Hello, On Thu, May 12, 2016 at 05:16:56PM +0300, Roger Quadros wrote: > On 12/05/16 17:02, Roger Quadros wrote: > > On 12/05/16 16:50, Nishanth Menon wrote: > >> On 05/12/2016 05:00 AM, Uwe Kleine-König wrote: > >>> The framework only asserts (for now) that the reset gpio is not active. > >>> > >>> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> > >>> --- > >>> Documentation/devicetree/bindings/net/phy.txt | 3 +++ > >>> drivers/net/phy/phy_device.c | 8 ++++++++ > >>> 2 files changed, 11 insertions(+) > >>> > >>> diff --git a/Documentation/devicetree/bindings/net/phy.txt b/Documentation/devicetree/bindings/net/phy.txt > >>> index bc1c3c8bf8fa..c00a9a894547 100644 > >>> --- a/Documentation/devicetree/bindings/net/phy.txt > >>> +++ b/Documentation/devicetree/bindings/net/phy.txt > >>> @@ -35,6 +35,8 @@ Optional Properties: > >>> - broken-turn-around: If set, indicates the PHY device does not correctly > >>> release the turn around line low at the end of a MDIO transaction. > >>> > >>> +- reset-gpios: Reference to a GPIO used to reset the phy. > >>> + > >>> Example: > >>> > >>> ethernet-phy@0 { > >>> @@ -42,4 +44,5 @@ ethernet-phy@0 { > >>> interrupt-parent = <40000>; > >>> interrupts = <35 1>; > >>> reg = <0>; > >>> + reset-gpios = <&gpio1 17 GPIO_ACTIVE_LOW>; > >>> }; > >>> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c > >>> index e551f3a89cfd..7d666ab47271 100644 > >>> --- a/drivers/net/phy/phy_device.c > >>> +++ b/drivers/net/phy/phy_device.c > >>> @@ -34,6 +34,7 @@ > >>> #include <linux/io.h> > >>> #include <linux/uaccess.h> > >>> #include <linux/of.h> > >>> +#include <linux/gpio/consumer.h> > >>> > >>> #include <asm/irq.h> > >>> > >>> @@ -1569,9 +1570,16 @@ static int phy_probe(struct device *dev) > >>> struct device_driver *drv = phydev->mdio.dev.driver; > >>> struct phy_driver *phydrv = to_phy_driver(drv); > >>> int err = 0; > >>> + struct gpio_descs *reset_gpios; > >>> > >>> phydev->drv = phydrv; > >>> > >>> + /* take phy out of reset */ > >>> + reset_gpios = devm_gpiod_get_array_optional(dev, "reset", > >>> + GPIOD_OUT_LOW); > >>> + if (IS_ERR(reset_gpios)) > >>> + return PTR_ERR(reset_gpios); > >>> + > >>> /* Disable the interrupt if the PHY doesn't support it > >>> * but the interrupt is still a valid one > >>> */ > >>> > >> > >> This looks like the right approach to me at least: I see that TI EVMs > >> will also benefit with this approach. > >> > > > > Agreed. Although on some of our boards we actually need a RESET pulse > > to get the PHY in a sane state. I can send a patch on top for that. > > > > I think I replied too early. Will phy_probe() be called at all if the > PHY is not detected on the MDIO bus? > If not then this approach is not sufficient for some of the TI boards. > e.g. am57xx-idk. > I think the reset needs to be done at MDIO bus level before it enumerates > the PHYs so that we know the PHY is in an enumerable state. I have this in the device tree: &davinci_mdio { pinctrl-names = "default", "sleep"; pinctrl-0 = <&davinci_mdio_default>; pinctrl-1 = <&davinci_mdio_sleep>; status = "okay"; phy0: ethernet-phy@0 { compatible = "ethernet-phy-id2000.a212", "ethernet-phy-ieee802.3-c22"; reg = <0>; interrupt-parent = <&gpio2>; interrupts = <2 8>; pinctrl-names = "default"; pinctrl-0 = <&phy0_pins>; reset-gpios = <&gpio2 9 GPIO_ACTIVE_LOW>; }; phy1: ethernet-phy@2 { compatible = "ethernet-phy-id2000.a212", "ethernet-phy-ieee802.3-c22"; reg = <2>; interrupt-parent = <&gpio0>; interrupts = <2 8>; pinctrl-names = "default"; pinctrl-0 = <&phy1_pins>; reset-gpios = <&gpio2 11 GPIO_ACTIVE_LOW>; }; }; With the phy id values specified in the compatible the mdio bus is only accessed when the reset pin was handled. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html