mdio_bus: Issue GPIO RESET to PHYs.
Some boards [1] leave the PHYs at an invalid state
during system power-up or reset thus causing unreliability
issues with the PHY which manifests as PHY not being detected
or link not functional. To fix this, these PHYs need to be RESET
via a GPIO connected to the PHY's RESET pin.
Some boards have a single GPIO controlling the PHY RESET pin of all
PHYs on the bus whereas some others have separate GPIOs controlling
individual PHY RESETs.
In both cases, the RESET de-assertion cannot be done in the PHY driver
as the PHY will not probe till its reset is de-asserted.
So do the RESET de-assertion in the MDIO bus driver.
[1] - am572x-idk, am571x-idk, a437x-idk
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 624cecf..37ca77d 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -217,6 +217,13 @@ struct mii_bus {
* matching its address
*/
int irq[PHY_MAX_ADDR];
+
+ /* GPIO reset pulse width in microseconds */
+ int reset_delay_us;
+ /* Number of reset GPIOs */
+ int num_reset_gpios;
+ /* Array of RESET GPIO descriptors */
+ struct gpio_desc **reset_gpiod;
};
#define to_mii_bus(d) container_of(d, struct mii_bus, dev)