diff --git a/MAINTAINERS b/MAINTAINERS index a36df9ed283d..bd246991a3b0 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -4565,6 +4565,13 @@ S: Maintained F: drivers/scsi/BusLogic.* F: drivers/scsi/FlashPoint.* +BXCAN CAN NETWORK DRIVER +M: Dario Binacchi +L: linux-can@vger.kernel.org +S: Maintained +F: Documentation/devicetree/bindings/net/can/st,stm32-bxcan.yaml +F: drivers/net/can/bxcan.c + C-MEDIA CMI8788 DRIVER M: Clemens Ladisch L: alsa-devel@alsa-project.org (moderated for non-subscribers) diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig index cd34e8dc9394..3ceccafd701b 100644 --- a/drivers/net/can/Kconfig +++ b/drivers/net/can/Kconfig @@ -93,6 +93,18 @@ config CAN_AT91 This is a driver for the SoC CAN controller in Atmel's AT91SAM9263 and AT91SAM9X5 processors. +config CAN_BXCAN + tristate "STM32 Basic Extended CAN (bxCAN) devices" + depends on OF || ARCH_STM32 || COMPILE_TEST + depends on HAS_IOMEM + select CAN_RX_OFFLOAD + help + Say yes here to build support for the STMicroelectronics STM32 basic + extended CAN Controller (bxCAN). + + This driver can also be built as a module. If so, the module + will be called bxcan. + config CAN_CAN327 tristate "Serial / USB serial ELM327 based OBD-II Interfaces (can327)" depends on TTY diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile index 52b0f6e10668..ff8f76295d13 100644 --- a/drivers/net/can/Makefile +++ b/drivers/net/can/Makefile @@ -14,6 +14,7 @@ obj-y += usb/ obj-y += softing/ obj-$(CONFIG_CAN_AT91) += at91_can.o +obj-$(CONFIG_CAN_BXCAN) += bxcan.o obj-$(CONFIG_CAN_CAN327) += can327.o obj-$(CONFIG_CAN_CC770) += cc770/ obj-$(CONFIG_CAN_C_CAN) += c_can/ diff --git a/drivers/net/can/bxcan.c b/drivers/net/can/bxcan.c new file mode 100644 index 000000000000..7f8831aef9c9 --- /dev/null +++ b/drivers/net/can/bxcan.c @@ -0,0 +1,1110 @@ +// SPDX-License-Identifier: GPL-2.0 +// +// bxcan.c - STM32 Basic Extended CAN controller driver +// +// Copyright (c) 2022 Dario Binacchi +// + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define BXCAN_NAPI_WEIGHT 3 +#define BXCAN_TIMEOUT_US 10000 + +#define BXCAN_RX_MB_NUM 2 +#define BXCAN_TX_MB_NUM 3 + +/* Master control register (MCR) bits */ +#define BXCAN_MCR_DBF BIT(16) +#define BXCAN_MCR_RESET BIT(15) +#define BXCAN_MCR_TTCM BIT(7) +#define BXCAN_MCR_ABOM BIT(6) +#define BXCAN_MCR_AWUM BIT(5) +#define BXCAN_MCR_NART BIT(4) +#define BXCAN_MCR_RFLM BIT(3) +#define BXCAN_MCR_TXFP BIT(2) +#define BXCAN_MCR_SLEEP BIT(1) +#define BXCAN_MCR_INRQ BIT(0) + +/* Master status register (MSR) bits */ +#define BXCAN_MSR_RX BIT(11) +#define BXCAN_MSR_SAMP BIT(10) +#define BXCAN_MSR_RXM BIT(9) +#define BXCAN_MSR_TXM BIT(8) +#define BXCAN_MSR_SLAKI BIT(4) +#define BXCAN_MSR_WKUI BIT(3) +#define BXCAN_MSR_ERRI BIT(2) +#define BXCAN_MSR_SLAK BIT(1) +#define BXCAN_MSR_INAK BIT(0) + +/* Transmit status register (TSR) bits */ +#define BXCAN_TSR_LOW2 BIT(31) +#define BXCAN_TSR_LOW1 BIT(30) +#define BXCAN_TSR_LOW0 BIT(29) +#define BXCAN_TSR_TME_MASK GENMASK(28, 26) +#define BXCAN_TSR_TME2 BIT(28) +#define BXCAN_TSR_TME1 BIT(27) +#define BXCAN_TSR_TME0 BIT(26) +#define BXCAN_TSR_CODE_MASK GENMASK(25, 24) +#define BXCAN_TSR_ABRQ2 BIT(23) +#define BXCAN_TSR_TERR2 BIT(19) +#define BXCAN_TSR_ALST2 BIT(18) +#define BXCAN_TSR_TXOK2 BIT(17) +#define BXCAN_TSR_RQCP2 BIT(16) +#define BXCAN_TSR_ABRQ1 BIT(15) +#define BXCAN_TSR_TERR1 BIT(11) +#define BXCAN_TSR_ALST1 BIT(10) +#define BXCAN_TSR_TXOK1 BIT(9) +#define BXCAN_TSR_RQCP1 BIT(8) +#define BXCAN_TSR_ABRQ0 BIT(7) +#define BXCAN_TSR_TERR0 BIT(3) +#define BXCAN_TSR_ALST0 BIT(2) +#define BXCAN_TSR_TXOK0 BIT(1) +#define BXCAN_TSR_RQCP0 BIT(0) + +/* Receive FIFO 0 register (RF0R) bits */ +#define BXCAN_RF0R_RFOM0 BIT(5) +#define BXCAN_RF0R_FOVR0 BIT(4) +#define BXCAN_RF0R_FULL0 BIT(3) +#define BXCAN_RF0R_FMP0_MASK GENMASK(1, 0) + +/* Interrupt enable register (IER) bits */ +#define BXCAN_IER_SLKIE BIT(17) +#define BXCAN_IER_WKUIE BIT(16) +#define BXCAN_IER_ERRIE BIT(15) +#define BXCAN_IER_LECIE BIT(11) +#define BXCAN_IER_BOFIE BIT(10) +#define BXCAN_IER_EPVIE BIT(9) +#define BXCAN_IER_EWGIE BIT(8) +#define BXCAN_IER_FOVIE1 BIT(6) +#define BXCAN_IER_FFIE1 BIT(5) +#define BXCAN_IER_FMPIE1 BIT(4) +#define BXCAN_IER_FOVIE0 BIT(3) +#define BXCAN_IER_FFIE0 BIT(2) +#define BXCAN_IER_FMPIE0 BIT(1) +#define BXCAN_IER_TMEIE BIT(0) + +/* Error status register (ESR) bits */ +#define BXCAN_ESR_REC_MASK GENMASK(31, 24) +#define BXCAN_ESR_TEC_MASK GENMASK(23, 16) +#define BXCAN_ESR_LEC_MASK GENMASK(6, 4) +#define BXCAN_ESR_BOFF BIT(2) +#define BXCAN_ESR_EPVF BIT(1) +#define BXCAN_ESR_EWGF BIT(0) + +/* Bit timing register (BTR) bits */ +#define BXCAN_BTR_SILM BIT(31) +#define BXCAN_BTR_LBKM BIT(30) +#define BXCAN_BTR_SJW_MASK GENMASK(25, 24) +#define BXCAN_BTR_TS2_MASK GENMASK(22, 20) +#define BXCAN_BTR_TS1_MASK GENMASK(19, 16) +#define BXCAN_BTR_BRP_MASK GENMASK(9, 0) + +/* TX mailbox identifier register (TIxR, x = 0..2) bits */ +#define BXCAN_TIxR_STID_MASK GENMASK(31, 21) +#define BXCAN_TIxR_EXID_MASK GENMASK(31, 3) +#define BXCAN_TIxR_IDE BIT(2) +#define BXCAN_TIxR_RTR BIT(1) +#define BXCAN_TIxR_TXRQ BIT(0) + +/* TX mailbox data length and time stamp register (TDTxR, x = 0..2 bits */ +#define BXCAN_TDTxR_TIME_MASK GENMASK(31, 16) +#define BXCAN_TDTxR_TGT BIT(8) +#define BXCAN_TDTxR_DLC_MASK GENMASK(3, 0) + +/* RX FIFO mailbox identifier register (RIxR, x = 0..1 */ +#define BXCAN_RIxR_STID_MASK GENMASK(31, 21) +#define BXCAN_RIxR_EXID_MASK GENMASK(31, 3) +#define BXCAN_RIxR_IDE BIT(2) +#define BXCAN_RIxR_RTR BIT(1) + +/* RX FIFO mailbox data length and timestamp register (RDTxR, x = 0..1) bits */ +#define BXCAN_RDTxR_TIME_MASK GENMASK(31, 16) +#define BXCAN_RDTxR_FMI_MASK GENMASK(15, 8) +#define BXCAN_RDTxR_DLC_MASK GENMASK(3, 0) + +#define BXCAN_FMR_REG 0x00 +#define BXCAN_FM1R_REG 0x04 +#define BXCAN_FS1R_REG 0x0c +#define BXCAN_FFA1R_REG 0x14 +#define BXCAN_FA1R_REG 0x1c +#define BXCAN_FiR1_REG(b) (0x40 + (b) * 8) +#define BXCAN_FiR2_REG(b) (0x44 + (b) * 8) + +#define BXCAN_FILTER_ID(master) (master ? 0 : 14) + +/* Filter master register (FMR) bits */ +#define BXCAN_FMR_CANSB_MASK GENMASK(13, 8) +#define BXCAN_FMR_FINIT BIT(0) + +enum bxcan_lec_code { + BXCAN_LEC_NO_ERROR = 0, + BXCAN_LEC_STUFF_ERROR, + BXCAN_LEC_FORM_ERROR, + BXCAN_LEC_ACK_ERROR, + BXCAN_LEC_BIT1_ERROR, + BXCAN_LEC_BIT0_ERROR, + BXCAN_LEC_CRC_ERROR, + BXCAN_LEC_UNUSED +}; + +/* Structure of the message buffer */ +struct bxcan_mb { + u32 id; /* can identifier */ + u32 dlc; /* data length control and timestamp */ + u32 data[2]; /* data */ +}; + +/* Structure of the hardware registers */ +struct bxcan_regs { + u32 mcr; /* 0x00 - master control */ + u32 msr; /* 0x04 - master status */ + u32 tsr; /* 0x08 - transmit status */ + u32 rf0r; /* 0x0c - FIFO 0 */ + u32 rf1r; /* 0x10 - FIFO 1 */ + u32 ier; /* 0x14 - interrupt enable */ + u32 esr; /* 0x18 - error status */ + u32 btr; /* 0x1c - bit timing*/ + u32 reserved0[88]; /* 0x20 */ + struct bxcan_mb tx_mb[BXCAN_TX_MB_NUM]; /* 0x180 - tx mailbox */ + struct bxcan_mb rx_mb[BXCAN_RX_MB_NUM]; /* 0x1b0 - rx mailbox */ +}; + +struct bxcan_priv { + struct can_priv can; + struct can_rx_offload offload; + struct device *dev; + struct net_device *ndev; + + struct bxcan_regs __iomem *regs; + struct regmap *gcan; + int tx_irq; + int sce_irq; + bool master; + struct clk *clk; + spinlock_t rmw_lock; /* lock for read-modify-write operations */ + unsigned int tx_head; + unsigned int tx_tail; + u32 timestamp; +}; + +static const struct can_bittiming_const bxcan_bittiming_const = { + .name = KBUILD_MODNAME, + .tseg1_min = 1, + .tseg1_max = 16, + .tseg2_min = 1, + .tseg2_max = 8, + .sjw_max = 4, + .brp_min = 1, + .brp_max = 1024, + .brp_inc = 1, +}; + +static inline void bxcan_rmw(struct bxcan_priv *priv, void __iomem *addr, + u32 clear, u32 set) +{ + unsigned long flags; + u32 old, val; + + spin_lock_irqsave(&priv->rmw_lock, flags); + old = readl(addr); + val = (old & ~clear) | set; + if (val != old) + writel(val, addr); + + spin_unlock_irqrestore(&priv->rmw_lock, flags); +} + +static void bxcan_disable_filters(struct bxcan_priv *priv, bool master) +{ + unsigned int fid = BXCAN_FILTER_ID(master); + u32 fmask = BIT(fid); + + regmap_update_bits(priv->gcan, BXCAN_FA1R_REG, fmask, 0); +} + +static void bxcan_enable_filters(struct bxcan_priv *priv, bool master) +{ + unsigned int fid = BXCAN_FILTER_ID(master); + u32 fmask = BIT(fid); + + /* Filter settings: + * + * Accept all messages. + * Assign filter 0 to CAN1 and filter 14 to CAN2 in identifier + * mask mode with 32 bits width. + */ + + /* Enter filter initialization mode and assing filters to CAN + * controllers. + */ + regmap_update_bits(priv->gcan, BXCAN_FMR_REG, + BXCAN_FMR_CANSB_MASK | BXCAN_FMR_FINIT, + FIELD_PREP(BXCAN_FMR_CANSB_MASK, 14) | + BXCAN_FMR_FINIT); + + /* Deactivate filter */ + regmap_update_bits(priv->gcan, BXCAN_FA1R_REG, fmask, 0); + + /* Two 32-bit registers in identifier mask mode */ + regmap_update_bits(priv->gcan, BXCAN_FM1R_REG, fmask, 0); + + /* Single 32-bit scale configuration */ + regmap_update_bits(priv->gcan, BXCAN_FS1R_REG, fmask, fmask); + + /* Assign filter to FIFO 0 */ + regmap_update_bits(priv->gcan, BXCAN_FFA1R_REG, fmask, 0); + + /* Accept all messages */ + regmap_write(priv->gcan, BXCAN_FiR1_REG(fid), 0); + regmap_write(priv->gcan, BXCAN_FiR2_REG(fid), 0); + + /* Activate filter */ + regmap_update_bits(priv->gcan, BXCAN_FA1R_REG, fmask, fmask); + + /* Exit filter initialization mode */ + regmap_update_bits(priv->gcan, BXCAN_FMR_REG, BXCAN_FMR_FINIT, 0); +} + +static inline u8 bxcan_get_tx_head(const struct bxcan_priv *priv) +{ + return priv->tx_head % BXCAN_TX_MB_NUM; +} + +static inline u8 bxcan_get_tx_tail(const struct bxcan_priv *priv) +{ + return priv->tx_tail % BXCAN_TX_MB_NUM; +} + +static inline u8 bxcan_get_tx_free(const struct bxcan_priv *priv) +{ + return BXCAN_TX_MB_NUM - (priv->tx_head - priv->tx_tail); +} + +static bool bxcan_tx_busy(const struct bxcan_priv *priv) +{ + if (bxcan_get_tx_free(priv) > 0) + return false; + + netif_stop_queue(priv->ndev); + + /* Memory barrier before checking tx_free (head and tail) */ + smp_mb(); + + if (bxcan_get_tx_free(priv) == 0) { + netdev_dbg(priv->ndev, + "Stopping tx-queue (tx_head=0x%08x, tx_tail=0x%08x, len=%d).\n", + priv->tx_head, priv->tx_tail, + priv->tx_head - priv->tx_tail); + + return true; + } + + netif_start_queue(priv->ndev); + + return false; +} + +static int bxcan_chip_softreset(struct bxcan_priv *priv) +{ + struct bxcan_regs __iomem *regs = priv->regs; + u32 value; + + bxcan_rmw(priv, ®s->mcr, 0, BXCAN_MCR_RESET); + return readx_poll_timeout(readl, ®s->msr, value, + value & BXCAN_MSR_SLAK, BXCAN_TIMEOUT_US, + USEC_PER_SEC); +} + +static int bxcan_enter_init_mode(struct bxcan_priv *priv) +{ + struct bxcan_regs __iomem *regs = priv->regs; + u32 value; + + bxcan_rmw(priv, ®s->mcr, 0, BXCAN_MCR_INRQ); + return readx_poll_timeout(readl, ®s->msr, value, + value & BXCAN_MSR_INAK, BXCAN_TIMEOUT_US, + USEC_PER_SEC); +} + +static int bxcan_leave_init_mode(struct bxcan_priv *priv) +{ + struct bxcan_regs __iomem *regs = priv->regs; + u32 value; + + bxcan_rmw(priv, ®s->mcr, BXCAN_MCR_INRQ, 0); + return readx_poll_timeout(readl, ®s->msr, value, + !(value & BXCAN_MSR_INAK), BXCAN_TIMEOUT_US, + USEC_PER_SEC); +} + +static int bxcan_enter_sleep_mode(struct bxcan_priv *priv) +{ + struct bxcan_regs __iomem *regs = priv->regs; + u32 value; + + bxcan_rmw(priv, ®s->mcr, 0, BXCAN_MCR_SLEEP); + return readx_poll_timeout(readl, ®s->msr, value, + value & BXCAN_MSR_SLAK, BXCAN_TIMEOUT_US, + USEC_PER_SEC); +} + +static int bxcan_leave_sleep_mode(struct bxcan_priv *priv) +{ + struct bxcan_regs __iomem *regs = priv->regs; + u32 value; + + bxcan_rmw(priv, ®s->mcr, BXCAN_MCR_SLEEP, 0); + return readx_poll_timeout(readl, ®s->msr, value, + !(value & BXCAN_MSR_SLAK), BXCAN_TIMEOUT_US, + USEC_PER_SEC); +} + +static inline +struct bxcan_priv *rx_offload_to_priv(struct can_rx_offload *offload) +{ + return container_of(offload, struct bxcan_priv, offload); +} + +static struct sk_buff *bxcan_mailbox_read(struct can_rx_offload *offload, + unsigned int mbxno, u32 *timestamp, + bool drop) +{ + struct bxcan_priv *priv = rx_offload_to_priv(offload); + struct bxcan_regs __iomem *regs = priv->regs; + struct bxcan_mb __iomem *mb_regs = ®s->rx_mb[0]; + struct sk_buff *skb = NULL; + struct can_frame *cf; + u32 rf0r, id, dlc; + + rf0r = readl(®s->rf0r); + if (unlikely(drop)) { + skb = ERR_PTR(-ENOBUFS); + goto mark_as_read; + } + + if (!(rf0r & BXCAN_RF0R_FMP0_MASK)) + goto mark_as_read; + + skb = alloc_can_skb(offload->dev, &cf); + if (unlikely(!skb)) { + skb = ERR_PTR(-ENOMEM); + goto mark_as_read; + } + + id = readl(&mb_regs->id); + if (id & BXCAN_RIxR_IDE) + cf->can_id = FIELD_GET(BXCAN_RIxR_EXID_MASK, id) | CAN_EFF_FLAG; + else + cf->can_id = FIELD_GET(BXCAN_RIxR_STID_MASK, id) & CAN_SFF_MASK; + + dlc = readl(&mb_regs->dlc); + priv->timestamp = FIELD_GET(BXCAN_RDTxR_TIME_MASK, dlc); + cf->len = can_cc_dlc2len(FIELD_GET(BXCAN_RDTxR_DLC_MASK, dlc)); + + if (id & BXCAN_RIxR_RTR) { + cf->can_id |= CAN_RTR_FLAG; + } else { + int i, j; + + for (i = 0, j = 0; i < cf->len; i += 4, j++) + *(u32 *)(cf->data + i) = readl(&mb_regs->data[j]); + } + + mark_as_read: + rf0r |= BXCAN_RF0R_RFOM0; + writel(rf0r, ®s->rf0r); + return skb; +} + +static irqreturn_t bxcan_rx_isr(int irq, void *dev_id) +{ + struct net_device *ndev = dev_id; + struct bxcan_priv *priv = netdev_priv(ndev); + + can_rx_offload_irq_offload_fifo(&priv->offload); + can_rx_offload_irq_finish(&priv->offload); + + return IRQ_HANDLED; +} + +static irqreturn_t bxcan_tx_isr(int irq, void *dev_id) +{ + struct net_device *ndev = dev_id; + struct bxcan_priv *priv = netdev_priv(ndev); + struct bxcan_regs __iomem *regs = priv->regs; + struct net_device_stats *stats = &ndev->stats; + u32 tsr, rqcp_bit; + int idx; + + tsr = readl(®s->tsr); + if (!(tsr & (BXCAN_TSR_RQCP0 | BXCAN_TSR_RQCP1 | BXCAN_TSR_RQCP2))) + return IRQ_HANDLED; + + while (priv->tx_head - priv->tx_tail > 0) { + idx = bxcan_get_tx_tail(priv); + rqcp_bit = BXCAN_TSR_RQCP0 << (idx << 3); + if (!(tsr & rqcp_bit)) + break; + + stats->tx_packets++; + stats->tx_bytes += can_get_echo_skb(ndev, idx, NULL); + priv->tx_tail++; + } + + writel(tsr, ®s->tsr); + + if (bxcan_get_tx_free(priv)) { + /* Make sure that anybody stopping the queue after + * this sees the new tx_ring->tail. + */ + smp_mb(); + netif_wake_queue(ndev); + } + + return IRQ_HANDLED; +} + +static void bxcan_handle_state_change(struct net_device *ndev, u32 esr) +{ + struct bxcan_priv *priv = netdev_priv(ndev); + enum can_state new_state = priv->can.state; + struct can_berr_counter bec; + enum can_state rx_state, tx_state; + struct sk_buff *skb; + struct can_frame *cf; + + /* Early exit if no error flag is set */ + if (!(esr & (BXCAN_ESR_EWGF | BXCAN_ESR_EPVF | BXCAN_ESR_BOFF))) + return; + + bec.txerr = FIELD_GET(BXCAN_ESR_TEC_MASK, esr); + bec.rxerr = FIELD_GET(BXCAN_ESR_REC_MASK, esr); + + if (esr & BXCAN_ESR_BOFF) + new_state = CAN_STATE_BUS_OFF; + else if (esr & BXCAN_ESR_EPVF) + new_state = CAN_STATE_ERROR_PASSIVE; + else if (esr & BXCAN_ESR_EWGF) + new_state = CAN_STATE_ERROR_WARNING; + + /* state hasn't changed */ + if (unlikely(new_state == priv->can.state)) + return; + + skb = alloc_can_err_skb(ndev, &cf); + + tx_state = bec.txerr >= bec.rxerr ? new_state : 0; + rx_state = bec.txerr <= bec.rxerr ? new_state : 0; + can_change_state(ndev, cf, tx_state, rx_state); + + if (new_state == CAN_STATE_BUS_OFF) { + can_bus_off(ndev); + } else if (skb) { + cf->data[6] = bec.txerr; + cf->data[7] = bec.rxerr; + } + + if (skb) { + int err; + + err = can_rx_offload_queue_timestamp(&priv->offload, skb, + priv->timestamp); + if (err) + ndev->stats.rx_fifo_errors++; + } +} + +static void bxcan_handle_bus_err(struct net_device *ndev, u32 esr) +{ + struct bxcan_priv *priv = netdev_priv(ndev); + enum bxcan_lec_code lec_code; + struct can_frame *cf; + struct sk_buff *skb; + + lec_code = FIELD_GET(BXCAN_ESR_LEC_MASK, esr); + + /* Early exit if no lec update or no error. + * No lec update means that no CAN bus event has been detected + * since CPU wrote BXCAN_LEC_UNUSED value to status reg. + */ + if (lec_code == BXCAN_LEC_UNUSED || lec_code == BXCAN_LEC_NO_ERROR) + return; + + /* Common for all type of bus errors */ + priv->can.can_stats.bus_error++; + + /* Propagate the error condition to the CAN stack */ + skb = alloc_can_err_skb(ndev, &cf); + if (skb) + cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; + + switch (lec_code) { + case BXCAN_LEC_STUFF_ERROR: + netdev_dbg(ndev, "Stuff error\n"); + ndev->stats.rx_errors++; + if (skb) + cf->data[2] |= CAN_ERR_PROT_STUFF; + + break; + case BXCAN_LEC_FORM_ERROR: + netdev_dbg(ndev, "Form error\n"); + ndev->stats.rx_errors++; + if (skb) + cf->data[2] |= CAN_ERR_PROT_FORM; + + break; + case BXCAN_LEC_ACK_ERROR: + netdev_dbg(ndev, "Ack error\n"); + ndev->stats.tx_errors++; + if (skb) { + cf->can_id |= CAN_ERR_ACK; + cf->data[3] = CAN_ERR_PROT_LOC_ACK; + } + + break; + case BXCAN_LEC_BIT1_ERROR: + netdev_dbg(ndev, "Bit error (recessive)\n"); + ndev->stats.tx_errors++; + if (skb) + cf->data[2] |= CAN_ERR_PROT_BIT1; + + break; + case BXCAN_LEC_BIT0_ERROR: + netdev_dbg(ndev, "Bit error (dominant)\n"); + ndev->stats.tx_errors++; + if (skb) + cf->data[2] |= CAN_ERR_PROT_BIT0; + + break; + case BXCAN_LEC_CRC_ERROR: + netdev_dbg(ndev, "CRC error\n"); + ndev->stats.rx_errors++; + if (skb) { + cf->data[2] |= CAN_ERR_PROT_BIT; + cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ; + } + + break; + default: + break; + } + + if (skb) { + int err; + + err = can_rx_offload_queue_timestamp(&priv->offload, skb, + priv->timestamp); + if (err) + ndev->stats.rx_fifo_errors++; + } +} + +static irqreturn_t bxcan_state_change_isr(int irq, void *dev_id) +{ + struct net_device *ndev = dev_id; + struct bxcan_priv *priv = netdev_priv(ndev); + struct bxcan_regs __iomem *regs = priv->regs; + u32 msr, esr; + + msr = readl(®s->msr); + if (!(msr & BXCAN_MSR_ERRI)) + return IRQ_NONE; + + esr = readl(®s->esr); + bxcan_handle_state_change(ndev, esr); + + if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) + bxcan_handle_bus_err(ndev, esr); + + msr |= BXCAN_MSR_ERRI; + writel(msr, ®s->msr); + can_rx_offload_irq_finish(&priv->offload); + + return IRQ_HANDLED; +} + +static int bxcan_chip_start(struct net_device *ndev) +{ + struct bxcan_priv *priv = netdev_priv(ndev); + struct bxcan_regs __iomem *regs = priv->regs; + struct can_bittiming *bt = &priv->can.bittiming; + u32 clr, set; + int err; + + err = bxcan_chip_softreset(priv); + if (err) { + netdev_err(ndev, "failed to reset chip, error %d\n", err); + return err; + } + + err = bxcan_leave_sleep_mode(priv); + if (err) { + netdev_err(ndev, "failed to leave sleep mode, error %d\n", err); + goto failed_leave_sleep; + } + + err = bxcan_enter_init_mode(priv); + if (err) { + netdev_err(ndev, "failed to enter init mode, error %d\n", err); + goto failed_enter_init; + } + + /* MCR + * + * select request order priority + * enable time triggered mode + * bus-off state left on sw request + * sleep mode left on sw request + * retransmit automatically on error + * do not lock RX FIFO on overrun + */ + bxcan_rmw(priv, ®s->mcr, + BXCAN_MCR_ABOM | BXCAN_MCR_AWUM | BXCAN_MCR_NART | + BXCAN_MCR_RFLM, BXCAN_MCR_TTCM | BXCAN_MCR_TXFP); + + /* Bit timing register settings */ + set = FIELD_PREP(BXCAN_BTR_BRP_MASK, bt->brp - 1) | + FIELD_PREP(BXCAN_BTR_TS1_MASK, bt->phase_seg1 + + bt->prop_seg - 1) | + FIELD_PREP(BXCAN_BTR_TS2_MASK, bt->phase_seg2 - 1) | + FIELD_PREP(BXCAN_BTR_SJW_MASK, bt->sjw - 1); + + /* loopback + silent mode put the controller in test mode, + * useful for hot self-test + */ + if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) + set |= BXCAN_BTR_LBKM; + + if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) + set |= BXCAN_BTR_SILM; + + netdev_dbg(ndev, + "TQ[ns]: %d, PrS: %d, PhS1: %d, PhS2: %d, SJW: %d, BRP: %d, CAN_BTR: 0x%08x\n", + bt->tq, bt->prop_seg, bt->phase_seg1, bt->phase_seg2, + bt->sjw, bt->brp, set); + bxcan_rmw(priv, ®s->btr, BXCAN_BTR_SILM | BXCAN_BTR_LBKM | + BXCAN_BTR_BRP_MASK | BXCAN_BTR_TS1_MASK | BXCAN_BTR_TS2_MASK | + BXCAN_BTR_SJW_MASK, set); + + bxcan_enable_filters(priv, priv->master); + + /* Clear all internal status */ + priv->tx_head = 0; + priv->tx_tail = 0; + + err = bxcan_leave_init_mode(priv); + if (err) { + netdev_err(ndev, "failed to leave init mode, error %d\n", err); + goto failed_leave_init; + } + + /* Set a `lec` value so that we can check for updates later */ + bxcan_rmw(priv, ®s->esr, BXCAN_ESR_LEC_MASK, + FIELD_PREP(BXCAN_ESR_LEC_MASK, BXCAN_LEC_UNUSED)); + + /* IER + * + * Enable interrupt for: + * bus-off + * passive error + * warning error + * last error code + * RX FIFO pending message + * TX mailbox empty + */ + clr = BXCAN_IER_WKUIE | BXCAN_IER_SLKIE | BXCAN_IER_FOVIE1 | + BXCAN_IER_FFIE1 | BXCAN_IER_FMPIE1 | BXCAN_IER_FOVIE0 | + BXCAN_IER_FFIE0; + set = BXCAN_IER_ERRIE | BXCAN_IER_BOFIE | BXCAN_IER_EPVIE | + BXCAN_IER_EWGIE | BXCAN_IER_FMPIE0 | BXCAN_IER_TMEIE; + + if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) + set |= BXCAN_IER_LECIE; + else + clr |= BXCAN_IER_LECIE; + + bxcan_rmw(priv, ®s->ier, clr, set); + + priv->can.state = CAN_STATE_ERROR_ACTIVE; + return 0; + +failed_leave_init: +failed_enter_init: +failed_leave_sleep: + bxcan_chip_softreset(priv); + return err; +} + +static int bxcan_open(struct net_device *ndev) +{ + struct bxcan_priv *priv = netdev_priv(ndev); + int err; + + err = open_candev(ndev); + if (err) { + netdev_err(ndev, "open_candev() failed, error %d\n", err); + return err; + } + + can_rx_offload_enable(&priv->offload); + err = request_irq(ndev->irq, bxcan_rx_isr, IRQF_SHARED, ndev->name, + ndev); + if (err) { + netdev_err(ndev, "failed to register rx irq(%d), error %d\n", + ndev->irq, err); + goto out_close_candev; + } + + err = request_irq(priv->tx_irq, bxcan_tx_isr, IRQF_SHARED, ndev->name, + ndev); + if (err) { + netdev_err(ndev, "failed to register tx irq(%d), error %d\n", + priv->tx_irq, err); + goto out_free_rx_irq; + } + + err = request_irq(priv->sce_irq, bxcan_state_change_isr, IRQF_SHARED, + ndev->name, ndev); + if (err) { + netdev_err(ndev, "failed to register sce irq(%d), error %d\n", + priv->sce_irq, err); + goto out_free_tx_irq; + } + + err = bxcan_chip_start(ndev); + if (err) + goto out_free_sce_irq; + + netif_start_queue(ndev); + return 0; + +out_free_sce_irq: + free_irq(priv->sce_irq, ndev); +out_free_tx_irq: + free_irq(priv->tx_irq, ndev); +out_free_rx_irq: + free_irq(ndev->irq, ndev); +out_close_candev: + can_rx_offload_disable(&priv->offload); + close_candev(ndev); + return err; +} + +static void bxcan_chip_stop(struct net_device *ndev) +{ + struct bxcan_priv *priv = netdev_priv(ndev); + struct bxcan_regs __iomem *regs = priv->regs; + + /* disable all interrupts */ + bxcan_rmw(priv, ®s->ier, BXCAN_IER_SLKIE | BXCAN_IER_WKUIE | + BXCAN_IER_ERRIE | BXCAN_IER_LECIE | BXCAN_IER_BOFIE | + BXCAN_IER_EPVIE | BXCAN_IER_EWGIE | BXCAN_IER_FOVIE1 | + BXCAN_IER_FFIE1 | BXCAN_IER_FMPIE1 | BXCAN_IER_FOVIE0 | + BXCAN_IER_FFIE0 | BXCAN_IER_FMPIE0 | BXCAN_IER_TMEIE, 0); + bxcan_disable_filters(priv, priv->master); + bxcan_enter_sleep_mode(priv); + priv->can.state = CAN_STATE_STOPPED; +} + +static int bxcan_stop(struct net_device *ndev) +{ + struct bxcan_priv *priv = netdev_priv(ndev); + + netif_stop_queue(ndev); + bxcan_chip_stop(ndev); + free_irq(ndev->irq, ndev); + free_irq(priv->tx_irq, ndev); + free_irq(priv->sce_irq, ndev); + can_rx_offload_disable(&priv->offload); + close_candev(ndev); + return 0; +} + +static netdev_tx_t bxcan_start_xmit(struct sk_buff *skb, + struct net_device *ndev) +{ + struct bxcan_priv *priv = netdev_priv(ndev); + struct can_frame *cf = (struct can_frame *)skb->data; + struct bxcan_regs __iomem *regs = priv->regs; + struct bxcan_mb __iomem *mb_regs; + unsigned int idx; + u32 id; + int i, j; + + if (can_dropped_invalid_skb(ndev, skb)) + return NETDEV_TX_OK; + + if (bxcan_tx_busy(priv)) + return NETDEV_TX_BUSY; + + idx = bxcan_get_tx_head(priv); + priv->tx_head++; + if (bxcan_get_tx_free(priv) == 0) + netif_stop_queue(ndev); + + mb_regs = ®s->tx_mb[idx]; + if (cf->can_id & CAN_EFF_FLAG) + id = FIELD_PREP(BXCAN_TIxR_EXID_MASK, cf->can_id) | + BXCAN_TIxR_IDE; + else + id = FIELD_PREP(BXCAN_TIxR_STID_MASK, cf->can_id); + + if (cf->can_id & CAN_RTR_FLAG) + id |= BXCAN_TIxR_RTR; + + writel(FIELD_PREP(BXCAN_TDTxR_DLC_MASK, cf->len), &mb_regs->dlc); + + for (i = 0, j = 0; i < cf->len; i += 4, j++) + writel(*(u32 *)(cf->data + i), &mb_regs->data[j]); + + can_put_echo_skb(skb, ndev, idx, 0); + + /* Start transmission */ + writel(id | BXCAN_TIxR_TXRQ, &mb_regs->id); + + return NETDEV_TX_OK; +} + +static const struct net_device_ops bxcan_netdev_ops = { + .ndo_open = bxcan_open, + .ndo_stop = bxcan_stop, + .ndo_start_xmit = bxcan_start_xmit, + .ndo_change_mtu = can_change_mtu, +}; + +static int bxcan_do_set_mode(struct net_device *ndev, enum can_mode mode) +{ + int err; + + switch (mode) { + case CAN_MODE_START: + err = bxcan_chip_start(ndev); + if (err) + return err; + + netif_wake_queue(ndev); + break; + default: + return -EOPNOTSUPP; + } + + return 0; +} + +static int bxcan_get_berr_counter(const struct net_device *ndev, + struct can_berr_counter *bec) +{ + struct bxcan_priv *priv = netdev_priv(ndev); + struct bxcan_regs __iomem *regs = priv->regs; + u32 esr; + int err; + + err = clk_prepare_enable(priv->clk); + if (err) + return err; + + esr = readl(®s->esr); + bec->txerr = FIELD_GET(BXCAN_ESR_TEC_MASK, esr); + bec->rxerr = FIELD_GET(BXCAN_ESR_REC_MASK, esr); + clk_disable_unprepare(priv->clk); + return 0; +} + +static int bxcan_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct device *dev = &pdev->dev; + struct net_device *ndev; + struct bxcan_priv *priv; + struct clk *clk = NULL; + void __iomem *regs; + struct regmap *gcan; + bool master; + int err, rx_irq, tx_irq, sce_irq; + + regs = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(regs)) { + dev_err(dev, "failed to get base address\n"); + return PTR_ERR(regs); + } + + gcan = syscon_regmap_lookup_by_phandle(np, "st,gcan"); + if (IS_ERR(gcan)) { + dev_err(dev, "failed to get shared memory base address\n"); + return PTR_ERR(gcan); + } + + master = of_property_read_bool(np, "st,can-master"); + clk = devm_clk_get(dev, NULL); + if (IS_ERR(clk)) { + dev_err(dev, "failed to get clock\n"); + return PTR_ERR(clk); + } + + rx_irq = platform_get_irq_byname(pdev, "rx0"); + if (rx_irq < 0) { + dev_err(dev, "failed to get rx0 irq\n"); + return rx_irq; + } + + tx_irq = platform_get_irq_byname(pdev, "tx"); + if (tx_irq < 0) { + dev_err(dev, "failed to get tx irq\n"); + return tx_irq; + } + + sce_irq = platform_get_irq_byname(pdev, "sce"); + if (sce_irq < 0) { + dev_err(dev, "failed to get sce irq\n"); + return sce_irq; + } + + ndev = alloc_candev(sizeof(struct bxcan_priv), BXCAN_TX_MB_NUM); + if (!ndev) { + dev_err(dev, "alloc_candev() failed\n"); + return -ENOMEM; + } + + priv = netdev_priv(ndev); + platform_set_drvdata(pdev, ndev); + SET_NETDEV_DEV(ndev, dev); + ndev->netdev_ops = &bxcan_netdev_ops; + ndev->irq = rx_irq; + ndev->flags |= IFF_ECHO; + + priv->dev = dev; + priv->ndev = ndev; + priv->regs = regs; + priv->gcan = gcan; + priv->clk = clk; + priv->tx_irq = tx_irq; + priv->sce_irq = sce_irq; + priv->master = master; + priv->can.clock.freq = clk_get_rate(clk); + spin_lock_init(&priv->rmw_lock); + priv->tx_head = 0; + priv->tx_tail = 0; + priv->can.bittiming_const = &bxcan_bittiming_const; + priv->can.do_set_mode = bxcan_do_set_mode; + priv->can.do_get_berr_counter = bxcan_get_berr_counter; + priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK | + CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_BERR_REPORTING; + + priv->offload.mailbox_read = bxcan_mailbox_read; + err = can_rx_offload_add_fifo(ndev, &priv->offload, BXCAN_NAPI_WEIGHT); + if (err) { + dev_err(dev, "failed to add FIFO rx_offload\n"); + goto out_free_candev; + } + + err = clk_prepare_enable(priv->clk); + if (err) { + dev_err(dev, "failed to enable clock\n"); + goto out_can_rx_offload_del; + } + + err = register_candev(ndev); + if (err) { + dev_err(dev, "failed to register netdev\n"); + goto out_clk_disable_unprepare; + } + + dev_info(dev, "clk: %d Hz, IRQs: %d, %d, %d\n", priv->can.clock.freq, + tx_irq, rx_irq, sce_irq); + return 0; + +out_clk_disable_unprepare: + clk_disable_unprepare(priv->clk); +out_can_rx_offload_del: + can_rx_offload_del(&priv->offload); +out_free_candev: + free_candev(ndev); + return err; +} + +static int bxcan_remove(struct platform_device *pdev) +{ + struct net_device *ndev = platform_get_drvdata(pdev); + struct bxcan_priv *priv = netdev_priv(ndev); + + unregister_candev(ndev); + clk_disable_unprepare(priv->clk); + can_rx_offload_del(&priv->offload); + free_candev(ndev); + return 0; +} + +static int __maybe_unused bxcan_suspend(struct device *dev) +{ + struct net_device *ndev = dev_get_drvdata(dev); + struct bxcan_priv *priv = netdev_priv(ndev); + + if (!netif_running(ndev)) + return 0; + + netif_stop_queue(ndev); + netif_device_detach(ndev); + + bxcan_enter_sleep_mode(priv); + priv->can.state = CAN_STATE_SLEEPING; + clk_disable_unprepare(priv->clk); + return 0; +} + +static int __maybe_unused bxcan_resume(struct device *dev) +{ + struct net_device *ndev = dev_get_drvdata(dev); + struct bxcan_priv *priv = netdev_priv(ndev); + + if (!netif_running(ndev)) + return 0; + + clk_prepare_enable(priv->clk); + bxcan_leave_sleep_mode(priv); + priv->can.state = CAN_STATE_ERROR_ACTIVE; + + netif_device_attach(ndev); + netif_start_queue(ndev); + return 0; +} + +static SIMPLE_DEV_PM_OPS(bxcan_pm_ops, bxcan_suspend, bxcan_resume); + +static const struct of_device_id bxcan_of_match[] = { + {.compatible = "st,stm32f4-bxcan"}, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(of, bxcan_of_match); + +static struct platform_driver bxcan_driver = { + .driver = { + .name = KBUILD_MODNAME, + .pm = &bxcan_pm_ops, + .of_match_table = bxcan_of_match, + }, + .probe = bxcan_probe, + .remove = bxcan_remove, +}; + +module_platform_driver(bxcan_driver); + +MODULE_AUTHOR("Dario Binacchi "); +MODULE_DESCRIPTION("STMicroelectronics Basic Extended CAN controller driver"); +MODULE_LICENSE("GPL");