1 files changed, 56 insertions, 5 deletions

diff --git a/include/linux/iio/buffer.h b/include/linux/iio/buffer.h
index 2bac0eb8948d..15607b45221a 100644
--- a/include/linux/iio/buffer.h
+++ b/include/linux/iio/buffer.h
@@ -11,6 +11,7 @@
 #define _IIO_BUFFER_GENERIC_H_
 #include <linux/sysfs.h>
 #include <linux/iio/iio.h>
+#include <linux/kref.h>
 
 #ifdef CONFIG_IIO_BUFFER
 
@@ -26,6 +27,8 @@ struct iio_buffer;
  * @set_bytes_per_datum:set number of bytes per datum
  * @get_length:         get number of datums in buffer
  * @set_length:         set number of datums in buffer
+ * @release:            called when the last reference to the buffer is dropped,
+ *                      should free all resources allocated by the buffer.
  *
  * The purpose of this structure is to make the buffer element
  * modular as event for a given driver, different usecases may require
@@ -36,7 +39,7 @@ struct iio_buffer;
  * any of them not existing.
  **/
 struct iio_buffer_access_funcs {
-        int (*store_to)(struct iio_buffer *buffer, u8 *data);
+        int (*store_to)(struct iio_buffer *buffer, const void *data);
         int (*read_first_n)(struct iio_buffer *buffer,
                             size_t n,
                             char __user *buf);
@@ -47,6 +50,8 @@ struct iio_buffer_access_funcs {
         int (*set_bytes_per_datum)(struct iio_buffer *buffer, size_t bpd);
         int (*get_length)(struct iio_buffer *buffer);
         int (*set_length)(struct iio_buffer *buffer, int length);
+
+        void (*release)(struct iio_buffer *buffer);
 };
 
 /**
@@ -67,6 +72,7 @@ struct iio_buffer_access_funcs {
  * @demux_list:         [INTERN] list of operations required to demux the scan.
  * @demux_bounce:       [INTERN] buffer for doing gather from incoming scan.
  * @buffer_list:        [INTERN] entry in the devices list of current buffers.
+ * @ref:                [INTERN] reference count of the buffer.
  */
 struct iio_buffer {
         int                                     length;
@@ -81,8 +87,9 @@ struct iio_buffer {
         bool                                    stufftoread;
         const struct attribute_group *attrs;
         struct list_head                        demux_list;
-        unsigned char                           *demux_bounce;
+        void                                    *demux_bounce;
         struct list_head                        buffer_list;
+        struct kref                             ref;
 };
 
 /**
@@ -120,7 +127,32 @@ int iio_scan_mask_set(struct iio_dev *indio_dev,
  * @indio_dev:          iio_dev structure for device.
  * @data:               Full scan.
  */
-int iio_push_to_buffers(struct iio_dev *indio_dev, unsigned char *data);
+int iio_push_to_buffers(struct iio_dev *indio_dev, const void *data);
+
+/*
+ * iio_push_to_buffers_with_timestamp() - push data and timestamp to buffers
+ * @indio_dev:          iio_dev structure for device.
+ * @data:               sample data
+ * @timestamp:          timestamp for the sample data
+ *
+ * Pushes data to the IIO device's buffers. If timestamps are enabled for the
+ * device the function will store the supplied timestamp as the last element in
+ * the sample data buffer before pushing it to the device buffers. The sample
+ * data buffer needs to be large enough to hold the additional timestamp
+ * (usually the buffer should be indio->scan_bytes bytes large).
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ */
+static inline int iio_push_to_buffers_with_timestamp(struct iio_dev *indio_dev,
+        void *data, int64_t timestamp)
+{
+        if (indio_dev->scan_timestamp) {
+                size_t ts_offset = indio_dev->scan_bytes / sizeof(int64_t) - 1;
+                ((int64_t *)data)[ts_offset] = timestamp;
+        }
+
+        return iio_push_to_buffers(indio_dev, data);
+}
 
 int iio_update_demux(struct iio_dev *indio_dev);
 
@@ -174,11 +206,27 @@ ssize_t iio_buffer_show_enable(struct device *dev,
                                            iio_buffer_show_enable,      \
                                            iio_buffer_store_enable)
 
-int iio_sw_buffer_preenable(struct iio_dev *indio_dev);
-
 bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev,
         const unsigned long *mask);
 
+struct iio_buffer *iio_buffer_get(struct iio_buffer *buffer);
+void iio_buffer_put(struct iio_buffer *buffer);
+
+/**
+ * iio_device_attach_buffer - Attach a buffer to a IIO device
+ * @indio_dev: The device the buffer should be attached to
+ * @buffer: The buffer to attach to the device
+ *
+ * This function attaches a buffer to a IIO device. The buffer stays attached to
+ * the device until the device is freed. The function should only be called at
+ * most once per device.
+ */
+static inline void iio_device_attach_buffer(struct iio_dev *indio_dev,
+        struct iio_buffer *buffer)
+{
+        indio_dev->buffer = iio_buffer_get(buffer);
+}
+
 #else /* CONFIG_IIO_BUFFER */
 
 static inline int iio_buffer_register(struct iio_dev *indio_dev,
@@ -191,6 +239,9 @@ static inline int iio_buffer_register(struct iio_dev *indio_dev,
 static inline void iio_buffer_unregister(struct iio_dev *indio_dev)
 {}
 
+static inline void iio_buffer_get(struct iio_buffer *buffer) {}
+static inline void iio_buffer_put(struct iio_buffer *buffer) {}
+
 #endif /* CONFIG_IIO_BUFFER */
 
 #endif /* _IIO_BUFFER_GENERIC_H_ */