = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
> +       if (IS_ERR(sn->enable)) {
> +               DRM_DEV_ERROR(dev, "failed to get enable gpio\n");
> +               return PTR_ERR(sn->enable);
> +       }
> +
> +       ret = drm_of_find_panel_or_bridge(dev->of_node, 1, 0, &panel, NULL);
> +       if (ret < 0)
> +               return ret;
> +       if (!panel)
> +               return -ENODEV;
> +
> +       sn->panel_bridge = devm_drm_panel_bridge_add(dev, panel);
> +       if (IS_ERR(sn->panel_bridge))
> +               return PTR_ERR(sn->panel_bridge);
> +
> +       /*
> +        * To get the data-lanes of dsi, we need to access the port1 of dsi_out
> +        * from the port0 of bridge.
> +        */
> +       endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1);
> +       if (endpoint) {
> +               /* dsi_out node */
> +               parent = of_graph_get_remote_port_parent(endpoint);
> +               of_node_put(endpoint);
> +               if (parent) {
> +                       /* dsi port 1 */
> +                       endpoint = of_graph_get_endpoint_by_regs(parent, 1, -1);
> +                       of_node_put(parent);
> +                       if (endpoint) {
> +                               prop = of_find_property(endpoint, "data-lanes", &len);
> +                               of_node_put(endpoint);
> +                               if (!prop) {
> +                                       DRM_DEV_ERROR(dev, "failed to find data lane\n");
> +                                       return -EPROBE_DEFER;
> +                               }
> +                       }
> +               }
> +       }
> +
> +       sn->dsi_lanes = len / sizeof(u32);
> +       if (sn->dsi_lanes < 1 || sn->dsi_lanes > 4)
> +               return -EINVAL;
> +
> +       sn->host_node = of_graph_get_remote_node(dev->of_node, 0, 0);
> +       if (!sn->host_node)
> +               return -ENODEV;
> +
> +       of_node_put(sn->host_node);
> +
> +       return 0;
> +}
> +
> +static int sn65dsi_probe(struct i2c_client *client)
> +{
> +       struct sn65dsi *sn;
> +       int ret;
> +
> +       sn = devm_kzalloc(&client->dev, sizeof(*sn), GFP_KERNEL);
> +       if (!sn)
> +               return -ENOMEM;
> +
> +       i2c_set_clientdata(client, sn);
> +       sn->dev = &client->dev;
> +
> +       sn->regmap = devm_regmap_init_i2c(client, &sn65dsi_regmap_config);
> +       if (IS_ERR(sn->regmap)) {
> +               DRM_DEV_ERROR(&client->dev,
> +                             "regmap allocation failed (ret = %d)\n", ret);
> +               return PTR_ERR(sn->regmap);
> +       }
> +
> +       ret = sn65dsi_parse_dt(sn);
> +       if (ret)
> +               return ret;
> +
> +       sn->bridge.funcs = &sn65dsi_bridge_funcs;
> +       sn->bridge.of_node = client->dev.of_node;
> +
> +       drm_bridge_add(&sn->bridge);
> +
> +       return 0;
> +}
> +
> +static int sn65dsi_remove(struct i2c_client *client)
> +{
> +       struct sn65dsi *sn = i2c_get_clientdata(client);
> +
> +       drm_bridge_remove(&sn->bridge);
> +
> +       return 0;
> +}
> +
> +static struct i2c_device_id sn65dsi_i2c_id[] = {
> +       { "sn65dsi84", 0},
> +       { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(i2c, sn65dsi_i2c_id);
> +
> +static const struct of_device_id sn65dsi_match_table[] = {
> +       {.compatible = "ti,sn65dsi84"},
> +       { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, sn65dsi_match_table);
> +
> +static struct i2c_driver sn65dsi_driver = {
> +       .driver = {
> +               .name = "ti-sn65dsi84",
> +               .of_match_table = sn65dsi_match_table,
> +       },
> +       .probe_new = sn65dsi_probe,
> +       .remove = sn65dsi_remove,
> +       .id_table = sn65dsi_i2c_id,
> +};
> +module_i2c_driver(sn65dsi_driver);
> +
> +MODULE_AUTHOR("Jagan Teki <jagan@amarulasolutions.com>");
> +MODULE_DESCRIPTION("SN65DSI84 DSI to LVDS bridge");
> +MODULE_LICENSE("GPL v2");
> --
> 2.25.1
>
>
Jagan Teki Jan. 20, 2021, 11:29 a.m. UTC | #2 
On Wed, Jan 20, 2021 at 4:55 PM Michael Nazzareno Trimarchi
<michael@amarulasolutions.com> wrote:
>
> Hi Jagan
>
> On Wed, Jan 20, 2021 at 12:22 PM Jagan Teki <jagan@amarulasolutions.com> wrote:
> >
> > SN65DSI84 is a Single Channel DSI to Dual-link LVDS bridge from
> > Texas Instruments.
> >
> > SN65DSI83, SN65DSI85 are variants of the same family of bridge
> > controllers.
> >
> > Right now the bridge driver is supporting a single link, dual-link
> > support requires to initiate I2C Channel B registers.
> >
> > Tested with STM32MP1 MIPI DSI host design configuration.
> >
> > Signed-off-by: Matteo Lisi <matteo.lisi@engicam.com>
> > Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> > ---
> >  MAINTAINERS                           |   6 +
> >  drivers/gpu/drm/bridge/Kconfig        |  19 +
> >  drivers/gpu/drm/bridge/Makefile       |   1 +
> >  drivers/gpu/drm/bridge/ti-sn65dsi84.c | 488 ++++++++++++++++++++++++++
> >  4 files changed, 514 insertions(+)
> >  create mode 100644 drivers/gpu/drm/bridge/ti-sn65dsi84.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 12dd1fff2a39..44750ff7640c 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -5984,6 +5984,12 @@ S:       Maintained
> >  F:     Documentation/devicetree/bindings/display/ti/
> >  F:     drivers/gpu/drm/omapdrm/
> >
> > +DRM DRIVERS FOR TI SN65DSI84 DSI TO LVDS BRIDGE
> > +M:     Jagan Teki <jagan@amarulasolutions.com>
> > +S:     Maintained
> > +F:     Documentation/devicetree/bindings/display/bridge/ti,sn65dsi84.yaml
> > +F:     drivers/gpu/drm/bridge/ti-sn65dsi84.c
> > +
> >  DRM DRIVERS FOR V3D
> >  M:     Eric Anholt <eric@anholt.net>
> >  S:     Supported
> > diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> > index e4110d6ca7b3..6494881bffb3 100644
> > --- a/drivers/gpu/drm/bridge/Kconfig
> > +++ b/drivers/gpu/drm/bridge/Kconfig
> > @@ -232,6 +232,25 @@ config DRM_TI_TFP410
> >         help
> >           Texas Instruments TFP410 DVI/HDMI Transmitter driver
> >
> > +config DRM_TI_SN65DSI84
> > +       tristate "TI SN65DSI84 DSI to LVDS bridge"
> > +       depends on OF
> > +       select DRM_KMS_HELPER
> > +       select REGMAP_I2C
> > +       select DRM_PANEL
> > +       select DRM_MIPI_DSI
> > +       help
> > +         Texas Instruments SN65DSI84 Single Channel DSI to Dual-link LVDS
> > +         bridge driver.
> > +
> > +         Bridge decodes MIPI DSI 18bpp RGB666 and 240bpp RG888 packets and
> > +         converts the formatted video data stream to a FlatLink compatible
> > +         LVDS output operating at pixel clocks operating from 25 MHx to
> > +         154 MHz.
> > +
> > +         SN65DSI84 offers a Dual-Link LVDS, Single-Link LVDS interface with
> > +         four data lanes per link.
> > +
> >  config DRM_TI_SN65DSI86
> >         tristate "TI SN65DSI86 DSI to eDP bridge"
> >         depends on OF
> > diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> > index 86e7acc76f8d..3906052ef639 100644
> > --- a/drivers/gpu/drm/bridge/Makefile
> > +++ b/drivers/gpu/drm/bridge/Makefile
> > @@ -20,6 +20,7 @@ obj-$(CONFIG_DRM_TOSHIBA_TC358767) += tc358767.o
> >  obj-$(CONFIG_DRM_TOSHIBA_TC358768) += tc358768.o
> >  obj-$(CONFIG_DRM_TOSHIBA_TC358775) += tc358775.o
> >  obj-$(CONFIG_DRM_I2C_ADV7511) += adv7511/
> > +obj-$(CONFIG_DRM_TI_SN65DSI84) += ti-sn65dsi84.o
> >  obj-$(CONFIG_DRM_TI_SN65DSI86) += ti-sn65dsi86.o
> >  obj-$(CONFIG_DRM_TI_TFP410) += ti-tfp410.o
> >  obj-$(CONFIG_DRM_TI_TPD12S015) += ti-tpd12s015.o
> > diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi84.c b/drivers/gpu/drm/bridge/ti-sn65dsi84.c
> > new file mode 100644
> > index 000000000000..3ed1f9a7d898
> > --- /dev/null
> > +++ b/drivers/gpu/drm/bridge/ti-sn65dsi84.c
> > @@ -0,0 +1,488 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (c) 2021 Engicam srl
> > + * Copyright (C) 2021 Amarula Solutions(India)
> > + * Author: Jagan Teki <jagan@amarulasolutions.com>
> > + */
> > +
> > +#include <drm/drm_of.h>
> > +#include <drm/drm_panel.h>
> > +#include <drm/drm_print.h>
> > +#include <drm/drm_mipi_dsi.h>
> > +
> > +#include <linux/delay.h>
> > +#include <linux/gpio/consumer.h>
> > +#include <linux/i2c.h>
> > +#include <linux/module.h>
> > +#include <linux/regmap.h>
> > +
> > +/* sn65dsi84 registers */
> > +#define SN65DSI_SOFT_RESET             0x09
> > +#define SN65DSI_LVDS_CLK               0x0a
> > +#define SN65DSI_CLK_DIV                        0x0b
> > +#define SN65DSI_CLK_PLL                        0x0d
> > +#define SN65DSI_DSI_CFG                        0x10
> > +#define SN65DSI_DSI_CLK_EQ             0x11
> > +#define SN65DSI_DSI_CLK_RANGE          0x12
> > +#define SN65DSI_LVDS_MODE              0x18
> > +#define SN65DSI_CHA_LINE_LO            0x20
> > +#define SN65DSI_CHA_LINE_HI            0x21
> > +#define SN65DSI_CHA_VIRT_LO            0x24
> > +#define SN65DSI_CHA_VIRT_HI            0x25
> > +#define SN65DSI_CHA_SYNC_DELAY_LO      0x28
> > +#define SN65DSI_CHA_SYNC_DELAY_HI      0x29
> > +#define SN65DSI_CHA_HSYNC_WIDTH_LO     0x2c
> > +#define SN65DSI_CHA_HSYNC_WIDTH_HI     0x2d
> > +#define SN65DSI_CHA_VSYNC_WIDTH_LO     0x30
> > +#define SN65DSI_CHA_VSYNC_WIDTH_HI     0x31
> > +#define SN65DSI_CHA_HBACK_PORCH                0x34
> > +#define SN65DSI_CHA_VBACK_PORCH                0x36
> > +#define SN65DSI_CHA_HFRONT_PORCH       0x38
> > +#define SN65DSI_CHA_VFRONT_PORCH       0x3a
> > +#define SN65DSI_CHA_ERR                        0xe5
> > +
> > +/* sn65dsi register bits */
> > +#define SN65DSI_RESET_EN               BIT(0)
> > +#define SN65DSI_PLL_EN                 BIT(0)
> > +#define SN65DSI_LVDS_CLK_MASK          GENMASK(3, 1)
> > +#define SN65DSI_LVDS_CLK_SHIFT         1
> > +#define SN65DSI_LVDS_CLK_SRC_DSI       BIT(0)
> > +#define SN65DSI_CLK_DIV_MASK           GENMASK(7, 3)
> > +#define SN65DSI_CLK_DIV_SHIFT          3
> > +#define SN65DSI_DSI_LANE_MASK          GENMASK(4, 3)
> > +#define SN65DSI_DSI_LANE_SHIFT         3
> > +#define SN65DSI_LVDS_LINK_CFG          BIT(4)
> > +#define SN65DSI_LVDS_CHA_24BPP         BIT(3)
> > +#define SN65DSI_CHA_LOW_SYNC_DELAY     0x20
> > +#define SN65DSI_CHA_HIGH_SYNC_DELAY    0x00
> > +
> > +struct sn65dsi {
> > +       struct device                   *dev;
> > +       struct drm_bridge               bridge;
> > +       struct drm_bridge               *panel_bridge;
> > +
> > +       struct device_node              *host_node;
> > +       struct mipi_dsi_device          *dsi;
> > +       u8                              dsi_lanes;
> > +
> > +       struct regmap                   *regmap;
> > +       struct gpio_desc                *enable;
> > +};
> > +
> > +static const struct regmap_config sn65dsi_regmap_config = {
> > +       .reg_bits = 8,
> > +       .val_bits = 8,
> > +       .max_register = SN65DSI_CHA_ERR,
> > +       .name = "sn65dsi",
> > +       .cache_type = REGCACHE_RBTREE,
> > +};
> > +
> > +static inline struct sn65dsi *bridge_to_sn65dsi(struct drm_bridge *bridge)
> > +{
> > +       return container_of(bridge, struct sn65dsi, bridge);
> > +}
> > +
> > +static struct drm_display_mode *bridge_to_mode(struct drm_bridge *bridge)
> > +{
> > +       return &bridge->encoder->crtc->state->mode;
> > +}
> > +
> > +static void sn65dsi_setup_channels(struct sn65dsi *sn,
> > +                                  struct drm_display_mode *mode)
> > +{
> > +       u32 hsync_len, hfront_porch, hback_porch;
> > +       u32 vsync_len, vfront_porch, vback_porch;
> > +
> > +       hfront_porch = mode->hsync_start - mode->hdisplay;
> > +       hsync_len = mode->hsync_end - mode->hsync_start;
> > +       hback_porch = mode->htotal - mode->hsync_end;
> > +
> > +       vfront_porch = mode->vsync_start - mode->vdisplay;
> > +       vsync_len = mode->vsync_end - mode->vsync_start;
> > +       vback_porch = mode->vtotal - mode->vsync_end;
> > +
> > +       /* cha, lower 8-bits of hdisplay */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_LINE_LO, mode->hdisplay & 0xff);
> > +
> > +       msleep(10);
> > +
>
> I don't find any reason for those msleep. I don't have on my setup
> with the same bridge

As recommended by 8.2.2.1 Example Script from the datasheet.

https://www.ti.com/product/SN65DSI84

>
> > +       /* cha, upper 4-bits of hdisplay */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_LINE_HI, (mode->hdisplay >> 8) & 0xff);
> > +
> > +       msleep(10);
> > +
> > +       /* cha, lower 8-bits of vdisplay */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_VIRT_LO, mode->vdisplay & 0xff);
> > +
> > +       msleep(10);
> > +
> > +       /* cha, upper 4-bits of vdisplay */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_VIRT_HI, (mode->vdisplay >> 8) & 0xff);
> > +
> > +       msleep(10);
> > +
> > +       /*cha, lower sync delay */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_SYNC_DELAY_LO, SN65DSI_CHA_LOW_SYNC_DELAY);
> > +
> > +       msleep(10);
> > +
> > +       /*cha, upper sync delay */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_SYNC_DELAY_HI, SN65DSI_CHA_HIGH_SYNC_DELAY);
> > +
> > +       msleep(10);
> > +
> > +       /* cha, lower 8-bits of hsync_len */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_HSYNC_WIDTH_LO, hsync_len & 0xff);
> > +
> > +       msleep(10);
> > +
> > +       /* cha, upper 2-bits of hsync_len */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_HSYNC_WIDTH_HI, (hsync_len >> 8) & 0xff);
> > +
> > +       msleep(10);
> > +
> > +       /* cha, lower 8-bits of vsync_len */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_VSYNC_WIDTH_LO, vsync_len & 0xff);
> > +
> > +       msleep(10);
> > +
> > +       /* cha, upper 2-bits of vsync_len */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_VSYNC_WIDTH_HI, (vsync_len >> 8) & 0xff);
> > +
> > +       msleep(10);
> > +
> > +       /* cha, hback_porch */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_HBACK_PORCH, hback_porch & 0xff);
> > +
> > +       msleep(10);
> > +
> > +       /* cha, vback_porch */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_VBACK_PORCH, vback_porch & 0xff);
> > +
> > +       msleep(10);
> > +
> > +       /* cha, hfront_porch */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_HFRONT_PORCH, hfront_porch & 0xff);
> > +
> > +       msleep(10);
> > +
> > +       /* cha, vfront_porch */
> > +       regmap_write(sn->regmap, SN65DSI_CHA_VFRONT_PORCH, vfront_porch & 0xff);
> > +
> > +       msleep(10);
> > +}
> > +
> > +static int sn65dsi_get_clk_range(int min, int max, unsigned long clock,
> > +                                unsigned long start, unsigned long diff)
> > +{
> > +       unsigned long next;
> > +       int i;
> > +
> > +       for (i = min; i <= max; i++) {
> > +               next = start + diff;
> > +               if (start <= clock && clock < next)
> > +                       return i;
> > +
> > +               start += diff;
> > +       }
> > +
> > +       return -EINVAL;
> > +}
> > +
> > +static void sn65dsi_enable(struct drm_bridge *bridge)
> > +{
> > +       struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> > +       struct drm_display_mode *mode = bridge_to_mode(bridge);
> > +       int bpp = mipi_dsi_pixel_format_to_bpp(sn->dsi->format);
> > +       unsigned int lanes = sn->dsi->lanes;
> > +       unsigned int pixel_clk = mode->clock * 1000;
> > +       unsigned int dsi_clk = pixel_clk * bpp / (lanes * 2);
> > +       unsigned int val;
> > +
> > +       /* set SOFT_RESET bit */
> > +       regmap_write(sn->regmap, SN65DSI_SOFT_RESET, SN65DSI_RESET_EN);
> > +
> > +       msleep(10);
> > +
> > +       /* set PLL_EN bit */
> > +       regmap_write(sn->regmap, SN65DSI_CLK_PLL, 0x0);
> > +
> > +       msleep(10);
> > +
> > +       /* setup lvds clock */
> > +       val = sn65dsi_get_clk_range(0, 5, pixel_clk, 25000000, 25000000);
> > +       if (val < 0) {
> > +               DRM_DEV_ERROR(sn->dev, "invalid LVDS clock range %d\n", val);
> > +               return;
> > +       }
> > +
> > +       regmap_update_bits(sn->regmap, SN65DSI_LVDS_CLK,
> > +                          SN65DSI_LVDS_CLK_MASK,
> > +                          val << SN65DSI_LVDS_CLK_SHIFT);
> > +
> > +       regmap_update_bits(sn->regmap, SN65DSI_LVDS_CLK,
> > +                          SN65DSI_LVDS_CLK_SRC_DSI,
> > +                          SN65DSI_LVDS_CLK_SRC_DSI);
> > +
> > +       msleep(10);
> > +
> > +       /* setup bridge clock divider */
> > +       val = (dsi_clk / pixel_clk) - 1;
> > +       regmap_update_bits(sn->regmap, SN65DSI_CLK_DIV,
> > +                          SN65DSI_CLK_DIV_MASK,
> > +                          val << SN65DSI_CLK_DIV_SHIFT);
> > +       msleep(10);
> > +
> > +       /* configure dsi */
> > +       regmap_update_bits(sn->regmap, SN65DSI_DSI_CFG,
> > +                          SN65DSI_DSI_LANE_MASK,
> > +                          lanes << SN65DSI_DSI_LANE_SHIFT);
> > +       msleep(10);
> > +
>
> Most of those, look like. I don't know why it does not work without.
> Where is mention in datasheet?
>
> > +       /* dsi clock range */
> > +       val = sn65dsi_get_clk_range(8, 100, dsi_clk, 40000000, 5000000);
> > +       if (val < 0) {
> > +               DRM_DEV_ERROR(sn->dev, "invalid DSI clock range %d\n", val);
> > +               return;
> > +       }
> > +
> > +       regmap_write(sn->regmap, SN65DSI_DSI_CLK_RANGE, val);
> > +
> > +       msleep(10);
> > +
> > +       /* setup lvds channels */
> > +       regmap_read(sn->regmap, SN65DSI_LVDS_MODE, &val);
> > +       if (bpp == 24)
> > +               val |= SN65DSI_LVDS_CHA_24BPP;
> > +       regmap_write(sn->regmap, SN65DSI_LVDS_MODE, val);
> > +
> > +       msleep(10);
> > +
> > +       /* TODO Channel B required to set up for dual-link LVDS */
> > +       sn65dsi_setup_channels(sn, mode);
> > +
>
> If you are supporting 84 this code can be drop.

Right now the above function is setting up channel A for single-link
LVDS. 84 support Single and Dual link LVDS.

Jagan.
Michael Trimarchi Jan. 20, 2021, 11:55 a.m. UTC | #3 
On Wed, Jan 20, 2021 at 12:29 PM Jagan Teki <jagan@amarulasolutions.com> wrote:
>
> On Wed, Jan 20, 2021 at 4:55 PM Michael Nazzareno Trimarchi
> <michael@amarulasolutions.com> wrote:
> >
> > Hi Jagan
> >
> > On Wed, Jan 20, 2021 at 12:22 PM Jagan Teki <jagan@amarulasolutions.com> wrote:
> > >
> > > SN65DSI84 is a Single Channel DSI to Dual-link LVDS bridge from
> > > Texas Instruments.
> > >
> > > SN65DSI83, SN65DSI85 are variants of the same family of bridge
> > > controllers.
> > >
> > > Right now the bridge driver is supporting a single link, dual-link
> > > support requires to initiate I2C Channel B registers.
> > >
> > > Tested with STM32MP1 MIPI DSI host design configuration.
> > >
> > > Signed-off-by: Matteo Lisi <matteo.lisi@engicam.com>
> > > Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> > > ---
> > >  MAINTAINERS                           |   6 +
> > >  drivers/gpu/drm/bridge/Kconfig        |  19 +
> > >  drivers/gpu/drm/bridge/Makefile       |   1 +
> > >  drivers/gpu/drm/bridge/ti-sn65dsi84.c | 488 ++++++++++++++++++++++++++
> > >  4 files changed, 514 insertions(+)
> > >  create mode 100644 drivers/gpu/drm/bridge/ti-sn65dsi84.c
> > >
> > > diff --git a/MAINTAINERS b/MAINTAINERS
> > > index 12dd1fff2a39..44750ff7640c 100644
> > > --- a/MAINTAINERS
> > > +++ b/MAINTAINERS
> > > @@ -5984,6 +5984,12 @@ S:       Maintained
> > >  F:     Documentation/devicetree/bindings/display/ti/
> > >  F:     drivers/gpu/drm/omapdrm/
> > >
> > > +DRM DRIVERS FOR TI SN65DSI84 DSI TO LVDS BRIDGE
> > > +M:     Jagan Teki <jagan@amarulasolutions.com>
> > > +S:     Maintained
> > > +F:     Documentation/devicetree/bindings/display/bridge/ti,sn65dsi84.yaml
> > > +F:     drivers/gpu/drm/bridge/ti-sn65dsi84.c
> > > +
> > >  DRM DRIVERS FOR V3D
> > >  M:     Eric Anholt <eric@anholt.net>
> > >  S:     Supported
> > > diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> > > index e4110d6ca7b3..6494881bffb3 100644
> > > --- a/drivers/gpu/drm/bridge/Kconfig
> > > +++ b/drivers/gpu/drm/bridge/Kconfig
> > > @@ -232,6 +232,25 @@ config DRM_TI_TFP410
> > >         help
> > >           Texas Instruments TFP410 DVI/HDMI Transmitter driver
> > >
> > > +config DRM_TI_SN65DSI84
> > > +       tristate "TI SN65DSI84 DSI to LVDS bridge"
> > > +       depends on OF
> > > +       select DRM_KMS_HELPER
> > > +       select REGMAP_I2C
> > > +       select DRM_PANEL
> > > +       select DRM_MIPI_DSI
> > > +       help
> > > +         Texas Instruments SN65DSI84 Single Channel DSI to Dual-link LVDS
> > > +         bridge driver.
> > > +
> > > +         Bridge decodes MIPI DSI 18bpp RGB666 and 240bpp RG888 packets and
> > > +         converts the formatted video data stream to a FlatLink compatible
> > > +         LVDS output operating at pixel clocks operating from 25 MHx to
> > > +         154 MHz.
> > > +
> > > +         SN65DSI84 offers a Dual-Link LVDS, Single-Link LVDS interface with
> > > +         four data lanes per link.
> > > +
> > >  config DRM_TI_SN65DSI86
> > >         tristate "TI SN65DSI86 DSI to eDP bridge"
> > >         depends on OF
> > > diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> > > index 86e7acc76f8d..3906052ef639 100644
> > > --- a/drivers/gpu/drm/bridge/Makefile
> > > +++ b/drivers/gpu/drm/bridge/Makefile
> > > @@ -20,6 +20,7 @@ obj-$(CONFIG_DRM_TOSHIBA_TC358767) += tc358767.o
> > >  obj-$(CONFIG_DRM_TOSHIBA_TC358768) += tc358768.o
> > >  obj-$(CONFIG_DRM_TOSHIBA_TC358775) += tc358775.o
> > >  obj-$(CONFIG_DRM_I2C_ADV7511) += adv7511/
> > > +obj-$(CONFIG_DRM_TI_SN65DSI84) += ti-sn65dsi84.o
> > >  obj-$(CONFIG_DRM_TI_SN65DSI86) += ti-sn65dsi86.o
> > >  obj-$(CONFIG_DRM_TI_TFP410) += ti-tfp410.o
> > >  obj-$(CONFIG_DRM_TI_TPD12S015) += ti-tpd12s015.o
> > > diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi84.c b/drivers/gpu/drm/bridge/ti-sn65dsi84.c
> > > new file mode 100644
> > > index 000000000000..3ed1f9a7d898
> > > --- /dev/null
> > > +++ b/drivers/gpu/drm/bridge/ti-sn65dsi84.c
> > > @@ -0,0 +1,488 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +/*
> > > + * Copyright (c) 2021 Engicam srl
> > > + * Copyright (C) 2021 Amarula Solutions(India)
> > > + * Author: Jagan Teki <jagan@amarulasolutions.com>
> > > + */
> > > +
> > > +#include <drm/drm_of.h>
> > > +#include <drm/drm_panel.h>
> > > +#include <drm/drm_print.h>
> > > +#include <drm/drm_mipi_dsi.h>
> > > +
> > > +#include <linux/delay.h>
> > > +#include <linux/gpio/consumer.h>
> > > +#include <linux/i2c.h>
> > > +#include <linux/module.h>
> > > +#include <linux/regmap.h>
> > > +
> > > +/* sn65dsi84 registers */
> > > +#define SN65DSI_SOFT_RESET             0x09
> > > +#define SN65DSI_LVDS_CLK               0x0a
> > > +#define SN65DSI_CLK_DIV                        0x0b
> > > +#define SN65DSI_CLK_PLL                        0x0d
> > > +#define SN65DSI_DSI_CFG                        0x10
> > > +#define SN65DSI_DSI_CLK_EQ             0x11
> > > +#define SN65DSI_DSI_CLK_RANGE          0x12
> > > +#define SN65DSI_LVDS_MODE              0x18
> > > +#define SN65DSI_CHA_LINE_LO            0x20
> > > +#define SN65DSI_CHA_LINE_HI            0x21
> > > +#define SN65DSI_CHA_VIRT_LO            0x24
> > > +#define SN65DSI_CHA_VIRT_HI            0x25
> > > +#define SN65DSI_CHA_SYNC_DELAY_LO      0x28
> > > +#define SN65DSI_CHA_SYNC_DELAY_HI      0x29
> > > +#define SN65DSI_CHA_HSYNC_WIDTH_LO     0x2c
> > > +#define SN65DSI_CHA_HSYNC_WIDTH_HI     0x2d
> > > +#define SN65DSI_CHA_VSYNC_WIDTH_LO     0x30
> > > +#define SN65DSI_CHA_VSYNC_WIDTH_HI     0x31
> > > +#define SN65DSI_CHA_HBACK_PORCH                0x34
> > > +#define SN65DSI_CHA_VBACK_PORCH                0x36
> > > +#define SN65DSI_CHA_HFRONT_PORCH       0x38
> > > +#define SN65DSI_CHA_VFRONT_PORCH       0x3a
> > > +#define SN65DSI_CHA_ERR                        0xe5
> > > +
> > > +/* sn65dsi register bits */
> > > +#define SN65DSI_RESET_EN               BIT(0)
> > > +#define SN65DSI_PLL_EN                 BIT(0)
> > > +#define SN65DSI_LVDS_CLK_MASK          GENMASK(3, 1)
> > > +#define SN65DSI_LVDS_CLK_SHIFT         1
> > > +#define SN65DSI_LVDS_CLK_SRC_DSI       BIT(0)
> > > +#define SN65DSI_CLK_DIV_MASK           GENMASK(7, 3)
> > > +#define SN65DSI_CLK_DIV_SHIFT          3
> > > +#define SN65DSI_DSI_LANE_MASK          GENMASK(4, 3)
> > > +#define SN65DSI_DSI_LANE_SHIFT         3
> > > +#define SN65DSI_LVDS_LINK_CFG          BIT(4)
> > > +#define SN65DSI_LVDS_CHA_24BPP         BIT(3)
> > > +#define SN65DSI_CHA_LOW_SYNC_DELAY     0x20
> > > +#define SN65DSI_CHA_HIGH_SYNC_DELAY    0x00
> > > +
> > > +struct sn65dsi {
> > > +       struct device                   *dev;
> > > +       struct drm_bridge               bridge;
> > > +       struct drm_bridge               *panel_bridge;
> > > +
> > > +       struct device_node              *host_node;
> > > +       struct mipi_dsi_device          *dsi;
> > > +       u8                              dsi_lanes;
> > > +
> > > +       struct regmap                   *regmap;
> > > +       struct gpio_desc                *enable;
> > > +};
> > > +
> > > +static const struct regmap_config sn65dsi_regmap_config = {
> > > +       .reg_bits = 8,
> > > +       .val_bits = 8,
> > > +       .max_register = SN65DSI_CHA_ERR,
> > > +       .name = "sn65dsi",
> > > +       .cache_type = REGCACHE_RBTREE,
> > > +};
> > > +
> > > +static inline struct sn65dsi *bridge_to_sn65dsi(struct drm_bridge *bridge)
> > > +{
> > > +       return container_of(bridge, struct sn65dsi, bridge);
> > > +}
> > > +
> > > +static struct drm_display_mode *bridge_to_mode(struct drm_bridge *bridge)
> > > +{
> > > +       return &bridge->encoder->crtc->state->mode;
> > > +}
> > > +
> > > +static void sn65dsi_setup_channels(struct sn65dsi *sn,
> > > +                                  struct drm_display_mode *mode)
> > > +{
> > > +       u32 hsync_len, hfront_porch, hback_porch;
> > > +       u32 vsync_len, vfront_porch, vback_porch;
> > > +
> > > +       hfront_porch = mode->hsync_start - mode->hdisplay;
> > > +       hsync_len = mode->hsync_end - mode->hsync_start;
> > > +       hback_porch = mode->htotal - mode->hsync_end;
> > > +
> > > +       vfront_porch = mode->vsync_start - mode->vdisplay;
> > > +       vsync_len = mode->vsync_end - mode->vsync_start;
> > > +       vback_porch = mode->vtotal - mode->vsync_end;
> > > +
> > > +       /* cha, lower 8-bits of hdisplay */
> > > +       regmap_write(sn->regmap, SN65DSI_CHA_LINE_LO, mode->hdisplay & 0xff);
> > > +
> > > +       msleep(10);
> > > +
> >
> > I don't find any reason for those msleep. I don't have on my setup
> > with the same bridge
>
> As recommended by 8.2.2.1 Example Script from the datasheet.
>
> https://www.ti.com/product/SN65DSI84
>

Jurat wrap in one function and avoid, multiple msleep. Invesitgate
even if delay_us in regamp can be
used

Michael

> >
> > > +       /* cha, upper 4-bits of hdisplay */
> > > +       regmap_write(sn->regmap, SN65DSI_CHA_LINE_HI, (mode->hdisplay >> 8) & 0xff);
> > > +
> > > +       msleep(10);
> > > +
> > > +       /* cha, lower 8-bits of vdisplay */
> > > +       regmap_write(sn->regmap, SN65DSI_CHA_VIRT_LO, mode->vdisplay & 0xff);
> > > +
> > > +       msleep(10);
> > > +
> > > +       /* cha, upper 4-bits of vdisplay */
> > > +       regmap_write(sn->regmap, SN65DSI_CHA_VIRT_HI, (mode->vdisplay >> 8) & 0xff);
> > > +
> > > +       msleep(10);
> > > +
> > > +       /*cha, lower sync delay */
> > > +       regmap_write(sn->regmap, SN65DSI_CHA_SYNC_DELAY_LO, SN65DSI_CHA_LOW_SYNC_DELAY);
> > > +
> > > +       msleep(10);
> > > +
> > > +       /*cha, upper sync delay */
> > > +       regmap_write(sn->regmap, SN65DSI_CHA_SYNC_DELAY_HI, SN65DSI_CHA_HIGH_SYNC_DELAY);
> > > +
> > > +       msleep(10);
> > > +
> > > +       /* cha, lower 8-bits of hsync_len */
> > > +       regmap_write(sn->regmap, SN65DSI_CHA_HSYNC_WIDTH_LO, hsync_len & 0xff);
> > > +
> > > +       msleep(10);
> > > +
> > > +       /* cha, upper 2-bits of hsync_len */
> > > +       regmap_write(sn->regmap, SN65DSI_CHA_HSYNC_WIDTH_HI, (hsync_len >> 8) & 0xff);
> > > +
> > > +       msleep(10);
> > > +
> > > +       /* cha, lower 8-bits of vsync_len */
> > > +       regmap_write(sn->regmap, SN65DSI_CHA_VSYNC_WIDTH_LO, vsync_len & 0xff);
> > > +
> > > +       msleep(10);
> > > +
> > > +       /* cha, upper 2-bits of vsync_len */
> > > +       regmap_write(sn->regmap, SN65DSI_CHA_VSYNC_WIDTH_HI, (vsync_len >> 8) & 0xff);
> > > +
> > > +       msleep(10);
> > > +
> > > +       /* cha, hback_porch */
> > > +       regmap_write(sn->regmap, SN65DSI_CHA_HBACK_PORCH, hback_porch & 0xff);
> > > +
> > > +       msleep(10);
> > > +
> > > +       /* cha, vback_porch */
> > > +       regmap_write(sn->regmap, SN65DSI_CHA_VBACK_PORCH, vback_porch & 0xff);
> > > +
> > > +       msleep(10);
> > > +
> > > +       /* cha, hfront_porch */
> > > +       regmap_write(sn->regmap, SN65DSI_CHA_HFRONT_PORCH, hfront_porch & 0xff);
> > > +
> > > +       msleep(10);
> > > +
> > > +       /* cha, vfront_porch */
> > > +       regmap_write(sn->regmap, SN65DSI_CHA_VFRONT_PORCH, vfront_porch & 0xff);
> > > +
> > > +       msleep(10);
> > > +}
> > > +
> > > +static int sn65dsi_get_clk_range(int min, int max, unsigned long clock,
> > > +                                unsigned long start, unsigned long diff)
> > > +{
> > > +       unsigned long next;
> > > +       int i;
> > > +
> > > +       for (i = min; i <= max; i++) {
> > > +               next = start + diff;
> > > +               if (start <= clock && clock < next)
> > > +                       return i;
> > > +
> > > +               start += diff;
> > > +       }
> > > +
> > > +       return -EINVAL;
> > > +}
> > > +
> > > +static void sn65dsi_enable(struct drm_bridge *bridge)
> > > +{
> > > +       struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> > > +       struct drm_display_mode *mode = bridge_to_mode(bridge);
> > > +       int bpp = mipi_dsi_pixel_format_to_bpp(sn->dsi->format);
> > > +       unsigned int lanes = sn->dsi->lanes;
> > > +       unsigned int pixel_clk = mode->clock * 1000;
> > > +       unsigned int dsi_clk = pixel_clk * bpp / (lanes * 2);
> > > +       unsigned int val;
> > > +
> > > +       /* set SOFT_RESET bit */
> > > +       regmap_write(sn->regmap, SN65DSI_SOFT_RESET, SN65DSI_RESET_EN);
> > > +
> > > +       msleep(10);
> > > +
> > > +       /* set PLL_EN bit */
> > > +       regmap_write(sn->regmap, SN65DSI_CLK_PLL, 0x0);
> > > +
> > > +       msleep(10);
> > > +
> > > +       /* setup lvds clock */
> > > +       val = sn65dsi_get_clk_range(0, 5, pixel_clk, 25000000, 25000000);
> > > +       if (val < 0) {
> > > +               DRM_DEV_ERROR(sn->dev, "invalid LVDS clock range %d\n", val);
> > > +               return;
> > > +       }
> > > +
> > > +       regmap_update_bits(sn->regmap, SN65DSI_LVDS_CLK,
> > > +                          SN65DSI_LVDS_CLK_MASK,
> > > +                          val << SN65DSI_LVDS_CLK_SHIFT);
> > > +
> > > +       regmap_update_bits(sn->regmap, SN65DSI_LVDS_CLK,
> > > +                          SN65DSI_LVDS_CLK_SRC_DSI,
> > > +                          SN65DSI_LVDS_CLK_SRC_DSI);
> > > +
> > > +       msleep(10);
> > > +
> > > +       /* setup bridge clock divider */
> > > +       val = (dsi_clk / pixel_clk) - 1;
> > > +       regmap_update_bits(sn->regmap, SN65DSI_CLK_DIV,
> > > +                          SN65DSI_CLK_DIV_MASK,
> > > +                          val << SN65DSI_CLK_DIV_SHIFT);
> > > +       msleep(10);
> > > +
> > > +       /* configure dsi */
> > > +       regmap_update_bits(sn->regmap, SN65DSI_DSI_CFG,
> > > +                          SN65DSI_DSI_LANE_MASK,
> > > +                          lanes << SN65DSI_DSI_LANE_SHIFT);
> > > +       msleep(10);
> > > +
> >
> > Most of those, look like. I don't know why it does not work without.
> > Where is mention in datasheet?
> >
> > > +       /* dsi clock range */
> > > +       val = sn65dsi_get_clk_range(8, 100, dsi_clk, 40000000, 5000000);
> > > +       if (val < 0) {
> > > +               DRM_DEV_ERROR(sn->dev, "invalid DSI clock range %d\n", val);
> > > +               return;
> > > +       }
> > > +
> > > +       regmap_write(sn->regmap, SN65DSI_DSI_CLK_RANGE, val);
> > > +
> > > +       msleep(10);
> > > +
> > > +       /* setup lvds channels */
> > > +       regmap_read(sn->regmap, SN65DSI_LVDS_MODE, &val);
> > > +       if (bpp == 24)
> > > +               val |= SN65DSI_LVDS_CHA_24BPP;
> > > +       regmap_write(sn->regmap, SN65DSI_LVDS_MODE, val);
> > > +
> > > +       msleep(10);
> > > +
> > > +       /* TODO Channel B required to set up for dual-link LVDS */
> > > +       sn65dsi_setup_channels(sn, mode);
> > > +
> >
> > If you are supporting 84 this code can be drop.
>
> Right now the above function is setting up channel A for single-link
> LVDS. 84 support Single and Dual link LVDS.
>
> Jagan.
Riadh Ghaddab Feb. 17, 2021, 3:14 p.m. UTC | #4 
Hi Jagan,

On 20/01/2021 12:21, Jagan Teki wrote:
> SN65DSI84 is a Single Channel DSI to Dual-link LVDS bridge from
> Texas Instruments.
>
> SN65DSI83, SN65DSI85 are variants of the same family of bridge
> controllers.
>
> Right now the bridge driver is supporting a single link, dual-link
> support requires to initiate I2C Channel B registers.
>
> Tested with STM32MP1 MIPI DSI host design configuration.
Do you have the code to support the Dual channel LVDS feature ?
If not I recently developed the code for a board using sn65dsi84 with Dual
LVDS channel
> Signed-off-by: Matteo Lisi <matteo.lisi@engicam.com>
> Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> ---
>   MAINTAINERS                           |   6 +
>   drivers/gpu/drm/bridge/Kconfig        |  19 +
>   drivers/gpu/drm/bridge/Makefile       |   1 +
>   drivers/gpu/drm/bridge/ti-sn65dsi84.c | 488 ++++++++++++++++++++++++++
>   4 files changed, 514 insertions(+)
>   create mode 100644 drivers/gpu/drm/bridge/ti-sn65dsi84.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 12dd1fff2a39..44750ff7640c 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -5984,6 +5984,12 @@ S:	Maintained
>   F:	Documentation/devicetree/bindings/display/ti/
>   F:	drivers/gpu/drm/omapdrm/
>   
> +DRM DRIVERS FOR TI SN65DSI84 DSI TO LVDS BRIDGE
> +M:	Jagan Teki <jagan@amarulasolutions.com>
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/display/bridge/ti,sn65dsi84.yaml
> +F:	drivers/gpu/drm/bridge/ti-sn65dsi84.c
> +
>   DRM DRIVERS FOR V3D
>   M:	Eric Anholt <eric@anholt.net>
>   S:	Supported
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index e4110d6ca7b3..6494881bffb3 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -232,6 +232,25 @@ config DRM_TI_TFP410
>   	help
>   	  Texas Instruments TFP410 DVI/HDMI Transmitter driver
>   
> +config DRM_TI_SN65DSI84
> +	tristate "TI SN65DSI84 DSI to LVDS bridge"
> +	depends on OF
> +	select DRM_KMS_HELPER
> +	select REGMAP_I2C
> +	select DRM_PANEL
> +	select DRM_MIPI_DSI
> +	help
> +	  Texas Instruments SN65DSI84 Single Channel DSI to Dual-link LVDS
> +	  bridge driver.
> +
> +	  Bridge decodes MIPI DSI 18bpp RGB666 and 240bpp RG888 packets and
> +	  converts the formatted video data stream to a FlatLink compatible
> +	  LVDS output operating at pixel clocks operating from 25 MHx to
> +	  154 MHz.
> +
> +	  SN65DSI84 offers a Dual-Link LVDS, Single-Link LVDS interface with
> +	  four data lanes per link.
> +
>   config DRM_TI_SN65DSI86
>   	tristate "TI SN65DSI86 DSI to eDP bridge"
>   	depends on OF
> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> index 86e7acc76f8d..3906052ef639 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -20,6 +20,7 @@ obj-$(CONFIG_DRM_TOSHIBA_TC358767) += tc358767.o
>   obj-$(CONFIG_DRM_TOSHIBA_TC358768) += tc358768.o
>   obj-$(CONFIG_DRM_TOSHIBA_TC358775) += tc358775.o
>   obj-$(CONFIG_DRM_I2C_ADV7511) += adv7511/
> +obj-$(CONFIG_DRM_TI_SN65DSI84) += ti-sn65dsi84.o
>   obj-$(CONFIG_DRM_TI_SN65DSI86) += ti-sn65dsi86.o
>   obj-$(CONFIG_DRM_TI_TFP410) += ti-tfp410.o
>   obj-$(CONFIG_DRM_TI_TPD12S015) += ti-tpd12s015.o
> diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi84.c b/drivers/gpu/drm/bridge/ti-sn65dsi84.c
> new file mode 100644
> index 000000000000..3ed1f9a7d898
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/ti-sn65dsi84.c
> @@ -0,0 +1,488 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2021 Engicam srl
> + * Copyright (C) 2021 Amarula Solutions(India)
> + * Author: Jagan Teki <jagan@amarulasolutions.com>
> + */
> +
> +#include <drm/drm_of.h>
> +#include <drm/drm_panel.h>
> +#include <drm/drm_print.h>
> +#include <drm/drm_mipi_dsi.h>
> +
> +#include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +
> +/* sn65dsi84 registers */
> +#define SN65DSI_SOFT_RESET		0x09
> +#define SN65DSI_LVDS_CLK		0x0a
> +#define SN65DSI_CLK_DIV			0x0b
> +#define SN65DSI_CLK_PLL			0x0d
> +#define SN65DSI_DSI_CFG			0x10
> +#define SN65DSI_DSI_CLK_EQ		0x11
> +#define SN65DSI_DSI_CLK_RANGE		0x12
> +#define SN65DSI_LVDS_MODE		0x18
> +#define SN65DSI_CHA_LINE_LO		0x20
> +#define SN65DSI_CHA_LINE_HI		0x21
> +#define SN65DSI_CHA_VIRT_LO		0x24
> +#define SN65DSI_CHA_VIRT_HI		0x25
> +#define SN65DSI_CHA_SYNC_DELAY_LO	0x28
> +#define SN65DSI_CHA_SYNC_DELAY_HI	0x29
> +#define SN65DSI_CHA_HSYNC_WIDTH_LO	0x2c
> +#define SN65DSI_CHA_HSYNC_WIDTH_HI	0x2d
> +#define SN65DSI_CHA_VSYNC_WIDTH_LO	0x30
> +#define SN65DSI_CHA_VSYNC_WIDTH_HI	0x31
> +#define SN65DSI_CHA_HBACK_PORCH		0x34
> +#define SN65DSI_CHA_VBACK_PORCH		0x36
> +#define SN65DSI_CHA_HFRONT_PORCH	0x38
> +#define SN65DSI_CHA_VFRONT_PORCH	0x3a
> +#define SN65DSI_CHA_ERR			0xe5
> +
> +/* sn65dsi register bits */
> +#define SN65DSI_RESET_EN		BIT(0)
> +#define SN65DSI_PLL_EN			BIT(0)
> +#define SN65DSI_LVDS_CLK_MASK		GENMASK(3, 1)
> +#define SN65DSI_LVDS_CLK_SHIFT		1
> +#define SN65DSI_LVDS_CLK_SRC_DSI	BIT(0)
> +#define SN65DSI_CLK_DIV_MASK		GENMASK(7, 3)
> +#define SN65DSI_CLK_DIV_SHIFT		3
> +#define SN65DSI_DSI_LANE_MASK		GENMASK(4, 3)
> +#define SN65DSI_DSI_LANE_SHIFT		3
> +#define SN65DSI_LVDS_LINK_CFG		BIT(4)
> +#define SN65DSI_LVDS_CHA_24BPP		BIT(3)
> +#define SN65DSI_CHA_LOW_SYNC_DELAY	0x20
> +#define SN65DSI_CHA_HIGH_SYNC_DELAY	0x00
> +
> +struct sn65dsi {
> +	struct device			*dev;
> +	struct drm_bridge		bridge;
> +	struct drm_bridge		*panel_bridge;
> +
> +	struct device_node		*host_node;
> +	struct mipi_dsi_device		*dsi;
> +	u8				dsi_lanes;
> +
> +	struct regmap			*regmap;
> +	struct gpio_desc		*enable;
> +};
> +
> +static const struct regmap_config sn65dsi_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +	.max_register = SN65DSI_CHA_ERR,
> +	.name = "sn65dsi",
> +	.cache_type = REGCACHE_RBTREE,
> +};
> +
> +static inline struct sn65dsi *bridge_to_sn65dsi(struct drm_bridge *bridge)
> +{
> +	return container_of(bridge, struct sn65dsi, bridge);
> +}
> +
> +static struct drm_display_mode *bridge_to_mode(struct drm_bridge *bridge)
> +{
> +	return &bridge->encoder->crtc->state->mode;
> +}
> +
> +static void sn65dsi_setup_channels(struct sn65dsi *sn,
> +				   struct drm_display_mode *mode)
> +{
> +	u32 hsync_len, hfront_porch, hback_porch;
> +	u32 vsync_len, vfront_porch, vback_porch;
> +
> +	hfront_porch = mode->hsync_start - mode->hdisplay;
> +	hsync_len = mode->hsync_end - mode->hsync_start;
> +	hback_porch = mode->htotal - mode->hsync_end;
> +
> +	vfront_porch = mode->vsync_start - mode->vdisplay;
> +	vsync_len = mode->vsync_end - mode->vsync_start;
> +	vback_porch = mode->vtotal - mode->vsync_end;
> +
> +	/* cha, lower 8-bits of hdisplay */
> +	regmap_write(sn->regmap, SN65DSI_CHA_LINE_LO, mode->hdisplay & 0xff);
> +
> +	msleep(10);
> +
> +	/* cha, upper 4-bits of hdisplay */
> +	regmap_write(sn->regmap, SN65DSI_CHA_LINE_HI, (mode->hdisplay >> 8) & 0xff);
> +
> +	msleep(10);
> +
> +	/* cha, lower 8-bits of vdisplay */
> +	regmap_write(sn->regmap, SN65DSI_CHA_VIRT_LO, mode->vdisplay & 0xff);
> +
> +	msleep(10);
> +
> +	/* cha, upper 4-bits of vdisplay */
> +	regmap_write(sn->regmap, SN65DSI_CHA_VIRT_HI, (mode->vdisplay >> 8) & 0xff);
> +
> +	msleep(10);
> +
According to the datasheet, the Vertical active parameter are not 
needed. They are used only for
test pattern generation.
> +	/*cha, lower sync delay */
> +	regmap_write(sn->regmap, SN65DSI_CHA_SYNC_DELAY_LO, SN65DSI_CHA_LOW_SYNC_DELAY);
> +
> +	msleep(10);
> +
> +	/*cha, upper sync delay */
> +	regmap_write(sn->regmap, SN65DSI_CHA_SYNC_DELAY_HI, SN65DSI_CHA_HIGH_SYNC_DELAY);
> +
> +	msleep(10);
> +
> +	/* cha, lower 8-bits of hsync_len */
> +	regmap_write(sn->regmap, SN65DSI_CHA_HSYNC_WIDTH_LO, hsync_len & 0xff);
> +
> +	msleep(10);
> +
> +	/* cha, upper 2-bits of hsync_len */
> +	regmap_write(sn->regmap, SN65DSI_CHA_HSYNC_WIDTH_HI, (hsync_len >> 8) & 0xff);
> +
> +	msleep(10);
> +
> +	/* cha, lower 8-bits of vsync_len */
> +	regmap_write(sn->regmap, SN65DSI_CHA_VSYNC_WIDTH_LO, vsync_len & 0xff);
> +
> +	msleep(10);
> +
> +	/* cha, upper 2-bits of vsync_len */
> +	regmap_write(sn->regmap, SN65DSI_CHA_VSYNC_WIDTH_HI, (vsync_len >> 8) & 0xff);
> +
> +	msleep(10);
> +
> +	/* cha, hback_porch */
> +	regmap_write(sn->regmap, SN65DSI_CHA_HBACK_PORCH, hback_porch & 0xff);
> +
> +	msleep(10);
> +
> +	/* cha, vback_porch */
> +	regmap_write(sn->regmap, SN65DSI_CHA_VBACK_PORCH, vback_porch & 0xff);
> +
> +	msleep(10);
> +
> +	/* cha, hfront_porch */
> +	regmap_write(sn->regmap, SN65DSI_CHA_HFRONT_PORCH, hfront_porch & 0xff);
> +
> +	msleep(10);
> +
> +	/* cha, vfront_porch */
> +	regmap_write(sn->regmap, SN65DSI_CHA_VFRONT_PORCH, vfront_porch & 0xff);
> +
> +	msleep(10);
> +}
> +
> +static int sn65dsi_get_clk_range(int min, int max, unsigned long clock,
> +				 unsigned long start, unsigned long diff)
> +{
> +	unsigned long next;
> +	int i;
> +
> +	for (i = min; i <= max; i++) {
> +		next = start + diff;
> +		if (start <= clock && clock < next)
> +			return i;
> +
> +		start += diff;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static void sn65dsi_enable(struct drm_bridge *bridge)
> +{
> +	struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> +	struct drm_display_mode *mode = bridge_to_mode(bridge);
> +	int bpp = mipi_dsi_pixel_format_to_bpp(sn->dsi->format);
> +	unsigned int lanes = sn->dsi->lanes;
> +	unsigned int pixel_clk = mode->clock * 1000;
> +	unsigned int dsi_clk = pixel_clk * bpp / (lanes * 2);
> +	unsigned int val;
> +
> +	/* set SOFT_RESET bit */
> +	regmap_write(sn->regmap, SN65DSI_SOFT_RESET, SN65DSI_RESET_EN);
> +
> +	msleep(10);
> +
> +	/* set PLL_EN bit */
> +	regmap_write(sn->regmap, SN65DSI_CLK_PLL, 0x0);
> +
> +	msleep(10);
> +
> +	/* setup lvds clock */
> +	val = sn65dsi_get_clk_range(0, 5, pixel_clk, 25000000, 25000000);
> +	if (val < 0) {
> +		DRM_DEV_ERROR(sn->dev, "invalid LVDS clock range %d\n", val);
> +		return;
> +	}
> +
> +	regmap_update_bits(sn->regmap, SN65DSI_LVDS_CLK,
> +			   SN65DSI_LVDS_CLK_MASK,
> +			   val << SN65DSI_LVDS_CLK_SHIFT);
> +
> +	regmap_update_bits(sn->regmap, SN65DSI_LVDS_CLK,
> +			   SN65DSI_LVDS_CLK_SRC_DSI,
> +			   SN65DSI_LVDS_CLK_SRC_DSI);
> +
> +	msleep(10);
> +
> +	/* setup bridge clock divider */
> +	val = (dsi_clk / pixel_clk) - 1;
> +	regmap_update_bits(sn->regmap, SN65DSI_CLK_DIV,
> +			   SN65DSI_CLK_DIV_MASK,
> +			   val << SN65DSI_CLK_DIV_SHIFT);
> +	msleep(10);
> +
> +	/* configure dsi */
> +	regmap_update_bits(sn->regmap, SN65DSI_DSI_CFG,
> +			   SN65DSI_DSI_LANE_MASK,
> +			   lanes << SN65DSI_DSI_LANE_SHIFT);
> +	msleep(10);
> +
> +	/* dsi clock range */
> +	val = sn65dsi_get_clk_range(8, 100, dsi_clk, 40000000, 5000000);
> +	if (val < 0) {
> +		DRM_DEV_ERROR(sn->dev, "invalid DSI clock range %d\n", val);
> +		return;
> +	}
> +
> +	regmap_write(sn->regmap, SN65DSI_DSI_CLK_RANGE, val);
> +
> +	msleep(10);
> +
> +	/* setup lvds channels */
> +	regmap_read(sn->regmap, SN65DSI_LVDS_MODE, &val);
> +	if (bpp == 24)
> +		val |= SN65DSI_LVDS_CHA_24BPP;
> +	regmap_write(sn->regmap, SN65DSI_LVDS_MODE, val);
> +
> +	msleep(10);
> +
> +	/* TODO Channel B required to set up for dual-link LVDS */
> +	sn65dsi_setup_channels(sn, mode);
> +
> +	/* set PLL_EN bit */
> +	regmap_write(sn->regmap, SN65DSI_CLK_PLL, SN65DSI_PLL_EN);
> +
> +	msleep(10);
> +}
According to the initialization sequence from TI, setting up the channel 
parameters
and the PLL clock should be done while the DSI clk are in HS mode and 
the DSI data
lanes are in LP11 mode.
Shouldn't this be done in the pre-enable function ?
> +
> +static void sn65dsi_disable(struct drm_bridge *bridge)
> +{
> +	struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> +
> +	/* set PLL_EN bit */
> +	regmap_write(sn->regmap, SN65DSI_CLK_PLL, 0x0);
> +
> +	msleep(10);
> +
> +	/* set SOFT_RESET bit */
> +	regmap_write(sn->regmap, SN65DSI_SOFT_RESET, 0x0);
> +
> +	msleep(10);
> +}
> +
> +static void sn65dsi_post_disable(struct drm_bridge *bridge)
> +{
> +	struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> +
> +	gpiod_set_value_cansleep(sn->enable, 1);
> +
> +	msleep(10);
> +
> +	gpiod_set_value_cansleep(sn->enable, 0);
> +
> +	msleep(10);
> +}
> +
> +static void sn65dsi_pre_enable(struct drm_bridge *bridge)
> +{
> +	struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> +
> +	gpiod_set_value_cansleep(sn->enable, 0);
> +
> +	msleep(10);
> +
> +	gpiod_set_value_cansleep(sn->enable, 1);
> +
> +	msleep(10);
> +}
> +
> +static int sn65dsi_attach(struct drm_bridge *bridge, enum drm_bridge_attach_flags flags)
> +{
> +	struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> +	struct mipi_dsi_host *host;
> +	struct mipi_dsi_device *dsi;
> +	const struct mipi_dsi_device_info info = { .type = "sn65dsi",
> +						   .channel = 0,
> +						   .node = NULL,
> +						 };
> +	int ret;
> +
> +	host = of_find_mipi_dsi_host_by_node(sn->host_node);
> +	if (!host) {
> +		DRM_DEV_ERROR(sn->dev, "failed to find dsi host\n");
> +		return -EPROBE_DEFER;
> +	}
> +
> +	dsi = mipi_dsi_device_register_full(host, &info);
> +	if (IS_ERR(dsi)) {
> +		DRM_DEV_ERROR(sn->dev, "failed to create dsi device\n");
> +		return PTR_ERR(sn->dsi);
> +	}
> +
> +	sn->dsi = dsi;
> +	dsi->lanes = sn->dsi_lanes;
> +	dsi->format = MIPI_DSI_FMT_RGB888;
> +	dsi->mode_flags = MIPI_DSI_MODE_VIDEO;
> +
> +	ret = mipi_dsi_attach(dsi);
> +	if (ret) {
> +		DRM_DEV_ERROR(sn->dev, "failed to attach dsi host\n");
> +		goto err_dsi_attach;
> +	}
> +
> +	return drm_bridge_attach(bridge->encoder, sn->panel_bridge,
> +				 &sn->bridge, flags);
> +
> +err_dsi_attach:
> +	mipi_dsi_device_unregister(dsi);
> +	return ret;
> +}
> +
> +static const struct drm_bridge_funcs sn65dsi_bridge_funcs = {
> +	.attach		= sn65dsi_attach,
> +	.pre_enable	= sn65dsi_pre_enable,
> +	.enable		= sn65dsi_enable,
> +	.disable	= sn65dsi_disable,
> +	.post_disable	= sn65dsi_post_disable,
> +};
> +
> +static int sn65dsi_parse_dt(struct sn65dsi *sn)
> +{
> +	struct device *dev = sn->dev;
> +	struct device_node *endpoint, *parent;
> +	struct property *prop;
> +	struct drm_panel *panel;
> +	int len = 0;
> +	int ret;
> +
> +	sn->enable = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
> +	if (IS_ERR(sn->enable)) {
> +		DRM_DEV_ERROR(dev, "failed to get enable gpio\n");
> +		return PTR_ERR(sn->enable);
> +	}
> +
> +	ret = drm_of_find_panel_or_bridge(dev->of_node, 1, 0, &panel, NULL);
> +	if (ret < 0)
> +		return ret;
> +	if (!panel)
> +		return -ENODEV;
> +
> +	sn->panel_bridge = devm_drm_panel_bridge_add(dev, panel);
> +	if (IS_ERR(sn->panel_bridge))
> +		return PTR_ERR(sn->panel_bridge);
> +
> +	/*
> +	 * To get the data-lanes of dsi, we need to access the port1 of dsi_out
> +	 * from the port0 of bridge.
> +	 */
> +	endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1);
> +	if (endpoint) {
> +		/* dsi_out node */
> +		parent = of_graph_get_remote_port_parent(endpoint);
> +		of_node_put(endpoint);
> +		if (parent) {
> +			/* dsi port 1 */
> +			endpoint = of_graph_get_endpoint_by_regs(parent, 1, -1);
> +			of_node_put(parent);
> +			if (endpoint) {
> +				prop = of_find_property(endpoint, "data-lanes", &len);
> +				of_node_put(endpoint);
> +				if (!prop) {
> +					DRM_DEV_ERROR(dev, "failed to find data lane\n");
> +					return -EPROBE_DEFER;
> +				}
> +			}
> +		}
> +	}
> +
> +	sn->dsi_lanes = len / sizeof(u32);
> +	if (sn->dsi_lanes < 1 || sn->dsi_lanes > 4)
> +		return -EINVAL;
> +
> +	sn->host_node = of_graph_get_remote_node(dev->of_node, 0, 0);
> +	if (!sn->host_node)
> +		return -ENODEV;
> +
> +	of_node_put(sn->host_node);
> +
> +	return 0;
> +}
> +
> +static int sn65dsi_probe(struct i2c_client *client)
> +{
> +	struct sn65dsi *sn;
> +	int ret;
> +
> +	sn = devm_kzalloc(&client->dev, sizeof(*sn), GFP_KERNEL);
> +	if (!sn)
> +		return -ENOMEM;
> +
> +	i2c_set_clientdata(client, sn);
> +	sn->dev = &client->dev;
> +
> +	sn->regmap = devm_regmap_init_i2c(client, &sn65dsi_regmap_config);
> +	if (IS_ERR(sn->regmap)) {
> +		DRM_DEV_ERROR(&client->dev,
> +			      "regmap allocation failed (ret = %d)\n", ret);
> +		return PTR_ERR(sn->regmap);
> +	}
> +
> +	ret = sn65dsi_parse_dt(sn);
> +	if (ret)
> +		return ret;
> +
> +	sn->bridge.funcs = &sn65dsi_bridge_funcs;
> +	sn->bridge.of_node = client->dev.of_node;
> +
> +	drm_bridge_add(&sn->bridge);
> +
> +	return 0;
> +}
> +
> +static int sn65dsi_remove(struct i2c_client *client)
> +{
> +	struct sn65dsi *sn = i2c_get_clientdata(client);
> +
> +	drm_bridge_remove(&sn->bridge);
> +
> +	return 0;
> +}
> +
> +static struct i2c_device_id sn65dsi_i2c_id[] = {
> +	{ "sn65dsi84", 0},
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(i2c, sn65dsi_i2c_id);
> +
> +static const struct of_device_id sn65dsi_match_table[] = {
> +	{.compatible = "ti,sn65dsi84"},
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, sn65dsi_match_table);
> +
> +static struct i2c_driver sn65dsi_driver = {
> +	.driver = {
> +		.name = "ti-sn65dsi84",
> +		.of_match_table = sn65dsi_match_table,
> +	},
> +	.probe_new = sn65dsi_probe,
> +	.remove = sn65dsi_remove,
> +	.id_table = sn65dsi_i2c_id,
> +};
> +module_i2c_driver(sn65dsi_driver);
> +
> +MODULE_AUTHOR("Jagan Teki <jagan@amarulasolutions.com>");
> +MODULE_DESCRIPTION("SN65DSI84 DSI to LVDS bridge");
> +MODULE_LICENSE("GPL v2");
Jagan Teki Feb. 24, 2021, 2:29 p.m. UTC | #5 
Hi Riadh,

On Wed, Feb 17, 2021 at 8:44 PM Riadh Ghaddab <rghaddab@baylibre.com> wrote:
>
> Hi Jagan,
>
> On 20/01/2021 12:21, Jagan Teki wrote:
>
> SN65DSI84 is a Single Channel DSI to Dual-link LVDS bridge from
> Texas Instruments.
>
> SN65DSI83, SN65DSI85 are variants of the same family of bridge
> controllers.
>
> Right now the bridge driver is supporting a single link, dual-link
> support requires to initiate I2C Channel B registers.
>
> Tested with STM32MP1 MIPI DSI host design configuration.
>
> Do you have the code to support the Dual channel LVDS feature ?
> If not I recently developed the code for a board using sn65dsi84 with Dual
> LVDS channel

I have the basic one, but not have the proper hardware to verify
dual-link. Please have a look at V2 of similar patches. We will sort
out the driver so-that it can work with possible configurations.

>
> Signed-off-by: Matteo Lisi <matteo.lisi@engicam.com>
> Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> ---
>  MAINTAINERS                           |   6 +
>  drivers/gpu/drm/bridge/Kconfig        |  19 +
>  drivers/gpu/drm/bridge/Makefile       |   1 +
>  drivers/gpu/drm/bridge/ti-sn65dsi84.c | 488 ++++++++++++++++++++++++++
>  4 files changed, 514 insertions(+)
>  create mode 100644 drivers/gpu/drm/bridge/ti-sn65dsi84.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 12dd1fff2a39..44750ff7640c 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -5984,6 +5984,12 @@ S: Maintained
>  F: Documentation/devicetree/bindings/display/ti/
>  F: drivers/gpu/drm/omapdrm/
>
> +DRM DRIVERS FOR TI SN65DSI84 DSI TO LVDS BRIDGE
> +M: Jagan Teki <jagan@amarulasolutions.com>
> +S: Maintained
> +F: Documentation/devicetree/bindings/display/bridge/ti,sn65dsi84.yaml
> +F: drivers/gpu/drm/bridge/ti-sn65dsi84.c
> +
>  DRM DRIVERS FOR V3D
>  M: Eric Anholt <eric@anholt.net>
>  S: Supported
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index e4110d6ca7b3..6494881bffb3 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -232,6 +232,25 @@ config DRM_TI_TFP410
>   help
>    Texas Instruments TFP410 DVI/HDMI Transmitter driver
>
> +config DRM_TI_SN65DSI84
> + tristate "TI SN65DSI84 DSI to LVDS bridge"
> + depends on OF
> + select DRM_KMS_HELPER
> + select REGMAP_I2C
> + select DRM_PANEL
> + select DRM_MIPI_DSI
> + help
> +  Texas Instruments SN65DSI84 Single Channel DSI to Dual-link LVDS
> +  bridge driver.
> +
> +  Bridge decodes MIPI DSI 18bpp RGB666 and 240bpp RG888 packets and
> +  converts the formatted video data stream to a FlatLink compatible
> +  LVDS output operating at pixel clocks operating from 25 MHx to
> +  154 MHz.
> +
> +  SN65DSI84 offers a Dual-Link LVDS, Single-Link LVDS interface with
> +  four data lanes per link.
> +
>  config DRM_TI_SN65DSI86
>   tristate "TI SN65DSI86 DSI to eDP bridge"
>   depends on OF
> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> index 86e7acc76f8d..3906052ef639 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -20,6 +20,7 @@ obj-$(CONFIG_DRM_TOSHIBA_TC358767) += tc358767.o
>  obj-$(CONFIG_DRM_TOSHIBA_TC358768) += tc358768.o
>  obj-$(CONFIG_DRM_TOSHIBA_TC358775) += tc358775.o
>  obj-$(CONFIG_DRM_I2C_ADV7511) += adv7511/
> +obj-$(CONFIG_DRM_TI_SN65DSI84) += ti-sn65dsi84.o
>  obj-$(CONFIG_DRM_TI_SN65DSI86) += ti-sn65dsi86.o
>  obj-$(CONFIG_DRM_TI_TFP410) += ti-tfp410.o
>  obj-$(CONFIG_DRM_TI_TPD12S015) += ti-tpd12s015.o
> diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi84.c b/drivers/gpu/drm/bridge/ti-sn65dsi84.c
> new file mode 100644
> index 000000000000..3ed1f9a7d898
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/ti-sn65dsi84.c
> @@ -0,0 +1,488 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2021 Engicam srl
> + * Copyright (C) 2021 Amarula Solutions(India)
> + * Author: Jagan Teki <jagan@amarulasolutions.com>
> + */
> +
> +#include <drm/drm_of.h>
> +#include <drm/drm_panel.h>
> +#include <drm/drm_print.h>
> +#include <drm/drm_mipi_dsi.h>
> +
> +#include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +
> +/* sn65dsi84 registers */
> +#define SN65DSI_SOFT_RESET 0x09
> +#define SN65DSI_LVDS_CLK 0x0a
> +#define SN65DSI_CLK_DIV 0x0b
> +#define SN65DSI_CLK_PLL 0x0d
> +#define SN65DSI_DSI_CFG 0x10
> +#define SN65DSI_DSI_CLK_EQ 0x11
> +#define SN65DSI_DSI_CLK_RANGE 0x12
> +#define SN65DSI_LVDS_MODE 0x18
> +#define SN65DSI_CHA_LINE_LO 0x20
> +#define SN65DSI_CHA_LINE_HI 0x21
> +#define SN65DSI_CHA_VIRT_LO 0x24
> +#define SN65DSI_CHA_VIRT_HI 0x25
> +#define SN65DSI_CHA_SYNC_DELAY_LO 0x28
> +#define SN65DSI_CHA_SYNC_DELAY_HI 0x29
> +#define SN65DSI_CHA_HSYNC_WIDTH_LO 0x2c
> +#define SN65DSI_CHA_HSYNC_WIDTH_HI 0x2d
> +#define SN65DSI_CHA_VSYNC_WIDTH_LO 0x30
> +#define SN65DSI_CHA_VSYNC_WIDTH_HI 0x31
> +#define SN65DSI_CHA_HBACK_PORCH 0x34
> +#define SN65DSI_CHA_VBACK_PORCH 0x36
> +#define SN65DSI_CHA_HFRONT_PORCH 0x38
> +#define SN65DSI_CHA_VFRONT_PORCH 0x3a
> +#define SN65DSI_CHA_ERR 0xe5
> +
> +/* sn65dsi register bits */
> +#define SN65DSI_RESET_EN BIT(0)
> +#define SN65DSI_PLL_EN BIT(0)
> +#define SN65DSI_LVDS_CLK_MASK GENMASK(3, 1)
> +#define SN65DSI_LVDS_CLK_SHIFT 1
> +#define SN65DSI_LVDS_CLK_SRC_DSI BIT(0)
> +#define SN65DSI_CLK_DIV_MASK GENMASK(7, 3)
> +#define SN65DSI_CLK_DIV_SHIFT 3
> +#define SN65DSI_DSI_LANE_MASK GENMASK(4, 3)
> +#define SN65DSI_DSI_LANE_SHIFT 3
> +#define SN65DSI_LVDS_LINK_CFG BIT(4)
> +#define SN65DSI_LVDS_CHA_24BPP BIT(3)
> +#define SN65DSI_CHA_LOW_SYNC_DELAY 0x20
> +#define SN65DSI_CHA_HIGH_SYNC_DELAY 0x00
> +
> +struct sn65dsi {
> + struct device *dev;
> + struct drm_bridge bridge;
> + struct drm_bridge *panel_bridge;
> +
> + struct device_node *host_node;
> + struct mipi_dsi_device *dsi;
> + u8 dsi_lanes;
> +
> + struct regmap *regmap;
> + struct gpio_desc *enable;
> +};
> +
> +static const struct regmap_config sn65dsi_regmap_config = {
> + .reg_bits = 8,
> + .val_bits = 8,
> + .max_register = SN65DSI_CHA_ERR,
> + .name = "sn65dsi",
> + .cache_type = REGCACHE_RBTREE,
> +};
> +
> +static inline struct sn65dsi *bridge_to_sn65dsi(struct drm_bridge *bridge)
> +{
> + return container_of(bridge, struct sn65dsi, bridge);
> +}
> +
> +static struct drm_display_mode *bridge_to_mode(struct drm_bridge *bridge)
> +{
> + return &bridge->encoder->crtc->state->mode;
> +}
> +
> +static void sn65dsi_setup_channels(struct sn65dsi *sn,
> +   struct drm_display_mode *mode)
> +{
> + u32 hsync_len, hfront_porch, hback_porch;
> + u32 vsync_len, vfront_porch, vback_porch;
> +
> + hfront_porch = mode->hsync_start - mode->hdisplay;
> + hsync_len = mode->hsync_end - mode->hsync_start;
> + hback_porch = mode->htotal - mode->hsync_end;
> +
> + vfront_porch = mode->vsync_start - mode->vdisplay;
> + vsync_len = mode->vsync_end - mode->vsync_start;
> + vback_porch = mode->vtotal - mode->vsync_end;
> +
> + /* cha, lower 8-bits of hdisplay */
> + regmap_write(sn->regmap, SN65DSI_CHA_LINE_LO, mode->hdisplay & 0xff);
> +
> + msleep(10);
> +
> + /* cha, upper 4-bits of hdisplay */
> + regmap_write(sn->regmap, SN65DSI_CHA_LINE_HI, (mode->hdisplay >> 8) & 0xff);
> +
> + msleep(10);
> +
> + /* cha, lower 8-bits of vdisplay */
> + regmap_write(sn->regmap, SN65DSI_CHA_VIRT_LO, mode->vdisplay & 0xff);
> +
> + msleep(10);
> +
> + /* cha, upper 4-bits of vdisplay */
> + regmap_write(sn->regmap, SN65DSI_CHA_VIRT_HI, (mode->vdisplay >> 8) & 0xff);
> +
> + msleep(10);
> +
>
> According to the datasheet, the Vertical active parameter are not needed. They are used only for
> test pattern generation.

I will check this.

>
> + /*cha, lower sync delay */
> + regmap_write(sn->regmap, SN65DSI_CHA_SYNC_DELAY_LO, SN65DSI_CHA_LOW_SYNC_DELAY);
> +
> + msleep(10);
> +
> + /*cha, upper sync delay */
> + regmap_write(sn->regmap, SN65DSI_CHA_SYNC_DELAY_HI, SN65DSI_CHA_HIGH_SYNC_DELAY);
> +
> + msleep(10);
> +
> + /* cha, lower 8-bits of hsync_len */
> + regmap_write(sn->regmap, SN65DSI_CHA_HSYNC_WIDTH_LO, hsync_len & 0xff);
> +
> + msleep(10);
> +
> + /* cha, upper 2-bits of hsync_len */
> + regmap_write(sn->regmap, SN65DSI_CHA_HSYNC_WIDTH_HI, (hsync_len >> 8) & 0xff);
> +
> + msleep(10);
> +
> + /* cha, lower 8-bits of vsync_len */
> + regmap_write(sn->regmap, SN65DSI_CHA_VSYNC_WIDTH_LO, vsync_len & 0xff);
> +
> + msleep(10);
> +
> + /* cha, upper 2-bits of vsync_len */
> + regmap_write(sn->regmap, SN65DSI_CHA_VSYNC_WIDTH_HI, (vsync_len >> 8) & 0xff);
> +
> + msleep(10);
> +
> + /* cha, hback_porch */
> + regmap_write(sn->regmap, SN65DSI_CHA_HBACK_PORCH, hback_porch & 0xff);
> +
> + msleep(10);
> +
> + /* cha, vback_porch */
> + regmap_write(sn->regmap, SN65DSI_CHA_VBACK_PORCH, vback_porch & 0xff);
> +
> + msleep(10);
> +
> + /* cha, hfront_porch */
> + regmap_write(sn->regmap, SN65DSI_CHA_HFRONT_PORCH, hfront_porch & 0xff);
> +
> + msleep(10);
> +
> + /* cha, vfront_porch */
> + regmap_write(sn->regmap, SN65DSI_CHA_VFRONT_PORCH, vfront_porch & 0xff);
> +
> + msleep(10);
> +}
> +
> +static int sn65dsi_get_clk_range(int min, int max, unsigned long clock,
> + unsigned long start, unsigned long diff)
> +{
> + unsigned long next;
> + int i;
> +
> + for (i = min; i <= max; i++) {
> + next = start + diff;
> + if (start <= clock && clock < next)
> + return i;
> +
> + start += diff;
> + }
> +
> + return -EINVAL;
> +}
> +
> +static void sn65dsi_enable(struct drm_bridge *bridge)
> +{
> + struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
> + struct drm_display_mode *mode = bridge_to_mode(bridge);
> + int bpp = mipi_dsi_pixel_format_to_bpp(sn->dsi->format);
> + unsigned int lanes = sn->dsi->lanes;
> + unsigned int pixel_clk = mode->clock * 1000;
> + unsigned int dsi_clk = pixel_clk * bpp / (lanes * 2);
> + unsigned int val;
> +
> + /* set SOFT_RESET bit */
> + regmap_write(sn->regmap, SN65DSI_SOFT_RESET, SN65DSI_RESET_EN);
> +
> + msleep(10);
> +
> + /* set PLL_EN bit */
> + regmap_write(sn->regmap, SN65DSI_CLK_PLL, 0x0);
> +
> + msleep(10);
> +
> + /* setup lvds clock */
> + val = sn65dsi_get_clk_range(0, 5, pixel_clk, 25000000, 25000000);
> + if (val < 0) {
> + DRM_DEV_ERROR(sn->dev, "invalid LVDS clock range %d\n", val);
> + return;
> + }
> +
> + regmap_update_bits(sn->regmap, SN65DSI_LVDS_CLK,
> +   SN65DSI_LVDS_CLK_MASK,
> +   val << SN65DSI_LVDS_CLK_SHIFT);
> +
> + regmap_update_bits(sn->regmap, SN65DSI_LVDS_CLK,
> +   SN65DSI_LVDS_CLK_SRC_DSI,
> +   SN65DSI_LVDS_CLK_SRC_DSI);
> +
> + msleep(10);
> +
> + /* setup bridge clock divider */
> + val = (dsi_clk / pixel_clk) - 1;
> + regmap_update_bits(sn->regmap, SN65DSI_CLK_DIV,
> +   SN65DSI_CLK_DIV_MASK,
> +   val << SN65DSI_CLK_DIV_SHIFT);
> + msleep(10);
> +
> + /* configure dsi */
> + regmap_update_bits(sn->regmap, SN65DSI_DSI_CFG,
> +   SN65DSI_DSI_LANE_MASK,
> +   lanes << SN65DSI_DSI_LANE_SHIFT);
> + msleep(10);
> +
> + /* dsi clock range */
> + val = sn65dsi_get_clk_range(8, 100, dsi_clk, 40000000, 5000000);
> + if (val < 0) {
> + DRM_DEV_ERROR(sn->dev, "invalid DSI clock range %d\n", val);
> + return;
> + }
> +
> + regmap_write(sn->regmap, SN65DSI_DSI_CLK_RANGE, val);
> +
> + msleep(10);
> +
> + /* setup lvds channels */
> + regmap_read(sn->regmap, SN65DSI_LVDS_MODE, &val);
> + if (bpp == 24)
> + val |= SN65DSI_LVDS_CHA_24BPP;
> + regmap_write(sn->regmap, SN65DSI_LVDS_MODE, val);
> +
> + msleep(10);
> +
> + /* TODO Channel B required to set up for dual-link LVDS */
> + sn65dsi_setup_channels(sn, mode);
> +
> + /* set PLL_EN bit */
> + regmap_write(sn->regmap, SN65DSI_CLK_PLL, SN65DSI_PLL_EN);
> +
> + msleep(10);
> +}
>
> According to the initialization sequence from TI, setting up the channel parameters
> and the PLL clock should be done while the DSI clk are in HS mode and the DSI data
> lanes are in LP11 mode.
> Shouldn't this be done in the pre-enable function ?

I believe it doesn't matter as drm_atomic would pre_enable and enable
in sequence.  I have categories pre_enable for GPIO and the rest of
bridge initialization for enable code. Did you see any issues with
this setup, which DSI host are you using for it?

Jagan.

Patch
diff mbox series 

diff --git a/MAINTAINERS b/MAINTAINERS
index 12dd1fff2a39..44750ff7640c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5984,6 +5984,12 @@  S:	Maintained
 F:	Documentation/devicetree/bindings/display/ti/
 F:	drivers/gpu/drm/omapdrm/
 
+DRM DRIVERS FOR TI SN65DSI84 DSI TO LVDS BRIDGE
+M:	Jagan Teki <jagan@amarulasolutions.com>
+S:	Maintained
+F:	Documentation/devicetree/bindings/display/bridge/ti,sn65dsi84.yaml
+F:	drivers/gpu/drm/bridge/ti-sn65dsi84.c
+
 DRM DRIVERS FOR V3D
 M:	Eric Anholt <eric@anholt.net>
 S:	Supported
diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index e4110d6ca7b3..6494881bffb3 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -232,6 +232,25 @@  config DRM_TI_TFP410
 	help
 	  Texas Instruments TFP410 DVI/HDMI Transmitter driver
 
+config DRM_TI_SN65DSI84
+	tristate "TI SN65DSI84 DSI to LVDS bridge"
+	depends on OF
+	select DRM_KMS_HELPER
+	select REGMAP_I2C
+	select DRM_PANEL
+	select DRM_MIPI_DSI
+	help
+	  Texas Instruments SN65DSI84 Single Channel DSI to Dual-link LVDS
+	  bridge driver.
+
+	  Bridge decodes MIPI DSI 18bpp RGB666 and 240bpp RG888 packets and
+	  converts the formatted video data stream to a FlatLink compatible
+	  LVDS output operating at pixel clocks operating from 25 MHx to
+	  154 MHz.
+
+	  SN65DSI84 offers a Dual-Link LVDS, Single-Link LVDS interface with
+	  four data lanes per link.
+
 config DRM_TI_SN65DSI86
 	tristate "TI SN65DSI86 DSI to eDP bridge"
 	depends on OF
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
index 86e7acc76f8d..3906052ef639 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -20,6 +20,7 @@  obj-$(CONFIG_DRM_TOSHIBA_TC358767) += tc358767.o
 obj-$(CONFIG_DRM_TOSHIBA_TC358768) += tc358768.o
 obj-$(CONFIG_DRM_TOSHIBA_TC358775) += tc358775.o
 obj-$(CONFIG_DRM_I2C_ADV7511) += adv7511/
+obj-$(CONFIG_DRM_TI_SN65DSI84) += ti-sn65dsi84.o
 obj-$(CONFIG_DRM_TI_SN65DSI86) += ti-sn65dsi86.o
 obj-$(CONFIG_DRM_TI_TFP410) += ti-tfp410.o
 obj-$(CONFIG_DRM_TI_TPD12S015) += ti-tpd12s015.o
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi84.c b/drivers/gpu/drm/bridge/ti-sn65dsi84.c
new file mode 100644
index 000000000000..3ed1f9a7d898
--- /dev/null
+++ b/drivers/gpu/drm/bridge/ti-sn65dsi84.c
@@ -0,0 +1,488 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2021 Engicam srl
+ * Copyright (C) 2021 Amarula Solutions(India)
+ * Author: Jagan Teki <jagan@amarulasolutions.com>
+ */
+
+#include <drm/drm_of.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_print.h>
+#include <drm/drm_mipi_dsi.h>
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+/* sn65dsi84 registers */
+#define SN65DSI_SOFT_RESET		0x09
+#define SN65DSI_LVDS_CLK		0x0a
+#define SN65DSI_CLK_DIV			0x0b
+#define SN65DSI_CLK_PLL			0x0d
+#define SN65DSI_DSI_CFG			0x10
+#define SN65DSI_DSI_CLK_EQ		0x11
+#define SN65DSI_DSI_CLK_RANGE		0x12
+#define SN65DSI_LVDS_MODE		0x18
+#define SN65DSI_CHA_LINE_LO		0x20
+#define SN65DSI_CHA_LINE_HI		0x21
+#define SN65DSI_CHA_VIRT_LO		0x24
+#define SN65DSI_CHA_VIRT_HI		0x25
+#define SN65DSI_CHA_SYNC_DELAY_LO	0x28
+#define SN65DSI_CHA_SYNC_DELAY_HI	0x29
+#define SN65DSI_CHA_HSYNC_WIDTH_LO	0x2c
+#define SN65DSI_CHA_HSYNC_WIDTH_HI	0x2d
+#define SN65DSI_CHA_VSYNC_WIDTH_LO	0x30
+#define SN65DSI_CHA_VSYNC_WIDTH_HI	0x31
+#define SN65DSI_CHA_HBACK_PORCH		0x34
+#define SN65DSI_CHA_VBACK_PORCH		0x36
+#define SN65DSI_CHA_HFRONT_PORCH	0x38
+#define SN65DSI_CHA_VFRONT_PORCH	0x3a
+#define SN65DSI_CHA_ERR			0xe5
+
+/* sn65dsi register bits */
+#define SN65DSI_RESET_EN		BIT(0)
+#define SN65DSI_PLL_EN			BIT(0)
+#define SN65DSI_LVDS_CLK_MASK		GENMASK(3, 1)
+#define SN65DSI_LVDS_CLK_SHIFT		1
+#define SN65DSI_LVDS_CLK_SRC_DSI	BIT(0)
+#define SN65DSI_CLK_DIV_MASK		GENMASK(7, 3)
+#define SN65DSI_CLK_DIV_SHIFT		3
+#define SN65DSI_DSI_LANE_MASK		GENMASK(4, 3)
+#define SN65DSI_DSI_LANE_SHIFT		3
+#define SN65DSI_LVDS_LINK_CFG		BIT(4)
+#define SN65DSI_LVDS_CHA_24BPP		BIT(3)
+#define SN65DSI_CHA_LOW_SYNC_DELAY	0x20
+#define SN65DSI_CHA_HIGH_SYNC_DELAY	0x00
+
+struct sn65dsi {
+	struct device			*dev;
+	struct drm_bridge		bridge;
+	struct drm_bridge		*panel_bridge;
+
+	struct device_node		*host_node;
+	struct mipi_dsi_device		*dsi;
+	u8				dsi_lanes;
+
+	struct regmap			*regmap;
+	struct gpio_desc		*enable;
+};
+
+static const struct regmap_config sn65dsi_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = SN65DSI_CHA_ERR,
+	.name = "sn65dsi",
+	.cache_type = REGCACHE_RBTREE,
+};
+
+static inline struct sn65dsi *bridge_to_sn65dsi(struct drm_bridge *bridge)
+{
+	return container_of(bridge, struct sn65dsi, bridge);
+}
+
+static struct drm_display_mode *bridge_to_mode(struct drm_bridge *bridge)
+{
+	return &bridge->encoder->crtc->state->mode;
+}
+
+static void sn65dsi_setup_channels(struct sn65dsi *sn,
+				   struct drm_display_mode *mode)
+{
+	u32 hsync_len, hfront_porch, hback_porch;
+	u32 vsync_len, vfront_porch, vback_porch;
+
+	hfront_porch = mode->hsync_start - mode->hdisplay;
+	hsync_len = mode->hsync_end - mode->hsync_start;
+	hback_porch = mode->htotal - mode->hsync_end;
+
+	vfront_porch = mode->vsync_start - mode->vdisplay;
+	vsync_len = mode->vsync_end - mode->vsync_start;
+	vback_porch = mode->vtotal - mode->vsync_end;
+
+	/* cha, lower 8-bits of hdisplay */
+	regmap_write(sn->regmap, SN65DSI_CHA_LINE_LO, mode->hdisplay & 0xff);
+
+	msleep(10);
+
+	/* cha, upper 4-bits of hdisplay */
+	regmap_write(sn->regmap, SN65DSI_CHA_LINE_HI, (mode->hdisplay >> 8) & 0xff);
+
+	msleep(10);
+
+	/* cha, lower 8-bits of vdisplay */
+	regmap_write(sn->regmap, SN65DSI_CHA_VIRT_LO, mode->vdisplay & 0xff);
+
+	msleep(10);
+
+	/* cha, upper 4-bits of vdisplay */
+	regmap_write(sn->regmap, SN65DSI_CHA_VIRT_HI, (mode->vdisplay >> 8) & 0xff);
+
+	msleep(10);
+
+	/*cha, lower sync delay */
+	regmap_write(sn->regmap, SN65DSI_CHA_SYNC_DELAY_LO, SN65DSI_CHA_LOW_SYNC_DELAY);
+
+	msleep(10);
+
+	/*cha, upper sync delay */
+	regmap_write(sn->regmap, SN65DSI_CHA_SYNC_DELAY_HI, SN65DSI_CHA_HIGH_SYNC_DELAY);
+
+	msleep(10);
+
+	/* cha, lower 8-bits of hsync_len */
+	regmap_write(sn->regmap, SN65DSI_CHA_HSYNC_WIDTH_LO, hsync_len & 0xff);
+
+	msleep(10);
+
+	/* cha, upper 2-bits of hsync_len */
+	regmap_write(sn->regmap, SN65DSI_CHA_HSYNC_WIDTH_HI, (hsync_len >> 8) & 0xff);
+
+	msleep(10);
+
+	/* cha, lower 8-bits of vsync_len */
+	regmap_write(sn->regmap, SN65DSI_CHA_VSYNC_WIDTH_LO, vsync_len & 0xff);
+
+	msleep(10);
+
+	/* cha, upper 2-bits of vsync_len */
+	regmap_write(sn->regmap, SN65DSI_CHA_VSYNC_WIDTH_HI, (vsync_len >> 8) & 0xff);
+
+	msleep(10);
+
+	/* cha, hback_porch */
+	regmap_write(sn->regmap, SN65DSI_CHA_HBACK_PORCH, hback_porch & 0xff);
+
+	msleep(10);
+
+	/* cha, vback_porch */
+	regmap_write(sn->regmap, SN65DSI_CHA_VBACK_PORCH, vback_porch & 0xff);
+
+	msleep(10);
+
+	/* cha, hfront_porch */
+	regmap_write(sn->regmap, SN65DSI_CHA_HFRONT_PORCH, hfront_porch & 0xff);
+
+	msleep(10);
+
+	/* cha, vfront_porch */
+	regmap_write(sn->regmap, SN65DSI_CHA_VFRONT_PORCH, vfront_porch & 0xff);
+
+	msleep(10);
+}
+
+static int sn65dsi_get_clk_range(int min, int max, unsigned long clock,
+				 unsigned long start, unsigned long diff)
+{
+	unsigned long next;
+	int i;
+
+	for (i = min; i <= max; i++) {
+		next = start + diff;
+		if (start <= clock && clock < next)
+			return i;
+
+		start += diff;
+	}
+
+	return -EINVAL;
+}
+
+static void sn65dsi_enable(struct drm_bridge *bridge)
+{
+	struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
+	struct drm_display_mode *mode = bridge_to_mode(bridge);
+	int bpp = mipi_dsi_pixel_format_to_bpp(sn->dsi->format);
+	unsigned int lanes = sn->dsi->lanes;
+	unsigned int pixel_clk = mode->clock * 1000;
+	unsigned int dsi_clk = pixel_clk * bpp / (lanes * 2);
+	unsigned int val;
+
+	/* set SOFT_RESET bit */
+	regmap_write(sn->regmap, SN65DSI_SOFT_RESET, SN65DSI_RESET_EN);
+
+	msleep(10);
+
+	/* set PLL_EN bit */
+	regmap_write(sn->regmap, SN65DSI_CLK_PLL, 0x0);
+
+	msleep(10);
+
+	/* setup lvds clock */
+	val = sn65dsi_get_clk_range(0, 5, pixel_clk, 25000000, 25000000);
+	if (val < 0) {
+		DRM_DEV_ERROR(sn->dev, "invalid LVDS clock range %d\n", val);
+		return;
+	}
+
+	regmap_update_bits(sn->regmap, SN65DSI_LVDS_CLK,
+			   SN65DSI_LVDS_CLK_MASK,
+			   val << SN65DSI_LVDS_CLK_SHIFT);
+
+	regmap_update_bits(sn->regmap, SN65DSI_LVDS_CLK,
+			   SN65DSI_LVDS_CLK_SRC_DSI,
+			   SN65DSI_LVDS_CLK_SRC_DSI);
+
+	msleep(10);
+
+	/* setup bridge clock divider */
+	val = (dsi_clk / pixel_clk) - 1;
+	regmap_update_bits(sn->regmap, SN65DSI_CLK_DIV,
+			   SN65DSI_CLK_DIV_MASK,
+			   val << SN65DSI_CLK_DIV_SHIFT);
+	msleep(10);
+
+	/* configure dsi */
+	regmap_update_bits(sn->regmap, SN65DSI_DSI_CFG,
+			   SN65DSI_DSI_LANE_MASK,
+			   lanes << SN65DSI_DSI_LANE_SHIFT);
+	msleep(10);
+
+	/* dsi clock range */
+	val = sn65dsi_get_clk_range(8, 100, dsi_clk, 40000000, 5000000);
+	if (val < 0) {
+		DRM_DEV_ERROR(sn->dev, "invalid DSI clock range %d\n", val);
+		return;
+	}
+
+	regmap_write(sn->regmap, SN65DSI_DSI_CLK_RANGE, val);
+
+	msleep(10);
+
+	/* setup lvds channels */
+	regmap_read(sn->regmap, SN65DSI_LVDS_MODE, &val);
+	if (bpp == 24)
+		val |= SN65DSI_LVDS_CHA_24BPP;
+	regmap_write(sn->regmap, SN65DSI_LVDS_MODE, val);
+
+	msleep(10);
+
+	/* TODO Channel B required to set up for dual-link LVDS */
+	sn65dsi_setup_channels(sn, mode);
+
+	/* set PLL_EN bit */
+	regmap_write(sn->regmap, SN65DSI_CLK_PLL, SN65DSI_PLL_EN);
+
+	msleep(10);
+}
+
+static void sn65dsi_disable(struct drm_bridge *bridge)
+{
+	struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
+
+	/* set PLL_EN bit */
+	regmap_write(sn->regmap, SN65DSI_CLK_PLL, 0x0);
+
+	msleep(10);
+
+	/* set SOFT_RESET bit */
+	regmap_write(sn->regmap, SN65DSI_SOFT_RESET, 0x0);
+
+	msleep(10);
+}
+
+static void sn65dsi_post_disable(struct drm_bridge *bridge)
+{
+	struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
+
+	gpiod_set_value_cansleep(sn->enable, 1);
+
+	msleep(10);
+
+	gpiod_set_value_cansleep(sn->enable, 0);
+
+	msleep(10);
+}
+
+static void sn65dsi_pre_enable(struct drm_bridge *bridge)
+{
+	struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
+
+	gpiod_set_value_cansleep(sn->enable, 0);
+
+	msleep(10);
+
+	gpiod_set_value_cansleep(sn->enable, 1);
+
+	msleep(10);
+}
+
+static int sn65dsi_attach(struct drm_bridge *bridge, enum drm_bridge_attach_flags flags)
+{
+	struct sn65dsi *sn = bridge_to_sn65dsi(bridge);
+	struct mipi_dsi_host *host;
+	struct mipi_dsi_device *dsi;
+	const struct mipi_dsi_device_info info = { .type = "sn65dsi",
+						   .channel = 0,
+						   .node = NULL,
+						 };
+	int ret;
+
+	host = of_find_mipi_dsi_host_by_node(sn->host_node);
+	if (!host) {
+		DRM_DEV_ERROR(sn->dev, "failed to find dsi host\n");
+		return -EPROBE_DEFER;
+	}
+
+	dsi = mipi_dsi_device_register_full(host, &info);
+	if (IS_ERR(dsi)) {
+		DRM_DEV_ERROR(sn->dev, "failed to create dsi device\n");
+		return PTR_ERR(sn->dsi);
+	}
+
+	sn->dsi = dsi;
+	dsi->lanes = sn->dsi_lanes;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->mode_flags = MIPI_DSI_MODE_VIDEO;
+
+	ret = mipi_dsi_attach(dsi);
+	if (ret) {
+		DRM_DEV_ERROR(sn->dev, "failed to attach dsi host\n");
+		goto err_dsi_attach;
+	}
+
+	return drm_bridge_attach(bridge->encoder, sn->panel_bridge,
+				 &sn->bridge, flags);
+
+err_dsi_attach:
+	mipi_dsi_device_unregister(dsi);
+	return ret;
+}
+
+static const struct drm_bridge_funcs sn65dsi_bridge_funcs = {
+	.attach		= sn65dsi_attach,
+	.pre_enable	= sn65dsi_pre_enable,
+	.enable		= sn65dsi_enable,
+	.disable	= sn65dsi_disable,
+	.post_disable	= sn65dsi_post_disable,
+};
+
+static int sn65dsi_parse_dt(struct sn65dsi *sn)
+{
+	struct device *dev = sn->dev;
+	struct device_node *endpoint, *parent;
+	struct property *prop;
+	struct drm_panel *panel;
+	int len = 0;
+	int ret;
+
+	sn->enable = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
+	if (IS_ERR(sn->enable)) {
+		DRM_DEV_ERROR(dev, "failed to get enable gpio\n");
+		return PTR_ERR(sn->enable);
+	}
+
+	ret = drm_of_find_panel_or_bridge(dev->of_node, 1, 0, &panel, NULL);
+	if (ret < 0)
+		return ret;
+	if (!panel)
+		return -ENODEV;
+
+	sn->panel_bridge = devm_drm_panel_bridge_add(dev, panel);
+	if (IS_ERR(sn->panel_bridge))
+		return PTR_ERR(sn->panel_bridge);
+
+	/*
+	 * To get the data-lanes of dsi, we need to access the port1 of dsi_out
+	 * from the port0 of bridge.
+	 */
+	endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1);
+	if (endpoint) {
+		/* dsi_out node */
+		parent = of_graph_get_remote_port_parent(endpoint);
+		of_node_put(endpoint);
+		if (parent) {
+			/* dsi port 1 */
+			endpoint = of_graph_get_endpoint_by_regs(parent, 1, -1);
+			of_node_put(parent);
+			if (endpoint) {
+				prop = of_find_property(endpoint, "data-lanes", &len);
+				of_node_put(endpoint);
+				if (!prop) {
+					DRM_DEV_ERROR(dev, "failed to find data lane\n");
+					return -EPROBE_DEFER;
+				}
+			}
+		}
+	}
+
+	sn->dsi_lanes = len / sizeof(u32);
+	if (sn->dsi_lanes < 1 || sn->dsi_lanes > 4)
+		return -EINVAL;
+
+	sn->host_node = of_graph_get_remote_node(dev->of_node, 0, 0);
+	if (!sn->host_node)
+		return -ENODEV;
+
+	of_node_put(sn->host_node);
+
+	return 0;
+}
+
+static int sn65dsi_probe(struct i2c_client *client)
+{
+	struct sn65dsi *sn;
+	int ret;
+
+	sn = devm_kzalloc(&client->dev, sizeof(*sn), GFP_KERNEL);
+	if (!sn)
+		return -ENOMEM;
+
+	i2c_set_clientdata(client, sn);
+	sn->dev = &client->dev;
+
+	sn->regmap = devm_regmap_init_i2c(client, &sn65dsi_regmap_config);
+	if (IS_ERR(sn->regmap)) {
+		DRM_DEV_ERROR(&client->dev,
+			      "regmap allocation failed (ret = %d)\n", ret);
+		return PTR_ERR(sn->regmap);
+	}
+
+	ret = sn65dsi_parse_dt(sn);
+	if (ret)
+		return ret;
+
+	sn->bridge.funcs = &sn65dsi_bridge_funcs;
+	sn->bridge.of_node = client->dev.of_node;
+
+	drm_bridge_add(&sn->bridge);
+
+	return 0;
+}
+
+static int sn65dsi_remove(struct i2c_client *client)
+{
+	struct sn65dsi *sn = i2c_get_clientdata(client);
+
+	drm_bridge_remove(&sn->bridge);
+
+	return 0;
+}
+
+static struct i2c_device_id sn65dsi_i2c_id[] = {
+	{ "sn65dsi84", 0},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(i2c, sn65dsi_i2c_id);
+
+static const struct of_device_id sn65dsi_match_table[] = {
+	{.compatible = "ti,sn65dsi84"},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sn65dsi_match_table);
+
+static struct i2c_driver sn65dsi_driver = {
+	.driver = {
+		.name = "ti-sn65dsi84",
+		.of_match_table = sn65dsi_match_table,
+	},
+	.probe_new = sn65dsi_probe,
+	.remove = sn65dsi_remove,
+	.id_table = sn65dsi_i2c_id,
+};
+module_i2c_driver(sn65dsi_driver);
+
+MODULE_AUTHOR("Jagan Teki <jagan@amarulasolutions.com>");
+MODULE_DESCRIPTION("SN65DSI84 DSI to LVDS bridge");
+MODULE_LICENSE("GPL v2");