drivers/gpio: stm32: Enable PM_DEVICE services

Implement power mgmt hooks to support PM_DEVICE and
PM_DEVICE_RUNTIME.
In case of PM_DEVICE_RUNTIME, clock is requested for bank writes
so it is requested before configuring and released only if pin
is not configured as output.

Signed-off-by: Erwan Gouriou <[email protected]>

Author: erwango

drivers/gpio/gpio_stm32.c

@@ -22,6 +22,8 @@
 #include <drivers/pinmux.h>
 #include <sys/util.h>
 #include <drivers/interrupt_controller/exti_stm32.h>
+#include <pm/device.h>
+#include <pm/device_runtime.h>
 
 #include "stm32_hsem.h"
 #include "gpio_stm32.h"
@@ -238,7 +240,6 @@ int gpio_stm32_clock_request(const struct device *dev, bool on)
 	if (on) {
 		ret = clock_control_on(clk,
 					(clock_control_subsys_t *)&cfg->pclken);
-
 	} else {
 		ret = clock_control_off(clk,
 					(clock_control_subsys_t *)&cfg->pclken);
@@ -463,6 +464,9 @@ static int gpio_stm32_port_toggle_bits(const struct device *dev,
 static int gpio_stm32_config(const struct device *dev,
 			     gpio_pin_t pin, gpio_flags_t flags)
 {
+#ifdef CONFIG_PM_DEVICE_RUNTIME
+	struct gpio_stm32_data *data = dev->data;
+#endif /* CONFIG_PM_DEVICE_RUNTIME */
 	int err = 0;
 	int pincfg;
 
@@ -474,6 +478,16 @@ static int gpio_stm32_config(const struct device *dev,
 		goto exit;
 	}
 
+#ifdef CONFIG_PM_DEVICE_RUNTIME
+	/* Enable device clock before configuration (requires bank writes) */
+	if (data->power_state != PM_DEVICE_ACTIVE_STATE) {
+		err = pm_device_get_sync(dev);
+		if (err < 0) {
+			return err;
+		}
+	}
+#endif /* CONFIG_PM_DEVICE_RUNTIME */
+
 	if ((flags & GPIO_OUTPUT) != 0) {
 		if ((flags & GPIO_OUTPUT_INIT_HIGH) != 0) {
 			gpio_stm32_port_set_bits_raw(dev, BIT(pin));
@@ -484,6 +498,17 @@ static int gpio_stm32_config(const struct device *dev,
 
 	gpio_stm32_configure(dev, pin, pincfg, 0);
 
+	/* Device released */
+#ifdef CONFIG_PM_DEVICE_RUNTIME
+	/* Release clock only if configuration doesn't require bank writes */
+	if ((flags & GPIO_OUTPUT) == 0) {
+		err = pm_device_put(dev);
+		if (err < 0) {
+			return err;
+		}
+	}
+#endif /* CONFIG_PM_DEVICE_RUNTIME */
+
 exit:
 	return err;
 }
@@ -561,6 +586,69 @@ static const struct gpio_driver_api gpio_stm32_driver = {
 	.manage_callback = gpio_stm32_manage_callback,
 };
 
+#ifdef CONFIG_PM_DEVICE
+static uint32_t gpio_stm32_get_power_state(const struct device *dev)
+{
+	struct gpio_stm32_data *data = dev->data;
+
+	return data->power_state;
+}
+
+static int gpio_stm32_set_power_state(const struct device *dev,
+					      uint32_t new_state)
+{
+	struct gpio_stm32_data *data = dev->data;
+	int ret = 0;
+
+	if (new_state == PM_DEVICE_ACTIVE_STATE) {
+		ret = gpio_stm32_clock_request(dev, true);
+	} else if (new_state == PM_DEVICE_SUSPEND_STATE) {
+		ret = gpio_stm32_clock_request(dev, false);
+	} else if (new_state == PM_DEVICE_LOW_POWER_STATE) {
+		ret = gpio_stm32_clock_request(dev, false);
+	}
+
+	if (ret < 0) {
+		return ret;
+	}
+
+	data->power_state = new_state;
+
+	return 0;
+}
+
+static int gpio_stm32_pm_device_ctrl(const struct device *dev,
+				     uint32_t ctrl_command,
+				     void *context, pm_device_cb cb, void *arg)
+{
+	struct gpio_stm32_data *data = dev->data;
+	uint32_t new_state;
+	int ret = 0;
+
+	switch (ctrl_command) {
+	case PM_DEVICE_STATE_SET:
+		new_state = *((const uint32_t *)context);
+		if (new_state != data->power_state) {
+			ret = gpio_stm32_set_power_state(dev, new_state);
+		}
+		break;
+	case PM_DEVICE_STATE_GET:
+		*((uint32_t *)context) = gpio_stm32_get_power_state(dev);
+		break;
+	default:
+		ret = -EINVAL;
+
+	}
+
+	if (cb) {
+		cb(dev, ret, context, arg);
+	}
+
+	return ret;
+}
+#endif /* CONFIG_PM_DEVICE */
+
+
 /**
  * @brief Initialize GPIO port
  *
@@ -577,7 +665,25 @@ static int gpio_stm32_init(const struct device *dev)
 
 	data->dev = dev;
 
+#if defined(PWR_CR2_IOSV) && DT_NODE_HAS_STATUS(DT_NODELABEL(gpiog), okay)
+	z_stm32_hsem_lock(CFG_HW_RCC_SEMID, HSEM_LOCK_DEFAULT_RETRY);
+	/* Port G[15:2] requires external power supply */
+	/* Cf: L4/L5 RM, Chapter "Independent I/O supply rail" */
+	LL_PWR_EnableVddIO2();
+	z_stm32_hsem_unlock(CFG_HW_RCC_SEMID);
+#endif
+
+#ifdef CONFIG_PM_DEVICE_RUNTIME
+	data->power_state = PM_DEVICE_OFF_STATE;
+	pm_device_enable(dev);
+
+	return 0;
+#else
+#ifdef CONFIG_PM_DEVICE
+	data->power_state = PM_DEVICE_ACTIVE_STATE;
+#endif
 	return gpio_stm32_clock_request(dev, true);
+#endif
 }
 
 #define GPIO_DEVICE_INIT(__node, __suffix, __base_addr, __port, __cenr, __bus) \
@@ -592,7 +698,7 @@ static int gpio_stm32_init(const struct device *dev)
 	static struct gpio_stm32_data gpio_stm32_data_## __suffix;	       \
 	DEVICE_DT_DEFINE(__node,					       \
 			    gpio_stm32_init,				       \
-			    NULL,					       \
+			    gpio_stm32_pm_device_ctrl,			       \
 			    &gpio_stm32_data_## __suffix,		       \
 			    &gpio_stm32_cfg_## __suffix,		       \
 			    POST_KERNEL,				       \

drivers/gpio/gpio_stm32.h

@@ -229,6 +229,10 @@ struct gpio_stm32_data {
 	const struct device *dev;
 	/* user ISR cb */
 	sys_slist_t cb;
+#ifdef CONFIG_PM_DEVICE
+	/* device power state */
+	uint32_t power_state;
+#endif
 };
 
 /**