[RFC/PATCH] net: Rework mdio-ofgpio driver to use of_mdio infrastructure

[Grant Likely]

(adding cc:linuxppc-dev at ozlabs.org)

On Mon, Jul 20, 2009 at 6:20 AM, Mark Ware<mware at elphinstone.net> wrote:
> Changes to the fs_enet driver (aa73832c5a80d6c52c69b18af858d88fa595dd3c)
> cause kernel crashes when using the mdio-ofgpio driver.
>
> The following patch is a fairly naive attempt to replicate similar changes
> made to the fs_enet mii-bitbang drivers.

For a naive attempt, it's really quite good.  However, I'd do it
slightly differently.

You should refactor mdio_gpio_bus_init() to not call
mdiobus_register() at all, and instead just return a pointer to the
unregistered new_bus.  Then mdio_gpio_probe() and mdio_ofgpio_probe()
can call the correct register variant directly.  Fewer ugly #ifdefs
this way.  It also eliminates the need to cast the void* pointer.

Thanks for catching this.

g.

>  drivers/net/phy/mdio-gpio.c |   39 +++++++++++++--------------------------
>  1 files changed, 13 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/net/phy/mdio-gpio.c b/drivers/net/phy/mdio-gpio.c
> index 33984b7..6568176 100644
> --- a/drivers/net/phy/mdio-gpio.c
> +++ b/drivers/net/phy/mdio-gpio.c
> @@ -30,6 +30,7 @@
>
>  #ifdef CONFIG_OF_GPIO
>  #include <linux/of_gpio.h>
> +#include <linux/of_mdio.h>
>  #include <linux/of_platform.h>
>  #endif
>
> @@ -83,7 +84,8 @@ static struct mdiobb_ops mdio_gpio_ops = {
>
>  static int __devinit mdio_gpio_bus_init(struct device *dev,
>                                        struct mdio_gpio_platform_data
> *pdata,
> -                                       int bus_id)
> +                                       int bus_id,
> +                    void *ofdev)
>  {
>        struct mii_bus *new_bus;
>        struct mdio_gpio_info *bitbang;
> @@ -129,7 +131,14 @@ static int __devinit mdio_gpio_bus_init(struct device
> *dev,
>
>        dev_set_drvdata(dev, new_bus);
>
> -       ret = mdiobus_register(new_bus);
> +#ifdef CONFIG_OF_GPIO
> +    if (ofdev)
> +        ret = of_mdiobus_register(new_bus, ((struct of_device *)
> ofdev)->node);
> +    else
> +#else
> +           ret = mdiobus_register(new_bus);
> +#endif
> +
>        if (ret)
>                goto out_free_all;
>
> @@ -168,7 +177,7 @@ static int __devinit mdio_gpio_probe(struct
> platform_device *pdev)
>        if (!pdata)
>                return -ENODEV;
>
> -       return mdio_gpio_bus_init(&pdev->dev, pdata, pdev->id);
> +       return mdio_gpio_bus_init(&pdev->dev, pdata, pdev->id, NULL);
>  }
>
>  static int __devexit mdio_gpio_remove(struct platform_device *pdev)
> @@ -179,28 +188,10 @@ static int __devexit mdio_gpio_remove(struct
> platform_device *pdev)
>  }
>
>  #ifdef CONFIG_OF_GPIO
> -static void __devinit add_phy(struct mdio_gpio_platform_data *pdata,
> -                             struct device_node *np)
> -{
> -       const u32 *data;
> -       int len, id, irq;
> -
> -       data = of_get_property(np, "reg", &len);
> -       if (!data || len != 4)
> -               return;
> -
> -       id = *data;
> -       pdata->phy_mask &= ~(1 << id);
> -
> -       irq = of_irq_to_resource(np, 0, NULL);
> -       if (irq)
> -               pdata->irqs[id] = irq;
> -}
>
>  static int __devinit mdio_ofgpio_probe(struct of_device *ofdev,
>                                         const struct of_device_id *match)
>  {
> -       struct device_node *np = NULL;
>        struct mdio_gpio_platform_data *pdata;
>        int ret;
>
> @@ -218,11 +209,7 @@ static int __devinit mdio_ofgpio_probe(struct of_device
> *ofdev,
>                 goto out_free;
>        pdata->mdio = ret;
>
> -       while ((np = of_get_next_child(ofdev->node, np)))
> -               if (!strcmp(np->type, "ethernet-phy"))
> -                       add_phy(pdata, np);
> -
> -       return mdio_gpio_bus_init(&ofdev->dev, pdata, pdata->mdc);
> +       return mdio_gpio_bus_init(&ofdev->dev, pdata, pdata->mdc, ofdev);
>
>  out_free:
>        kfree(pdata);
> --
> 1.5.6.5
>



-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.