staging:iio: add a callback buffer for in kernel push interface
This callback buffer is meant to be opaque to users, but basically adds a very simple pass through buffer to which data may be pushed when it is inserted into the buffer list. Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
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0464415dd2
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92d1079b28
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@ -20,6 +20,12 @@ config IIO_BUFFER
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if IIO_BUFFER
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if IIO_BUFFER
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config IIO_BUFFER_CB
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boolean "IIO callback buffer used for push in-kernel interfaces"
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help
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Should be selected by any drivers that do-inkernel push
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usage. That is, those where the data is pushed to the consumer.
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config IIO_KFIFO_BUF
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config IIO_KFIFO_BUF
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select IIO_TRIGGER
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select IIO_TRIGGER
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tristate "Industrial I/O buffering based on kfifo"
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tristate "Industrial I/O buffering based on kfifo"
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@ -6,6 +6,7 @@ obj-$(CONFIG_IIO) += industrialio.o
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industrialio-y := industrialio-core.o industrialio-event.o inkern.o
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industrialio-y := industrialio-core.o industrialio-event.o inkern.o
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industrialio-$(CONFIG_IIO_BUFFER) += industrialio-buffer.o
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industrialio-$(CONFIG_IIO_BUFFER) += industrialio-buffer.o
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industrialio-$(CONFIG_IIO_TRIGGER) += industrialio-trigger.o
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industrialio-$(CONFIG_IIO_TRIGGER) += industrialio-trigger.o
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industrialio-$(CONFIG_IIO_BUFFER_CB) += buffer_cb.o
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obj-$(CONFIG_IIO_TRIGGERED_BUFFER) += industrialio-triggered-buffer.o
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obj-$(CONFIG_IIO_TRIGGERED_BUFFER) += industrialio-triggered-buffer.o
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obj-$(CONFIG_IIO_KFIFO_BUF) += kfifo_buf.o
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obj-$(CONFIG_IIO_KFIFO_BUF) += kfifo_buf.o
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@ -0,0 +1,113 @@
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/err.h>
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#include <linux/export.h>
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#include <linux/iio/buffer.h>
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#include <linux/iio/consumer.h>
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struct iio_cb_buffer {
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struct iio_buffer buffer;
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int (*cb)(u8 *data, void *private);
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void *private;
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struct iio_channel *channels;
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};
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static int iio_buffer_cb_store_to(struct iio_buffer *buffer, u8 *data)
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{
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struct iio_cb_buffer *cb_buff = container_of(buffer,
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struct iio_cb_buffer,
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buffer);
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return cb_buff->cb(data, cb_buff->private);
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}
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static struct iio_buffer_access_funcs iio_cb_access = {
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.store_to = &iio_buffer_cb_store_to,
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};
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struct iio_cb_buffer *iio_channel_get_all_cb(const char *name,
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int (*cb)(u8 *data,
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void *private),
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void *private)
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{
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int ret;
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struct iio_cb_buffer *cb_buff;
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struct iio_dev *indio_dev;
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struct iio_channel *chan;
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cb_buff = kzalloc(sizeof(*cb_buff), GFP_KERNEL);
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if (cb_buff == NULL) {
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ret = -ENOMEM;
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goto error_ret;
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}
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cb_buff->private = private;
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cb_buff->cb = cb;
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cb_buff->buffer.access = &iio_cb_access;
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INIT_LIST_HEAD(&cb_buff->buffer.demux_list);
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cb_buff->channels = iio_channel_get_all(name);
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if (IS_ERR(cb_buff->channels)) {
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ret = PTR_ERR(cb_buff->channels);
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goto error_free_cb_buff;
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}
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indio_dev = cb_buff->channels[0].indio_dev;
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cb_buff->buffer.scan_mask
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= kcalloc(BITS_TO_LONGS(indio_dev->masklength), sizeof(long),
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GFP_KERNEL);
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if (cb_buff->buffer.scan_mask == NULL) {
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ret = -ENOMEM;
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goto error_release_channels;
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}
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chan = &cb_buff->channels[0];
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while (chan->indio_dev) {
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if (chan->indio_dev != indio_dev) {
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ret = -EINVAL;
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goto error_release_channels;
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}
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set_bit(chan->channel->scan_index,
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cb_buff->buffer.scan_mask);
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chan++;
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}
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return cb_buff;
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error_release_channels:
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iio_channel_release_all(cb_buff->channels);
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error_free_cb_buff:
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kfree(cb_buff);
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error_ret:
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return ERR_PTR(ret);
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}
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EXPORT_SYMBOL_GPL(iio_channel_get_all_cb);
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int iio_channel_start_all_cb(struct iio_cb_buffer *cb_buff)
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{
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return iio_update_buffers(cb_buff->channels[0].indio_dev,
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&cb_buff->buffer,
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NULL);
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}
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EXPORT_SYMBOL_GPL(iio_channel_start_all_cb);
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void iio_channel_stop_all_cb(struct iio_cb_buffer *cb_buff)
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{
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iio_update_buffers(cb_buff->channels[0].indio_dev,
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NULL,
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&cb_buff->buffer);
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}
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EXPORT_SYMBOL_GPL(iio_channel_stop_all_cb);
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void iio_channel_release_all_cb(struct iio_cb_buffer *cb_buff)
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{
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iio_channel_release_all(cb_buff->channels);
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kfree(cb_buff);
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}
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EXPORT_SYMBOL_GPL(iio_channel_release_all_cb);
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struct iio_channel
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*iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer)
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{
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return cb_buffer->channels;
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}
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EXPORT_SYMBOL_GPL(iio_channel_cb_get_channels);
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@ -61,6 +61,52 @@ struct iio_channel *iio_channel_get_all(const char *name);
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*/
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*/
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void iio_channel_release_all(struct iio_channel *chan);
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void iio_channel_release_all(struct iio_channel *chan);
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struct iio_cb_buffer;
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/**
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* iio_channel_get_all_cb() - register callback for triggered capture
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* @name: Name of client device.
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* @cb: Callback function.
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* @private: Private data passed to callback.
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*
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* NB right now we have no ability to mux data from multiple devices.
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* So if the channels requested come from different devices this will
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* fail.
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*/
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struct iio_cb_buffer *iio_channel_get_all_cb(const char *name,
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int (*cb)(u8 *data,
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void *private),
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void *private);
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/**
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* iio_channel_release_all_cb() - release and unregister the callback.
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* @cb_buffer: The callback buffer that was allocated.
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*/
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void iio_channel_release_all_cb(struct iio_cb_buffer *cb_buffer);
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/**
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* iio_channel_start_all_cb() - start the flow of data through callback.
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* @cb_buff: The callback buffer we are starting.
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*/
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int iio_channel_start_all_cb(struct iio_cb_buffer *cb_buff);
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/**
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* iio_channel_stop_all_cb() - stop the flow of data through the callback.
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* @cb_buff: The callback buffer we are stopping.
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*/
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void iio_channel_stop_all_cb(struct iio_cb_buffer *cb_buff);
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/**
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* iio_channel_cb_get_channels() - get access to the underlying channels.
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* @cb_buff: The callback buffer from whom we want the channel
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* information.
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*
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* This function allows one to obtain information about the channels.
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* Whilst this may allow direct reading if all buffers are disabled, the
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* primary aim is to allow drivers that are consuming a channel to query
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* things like scaling of the channel.
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*/
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struct iio_channel
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*iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer);
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/**
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/**
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* iio_read_channel_raw() - read from a given channel
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* iio_read_channel_raw() - read from a given channel
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* @chan: The channel being queried.
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* @chan: The channel being queried.
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