zio: remove cset operation init() and exit()

At the moment, no known driver use these operations so we can "safely"
remove them from the framework.
We decide to remove init() and exit() because, in the current
implementation, they introduce more problems than they solve.

If you used these functions, we suggest you to move your init()
functions in the probe() function and your exit() functions before
deregister the device.

Signed-off-by: Federico Vaga <federico.vaga@gmail.com>
Acked-by: Alessandro Rubini <rubini@gnudd.com>

bus.c

@@ -163,6 +163,7 @@ static int zio_drv_probe(struct device *dev)
 	if (zdrv->probe)
 		return zdrv->probe(zdev);
 	pr_debug("%s:%d\n", __func__, __LINE__);
+
 	return 0;
 }
 

doc/zio-manual.in

@@ -128,7 +128,7 @@ The ZIO code base is designed around three main items:
         See @ref{The Trigger}.
 
 @cindex buffer
-@item Buffer 
+@item Buffer
 	A buffer stores blocks, either input blocks
         generated by a trigger or output blocks generated by some
         injecting code. One end of the buffer is always connected to a
@@ -306,7 +306,7 @@ ZIO framework at some time in the future. Some of them are already
 in @i{beta} stage, available from @i{git} branches in our @t{ohwr} repository.
 
 @itemize @bullet
- 
+
 @cindex input subsystem and ZIO
 @item Supporting an @code{input_device} buffer type
 
@@ -766,7 +766,7 @@ storage of blocks. This is the actual definition:
            void                    *data;
            size_t                  datalen;
            size_t                  uoff;
-   }; 
+   };
 @end example
 
 The meaning of the fields is as follows:
@@ -775,7 +775,7 @@ The meaning of the fields is as follows:
 @item ctrl_flags
 
 	The field includes a pointer to the control structure and one flag
-        bit, described below. 
+        bit, described below.
 
 @item data
 
@@ -865,7 +865,7 @@ the Linux kernel.
 @cindex meta-information
 The control is designed to offer the full meta-information needed to
 describe a block. In includes the unique global identification
-of the channel, as well as the name and parameters for the 
+of the channel, as well as the name and parameters for the
 current trigger. Applications can thus pass around a
 block without knowing what it is; knowledge about device and
 trigger details can be concentrated in a single place, without the
@@ -959,7 +959,7 @@ the fields are not yet being filled by the core.
         pipeline, and are persistent until cleared by means of a
         @i{sysfs} attribute.  ZIO alarms are defined
         by the core, and we currently support ``lost block'' and ``lost
-        trigger''. 
+        trigger''.
 
 @cindex sequence numbers in control structures
 @item seq_num
@@ -1171,7 +1171,7 @@ The fields have the following meaning:
 	The @code{dev_id} field is used differently by different drivers:
         software-only drivers like @t{zio-zero} and @t{zio-mini} just count
         starting from zero, while PCI cards use the @i{bus} and @i{defvn}
-        identifiers as geographical numbering. 
+        identifiers as geographical numbering.
 
 	For input, all fields are set by ZIO; for output they are ignored
         if data reaches ZIO through char devices. The network interface
@@ -1359,7 +1359,7 @@ extensions using the suggested ZIO protocol. Such protocol already
 works with the unextended control.
 @c and actually it is already used
 @c by the example programs in the @i{tools} subdirectory.
-Clearly, 
+Clearly,
 generic code that ignores metadata and only manages data, is not affected.
 
 For the input direction, generic code that reads a ZIO control device
@@ -1502,7 +1502,7 @@ food items. The envelope describes the specific content (including the
 timestamp, name, item size and item count of each package), and you can choose
 to read the envelope or not; similarly, you can choose to eat the food
 or not, and sometimes you make the choice only after reading the
-envelope.  
+envelope.
 
 @tindex mem_offset
 @cindex mmap for data access
@@ -1519,7 +1519,7 @@ This is represented in @ref{fig:mmap}.
 @sp 1
 
 @cindex vmalloc buffer type
-An attribute of the @i{vmalloc} buffer, called @t{merge-data} 
+An attribute of the @i{vmalloc} buffer, called @t{merge-data}
 can turn it into a
 real circular buffer: a buffer instance, if so configured, can merge
 (stick together)
@@ -1702,34 +1702,34 @@ preferred name for pointers to that data structure, used in the code.
 @headitem Struct name or C type @tab Name  @tab Var name  @tab Description
 
 @item zio_device
-@tab full device 
-@tab zdev 
+@tab full device
+@tab zdev
 @tab The overall I/O device, either a board or a  chip.
 
 @item zio_cset
 @tab cset
 @tab cset
-@tab Part of a device; a group of channels with the same physical features. 
+@tab Part of a device; a group of channels with the same physical features.
 
 @item zio_channel
 @tab channel
 @tab chan
-@tab Part of a cset; it is the single data stream endpoint, input or output. 
+@tab Part of a cset; it is the single data stream endpoint, input or output.
 
 @item zio_device_operations
 @tab device operations
 @tab d_op
-@tab Device-specific methods that act on attributes and data blocks. 
+@tab Device-specific methods that act on attributes and data blocks.
 
 @item zio_buffer_type
 @tab buffer type
 @tab zbuf
-@tab Description of a buffer. 
+@tab Description of a buffer.
 
 @item zio_bi
 @tab buffer instance
 @tab bi
-@tab Instance of a buffer type associated to a specific channel. 
+@tab Instance of a buffer type associated to a specific channel.
 
 @item zio_buffer_operations
 @tab buffer operations
@@ -1965,17 +1965,6 @@ or used by the developer are:
 
 	A private pointer for the device, in case it needs it.
 
-@cindex cset, init and exit functions
-@cindex init function for the cset
-@cindex exit function for the cset
-@item int (*init)(struct zio_cset *cset)
-@itemx void (*exit)(struct zio_cset *cset)
-
-	The function pointers, if not NULL, are called by ZIO at
-        cset registration and removal time, after allocating and before
-        removing, resp., the channel array. They may useful to channel
-        sets that need to setup and release the @code{priv_d} field.
-
 @end table
 
 @c --------------------------------------------------------------------------
@@ -1999,9 +1988,7 @@ are:
 @cindex private pointers in the channel
 @item void *priv_d
 
-	A private pointer for the device (may be allocated by the
-        @code{init} function of the cset and released by the corresponding
-        @code{exit} function).
+	A private pointer for the device.
 
 @item void *priv_t
 
@@ -2032,7 +2019,7 @@ struct zio_driver {
 The client module, thus, must specify a table of device types it is
 able to drive. When a match is found, the ZIO core calls the method
 @i{probe}, which can return success (zero) or failure (a negative error
-code).  Similarly, the core calls @i{remove} when the device disappears 
+code).  Similarly, the core calls @i{remove} when the device disappears
 or the driver is unloaded. Both methods are optional (if missing,
 success is assumed).
 
@@ -2325,7 +2312,7 @@ The detailed meaning of the operations is as follows:
 	Abort, if defined, is called when an already-armed trigger event
         must be aborted. This happens, for example, because event
         parameters changed (e.g., the block size).  The method must
-        call @t{cset->stop_io} if not NULL and 
+        call @t{cset->stop_io} if not NULL and
         dispose the @i{active_block} for each channel, setting the
         pointer to NULL. Please check how it is used in @t{helpers.c}.
         The method
@@ -2532,7 +2519,7 @@ This release of ZIO includes the following trigger types:
         slack to be used in programming the kernel resource.
 
 @cindex irq trigger
-@cindex gpio as a trigger source        
+@cindex gpio as a trigger source
 @item irq
 
 	External-interrupt. The module receives a @t{irq=} parameter,
@@ -2543,7 +2530,7 @@ This release of ZIO includes the following trigger types:
         for demonstration purposes.
 
 @end table
-        
+
 
 @c ==========================================================================
 @node Available Buffers

include/linux/zio.h

@@ -188,9 +188,6 @@ struct zio_cset {
 	struct zio_channel	*chan;
 	unsigned int		n_chan;
 
-	int			(*init)(struct zio_cset *cset);
-	void			(*exit)(struct zio_cset *cset);
-
 	void			*priv_d;	/* private for the device */
 
 	struct list_head	list_cset;	/* for cset global list */

objects.c

@@ -768,12 +768,7 @@ static int cset_register(struct zio_cset *cset, struct zio_cset *cset_t)
 		if (err)
 			goto out_reg;
 	}
-	/* Private initialization function */
-	if (cset->init) {
-		err = cset->init(cset);
-		if (err)
-			goto out_reg;
-	}
+
 	spin_lock(&zstat->lock);
 	list_add(&cset->list_cset, &zstat->list_cset);
 	spin_unlock(&zstat->lock);
@@ -825,9 +820,6 @@ static void cset_unregister(struct zio_cset *cset)
 	spin_unlock(&zstat->lock);
 	/* Make it idle */
 	zio_trigger_abort_disable(cset, 1);
-	/* Private exit function */
-	if (cset->exit)
-		cset->exit(cset);
 	/* Unregister all child channels */
 	for (i = 0; i < cset->n_chan; i++)
 		chan_unregister(&cset->chan[i]);