usb: dwc2: New bitfield definition and programming in GRSTCTL

Added new bitfield GRSTCTL_CLOCK_SWITH_TIMER in GRSTCTL register.
This bitfield applicable HSOTG cores v5.00 or higher and not
applicable to HS/FS IOT devices.
This bitfield must be programmed to 3'b010 if core will be
used in Low-speed and core configured for any HS/FS PHY interface.
This bitfield must be programmed to 3'b111 if core configured
to use either:
- HS PHY interface UTMI or ULPI
- FS PHY any interface

Signed-off-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
Link: https://lore.kernel.org/r/0616838cfee958774c9321c6eeeda4be92f900d8.1708948356.git.Minas.Harutyunyan@synopsys.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 48 insertions, 0 deletions

diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c
index b7a76eb089c9..9919ab725d54 100644
--- a/drivers/usb/dwc2/core.c
+++ b/drivers/usb/dwc2/core.c
@@ -980,6 +980,41 @@ void dwc2_init_fs_ls_pclk_sel(struct dwc2_hsotg *hsotg)
 	dwc2_writel(hsotg, hcfg, HCFG);
 }
 
+static void dwc2_set_clock_switch_timer(struct dwc2_hsotg *hsotg)
+{
+	u32 grstctl, gsnpsid, val = 0;
+
+	gsnpsid = dwc2_readl(hsotg, GSNPSID);
+
+	/*
+	 * Applicable only to HSOTG core v5.00a or higher.
+	 * Not applicable to HS/FS IOT devices.
+	 */
+	if ((gsnpsid & ~DWC2_CORE_REV_MASK) != DWC2_OTG_ID ||
+	    gsnpsid < DWC2_CORE_REV_5_00a)
+		return;
+
+	if ((hsotg->hw_params.hs_phy_type == GHWCFG2_HS_PHY_TYPE_UTMI &&
+	     hsotg->hw_params.fs_phy_type == GHWCFG2_FS_PHY_TYPE_NOT_SUPPORTED) ||
+	    (hsotg->hw_params.hs_phy_type == GHWCFG2_HS_PHY_TYPE_ULPI &&
+	     hsotg->hw_params.fs_phy_type == GHWCFG2_FS_PHY_TYPE_NOT_SUPPORTED) ||
+	    (hsotg->hw_params.hs_phy_type == GHWCFG2_HS_PHY_TYPE_NOT_SUPPORTED &&
+	     hsotg->hw_params.fs_phy_type != GHWCFG2_FS_PHY_TYPE_NOT_SUPPORTED)) {
+		val = GRSTCTL_CLOCK_SWITH_TIMER_VALUE_DIS;
+	}
+
+	if (hsotg->params.speed == DWC2_SPEED_PARAM_LOW &&
+	    hsotg->hw_params.hs_phy_type != GHWCFG2_HS_PHY_TYPE_NOT_SUPPORTED &&
+	    hsotg->hw_params.fs_phy_type != GHWCFG2_FS_PHY_TYPE_NOT_SUPPORTED) {
+		val = GRSTCTL_CLOCK_SWITH_TIMER_VALUE_147;
+	}
+
+	grstctl = dwc2_readl(hsotg, GRSTCTL);
+	grstctl &= ~GRSTCTL_CLOCK_SWITH_TIMER_MASK;
+	grstctl |= GRSTCTL_CLOCK_SWITH_TIMER(val);
+	dwc2_writel(hsotg, grstctl, GRSTCTL);
+}
+
 static int dwc2_fs_phy_init(struct dwc2_hsotg *hsotg, bool select_phy)
 {
 	u32 usbcfg, ggpio, i2cctl;
@@ -997,6 +1032,8 @@ static int dwc2_fs_phy_init(struct dwc2_hsotg *hsotg, bool select_phy)
 			usbcfg |= GUSBCFG_PHYSEL;
 			dwc2_writel(hsotg, usbcfg, GUSBCFG);
 
+			dwc2_set_clock_switch_timer(hsotg);
+
 			/* Reset after a PHY select */
 			retval = dwc2_core_reset(hsotg, false);
 
diff --git a/drivers/usb/dwc2/hw.h b/drivers/usb/dwc2/hw.h
index 5e449393b0d7..48699caa8739 100644
--- a/drivers/usb/dwc2/hw.h
+++ b/drivers/usb/dwc2/hw.h
@@ -99,6 +99,17 @@
 #define GRSTCTL_AHBIDLE			BIT(31)
 #define GRSTCTL_DMAREQ			BIT(30)
 #define GRSTCTL_CSFTRST_DONE		BIT(29)
+#define GRSTCTL_CLOCK_SWITH_TIMER_MASK		(0x7 << 11)
+#define GRSTCTL_CLOCK_SWITH_TIMER_SHIFT		11
+#define GRSTCTL_CLOCK_SWITH_TIMER_VALUE_19		0x0
+#define GRSTCTL_CLOCK_SWITH_TIMER_VALUE_15		0x1
+#define GRSTCTL_CLOCK_SWITH_TIMER_VALUE_147		0x2
+#define GRSTCTL_CLOCK_SWITH_TIMER_VALUE_50		0x3
+#define GRSTCTL_CLOCK_SWITH_TIMER_VALUE_100		0x4
+#define GRSTCTL_CLOCK_SWITH_TIMER_VALUE_125		0x5
+#define GRSTCTL_CLOCK_SWITH_TIMER_VALUE_200		0x6
+#define GRSTCTL_CLOCK_SWITH_TIMER_VALUE_DIS		0x7
+#define GRSTCTL_CLOCK_SWITH_TIMER(_x)		((_x) << 11)
 #define GRSTCTL_TXFNUM_MASK		(0x1f << 6)
 #define GRSTCTL_TXFNUM_SHIFT		6
 #define GRSTCTL_TXFNUM_LIMIT		0x1f