From: Sergei Shtylyov <sergei.shtyl...@cogentembedded.com> 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.shtyl...@cogentembedded.com> Acked-by: Rob Herring <r...@kernel.org> Acked-by: Florian Fainelli <f.faine...@gmail.com> [geert: Propagate actual errors from fwnode_get_named_gpiod()] Signed-off-by: Geert Uytterhoeven <geert+rene...@glider.be> --- This has gained a dependency on "[PATCH v2] of_mdio: Fix broken PHY IRQ in case of probe deferral" (https://www.spinics.net/lists/linux-renesas-soc/msg19442.html), as v3 needs to propagate errors from of_mdiobus_register_phy() and of_mdiobus_register_device() [*]. v3: - Fix fwnode_get_named_gpiod() call due to added parameters (which allowed to eliminate the gpiod_direction_output() call), - Undelete one blank line in the AT803x driver, - Resolve rejects, refresh patch, - Reword/reformat changelog, - Take over from Sergei, - Add Acked-by, - Remove unneeded gpiod check, as gpiod_set_value() handles NULL fine, - Handle fwnode_get_named_gpiod() errors correctly: - -ENOENT is ignored (the GPIO is optional), and turned into NULL, which allowed to remove all later !IS_ERR() checks, - Other errors (incl. -EPROBE_DEFER) are propagated [*], v2: - Reformat changelog, - Resolve rejects, refresh patch. --- Documentation/devicetree/bindings/net/phy.txt | 2 ++ drivers/net/phy/at803x.c | 18 +++------------ drivers/net/phy/mdio_bus.c | 4 ++++ drivers/net/phy/mdio_device.c | 26 +++++++++++++++++++-- drivers/net/phy/phy_device.c | 33 +++++++++++++++++++++++++-- drivers/of/of_mdio.c | 23 +++++++++++++++++++ include/linux/mdio.h | 3 +++ include/linux/phy.h | 5 ++++ 8 files changed, 95 insertions(+), 19 deletions(-) diff --git a/Documentation/devicetree/bindings/net/phy.txt b/Documentation/devicetree/bindings/net/phy.txt index 77d0b2a61ffa96fc..c05479f5ac7cc837 100644 --- a/Documentation/devicetree/bindings/net/phy.txt +++ b/Documentation/devicetree/bindings/net/phy.txt @@ -53,6 +53,8 @@ Optional Properties: to ensure the integrated PHY is used. The absence of this property indicates the muxers should be configured so that the external PHY is used. +- reset-gpios: The GPIO phandle and specifier for the PHY reset signal. + Example: ethernet-phy@0 { diff --git a/drivers/net/phy/at803x.c b/drivers/net/phy/at803x.c index 5f93e6add56394f2..15b4560aeb5de759 100644 --- a/drivers/net/phy/at803x.c +++ b/drivers/net/phy/at803x.c @@ -71,7 +71,6 @@ MODULE_LICENSE("GPL"); struct at803x_priv { bool phy_reset:1; - struct gpio_desc *gpiod_reset; }; struct at803x_context { @@ -254,22 +253,11 @@ static int at803x_probe(struct phy_device *phydev) { struct device *dev = &phydev->mdio.dev; struct at803x_priv *priv; - struct gpio_desc *gpiod_reset; priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; - if (phydev->drv->phy_id != ATH8030_PHY_ID) - goto does_not_require_reset_workaround; - - gpiod_reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW); - if (IS_ERR(gpiod_reset)) - return PTR_ERR(gpiod_reset); - - priv->gpiod_reset = gpiod_reset; - -does_not_require_reset_workaround: phydev->priv = priv; return 0; @@ -343,14 +331,14 @@ static void at803x_link_change_notify(struct phy_device *phydev) * cannot recover from by software. */ if (phydev->state == PHY_NOLINK) { - if (priv->gpiod_reset && !priv->phy_reset) { + if (phydev->mdio.reset && !priv->phy_reset) { struct at803x_context context; at803x_context_save(phydev, &context); - gpiod_set_value(priv->gpiod_reset, 1); + phy_device_reset(phydev, 1); msleep(1); - gpiod_set_value(priv->gpiod_reset, 0); + phy_device_reset(phydev, 0); msleep(1); at803x_context_restore(phydev, &context); diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c index 2df7b62c1a36811e..da6e5366d641a416 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> @@ -420,6 +421,9 @@ 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); } 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 @@ -12,6 +12,8 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/errno.h> +#include <linux/gpio.h> +#include <linux/gpio/consumer.h> #include <linux/init.h> #include <linux/interrupt.h> #include <linux/kernel.h> @@ -114,6 +116,12 @@ void mdio_device_remove(struct mdio_device *mdiodev) } EXPORT_SYMBOL(mdio_device_remove); +void mdio_device_reset(struct mdio_device *mdiodev, int value) +{ + gpiod_set_value(mdiodev->reset, value); +} +EXPORT_SYMBOL(mdio_device_reset); + /** * mdio_probe - probe an MDIO device * @dev: device to probe @@ -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); + /* Assert the reset signal */ + mdio_device_reset(mdiodev, 1); + } + return err; } @@ -140,9 +155,16 @@ 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) { + /* Deassert the reset signal */ + mdio_device_reset(mdiodev, 0); + mdiodrv->remove(mdiodev); + /* Assert the reset signal */ + mdio_device_reset(mdiodev, 1); + } + return 0; } 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 @@ -632,6 +632,9 @@ int phy_device_register(struct phy_device *phydev) if (err) return err; + /* Deassert the reset signal */ + phy_device_reset(phydev, 0); + /* Run all of the fixups for this PHY */ err = phy_scan_fixups(phydev); if (err) { @@ -647,9 +650,15 @@ int phy_device_register(struct phy_device *phydev) goto out; } + /* Assert the reset signal */ + phy_device_reset(phydev, 1); + return 0; out: + /* Assert the reset signal */ + phy_device_reset(phydev, 1); + mdiobus_unregister_device(&phydev->mdio); return err; } @@ -849,6 +858,9 @@ int phy_init_hw(struct phy_device *phydev) { int ret = 0; + /* Deassert the reset signal */ + phy_device_reset(phydev, 0); + if (!phydev->drv || !phydev->drv->config_init) return 0; @@ -1126,6 +1138,9 @@ void phy_detach(struct phy_device *phydev) put_device(&phydev->mdio.dev); if (ndev_owner != bus->owner) module_put(bus->owner); + + /* Assert the reset signal */ + phy_device_reset(phydev, 1); } EXPORT_SYMBOL(phy_detach); @@ -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); + /* Assert the reset signal */ + phy_device_reset(phydev, 1); + } + mutex_unlock(&phydev->lock); return err; @@ -1829,8 +1851,15 @@ static int phy_remove(struct device *dev) phydev->state = PHY_DOWN; mutex_unlock(&phydev->lock); - if (phydev->drv && phydev->drv->remove) + if (phydev->drv && phydev->drv->remove) { + /* Deassert the reset signal */ + phy_device_reset(phydev, 0); + phydev->drv->remove(phydev); + + /* Assert the reset signal */ + phy_device_reset(phydev, 1); + } phydev->drv = NULL; return 0; diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c index 98258583abb0b405..3d044119c032d176 100644 --- a/drivers/of/of_mdio.c +++ b/drivers/of/of_mdio.c @@ -47,6 +47,7 @@ static int of_get_phy_id(struct device_node *device, u32 *phy_id) static int of_mdiobus_register_phy(struct mii_bus *mdio, struct device_node *child, u32 addr) { + struct gpio_desc *gpiod; struct phy_device *phy; bool is_c45; int rc; @@ -55,10 +56,22 @@ static int of_mdiobus_register_phy(struct mii_bus *mdio, is_c45 = of_device_is_compatible(child, "ethernet-phy-ieee802.3-c45"); + /* Deassert the optional reset signal */ + gpiod = fwnode_get_named_gpiod(&child->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); + if (!is_c45 && !of_get_phy_id(child, &phy_id)) phy = phy_device_create(mdio, addr, phy_id, 0, NULL); else phy = get_phy_device(mdio, addr, is_c45); + + /* Assert the reset signal again */ + gpiod_set_value(gpiod, 1); + if (IS_ERR(phy)) return PTR_ERR(phy); @@ -81,6 +94,7 @@ static int of_mdiobus_register_phy(struct mii_bus *mdio, * can be looked up later */ of_node_get(child); phy->mdio.dev.of_node = child; + phy->mdio.reset = gpiod; /* All data is now stored in the phy struct; * register it */ @@ -100,6 +114,7 @@ static int of_mdiobus_register_device(struct mii_bus *mdio, struct device_node *child, u32 addr) { struct mdio_device *mdiodev; + struct gpio_desc *gpiod; int rc; mdiodev = mdio_device_create(mdio, addr); @@ -112,6 +127,14 @@ static int of_mdiobus_register_device(struct mii_bus *mdio, of_node_get(child); mdiodev->dev.of_node = child; + gpiod = fwnode_get_named_gpiod(&child->fwnode, "reset-gpios", 0, + GPIOD_ASIS, "PHY reset"); + if (PTR_ERR(gpiod) == -ENOENT) + gpiod = NULL; + else if (IS_ERR(gpiod)) + return PTR_ERR(gpiod); + mdiodev->reset = gpiod; + /* All data is now stored in the mdiodev struct; register it. */ rc = mdio_device_register(mdiodev); if (rc) { diff --git a/include/linux/mdio.h b/include/linux/mdio.h index ca08ab16ecdc9b78..92d4e55ffe675637 100644 --- a/include/linux/mdio.h +++ b/include/linux/mdio.h @@ -12,6 +12,7 @@ #include <uapi/linux/mdio.h> #include <linux/mod_devicetable.h> +struct gpio_desc; struct mii_bus; /* Multiple levels of nesting are possible. However typically this is @@ -39,6 +40,7 @@ struct mdio_device { /* Bus address of the MDIO device (0-31) */ int addr; int flags; + struct gpio_desc *reset; }; #define to_mdio_device(d) container_of(d, struct mdio_device, dev) @@ -71,6 +73,7 @@ void mdio_device_free(struct mdio_device *mdiodev); struct mdio_device *mdio_device_create(struct mii_bus *bus, int addr); int mdio_device_register(struct mdio_device *mdiodev); void mdio_device_remove(struct mdio_device *mdiodev); +void mdio_device_reset(struct mdio_device *mdiodev, int value); int mdio_driver_register(struct mdio_driver *drv); void mdio_driver_unregister(struct mdio_driver *drv); int mdio_device_bus_match(struct device *dev, struct device_driver *drv); diff --git a/include/linux/phy.h b/include/linux/phy.h index d78cd01ea5131018..175f3a6a61abcf0f 100644 --- a/include/linux/phy.h +++ b/include/linux/phy.h @@ -847,6 +847,11 @@ static inline int phy_read_status(struct phy_device *phydev) return phydev->drv->read_status(phydev); } +static inline void phy_device_reset(struct phy_device *phydev, int value) +{ + mdio_device_reset(&phydev->mdio, value); +} + #define phydev_err(_phydev, format, args...) \ dev_err(&_phydev->mdio.dev, format, ##args) -- 2.7.4
