[PATCH v12 2/3] phy: qcom-snps: Add support for overriding phy tuning parameters

[Krishna Kurapati <quic_kriskura@quicinc.com>]

Add support for overriding electrical signal tuning parameters for
SNPS HS Phy.

Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
---
 drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c | 252 +++++++++++++++++++++++++-
 1 file changed, 250 insertions(+), 2 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c b/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c
index 5d20378..7a0d01c 100644
--- a/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c
+++ b/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c
@@ -52,6 +52,12 @@
 #define USB2_SUSPEND_N				BIT(2)
 #define USB2_SUSPEND_N_SEL			BIT(3)
 
+#define USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X0		(0x6c)
+#define USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X1		(0x70)
+#define USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X2		(0x74)
+#define USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X3		(0x78)
+#define PARAM_OVRD_MASK				0xFF
+
 #define USB2_PHY_USB_PHY_CFG0			(0x94)
 #define UTMI_PHY_DATAPATH_CTRL_OVERRIDE_EN	BIT(0)
 #define UTMI_PHY_CMN_CTRL_OVERRIDE_EN		BIT(1)
@@ -60,12 +66,47 @@
 #define REFCLK_SEL_MASK				GENMASK(1, 0)
 #define REFCLK_SEL_DEFAULT			(0x2 << 0)
 
+#define HS_DISCONNECT_MASK			GENMASK(2, 0)
+#define SQUELCH_DETECTOR_MASK			GENMASK(7, 5)
+
+#define HS_AMPLITUDE_MASK			GENMASK(3, 0)
+#define PREEMPHASIS_DURATION_MASK		BIT(5)
+#define PREEMPHASIS_AMPLITUDE_MASK		GENMASK(7, 6)
+
+#define HS_RISE_FALL_MASK			GENMASK(1, 0)
+#define HS_CROSSOVER_VOLTAGE_MASK		GENMASK(3, 2)
+#define HS_OUTPUT_IMPEDANCE_MASK		GENMASK(5, 4)
+
+#define LS_FS_OUTPUT_IMPEDANCE_MASK		GENMASK(3, 0)
+
 static const char * const qcom_snps_hsphy_vreg_names[] = {
 	"vdda-pll", "vdda33", "vdda18",
 };
 
 #define SNPS_HS_NUM_VREGS		ARRAY_SIZE(qcom_snps_hsphy_vreg_names)
 
+struct override_param {
+	s32	value;
+	u8	reg_val;
+};
+
+struct override_param_map {
+	const char *prop_name;
+	const struct override_param *param_table;
+	u8 table_size;
+	u8 reg_offset;
+	u8 param_mask;
+};
+
+struct phy_override_seq {
+	bool	need_update;
+	u8	offset;
+	u8	value;
+	u8	mask;
+};
+
+#define NUM_HSPHY_TUNING_PARAMS	(9)
+
 /**
  * struct qcom_snps_hsphy - snps hs phy attributes
  *
@@ -91,6 +132,7 @@ struct qcom_snps_hsphy {
 
 	bool phy_initialized;
 	enum phy_mode mode;
+	struct phy_override_seq update_seq_cfg[NUM_HSPHY_TUNING_PARAMS];
 };
 
 static inline void qcom_snps_hsphy_write_mask(void __iomem *base, u32 offset,
@@ -173,10 +215,158 @@ static int qcom_snps_hsphy_set_mode(struct phy *phy, enum phy_mode mode,
 	return 0;
 }
 
+static const struct override_param hs_disconnect_sc7280[] = {
+	{ -272, 0 },
+	{ 0, 1 },
+	{ 317, 2 },
+	{ 630, 3 },
+	{ 973, 4 },
+	{ 1332, 5 },
+	{ 1743, 6 },
+	{ 2156, 7 },
+};
+
+static const struct override_param squelch_det_threshold_sc7280[] = {
+	{ -2090, 7 },
+	{ -1560, 6 },
+	{ -1030, 5 },
+	{ -530, 4 },
+	{ 0, 3 },
+	{ 530, 2 },
+	{ 1060, 1 },
+	{ 1590, 0 },
+};
+
+static const struct override_param hs_amplitude_sc7280[] = {
+	{ -660, 0 },
+	{ -440, 1 },
+	{ -220, 2 },
+	{ 0, 3 },
+	{ 230, 4 },
+	{ 440, 5 },
+	{ 650, 6 },
+	{ 890, 7 },
+	{ 1110, 8 },
+	{ 1330, 9 },
+	{ 1560, 10 },
+	{ 1780, 11 },
+	{ 2000, 12 },
+	{ 2220, 13 },
+	{ 2430, 14 },
+	{ 2670, 15 },
+};
+
+static const struct override_param preemphasis_duration_sc7280[] = {
+	{ 10000, 1 },
+	{ 20000, 0 },
+};
+
+static const struct override_param preemphasis_amplitude_sc7280[] = {
+	{ 10000, 1 },
+	{ 20000, 2 },
+	{ 30000, 3 },
+	{ 40000, 0 },
+};
+
+static const struct override_param hs_rise_fall_time_sc7280[] = {
+	{ -4100, 3 },
+	{ 0, 2 },
+	{ 2810, 1 },
+	{ 5430, 0 },
+};
+
+static const struct override_param hs_crossover_voltage_sc7280[] = {
+	{ -31000, 1 },
+	{ 0, 3 },
+	{ 28000, 2 },
+};
+
+static const struct override_param hs_output_impedance_sc7280[] = {
+	{ -2300000, 3 },
+	{ 0, 2 },
+	{ 2600000, 1 },
+	{ 6100000, 0 },
+};
+
+static const struct override_param ls_fs_output_impedance_sc7280[] = {
+	{ -1053, 15 },
+	{ -557, 7 },
+	{ 0, 3 },
+	{ 612, 1 },
+	{ 1310, 0 },
+};
+
+static const struct override_param_map sc7280_snps_7nm_phy[] = {
+	{
+		"qcom,hs-disconnect-bp",
+		hs_disconnect_sc7280,
+		ARRAY_SIZE(hs_disconnect_sc7280),
+		USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X0,
+		HS_DISCONNECT_MASK
+	},
+	{
+		"qcom,squelch-detector-bp",
+		squelch_det_threshold_sc7280,
+		ARRAY_SIZE(squelch_det_threshold_sc7280),
+		USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X0,
+		SQUELCH_DETECTOR_MASK
+	},
+	{
+		"qcom,hs-amplitude-bp",
+		hs_amplitude_sc7280,
+		ARRAY_SIZE(hs_amplitude_sc7280),
+		USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X1,
+		HS_AMPLITUDE_MASK
+	},
+	{
+		"qcom,pre-emphasis-duration-bp",
+		preemphasis_duration_sc7280,
+		ARRAY_SIZE(preemphasis_duration_sc7280),
+		USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X1,
+		PREEMPHASIS_DURATION_MASK,
+	},
+	{
+		"qcom,pre-emphasis-amplitude-bp",
+		preemphasis_amplitude_sc7280,
+		ARRAY_SIZE(preemphasis_amplitude_sc7280),
+		USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X1,
+		PREEMPHASIS_AMPLITUDE_MASK,
+	},
+	{
+		"qcom,hs-rise-fall-time-bp",
+		hs_rise_fall_time_sc7280,
+		ARRAY_SIZE(hs_rise_fall_time_sc7280),
+		USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X2,
+		HS_RISE_FALL_MASK
+	},
+	{
+		"qcom,hs-crossover-voltage-microvolt",
+		hs_crossover_voltage_sc7280,
+		ARRAY_SIZE(hs_crossover_voltage_sc7280),
+		USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X2,
+		HS_CROSSOVER_VOLTAGE_MASK
+	},
+	{
+		"qcom,hs-output-impedance-micro-ohms",
+		hs_output_impedance_sc7280,
+		ARRAY_SIZE(hs_output_impedance_sc7280),
+		USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X2,
+		HS_OUTPUT_IMPEDANCE_MASK,
+	},
+	{
+		"qcom,ls-fs-output-impedance-bp",
+		ls_fs_output_impedance_sc7280,
+		ARRAY_SIZE(ls_fs_output_impedance_sc7280),
+		USB2_PHY_USB_PHY_HS_PHY_OVERRIDE_X3,
+		LS_FS_OUTPUT_IMPEDANCE_MASK,
+	},
+	{},
+};
+
 static int qcom_snps_hsphy_init(struct phy *phy)
 {
 	struct qcom_snps_hsphy *hsphy = phy_get_drvdata(phy);
-	int ret;
+	int ret, i;
 
 	dev_vdbg(&phy->dev, "%s(): Initializing SNPS HS phy\n", __func__);
 
@@ -223,6 +413,14 @@ static int qcom_snps_hsphy_init(struct phy *phy)
 	qcom_snps_hsphy_write_mask(hsphy->base, USB2_PHY_USB_PHY_HS_PHY_CTRL1,
 					VBUSVLDEXT0, VBUSVLDEXT0);
 
+	for (i = 0; i < ARRAY_SIZE(hsphy->update_seq_cfg); i++) {
+		if (hsphy->update_seq_cfg[i].need_update)
+			qcom_snps_hsphy_write_mask(hsphy->base,
+					hsphy->update_seq_cfg[i].offset,
+					hsphy->update_seq_cfg[i].mask,
+					hsphy->update_seq_cfg[i].value);
+	}
+
 	qcom_snps_hsphy_write_mask(hsphy->base,
 					USB2_PHY_USB_PHY_HS_PHY_CTRL_COMMON2,
 					VREGBYPASS, VREGBYPASS);
@@ -280,7 +478,10 @@ static const struct phy_ops qcom_snps_hsphy_gen_ops = {
 static const struct of_device_id qcom_snps_hsphy_of_match_table[] = {
 	{ .compatible	= "qcom,sm8150-usb-hs-phy", },
 	{ .compatible	= "qcom,usb-snps-hs-5nm-phy", },
-	{ .compatible	= "qcom,usb-snps-hs-7nm-phy", },
+	{
+		.compatible	= "qcom,usb-snps-hs-7nm-phy",
+		.data		= &sc7280_snps_7nm_phy,
+	},
 	{ .compatible	= "qcom,usb-snps-femto-v2-phy",	},
 	{ }
 };
@@ -291,6 +492,52 @@ static const struct dev_pm_ops qcom_snps_hsphy_pm_ops = {
 			   qcom_snps_hsphy_runtime_resume, NULL)
 };
 
+static void qcom_snps_hsphy_override_param_update_val(
+			const struct override_param_map map,
+			s32 dt_val, struct phy_override_seq *seq_entry)
+{
+	int i;
+
+	/*
+	 * Param table for each param is in increasing order
+	 * of dt values. We need to iterate over the list to
+	 * select the entry that matches the dt value and pick
+	 * up the corresponding register value.
+	 */
+	for (i = 0; i < map.table_size - 1; i++) {
+		if (map.param_table[i].value == dt_val)
+			break;
+	}
+
+	seq_entry->need_update = true;
+	seq_entry->offset = map.reg_offset;
+	seq_entry->mask = map.param_mask;
+	seq_entry->value = map.param_table[i].reg_val << __ffs(map.param_mask);
+}
+
+static void qcom_snps_hsphy_read_override_param_seq(struct device *dev)
+{
+	struct device_node *node = dev->of_node;
+	s32 val;
+	int ret, i;
+	struct qcom_snps_hsphy *hsphy;
+	const struct override_param_map *cfg = of_device_get_match_data(dev);
+
+	hsphy = dev_get_drvdata(dev);
+
+	for (i = 0; cfg[i].prop_name != NULL; i++) {
+		ret = of_property_read_s32(node, cfg[i].prop_name, &val);
+		if (ret)
+			continue;
+
+		qcom_snps_hsphy_override_param_update_val(cfg[i], val,
+					&hsphy->update_seq_cfg[i]);
+		dev_dbg(&hsphy->phy->dev, "Read param: %s dt_val: %d reg_val: 0x%x\n",
+			cfg[i].prop_name, val, hsphy->update_seq_cfg[i].value);
+
+	}
+}
+
 static int qcom_snps_hsphy_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -352,6 +599,7 @@ static int qcom_snps_hsphy_probe(struct platform_device *pdev)
 
 	dev_set_drvdata(dev, hsphy);
 	phy_set_drvdata(generic_phy, hsphy);
+	qcom_snps_hsphy_read_override_param_seq(dev);
 
 	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
 	if (!IS_ERR(phy_provider))
-- 
2.7.4