From: Dinh Nguyen <dinguyen@xxxxxxxxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxxxxxxxx>
Acked-by: John Youn <johnyoun@xxxxxxxxxxxx>
Tested-by: Stefan Wahren <stefan.wahren@xxxxxxxx>
---
v7: Use devm_reset_control_get_optional()
v6: fix 80 line checkpatch warning in dev_err print
v5: updated error conditions for not finding the reset property
v4: use dev_dbg() if not a -EPROBE_DEFER
v3: fix compile error
v2: move to lowlevel_hw_init()
---
drivers/usb/dwc2/core.h | 1 +
drivers/usb/dwc2/platform.c | 22 ++++++++++++++++++++++
2 files changed, 23 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..d34f169 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 +338,24 @@ static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
{
int i, ret;
+ hsotg->reset = devm_reset_control_get_optional(hsotg->dev, "dwc2");
+ if (IS_ERR(hsotg->reset)) {
+ ret = PTR_ERR(hsotg->reset);
+ switch (ret) {
+ case -ENOENT:
+ case -ENOTSUPP:
+ hsotg->reset = NULL;
+ break;
+ default:
+ dev_err(hsotg->dev, "error getting reset control %d\n",
+ ret);
+ return ret;
+ }
+ }
+
+ if (hsotg->reset)
+ reset_control_deassert(hsotg->reset);
+
/* Set default UTMI width */
hsotg->phyif = GUSBCFG_PHYIF16;
@@ -434,6 +453,9 @@ 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;
}
--
1.7.9.5
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