Re: [PATCH/RFC 2/3] ethernet: add a PHY reset GPIO DT binding to sh_eth

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Guennadi,

On Thursday 24 January 2013 17:07:32 Guennadi Liakhovetski wrote:
> If an ethernet PHY can be reset by a GPIO, it can be specified in DT. Add
> a binding and code to parse it, request the GPIO and take the PHY out of
> reset.
> 
> Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
> Cc: devicetree-discuss@lists.ozlabs.org
> Cc: netdev@vger.kernel.org
> ---
>  Documentation/devicetree/bindings/net/sh_ether.txt |    2 ++
>  drivers/net/ethernet/renesas/sh_eth.c              |    9 ++++++++-
>  2 files changed, 10 insertions(+), 1 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/net/sh_ether.txt
> b/Documentation/devicetree/bindings/net/sh_ether.txt index c11e45d..edaf683
> 100644
> --- a/Documentation/devicetree/bindings/net/sh_ether.txt
> +++ b/Documentation/devicetree/bindings/net/sh_ether.txt
> @@ -12,6 +12,7 @@ Required properties:
>  - interrupts:                   Interrupt mapping for the sh_eth interrupt
>                                  sources (vector id).
>  - phy-mode:              String, operation mode of the PHY interface.
> +- phy-reset-gpios:              PHY reset GPIO tuple

If you can't have more than one GPIO here, what about calling it phy-reset-
gpio ?

>  - sh-eth,edmac-endian:          String, endian of sh_eth dmac.
>  - sh-eth,register-type:         String, register type of sh_eth.
>                                  Please select "gigabit", "fast-sh4" or
> @@ -37,6 +38,7 @@ Example (armadillo800eva):
>  		reg = <0xe9a00000 0x800>, <0xe9a01800 0x800>;
>  		interrupts = <0x500>;
>  		phy-mode = "mii";
> +		phy-reset-gpios = <&gpio 18 0>;
>  		sh-eth,edmac-endian = "little";
>  		sh-eth,register-type = "gigabit";
>  		sh-eth,phy-id = <0>;
> diff --git a/drivers/net/ethernet/renesas/sh_eth.c
> b/drivers/net/ethernet/renesas/sh_eth.c index 1f64848..06035a2 100644
> --- a/drivers/net/ethernet/renesas/sh_eth.c
> +++ b/drivers/net/ethernet/renesas/sh_eth.c
> @@ -20,6 +20,7 @@
>   *  the file called "COPYING".
>   */
> 
> +#include <linux/gpio.h>
>  #include <linux/init.h>
>  #include <linux/module.h>
>  #include <linux/kernel.h>
> @@ -33,6 +34,7 @@
>  #include <linux/netdevice.h>
>  #include <linux/of.h>
>  #include <linux/of_device.h>
> +#include <linux/of_gpio.h>
>  #include <linux/of_platform.h>
>  #include <linux/of_address.h>
>  #include <linux/of_irq.h>
> @@ -2376,10 +2378,11 @@ sh_eth_of_get_register_type(struct device_node *np)
>  static struct sh_eth_plat_data *
>  sh_eth_parse_dt(struct device *dev, struct net_device *ndev)
>  {
> -	int ret;
> +	int ret, gpio;
>  	const char *of_str;
>  	struct device_node *np = dev->of_node;
>  	struct sh_eth_plat_data *pdata;
> +	enum of_gpio_flags flags;
> 
>  	pdata = devm_kzalloc(dev, sizeof(struct sh_eth_plat_data),
>  					GFP_KERNEL);
> @@ -2420,6 +2423,10 @@ sh_eth_parse_dt(struct device *dev, struct net_device
> *ndev) else
>  		pdata->needs_init = 0;
> 
> +	gpio = of_get_named_gpio_flags(np, "phy-reset-gpios", 0, &flags);
> +	if (gpio_is_valid(gpio) && !devm_gpio_request(dev, gpio, NULL))
> +		gpio_direction_output(gpio, !!(flags & OF_GPIO_ACTIVE_LOW));

You could use devm_gpio_request_one() here.

Is there no need to reset the phy at runtime ?

> +
>  #ifdef CONFIG_OF_NET
>  	if (!is_valid_ether_addr(ndev->dev_addr)) {
>  		const char *macaddr = of_get_mac_address(np);
-- 
Regards,

Laurent Pinchart