[RFC,0/4] can: bxcan: add support for ST bxCAN controller
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Message ID 20220817143529.257908-1-dario.binacchi@amarulasolutions.com
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Dario Binacchi Aug. 17, 2022, 2:35 p.m. UTC 
The series adds support for the basic extended CAN controller (bxCAN)
found in many low- to middle-end STM32 SoCs.

The driver has been tested on the stm32f469i-discovery board with a
kernel version 5.19.0-rc2 in loopback + silent mode:

ip link set can0 type can bitrate 125000 loopback on listen-only on
ip link set up can0
candump can0 -L &
cansend can0 300#AC.AB.AD.AE.75.49.AD.D1

For uboot and kernel compilation, as well as for rootfs creation I used
buildroot:

make stm32f469_disco_sd_defconfig
make

but I had to patch can-utils and busybox as can-utils and iproute are
not compiled for MMU-less microcotrollers. In the case of can-utils,
replacing the calls to fork() with vfork(), I was able to compile the
package with working candump and cansend applications, while in the
case of iproute, I ran into more than one problem and finally I decided
to extend busybox's ip link command for CAN-type devices. I'm still
wondering if it was really necessary, but this way I was able to test
the driver.


Dario Binacchi (4):
  dt-bindings: net: can: add STM32 bxcan DT bindings
  ARM: dts: stm32: add CAN support on stm32f429
  ARM: dts: stm32: add pin map for CAN controller on stm32f4
  can: bxcan: add support for ST bxCAN controller

 .../devicetree/bindings/net/can/st,bxcan.yaml | 139 +++
 arch/arm/boot/dts/stm32f4-pinctrl.dtsi        |  32 +
 arch/arm/boot/dts/stm32f429.dtsi              |  30 +
 drivers/net/can/Kconfig                       |   1 +
 drivers/net/can/Makefile                      |   1 +
 drivers/net/can/bxcan/Kconfig                 |  34 +
 drivers/net/can/bxcan/Makefile                |   4 +
 drivers/net/can/bxcan/bxcan-core.c            | 201 ++++
 drivers/net/can/bxcan/bxcan-core.h            |  33 +
 drivers/net/can/bxcan/bxcan-drv.c             | 980 ++++++++++++++++++
 10 files changed, 1455 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/can/st,bxcan.yaml
 create mode 100644 drivers/net/can/bxcan/Kconfig
 create mode 100644 drivers/net/can/bxcan/Makefile
 create mode 100644 drivers/net/can/bxcan/bxcan-core.c
 create mode 100644 drivers/net/can/bxcan/bxcan-core.h
 create mode 100644 drivers/net/can/bxcan/bxcan-drv.c

Comments

Marc Kleine-Budde Aug. 17, 2022, 9:16 p.m. UTC | #1 
I've stripped down the Cc list a bit...

On 17.08.2022 16:35:25, Dario Binacchi wrote:
> The series adds support for the basic extended CAN controller (bxCAN)
> found in many low- to middle-end STM32 SoCs.
>
> The driver has been tested on the stm32f469i-discovery board with a
> kernel version 5.19.0-rc2 in loopback + silent mode:

I've had no time for a in depth review, but here are some warnings by
the standard checker tools:

Please fix these sparse errors:

| drivers/net/can/bxcan/bxcan-drv.c:641:39: warning: incorrect type in initializer (different address spaces)
| drivers/net/can/bxcan/bxcan-drv.c:641:39:    expected struct bxcan_regs *regs
| drivers/net/can/bxcan/bxcan-drv.c:641:39:    got struct bxcan_regs [noderef] __iomem *regs
| drivers/net/can/bxcan/bxcan-drv.c:650:15: warning: incorrect type in argument 1 (different address spaces)
| drivers/net/can/bxcan/bxcan-drv.c:650:15:    expected void const volatile [noderef] __iomem *addr
| drivers/net/can/bxcan/bxcan-drv.c:650:15:    got unsigned int *
| drivers/net/can/bxcan/bxcan-drv.c:667:20: warning: incorrect type in argument 1 (different address spaces)
| drivers/net/can/bxcan/bxcan-drv.c:667:20:    expected void volatile [noderef] __iomem *addr
| drivers/net/can/bxcan/bxcan-drv.c:667:20:    got unsigned int *
| drivers/net/can/bxcan/bxcan-drv.c:672:17: warning: incorrect type in argument 2 (different address spaces)
| drivers/net/can/bxcan/bxcan-drv.c:672:17:    expected void volatile [noderef] __iomem *addr
| drivers/net/can/bxcan/bxcan-drv.c:672:17:    got unsigned int *
| drivers/net/can/bxcan/bxcan-drv.c:675:9: warning: incorrect type in argument 2 (different address spaces)
| drivers/net/can/bxcan/bxcan-drv.c:675:9:    expected void volatile [noderef] __iomem *addr
| drivers/net/can/bxcan/bxcan-drv.c:675:9:    got unsigned int *
| drivers/net/can/bxcan/bxcan-drv.c:677:15: warning: incorrect type in argument 1 (different address spaces)
| drivers/net/can/bxcan/bxcan-drv.c:677:15:    expected void const volatile [noderef] __iomem *addr
| drivers/net/can/bxcan/bxcan-drv.c:677:15:    got unsigned int *
| drivers/net/can/bxcan/bxcan-drv.c:703:14: warning: incorrect type in argument 1 (different address spaces)
| drivers/net/can/bxcan/bxcan-drv.c:703:14:    expected void const volatile [noderef] __iomem *addr
| drivers/net/can/bxcan/bxcan-drv.c:703:14:    got unsigned int *
| drivers/net/can/bxcan/bxcan-drv.c:709:15: warning: incorrect type in argument 1 (different address spaces)
| drivers/net/can/bxcan/bxcan-drv.c:709:15:    expected void const volatile [noderef] __iomem *addr
| drivers/net/can/bxcan/bxcan-drv.c:709:15:    got unsigned int *
| drivers/net/can/bxcan/bxcan-drv.c:718:50: warning: incorrect type in argument 1 (different address spaces)
| drivers/net/can/bxcan/bxcan-drv.c:718:50:    expected void const volatile [noderef] __iomem *addr
| drivers/net/can/bxcan/bxcan-drv.c:718:50:    got unsigned int *
| drivers/net/can/bxcan/bxcan-drv.c:730:39: warning: incorrect type in initializer (different address spaces)
| drivers/net/can/bxcan/bxcan-drv.c:730:39:    expected struct bxcan_regs *regs
| drivers/net/can/bxcan/bxcan-drv.c:730:39:    got struct bxcan_regs [noderef] __iomem *regs
| drivers/net/can/bxcan/bxcan-drv.c:735:24: warning: incorrect type in argument 1 (different address spaces)
| drivers/net/can/bxcan/bxcan-drv.c:735:24:    expected void const volatile [noderef] __iomem *addr
| drivers/net/can/bxcan/bxcan-drv.c:735:24:    got unsigned int *
| drivers/net/can/bxcan/bxcan-drv.c:742:17: warning: incorrect type in argument 2 (different address spaces)
| drivers/net/can/bxcan/bxcan-drv.c:742:17:    expected void volatile [noderef] __iomem *addr
| drivers/net/can/bxcan/bxcan-drv.c:742:17:    got unsigned int *
| drivers/net/can/bxcan/bxcan-drv.c:747:28: warning: incorrect type in argument 1 (different address spaces)
| drivers/net/can/bxcan/bxcan-drv.c:747:28:    expected void volatile [noderef] __iomem *addr
| drivers/net/can/bxcan/bxcan-drv.c:747:28:    got unsigned int *
| drivers/net/can/bxcan/bxcan-drv.c:802:39: warning: incorrect type in initializer (different address spaces)
| drivers/net/can/bxcan/bxcan-drv.c:802:39:    expected struct bxcan_regs *regs
| drivers/net/can/bxcan/bxcan-drv.c:802:39:    got struct bxcan_regs [noderef] __iomem *regs
| drivers/net/can/bxcan/bxcan-drv.c:810:15: warning: incorrect type in argument 1 (different address spaces)
| drivers/net/can/bxcan/bxcan-drv.c:810:15:    expected void const volatile [noderef] __iomem *addr
| drivers/net/can/bxcan/bxcan-drv.c:810:15:    got unsigned int *

(To enable sparse checking, do a "make C=1" to compile.)

Please fix these checkpatch warnings:

| WARNING: added, moved or deleted file(s), does MAINTAINERS need updating?
| #74:
| new file mode 100644

Please create a MAINTAINERS entry.

| WARNING: Using vsprintf specifier '%px' potentially exposes the kernel memory layout, if you don't really need the address please consider using '%p'.
| #307: FILE: drivers/net/can/bxcan/bxcan-core.c:179:
| +       dev_info(&pdev->dev, "regs: %px\n", priv->base);

Please remove the print of the base address.

| WARNING: Use of volatile is usually wrong: see Documentation/process/volatile-considered-harmful.rst
| #356: FILE: drivers/net/can/bxcan/bxcan-core.h:21:
| +static inline void bxcan_rmw(volatile void __iomem *addr, u32 clear, u32 set)

remove the volatile.

| WARNING: Using vsprintf specifier '%px' potentially exposes the kernel memory layout, if you don't really need the address please consider using '%p'.
| #1273: FILE: drivers/net/can/bxcan/bxcan-drv.c:899:
| +       }
| +
| +       dev_info(dev, "regs: %px, clk: %d Hz, IRQs: %d, %d, %d\n",
| +                priv->regs, priv->can.clock.freq, tx_irq, rx_irq,
| +                sce_irq);

Remote the print of the regs.

regards,
Marc

--
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
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