On Fri, Jul 29, 2022 at 11:30:51AM -0500, Chris Morgan wrote:
> 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.
The suggested code doesn't work (because it doesn't count the channels, however
it gave me an idea to include a check in each of the if conditions below it to
look for joy->polled, and I think that works. I'll send v9 shortly. Thank you
for all your help.
>
> > > }
> > > }
> > > 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;
> >
