On 9/15/25 5:48 PM, André Apitzsch wrote:
Hi Sakari,
@Val, please see below.
Am Montag, dem 18.08.2025 um 07:44 +0000 schrieb Sakari Ailus:
Hi André,
On Sun, Aug 17, 2025 at 07:09:26PM +0200, André Apitzsch via B4 Relay
wrote:
u64 val;
int ret;
int err;
@@ -109,13 +116,15 @@ 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, then
retry the write.
Why double? Isn't the datasheet correct when it comes to the power-on
sequence?
I haven't noticed any problems during power-up of DW9761. However,
according to the commit message, there seems be an issue with DW9718S.
But I don't own the device and cannot test it.
Maybe Val can provided some additional information.
I haven't had access to the datasheet for the DW9718S, so this was all
deduced experimentally. By "to be sure" I meant that I literally raised
the timeout "just in case", not based on actual issues.
The actually important change was expecting the failure on the write and
not erroring out.
Thanks,
~val
