[PATCH 2/4] usb: chipidea: imx: add two picophy parameters tuning implementation

[Peter Chen <peter.chen@xxxxxxx>]

These two parameters are used to improve USB signal for board level,
in this commit, we read it from the dtb, and write to related register
during the initialization.

Signed-off-by: Peter Chen <peter.chen@xxxxxxx>
---
 drivers/usb/chipidea/ci_hdrc_imx.c |  5 +++++
 drivers/usb/chipidea/ci_hdrc_imx.h |  2 ++
 drivers/usb/chipidea/usbmisc_imx.c | 21 +++++++++++++++++++++
 3 files changed, 28 insertions(+)

diff --git a/drivers/usb/chipidea/ci_hdrc_imx.c b/drivers/usb/chipidea/ci_hdrc_imx.c
index 5ae16368a0c7..58de0f3ac0e9 100644
--- a/drivers/usb/chipidea/ci_hdrc_imx.c
+++ b/drivers/usb/chipidea/ci_hdrc_imx.c
@@ -165,6 +165,11 @@ static struct imx_usbmisc_data *usbmisc_get_init_data(struct device *dev)
 	if (of_usb_get_phy_mode(np) == USBPHY_INTERFACE_MODE_ULPI)
 		data->ulpi = 1;
 
+	of_property_read_u32(np, "picophy,pre-emp-curr-control",
+			&data->emp_curr_control);
+	of_property_read_u32(np, "picophy,dc-vol-level-adjust",
+			&data->dc_vol_level_adjust);
+
 	return data;
 }
 
diff --git a/drivers/usb/chipidea/ci_hdrc_imx.h b/drivers/usb/chipidea/ci_hdrc_imx.h
index 727d02b6dbd3..367bb0d0cb6b 100644
--- a/drivers/usb/chipidea/ci_hdrc_imx.h
+++ b/drivers/usb/chipidea/ci_hdrc_imx.h
@@ -25,6 +25,8 @@ struct imx_usbmisc_data {
 	unsigned int ext_id:1; /* ID from exteranl event */
 	unsigned int ext_vbus:1; /* Vbus from exteranl event */
 	struct usb_phy *usb_phy;
+	int emp_curr_control;
+	int dc_vol_level_adjust;
 };
 
 int imx_usbmisc_init(struct imx_usbmisc_data *data);
diff --git a/drivers/usb/chipidea/usbmisc_imx.c b/drivers/usb/chipidea/usbmisc_imx.c
index f136876cb4a3..f9881aed468f 100644
--- a/drivers/usb/chipidea/usbmisc_imx.c
+++ b/drivers/usb/chipidea/usbmisc_imx.c
@@ -128,6 +128,12 @@
 #define MX7D_USB_OTG_PHY_STATUS_VBUS_VLD	BIT(3)
 #define MX7D_USB_OTG_PHY_STATUS_CHRGDET		BIT(29)
 
+#define MX7D_USB_OTG_PHY_CFG1		0x30
+#define TXPREEMPAMPTUNE0_BIT		28
+#define TXPREEMPAMPTUNE0_MASK		(3 << 28)
+#define TXVREFTUNE0_BIT			20
+#define TXVREFTUNE0_MASK		(0xf << 20)
+
 #define MX6_USB_OTG_WAKEUP_BITS (MX6_BM_WAKEUP_ENABLE | MX6_BM_VBUS_WAKEUP | \
 				 MX6_BM_ID_WAKEUP)
 
@@ -649,6 +655,21 @@ static int usbmisc_imx7d_init(struct imx_usbmisc_data *data)
 		writel(reg | MX7D_USB_VBUS_WAKEUP_SOURCE_BVALID
 			| MX7D_USBNC_AUTO_RESUME,
 			usbmisc->base + MX7D_USBNC_USB_CTRL2);
+		/* PHY tuning for signal quality */
+		reg = readl(usbmisc->base + MX7D_USB_OTG_PHY_CFG1);
+		if (data->emp_curr_control && data->emp_curr_control <=
+			(TXPREEMPAMPTUNE0_MASK >> TXPREEMPAMPTUNE0_BIT)) {
+			reg &= ~TXPREEMPAMPTUNE0_MASK;
+			reg |= (data->emp_curr_control << TXPREEMPAMPTUNE0_BIT);
+		}
+
+		if (data->dc_vol_level_adjust && data->dc_vol_level_adjust <=
+			(TXVREFTUNE0_MASK >> TXVREFTUNE0_BIT)) {
+			reg &= ~TXVREFTUNE0_MASK;
+			reg |= (data->dc_vol_level_adjust << TXVREFTUNE0_BIT);
+		}
+
+		writel(reg, usbmisc->base + MX7D_USB_OTG_PHY_CFG1);
 	}
 
 	spin_unlock_irqrestore(&usbmisc->lock, flags);
-- 
2.17.1