[PATCH v2 3/4] usb: xhci-dwc3: Add support for clocks/resets

[Samuel Holland]

Some platforms, like the Allwinner H6, do not have a separate glue layer
around the dwc3. Instead, they rely on the clocks/resets/phys referenced
from the dwc3 DT node itself. Add support for enabling the clocks/resets
referenced from the dwc3 DT node.

Signed-off-by: Samuel Holland <samuel at sholland.org>
---
 drivers/usb/host/xhci-dwc3.c | 56 ++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)

diff --git a/drivers/usb/host/xhci-dwc3.c b/drivers/usb/host/xhci-dwc3.c
index 3e0ae80cec..5b12d1358e 100644
--- a/drivers/usb/host/xhci-dwc3.c
+++ b/drivers/usb/host/xhci-dwc3.c
@@ -7,10 +7,12 @@
  * Author: Ramneek Mehresh<ramneek.mehresh at freescale.com>
  */
 
+#include <clk.h>
 #include <common.h>
 #include <dm.h>
 #include <generic-phy.h>
 #include <log.h>
+#include <reset.h>
 #include <usb.h>
 #include <dwc3-uboot.h>
 #include <linux/delay.h>
@@ -21,7 +23,9 @@
 #include <linux/usb/otg.h>
 
 struct xhci_dwc3_plat {
+	struct clk_bulk clks;
 	struct phy_bulk phys;
+	struct reset_ctl_bulk resets;
 };
 
 void dwc3_set_mode(struct dwc3 *dwc3_reg, u32 mode)
@@ -111,6 +115,46 @@ void dwc3_set_fladj(struct dwc3 *dwc3_reg, u32 val)
 }
 
 #if CONFIG_IS_ENABLED(DM_USB)
+static int xhci_dwc3_reset_init(struct udevice *dev,
+				struct xhci_dwc3_plat *plat)
+{
+	int ret;
+
+	ret = reset_get_bulk(dev, &plat->resets);
+	if (ret == -ENOTSUPP || ret == -ENOENT)
+		return 0;
+	else if (ret)
+		return ret;
+
+	ret = reset_deassert_bulk(&plat->resets);
+	if (ret) {
+		reset_release_bulk(&plat->resets);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int xhci_dwc3_clk_init(struct udevice *dev,
+			      struct xhci_dwc3_plat *plat)
+{
+	int ret;
+
+	ret = clk_get_bulk(dev, &plat->clks);
+	if (ret == -ENOSYS || ret == -ENOENT)
+		return 0;
+	if (ret)
+		return ret;
+
+	ret = clk_enable_bulk(&plat->clks);
+	if (ret) {
+		clk_release_bulk(&plat->clks);
+		return ret;
+	}
+
+	return 0;
+}
+
 static int xhci_dwc3_probe(struct udevice *dev)
 {
 	struct xhci_hcor *hcor;
@@ -122,6 +166,14 @@ static int xhci_dwc3_probe(struct udevice *dev)
 	u32 reg;
 	int ret;
 
+	ret = xhci_dwc3_reset_init(dev, plat);
+	if (ret)
+		return ret;
+
+	ret = xhci_dwc3_clk_init(dev, plat);
+	if (ret)
+		return ret;
+
 	hccr = (struct xhci_hccr *)((uintptr_t)dev_remap_addr(dev));
 	hcor = (struct xhci_hcor *)((uintptr_t)hccr +
 			HC_LENGTH(xhci_readl(&(hccr)->cr_capbase)));
@@ -171,6 +223,10 @@ static int xhci_dwc3_remove(struct udevice *dev)
 
 	dwc3_shutdown_phy(dev, &plat->phys);
 
+	clk_release_bulk(&plat->clks);
+
+	reset_release_bulk(&plat->resets);
+
 	return xhci_deregister(dev);
 }
 
-- 
2.26.2