Commit cc995c9e authored by Yoshihiro Shimoda's avatar Yoshihiro Shimoda Committed by Felipe Balbi
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usb: gadget: udc: renesas_usb3: add support for usb role swap

This patch adds support for usb role swap via sysfs "role".

For example:
 1) Connect a usb cable using 2 Salvator-X boards.
  - For A-Device, the cable is connected to CN11 (USB3.0 ch0).
  - For B-Device, the cable is connected to CN9 (USB2.0 ch0).
 2) On A-Device, you input the following command:
  # echo peripheral > /sys/devices/platform/soc/ee020000.usb/role
 3) On B-Device, you input the following command:
  # echo host > /sys/devices/platform/soc/ee080200.usb-phy/role

Then, the A-Device acts as a peripheral and the B-Device acts as
a host. Please note that A-Device must input the following command
if you want the board to act as a host again.
 # echo host > /sys/devices/platform/soc/ee020000.usb/role
Signed-off-by: default avatarYoshihiro Shimoda <>
Signed-off-by: default avatarFelipe Balbi <>
parent fbf4987a
What: /sys/devices/platform/<renesas_usb3's name>/role
Date: March 2017
KernelVersion: 4.13
Contact: Yoshihiro Shimoda <>
This file can be read and write.
The file can show/change the drd mode of usb.
Write the following string to change the mode:
"host" - switching mode from peripheral to host.
"peripheral" - switching mode from host to peripheral.
Read the file, then it shows the following strings:
"host" - The mode is host now.
"peripheral" - The mode is peripheral now.
......@@ -372,6 +372,11 @@ static void usb3_disable_pipe_irq(struct renesas_usb3 *usb3, int num)
usb3_clear_bit(usb3, USB_INT_2_PIPE(num), USB3_USB_INT_ENA_2);
static bool usb3_is_host(struct renesas_usb3 *usb3)
return !(usb3_read(usb3, USB3_DRD_CON) & DRD_CON_PERI_CON);
static void usb3_init_axi_bridge(struct renesas_usb3 *usb3)
/* Set AXI_INT */
......@@ -576,8 +581,14 @@ static void usb3_vbus_out(struct renesas_usb3 *usb3, bool enable)
static void usb3_mode_config(struct renesas_usb3 *usb3, bool host, bool a_dev)
unsigned long flags;
spin_lock_irqsave(&usb3->lock, flags);
usb3_set_mode(usb3, host);
usb3_vbus_out(usb3, a_dev);
if (!host && a_dev) /* for A-Peripheral */
spin_unlock_irqrestore(&usb3->lock, flags);
static bool usb3_is_a_device(struct renesas_usb3 *usb3)
......@@ -1837,11 +1848,49 @@ static const struct usb_gadget_ops renesas_usb3_gadget_ops = {
.set_selfpowered = renesas_usb3_set_selfpowered,
static ssize_t role_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
struct renesas_usb3 *usb3 = dev_get_drvdata(dev);
bool new_mode_is_host;
if (!usb3->driver)
return -ENODEV;
if (!strncmp(buf, "host", strlen("host")))
new_mode_is_host = true;
else if (!strncmp(buf, "peripheral", strlen("peripheral")))
new_mode_is_host = false;
return -EINVAL;
if (new_mode_is_host == usb3_is_host(usb3))
return -EINVAL;
usb3_mode_config(usb3, new_mode_is_host, usb3_is_a_device(usb3));
return count;
static ssize_t role_show(struct device *dev, struct device_attribute *attr,
char *buf)
struct renesas_usb3 *usb3 = dev_get_drvdata(dev);
if (!usb3->driver)
return -ENODEV;
return sprintf(buf, "%s\n", usb3_is_host(usb3) ? "host" : "peripheral");
static DEVICE_ATTR_RW(role);
/*------- platform_driver ------------------------------------------------*/
static int renesas_usb3_remove(struct platform_device *pdev)
struct renesas_usb3 *usb3 = platform_get_drvdata(pdev);
device_remove_file(&pdev->dev, &dev_attr_role);
......@@ -2044,6 +2093,10 @@ static int renesas_usb3_probe(struct platform_device *pdev)
if (ret < 0)
goto err_add_udc;
ret = device_create_file(&pdev->dev, &dev_attr_role);
if (ret < 0)
goto err_dev_create;
usb3->workaround_for_vbus = priv->workaround_for_vbus;
......@@ -2053,6 +2106,9 @@ static int renesas_usb3_probe(struct platform_device *pdev)
return 0;
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