Re: [PATCH v8 2/3] Input: adc-joystick - Add polled input device support
From: Artur Rojek <hidden>
Date: 2022-07-28 20:26:15
Also in:
linux-iio
On 2022-07-21 18:46, Chris Morgan wrote:
From: Chris Morgan <redacted> 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 <redacted> Signed-off-by: Chris Morgan <redacted> ---
Hey Chris, sorry for the late response. Comments in-line. Cheers, Artur
quoted hunk ↗ jump to hunk
drivers/input/joystick/adc-joystick.c | 82 ++++++++++++++++++++------- 1 file changed, 62 insertions(+), 20 deletions(-)diff --git a/drivers/input/joystick/adc-joystick.cb/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(structplatform_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(structplatform_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.
+ 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.
quoted hunk ↗ jump to hunk
} } joy->num_chans = i;@@ -215,8 +247,14 @@ static int adc_joystick_probe(structplatform_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(structplatform_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;