[PATCH v2 1/2] Input: edt-ft5x06 - Add support for regulator

Mylene Josserand
2018-01-26T10:11:54Z

Hello Dmitry,

Le Tue, 23 Jan 2018 09:58:29 -0800,
Dmitry Torokhov <dmitry.torokhov@gmail.com> a ?crit :

> On Tue, Jan 23, 2018 at 10:10:55AM +0100, Mylene Josserand wrote:
> > Hello Dimitry,
> >
> > Thank you for the review!
> >
> > Le Mon, 22 Jan 2018 09:42:08 -0800,
> > Dmitry Torokhov <dmitry.torokhov@gmail.com> a ?crit :
> >
> > > Hi Myl?ne,
> > >
> > > On Thu, Dec 28, 2017 at 8:33 AM, Myl?ne Josserand
> > > <mylene.josserand@free-electrons.com> wrote:
> > > > Add the support of regulator to use it as VCC source.
> > > >
> > > > Signed-off-by: Myl?ne Josserand <mylene.josserand@free-electrons.com>
> > > > ---
> > > > .../bindings/input/touchscreen/edt-ft5x06.txt | 1 +
> > > > drivers/input/touchscreen/edt-ft5x06.c | 33 ++++++++++++++++++++++
> > > > 2 files changed, 34 insertions(+)
> > > >
> > > > diff --git a/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt b/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt
> > > > index 025cf8c9324a..48e975b9c1aa 100644
> > > > --- a/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt
> > > > +++ b/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt
> > > > @@ -30,6 +30,7 @@ Required properties:
> > > > Optional properties:
> > > > - reset-gpios: GPIO specification for the RESET input
> > > > - wake-gpios: GPIO specification for the WAKE input
> > > > + - vcc-supply: Regulator that supplies the touchscreen
> > > >
> > > > - pinctrl-names: should be "default"
> > > > - pinctrl-0: a phandle pointing to the pin settings for the
> > > > diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c
> > > > index c53a3d7239e7..5ee14a25a382 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 *vcc;
> > > >
> > > > 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->vcc = devm_regulator_get(&client->dev, "vcc");
> > > > + if (IS_ERR(tsdata->vcc)) {
> > > > + error = PTR_ERR(tsdata->vcc);
> > > > + dev_err(&client->dev, "failed to request regulator: %d\n",
> > > > + error);
> > > > + return error;
> > > > + };
> > >
> > > As 0-day pounted out, this semicolon is not needed.
> >
> > Yes, thanks, I will fix that in next version.
> >
> > >
> > > > +
> > > > + if (tsdata->vcc) {
> > >
> > > You do not need to check for non-NULL here, devm_regulator_get() wil
> > > lnever give you a NULL. If regulator is not defined in DT/board
> > > mappings, then dummy regulator will be provided. You can call
> > > regulator_enable() and regulator_disable() and other regulator APIs
> > > with dummy regulator.
> >
> > Okay, thanks for the explanation, I will remove that.
> >
> > >
> > > > + error = regulator_enable(tsdata->vcc);
> > > > + if (error < 0) {
> > > > + dev_err(&client->dev, "failed to enable vcc: %d\n",
> > > > + error);
> > > > + return error;
> > > > + }
> > > > + }
> > > > +
> > > > tsdata->reset_gpio = devm_gpiod_get_optional(&client->dev,
> > > > "reset", GPIOD_OUT_HIGH);
> > > > if (IS_ERR(tsdata->reset_gpio)) {
> > > > @@ -1122,20 +1141,34 @@ static int edt_ft5x06_ts_remove(struct i2c_client *client)
> > > > static int __maybe_unused edt_ft5x06_ts_suspend(struct device *dev)
> > > > {
> > > > struct i2c_client *client = to_i2c_client(dev);
> > > > + struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
> > > >
> > > > if (device_may_wakeup(dev))
> > > > enable_irq_wake(client->irq);
> > > >
> > > > + if (tsdata->vcc)
> > >
> > > Same here.
> >
> > yep
> >
> > >
> > > > + regulator_disable(tsdata->vcc);
> > > > +
> > > > return 0;
> > > > }
> > > >
> > > > static int __maybe_unused edt_ft5x06_ts_resume(struct device *dev)
> > > > {
> > > > struct i2c_client *client = to_i2c_client(dev);
> > > > + struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
> > > > + int ret;
> > > >
> > > > if (device_may_wakeup(dev))
> > > > disable_irq_wake(client->irq);
> > > >
> > > > + if (tsdata->vcc) {
> > >
> > > And here.
> >
> > yep
> >
> > >
> > > > + ret = regulator_enable(tsdata->vcc);
> > > > + if (ret < 0) {
> > > > + dev_err(dev, "failed to enable vcc: %d\n", ret);
> > > > + return ret;
> > > > + }
> > >
> > > Since power to the device may have been cut, I think you need to
> > > restore the register settings to whatever it was (factory vs work
> > > mode, threshold, gain and offset registers, etc, etc).
> >
> > Okay. Could you tell me how can I do that?
>
> If you take a look at edt_ft5x06_work_mode() at the end ther eis code to
> restore parameters. You want to factor it out and apply to the device
> when resuming. You probably also want to see what mode (factory/normal)
> the device was before suspend and restore the previous mode on resume.

Okay, thank you for your help.

About the factory/normal mode to be sure that I understand correctly,
in the resume, I should use something like "edt_ft5x06_debugfs_mode_set"
to check the "tsdata->factory_mode" and call "edt_ft5x06_factory_mode"
or "edt_ft5x06_work_mode", is not it?

As the current suspend/resume code is only enabling/disabling an irq, I
would like to understand exactly the modifications you would like.

>
> >
> > >
> > > > + }
> > > > +
> > > > return 0;
> > > > }
> > > >
> > > > --
> > > > 2.11.0
> > > >
> > >
> > > Thanks.
> > >
> >
> > About your V2's review, you suggested to add support for wake/reset in
> > suspend/resume (that I forgot in this version). I wanted to add it but
> > with my board, I can't test suspend/resume. What should I do about
> > that?
>
> See if Simon Budig <simon.budig@kernelconcepts.de> can help us here.

Thank you, I contacted Simon (added him in CC) and unfortunately, he
doesn't have a setup with working suspend/resume so he can't help me
on that.
My patches are ready (except for factory/normal mode, see above) but as
I can't test suspend/resume, I prefer not to send them without testing
it..

>
> >
> > If I send a V3 in next few days, do you think you will have time to
> > merge it for v4.16?
>
> It all depends on the patch shape...

Sure I understand.

Best regards,

--
Myl?ne Josserand, Free Electrons
Embedded Linux and Kernel engineering