[net-next PATCH v10 3/5] net: phy: add support for PHY LEDs polarity modes

[Christian Marangi <ansuelsmth@gmail.com>]

Add support for PHY LEDs polarity modes. Some PHY require LED to be set
to active low to be turned ON. Adds support for this by declaring
active-low property in DT.

PHY driver needs to declare .led_polarity_set() to configure LED
polarity modes. Function will pass the index with the LED index and a
bitmap with all the required modes to set.

Current supported modes are:
- active-low with the flag PHY_LED_ACTIVE_LOW. LED is set to active-low
  to turn it ON.
- inactive-high-impedance with the flag PHY_LED_INACTIVE_HIGH_IMPEDANCE.
  LED is set to high impedance to turn it OFF.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
Changes v10:
- Add Review tag
Changes v9:
- Make LED probe fail if modes asked but not supported
- Fix wrong function description
Changes v5:
- Rework to LED modes bitmap
Changes v4:
- Drop for global active-low
- Rework to polarity option (for marvell10g series support)
Changes v3:
- Out of RFC
Changes v2:
- Add this patch

 drivers/net/phy/phy_device.c | 16 ++++++++++++++++
 include/linux/phy.h          | 22 ++++++++++++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 3611ea64875e..dd778c7fde1d 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -3097,6 +3097,7 @@ static int of_phy_led(struct phy_device *phydev,
 	struct device *dev = &phydev->mdio.dev;
 	struct led_init_data init_data = {};
 	struct led_classdev *cdev;
+	unsigned long modes = 0;
 	struct phy_led *phyled;
 	u32 index;
 	int err;
@@ -3114,6 +3115,21 @@ static int of_phy_led(struct phy_device *phydev,
 	if (index > U8_MAX)
 		return -EINVAL;
 
+	if (of_property_read_bool(led, "active-low"))
+		set_bit(PHY_LED_ACTIVE_LOW, &modes);
+	if (of_property_read_bool(led, "inactive-high-impedance"))
+		set_bit(PHY_LED_INACTIVE_HIGH_IMPEDANCE, &modes);
+
+	if (modes) {
+		/* Return error if asked to set polarity modes but not supported */
+		if (!phydev->drv->led_polarity_set)
+			return -EINVAL;
+
+		err = phydev->drv->led_polarity_set(phydev, index, modes);
+		if (err)
+			return err;
+	}
+
 	phyled->index = index;
 	if (phydev->drv->led_brightness_set)
 		cdev->brightness_set_blocking = phy_led_set_brightness;
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 684efaeca07c..c9994a59ca2e 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -852,6 +852,15 @@ struct phy_plca_status {
 	bool pst;
 };
 
+/* Modes for PHY LED configuration */
+enum phy_led_modes {
+	PHY_LED_ACTIVE_LOW = 0,
+	PHY_LED_INACTIVE_HIGH_IMPEDANCE = 1,
+
+	/* keep it last */
+	__PHY_LED_MODES_NUM,
+};
+
 /**
  * struct phy_led: An LED driven by the PHY
  *
@@ -1145,6 +1154,19 @@ struct phy_driver {
 	int (*led_hw_control_get)(struct phy_device *dev, u8 index,
 				  unsigned long *rules);
 
+	/**
+	 * @led_polarity_set: Set the LED polarity modes
+	 * @dev: PHY device which has the LED
+	 * @index: Which LED of the PHY device
+	 * @modes: bitmap of LED polarity modes
+	 *
+	 * Configure LED with all the required polarity modes in @modes
+	 * to make it correctly turn ON or OFF.
+	 *
+	 * Returns 0, or an error code.
+	 */
+	int (*led_polarity_set)(struct phy_device *dev, int index,
+				unsigned long modes);
 };
 #define to_phy_driver(d) container_of(to_mdio_common_driver(d),		\
 				      struct phy_driver, mdiodrv)
-- 
2.43.0