Re: [PATCH 2/2] Input: edt-ft5x06 - add support for iovcc-supply

Hi,

On Mon, Jan 11, 2021 at 11:10:16AM +0100, Stephan Gerhold wrote:

On Mon, Jan 11, 2021 at 10:45:38AM +0100, Marco Felsch wrote:

quoted

On 21-01-11 10:26, Stephan Gerhold wrote:

quoted

On Mon, Jan 11, 2021 at 09:36:12AM +0100, Marco Felsch wrote:

quoted

On 21-01-08 20:23, Stephan Gerhold wrote:

quoted

diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c
index 2eefbc2485bc..bf2e208112fe 100644
--- a/drivers/input/touchscreen/edt-ft5x06.c
+++ b/drivers/input/touchscreen/edt-ft5x06.c

@@ -103,7 +103,7 @@ struct edt_ft5x06_ts_data {
 	struct touchscreen_properties prop;
 	u16 num_x;
 	u16 num_y;
-	struct regulator *vcc;
+	struct regulator_bulk_data regulators[2];

Is there an enabling order we must follow?

I don't know, sadly. The datasheets I was able to find do not mention
anything about this; the power-on sequence only includes the VDD line.

I've goolged a bit :)

Check this: https://focuslcds.com/content/FT5X26.pdf, page 12 of 32

Thanks! I looked at several datasheets, that's probably one of the few I
did not look at. :(

quoted

There it is mentioned that we need to enable it first and add a 10us
delay till we can enable the vdd line. So unfortunately the bulk_api
can't be used as it is today. Another solution could be to extended the
bulk api to respect on/off delays.

I think for two regulators like here it's still manageable to
get/enable/disable/put them separately, so I will just revert the bulk
API change in v2.

While implementing this I noticed that the power-up sequence in probe()
does not quite seem right. The power-up sequence implemented by Marco in
edt_ft5x06_ts_resume() seems to match the datasheet(s) but in probe() we
enable VCC before doing anything with the reset line.

So before I add the IOVCC regulator I will try to refactor the code a
bit to make this consistent. :)

Thanks,
Stephan