From: Benjamin Gaignard benjamin.gaignard@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@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(+)
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 = <®11>; 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); 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(®s->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(®s->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), };