phy: qualcomm: phy-qcom-eusb2-repeater: Add tuning overrides

There are devices in the wild, like the Sony Xperia 1 V that *require*
different tuning than the base design for USB to work.

Add support for overriding the necessary tuning values.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20230830-topic-eusb2_override-v2-4-7d8c893d93f6@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Author: konradybcio

drivers/phy/qualcomm/phy-qcom-eusb2-repeater.c

@@ -142,7 +142,9 @@ static int eusb2_repeater_init(struct phy *phy)
 {
 	struct reg_field *regfields = eusb2_repeater_tune_reg_fields;
 	struct eusb2_repeater *rptr = phy_get_drvdata(phy);
-	const u32 *init_tbl = rptr->cfg->init_tbl;
+	struct device_node *np = rptr->dev->of_node;
+	u32 init_tbl[F_NUM_TUNE_FIELDS] = { 0 };
+	u8 override;
 	u32 val;
 	int ret;
 	int i;
@@ -163,6 +165,19 @@ static int eusb2_repeater_init(struct phy *phy)
 			regmap_field_update_bits(rptr->regs[i], mask, 0);
 		}
 	}
+	memcpy(init_tbl, rptr->cfg->init_tbl, sizeof(init_tbl));
+
+	if (!of_property_read_u8(np, "qcom,tune-usb2-amplitude", &override))
+		init_tbl[F_TUNE_IUSB2] = override;
+
+	if (!of_property_read_u8(np, "qcom,tune-usb2-disc-thres", &override))
+		init_tbl[F_TUNE_HSDISC] = override;
+
+	if (!of_property_read_u8(np, "qcom,tune-usb2-preem", &override))
+		init_tbl[F_TUNE_USB2_PREEM] = override;
+
+	for (i = 0; i < F_NUM_TUNE_FIELDS; i++)
+		regmap_field_update_bits(rptr->regs[i], init_tbl[i], init_tbl[i]);
 
 	ret = regmap_field_read_poll_timeout(rptr->regs[F_RPTR_STATUS],
 					     val, val & RPTR_OK, 10, 5);