pinctrl: stm32: add possibility to configure pins individually

Adds the possibility to configure a single pin through the gpiolib (i.e:
to set PULL_UP/PULL_DOWN config).
Mutex behavior is slightly changed to avoid a deadlock when pin_config_set
is called (in this case pctldev->mutex is already taken).
Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>
Link: https://lore.kernel.org/r/20200615125951.28008-3-alexandre.torgue@st.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/stm32/pinctrl-stm32.c

@@ -303,6 +303,7 @@ static const struct gpio_chip stm32_gpio_template = {
 	.direction_output	= stm32_gpio_direction_output,
 	.to_irq			= stm32_gpio_to_irq,
 	.get_direction		= stm32_gpio_get_direction,
+	.set_config		= gpiochip_generic_config,
 };
 
 static void stm32_gpio_irq_trigger(struct irq_data *d)
@@ -1052,7 +1053,7 @@ static int stm32_pconf_parse_conf(struct pinctrl_dev *pctldev,
 	struct stm32_gpio_bank *bank;
 	int offset, ret = 0;
 
-	range = pinctrl_find_gpio_range_from_pin(pctldev, pin);
+	range = pinctrl_find_gpio_range_from_pin_nolock(pctldev, pin);
 	if (!range) {
 		dev_err(pctl->dev, "No gpio range defined.\n");
 		return -EINVAL;
@@ -1110,9 +1111,11 @@ static int stm32_pconf_group_set(struct pinctrl_dev *pctldev, unsigned group,
 	int i, ret;
 
 	for (i = 0; i < num_configs; i++) {
+		mutex_lock(&pctldev->mutex);
 		ret = stm32_pconf_parse_conf(pctldev, g->pin,
 			pinconf_to_config_param(configs[i]),
 			pinconf_to_config_argument(configs[i]));
+		mutex_unlock(&pctldev->mutex);
 		if (ret < 0)
 			return ret;
 
@@ -1122,6 +1125,22 @@ static int stm32_pconf_group_set(struct pinctrl_dev *pctldev, unsigned group,
 	return 0;
 }
 
+static int stm32_pconf_set(struct pinctrl_dev *pctldev, unsigned int pin,
+			   unsigned long *configs, unsigned int num_configs)
+{
+	int i, ret;
+
+	for (i = 0; i < num_configs; i++) {
+		ret = stm32_pconf_parse_conf(pctldev, pin,
+				pinconf_to_config_param(configs[i]),
+				pinconf_to_config_argument(configs[i]));
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
 static void stm32_pconf_dbg_show(struct pinctrl_dev *pctldev,
 				 struct seq_file *s,
 				 unsigned int pin)
@@ -1187,10 +1206,10 @@ static void stm32_pconf_dbg_show(struct pinctrl_dev *pctldev,
 	}
 }
 
-
 static const struct pinconf_ops stm32_pconf_ops = {
 	.pin_config_group_get	= stm32_pconf_group_get,
 	.pin_config_group_set	= stm32_pconf_group_set,
+	.pin_config_set		= stm32_pconf_set,
 	.pin_config_dbg_show	= stm32_pconf_dbg_show,
 };