On 2022-06-15 17:12, Chris Morgan wrote:
On Wed, Jun 15, 2022 at 03:43:07AM +0200, Artur Rojek wrote:
On 2022-06-13 21:23, 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>
Hi Chris,
Comments inline. I also Cc'd Paul and Jonathan, who were attached in
v2.
> ---
> 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);
```
Understood. I attempted this and noticed that it was showing I have
INDIO_BUFFER_TRIGGERED in addition to INDIO_DIRECT_MODE (the
INDIO_DIRECT_MODE is the only one specified at the hardware level
though). Should I just check for INDIO_BUFFER_SOFTWARE &
INDIO_BUFFER_HARDWARE instead? I think it's possible that the inclusion
of the industrialio_triggered_buffer module in my kernel is adding
this to the channel somehow?
Having INDIO_BUFFER_TRIGGERED means that your saradc is capable of using
the existing flow. You should be able to register a software trigger and
use the adc-joystick driver without further issues.
That said, this is where it gets problematic - there is no way to create
an IIO trigger via Device Tree, since triggers don't describe any piece
of hardware, and you shouldn't need to register it at runtime
(configfs/sysfs) for communication between two kernel drivers either. At
the same time, it's not adc-joystick's job to register an external
trigger.
Jonathan,
I don't know what the proper approach to this should be, perhaps you
could assist?
Cheers,
Artur
Thank you.
> +
> + 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.
Understood, sorry about that.
> + 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.
Ditto.
Cheers,
Artur
> + if (error) {
> + dev_err(dev, "Unable to add action\n");
> + return error;
> + }
> }
>
> return 0;
