drivers: ethernet: phy: phy_mii: add gpio reset

Add support for hardware reset to the phy_mii driver

Signed-off-by: Matthias Alleman <[email protected]>

Author: allemanm

drivers/ethernet/phy/Kconfig

@@ -33,6 +33,7 @@ config PHY_GENERIC_MII
 	default y
 	depends on DT_HAS_ETHERNET_PHY_ENABLED
 	select MDIO
+	select GPIO if $(dt_compat_any_has_prop,$(DT_COMPAT_ETHERNET_PHY),reset-gpios)
 	help
 	  This is a generic MII PHY interface that communicates with the
 	  PHY using the MDIO bus.

drivers/ethernet/phy/phy_mii.c

@@ -11,6 +11,7 @@
 #include <zephyr/device.h>
 #include <zephyr/init.h>
 #include <zephyr/kernel.h>
+#include <zephyr/drivers/gpio.h>
 #include <zephyr/drivers/mdio.h>
 #include <zephyr/net/phy.h>
 #include <zephyr/net/mii.h>
@@ -22,6 +23,7 @@ LOG_MODULE_REGISTER(phy_mii, CONFIG_PHY_LOG_LEVEL);
 
 #define ANY_DYNAMIC_LINK UTIL_NOT(DT_ALL_INST_HAS_PROP_STATUS_OKAY(fixed_link))
 #define ANY_FIXED_LINK   DT_ANY_INST_HAS_PROP_STATUS_OKAY(fixed_link)
+#define ANY_RESET_GPIO   DT_ANY_INST_HAS_PROP_STATUS_OKAY(reset_gpios)
 
 struct phy_mii_dev_config {
 	uint8_t phy_addr;
@@ -30,6 +32,11 @@ struct phy_mii_dev_config {
 	int fixed_speed;
 	enum phy_link_speed default_speeds;
 	const struct device * const mdio;
+#if ANY_RESET_GPIO
+	const struct gpio_dt_spec reset_gpio;
+	uint32_t reset_assert_duration_us;
+	uint32_t reset_deassertion_timeout_ms;
+#endif /* ANY_RESET_GPIO */
 };
 
 struct phy_mii_dev_data {
@@ -120,6 +127,33 @@ static int reset(const struct device *dev)
 	uint32_t timeout = 12U;
 	uint16_t value;
 
+#if ANY_RESET_GPIO
+	const struct phy_mii_dev_config *const cfg = dev->config;
+	int ret;
+
+	if (gpio_is_ready_dt(&cfg->reset_gpio)) {
+		/* Issue a hard reset */
+		ret = gpio_pin_configure_dt(&cfg->reset_gpio, GPIO_OUTPUT_ACTIVE);
+		if (ret < 0) {
+			LOG_ERR("Failed to configure RST pin (%d)", ret);
+			return ret;
+		}
+
+		/* assertion time */
+		k_busy_wait(cfg->reset_assert_duration_us);
+
+		ret = gpio_pin_set_dt(&cfg->reset_gpio, 0);
+		if (ret < 0) {
+			LOG_ERR("Failed to de-assert RST pin (%d)", ret);
+			return ret;
+		}
+
+		k_msleep(cfg->reset_deassertion_timeout_ms);
+
+		return 0;
+	}
+#endif /* ANY_RESET_GPIO */
+
 	/* Issue a soft reset */
 	if (phy_mii_reg_write(dev, MII_BMCR, MII_BMCR_RESET) < 0) {
 		return -EIO;
@@ -547,6 +581,18 @@ static DEVICE_API(ethphy, phy_mii_driver_api) = {
 #endif
 };
 
+#if ANY_RESET_GPIO
+#define RESET_GPIO(n)							 \
+	.reset_gpio = GPIO_DT_SPEC_INST_GET_OR(n,			 \
+			 reset_gpios, {0}),				 \
+	.reset_assert_duration_us = DT_INST_PROP_OR(n,			 \
+			 reset_assert_duration_us, 0),			 \
+	.reset_deassertion_timeout_ms = DT_INST_PROP_OR(n,		 \
+			 reset_deassertion_timeout_ms, 0),
+#else
+#define RESET_GPIO(n)
+#endif /* ANY_RESET_GPIO */
+
 #define PHY_MII_CONFIG(n)						 \
 BUILD_ASSERT(PHY_INST_GENERATE_DEFAULT_SPEEDS(n) != 0,			 \
 	"At least one valid speed must be configured for this driver");	 \
@@ -558,7 +604,8 @@ static const struct phy_mii_dev_config phy_mii_dev_config_##n = {	 \
 	.fixed_speed = DT_INST_ENUM_IDX_OR(n, fixed_link, 0),		 \
 	.default_speeds = PHY_INST_GENERATE_DEFAULT_SPEEDS(n),		 \
 	.mdio = UTIL_AND(UTIL_NOT(IS_FIXED_LINK(n)),			 \
-			 DEVICE_DT_GET(DT_INST_BUS(n)))			 \
+			 DEVICE_DT_GET(DT_INST_BUS(n))),		 \
+	RESET_GPIO(n)							 \
 };
 
 #define PHY_MII_DATA(n)							 \

dts/bindings/ethernet/phy/ethernet-phy.yaml

@@ -26,3 +26,15 @@ properties:
   default-speeds:
     default: ["10BASE Half-Duplex", "10BASE Full-Duplex", "100BASE Half-Duplex",
               "100BASE Full-Duplex", "1000BASE Half-Duplex", "1000BASE Full-Duplex"]
+  reset-gpios:
+    type: phandle-array
+    description: Reset pin.
+      Optional GPIO used to reset the PHY
+  reset-assert-duration-us:
+    type: int
+    description:
+      Minimum duration in microseconds to assert the reset-gpios pin.
+  reset-deassertion-timeout-ms:
+    type: int
+    description:
+      Timeout in milliseconds after the reset-gpios pin is deasserted.