From: Andrew Lunn <andrew@lunn.ch>

Linux LEDs can be software controlled via the brightness file in /sys.
LED drivers need to implement a brightness_set function which the core
will call. Implement an intermediary in phy_device, which will call
into the phy driver if it implements the necessary function.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
 drivers/net/phy/phy_device.c | 15 ++++++++++++---
 include/linux/phy.h          | 11 +++++++++++
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 39af989947f9..141d63ef3897 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -2991,11 +2991,18 @@ static bool phy_drv_supports_irq(struct phy_driver *phydrv)
 	return phydrv->config_intr && phydrv->handle_interrupt;
 }
 
-/* Dummy implementation until calls into PHY driver are added */
 static int phy_led_set_brightness(struct led_classdev *led_cdev,
 				  enum led_brightness value)
 {
-	return 0;
+	struct phy_led *phyled = to_phy_led(led_cdev);
+	struct phy_device *phydev = phyled->phydev;
+	int err;
+
+	mutex_lock(&phydev->lock);
+	err = phydev->drv->led_brightness_set(phydev, phyled->index, value);
+	mutex_unlock(&phydev->lock);
+
+	return err;
 }
 
 static int of_phy_led(struct phy_device *phydev,
@@ -3012,12 +3019,14 @@ static int of_phy_led(struct phy_device *phydev,
 		return -ENOMEM;
 
 	cdev = &phyled->led_cdev;
+	phyled->phydev = phydev;
 
 	err = of_property_read_u32(led, "reg", &phyled->index);
 	if (err)
 		return err;
 
-	cdev->brightness_set_blocking = phy_led_set_brightness;
+	if (phydev->drv->led_brightness_set)
+		cdev->brightness_set_blocking = phy_led_set_brightness;
 	cdev->max_brightness = 1;
 	init_data.devicename = dev_name(&phydev->mdio.dev);
 	init_data.fwnode = of_fwnode_handle(led);
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 11fb76a1c507..2a5ee66b79b0 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -841,15 +841,19 @@ struct phy_plca_status {
  * struct phy_led: An LED driven by the PHY
  *
  * @list: List of LEDs
+ * @phydev: PHY this LED is attached to
  * @led_cdev: Standard LED class structure
  * @index: Number of the LED
  */
 struct phy_led {
 	struct list_head list;
+	struct phy_device *phydev;
 	struct led_classdev led_cdev;
 	u32 index;
 };
 
+#define to_phy_led(d) container_of(d, struct phy_led, led_cdev)
+
 /**
  * struct phy_driver - Driver structure for a particular PHY type
  *
@@ -1072,6 +1076,13 @@ struct phy_driver {
 	/** @get_plca_status: Return the current PLCA status info */
 	int (*get_plca_status)(struct phy_device *dev,
 			       struct phy_plca_status *plca_st);
+
+	/* Set a PHY LED brightness. Index indicates which of the PHYs
+	 * led should be set. Value follows the standard LED class meaning,
+	 * e.g. LED_OFF, LED_HALF, LED_FULL.
+	 */
+	int (*led_brightness_set)(struct phy_device *dev,
+				  u32 index, enum led_brightness value);
 };
 #define to_phy_driver(d) container_of(to_mdio_common_driver(d),		\
 				      struct phy_driver, mdiodrv)
-- 
2.39.2

On 3/27/2023 7:10 AM, Christian Marangi wrote:
> From: Andrew Lunn <andrew@lunn.ch>
> 
> Linux LEDs can be software controlled via the brightness file in /sys.
> LED drivers need to implement a brightness_set function which the core
> will call. Implement an intermediary in phy_device, which will call
> into the phy driver if it implements the necessary function.
> 
> Signed-off-by: Andrew Lunn <andrew@lunn.ch>
> Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>

> +	int (*led_brightness_set)(struct phy_device *dev,
> +				  u32 index, enum led_brightness value);

I think I would have made this an u8, 4 billion LEDs, man, that's a lot!
-- 
Florian

On Thu, Apr 13, 2023 at 06:57:51AM -0700, Florian Fainelli wrote:
> 
> 
> On 3/27/2023 7:10 AM, Christian Marangi wrote:
> > From: Andrew Lunn <andrew@lunn.ch>
> > 
> > Linux LEDs can be software controlled via the brightness file in /sys.
> > LED drivers need to implement a brightness_set function which the core
> > will call. Implement an intermediary in phy_device, which will call
> > into the phy driver if it implements the necessary function.
> > 
> > Signed-off-by: Andrew Lunn <andrew@lunn.ch>
> > Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
> 
> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
> 
> > +	int (*led_brightness_set)(struct phy_device *dev,
> > +				  u32 index, enum led_brightness value);
> 
> I think I would have made this an u8, 4 billion LEDs, man, that's a lot!

That can be done. We need to change:

        err = of_property_read_u32(led, "reg", &phyled->index);
        if (err)
                return err;

to a u8, to avoid overflow problems in other places. It looks like
of_property_read_u8() does the correct thing if somebody tried to use
4 billion - 1.

  Andrew

On Thu, Apr 13, 2023 at 06:57:51AM -0700, Florian Fainelli wrote:
> 
> 
> On 3/27/2023 7:10 AM, Christian Marangi wrote:
> > From: Andrew Lunn <andrew@lunn.ch>
> > 
> > Linux LEDs can be software controlled via the brightness file in /sys.
> > LED drivers need to implement a brightness_set function which the core
> > will call. Implement an intermediary in phy_device, which will call
> > into the phy driver if it implements the necessary function.
> > 
> > Signed-off-by: Andrew Lunn <andrew@lunn.ch>
> > Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
> 
> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
> 
> > +	int (*led_brightness_set)(struct phy_device *dev,
> > +				  u32 index, enum led_brightness value);
> 
> I think I would have made this an u8, 4 billion LEDs, man, that's a lot!

If andrew is ok we can still consider to reduce it. (but just to joke
about it... A MAN CAN DREAM OF A FULL HD SCREEN ON THEIR OWN SPECIAL
PORT)

-- 
	Ansuel

On 4/12/2023 4:11 PM, Christian Marangi wrote:
> On Thu, Apr 13, 2023 at 06:57:51AM -0700, Florian Fainelli wrote:
>>
>>
>> On 3/27/2023 7:10 AM, Christian Marangi wrote:
>>> From: Andrew Lunn <andrew@lunn.ch>
>>>
>>> Linux LEDs can be software controlled via the brightness file in /sys.
>>> LED drivers need to implement a brightness_set function which the core
>>> will call. Implement an intermediary in phy_device, which will call
>>> into the phy driver if it implements the necessary function.
>>>
>>> Signed-off-by: Andrew Lunn <andrew@lunn.ch>
>>> Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
>>
>> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
>>
>>> +	int (*led_brightness_set)(struct phy_device *dev,
>>> +				  u32 index, enum led_brightness value);
>>
>> I think I would have made this an u8, 4 billion LEDs, man, that's a lot!
> 
> If andrew is ok we can still consider to reduce it. (but just to joke
> about it... A MAN CAN DREAM OF A FULL HD SCREEN ON THEIR OWN SPECIAL
> PORT)

Humm just thought of something else, is it OK for led_brightness_set and 
led_blink_set to call into functions that might require sleeping (MDIO, 
I2C, SPI, etc.)?
-- 
Florian

> Humm just thought of something else, is it OK for led_brightness_set and
> led_blink_set to call into functions that might require sleeping (MDIO, I2C,
> SPI, etc.)?

Hi Florian

That is fine. The LED class is similar to GPIOs. There is a can sleep
version, and an atomic version. For phylib we are using the can sleep
version. The LED core then hides the differences from the users.

    Andrew