[PATCH V2] usb: dwc3: xilinx: add reset-controller support

[Piyush Mehta <piyush.mehta@amd.com>]

Add a reset-controller for supporting Xilinx versal platforms. To reset
the USB controller, get the reset ID from device-tree and using ID trigger
the reset, with the assert and deassert reset controller APIs for USB
controller initialization.

Signed-off-by: Piyush Mehta <piyush.mehta@amd.com>
---
Changes in V2:
- Removed unnecessary delay between assert and deassert.
- Updated commit message.

Link: https://lore.kernel.org/all/20231005142215.1530-1-piyush.mehta@amd.com/
---
 drivers/usb/dwc3/dwc3-xilinx.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/usb/dwc3/dwc3-xilinx.c b/drivers/usb/dwc3/dwc3-xilinx.c
index 19307d24f3a0..5b7e92f476de 100644
--- a/drivers/usb/dwc3/dwc3-xilinx.c
+++ b/drivers/usb/dwc3/dwc3-xilinx.c
@@ -32,9 +32,6 @@
 #define XLNX_USB_TRAFFIC_ROUTE_CONFIG		0x005C
 #define XLNX_USB_TRAFFIC_ROUTE_FPD		0x1
 
-/* Versal USB Reset ID */
-#define VERSAL_USB_RESET_ID			0xC104036
-
 #define XLNX_USB_FPD_PIPE_CLK			0x7c
 #define PIPE_CLK_DESELECT			1
 #define PIPE_CLK_SELECT				0
@@ -72,20 +69,23 @@ static void dwc3_xlnx_mask_phy_rst(struct dwc3_xlnx *priv_data, bool mask)
 static int dwc3_xlnx_init_versal(struct dwc3_xlnx *priv_data)
 {
 	struct device		*dev = priv_data->dev;
+	struct reset_control	*crst;
 	int			ret;
 
+	crst = devm_reset_control_get_exclusive(dev, NULL);
+	if (IS_ERR(crst))
+		return dev_err_probe(dev, PTR_ERR(crst), "failed to get reset signal\n");
+
 	dwc3_xlnx_mask_phy_rst(priv_data, false);
 
 	/* Assert and De-assert reset */
-	ret = zynqmp_pm_reset_assert(VERSAL_USB_RESET_ID,
-				     PM_RESET_ACTION_ASSERT);
+	ret = reset_control_assert(crst);
 	if (ret < 0) {
 		dev_err_probe(dev, ret, "failed to assert Reset\n");
 		return ret;
 	}
 
-	ret = zynqmp_pm_reset_assert(VERSAL_USB_RESET_ID,
-				     PM_RESET_ACTION_RELEASE);
+	ret = reset_control_deassert(crst);
 	if (ret < 0) {
 		dev_err_probe(dev, ret, "failed to De-assert Reset\n");
 		return ret;
-- 
2.17.1