From a88ca6deca4f19c95811433aa23bab7b74d182bb Mon Sep 17 00:00:00 2001 From: Fabien Dessenne Date: Tue, 10 Jun 2025 17:23:05 +0200 Subject: [PATCH] pinctrl: stm32: Handle RSVD pin configuration When a pin is assigned to a coprocessor not running Linux, the pin should be flagged in the DT as reserved and not usable by Linux. Add pin configuration RSVD (Reserved) and instrument the driver to not update the mux setting. Signed-off-by: Fabien Dessenne Signed-off-by: Antonio Borneo Link: https://lore.kernel.org/20250610152309.299438-2-antonio.borneo@foss.st.com Signed-off-by: Linus Walleij --- drivers/pinctrl/stm32/pinctrl-stm32.c | 9 +++++++++ drivers/pinctrl/stm32/pinctrl-stm32.h | 3 ++- 2 files changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/pinctrl/stm32/pinctrl-stm32.c b/drivers/pinctrl/stm32/pinctrl-stm32.c index ce2a5fee42303..f47c4e6f12b4b 100644 --- a/drivers/pinctrl/stm32/pinctrl-stm32.c +++ b/drivers/pinctrl/stm32/pinctrl-stm32.c @@ -91,6 +91,7 @@ static const char * const stm32_gpio_functions[] = { "af8", "af9", "af10", "af11", "af12", "af13", "af14", "af15", "analog", + "reserved", }; struct stm32_pinctrl_group { @@ -663,6 +664,9 @@ static bool stm32_pctrl_is_function_valid(struct stm32_pinctrl *pctl, if (pin->pin.number != pin_num) continue; + if (fnum == STM32_PIN_RSVD) + return true; + for (k = 0; k < STM32_CONFIG_NUM; k++) { if (func->num == fnum) return true; @@ -962,6 +966,11 @@ static int stm32_pmx_set_mux(struct pinctrl_dev *pctldev, return -EINVAL; } + if (function == STM32_PIN_RSVD) { + dev_dbg(pctl->dev, "Reserved pins, skipping HW update.\n"); + return 0; + } + bank = gpiochip_get_data(range->gc); pin = stm32_gpio_pin(g->pin); diff --git a/drivers/pinctrl/stm32/pinctrl-stm32.h b/drivers/pinctrl/stm32/pinctrl-stm32.h index 9e44ad8c35b35..b98a4141bf2c0 100644 --- a/drivers/pinctrl/stm32/pinctrl-stm32.h +++ b/drivers/pinctrl/stm32/pinctrl-stm32.h @@ -17,7 +17,8 @@ #define STM32_PIN_GPIO 0 #define STM32_PIN_AF(x) ((x) + 1) #define STM32_PIN_ANALOG (STM32_PIN_AF(15) + 1) -#define STM32_CONFIG_NUM (STM32_PIN_ANALOG + 1) +#define STM32_PIN_RSVD (STM32_PIN_ANALOG + 1) +#define STM32_CONFIG_NUM (STM32_PIN_RSVD + 1) /* package information */ #define STM32MP_PKG_AA BIT(0) -- 2.47.2