From: Lars-Peter Clausen lars@metafoo.de
Hardware consumer interface 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 Reviewed-by: Jonathan Cameron Jonathan.Cameron@huawei.com --- V6 to V7 update: - SPDX-Licensing
drivers/iio/buffer/Kconfig | 10 ++ drivers/iio/buffer/Makefile | 1 + drivers/iio/buffer/industrialio-hw-consumer.c | 181 ++++++++++++++++++++++++++ include/linux/iio/hw-consumer.h | 19 +++ 4 files changed, 211 insertions(+) create mode 100644 drivers/iio/buffer/industrialio-hw-consumer.c create mode 100644 include/linux/iio/hw-consumer.h
diff --git a/drivers/iio/buffer/Kconfig b/drivers/iio/buffer/Kconfig index 4ffd3db..338774c 100644 --- a/drivers/iio/buffer/Kconfig +++ b/drivers/iio/buffer/Kconfig @@ -29,6 +29,16 @@ config IIO_BUFFER_DMAENGINE
Should be selected by drivers that want to use this functionality.
+config IIO_BUFFER_HW_CONSUMER + tristate "Industrial I/O HW buffering" + help + Provides a way to bonding when an IIO device has a direct connection + to another device in hardware. In this case buffers for data transfers + are handled by hardware. + + Should be selected by drivers that want to use the generic Hw consumer + interface. + config IIO_KFIFO_BUF tristate "Industrial I/O buffering based on kfifo" help diff --git a/drivers/iio/buffer/Makefile b/drivers/iio/buffer/Makefile index 85beaae..324a36b 100644 --- a/drivers/iio/buffer/Makefile +++ b/drivers/iio/buffer/Makefile @@ -6,5 +6,6 @@ obj-$(CONFIG_IIO_BUFFER_CB) += industrialio-buffer-cb.o obj-$(CONFIG_IIO_BUFFER_DMA) += industrialio-buffer-dma.o obj-$(CONFIG_IIO_BUFFER_DMAENGINE) += industrialio-buffer-dmaengine.o +obj-$(CONFIG_IIO_BUFFER_HW_CONSUMER) += industrialio-hw-consumer.o obj-$(CONFIG_IIO_TRIGGERED_BUFFER) += industrialio-triggered-buffer.o obj-$(CONFIG_IIO_KFIFO_BUF) += kfifo_buf.o diff --git a/drivers/iio/buffer/industrialio-hw-consumer.c b/drivers/iio/buffer/industrialio-hw-consumer.c new file mode 100644 index 0000000..993ecdc --- /dev/null +++ b/drivers/iio/buffer/industrialio-hw-consumer.c @@ -0,0 +1,181 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2017 Analog Devices Inc. + * Author: Lars-Peter Clausen lars@metafoo.de + */ + +#include <linux/err.h> +#include <linux/export.h> +#include <linux/slab.h> +#include <linux/module.h> + +#include <linux/iio/iio.h> +#include <linux/iio/consumer.h> +#include <linux/iio/hw-consumer.h> +#include <linux/iio/buffer_impl.h> + +/** + * struct iio_hw_consumer - IIO hw consumer block + * @buffers: hardware buffers list head. + * @channels: IIO provider channels. + */ +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; + long scan_mask[]; +}; + +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); +} + +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) +{ + size_t mask_size = BITS_TO_LONGS(indio_dev->masklength) * sizeof(long); + 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) + mask_size, GFP_KERNEL); + if (!buf) + return NULL; + + buf->buffer.access = &iio_hw_buf_access; + buf->indio_dev = indio_dev; + buf->buffer.scan_mask = buf->scan_mask; + + iio_buffer_init(&buf->buffer); + list_add_tail(&buf->head, &hwc->buffers); + + return buf; +} + +/** + * iio_hw_consumer_alloc() - Allocate IIO hardware consumer + * @dev: Pointer to consumer device. + * + * Returns a valid iio_hw_consumer on success or a ERR_PTR() on failure. + */ +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) { + 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); + +/** + * iio_hw_consumer_free() - Free IIO hardware consumer + * @hwc: hw consumer to free. + */ +void iio_hw_consumer_free(struct iio_hw_consumer *hwc) +{ + struct hw_consumer_buffer *buf, *n; + + iio_channel_release_all(hwc->channels); + list_for_each_entry_safe(buf, n, &hwc->buffers, head) + iio_buffer_put(&buf->buffer); + kfree(hwc); +} +EXPORT_SYMBOL_GPL(iio_hw_consumer_free); + +/** + * iio_hw_consumer_enable() - Enable IIO hardware consumer + * @hwc: iio_hw_consumer to enable. + * + * Returns 0 on success. + */ +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); + +/** + * iio_hw_consumer_disable() - Disable IIO hardware consumer + * @hwc: iio_hw_consumer to disable. + */ +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); + +MODULE_AUTHOR("Lars-Peter Clausen lars@metafoo.de"); +MODULE_DESCRIPTION("Hardware consumer buffer the IIO framework"); +MODULE_LICENSE("GPL v2"); diff --git a/include/linux/iio/hw-consumer.h b/include/linux/iio/hw-consumer.h new file mode 100644 index 0000000..db8c00b --- /dev/null +++ b/include/linux/iio/hw-consumer.h @@ -0,0 +1,19 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Industrial I/O in kernel hardware consumer interface + * + * Copyright 2017 Analog Devices Inc. + * Author: Lars-Peter Clausen lars@metafoo.de + */ + +#ifndef LINUX_IIO_HW_CONSUMER_H +#define LINUX_IIO_HW_CONSUMER_H + +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