[U-Boot] [PATCH v2 4/4] pinctrl: stm32: make pinctrl use hwspinlock

[Simon Glass]

On 14 November 2018 at 01:01, Benjamin Gaignard
<benjamin.gaignard at linaro.org> wrote:
> From: Benjamin Gaignard <benjamin.gaignard at linaro.org>
>
> Protect configuration registers with a hardware spinlock.
>
> If a hwspinlock is defined in the device-tree node used it
> to be sure that none of the others processors on the SoC could
> change the configuration at the same time.
>
> Signed-off-by: Benjamin Gaignard <benjamin.gaignard at linaro.org>
> ---
> version 2:
> - be more verbose in commit message
> - log the error after hwspinlock_get_by_index()
>
>  arch/arm/dts/stm32mp157c-ed1.dts |  4 ++++
>  drivers/pinctrl/pinctrl_stm32.c  | 27 +++++++++++++++++++++++++++
>  2 files changed, 31 insertions(+)

Reviewed-by: Simon Glass <sjg at chromium.org>

with nit below

>
> diff --git a/arch/arm/dts/stm32mp157c-ed1.dts b/arch/arm/dts/stm32mp157c-ed1.dts
> index fc277dd7d2..7a9b742d36 100644
> --- a/arch/arm/dts/stm32mp157c-ed1.dts
> +++ b/arch/arm/dts/stm32mp157c-ed1.dts
> @@ -369,6 +369,10 @@
>         status = "okay";
>  };
>
> +&pinctrl {
> +       hwlocks = <&hwspinlock 0>;
> +};
> +
>  &usbphyc_port0 {
>         phy-supply = <&vdd_usb>;
>         vdda1v1-supply = <&reg11>;
> diff --git a/drivers/pinctrl/pinctrl_stm32.c b/drivers/pinctrl/pinctrl_stm32.c
> index 31285cdd57..5b63a2de15 100644
> --- a/drivers/pinctrl/pinctrl_stm32.c
> +++ b/drivers/pinctrl/pinctrl_stm32.c
> @@ -1,6 +1,7 @@
>  #include <common.h>
>  #include <dm.h>
>  #include <dm/pinctrl.h>
> +#include <hwspinlock.h>
>  #include <asm/arch/gpio.h>
>  #include <asm/gpio.h>
>  #include <asm/io.h>
> @@ -19,12 +20,20 @@ static int stm32_gpio_config(struct gpio_desc *desc,
>  {
>         struct stm32_gpio_priv *priv = dev_get_priv(desc->dev);
>         struct stm32_gpio_regs *regs = priv->regs;
> +       struct hwspinlock *hws = dev_get_priv(desc->dev->parent);

dev_get_parent()

>         u32 index;
> +       int ret;
>
>         if (!ctl || ctl->af > 15 || ctl->mode > 3 || ctl->otype > 1 ||
>             ctl->pupd > 2 || ctl->speed > 3)
>                 return -EINVAL;
>
> +       ret = hwspinlock_lock_timeout(hws, 1);
> +       if (ret == -ETIME) {
> +               dev_err(desc->dev, "HWSpinlock timeout\n");
> +               return ret;
> +       }
> +
>         index = (desc->offset & 0x07) * 4;
>         clrsetbits_le32(&regs->afr[desc->offset >> 3], AFR_MASK << index,
>                         ctl->af << index);
> @@ -39,6 +48,8 @@ static int stm32_gpio_config(struct gpio_desc *desc,
>         index = desc->offset;
>         clrsetbits_le32(&regs->otyper, OTYPE_MSK << index, ctl->otype << index);
>
> +       hwspinlock_unlock(hws);
> +
>         return 0;
>  }
>
> @@ -176,6 +187,20 @@ static int stm32_pinctrl_set_state_simple(struct udevice *dev,
>  }
>  #endif /* PINCTRL_FULL */
>
> +static int stm32_pinctrl_probe(struct udevice *dev)
> +{
> +       struct hwspinlock *hws = dev_get_priv(dev);
> +       int err;
> +
> +       /* hwspinlock property is optional, just log the error */
> +       err = hwspinlock_get_by_index(dev, 0, hws);
> +       if (err)
> +               debug("%s: hwspinlock_get_by_index may have failed (%d)\n",
> +                     __func__, err);
> +
> +       return 0;
> +}
> +
>  static struct pinctrl_ops stm32_pinctrl_ops = {
>  #if CONFIG_IS_ENABLED(PINCTRL_FULL)
>         .set_state              = stm32_pinctrl_set_state,
> @@ -200,4 +225,6 @@ U_BOOT_DRIVER(pinctrl_stm32) = {
>         .of_match       = stm32_pinctrl_ids,
>         .ops            = &stm32_pinctrl_ops,
>         .bind           = dm_scan_fdt_dev,
> +       .probe          = stm32_pinctrl_probe,
> +       .priv_auto_alloc_size = sizeof(struct hwspinlock),
>  };
> --
> 2.15.0
>