Re: [PATCH v2 2/2] net: phy: motorcomm: Add pad drive strength cfg support
From: Frank Sae
Date: Fri May 05 2023 - 21:30:30 EST
On 2023/5/5 17:05, Samin Guo wrote:
> The motorcomm phy (YT8531) supports the ability to adjust the drive
> strength of the rx_clk/rx_data, and the default strength may not be
> suitable for all boards. So add configurable options to better match
> the boards.(e.g. StarFive VisionFive 2)
>
> Signed-off-by: Samin Guo <samin.guo@xxxxxxxxxxxxxxxx>
> ---
> drivers/net/phy/motorcomm.c | 46 +++++++++++++++++++++++++++++++++++++
> 1 file changed, 46 insertions(+)
>
> diff --git a/drivers/net/phy/motorcomm.c b/drivers/net/phy/motorcomm.c
> index 2fa5a90e073b..191650bb1454 100644
> --- a/drivers/net/phy/motorcomm.c
> +++ b/drivers/net/phy/motorcomm.c
> @@ -236,6 +236,7 @@
> */
> #define YTPHY_WCR_TYPE_PULSE BIT(0)
>
> +#define YTPHY_PAD_DRIVE_STRENGTH_REG 0xA010
> #define YTPHY_SYNCE_CFG_REG 0xA012
> #define YT8521_SCR_SYNCE_ENABLE BIT(5)
> /* 1b0 output 25m clock
> @@ -260,6 +261,14 @@
> #define YT8531_SCR_CLK_SRC_REF_25M 4
> #define YT8531_SCR_CLK_SRC_SSC_25M 5
>
> +#define YT8531_RGMII_RXC_DS_DEFAULT 0x3
> +#define YT8531_RGMII_RXC_DS_MAX 0x7
> +#define YT8531_RGMII_RXC_DS GENMASK(15, 13)
> +#define YT8531_RGMII_RXD_DS_DEFAULT 0x3
> +#define YT8531_RGMII_RXD_DS_MAX 0x7
> +#define YT8531_RGMII_RXD_DS_LOW GENMASK(5, 4) /* Bit 1/0 of rxd_ds */
> +#define YT8531_RGMII_RXD_DS_HI BIT(12) /* Bit 2 of rxd_ds */
YT8531_RGMII_xxx is bit define for YTPHY_PAD_DRIVE_STRENGTH_REG, so it is better to put it under the define of YTPHY_PAD_DRIVE_STRENGTH_REG.
YT8531_RGMII_xxx bit define as reverse order:
#define YTPHY_PAD_DRIVE_STRENGTH_REG 0xA010
#define YT8531_RGMII_RXC_DS GENMASK(15, 13)
#define YT8531_RGMII_RXD_DS_HI BIT(12) /* Bit 2 of rxd_ds */ <-------
#define YT8531_RGMII_RXD_DS_LOW GENMASK(5, 4) /* Bit 1/0 of rxd_ds */
...
> +
> /* Extended Register end */
>
> #define YTPHY_DTS_OUTPUT_CLK_DIS 0
> @@ -1495,6 +1504,7 @@ static int yt8531_config_init(struct phy_device *phydev)
> {
> struct device_node *node = phydev->mdio.dev.of_node;
> int ret;
> + u32 ds, val;
>
> ret = ytphy_rgmii_clk_delay_config_with_lock(phydev);
> if (ret < 0)
> @@ -1518,6 +1528,42 @@ static int yt8531_config_init(struct phy_device *phydev)
> return ret;
> }
>
> + ds = YT8531_RGMII_RXC_DS_DEFAULT;
> + if (!of_property_read_u32(node, "motorcomm,rx-clk-driver-strength", &val)) {
> + if (val > YT8531_RGMII_RXC_DS_MAX)
> + return -EINVAL;
> +
> + ds = val;
> + }
> +
> + ret = ytphy_modify_ext_with_lock(phydev,
> + YTPHY_PAD_DRIVE_STRENGTH_REG,
> + YT8531_RGMII_RXC_DS,
> + FIELD_PREP(YT8531_RGMII_RXC_DS, ds));
> + if (ret < 0)
> + return ret;
> +
> + ds = FIELD_PREP(YT8531_RGMII_RXD_DS_LOW, YT8531_RGMII_RXD_DS_DEFAULT);
> + if (!of_property_read_u32(node, "motorcomm,rx-data-driver-strength", &val)) {
> + if (val > YT8531_RGMII_RXD_DS_MAX)
> + return -EINVAL;
> +
> + if (val > FIELD_MAX(YT8531_RGMII_RXD_DS_LOW)) {
> + ds = val & FIELD_MAX(YT8531_RGMII_RXD_DS_LOW);
> + ds = FIELD_PREP(YT8531_RGMII_RXD_DS_LOW, ds);
> + ds |= YT8531_RGMII_RXD_DS_HI;
> + } else {
> + ds = FIELD_PREP(YT8531_RGMII_RXD_DS_LOW, val);
> + }
> + }
> +
> + ret = ytphy_modify_ext_with_lock(phydev,
> + YTPHY_PAD_DRIVE_STRENGTH_REG,
> + YT8531_RGMII_RXD_DS_LOW | YT8531_RGMII_RXD_DS_HI,
> + ds);
> + if (ret < 0)
> + return ret;
> +
> return 0;
> }
>