diff options
author | Peter Chen <peter.chen@freescale.com> | 2013-08-14 12:44:12 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-08-14 12:37:20 -0700 |
commit | 22fa84455a2a80566ead8efe4b5e629f2375da60 (patch) | |
tree | c77615fc9011a7ab64dbe17082f85f0ae1b36c3d /drivers/usb/chipidea/core.c | |
parent | a107f8c505cd8606ae192d24c70b380e980fbe67 (diff) |
usb: chipidea: add wait vbus lower than OTGSC_BSV before role starts
When the gadget role starts, we need to make sure the vbus is lower
than OTGSC_BSV, or there will be an vbus interrupt since we use
B_SESSION_VALID as vbus interrupt to indicate connect and disconnect.
When the host role starts, it may not be useful to wait vbus to lower
than OTGSC_BSV, but it can indicate some hardware problems like the
vbus is still higher than OTGSC_BSV after we disconnect to host some
time later (5000 milliseconds currently), which is obvious not correct.
Tested-by: Marek Vasut <marex@denx.de>
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/chipidea/core.c')
-rw-r--r-- | drivers/usb/chipidea/core.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c index c95e098fe9db..94626409559a 100644 --- a/drivers/usb/chipidea/core.c +++ b/drivers/usb/chipidea/core.c @@ -294,6 +294,38 @@ int hw_device_reset(struct ci_hdrc *ci, u32 mode) return 0; } +/** + * hw_wait_reg: wait the register value + * + * Sometimes, it needs to wait register value before going on. + * Eg, when switch to device mode, the vbus value should be lower + * than OTGSC_BSV before connects to host. + * + * @ci: the controller + * @reg: register index + * @mask: mast bit + * @value: the bit value to wait + * @timeout_ms: timeout in millisecond + * + * This function returns an error code if timeout + */ +int hw_wait_reg(struct ci_hdrc *ci, enum ci_hw_regs reg, u32 mask, + u32 value, unsigned int timeout_ms) +{ + unsigned long elapse = jiffies + msecs_to_jiffies(timeout_ms); + + while (hw_read(ci, reg, mask) != value) { + if (time_after(jiffies, elapse)) { + dev_err(ci->dev, "timeout waiting for %08x in %d\n", + mask, reg); + return -ETIMEDOUT; + } + msleep(20); + } + + return 0; +} + static irqreturn_t ci_irq(int irq, void *data) { struct ci_hdrc *ci = data; |