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

[Arnaud Pouliquen <arnaud.pouliquen@st.com>]

Hello Lars,

New gentlemen Reminder.

I suppose that you have to treat a lot of subjects with more priority
than this one, but on my side I'm starting to have a lot of pressure
from project, as STM32 DFSDM upstream is blocked since close to 6 months.

As you proposed the interface, I would be fair you could push it for
upstream this month.

If you don't have time for this, another solution could be that I push
it for you.
Please tell me your preference.

Regards,
Arnaud


On 06/06/2017 12:15 PM, Arnaud Pouliquen wrote:
> 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@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@metafoo.de>
>> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@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
>>