usb: misc: onboard_usb_hub: Add reset-gpio support

Despite default reset upon probe, release reset line after powering up
the hub and assert reset again before powering down.
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Link: https://lore.kernel.org/r/20220727141117.909361-1-alexander.stein@ew.tq-group.com

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/misc/onboard_usb_hub.c

@@ -7,6 +7,7 @@
 
 #include <linux/device.h>
 #include <linux/export.h>
+#include <linux/gpio/consumer.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
@@ -38,6 +39,8 @@ struct usbdev_node {
 struct onboard_hub {
 	struct regulator *vdd;
 	struct device *dev;
+	const struct onboard_hub_pdata *pdata;
+	struct gpio_desc *reset_gpio;
 	bool always_powered_in_suspend;
 	bool is_powered_on;
 	bool going_away;
@@ -56,6 +59,9 @@ static int onboard_hub_power_on(struct onboard_hub *hub)
 		return err;
 	}
 
+	fsleep(hub->pdata->reset_us);
+	gpiod_set_value_cansleep(hub->reset_gpio, 0);
+
 	hub->is_powered_on = true;
 
 	return 0;
@@ -65,6 +71,11 @@ static int onboard_hub_power_off(struct onboard_hub *hub)
 {
 	int err;
 
+	if (hub->reset_gpio) {
+		gpiod_set_value_cansleep(hub->reset_gpio, 1);
+		fsleep(hub->pdata->reset_us);
+	}
+
 	err = regulator_disable(hub->vdd);
 	if (err) {
 		dev_err(hub->dev, "failed to disable regulator: %d\n", err);
@@ -219,6 +230,7 @@ static void onboard_hub_attach_usb_driver(struct work_struct *work)
 
 static int onboard_hub_probe(struct platform_device *pdev)
 {
+	const struct of_device_id *of_id;
 	struct device *dev = &pdev->dev;
 	struct onboard_hub *hub;
 	int err;
@@ -227,10 +239,26 @@ static int onboard_hub_probe(struct platform_device *pdev)
 	if (!hub)
 		return -ENOMEM;
 
+	of_id = of_match_device(onboard_hub_match, &pdev->dev);
+	if (!of_id)
+		return -ENODEV;
+
+	hub->pdata = of_id->data;
+	if (!hub->pdata)
+		return -EINVAL;
+
 	hub->vdd = devm_regulator_get(dev, "vdd");
 	if (IS_ERR(hub->vdd))
 		return PTR_ERR(hub->vdd);
 
+	hub->reset_gpio = devm_gpiod_get_optional(dev, "reset",
+						  GPIOD_OUT_HIGH);
+	if (IS_ERR(hub->reset_gpio))
+		return dev_err_probe(dev, PTR_ERR(hub->reset_gpio), "failed to get reset GPIO\n");
+
+	if (hub->reset_gpio)
+		fsleep(hub->pdata->reset_us);
+
 	hub->dev = dev;
 	mutex_init(&hub->lock);
 	INIT_LIST_HEAD(&hub->udev_list);

drivers/usb/misc/onboard_usb_hub.h

@@ -6,12 +6,24 @@
 #ifndef _USB_MISC_ONBOARD_USB_HUB_H
 #define _USB_MISC_ONBOARD_USB_HUB_H
 
+struct onboard_hub_pdata {
+	unsigned long reset_us;		/* reset pulse width in us */
+};
+
+static const struct onboard_hub_pdata microchip_usb424_data = {
+	.reset_us = 1,
+};
+
+static const struct onboard_hub_pdata realtek_rts5411_data = {
+	.reset_us = 0,
+};
+
 static const struct of_device_id onboard_hub_match[] = {
-	{ .compatible = "usb424,2514" },
-	{ .compatible = "usbbda,411" },
-	{ .compatible = "usbbda,5411" },
-	{ .compatible = "usbbda,414" },
-	{ .compatible = "usbbda,5414" },
+	{ .compatible = "usb424,2514", .data = &microchip_usb424_data, },
+	{ .compatible = "usbbda,411", .data = &realtek_rts5411_data, },
+	{ .compatible = "usbbda,5411", .data = &realtek_rts5411_data, },
+	{ .compatible = "usbbda,414", .data = &realtek_rts5411_data, },
+	{ .compatible = "usbbda,5414", .data = &realtek_rts5411_data, },
 	{}
 };