diff options
| -rw-r--r-- | drivers/media/i2c/dw9719.c | 26 |
1 files changed, 19 insertions, 7 deletions
diff --git a/drivers/media/i2c/dw9719.c b/drivers/media/i2c/dw9719.c index a24594523030..3627e78b8b66 100644 --- a/drivers/media/i2c/dw9719.c +++ b/drivers/media/i2c/dw9719.c @@ -95,12 +95,20 @@ struct dw9719_device { static int dw9719_power_down(struct dw9719_device *dw9719) { + u32 reg_pwr = dw9719->model == DW9718S ? DW9718S_PD : DW9719_CONTROL; + + /* + * Worth engaging the internal SHUTDOWN mode especially due to the + * regulator being potentially shared with other devices. + */ + if (cci_write(dw9719->regmap, reg_pwr, DW9719_SHUTDOWN, NULL)) + dev_err(dw9719->dev, "Error writing to power register\n"); return regulator_disable(dw9719->regulator); } static int dw9719_power_up(struct dw9719_device *dw9719, bool detect) { - u32 reg_pwr; + u32 reg_pwr = dw9719->model == DW9718S ? DW9718S_PD : DW9719_CONTROL; u64 val; int ret; int err; @@ -109,13 +117,17 @@ static int dw9719_power_up(struct dw9719_device *dw9719, bool detect) if (ret) return ret; - /* Jiggle SCL pin to wake up device */ - reg_pwr = dw9719->model == DW9718S ? DW9718S_PD : DW9719_CONTROL; - cci_write(dw9719->regmap, reg_pwr, DW9719_SHUTDOWN, &ret); - fsleep(100); + /* + * Need 100us to transition from SHUTDOWN to STANDBY. + * Jiggle the SCL pin to wake up the device (even when the regulator is + * shared) and wait double the time to be sure, as 100us is not enough + * at least on the DW9718S as found on the motorola-nora smartphone, + * then retry the write. + */ + cci_write(dw9719->regmap, reg_pwr, DW9719_STANDBY, NULL); + /* the jiggle is expected to fail, don't even log that as error */ + fsleep(200); cci_write(dw9719->regmap, reg_pwr, DW9719_STANDBY, &ret); - /* Need 100us to transit from SHUTDOWN to STANDBY */ - fsleep(100); if (detect) { /* This model does not have an INFO register */ |