USB: bcma: add support for controlling bus power through GPIO

On some boards a GPIO is needed to activate USB controller. Make it
possible to specify such a GPIO in device tree.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/bcma-hcd.c

@@ -24,6 +24,8 @@
 #include <linux/platform_device.h>
 #include <linux/module.h>
 #include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
 #include <linux/usb/ehci_pdriver.h>
 #include <linux/usb/ohci_pdriver.h>
 
@@ -224,6 +226,23 @@ static void bcma_hcd_init_chip_arm(struct bcma_device *dev)
 	}
 }
 
+static void bcma_hci_platform_power_gpio(struct bcma_device *dev, bool val)
+{
+	int gpio;
+
+	gpio = of_get_named_gpio(dev->dev.of_node, "vcc-gpio", 0);
+	if (!gpio_is_valid(gpio))
+		return;
+
+	if (val) {
+		gpio_request(gpio, "bcma-hcd-gpio");
+		gpio_set_value(gpio, 1);
+	} else {
+		gpio_set_value(gpio, 0);
+		gpio_free(gpio);
+	}
+}
+
 static const struct usb_ehci_pdata ehci_pdata = {
 };
 
@@ -295,6 +314,8 @@ static int bcma_hcd_probe(struct bcma_device *dev)
 	if (!usb_dev)
 		return -ENOMEM;
 
+	bcma_hci_platform_power_gpio(dev, true);
+
 	switch (dev->id.id) {
 	case BCMA_CORE_NS_USB20:
 		bcma_hcd_init_chip_arm(dev);
@@ -347,6 +368,7 @@ static void bcma_hcd_remove(struct bcma_device *dev)
 
 static void bcma_hcd_shutdown(struct bcma_device *dev)
 {
+	bcma_hci_platform_power_gpio(dev, false);
 	bcma_core_disable(dev, 0);
 }
 
@@ -354,6 +376,7 @@ static void bcma_hcd_shutdown(struct bcma_device *dev)
 
 static int bcma_hcd_suspend(struct bcma_device *dev)
 {
+	bcma_hci_platform_power_gpio(dev, false);
 	bcma_core_disable(dev, 0);
 
 	return 0;
@@ -361,6 +384,7 @@ static int bcma_hcd_suspend(struct bcma_device *dev)
 
 static int bcma_hcd_resume(struct bcma_device *dev)
 {
+	bcma_hci_platform_power_gpio(dev, true);
 	bcma_core_enable(dev, 0);
 
 	return 0;