diff options
Diffstat (limited to 'drivers/iio/dummy/iio_simple_dummy_buffer.c')
| -rw-r--r-- | drivers/iio/dummy/iio_simple_dummy_buffer.c | 161 |
1 files changed, 45 insertions, 116 deletions
diff --git a/drivers/iio/dummy/iio_simple_dummy_buffer.c b/drivers/iio/dummy/iio_simple_dummy_buffer.c index 17606eca42b4..e35e0596cbfb 100644 --- a/drivers/iio/dummy/iio_simple_dummy_buffer.c +++ b/drivers/iio/dummy/iio_simple_dummy_buffer.c @@ -1,5 +1,5 @@ // SPDX-License-Identifier: GPL-2.0-only -/** +/* * Copyright (c) 2011 Jonathan Cameron * * Buffer handling elements of industrial I/O reference driver. @@ -16,9 +16,9 @@ #include <linux/bitmap.h> #include <linux/iio/iio.h> -#include <linux/iio/trigger_consumer.h> #include <linux/iio/buffer.h> -#include <linux/iio/kfifo_buf.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> #include "iio_simple_dummy.h" @@ -31,6 +31,11 @@ static const s16 fakedata[] = { [DUMMY_INDEX_ACCELX] = 344, }; +struct dummy_scan { + s16 data[ARRAY_SIZE(fakedata)]; + aligned_s64 timestamp; +}; + /** * iio_simple_dummy_trigger_h() - the trigger handler function * @irq: the interrupt number @@ -45,49 +50,43 @@ static irqreturn_t iio_simple_dummy_trigger_h(int irq, void *p) { struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; - int len = 0; - u16 *data; + struct dummy_scan *scan; + int i = 0, j; - data = kmalloc(indio_dev->scan_bytes, GFP_KERNEL); - if (!data) + /* + * Note that some buses such as SPI require DMA safe buffers which + * cannot be on the stack. Two easy ways to do this: + * - Local kzalloc (as done here) + * - A buffer at the end of the structure accessed via iio_priv() + * that is marked __aligned(IIO_DMA_MINALIGN). + */ + scan = kzalloc(sizeof(*scan), GFP_KERNEL); + if (!scan) goto done; - if (!bitmap_empty(indio_dev->active_scan_mask, indio_dev->masklength)) { - /* - * Three common options here: - * hardware scans: certain combinations of channels make - * up a fast read. The capture will consist of all of them. - * Hence we just call the grab data function and fill the - * buffer without processing. - * software scans: can be considered to be random access - * so efficient reading is just a case of minimal bus - * transactions. - * software culled hardware scans: - * occasionally a driver may process the nearest hardware - * scan to avoid storing elements that are not desired. This - * is the fiddliest option by far. - * Here let's pretend we have random access. And the values are - * in the constant table fakedata. - */ - int i, j; - - for (i = 0, j = 0; - i < bitmap_weight(indio_dev->active_scan_mask, - indio_dev->masklength); - i++, j++) { - j = find_next_bit(indio_dev->active_scan_mask, - indio_dev->masklength, j); - /* random access read from the 'device' */ - data[i] = fakedata[j]; - len += 2; - } - } - - iio_push_to_buffers_with_timestamp(indio_dev, data, - iio_get_time_ns(indio_dev)); + /* + * Three common options here: + * hardware scans: + * certain combinations of channels make up a fast read. The capture + * will consist of all of them. Hence we just call the grab data + * function and fill the buffer without processing. + * software scans: + * can be considered to be random access so efficient reading is just + * a case of minimal bus transactions. + * software culled hardware scans: + * occasionally a driver may process the nearest hardware scan to avoid + * storing elements that are not desired. This is the fiddliest option + * by far. + * Here let's pretend we have random access. And the values are in the + * constant table fakedata. + */ + iio_for_each_active_channel(indio_dev, j) + scan->data[i++] = fakedata[j]; - kfree(data); + iio_push_to_buffers_with_ts(indio_dev, scan, sizeof(*scan), + iio_get_time_ns(indio_dev)); + kfree(scan); done: /* * Tell the core we are done with this trigger and ready for the @@ -99,90 +98,20 @@ done: } static const struct iio_buffer_setup_ops iio_simple_dummy_buffer_setup_ops = { - /* - * iio_triggered_buffer_postenable: - * Generic function that simply attaches the pollfunc to the trigger. - * Replace this to mess with hardware state before we attach the - * trigger. - */ - .postenable = &iio_triggered_buffer_postenable, - /* - * iio_triggered_buffer_predisable: - * Generic function that simple detaches the pollfunc from the trigger. - * Replace this to put hardware state back again after the trigger is - * detached but before userspace knows we have disabled the ring. - */ - .predisable = &iio_triggered_buffer_predisable, }; int iio_simple_dummy_configure_buffer(struct iio_dev *indio_dev) { - int ret; - struct iio_buffer *buffer; - - /* Allocate a buffer to use - here a kfifo */ - buffer = iio_kfifo_allocate(); - if (!buffer) { - ret = -ENOMEM; - goto error_ret; - } - - iio_device_attach_buffer(indio_dev, buffer); - - /* - * Tell the core what device type specific functions should - * be run on either side of buffer capture enable / disable. - */ - indio_dev->setup_ops = &iio_simple_dummy_buffer_setup_ops; - - /* - * Configure a polling function. - * When a trigger event with this polling function connected - * occurs, this function is run. Typically this grabs data - * from the device. - * - * NULL for the bottom half. This is normally implemented only if we - * either want to ping a capture now pin (no sleeping) or grab - * a timestamp as close as possible to a data ready trigger firing. - * - * IRQF_ONESHOT ensures irqs are masked such that only one instance - * of the handler can run at a time. - * - * "iio_simple_dummy_consumer%d" formatting string for the irq 'name' - * as seen under /proc/interrupts. Remaining parameters as per printk. - */ - indio_dev->pollfunc = iio_alloc_pollfunc(NULL, - &iio_simple_dummy_trigger_h, - IRQF_ONESHOT, - indio_dev, - "iio_simple_dummy_consumer%d", - indio_dev->id); - - if (!indio_dev->pollfunc) { - ret = -ENOMEM; - goto error_free_buffer; - } - - /* - * Notify the core that this device is capable of buffered capture - * driven by a trigger. - */ - indio_dev->modes |= INDIO_BUFFER_TRIGGERED; - - return 0; - -error_free_buffer: - iio_kfifo_free(indio_dev->buffer); -error_ret: - return ret; + return iio_triggered_buffer_setup(indio_dev, NULL, + iio_simple_dummy_trigger_h, + &iio_simple_dummy_buffer_setup_ops); } /** * iio_simple_dummy_unconfigure_buffer() - release buffer resources - * @indo_dev: device instance state + * @indio_dev: device instance state */ void iio_simple_dummy_unconfigure_buffer(struct iio_dev *indio_dev) { - iio_dealloc_pollfunc(indio_dev->pollfunc); - iio_kfifo_free(indio_dev->buffer); + iio_triggered_buffer_cleanup(indio_dev); } |