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_bus.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'drivers/net/phy/mdio_bus.c') diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c index 2df7b62c1a36..8f8b7747c54b 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -38,6 +38,7 @@ #include #include #include +#include #include @@ -48,9 +49,26 @@ int mdiobus_register_device(struct mdio_device *mdiodev) { + struct gpio_desc *gpiod = NULL; + if (mdiodev->bus->mdio_map[mdiodev->addr]) return -EBUSY; + /* Deassert the optional reset signal */ + if (mdiodev->dev.of_node) + gpiod = fwnode_get_named_gpiod(&mdiodev->dev.of_node->fwnode, + "reset-gpios", 0, GPIOD_OUT_LOW, + "PHY reset"); + if (PTR_ERR(gpiod) == -ENOENT) + gpiod = NULL; + else if (IS_ERR(gpiod)) + return PTR_ERR(gpiod); + + mdiodev->reset = gpiod; + + /* Assert the reset signal again */ + mdio_device_reset(mdiodev, 1); + mdiodev->bus->mdio_map[mdiodev->addr] = mdiodev; return 0; @@ -420,6 +438,9 @@ void mdiobus_unregister(struct mii_bus *bus) if (!mdiodev) continue; + if (mdiodev->reset) + gpiod_put(mdiodev->reset); + mdiodev->device_remove(mdiodev); mdiodev->device_free(mdiodev); } -- cgit