[PATCH v2 1/6] net: eth-phy: add support of device tree configuration for gpio reset

[Ramon Fried]

On Mon, Apr 26, 2021 at 6:47 PM Patrick Delaunay
<patrick.delaunay at foss.st.com> wrote:
>
> The gpio reset and the assert or deassert delay are defined in generic
> binding of the ethernet phy in Linux:
> Documentation/devicetree/bindings/net/ethernet-phy.yaml
>
>   reset-gpios:
>     maxItems: 1
>     description:
>       The GPIO phandle and specifier for the PHY reset signal.
>
>   reset-assert-us:
>     description:
>       Delay after the reset was asserted in microseconds. If this
>       property is missing the delay will be skipped.
>
>   reset-deassert-us:
>     description:
>       Delay after the reset was deasserted in microseconds. If
>       this property is missing the delay will be skipped.
>
> See also U-Boot: doc/device-tree-bindings/net/phy.txt
>
> This patch adds the parsing of this common DT properties in the
> u-class "eth_phy_generic", used by default in the associated driver
> "eth_phy_generic_drv"
>
> This parsing function eth_phy_of_to_plat can be reused by other
> ethernet phy drivers for this uclass UCLASS_ETH_PHY.
>
> Signed-off-by: Patrick Delaunay <patrick.delaunay at foss.st.com>
> ---
>
> Changes in v2:
> - Update eth-phy driver (NEW)
>
>  drivers/net/eth-phy-uclass.c | 50 ++++++++++++++++++++++++++++++++++++
>  1 file changed, 50 insertions(+)
>
> diff --git a/drivers/net/eth-phy-uclass.c b/drivers/net/eth-phy-uclass.c
> index 07aebd935e..153f6909eb 100644
> --- a/drivers/net/eth-phy-uclass.c
> +++ b/drivers/net/eth-phy-uclass.c
> @@ -6,12 +6,17 @@
>  #include <common.h>
>  #include <dm.h>
>  #include <net.h>
> +#include <asm-generic/gpio.h>
>  #include <dm/device-internal.h>
>  #include <dm/uclass-internal.h>
>  #include <dm/lists.h>
> +#include <linux/delay.h>
>
>  struct eth_phy_device_priv {
>         struct mii_dev *mdio_bus;
> +       struct gpio_desc reset_gpio;
> +       u32 reset_assert_delay;
> +       u32 reset_deassert_delay;
>  };
>
>  int eth_phy_binds_nodes(struct udevice *eth_dev)
> @@ -110,13 +115,58 @@ int eth_phy_get_addr(struct udevice *dev)
>         return reg;
>  }
>
> +/* parsing generic properties of devicetree/bindings/net/ethernet-phy.yaml */
> +static int eth_phy_of_to_plat(struct udevice *dev)
> +{
> +       struct eth_phy_device_priv *uc_priv = dev_get_uclass_priv(dev);
> +       int ret;
> +
> +       /* search "reset-gpios" in phy node */
> +       ret = gpio_request_by_name(dev, "reset-gpios", 0,
> +                                  &uc_priv->reset_gpio,
> +                                  GPIOD_IS_OUT);
> +       if (ret != -ENOENT)
> +               return ret;
> +
> +       uc_priv->reset_assert_delay = dev_read_u32_default(dev, "reset-assert-us", 0);
> +       uc_priv->reset_deassert_delay = dev_read_u32_default(dev, "reset-deassert-us", 0);
> +
> +       return 0;
> +}
> +
> +void eth_phy_reset(struct udevice *dev, int value)
> +{
> +       struct eth_phy_device_priv *uc_priv = dev_get_uclass_priv(dev);
> +       u32 delay;
> +
> +       if (!dm_gpio_is_valid(&uc_priv->reset_gpio))
> +               return;
> +
> +       dm_gpio_set_value(&uc_priv->reset_gpio, value);
> +
> +       delay = value ? uc_priv->reset_assert_delay : uc_priv->reset_deassert_delay;
> +       if (delay)
> +               udelay(delay);
> +}
> +
> +static int eth_phy_pre_probe(struct udevice *dev)
> +{
> +       /* Assert and deassert the reset signal */
> +       eth_phy_reset(dev, 1);
> +       eth_phy_reset(dev, 0);
> +
> +       return 0;
> +}
> +
>  UCLASS_DRIVER(eth_phy_generic) = {
>         .id             = UCLASS_ETH_PHY,
>         .name           = "eth_phy_generic",
>         .per_device_auto        = sizeof(struct eth_phy_device_priv),
> +       .pre_probe      = eth_phy_pre_probe,
>  };
>
>  U_BOOT_DRIVER(eth_phy_generic_drv) = {
>         .name           = "eth_phy_generic_drv",
>         .id             = UCLASS_ETH_PHY,
> +       .of_to_plat     = eth_phy_of_to_plat,
>  };
> --
> 2.17.1
>
Reviewed-by: Ramon Fried <rfried.dev at gmail.com>