msm: ehci-hsic: Add support to disable internal clock gating
EHCI cores on latest MSMs have internal clock gating enabled
by default. Stability issues (random enumeration failures)
have been observed with some CORES where clock gating feature
doesn't work as expected. Hence add support to disable clock
gating in hardware.
Change-Id: I5209a68409ad04cba53c14c0e813aa0b925cf98e
CRs-Fixed: 538509
Signed-off-by: ChandanaKishori Chiluveru <cchilu@codeaurora.org>
diff --git a/drivers/usb/host/ehci-msm-hsic.c b/drivers/usb/host/ehci-msm-hsic.c
index 3688885..cfa7f6a 100644
--- a/drivers/usb/host/ehci-msm-hsic.c
+++ b/drivers/usb/host/ehci-msm-hsic.c
@@ -560,6 +560,7 @@
struct usb_hcd *hcd = hsic_to_hcd(mehci);
int ret;
struct msm_hsic_host_platform_data *pdata = mehci->dev->platform_data;
+ u32 temp;
msm_hsic_clk_reset(mehci);
@@ -617,6 +618,10 @@
ulpi_write(mehci, 0xA9, 0x30);
}
+ temp = readl_relaxed(USB_GENCONFIG2);
+ temp &= ~GENCFG2_SYS_CLK_HOST_DEV_GATE_EN;
+ writel_relaxed(temp, USB_GENCONFIG2);
+
/*disable auto resume*/
ulpi_write(mehci, ULPI_IFC_CTRL_AUTORESUME, ULPI_CLR(ULPI_IFC_CTRL));
diff --git a/include/linux/usb/msm_hsusb_hw.h b/include/linux/usb/msm_hsusb_hw.h
index c8c2ed1..2b103e8 100644
--- a/include/linux/usb/msm_hsusb_hw.h
+++ b/include/linux/usb/msm_hsusb_hw.h
@@ -18,6 +18,7 @@
#define USB_AHBBURST (MSM_USB_BASE + 0x0090)
#define USB_AHBMODE (MSM_USB_BASE + 0x0098)
+#define USB_GENCONFIG2 (MSM_USB_BASE + 0x00A0)
#define USB_CAPLENGTH (MSM_USB_BASE + 0x0100) /* 8 bit */
#define USB_HS_GPTIMER_BASE (MSM_USB_BASE + 0x80)
@@ -32,6 +33,8 @@
#define USB_USBINTR (MSM_USB_BASE + 0x0148)
#define USB_FRINDEX (MSM_USB_BASE + 0x014C)
+#define GENCFG2_SYS_CLK_HOST_DEV_GATE_EN BIT(13)
+
#define PORTSC_PHCD (1 << 23) /* phy suspend mode */
#define PORTSC_PTS_MASK (3 << 30)
#define PORTSC_PTS_ULPI (3 << 30)