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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; |