[PATCH 2/2] dwc3: add power down clock scale setting when init core

[Jun Li <jun.li@nxp.com>]

Set the right power down clock scale if the property
"snps,power-down-scale" is specified.

Signed-off-by: Li Jun <jun.li@nxp.com>
---
 drivers/usb/dwc3/core.c | 15 +++++++++++++++
 drivers/usb/dwc3/core.h |  1 +
 2 files changed, 16 insertions(+)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 88c80fc..c41c0b2 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -878,6 +878,19 @@ static void dwc3_set_incr_burst_type(struct dwc3 *dwc)
 	dwc3_writel(dwc->regs, DWC3_GSBUSCFG0, cfg);
 }
 
+static void dwc3_set_power_down_clk_scale(struct dwc3 *dwc)
+{
+	u32 reg, scale;
+
+	if (!device_property_read_u32(dwc->dev, "snps,power-down-scale",
+				      &scale)) {
+		reg = dwc3_readl(dwc->regs, DWC3_GCTL);
+		reg &= ~(DWC3_GCTL_PWRDNSCALE_MASK);
+		reg |= DWC3_GCTL_PWRDNSCALE(scale);
+		dwc3_writel(dwc->regs, DWC3_GCTL, reg);
+	}
+}
+
 /**
  * dwc3_core_init - Low-level initialization of DWC3 Core
  * @dwc: Pointer to our controller context structure
@@ -908,6 +921,8 @@ static int dwc3_core_init(struct dwc3 *dwc)
 			dwc->maximum_speed = USB_SPEED_HIGH;
 	}
 
+	dwc3_set_power_down_clk_scale(dwc);
+
 	ret = dwc3_phy_setup(dwc);
 	if (ret)
 		goto err0;
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 5bfb625..8cdaab3 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -216,6 +216,7 @@
 
 /* Global Configuration Register */
 #define DWC3_GCTL_PWRDNSCALE(n)	((n) << 19)
+#define DWC3_GCTL_PWRDNSCALE_MASK	DWC3_GCTL_PWRDNSCALE(0x1fff)
 #define DWC3_GCTL_U2RSTECN	BIT(16)
 #define DWC3_GCTL_RAMCLKSEL(x)	(((x) & DWC3_GCTL_CLK_MASK) << 6)
 #define DWC3_GCTL_CLK_BUS	(0)
-- 
2.7.4