[PATCH v2 2/2] phy: fsl-imx8mp-usb: add support for phy tuning
From: Johannes Zink
Date: Tue May 16 2023 - 12:21:26 EST
From: Li Jun <jun.li@xxxxxxx>
Add USB PHY parameter tuning for USB certifications.
Reviewed-by: Haibo Chen <haibo.chen@xxxxxxx>
Signed-off-by: Li Jun <jun.li@xxxxxxx>
[j.zink: ported to v6.3-rc1 from NXP downstream repo + cleanups]
Signed-off-by: Johannes Zink <j.zink@xxxxxxxxxxxxxx>
---
drivers/phy/freescale/phy-fsl-imx8mq-usb.c | 218 +++++++++++++++++++++++++++++
1 file changed, 218 insertions(+)
diff --git a/drivers/phy/freescale/phy-fsl-imx8mq-usb.c b/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
index a29b4a6f7c24..88826ceb72f8 100644
--- a/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
+++ b/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
@@ -27,17 +27,231 @@
#define PHY_CTRL2_TXENABLEN0 BIT(8)
#define PHY_CTRL2_OTG_DISABLE BIT(9)
+#define PHY_CTRL3 0xc
+#define PHY_CTRL3_COMPDISTUNE_MASK GENMASK(2, 0)
+#define PHY_CTRL3_TXPREEMP_TUNE_MASK GENMASK(16, 15)
+#define PHY_CTRL3_TXRISE_TUNE_MASK GENMASK(21, 20)
+#define PHY_CTRL3_TXVREF_TUNE_MASK GENMASK(25, 22)
+#define PHY_CTRL3_TX_VBOOST_LEVEL_MASK GENMASK(31, 29)
+
+#define PHY_CTRL4 0x10
+#define PHY_CTRL4_PCS_TX_DEEMPH_3P5DB_MASK GENMASK(20, 15)
+
+#define PHY_CTRL5 0x14
+#define PHY_CTRL5_DMPWD_OVERRIDE_SEL BIT(23)
+#define PHY_CTRL5_DMPWD_OVERRIDE BIT(22)
+#define PHY_CTRL5_DPPWD_OVERRIDE_SEL BIT(21)
+#define PHY_CTRL5_DPPWD_OVERRIDE BIT(20)
+#define PHY_CTRL5_PCS_TX_SWING_FULL_MASK GENMASK(6, 0)
+
#define PHY_CTRL6 0x18
#define PHY_CTRL6_ALT_CLK_EN BIT(1)
#define PHY_CTRL6_ALT_CLK_SEL BIT(0)
+#define PHY_TUNE_DEFAULT 0xffffffff
+
struct imx8mq_usb_phy {
struct phy *phy;
struct clk *clk;
void __iomem *base;
struct regulator *vbus;
+ u32 pcs_tx_swing_full;
+ u32 pcs_tx_deemph_3p5db;
+ u32 tx_vref_tune;
+ u32 tx_rise_tune;
+ u32 tx_preemp_amp_tune;
+ u32 tx_vboost_level;
+ u32 comp_dis_tune;
};
+static u32 phy_tx_vref_tune_from_property(u32 percent)
+{
+ percent = clamp(percent, 94U, 124U);
+
+ return DIV_ROUND_CLOSEST(percent - 94U, 2);
+}
+
+static u32 phy_tx_rise_tune_from_property(u32 percent)
+{
+ switch (percent) {
+ case 0 ... 98:
+ return 3;
+ case 99:
+ return 2;
+ case 100 ... 101:
+ return 1;
+ default:
+ return 0;
+ }
+}
+
+static u32 phy_tx_preemp_amp_tune_from_property(u32 microamp)
+{
+ microamp = min(microamp, 1800U);
+
+ return microamp / 600;
+}
+
+static u32 phy_tx_vboost_level_from_property(u32 microvolt)
+{
+ switch (microvolt) {
+ case 0 ... 960:
+ return 0;
+ case 961 ... 1160:
+ return 2;
+ default:
+ return 3;
+ }
+}
+
+static u32 phy_pcs_tx_deemph_3p5db_from_property(u32 decibel)
+{
+ return min(decibel, 36U);
+}
+
+static u32 phy_comp_dis_tune_from_property(u32 percent)
+{
+ switch (percent) {
+ case 0 ... 92:
+ return 0;
+ case 93 ... 95:
+ return 1;
+ case 96 ... 97:
+ return 2;
+ case 98 ... 102:
+ return 3;
+ case 103 ... 105:
+ return 4;
+ case 106 ... 109:
+ return 5;
+ case 110 ... 113:
+ return 6;
+ default:
+ return 7;
+ }
+}
+static u32 phy_pcs_tx_swing_full_from_property(u32 percent)
+{
+ percent = min(percent, 100U);
+
+ return (percent * 127) / 100;
+}
+
+static void imx8m_get_phy_tuning_data(struct imx8mq_usb_phy *imx_phy)
+{
+ struct device *dev = imx_phy->phy->dev.parent;
+
+ if (device_property_read_u32(dev, "fsl,phy-tx-vref-tune-percent",
+ &imx_phy->tx_vref_tune))
+ imx_phy->tx_vref_tune = PHY_TUNE_DEFAULT;
+ else
+ imx_phy->tx_vref_tune =
+ phy_tx_vref_tune_from_property(imx_phy->tx_vref_tune);
+
+ if (device_property_read_u32(dev, "fsl,phy-tx-rise-tune-percent",
+ &imx_phy->tx_rise_tune))
+ imx_phy->tx_rise_tune = PHY_TUNE_DEFAULT;
+ else
+ imx_phy->tx_rise_tune =
+ phy_tx_rise_tune_from_property(imx_phy->tx_rise_tune);
+
+ if (device_property_read_u32(dev, "fsl,phy-tx-preemp-amp-tune-microamp",
+ &imx_phy->tx_preemp_amp_tune))
+ imx_phy->tx_preemp_amp_tune = PHY_TUNE_DEFAULT;
+ else
+ imx_phy->tx_preemp_amp_tune =
+ phy_tx_preemp_amp_tune_from_property(imx_phy->tx_preemp_amp_tune);
+
+ if (device_property_read_u32(dev, "fsl,phy-tx-vboost-level-microvolt",
+ &imx_phy->tx_vboost_level))
+ imx_phy->tx_vboost_level = PHY_TUNE_DEFAULT;
+ else
+ imx_phy->tx_vboost_level =
+ phy_tx_vboost_level_from_property(imx_phy->tx_vboost_level);
+
+ if (device_property_read_u32(dev, "fsl,phy-comp-dis-tune-percent",
+ &imx_phy->comp_dis_tune))
+ imx_phy->comp_dis_tune = PHY_TUNE_DEFAULT;
+ else
+ imx_phy->comp_dis_tune =
+ phy_comp_dis_tune_from_property(imx_phy->comp_dis_tune);
+
+ if (device_property_read_u32(dev, "fsl,pcs-tx-deemph-3p5db-attenuation-db",
+ &imx_phy->pcs_tx_deemph_3p5db))
+ imx_phy->pcs_tx_deemph_3p5db = PHY_TUNE_DEFAULT;
+ else
+ imx_phy->pcs_tx_deemph_3p5db =
+ phy_pcs_tx_deemph_3p5db_from_property(imx_phy->pcs_tx_deemph_3p5db);
+
+ if (device_property_read_u32(dev, "fsl,phy-pcs-tx-swing-full-percent",
+ &imx_phy->pcs_tx_swing_full))
+ imx_phy->pcs_tx_swing_full = PHY_TUNE_DEFAULT;
+ else
+ imx_phy->pcs_tx_swing_full =
+ phy_pcs_tx_swing_full_from_property(imx_phy->pcs_tx_swing_full);
+}
+
+static void imx8m_phy_tune(struct imx8mq_usb_phy *imx_phy)
+{
+ u32 value;
+
+ /* PHY tuning */
+ if (imx_phy->pcs_tx_deemph_3p5db != PHY_TUNE_DEFAULT) {
+ value = readl(imx_phy->base + PHY_CTRL4);
+ value &= ~PHY_CTRL4_PCS_TX_DEEMPH_3P5DB_MASK;
+ value |= FIELD_PREP(PHY_CTRL4_PCS_TX_DEEMPH_3P5DB_MASK,
+ imx_phy->pcs_tx_deemph_3p5db);
+ writel(value, imx_phy->base + PHY_CTRL4);
+ }
+
+ if (imx_phy->pcs_tx_swing_full != PHY_TUNE_DEFAULT) {
+ value = readl(imx_phy->base + PHY_CTRL5);
+ value |= FIELD_PREP(PHY_CTRL5_PCS_TX_SWING_FULL_MASK,
+ imx_phy->pcs_tx_swing_full);
+ writel(value, imx_phy->base + PHY_CTRL5);
+ }
+
+ if ((imx_phy->tx_vref_tune & imx_phy->tx_rise_tune &
+ imx_phy->tx_preemp_amp_tune & imx_phy->comp_dis_tune &
+ imx_phy->tx_vboost_level) == PHY_TUNE_DEFAULT)
+ /* If all are the default values, no need update. */
+ return;
+
+ value = readl(imx_phy->base + PHY_CTRL3);
+
+ if (imx_phy->tx_vref_tune != PHY_TUNE_DEFAULT) {
+ value &= ~PHY_CTRL3_TXVREF_TUNE_MASK;
+ value |= FIELD_PREP(PHY_CTRL3_TXVREF_TUNE_MASK,
+ imx_phy->tx_vref_tune);
+ }
+
+ if (imx_phy->tx_rise_tune != PHY_TUNE_DEFAULT) {
+ value &= ~PHY_CTRL3_TXRISE_TUNE_MASK;
+ value |= FIELD_PREP(PHY_CTRL3_TXRISE_TUNE_MASK,
+ imx_phy->tx_rise_tune);
+ }
+
+ if (imx_phy->tx_preemp_amp_tune != PHY_TUNE_DEFAULT) {
+ value &= ~PHY_CTRL3_TXPREEMP_TUNE_MASK;
+ value |= FIELD_PREP(PHY_CTRL3_TXPREEMP_TUNE_MASK,
+ imx_phy->tx_preemp_amp_tune);
+ }
+
+ if (imx_phy->comp_dis_tune != PHY_TUNE_DEFAULT) {
+ value &= ~PHY_CTRL3_COMPDISTUNE_MASK;
+ value |= FIELD_PREP(PHY_CTRL3_COMPDISTUNE_MASK,
+ imx_phy->comp_dis_tune);
+ }
+
+ if (imx_phy->tx_vboost_level != PHY_TUNE_DEFAULT) {
+ value &= ~PHY_CTRL3_TX_VBOOST_LEVEL_MASK;
+ value |= FIELD_PREP(PHY_CTRL3_TX_VBOOST_LEVEL_MASK,
+ imx_phy->tx_vboost_level);
+ }
+
+ writel(value, imx_phy->base + PHY_CTRL3);
+}
+
static int imx8mq_usb_phy_init(struct phy *phy)
{
struct imx8mq_usb_phy *imx_phy = phy_get_drvdata(phy);
@@ -99,6 +313,8 @@ static int imx8mp_usb_phy_init(struct phy *phy)
value &= ~(PHY_CTRL1_RESET | PHY_CTRL1_ATERESET);
writel(value, imx_phy->base + PHY_CTRL1);
+ imx8m_phy_tune(imx_phy);
+
return 0;
}
@@ -182,6 +398,8 @@ static int imx8mq_usb_phy_probe(struct platform_device *pdev)
phy_set_drvdata(imx_phy->phy, imx_phy);
+ imx8m_get_phy_tuning_data(imx_phy);
+
phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
return PTR_ERR_OR_ZERO(phy_provider);
--
2.39.2