From bafbdd527d569c8200521f2f7579f65a044271be Mon Sep 17 00:00:00 2001 From: Sergei Shtylyov Date: Mon, 4 Dec 2017 13:35:05 +0100 Subject: phylib: Add device reset GPIO support 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 Acked-by: Rob Herring [geert: Propagate actual errors from fwnode_get_named_gpiod()] [geert: Avoid destroying initial setup] [geert: Consolidate GPIO descriptor acquiring code] Signed-off-by: Geert Uytterhoeven Tested-by: Richard Leitner Signed-off-by: David S. Miller --- drivers/net/phy/mdio_device.c | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-) (limited to 'drivers/net/phy/mdio_device.c') diff --git a/drivers/net/phy/mdio_device.c b/drivers/net/phy/mdio_device.c index e24f28924af8..75d97dd9fb28 100644 --- a/drivers/net/phy/mdio_device.c +++ b/drivers/net/phy/mdio_device.c @@ -12,6 +12,8 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include +#include +#include #include #include #include @@ -114,6 +116,13 @@ void mdio_device_remove(struct mdio_device *mdiodev) } EXPORT_SYMBOL(mdio_device_remove); +void mdio_device_reset(struct mdio_device *mdiodev, int value) +{ + if (mdiodev->reset) + gpiod_set_value(mdiodev->reset, value); +} +EXPORT_SYMBOL(mdio_device_reset); + /** * mdio_probe - probe an MDIO device * @dev: device to probe @@ -128,8 +137,16 @@ 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 (err) { + /* Assert the reset signal */ + mdio_device_reset(mdiodev, 1); + } + } return err; } @@ -140,9 +157,13 @@ static int mdio_remove(struct device *dev) struct device_driver *drv = mdiodev->dev.driver; struct mdio_driver *mdiodrv = to_mdio_driver(drv); - if (mdiodrv->remove) + if (mdiodrv->remove) { mdiodrv->remove(mdiodev); + /* Assert the reset signal */ + mdio_device_reset(mdiodev, 1); + } + return 0; } -- cgit v1.2.3