Re: [PATCH v3 3/3] phy: phy-mtk-tphy: add support mt8195

[Vinod Koul]

On 15-07-21, 14:48, Chunfeng Yun wrote:
> The controller is designed to use use PLL integer mode, but
> in fact used fractional mode for some ones on mt8195, this
> causes signal degradation (e.g. eye diagram test fail), fix
> it by switching PLL to 26Mhz from default 48Mhz to improve
> signal quality.
> 
> Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
> ---
> v2~3: no changes
> ---
>  drivers/phy/mediatek/phy-mtk-tphy.c | 52 +++++++++++++++++++++++++++++
>  1 file changed, 52 insertions(+)
> 
> diff --git a/drivers/phy/mediatek/phy-mtk-tphy.c b/drivers/phy/mediatek/phy-mtk-tphy.c
> index 42a1174da6cc..c3dc1763a7eb 100644
> --- a/drivers/phy/mediatek/phy-mtk-tphy.c
> +++ b/drivers/phy/mediatek/phy-mtk-tphy.c
> @@ -41,6 +41,8 @@
>  
>  #define U3P_USBPHYACR0		0x000
>  #define PA0_RG_U2PLL_FORCE_ON		BIT(15)
> +#define PA0_USB20_PLL_PREDIV		GENMASK(7, 6)
> +#define PA0_USB20_PLL_PREDIV_VAL(x)	((0x3 & (x)) << 6)
>  #define PA0_RG_USB20_INTR_EN		BIT(5)
>  
>  #define U3P_USBPHYACR1		0x004
> @@ -52,6 +54,8 @@
>  #define PA1_RG_TERM_SEL_VAL(x)	((0x7 & (x)) << 8)
>  
>  #define U3P_USBPHYACR2		0x008
> +#define PA2_RG_U2PLL_BW			GENMASK(21, 19)
> +#define PA2_RG_U2PLL_BW_VAL(x)		((0x7 & (x)) << 19)
>  #define PA2_RG_SIF_U2PLL_FORCE_EN	BIT(18)
>  
>  #define U3P_USBPHYACR5		0x014
> @@ -73,6 +77,14 @@
>  #define P2C_USB20_GPIO_MODE		BIT(8)
>  #define P2C_U2_GPIO_CTR_MSK	(P2C_RG_USB20_GPIO_CTL | P2C_USB20_GPIO_MODE)
>  
> +#define U3P_U2PHYA_RESV		0x030
> +#define P2R_RG_U2PLL_FBDIV_26M		0x1bb13b
> +#define P2R_RG_U2PLL_FBDIV_48M		0x3c0000
> +
> +#define U3P_U2PHYA_RESV1	0x044
> +#define P2R_RG_U2PLL_REFCLK_SEL	BIT(5)
> +#define P2R_RG_U2PLL_FRA_EN		BIT(3)
> +
>  #define U3D_U2PHYDCR0		0x060
>  #define P2C_RG_SIF_U2PLL_FORCE_ON	BIT(24)
>  
> @@ -277,6 +289,12 @@ enum mtk_phy_version {
>  struct mtk_phy_pdata {
>  	/* avoid RX sensitivity level degradation only for mt8173 */
>  	bool avoid_rx_sen_degradation;
> +	/*
> +	 * u2phy should use integer mode instead of fractional mode of
> +	 * 48M PLL, fix it by switching PLL to 26M from default 48M
> +	 * for mt8195
> +	 */
> +	bool sw_pll_48m_to_26m;
>  	enum mtk_phy_version version;
>  };
>  
> @@ -456,6 +474,33 @@ static void u3_phy_instance_init(struct mtk_tphy *tphy,
>  	dev_dbg(tphy->dev, "%s(%d)\n", __func__, instance->index);
>  }
>  
> +static void u2_phy_pll_26m_set(struct mtk_tphy *tphy,
> +	struct mtk_phy_instance *instance)
> +{
> +	struct u2phy_banks *u2_banks = &instance->u2_banks;
> +	void __iomem *com = u2_banks->com;
> +	u32 tmp;
> +
> +	if (!tphy->pdata->sw_pll_48m_to_26m)
> +		return;
> +
> +	tmp = readl(com + U3P_USBPHYACR0);
> +	tmp &= ~PA0_USB20_PLL_PREDIV;
> +	tmp |= PA0_USB20_PLL_PREDIV_VAL(0);
> +	writel(tmp, com + U3P_USBPHYACR0);
> +
> +	tmp = readl(com + U3P_USBPHYACR2);
> +	tmp &= ~PA2_RG_U2PLL_BW;
> +	tmp |= PA2_RG_U2PLL_BW_VAL(3);
> +	writel(tmp, com + U3P_USBPHYACR2);
> +
> +	writel(P2R_RG_U2PLL_FBDIV_26M, com + U3P_U2PHYA_RESV);
> +
> +	tmp = readl(com + U3P_U2PHYA_RESV1);
> +	tmp |= P2R_RG_U2PLL_FRA_EN | P2R_RG_U2PLL_REFCLK_SEL;
> +	writel(tmp, com + U3P_U2PHYA_RESV1);
> +}
> +
>  static void u2_phy_instance_init(struct mtk_tphy *tphy,
>  	struct mtk_phy_instance *instance)
>  {
> @@ -941,6 +986,7 @@ static int mtk_phy_init(struct phy *phy)
>  
>  	switch (instance->type) {
>  	case PHY_TYPE_USB2:
> +		u2_phy_pll_26m_set(tphy, instance);

should this not be set only for MTK_PHY_V3?

>  		u2_phy_instance_init(tphy, instance);
>  		u2_phy_props_set(tphy, instance);
>  		break;
> @@ -1094,10 +1140,16 @@ static const struct mtk_phy_pdata mt8173_pdata = {
>  	.version = MTK_PHY_V1,
>  };
>  
> +static const struct mtk_phy_pdata mt8195_pdata = {
> +	.sw_pll_48m_to_26m = true,
> +	.version = MTK_PHY_V3,
> +};
> +
>  static const struct of_device_id mtk_tphy_id_table[] = {
>  	{ .compatible = "mediatek,mt2701-u3phy", .data = &tphy_v1_pdata },
>  	{ .compatible = "mediatek,mt2712-u3phy", .data = &tphy_v2_pdata },
>  	{ .compatible = "mediatek,mt8173-u3phy", .data = &mt8173_pdata },
> +	{ .compatible = "mediatek,mt8195-tphy", .data = &mt8195_pdata },
>  	{ .compatible = "mediatek,generic-tphy-v1", .data = &tphy_v1_pdata },
>  	{ .compatible = "mediatek,generic-tphy-v2", .data = &tphy_v2_pdata },
>  	{ .compatible = "mediatek,generic-tphy-v3", .data = &tphy_v3_pdata },
> -- 
> 2.18.0

-- 
~Vinod