Re: GPIO registration for external Ethernet PHY oscillator enable/disable

From: Linus Walleij
Date: Tue Oct 07 2014 - 10:09:50 EST


On Fri, Sep 26, 2014 at 10:04 PM, Michael Welling <mwelling@xxxxxxxxxxx> wrote:
> On Fri, Sep 26, 2014 at 10:16:51AM -0700, Florian Fainelli wrote:
>>
>> Yes and no, this might feel like the wrong place, but ultimately, the
>> Ethernet MAC is a consumer of the PHY device, and is in control, through
>> the PHY library of how and when the PHY gets to be powered off.
>>
>
> So here is the patch that I made that hooks into the macb driver.
>
> Please look it over and tell me if we are on the same page.
>
> The thing that bothers me about this solution is that it will only work with the macb driver.
> So everytime I use the same PHY/OSC combo with a different SoC I will have to do another patch.
>
> diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c
> index e4e34b6..8cd363f 100644
> --- a/drivers/net/ethernet/cadence/macb.c
> +++ b/drivers/net/ethernet/cadence/macb.c
> @@ -28,6 +28,7 @@
> #include <linux/of.h>
> #include <linux/of_device.h>
> #include <linux/of_net.h>
> +#include <linux/of_gpio.h>

No please,
#include <linux/gpio/consumer.h>

> @@ -1833,6 +1834,16 @@ static int __init macb_probe(struct platform_device *pdev)
> bp->phy_interface = err;
> }
>
> + bp->phy_osc_gpio = of_get_named_gpio(pdev->dev.of_node, "osc-gpio", 0);
> +
> + if (gpio_is_valid(bp->phy_osc_gpio))
> + {
> + if (gpio_request(bp->phy_osc_gpio, "osc-gpio") != 0) {
> + pr_info("Oscillator GPIO not available.\n");
> + bp->phy_osc_gpio = 0;
> + }
> + }


No,
bp->phy_osc_gpiod = devm_gpiod_get(&pdev->dev, "osc-gpio", 0);

And error handling.

> + if (gpio_is_valid(bp->phy_osc_gpio))
> + gpio_set_value_cansleep(bp->phy_osc_gpio, 0);
> +

if (bp->phy_osc_gpiod)
gpiod_set_...

> + if (gpio_is_valid(bp->phy_osc_gpio))
> + gpio_set_value_cansleep(bp->phy_osc_gpio, 1);

Dito.

> phy_interface_t phy_interface;
> + int phy_osc_gpio;

struct gpio_desc *phy_osc_gpiod;

Yours,
Linus Walleij
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