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Commit e18a2ad4 authored by Lars-Peter Clausen's avatar Lars-Peter Clausen Committed by Jonathan Cameron
Browse files

iio: Add buffer enable/disable callbacks 



This patch adds a enable and disable callback that is called when the
buffer is enabled/disabled. This can be used by buffer implementations that
need to do some setup or teardown work. E.g. a DMA based buffer can use
this to start/stop the DMA transfer.

Signed-off-by: default avatarLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent b440655b

drivers/iio/industrialio-buffer.c

+35 −1
Original line number Diff line number Diff line
@@ -568,6 +568,22 @@ static void iio_buffer_deactivate_all(struct iio_dev *indio_dev) 
		iio_buffer_deactivate(buffer);

}



static int iio_buffer_enable(struct iio_buffer *buffer,

	struct iio_dev *indio_dev)

{

	if (!buffer->access->enable)

		return 0;

	return buffer->access->enable(buffer, indio_dev);

}



static int iio_buffer_disable(struct iio_buffer *buffer,

	struct iio_dev *indio_dev)

{

	if (!buffer->access->disable)

		return 0;

	return buffer->access->disable(buffer, indio_dev);

}



static void iio_buffer_update_bytes_per_datum(struct iio_dev *indio_dev,

	struct iio_buffer *buffer)

{
@@ -719,6 +735,7 @@ static int iio_verify_update(struct iio_dev *indio_dev, 
static int iio_enable_buffers(struct iio_dev *indio_dev,

	struct iio_device_config *config)

{

	struct iio_buffer *buffer;

	int ret;



	indio_dev->active_scan_mask = config->scan_mask;
@@ -753,6 +770,12 @@ static int iio_enable_buffers(struct iio_dev *indio_dev, 
		indio_dev->info->hwfifo_set_watermark(indio_dev,

			config->watermark);



	list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {

		ret = iio_buffer_enable(buffer, indio_dev);

		if (ret)

			goto err_disable_buffers;

	}



	indio_dev->currentmode = config->mode;



	if (indio_dev->setup_ops->postenable) {
@@ -760,12 +783,16 @@ static int iio_enable_buffers(struct iio_dev *indio_dev, 
		if (ret) {

			dev_dbg(&indio_dev->dev,

			       "Buffer not started: postenable failed (%d)\n", ret);

			goto err_run_postdisable;

			goto err_disable_buffers;

		}

	}



	return 0;



err_disable_buffers:

	list_for_each_entry_continue_reverse(buffer, &indio_dev->buffer_list,

					     buffer_list)

		iio_buffer_disable(buffer, indio_dev);

err_run_postdisable:

	indio_dev->currentmode = INDIO_DIRECT_MODE;

	if (indio_dev->setup_ops->postdisable)
@@ -778,6 +805,7 @@ static int iio_enable_buffers(struct iio_dev *indio_dev, 


static int iio_disable_buffers(struct iio_dev *indio_dev)

{

	struct iio_buffer *buffer;

	int ret = 0;

	int ret2;
@@ -798,6 +826,12 @@ static int iio_disable_buffers(struct iio_dev *indio_dev) 
			ret = ret2;

	}



	list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {

		ret2 = iio_buffer_disable(buffer, indio_dev);

		if (ret2 && !ret)

			ret = ret2;

	}



	indio_dev->currentmode = INDIO_DIRECT_MODE;



	if (indio_dev->setup_ops->postdisable) {

include/linux/iio/buffer.h

+8 −0
Original line number Diff line number Diff line
@@ -33,6 +33,11 @@ struct iio_buffer; 
 *			storage.

 * @set_bytes_per_datum:set number of bytes per datum

 * @set_length:		set number of datums in buffer

 * @enable:             called if the buffer is attached to a device and the

 *                      device starts sampling. Calls are balanced with

 *                      @disable.

 * @disable:            called if the buffer is attached to a device and the

 *                      device stops sampling. Calles are balanced with @enable.

 * @release:		called when the last reference to the buffer is dropped,

 *			should free all resources allocated by the buffer.

 * @modes:		Supported operating modes by this buffer type
@@ -58,6 +63,9 @@ struct iio_buffer_access_funcs { 
	int (*set_bytes_per_datum)(struct iio_buffer *buffer, size_t bpd);

	int (*set_length)(struct iio_buffer *buffer, int length);



	int (*enable)(struct iio_buffer *buffer, struct iio_dev *indio_dev);

	int (*disable)(struct iio_buffer *buffer, struct iio_dev *indio_dev);



	void (*release)(struct iio_buffer *buffer);



	unsigned int modes;