[PATCH v2 1/1] usb: dwc3: Add optional VBUS regulator support to SpacemiT K1

[Chukun Pan <amadeus@jmu.edu.cn>]

Some SpacemiT K1 boards (like OrangePi R2S) provide USB VBUS
through a controllable regulator. Add support for the optional
vbus-supply property so the regulator can be properly managed
in host mode instead of left always-on. Note that this doesn't
apply to USB Hub downstream ports with different VBUS supplies.

The enabled and disabled actions of the regulator are handled
automatically by devm_regulator_get_enable_optional().

Signed-off-by: Chukun Pan <amadeus@jmu.edu.cn>
---
 drivers/usb/dwc3/dwc3-generic-plat.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/dwc3-generic-plat.c b/drivers/usb/dwc3/dwc3-generic-plat.c
index e846844e0023..bd281fde5ce0 100644
--- a/drivers/usb/dwc3/dwc3-generic-plat.c
+++ b/drivers/usb/dwc3/dwc3-generic-plat.c
@@ -12,6 +12,8 @@
 #include <linux/reset.h>
 #include <linux/regmap.h>
 #include <linux/mfd/syscon.h>
+#include <linux/regulator/consumer.h>
+#include <linux/usb/otg.h>
 #include "glue.h"
 
 #define EIC7700_HSP_BUS_FILTER_EN	BIT(0)
@@ -69,6 +71,20 @@ static int dwc3_eic7700_init(struct dwc3_generic *dwc3g)
 	return 0;
 }
 
+static int dwc3_spacemit_k1_init(struct dwc3_generic *dwc3g)
+{
+	struct device *dev = dwc3g->dev;
+
+	if (usb_get_dr_mode(dev) == USB_DR_MODE_HOST) {
+		int ret = devm_regulator_get_enable_optional(dev, "vbus");
+
+		if (ret && ret != -ENODEV)
+			return dev_err_probe(dev, ret, "failed to enable VBUS\n");
+	}
+
+	return 0;
+}
+
 static int dwc3_generic_probe(struct platform_device *pdev)
 {
 	const struct dwc3_generic_config *plat_config;
@@ -210,10 +226,14 @@ static const struct dwc3_generic_config eic7700_dwc3 =  {
 	.properties = DWC3_DEFAULT_PROPERTIES,
 };
 
+static const struct dwc3_generic_config spacemit_k1_dwc3 = {
+	.init = dwc3_spacemit_k1_init,
+};
+
 static const struct of_device_id dwc3_generic_of_match[] = {
-	{ .compatible = "spacemit,k1-dwc3", },
 	{ .compatible = "fsl,ls1028a-dwc3", &fsl_ls1028_dwc3},
 	{ .compatible = "eswin,eic7700-dwc3", &eic7700_dwc3},
+	{ .compatible = "spacemit,k1-dwc3", &spacemit_k1_dwc3},
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, dwc3_generic_of_match);
-- 
2.34.1