[PATCH v7 1/7] usb: onboard-hub: Add reset-gpio support

[Venkatesh Yadav Abbarapu]

As part of the reset, sets the direction of the pin to output before
toggling the pin. Delay of millisecond is added in between low and
high to meet the setup and hold time requirement of the reset.

Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu at amd.com>
---
 common/usb_onboard_hub.c | 42 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 41 insertions(+), 1 deletion(-)

diff --git a/common/usb_onboard_hub.c b/common/usb_onboard_hub.c
index 68a04ac041..4174575893 100644
--- a/common/usb_onboard_hub.c
+++ b/common/usb_onboard_hub.c
@@ -7,14 +7,51 @@
  * Mostly inspired by Linux kernel v6.1 onboard_usb_hub driver
  */
 
+#include <asm/gpio.h>
 #include <dm.h>
 #include <dm/device_compat.h>
+#include <linux/delay.h>
 #include <power/regulator.h>
 
 struct onboard_hub {
 	struct udevice *vdd;
+	struct gpio_desc *reset_gpio;
 };
 
+struct onboard_hub_data {
+	unsigned long reset_us;
+	unsigned long power_on_delay_us;
+};
+
+int usb_onboard_hub_reset(struct udevice *dev)
+{
+	struct onboard_hub_data *data =
+		(struct onboard_hub_data *)dev_get_driver_data(dev);
+	struct onboard_hub *hub = dev_get_priv(dev);
+	int ret;
+
+	hub->reset_gpio = devm_gpiod_get_optional(dev, "reset",
+						  GPIOD_IS_OUT | GPIOD_ACTIVE_LOW);
+
+	/* property is optional, don't return error! */
+	if (!hub->reset_gpio)
+		return 0;
+
+	ret = dm_gpio_set_value(hub->reset_gpio, 1);
+	if (ret)
+		return ret;
+
+	udelay(data->reset_us);
+
+	ret = dm_gpio_set_value(hub->reset_gpio, 0);
+	if (ret)
+		return ret;
+
+	udelay(data->power_on_delay_us);
+
+	return 0;
+}
+
 static int usb_onboard_hub_probe(struct udevice *dev)
 {
 	struct onboard_hub *hub = dev_get_priv(dev);
@@ -30,7 +67,7 @@ static int usb_onboard_hub_probe(struct udevice *dev)
 	if (ret)
 		dev_err(dev, "can't enable vdd-supply: %d\n", ret);
 
-	return ret;
+	return usb_onboard_hub_reset(dev);
 }
 
 static int usb_onboard_hub_remove(struct udevice *dev)
@@ -38,6 +75,9 @@ static int usb_onboard_hub_remove(struct udevice *dev)
 	struct onboard_hub *hub = dev_get_priv(dev);
 	int ret;
 
+	if (hub->reset_gpio)
+		dm_gpio_free(hub->reset_gpio->dev, hub->reset_gpio);
+
 	ret = regulator_set_enable_if_allowed(hub->vdd, false);
 	if (ret)
 		dev_err(dev, "can't disable vdd-supply: %d\n", ret);
-- 
2.17.1