[PATCH 1/2] usb: dwc2: Add reset control to dwc2

[<dinguyen-yzvPICuk2ABMcg4IHK0kFoH6Mc4MB0Vx@public.gmane.org>]

From: Dinh Nguyen <dinguyen-yzvPICuk2ABMcg4IHK0kFoH6Mc4MB0Vx@public.gmane.org>

Allow for platforms that have a reset controller driver in place to bring
the USB IP out of reset.

Signed-off-by: Dinh Nguyen <dinguyen-yzvPICuk2ABMcg4IHK0kFoH6Mc4MB0Vx@public.gmane.org>
Cc: John Youn <johnyoun-HKixBCOQz3hWk0Htik3J/w@public.gmane.org>
---
 drivers/usb/dwc2/core.h     |    1 +
 drivers/usb/dwc2/platform.c |   15 +++++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
index 3c58d63..f748132 100644
--- a/drivers/usb/dwc2/core.h
+++ b/drivers/usb/dwc2/core.h
@@ -837,6 +837,7 @@ struct dwc2_hsotg {
 	void *priv;
 	int     irq;
 	struct clk *clk;
+	struct reset_control *reset;
 
 	unsigned int queuing_high_bandwidth:1;
 	unsigned int srp_success:1;
diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
index 88629be..b1fa9dd 100644
--- a/drivers/usb/dwc2/platform.c
+++ b/drivers/usb/dwc2/platform.c
@@ -45,6 +45,7 @@
 #include <linux/platform_device.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_data/s3c-hsotg.h>
+#include <linux/reset.h>
 
 #include <linux/usb/of.h>
 
@@ -337,6 +338,9 @@ static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
 {
 	int i, ret;
 
+	if(hsotg->reset)
+		reset_control_deassert(hsotg->reset);
+
 	/* Set default UTMI width */
 	hsotg->phyif = GUSBCFG_PHYIF16;
 
@@ -434,6 +438,9 @@ static int dwc2_driver_remove(struct platform_device *dev)
 	if (hsotg->ll_hw_enabled)
 		dwc2_lowlevel_hw_disable(hsotg);
 
+	if (hsotg->reset)
+		reset_control_assert(hsotg->reset);
+
 	return 0;
 }
 
@@ -529,6 +536,14 @@ static int dwc2_driver_probe(struct platform_device *dev)
 	dev_dbg(&dev->dev, "mapped PA %08lx to VA %p\n",
 		(unsigned long)res->start, hsotg->regs);
 
+	hsotg->reset = devm_reset_control_get(&dev->dev, "dwc2");
+	if (IS_ERR(hsotg->reset)) {
+		dev_info(&dev->dev, "Could not get reset control!\n");
+		if (PTR_ERR(hsotg->reset) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+		hsotg->reset = NULL;
+	}
+
 	retval = dwc2_lowlevel_hw_init(hsotg);
 	if (retval)
 		return retval;
-- 
1.7.9.5

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