[PATCH v3 01/11] iio: Add hardware consumer support

[Arnaud Pouliquen]

Hello Lars,

Any news on the upstream of your HW consumer interface, prerequisite for
my STM32 DFSDM upstream?
Don't hesitate if i can help...

Regards
Arnaud


On 03/17/2017 03:08 PM, Arnaud POULIQUEN wrote:
> From: Lars-Peter Clausen <lars at metafoo.de>
> 
> Hardware consumer's can be used when one IIO device has a direct connection
> to another device in hardware.
> 
> Signed-off-by: Lars-Peter Clausen <lars at metafoo.de>
> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen at st.com>
> ---
> V2 -> V3:
> 	 Just Adding sign off.  No update but Jonathan comment.
>          Need to be taken into account (in agreement with Lars)
>          when transforming rfc in patch.
> ---
>  drivers/iio/Kconfig             |   6 ++
>  drivers/iio/Makefile            |   1 +
>  drivers/iio/hw_consumer.c       | 156 ++++++++++++++++++++++++++++++++++++++++
>  include/linux/iio/hw_consumer.h |  12 ++++
>  4 files changed, 175 insertions(+)
>  create mode 100644 drivers/iio/hw_consumer.c
>  create mode 100644 include/linux/iio/hw_consumer.h
> 
> diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig
> index 6743b18..956dd18 100644
> --- a/drivers/iio/Kconfig
> +++ b/drivers/iio/Kconfig
> @@ -30,6 +30,12 @@ config IIO_CONFIGFS
>  	  (e.g. software triggers). For more info see
>  	  Documentation/iio/iio_configfs.txt.
>  
> +config IIO_HW_CONSUMER
> +	tristate
> +	help
> +	  Hardware consumer buffer
> +
> +
>  config IIO_TRIGGER
>  	bool "Enable triggered sampling support"
>  	help
> diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile
> index 87e4c43..8472b97 100644
> --- a/drivers/iio/Makefile
> +++ b/drivers/iio/Makefile
> @@ -6,6 +6,7 @@ obj-$(CONFIG_IIO) += industrialio.o
>  industrialio-y := industrialio-core.o industrialio-event.o inkern.o
>  industrialio-$(CONFIG_IIO_BUFFER) += industrialio-buffer.o
>  industrialio-$(CONFIG_IIO_TRIGGER) += industrialio-trigger.o
> +obj-$(CONFIG_IIO_HW_CONSUMER) += hw_consumer.o
>  
>  obj-$(CONFIG_IIO_CONFIGFS) += industrialio-configfs.o
>  obj-$(CONFIG_IIO_SW_DEVICE) += industrialio-sw-device.o
> diff --git a/drivers/iio/hw_consumer.c b/drivers/iio/hw_consumer.c
> new file mode 100644
> index 0000000..66f0732
> --- /dev/null
> +++ b/drivers/iio/hw_consumer.c
> @@ -0,0 +1,156 @@
> +#include <linux/err.h>
> +#include <linux/export.h>
> +#include <linux/slab.h>
> +#include <linux/mutex.h>
> +#include <linux/of.h>
> +
> +#include <linux/iio/iio.h>
> +#include "iio_core.h"
> +#include <linux/iio/machine.h>
> +#include <linux/iio/driver.h>
> +#include <linux/iio/consumer.h>
> +#include <linux/iio/hw_consumer.h>
> +#include <linux/iio/buffer.h>
> +
> +struct iio_hw_consumer {
> +	struct list_head buffers;
> +	struct iio_channel *channels;
> +};
> +
> +struct hw_consumer_buffer {
> +	struct list_head head;
> +	struct iio_dev *indio_dev;
> +	struct iio_buffer buffer;
> +};
> +
> +static struct hw_consumer_buffer *iio_buffer_to_hw_consumer_buffer(
> +	struct iio_buffer *buffer)
> +{
> +	return container_of(buffer, struct hw_consumer_buffer, buffer);
> +}
> +
> +static void iio_hw_buf_release(struct iio_buffer *buffer)
> +{
> +	struct hw_consumer_buffer *hw_buf =
> +		iio_buffer_to_hw_consumer_buffer(buffer);
> +	kfree(hw_buf->buffer.scan_mask);
> +	kfree(hw_buf);
> +}
> +
> +static const struct iio_buffer_access_funcs iio_hw_buf_access = {
> +	.release = &iio_hw_buf_release,
> +	.modes = INDIO_BUFFER_HARDWARE,
> +};
> +
> +static struct hw_consumer_buffer *iio_hw_consumer_get_buffer(
> +	struct iio_hw_consumer *hwc, struct iio_dev *indio_dev)
> +{
> +	struct hw_consumer_buffer *buf;
> +
> +	list_for_each_entry(buf, &hwc->buffers, head) {
> +		if (buf->indio_dev == indio_dev)
> +			return buf;
> +	}
> +
> +	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
> +	if (!buf)
> +		return NULL;
> +
> +	buf->buffer.access = &iio_hw_buf_access;
> +	buf->indio_dev = indio_dev;
> +	buf->buffer.scan_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength),
> +		sizeof(long), GFP_KERNEL);
> +	if (!buf->buffer.scan_mask)
> +		goto err_free_buf;
> +
> +	iio_buffer_init(&buf->buffer);
> +	list_add_tail(&buf->head, &hwc->buffers);
> +
> +	return buf;
> +
> +err_free_buf:
> +	kfree(buf);
> +	return NULL;
> +}
> +
> +struct iio_hw_consumer *iio_hw_consumer_alloc(struct device *dev)
> +{
> +	struct hw_consumer_buffer *buf;
> +	struct iio_hw_consumer *hwc;
> +	struct iio_channel *chan;
> +	int ret;
> +
> +	hwc = kzalloc(sizeof(*hwc), GFP_KERNEL);
> +	if (!hwc)
> +		return ERR_PTR(-ENOMEM);
> +
> +	INIT_LIST_HEAD(&hwc->buffers);
> +
> +	hwc->channels = iio_channel_get_all(dev);
> +	if (IS_ERR(hwc->channels)) {
> +		ret = PTR_ERR(hwc->channels);
> +		goto err_free_hwc;
> +	}
> +
> +	chan = &hwc->channels[0];
> +	while (chan->indio_dev) {
> +		buf = iio_hw_consumer_get_buffer(hwc, chan->indio_dev);
> +		if (buf == NULL) {
> +			ret = -ENOMEM;
> +			goto err_put_buffers;
> +		}
> +		set_bit(chan->channel->scan_index, buf->buffer.scan_mask);
> +		chan++;
> +	}
> +
> +	return hwc;
> +
> +err_put_buffers:
> +	list_for_each_entry(buf, &hwc->buffers, head)
> +		iio_buffer_put(&buf->buffer);
> +	iio_channel_release_all(hwc->channels);
> +err_free_hwc:
> +	kfree(hwc);
> +	return ERR_PTR(ret);
> +}
> +EXPORT_SYMBOL_GPL(iio_hw_consumer_alloc);
> +
> +void iio_hw_consumer_free(struct iio_hw_consumer *hwc)
> +{
> +	struct hw_consumer_buffer *buf;
> +
> +	iio_channel_release_all(hwc->channels);
> +	list_for_each_entry(buf, &hwc->buffers, head)
> +		iio_buffer_put(&buf->buffer);
> +	kfree(hwc);
> +}
> +EXPORT_SYMBOL_GPL(iio_hw_consumer_free);
> +
> +int iio_hw_consumer_enable(struct iio_hw_consumer *hwc)
> +{
> +	struct hw_consumer_buffer *buf;
> +	int ret;
> +
> +	list_for_each_entry(buf, &hwc->buffers, head) {
> +		ret = iio_update_buffers(buf->indio_dev, &buf->buffer, NULL);
> +		if (ret)
> +			goto err_disable_buffers;
> +	}
> +
> +	return 0;
> +
> +err_disable_buffers:
> +	list_for_each_entry_continue_reverse(buf, &hwc->buffers, head)
> +		iio_update_buffers(buf->indio_dev, NULL, &buf->buffer);
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(iio_hw_consumer_enable);
> +
> +void iio_hw_consumer_disable(struct iio_hw_consumer *hwc)
> +{
> +	struct hw_consumer_buffer *buf;
> +
> +	list_for_each_entry(buf, &hwc->buffers, head)
> +		iio_update_buffers(buf->indio_dev, NULL, &buf->buffer);
> +}
> +EXPORT_SYMBOL_GPL(iio_hw_consumer_disable);
> diff --git a/include/linux/iio/hw_consumer.h b/include/linux/iio/hw_consumer.h
> new file mode 100644
> index 0000000..f12653d
> --- /dev/null
> +++ b/include/linux/iio/hw_consumer.h
> @@ -0,0 +1,12 @@
> +#ifndef LINUX_IIO_HW_CONSUMER_BUFFER_H
> +#define LINUX_IIO_HW_CONSUMER_BUFFER_H
> +
> +struct device;
> +struct iio_hw_consumer;
> +
> +struct iio_hw_consumer *iio_hw_consumer_alloc(struct device *dev);
> +void iio_hw_consumer_free(struct iio_hw_consumer *hwc);
> +int iio_hw_consumer_enable(struct iio_hw_consumer *hwc);
> +void iio_hw_consumer_disable(struct iio_hw_consumer *hwc);
> +
> +#endif
>