From 842c7da3eee25fe843bb94f05763806e36e1f26c Mon Sep 17 00:00:00 2001
From: Xu Yang <xu.yang_2@nxp.com>
Date: Tue, 27 Jun 2023 19:21:24 +0800
Subject: [PATCH] usb: chipidea: imx: improve logic if samsung,picophy-*
 parameter is 0

commit 36668515d56bf73f06765c71e08c8f7465f1e5c4 upstream.

In current driver, the value of tuning parameter will not take effect
if samsung,picophy-* is assigned as 0. Because 0 is also a valid value
acccording to the description of USB_PHY_CFG1 register, this will improve
the logic to let it work.

Fixes: 58a3cefb3840 ("usb: chipidea: imx: add two samsung picophy parameters tuning implementation")
cc: <stable@vger.kernel.org>
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Acked-by: Peter Chen <peter.chen@kernel.org>
Link: https://lore.kernel.org/r/20230627112126.1882666-1-xu.yang_2@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/usb/chipidea/ci_hdrc_imx.c | 10 ++++++----
 drivers/usb/chipidea/usbmisc_imx.c |  6 ++++--
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/chipidea/ci_hdrc_imx.c b/drivers/usb/chipidea/ci_hdrc_imx.c
index 669e7606651a..d8efa90479e2 100644
--- a/drivers/usb/chipidea/ci_hdrc_imx.c
+++ b/drivers/usb/chipidea/ci_hdrc_imx.c
@@ -175,10 +175,12 @@ 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, "samsung,picophy-pre-emp-curr-control",
-			&data->emp_curr_control);
-	of_property_read_u32(np, "samsung,picophy-dc-vol-level-adjust",
-			&data->dc_vol_level_adjust);
+	if (of_property_read_u32(np, "samsung,picophy-pre-emp-curr-control",
+			&data->emp_curr_control))
+		data->emp_curr_control = -1;
+	if (of_property_read_u32(np, "samsung,picophy-dc-vol-level-adjust",
+			&data->dc_vol_level_adjust))
+		data->dc_vol_level_adjust = -1;
 
 	return data;
 }
diff --git a/drivers/usb/chipidea/usbmisc_imx.c b/drivers/usb/chipidea/usbmisc_imx.c
index 2318c7906acd..a2cb4f48c84c 100644
--- a/drivers/usb/chipidea/usbmisc_imx.c
+++ b/drivers/usb/chipidea/usbmisc_imx.c
@@ -657,13 +657,15 @@ static int usbmisc_imx7d_init(struct imx_usbmisc_data *data)
 			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 <=
+		if (data->emp_curr_control >= 0 &&
+			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 <=
+		if (data->dc_vol_level_adjust >= 0 &&
+			data->dc_vol_level_adjust <=
 			(TXVREFTUNE0_MASK >> TXVREFTUNE0_BIT)) {
 			reg &= ~TXVREFTUNE0_MASK;
 			reg |= (data->dc_vol_level_adjust << TXVREFTUNE0_BIT);