usb: musb: jz4740: Register USB role switch

Register a USB role switch, in order to get notified by the connector
driver when the USB role changes. The notification is then transmitted
to the PHY.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Bin Liu <b-liu@ti.com>
Link: https://lore.kernel.org/r/20200316211136.2274-5-b-liu@ti.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/musb/Kconfig

@@ -113,6 +113,7 @@ config USB_MUSB_JZ4740
 	depends on MIPS || COMPILE_TEST
 	depends on USB_MUSB_GADGET
 	depends on USB=n || USB_OTG_BLACKLIST_HUB
+	select USB_ROLE_SWITCH
 
 config USB_MUSB_MEDIATEK
 	tristate "MediaTek platforms"

drivers/usb/musb/jz4740.c

@@ -12,13 +12,16 @@
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
+#include <linux/usb/role.h>
 #include <linux/usb/usb_phy_generic.h>
 
 #include "musb_core.h"
 
 struct jz4740_glue {
 	struct platform_device	*pdev;
+	struct musb		*musb;
 	struct clk		*clk;
+	struct usb_role_switch	*role_sw;
 };
 
 static irqreturn_t jz4740_musb_interrupt(int irq, void *__hci)
@@ -72,11 +75,40 @@ static const struct musb_hdrc_config jz4740_musb_config = {
 	.fifo_cfg_size	= ARRAY_SIZE(jz4740_musb_fifo_cfg),
 };
 
+static int jz4740_musb_role_switch_set(struct usb_role_switch *sw,
+				       enum usb_role role)
+{
+	struct jz4740_glue *glue = usb_role_switch_get_drvdata(sw);
+	struct usb_phy *phy = glue->musb->xceiv;
+
+	switch (role) {
+	case USB_ROLE_NONE:
+		atomic_notifier_call_chain(&phy->notifier, USB_EVENT_NONE, phy);
+		break;
+	case USB_ROLE_DEVICE:
+		atomic_notifier_call_chain(&phy->notifier, USB_EVENT_VBUS, phy);
+		break;
+	case USB_ROLE_HOST:
+		atomic_notifier_call_chain(&phy->notifier, USB_EVENT_ID, phy);
+		break;
+	}
+
+	return 0;
+}
+
 static int jz4740_musb_init(struct musb *musb)
 {
 	struct device *dev = musb->controller->parent;
+	struct jz4740_glue *glue = dev_get_drvdata(dev);
+	struct usb_role_switch_desc role_sw_desc = {
+		.set = jz4740_musb_role_switch_set,
+		.driver_data = glue,
+		.fwnode = dev_fwnode(dev),
+	};
 	int err;
 
+	glue->musb = musb;
+
 	if (dev->of_node)
 		musb->xceiv = devm_usb_get_phy_by_phandle(dev, "phys", 0);
 	else
@@ -88,6 +120,12 @@ static int jz4740_musb_init(struct musb *musb)
 		return err;
 	}
 
+	glue->role_sw = usb_role_switch_register(dev, &role_sw_desc);
+	if (IS_ERR(glue->role_sw)) {
+		dev_err(dev, "Failed to register USB role switch");
+		return PTR_ERR(glue->role_sw);
+	}
+
 	/*
 	 * Silicon does not implement ConfigData register.
 	 * Set dyn_fifo to avoid reading EP config from hardware.
@@ -99,10 +137,20 @@ static int jz4740_musb_init(struct musb *musb)
 	return 0;
 }
 
+static int jz4740_musb_exit(struct musb *musb)
+{
+	struct jz4740_glue *glue = dev_get_drvdata(musb->controller->parent);
+
+	usb_role_switch_unregister(glue->role_sw);
+
+	return 0;
+}
+
 static const struct musb_platform_ops jz4740_musb_ops = {
 	.quirks		= MUSB_DMA_INVENTRA | MUSB_INDEXED_EP,
 	.fifo_mode	= 2,
 	.init		= jz4740_musb_init,
+	.exit		= jz4740_musb_exit,
 #ifdef CONFIG_USB_INVENTRA_DMA
 	.dma_init	= musbhs_dma_controller_create_noirq,
 	.dma_exit	= musbhs_dma_controller_destroy,