staging: comedi: pass subdevice to comedi_buf_write_free()

Change the parameters of `comedi_buf_write_free()` to pass a pointer to
the comedi subdevice instead of a pointer to the "async" structure
belonging to the subdevice.

The main aim at the moment is to replace all the `struct comedi_async *`
parameters with `struct comedi_subdevice *` parameters in the comedi
driver API.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/comedi_buf.c

@@ -329,9 +329,10 @@ unsigned int comedi_buf_write_n_allocated(struct comedi_async *async)
 }
 
 /* transfers a chunk from writer to filled buffer space */
-unsigned int comedi_buf_write_free(struct comedi_async *async,
+unsigned int comedi_buf_write_free(struct comedi_subdevice *s,
 				   unsigned int nbytes)
 {
+	struct comedi_async *async = s->async;
 	unsigned int allocated = comedi_buf_write_n_allocated(async);
 
 	if (nbytes > allocated)
@@ -426,7 +427,7 @@ int comedi_buf_put(struct comedi_subdevice *s, unsigned short x)
 		return 0;
 	}
 	*(unsigned short *)(async->prealloc_buf + async->buf_write_ptr) = x;
-	comedi_buf_write_free(async, sizeof(short));
+	comedi_buf_write_free(s, sizeof(short));
 	return 1;
 }
 EXPORT_SYMBOL_GPL(comedi_buf_put);

drivers/staging/comedi/comedi_fops.c

@@ -1005,7 +1005,7 @@ static int do_bufinfo_ioctl(struct comedi_device *dev,
 	if (bi.bytes_written && (s->subdev_flags & SDF_CMD_WRITE)) {
 		bi.bytes_written =
 		    comedi_buf_write_alloc(s, bi.bytes_written);
-		comedi_buf_write_free(async, bi.bytes_written);
+		comedi_buf_write_free(s, bi.bytes_written);
 	}
 
 copyback_position:
@@ -2167,7 +2167,7 @@ static ssize_t comedi_write(struct file *file, const char __user *buf,
 			n -= m;
 			retval = -EFAULT;
 		}
-		comedi_buf_write_free(async, n);
+		comedi_buf_write_free(s, n);
 
 		count += n;
 		nbytes -= n;

drivers/staging/comedi/comedidev.h

@@ -337,7 +337,7 @@ static inline unsigned int bytes_per_sample(const struct comedi_subdevice *subd)
 int comedi_set_hw_dev(struct comedi_device *dev, struct device *hw_dev);
 
 unsigned int comedi_buf_write_alloc(struct comedi_subdevice *s, unsigned int n);
-unsigned int comedi_buf_write_free(struct comedi_async *, unsigned int);
+unsigned int comedi_buf_write_free(struct comedi_subdevice *s, unsigned int n);
 
 unsigned int comedi_buf_read_n_available(struct comedi_async *);
 unsigned int comedi_buf_read_alloc(struct comedi_async *, unsigned int);

drivers/staging/comedi/drivers/addi-data/hwdrv_apci3200.c

@@ -2716,7 +2716,7 @@ static int i_APCI3200_InterruptHandleEos(struct comedi_device *dev)
 				ui_ScanValueArray, (7 + 12) * sizeof(unsigned int));
 
 			/*  Update comedi buffer pinters indexes */
-			comedi_buf_write_free(s->async,
+			comedi_buf_write_free(s,
 				(7 + 12) * sizeof(unsigned int));
 
 			/*  Send events */

drivers/staging/comedi/drivers/comedi_fc.c

@@ -75,7 +75,7 @@ unsigned int cfc_write_array_to_buffer(struct comedi_subdevice *s,
 	}
 
 	comedi_buf_memcpy_to(s, 0, data, num_bytes);
-	comedi_buf_write_free(async, num_bytes);
+	comedi_buf_write_free(s, num_bytes);
 	cfc_inc_scan_progress(s, num_bytes);
 	async->events |= COMEDI_CB_BLOCK;
 

drivers/staging/comedi/drivers/mite.c

@@ -550,7 +550,7 @@ int mite_sync_input_dma(struct mite_channel *mite_chan,
 	if (count <= 0)
 		return 0;
 
-	comedi_buf_write_free(async, count);
+	comedi_buf_write_free(s, count);
 	cfc_inc_scan_progress(s, count);
 	async->events |= COMEDI_CB_BLOCK;
 	return 0;