[U-Boot] [PATCH v2] usb: dwc2: Add reset ctrl to driver

[Ley Foon Tan]

Add code to reset all reset signals as in usb DT node. A reset property
is an optional feature, so only print out a warning and do not fail if a
reset property is not present.

If a reset property is discovered, then use it to deassert, thus
bringing the IP out of reset.

Signed-off-by: Ley Foon Tan <ley.foon.tan at intel.com>

---
v2:
- Assert reset when .remove.
---
 drivers/usb/host/dwc2.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/drivers/usb/host/dwc2.c b/drivers/usb/host/dwc2.c
index cbe065b..bee3b33 100644
--- a/drivers/usb/host/dwc2.c
+++ b/drivers/usb/host/dwc2.c
@@ -15,6 +15,7 @@
 #include <wait_bit.h>
 #include <asm/io.h>
 #include <power/regulator.h>
+#include <reset.h>
 
 #include "dwc2.h"
 
@@ -49,6 +50,8 @@ struct dwc2_priv {
 	 */
 	bool hnp_srp_disable;
 	bool oc_disable;
+
+	struct reset_ctl_bulk	resets;
 };
 
 #ifndef CONFIG_DM_USB
@@ -1124,11 +1127,37 @@ int _submit_int_msg(struct dwc2_priv *priv, struct usb_device *dev,
 	}
 }
 
+static int dwc2_reset(struct udevice *dev)
+{
+	int ret;
+	struct dwc2_priv *priv = dev_get_priv(dev);
+
+	ret = reset_get_bulk(dev, &priv->resets);
+	if (ret) {
+		dev_warn(dev, "Can't get reset: %d\n", ret);
+		return ret;
+	}
+
+	ret = reset_deassert_bulk(&priv->resets);
+	if (ret) {
+		reset_release_bulk(&priv->resets);
+		dev_err(dev, "Failed to reset: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
 static int dwc2_init_common(struct udevice *dev, struct dwc2_priv *priv)
 {
 	struct dwc2_core_regs *regs = priv->regs;
 	uint32_t snpsid;
 	int i, j;
+	int ret;
+
+	ret = dwc2_reset(dev);
+	if (ret)
+		return ret;
 
 	snpsid = readl(&regs->gsnpsid);
 	dev_info(dev, "Core Release: %x.%03x\n",
@@ -1303,6 +1332,8 @@ static int dwc2_usb_remove(struct udevice *dev)
 
 	dwc2_uninit_common(priv->regs);
 
+	reset_release_bulk(&priv->resets);
+
 	return 0;
 }
 
-- 
2.2.2