iio: buffer-callback: allow getting underlying iio_dev

Add iio_channel_cb_get_iio_dev function to allow getting the
underlying iio_dev. This is useful for setting the trigger of the
consumer ADC device.

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

2 files changed, 26 insertions, 10 deletions

diff --git a/drivers/iio/buffer/industrialio-buffer-cb.c b/drivers/iio/buffer/industrialio-buffer-cb.c
index 323079c3ccce..b8f550e47d3d 100644
--- a/drivers/iio/buffer/industrialio-buffer-cb.c
+++ b/drivers/iio/buffer/industrialio-buffer-cb.c
@@ -18,6 +18,7 @@ struct iio_cb_buffer {
         int (*cb)(const void *data, void *private);
         void *private;
         struct iio_channel *channels;
+        struct iio_dev *indio_dev;
 };
 
 static struct iio_cb_buffer *buffer_to_cb_buffer(struct iio_buffer *buffer)
@@ -52,7 +53,6 @@ struct iio_cb_buffer *iio_channel_get_all_cb(struct device *dev,
 {
         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);
@@ -72,17 +72,17 @@ struct iio_cb_buffer *iio_channel_get_all_cb(struct device *dev,
                 goto error_free_cb_buff;
         }
 
-        indio_dev = cb_buff->channels[0].indio_dev;
+        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);
+                = kcalloc(BITS_TO_LONGS(cb_buff->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) {
+                if (chan->indio_dev != cb_buff->indio_dev) {
                         ret = -EINVAL;
                         goto error_free_scan_mask;
                 }
@@ -105,17 +105,14 @@ 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,
+        return iio_update_buffers(cb_buff->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);
+        iio_update_buffers(cb_buff->indio_dev, NULL, &cb_buff->buffer);
 }
 EXPORT_SYMBOL_GPL(iio_channel_stop_all_cb);
 
@@ -133,6 +130,13 @@ struct iio_channel
 }
 EXPORT_SYMBOL_GPL(iio_channel_cb_get_channels);
 
+struct iio_dev
+*iio_channel_cb_get_iio_dev(const struct iio_cb_buffer *cb_buffer)
+{
+        return cb_buffer->indio_dev;
+}
+EXPORT_SYMBOL_GPL(iio_channel_cb_get_iio_dev);
+
 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
 MODULE_DESCRIPTION("Industrial I/O callback buffer");
 MODULE_LICENSE("GPL");
diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h
index 3d672f72e7ec..9edccfba1ffb 100644
--- a/include/linux/iio/consumer.h
+++ b/include/linux/iio/consumer.h
@@ -165,6 +165,18 @@ struct iio_channel
 *iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer);
 
 /**
+ * iio_channel_cb_get_iio_dev() - get access to the underlying device.
+ * @cb_buffer:          The callback buffer from whom we want the device
+ *                      information.
+ *
+ * This function allows one to obtain information about the device.
+ * The primary aim is to allow drivers that are consuming a device to query
+ * things like current trigger.
+ */
+struct iio_dev
+*iio_channel_cb_get_iio_dev(const struct iio_cb_buffer *cb_buffer);
+
+/**
  * iio_read_channel_raw() - read from a given channel
  * @chan:               The channel being queried.
  * @val:                Value read back.