On Fri, Dec 08, 2017 at 05:16:29PM -0800, Dmitry Torokhov wrote:
> Hi Mylène,
>
> On Fri, Dec 08, 2017 at 10:54:18PM +0100, Mylène Josserand wrote:
> > Add the support of regulator to use them as VCC source.
> >
> > Signed-off-by: Mylène Josserand <mylene.josserand@xxxxxxxxxxxxxxxxxx>
> > ---
> > drivers/input/touchscreen/edt-ft5x06.c | 33 +++++++++++++++++++++++++++++++++
> > 1 file changed, 33 insertions(+)
> >
> > diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c
> > index c53a3d7239e7..44b0e04a8f35 100644
> > --- a/drivers/input/touchscreen/edt-ft5x06.c
> > +++ b/drivers/input/touchscreen/edt-ft5x06.c
> > @@ -39,6 +39,7 @@
> > #include <linux/input/mt.h>
> > #include <linux/input/touchscreen.h>
> > #include <linux/of_device.h>
> > +#include <linux/regulator/consumer.h>
> >
> > #define WORK_REGISTER_THRESHOLD 0x00
> > #define WORK_REGISTER_REPORT_RATE 0x08
> > @@ -91,6 +92,7 @@ struct edt_ft5x06_ts_data {
> > struct touchscreen_properties prop;
> > u16 num_x;
> > u16 num_y;
> > + struct regulator *supply;
> >
> > struct gpio_desc *reset_gpio;
> > struct gpio_desc *wake_gpio;
> > @@ -993,6 +995,23 @@ static int edt_ft5x06_ts_probe(struct i2c_client *client,
> >
> > tsdata->max_support_points = chip_data->max_support_points;
> >
> > + tsdata->supply = devm_regulator_get_optional(&client->dev, "power");
>
> I'd prefer if we used devm_regulator_get() instead. On a
> fully-constrained systems a missing regulator will be substituted with a
> dummy one that you can then use in regulator_enable() and
> regulator_disable(). The _optional regulator API is reserved for cases
> where some of chip functionality is optional and you can engage it by
> powering up parts of the chip. The reset is not such case: it is always
> present, but may not be exposed to the OS to control.
>
> I think the preference is to call the supply by the name is a datasheet,
> something like "vcc" or "vdd", etc.
Looking at this some more, you need to make sure your new regulator
support plays well with reset/wake GPIOs. I.e. you probably want to
properly bring the chip out of reset in edt_ft5x06_ts_resume() and maybe
driver the reset line low in suspend to make sure you do not leak into
the unpowered chip?
Also, please update
Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt with
the additional binding data and cc device tree folks and Rob Herring.
Thanks.
--
Dmitry
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