diff options
| author | Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> | 2017-12-04 15:35:05 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-12-05 20:51:19 +0300 |
| commit | bafbdd527d569c8200521f2f7579f65a044271be (patch) | |
| tree | 51db9962c079c2ca76a5e9f6d3cb2dc222999c37 /drivers/net/phy/mdio_bus.c | |
| parent | 62b32379fd124fea521484ba7e220d8a449f0b59 (diff) | |
| download | linux-bafbdd527d569c8200521f2f7579f65a044271be.tar.xz | |
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 <sergei.shtylyov@cogentembedded.com>
Acked-by: Rob Herring <robh@kernel.org>
[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 <geert+renesas@glider.be>
Tested-by: Richard Leitner <richard.leitner@skidata.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/phy/mdio_bus.c')
| -rw-r--r-- | drivers/net/phy/mdio_bus.c | 21 |
1 files changed, 21 insertions, 0 deletions
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 <linux/phy.h> #include <linux/io.h> #include <linux/uaccess.h> +#include <linux/gpio/consumer.h> #include <asm/irq.h> @@ -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); } |