Hello!
On 10/20/2017 11:14 AM, Geert Uytterhoeven wrote:
From: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>
The PHY devices sometimes do have their reset signal (maybe even power
supply?) tied to some GPIO and sometimes it also does happen that a boot
loader does not leave it deasserted. So far this issue has been attacked
from (as I believe) a wrong angle: by teaching the MAC driver to manipulate
the GPIO in question; that solution, when applied to the device trees, led
to adding the PHY reset GPIO properties to the MAC device node, with one
exception: Cadence MACB driver which could handle the "reset-gpios" prop
in a PHY device subnode. I believe that the correct approach is to teach
the 'phylib' to get the MDIO device reset GPIO from the device tree node
corresponding to this device -- which this patch is doing...
Note that I had to modify the AT803x PHY driver as it would stop working
otherwise -- it made use of the reset GPIO for its own purposes...
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>
Acked-by: Rob Herring <robh@xxxxxxxxxx>
Acked-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
[geert: Propagate actual errors from fwnode_get_named_gpiod()]
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
[...]
diff --git a/drivers/net/phy/mdio_device.c b/drivers/net/phy/mdio_device.c
index e24f28924af8953d..6926db11ae888174 100644
--- a/drivers/net/phy/mdio_device.c
+++ b/drivers/net/phy/mdio_device.c
[...]
@@ -128,9 +136,16 @@ static int mdio_probe(struct device *dev)
struct mdio_driver *mdiodrv = to_mdio_driver(drv);
int err = 0;
- if (mdiodrv->probe)
+ if (mdiodrv->probe) {
+ /* Deassert the reset signal */
+ mdio_device_reset(mdiodev, 0);
+
err = mdiodrv->probe(mdiodev);
If the probe() method performs some register setup...
+ /* Assert the reset signal */
+ mdio_device_reset(mdiodev, 1);
... this reset would kill that setup. Hence we shouldn't drive the reset
signal at least when the probe() method succeeds.
+ }
+
return err;
}
[...]
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 67f25ac29025c539..e694b0ecf780d096 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
[...]
@@ -1811,9 +1826,16 @@ static int phy_probe(struct device *dev)
/* Set the state to READY by default */
phydev->state = PHY_READY;
- if (phydev->drv->probe)
+ if (phydev->drv->probe) {
+ /* Deassert the reset signal */
+ phy_device_reset(phydev, 0);
+
err = phydev->drv->probe(phydev);
If the probe() method performs some register setup (as does the LXT PHY
driver!)...
+ /* Assert the reset signal */
+ phy_device_reset(phydev, 1);
... this reset would kill that setup. Hence we shouldn't drive the reset
signal at least when the probe() method succeeds.
+ }
+
mutex_unlock(&phydev->lock);
return err;
[...]
MBR, Sergei
