[PATCH for-4.14.y 2/5] phy: phy-mtk-tphy: use auto instead of force to bypass utmi signals

[Amit Pundir <amit.pundir@linaro.org>]

From: Chunfeng Yun <chunfeng.yun@mediatek.com>

commit 00c0092c5f62147b7d85f0c6f1cf245a0a1ff3b6 upstream.

When system is running, if usb2 phy is forced to bypass utmi signals,
all PLL will be turned off, and it can't detect device connection
anymore, so replace force mode with auto mode which can bypass utmi
signals automatically if no device attached for normal flow.
But keep the force mode to fix RX sensitivity degradation issue.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
---
Cherry-picked from lede tree https://git.lede-project.org/?p=source.git
Not applicable for 4.9.y, 4.4.y and 3.18.y

 drivers/phy/mediatek/phy-mtk-tphy.c | 19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)

diff --git a/drivers/phy/mediatek/phy-mtk-tphy.c b/drivers/phy/mediatek/phy-mtk-tphy.c
index 721a2a1c97ef..a63bba12aee4 100644
--- a/drivers/phy/mediatek/phy-mtk-tphy.c
+++ b/drivers/phy/mediatek/phy-mtk-tphy.c
@@ -438,9 +438,9 @@ static void u2_phy_instance_init(struct mtk_tphy *tphy,
 	u32 index = instance->index;
 	u32 tmp;
 
-	/* switch to USB function. (system register, force ip into usb mode) */
+	/* switch to USB function, and enable usb pll */
 	tmp = readl(com + U3P_U2PHYDTM0);
-	tmp &= ~P2C_FORCE_UART_EN;
+	tmp &= ~(P2C_FORCE_UART_EN | P2C_FORCE_SUSPENDM);
 	tmp |= P2C_RG_XCVRSEL_VAL(1) | P2C_RG_DATAIN_VAL(0);
 	writel(tmp, com + U3P_U2PHYDTM0);
 
@@ -500,10 +500,8 @@ static void u2_phy_instance_power_on(struct mtk_tphy *tphy,
 	u32 index = instance->index;
 	u32 tmp;
 
-	/* (force_suspendm=0) (let suspendm=1, enable usb 480MHz pll) */
 	tmp = readl(com + U3P_U2PHYDTM0);
-	tmp &= ~(P2C_FORCE_SUSPENDM | P2C_RG_XCVRSEL);
-	tmp &= ~(P2C_RG_DATAIN | P2C_DTM0_PART_MASK);
+	tmp &= ~(P2C_RG_XCVRSEL | P2C_RG_DATAIN | P2C_DTM0_PART_MASK);
 	writel(tmp, com + U3P_U2PHYDTM0);
 
 	/* OTG Enable */
@@ -538,7 +536,6 @@ static void u2_phy_instance_power_off(struct mtk_tphy *tphy,
 
 	tmp = readl(com + U3P_U2PHYDTM0);
 	tmp &= ~(P2C_RG_XCVRSEL | P2C_RG_DATAIN);
-	tmp |= P2C_FORCE_SUSPENDM;
 	writel(tmp, com + U3P_U2PHYDTM0);
 
 	/* OTG Disable */
@@ -546,18 +543,16 @@ static void u2_phy_instance_power_off(struct mtk_tphy *tphy,
 	tmp &= ~PA6_RG_U2_OTG_VBUSCMP_EN;
 	writel(tmp, com + U3P_USBPHYACR6);
 
-	/* let suspendm=0, set utmi into analog power down */
-	tmp = readl(com + U3P_U2PHYDTM0);
-	tmp &= ~P2C_RG_SUSPENDM;
-	writel(tmp, com + U3P_U2PHYDTM0);
-	udelay(1);
-
 	tmp = readl(com + U3P_U2PHYDTM1);
 	tmp &= ~(P2C_RG_VBUSVALID | P2C_RG_AVALID);
 	tmp |= P2C_RG_SESSEND;
 	writel(tmp, com + U3P_U2PHYDTM1);
 
 	if (tphy->pdata->avoid_rx_sen_degradation && index) {
+		tmp = readl(com + U3P_U2PHYDTM0);
+		tmp &= ~(P2C_RG_SUSPENDM | P2C_FORCE_SUSPENDM);
+		writel(tmp, com + U3P_U2PHYDTM0);
+
 		tmp = readl(com + U3D_U2PHYDCR0);
 		tmp &= ~P2C_RG_SIF_U2PLL_FORCE_ON;
 		writel(tmp, com + U3D_U2PHYDCR0);
-- 
2.7.4