1 files changed, 93 insertions, 15 deletions

diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
index 3a4f6a3ab80d..be82936c4089 100644
--- a/include/linux/iio/iio.h
+++ b/include/linux/iio/iio.h
@@ -130,14 +130,78 @@ struct iio_chan_spec_ext_info {
 };
 
 /**
+ * struct iio_enum - Enum channel info attribute
+ * @items:      An array of strings.
+ * @num_items:  Length of the item array.
+ * @set:        Set callback function, may be NULL.
+ * @get:        Get callback function, may be NULL.
+ *
+ * The iio_enum struct can be used to implement enum style channel attributes.
+ * Enum style attributes are those which have a set of strings which map to
+ * unsigned integer values. The IIO enum helper code takes care of mapping
+ * between value and string as well as generating a "_available" file which
+ * contains a list of all available items. The set callback will be called when
+ * the attribute is updated. The last parameter is the index to the newly
+ * activated item. The get callback will be used to query the currently active
+ * item and is supposed to return the index for it.
+ */
+struct iio_enum {
+        const char * const *items;
+        unsigned int num_items;
+        int (*set)(struct iio_dev *, const struct iio_chan_spec *, unsigned int);
+        int (*get)(struct iio_dev *, const struct iio_chan_spec *);
+};
+
+ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
+        uintptr_t priv, const struct iio_chan_spec *chan, char *buf);
+ssize_t iio_enum_read(struct iio_dev *indio_dev,
+        uintptr_t priv, const struct iio_chan_spec *chan, char *buf);
+ssize_t iio_enum_write(struct iio_dev *indio_dev,
+        uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
+        size_t len);
+
+/**
+ * IIO_ENUM() - Initialize enum extended channel attribute
+ * @_name:      Attribute name
+ * @_shared:    Whether the attribute is shared between all channels
+ * @_e:         Pointer to a iio_enum struct
+ *
+ * This should usually be used together with IIO_ENUM_AVAILABLE()
+ */
+#define IIO_ENUM(_name, _shared, _e) \
+{ \
+        .name = (_name), \
+        .shared = (_shared), \
+        .read = iio_enum_read, \
+        .write = iio_enum_write, \
+        .private = (uintptr_t)(_e), \
+}
+
+/**
+ * IIO_ENUM_AVAILABLE() - Initialize enum available extended channel attribute
+ * @_name:      Attribute name ("_available" will be appended to the name)
+ * @_e:         Pointer to a iio_enum struct
+ *
+ * Creates a read only attribute which list all the available enum items in a
+ * space separated list. This should usually be used together with IIO_ENUM()
+ */
+#define IIO_ENUM_AVAILABLE(_name, _e) \
+{ \
+        .name = (_name "_available"), \
+        .shared = true, \
+        .read = iio_enum_available_read, \
+        .private = (uintptr_t)(_e), \
+}
+
+/**
  * struct iio_chan_spec - specification of a single channel
  * @type:               What type of measurement is the channel making.
- * @channel:            What number or name do we wish to assign the channel.
+ * @channel:            What number do we wish to assign the channel.
  * @channel2:           If there is a second number for a differential
  *                      channel then this is it. If modified is set then the
  *                      value here specifies the modifier.
  * @address:            Driver specific identifier.
- * @scan_index: Monotonic index to give ordering in scans when read
+ * @scan_index:         Monotonic index to give ordering in scans when read
  *                      from a buffer.
  * @scan_type:          Sign:           's' or 'u' to specify signed or unsigned
  *                      realbits:       Number of valid bits of data
@@ -147,14 +211,14 @@ struct iio_chan_spec_ext_info {
  *                      endianness:     little or big endian
  * @info_mask:          What information is to be exported about this channel.
  *                      This includes calibbias, scale etc.
- * @event_mask: What events can this channel produce.
+ * @event_mask:         What events can this channel produce.
  * @ext_info:           Array of extended info attributes for this channel.
  *                      The array is NULL terminated, the last element should
- *                      have it's name field set to NULL.
+ *                      have its name field set to NULL.
  * @extend_name:        Allows labeling of channel attributes with an
  *                      informative name. Note this has no effect codes etc,
  *                      unlike modifiers.
- * @datasheet_name:     A name used in in kernel mapping of channels. It should
+ * @datasheet_name:     A name used in in-kernel mapping of channels. It should
  *                      correspond to the first name that the channel is referred
  *                      to by in the datasheet (e.g. IND), or the nearest
  *                      possible compound name (e.g. IND-INC).
@@ -163,9 +227,8 @@ struct iio_chan_spec_ext_info {
  *                      channel2. Examples are IIO_MOD_X for axial sensors about
  *                      the 'x' axis.
  * @indexed:            Specify the channel has a numerical index. If not,
- *                      the value in channel will be suppressed for attribute
- *                      but not for event codes. Typically set it to 0 when
- *                      the index is false.
+ *                      the channel index number will be suppressed for sysfs
+ *                      attributes but not for event codes.
  * @differential:       Channel is differential.
  */
 struct iio_chan_spec {
@@ -300,12 +363,16 @@ struct iio_info {
  * @predisable:         [DRIVER] function to run prior to marking buffer
  *                      disabled
  * @postdisable:        [DRIVER] function to run after marking buffer disabled
+ * @validate_scan_mask: [DRIVER] function callback to check whether a given
+ *                      scan mask is valid for the device.
  */
 struct iio_buffer_setup_ops {
         int                             (*preenable)(struct iio_dev *);
         int                             (*postenable)(struct iio_dev *);
         int                             (*predisable)(struct iio_dev *);
         int                             (*postdisable)(struct iio_dev *);
+        bool (*validate_scan_mask)(struct iio_dev *indio_dev,
+                                   const unsigned long *scan_mask);
 };
 
 /**
@@ -329,7 +396,7 @@ struct iio_buffer_setup_ops {
  * @trig:               [INTERN] current device trigger (buffer modes)
  * @pollfunc:           [DRIVER] function run on trigger being received
  * @channels:           [DRIVER] channel specification structure table
- * @num_channels:       [DRIVER] number of chanels specified in @channels.
+ * @num_channels:       [DRIVER] number of channels specified in @channels.
  * @channel_attr_list:  [INTERN] keep track of automatically created channel
  *                      attributes
  * @chan_attr_group:    [INTERN] group for all attrs in base directory
@@ -419,7 +486,7 @@ extern struct bus_type iio_bus_type;
 
 /**
  * iio_device_put() - reference counted deallocation of struct device
- * @dev: the iio_device containing the device
+ * @indio_dev:          IIO device structure containing the device
  **/
 static inline void iio_device_put(struct iio_dev *indio_dev)
 {
@@ -429,7 +496,7 @@ static inline void iio_device_put(struct iio_dev *indio_dev)
 
 /**
  * dev_to_iio_dev() - Get IIO device struct from a device struct
- * @dev: The device embedded in the IIO device
+ * @dev:                The device embedded in the IIO device
  *
  * Note: The device must be a IIO device, otherwise the result is undefined.
  */
@@ -438,11 +505,22 @@ static inline struct iio_dev *dev_to_iio_dev(struct device *dev)
         return container_of(dev, struct iio_dev, dev);
 }
 
+/**
+ * iio_device_get() - increment reference count for the device
+ * @indio_dev:          IIO device structure
+ *
+ * Returns: The passed IIO device
+ **/
+static inline struct iio_dev *iio_device_get(struct iio_dev *indio_dev)
+{
+        return indio_dev ? dev_to_iio_dev(get_device(&indio_dev->dev)) : NULL;
+}
+
 /* Can we make this smaller? */
 #define IIO_ALIGN L1_CACHE_BYTES
 /**
  * iio_device_alloc() - allocate an iio_dev from a driver
- * @sizeof_priv: Space to allocate for private structure.
+ * @sizeof_priv:        Space to allocate for private structure.
  **/
 struct iio_dev *iio_device_alloc(int sizeof_priv);
 
@@ -459,13 +537,13 @@ static inline struct iio_dev *iio_priv_to_dev(void *priv)
 
 /**
  * iio_device_free() - free an iio_dev from a driver
- * @dev: the iio_dev associated with the device
+ * @indio_dev:          the iio_dev associated with the device
  **/
 void iio_device_free(struct iio_dev *indio_dev);
 
 /**
  * iio_buffer_enabled() - helper function to test if the buffer is enabled
- * @indio_dev:          IIO device info structure for device
+ * @indio_dev:          IIO device structure for device
  **/
 static inline bool iio_buffer_enabled(struct iio_dev *indio_dev)
 {
@@ -475,7 +553,7 @@ static inline bool iio_buffer_enabled(struct iio_dev *indio_dev)
 
 /**
  * iio_get_debugfs_dentry() - helper function to get the debugfs_dentry
- * @indio_dev:          IIO device info structure for device
+ * @indio_dev:          IIO device structure for device
  **/
 #if defined(CONFIG_DEBUG_FS)
 static inline struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev)