On Thu, Jul 28, 2022 at 10:26:07PM +0200, Artur Rojek wrote:
> On 2022-07-21 18:46, Chris Morgan wrote:
> > From: Chris Morgan <macromorgan@xxxxxxxxxxx>
> >
> > 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@xxxxxxxxx>
> > Signed-off-by: Chris Morgan <macromorgan@xxxxxxxxxxx>
> > ---
> Hey Chris,
>
> sorry for the late response. Comments in-line.
>
> Cheers,
> Artur
> > drivers/input/joystick/adc-joystick.c | 82 ++++++++++++++++++++-------
> > 1 file changed, 62 insertions(+), 20 deletions(-)
> >
> > diff --git a/drivers/input/joystick/adc-joystick.c
> > b/drivers/input/joystick/adc-joystick.c
> > index 78ebca7d400a..085b8e10dfb5 100644
> > --- a/drivers/input/joystick/adc-joystick.c
> > +++ b/drivers/input/joystick/adc-joystick.c
> > @@ -26,8 +26,23 @@ 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, ret;
> > +
> > + for (i = 0; i < joy->num_chans; i++) {
> > + ret = iio_read_channel_raw(&joy->chans[i], &val);
> > + if (ret < 0)
> > + return;
> > + 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;
> > @@ -178,7 +193,9 @@ static int adc_joystick_probe(struct platform_device
> > *pdev)
> > struct input_dev *input;
> > int error;
> > int bits;
> > + int chan_storage;
> > int i;
> > + unsigned int poll_interval;
> >
> > joy = devm_kzalloc(dev, sizeof(*joy), GFP_KERNEL);
> > if (!joy)
> > @@ -192,16 +209,31 @@ static int adc_joystick_probe(struct
> > platform_device *pdev)
> > return error;
> > }
> >
> > - /* Count how many channels we got. NULL terminated. */
> > + if (device_property_present(dev, "poll-interval")) {
> > + error = device_property_read_u32(dev, "poll-interval",
> > + &poll_interval);
> > + if (error)
> > + return error;
> > + joy->polled = true;
> > + }
> > +
> > + /* Count how many channels we got. NULL terminated. Do not check the
> > + * storage size if using polling.
> > + */
> As per Linux coding style, the multi-line comment opens with a lone `/*`
> line. Also, move the second sentence into a new line for readability.
Gotcha, I always thought it could start this way but had to end with an
empty line. I guess I learned something new.
>
> > + chan_storage = joy->chans[0].channel->scan_type.storagebits;
> > for (i = 0; joy->chans[i].indio_dev; i++) {
> > - bits = joy->chans[i].channel->scan_type.storagebits;
> > - if (!bits || bits > 16) {
> > - dev_err(dev, "Unsupported channel storage size\n");
> > - return -EINVAL;
> > - }
> > - if (bits != joy->chans[0].channel->scan_type.storagebits) {
> > - dev_err(dev, "Channels must have equal storage size\n");
> > - return -EINVAL;
> > + if (!joy->polled) {
> > + bits = joy->chans[i].channel->scan_type.storagebits;
> > + if (!bits || bits > 16) {
> > + dev_err(dev,
> > + "Unsupported channel storage size\n");
> > + return -EINVAL;
> > + }
> > + if (bits != chan_storage) {
> > + dev_err(dev,
> > + "Channels must be equal size\n");
> > + return -EINVAL;
> > + }
> Just do `for (i = 0; !joy->polled && joy->chans[i].indio_dev; i++)`, as
> this will terminate early if we're polling.
> Then we'll also be able to restore the loop body to its original code and
> get rid of that `chan_storage` helper.
>
Thank you, I was struggling to figure out how to get the code to do
what I wanted while keeping it below 80 columns, this is perfect.
> > }
> > }
> > joy->num_chans = i;
> > @@ -215,8 +247,14 @@ 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 (joy->polled) {
> > + input_setup_polling(input, adc_joystick_poll);
> > + input_set_poll_interval(input, poll_interval);
> > + } else {
> > + input->open = adc_joystick_open;
> > + input->close = adc_joystick_close;
> > + }
> >
> > error = adc_joystick_set_axes(dev, joy);
> > if (error)
> > @@ -229,16 +267,20 @@ 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);
> > + 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);
> > + if (error) {
> > + dev_err(dev, "Unable to add action\n");
> > + return error;
> > + }
> > }
> >
> > return 0;
>
