Add controller reset API, currently it is used for device mode only.
It may be used for host/otg driver in future.
Ususally, we need this API for dual-role switch and back from hibernation
suspend to let the controller at default state.
Signed-off-by: Peter Chen <peter.chen@xxxxxxxxxxxxx>
---
Changes for v3:
- Add more description for why this API is needed
- Fix one indentation problem
- Change error message for "error for reset" to "error resetting controller"
drivers/usb/chipidea/core.c | 32 ++++++++++++++++++++++++++++----
1 file changed, 28 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c
index bd74f27..48b25d9 100644
--- a/drivers/usb/chipidea/core.c
+++ b/drivers/usb/chipidea/core.c
@@ -385,20 +385,44 @@ static int ci_usb_phy_init(struct ci_hdrc *ci)
}
/**
- * hw_device_reset: resets chip (execute without interruption)
+ * hw_controller_reset: do controller reset
* @ci: the controller
*
* This function returns an error code
*/
+static int hw_controller_reset(struct ci_hdrc *ci)
+{
+ int count = 0;
+
+ hw_write(ci, OP_USBCMD, USBCMD_RST, USBCMD_RST);
+ while (hw_read(ci, OP_USBCMD, USBCMD_RST)) {
+ udelay(10);
+ if (count++ > 1000)
+ return -ETIMEDOUT;
+ }
+
+ return 0;
+}
+
+/**
+ * hw_device_reset: resets chip (execute without interruption)
+ * @ci: the controller
+ *
+ * This function returns an error code
+ */
int hw_device_reset(struct ci_hdrc *ci, u32 mode)
{
+ int ret;
+
/* should flush & stop before reset */
hw_write(ci, OP_ENDPTFLUSH, ~0, ~0);
hw_write(ci, OP_USBCMD, USBCMD_RS, 0);
- hw_write(ci, OP_USBCMD, USBCMD_RST, USBCMD_RST);
- while (hw_read(ci, OP_USBCMD, USBCMD_RST))
- udelay(10); /* not RTOS friendly */
+ ret = hw_controller_reset(ci);
+ if (ret) {
+ dev_err(ci->dev, "error resetting controller, ret=%d\n", ret);
+ return ret;
+ }
if (ci->platdata->notify_event)
ci->platdata->notify_event(ci,
--
1.9.1
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