diff options
Diffstat (limited to 'drivers/usb/chipidea/otg.c')
| -rw-r--r-- | drivers/usb/chipidea/otg.c | 34 |
1 files changed, 30 insertions, 4 deletions
diff --git a/drivers/usb/chipidea/otg.c b/drivers/usb/chipidea/otg.c index 03b6743461d1..a829607c3e4d 100644 --- a/drivers/usb/chipidea/otg.c +++ b/drivers/usb/chipidea/otg.c @@ -104,7 +104,31 @@ void ci_handle_vbus_change(struct ci_hdrc *ci) usb_gadget_vbus_disconnect(&ci->gadget); } -#define CI_VBUS_STABLE_TIMEOUT_MS 5000 +/** + * When we switch to device mode, the vbus value should be lower + * than OTGSC_BSV before connecting to host. + * + * @ci: the controller + * + * This function returns an error code if timeout + */ +static int hw_wait_vbus_lower_bsv(struct ci_hdrc *ci) +{ + unsigned long elapse = jiffies + msecs_to_jiffies(5000); + u32 mask = OTGSC_BSV; + + while (hw_read_otgsc(ci, mask)) { + if (time_after(jiffies, elapse)) { + dev_err(ci->dev, "timeout waiting for %08x in OTGSC\n", + mask); + return -ETIMEDOUT; + } + msleep(20); + } + + return 0; +} + static void ci_handle_id_switch(struct ci_hdrc *ci) { enum ci_role role = ci_otg_role(ci); @@ -116,9 +140,11 @@ static void ci_handle_id_switch(struct ci_hdrc *ci) ci_role_stop(ci); if (role == CI_ROLE_GADGET) - /* wait vbus lower than OTGSC_BSV */ - hw_wait_reg(ci, OP_OTGSC, OTGSC_BSV, 0, - CI_VBUS_STABLE_TIMEOUT_MS); + /* + * wait vbus lower than OTGSC_BSV before connecting + * to host + */ + hw_wait_vbus_lower_bsv(ci); ci_role_start(ci, role); } |