On 25.03.2020 16:03, Philippe Schenker wrote:
> The KSZ9131 provides DLL controlled delays on RXC and TXC lines. This
> patch makes use of those delays. The information which delays should
> be enabled or disabled comes from the interface names, documented in
> ethernet-controller.yaml:
>
> rgmii: Disable RXC and TXC delays
> rgmii-id: Enable RXC and TXC delays
> rgmii-txid: Enable only TXC delay, disable RXC delay
> rgmii-rxid: Enable onlx RXC delay, disable TXC delay
>
> Signed-off-by: Philippe Schenker <philippe.schenker@xxxxxxxxxxx>
> ---
>
> drivers/net/phy/micrel.c | 45 ++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 45 insertions(+)
>
> diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
> index 63dedec0433d..d3ad09774847 100644
> --- a/drivers/net/phy/micrel.c
> +++ b/drivers/net/phy/micrel.c
> @@ -704,6 +704,48 @@ static int ksz9131_of_load_skew_values(struct phy_device *phydev,
> return phy_write_mmd(phydev, 2, reg, newval);
> }
>
> +/* MMD Address 0x2 */
> +#define KSZ9131RN_RXC_DLL_CTRL 76
> +#define KSZ9131RN_TXC_DLL_CTRL 77
> +#define KSZ9131RN_DLL_CTRL_BYPASS BIT_MASK(12)
> +#define KSZ9131RN_DLL_ENABLE_DELAY 0
> +#define KSZ9131RN_DLL_DISABLE_DELAY BIT(12)
> +
> +static int ksz9131_config_rgmii_delay(struct phy_device *phydev)
> +{
> + int ret;
> + u16 rxcdll_val, txcdll_val;
> +
Reverse xmas tree order please.
> + switch (phydev->interface) {
> + case PHY_INTERFACE_MODE_RGMII:
> + rxcdll_val = KSZ9131RN_DLL_DISABLE_DELAY;
> + txcdll_val = KSZ9131RN_DLL_DISABLE_DELAY;
> + break;
> + case PHY_INTERFACE_MODE_RGMII_ID:
> + rxcdll_val = KSZ9131RN_DLL_ENABLE_DELAY;
> + txcdll_val = KSZ9131RN_DLL_ENABLE_DELAY;
> + break;
> + case PHY_INTERFACE_MODE_RGMII_RXID:
> + rxcdll_val = KSZ9131RN_DLL_ENABLE_DELAY;
> + txcdll_val = KSZ9131RN_DLL_DISABLE_DELAY;
> + break;
> + case PHY_INTERFACE_MODE_RGMII_TXID:
> + rxcdll_val = KSZ9131RN_DLL_DISABLE_DELAY;
> + txcdll_val = KSZ9131RN_DLL_ENABLE_DELAY;
> + break;
> + default:
> + return 0;
> + }
> +
> + ret = phy_modify_mmd_changed(phydev, 2, KSZ9131RN_RXC_DLL_CTRL,
> + KSZ9131RN_DLL_CTRL_BYPASS, rxcdll_val);
> + if (ret < 0)
> + return ret;
> +
> + return phy_modify_mmd_changed(phydev, 2, KSZ9131RN_TXC_DLL_CTRL,
> + KSZ9131RN_DLL_CTRL_BYPASS, txcdll_val);
phy_modify_mmd_changed() returns 1 if the register value was changed,
and that's not what you want here. Simply use phy_modify_mmd() in both
occurrences. And your function has a return value, but it's not used by
the caller.
> +}
> +
> static int ksz9131_config_init(struct phy_device *phydev)
> {
> const struct device *dev = &phydev->mdio.dev;
> @@ -730,6 +772,9 @@ static int ksz9131_config_init(struct phy_device *phydev)
> if (!of_node)
> return 0;
>
> + if (phy_interface_is_rgmii(phydev))
> + ksz9131_config_rgmii_delay(phydev);
> +
> ret = ksz9131_of_load_skew_values(phydev, of_node,
> MII_KSZ9031RN_CLK_PAD_SKEW, 5,
> clk_skews, 2);
>
