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@xxxxxxxxxx>
---
drivers/iio/Kconfig | 6 +++
drivers/iio/Makefile | 1 +
drivers/iio/buffer_cb.c | 113 +++++++++++++++++++++++++++++++++++++++++++
include/linux/iio/consumer.h | 46 ++++++++++++++++++
4 files changed, 166 insertions(+)
diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig
index fc937ac..f57f725 100644
--- a/drivers/iio/Kconfig
+++ b/drivers/iio/Kconfig
@@ -20,6 +20,12 @@ config IIO_BUFFER
if IIO_BUFFER
+config IIO_BUFFER_CB
+ boolean "IIO callback buffer used for push in kernel interfaces"
+ help
+ Should be selected by any drivers that do inkernel push
+ usage. That is, those where the data is pushed to the consumer.
+
config IIO_KFIFO_BUF
select IIO_TRIGGER
tristate "Industrial I/O buffering based on kfifo"
diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile
index 761f2b6..31d76a0 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-$(CONFIG_IIO_TRIGGER) += industrialio-trigger.o
+industrialio-$(CONFIG_IIO_BUFFER_CB) += buffer_cb.o
obj-$(CONFIG_IIO_TRIGGERED_BUFFER) += industrialio-triggered-buffer.o
obj-$(CONFIG_IIO_KFIFO_BUF) += kfifo_buf.o
diff --git a/drivers/iio/buffer_cb.c b/drivers/iio/buffer_cb.c
new file mode 100644
index 0000000..4d40e24
--- /dev/null
+++ b/drivers/iio/buffer_cb.c
@@ -0,0 +1,113 @@
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/consumer.h>
+
+struct iio_cb_buffer {
+ struct iio_buffer buffer;
+ int (*cb)(u8 *data, void *private);
+ void *private;
+ struct iio_channel *channels;
+};
+
+static int iio_buffer_cb_store_to(struct iio_buffer *buffer, u8 *data)
+{
+ struct iio_cb_buffer *cb_buff = container_of(buffer,
+ struct iio_cb_buffer,
+ buffer);
+
+ return cb_buff->cb(data, cb_buff->private);
+}
+
+static struct iio_buffer_access_funcs iio_cb_access = {
+ .store_to = &iio_buffer_cb_store_to,
+};
+
+struct iio_cb_buffer *iio_channel_get_all_cb(const char *name,
+ int (*cb)(u8 *data,
+ void *private),
+ void *private)
+{
+ int ret;
+ struct iio_cb_buffer *cb_buff;
+ struct iio_dev *indio_dev;
+ struct iio_channel *chan;
+
+ cb_buff = kzalloc(sizeof(*cb_buff), GFP_KERNEL);
+ if (cb_buff == NULL) {
+ ret = -ENOMEM;
+ goto error_ret;
+ }
+
+ cb_buff->private = private;
+ cb_buff->cb = cb;
+ cb_buff->buffer.access = &iio_cb_access;
+ INIT_LIST_HEAD(&cb_buff->buffer.demux_list);
+
+ cb_buff->channels = iio_channel_get_all(name);
+ if (IS_ERR(cb_buff->channels)) {
+ ret = PTR_ERR(cb_buff->channels);
+ goto error_free_cb_buff;
+ }
+
+ indio_dev = cb_buff->channels[0].indio_dev;
+ cb_buff->buffer.scan_mask
+ = kcalloc(BITS_TO_LONGS(indio_dev->masklength), sizeof(long),
+ GFP_KERNEL);
+ if (cb_buff->buffer.scan_mask == NULL) {
+ ret = -ENOMEM;
+ goto error_release_channels;
+ }
+ chan = &cb_buff->channels[0];
+ while (chan->indio_dev) {
+ if (chan->indio_dev != indio_dev) {
+ ret = -EINVAL;
+ goto error_release_channels;
+ }
+ set_bit(chan->channel->scan_index,
+ cb_buff->buffer.scan_mask);
+ chan++;
+ }
+
+ return cb_buff;
+
+error_release_channels:
+ iio_channel_release_all(cb_buff->channels);
+error_free_cb_buff:
+ kfree(cb_buff);
+error_ret:
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(iio_channel_get_all_cb);
+
+int iio_channel_start_all_cb(struct iio_cb_buffer *cb_buff)
+{
+ return iio_update_buffers(cb_buff->channels[0].indio_dev,
+ &cb_buff->buffer,
+ NULL);
+}
+EXPORT_SYMBOL_GPL(iio_channel_start_all_cb);
+
+void iio_channel_stop_all_cb(struct iio_cb_buffer *cb_buff)
+{
+ iio_update_buffers(cb_buff->channels[0].indio_dev,
+ NULL,
+ &cb_buff->buffer);
+}
+EXPORT_SYMBOL_GPL(iio_channel_stop_all_cb);
+
+void iio_channel_release_all_cb(struct iio_cb_buffer *cb_buff)
+{
+ iio_channel_release_all(cb_buff->channels);
+ kfree(cb_buff);
+}
+EXPORT_SYMBOL_GPL(iio_channel_release_all_cb);
+
+struct iio_channel
+*iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer)
+{
+ return cb_buffer->channels;
+}
+EXPORT_SYMBOL_GPL(iio_channel_cb_get_channels);
diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h
index 57efee6..caf103b 100644
--- a/include/linux/iio/consumer.h
+++ b/include/linux/iio/consumer.h
@@ -61,6 +61,52 @@ struct iio_channel *iio_channel_get_all(const char *name);
*/
void iio_channel_release_all(struct iio_channel *chan);
+struct iio_cb_buffer;
+/**
+ * iio_channel_get_all_cb() - register callback for triggered capture
+ * @name: Name of client device.
+ * @cb: Callback function.
+ * @private: Private data passed to callback.
+ *
+ * NB right now we have no ability to mux data from multiple devices.
+ * So if the channels requested come from different devices this will
+ * fail.
+ */
+struct iio_cb_buffer *iio_channel_get_all_cb(const char *name,
+ int (*cb)(u8 *data,
+ void *private),
+ void *private);
+/**
+ * iio_channel_release_all_cb() - release and unregister the callback.
+ * @cb_buffer: The callback buffer that was allocated.
+ */
+void iio_channel_release_all_cb(struct iio_cb_buffer *cb_buffer);
+
+/**
+ * iio_channel_start_all_cb() - start the flow of data through callback.
+ * @cb_buff: The callback buffer we are starting.
+ */
+int iio_channel_start_all_cb(struct iio_cb_buffer *cb_buff);
+
+/**
+ * iio_channel_stop_all_cb() - stop the flow of data through the callback.
+ * @cb_buff: The callback buffer we are stopping.
+ */
+void iio_channel_stop_all_cb(struct iio_cb_buffer *cb_buff);
+
+/**
+ * iio_channel_cb_get_channels() - get access to the underlying channels.
+ * @cb_buff: The callback buffers from whom we want the channel
+ * information.
+ *
+ * This function allows one to obtain information about the channels.
+ * Whilst this may allow direct reading if all buffers are disabled, the
+ * primary aim is to allow drivers that are consuming a channel to query
+ * things like scaling of the channel.
+ */
+struct iio_channel
+*iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer);
+
/**
* iio_read_channel_raw() - read from a given channel
* @chan: The channel being queried.
--
1.7.12.4
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