Re: [PATCH v2 2/2] net: davinci_mdio: allow to create phys from dt

[Prabhakar Lad <prabhakar.csengg-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

On Wed, Jul 16, 2014 at 1:13 PM, Grygorii Strashko
<grygorii.strashko-l0cyMroinI0@public.gmane.org> wrote:
> This patch allows to create PHYs from DT in case
> if they are explicitly defined. The of_mdiobus_register() is
> used for such purposes.
>
> For backward compatibility, call  of_mdiobus_register() only in case
> if at least one PHY's child is defined in DT, otherwise rollback to
> mdiobus_register().
>
> Reviewed-by: Santosh Shilimkar <santosh.shilimkar-l0cyMroinI0@public.gmane.org>
> Acked-by: Mugunthan V N <mugunthanvnm-l0cyMroinI0@public.gmane.org>
> Signed-off-by: Grygorii Strashko <grygorii.strashko-l0cyMroinI0@public.gmane.org>

Reviewed-by: Lad, Prabhakar <prabhakar.csengg-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>

Thanks,
--Prabhakar Lad

> ---
> Hi Santosh,
>
> I haven't changed style for long-comments, because Networking subsystem
> requires first line of comment not to be empty:
> WARNING:NETWORKING_BLOCK_COMMENT_STYLE: networking block comments don't use an empty /* line, use /* Comment...
>
>  drivers/net/ethernet/ti/davinci_mdio.c |   21 +++++++++++++++++++--
>  1 file changed, 19 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/ti/davinci_mdio.c b/drivers/net/ethernet/ti/davinci_mdio.c
> index 735dc53..2791f6f 100644
> --- a/drivers/net/ethernet/ti/davinci_mdio.c
> +++ b/drivers/net/ethernet/ti/davinci_mdio.c
> @@ -38,6 +38,7 @@
>  #include <linux/davinci_emac.h>
>  #include <linux/of.h>
>  #include <linux/of_device.h>
> +#include <linux/of_mdio.h>
>  #include <linux/pinctrl/consumer.h>
>
>  /*
> @@ -95,6 +96,10 @@ struct davinci_mdio_data {
>         struct mii_bus  *bus;
>         bool            suspended;
>         unsigned long   access_time; /* jiffies */
> +       /* Indicates that driver shouldn't modify phy_mask in case
> +        * if MDIO bus is registered from DT.
> +        */
> +       bool            skip_scan;
>  };
>
>  static void __davinci_mdio_reset(struct davinci_mdio_data *data)
> @@ -144,6 +149,9 @@ static int davinci_mdio_reset(struct mii_bus *bus)
>         dev_info(data->dev, "davinci mdio revision %d.%d\n",
>                  (ver >> 8) & 0xff, ver & 0xff);
>
> +       if (data->skip_scan)
> +               return 0;
> +
>         /* get phy mask from the alive register */
>         phy_mask = __raw_readl(&data->regs->alive);
>         if (phy_mask) {
> @@ -369,8 +377,17 @@ static int davinci_mdio_probe(struct platform_device *pdev)
>                 goto bail_out;
>         }
>
> -       /* register the mii bus */
> -       ret = mdiobus_register(data->bus);
> +       /* register the mii bus
> +        * Create PHYs from DT only in case if PHY child nodes are explicitly
> +        * defined to support backward compatibility with DTs which assume that
> +        * Davinci MDIO will always scan the bus for PHYs detection.
> +        */
> +       if (dev->of_node && of_get_child_count(dev->of_node)) {
> +               data->skip_scan = true;
> +               ret = of_mdiobus_register(data->bus, dev->of_node);
> +       } else {
> +               ret = mdiobus_register(data->bus);
> +       }
>         if (ret)
>                 goto bail_out;
>
> --
> 1.7.9.5
>