Commit deabd513 authored by Yoshihiro Shimoda's avatar Yoshihiro Shimoda Committed by Greg Kroah-Hartman

usb: gadget: udc: renesas_usb3: add a safety connection way for forced_b_device

[ Upstream commit ceb94bc5 ]

This patch adds a safety connection way for "forced_b_device" with
"workaround_for_vbus" like below:

< Example for R-Car E3 Ebisu >
 # modprobe <any usb gadget driver>
 # echo 1 > /sys/kernel/debug/ee020000.usb/b_device
 (connect a usb cable to host side.)
 # echo 2 > /sys/kernel/debug/ee020000.usb/b_device

Previous code should have connected a usb cable before the "b_device"
is set to 1 on the Ebisu board. However, if xHCI driver on the board
is probed, it causes some troubles:
 - Conflicts USB VBUS/signals between the board and another host.
 - "Cannot enable. Maybe the USB cable is bad?" might happen on
   both the board and another host with a usb hub.
 - Cannot enumerate a usb gadget correctly because an interruption
   of VBUS change happens unexpectedly.
Reported-by: default avatarKazuya Mizuguchi <[email protected]>
Signed-off-by: Yoshihiro Shimoda's avatarYoshihiro Shimoda <[email protected]>
Signed-off-by: default avatarFelipe Balbi <[email protected]>
Signed-off-by: default avatarSasha Levin <[email protected]>
parent d8e74c74
......@@ -358,6 +358,7 @@ struct renesas_usb3 {
bool extcon_host; /* check id and set EXTCON_USB_HOST */
bool extcon_usb; /* check vbus and set EXTCON_USB */
bool forced_b_device;
bool start_to_connect;
#define gadget_to_renesas_usb3(_gadget) \
......@@ -476,6 +477,7 @@ static void usb3_init_axi_bridge(struct renesas_usb3 *usb3)
static void usb3_init_epc_registers(struct renesas_usb3 *usb3)
usb3_write(usb3, ~0, USB3_USB_INT_STA_1);
if (!usb3->workaround_for_vbus)
usb3_enable_irq_1(usb3, USB_INT_1_VBUS_CNG);
......@@ -700,8 +702,7 @@ static void usb3_mode_config(struct renesas_usb3 *usb3, bool host, bool a_dev)
usb3_set_mode_by_role_sw(usb3, host);
usb3_vbus_out(usb3, a_dev);
/* for A-Peripheral or forced B-device mode */
if ((!host && a_dev) ||
(usb3->workaround_for_vbus && usb3->forced_b_device))
if ((!host && a_dev) || usb3->start_to_connect)
spin_unlock_irqrestore(&usb3->lock, flags);
......@@ -2432,7 +2433,11 @@ static ssize_t renesas_usb3_b_device_write(struct file *file,
if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
return -EFAULT;
if (!strncmp(buf, "1", 1))
usb3->start_to_connect = false;
if (usb3->workaround_for_vbus && usb3->forced_b_device &&
!strncmp(buf, "2", 1))
usb3->start_to_connect = true;
else if (!strncmp(buf, "1", 1))
usb3->forced_b_device = true;
usb3->forced_b_device = false;
......@@ -2440,7 +2445,7 @@ static ssize_t renesas_usb3_b_device_write(struct file *file,
if (usb3->workaround_for_vbus)
/* Let this driver call usb3_connect() anyway */
/* Let this driver call usb3_connect() if needed */
return count;
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