Re: [PATCH v3 2/3] Input: adc-joystick - Add polled input device support

Jonathan Cameron
2022-06-19T15:10:03Z

On Wed, 15 Jun 2022 03:43:07 +0200
Artur Rojek <contact@artur-rojek.eu> wrote:

> On 2022-06-13 21:23, Chris Morgan wrote:
> > From: Chris Morgan <macromorgan@hotmail.com>
> >
> > Add polled input device support to the adc-joystick driver. This is
> > useful for devices which do not have hardware capable triggers on
> > their SARADC. Code modified from adc-joystick.c changes made by Maya
> > Matuszczyk.
> >
> > Signed-off-by: Maya Matuszczyk <maccraft123mc@gmail.com>
> > Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
>
> Hi Chris,
>
> Comments inline. I also Cc'd Paul and Jonathan, who were attached in v2.

Please cc linux-iio@vger.kernel.org on future versions.

>
> > ---
> > drivers/input/joystick/adc-joystick.c | 52 +++++++++++++++++++++------
> > 1 file changed, 41 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/input/joystick/adc-joystick.c
> > b/drivers/input/joystick/adc-joystick.c
> > index 78ebca7d400a..dc01cd0214d2 100644
> > --- a/drivers/input/joystick/adc-joystick.c
> > +++ b/drivers/input/joystick/adc-joystick.c
> > @@ -13,6 +13,10 @@
> >
> > #include <asm/unaligned.h>
> >
> > +#define ADC_JSK_POLL_INTERVAL 16
> > +#define ADC_JSK_POLL_MIN 8
> > +#define ADC_JSK_POLL_MAX 32
> > +
> > struct adc_joystick_axis {
> > u32 code;
> > s32 range[2];
> > @@ -26,8 +30,21 @@ struct adc_joystick {
> > struct adc_joystick_axis *axes;
> > struct iio_channel *chans;
> > int num_chans;
> > + bool polled;
> > };
> >
> > +static void adc_joystick_poll(struct input_dev *input)
> > +{
> > + struct adc_joystick *joy = input_get_drvdata(input);
> > + int i, val;
> > +
> > + for (i = 0; i < joy->num_chans; i++) {
> > + iio_read_channel_raw(&joy->chans[i], &val);
> > + input_report_abs(input, joy->axes[i].code, val);
> > + }
> > + input_sync(input);
> > +}
> > +
> > static int adc_joystick_handle(const void *data, void *private)
> > {
> > struct adc_joystick *joy = private;
> > @@ -215,8 +232,19 @@ static int adc_joystick_probe(struct
> > platform_device *pdev)
> > joy->input = input;
> > input->name = pdev->name;
> > input->id.bustype = BUS_HOST;
> > - input->open = adc_joystick_open;
> > - input->close = adc_joystick_close;
> > +
> > + if (device_property_read_bool(dev,
> > "adc-joystick,no-hardware-trigger"))
> > + joy->polled = 1;
> As mentioned in v2, I don't think a DT property is required here.
> Assuming the polled mode is a fallback for devices with no buffers, just
> do:
> ```
> joy->polled = !(joy->chans[0].indio_dev->modes &
> INDIO_ALL_BUFFER_MODES);
> ```
> > +
> > + if (joy->polled) {
> > + input_setup_polling(input, adc_joystick_poll);
> > + input_set_poll_interval(input, ADC_JSK_POLL_INTERVAL);
> > + input_set_min_poll_interval(input, ADC_JSK_POLL_MIN);
> > + input_set_max_poll_interval(input, ADC_JSK_POLL_MAX);
> > + } else {
> > + input->open = adc_joystick_open;
> > + input->close = adc_joystick_close;
> > + }
> >
> > error = adc_joystick_set_axes(dev, joy);
> > if (error)
> > @@ -229,16 +257,18 @@ static int adc_joystick_probe(struct
> > platform_device *pdev)
> > return error;
> > }
> >
> > - joy->buffer = iio_channel_get_all_cb(dev, adc_joystick_handle, joy);
> > - if (IS_ERR(joy->buffer)) {
> > - dev_err(dev, "Unable to allocate callback buffer\n");
> > - return PTR_ERR(joy->buffer);
> > - }
> > + if (!joy->polled) {
> > + joy->buffer = iio_channel_get_all_cb(dev, adc_joystick_handle, joy);
> Please maintain line discipline of 80 chars to stay consistent with the
> rest of this driver.
> > + if (IS_ERR(joy->buffer)) {
> > + dev_err(dev, "Unable to allocate callback buffer\n");
> > + return PTR_ERR(joy->buffer);
> > + }
> >
> > - error = devm_add_action_or_reset(dev, adc_joystick_cleanup,
> > joy->buffer);
> > - if (error) {
> > - dev_err(dev, "Unable to add action\n");
> > - return error;
> > + error = devm_add_action_or_reset(dev, adc_joystick_cleanup,
> > joy->buffer);
> Same here.
>
> Cheers,
> Artur
> > + if (error) {
> > + dev_err(dev, "Unable to add action\n");
> > + return error;
> > + }
> > }
> >
> > return 0;