Subject: Re: [PATCH] phy: add support for a reset-gpio specification

From: Nishanth Menon <[email-masked]>
Date: Thu, 12 May 2016 08:50:34 -0500

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 <[email-masked]>
> ---
>  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.

-- 
Regards,
Nishanth Menon