Re: [PATCH v2 2/3] Input: adc-joystick - Add polled input device support
From: Paul Cercueil <paul@crapouillou.net>
Date: 2022-06-02 09:22:29
Also in:
linux-devicetree
Hi Chris, Le mer., juin 1 2022 at 15:49:26 -0500, Chris Morgan [off-list ref] a écrit :
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.
I understand what you're trying to do, but maybe there's a better way. It would be better if pollable IIO devices would also be able to be used with a buffer, with the client driver manually triggering the IIO device through a function call. Jonathan (Cc'd) might have his reasons why this isn't done this way, and in this case your patch makes sense, but I'd like to hear Jonathan's thoughts first. As for "adc-joystick,polled"... it doesn't describe the hardware but rather a specific configuration, so it shouldn't appear in the device tree. Cheers, -Paul
quoted hunk ↗ jump to hunk
Signed-off-by: Maya Matuszczyk <redacted> Signed-off-by: Chris Morgan <redacted> --- drivers/input/joystick/adc-joystick.c | 52 +++++++++++++++++++++------ 1 file changed, 41 insertions(+), 11 deletions(-)diff --git a/drivers/input/joystick/adc-joystick.cb/drivers/input/joystick/adc-joystick.c index 78ebca7d400a..5a28fe7b8ebc 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(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 (device_property_read_bool(dev, "adc-joystick,polled")) + joy->polled = 1; + + 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(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;