EDMA interface renames: edma_link(), edma_unlink()

Another EDMA interface update.  Fixes documentation for the linking
calls to be kerneldoc style.  Rename parameters so they're meaningful
(from/to vs lch/lch_que) and unsigned (eliminates some error checks).
Remove unused edma_unlink() parameter.  Move this code so it's grouped
with the other calls which only modify parameter RAM.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

arch/arm/mach-davinci/dma.c

@@ -909,6 +909,38 @@ void davinci_set_dma_transfer_params(int lch,
 }
 EXPORT_SYMBOL(davinci_set_dma_transfer_params);
 
+/**
+ * edma_link - link one parameter RAM slot to another
+ * @from: parameter RAM slot originating the link
+ * @to: parameter RAM slot which is the link target
+ *
+ * The originating slot should not be part of any active DMA transfer.
+ */
+void edma_link(unsigned from, unsigned to)
+{
+	if (from >= DAVINCI_EDMA_NUM_PARAMENTRY)
+		return;
+	if (to >= DAVINCI_EDMA_NUM_PARAMENTRY)
+		return;
+	edma_parm_modify(PARM_LINK_BCNTRLD, from, 0xffff0000, PARM_OFFSET(to));
+}
+EXPORT_SYMBOL(edma_link);
+
+/**
+ * edma_unlink - cut link from one parameter RAM slot
+ * @from: parameter RAM slot originating the link
+ *
+ * The originating slot should not be part of any active DMA transfer.
+ * Its link is set to 0xffff.
+ */
+void edma_unlink(unsigned from)
+{
+	if (from >= DAVINCI_EDMA_NUM_PARAMENTRY)
+		return;
+	edma_parm_or(PARM_LINK_BCNTRLD, from, 0xffff);
+}
+EXPORT_SYMBOL(edma_unlink);
+
 /*-----------------------------------------------------------------------*/
 
 /* Parameter RAM operations (ii) -- read/write whole parameter sets */
@@ -1060,49 +1092,6 @@ void davinci_stop_dma(int lch)
 }
 EXPORT_SYMBOL(davinci_stop_dma);
 
-/******************************************************************************
- *
- * DMA channel link - link the two logical channels passed through by linking
- *		the link field of head to the param pointed by the lch_que.
- * ARGUMENTS:
- * lch  - logical channel number, in which the link field is linked
- *                  to the param pointed to by lch_que
- * lch_que - logical channel number or the param entry number, which is to be
- *                  linked to the lch
- *
- *****************************************************************************/
-void davinci_dma_link_lch(int lch, int lch_que)
-{
-	if ((lch >= 0) && (lch < DAVINCI_EDMA_NUM_PARAMENTRY) &&
-	    (lch_que >= 0) && (lch_que < DAVINCI_EDMA_NUM_PARAMENTRY)) {
-		/* program LINK */
-		edma_parm_modify(PARM_LINK_BCNTRLD, lch,
-				0xffff0000,
-				PARM_OFFSET(lch_que));
-	}
-}
-EXPORT_SYMBOL(davinci_dma_link_lch);
-
-/******************************************************************************
- *
- * DMA channel unlink - unlink the two logical channels passed through by
- *                   setting the link field of head to 0xffff.
- * ARGUMENTS:
- * lch - logical channel number, from which the link field is to be removed
- * lch_que - logical channel number or the param entry number, which is to be
- *             unlinked from lch
- *
- *****************************************************************************/
-void davinci_dma_unlink_lch(int lch, int lch_que)
-{
-	if ((lch >= 0) && (lch < DAVINCI_EDMA_NUM_PARAMENTRY) &&
-	    (lch_que >= 0) && (lch_que < DAVINCI_EDMA_NUM_PARAMENTRY)) {
-		edma_parm_or(PARM_LINK_BCNTRLD, lch,
-				0xffff);
-	}
-}
-EXPORT_SYMBOL(davinci_dma_unlink_lch);
-
 /******************************************************************************
  *
  * It cleans ParamEntry qand bring back EDMA to initial state if media has

arch/arm/mach-davinci/include/mach/edma.h

@@ -190,6 +190,7 @@ int davinci_request_dma(int dev_id, const char *dev_name,
 	void *data, int *lch, int *tcc, enum dma_event_q);
 void davinci_free_dma(int lch);
 
+/* calls that operate on part of a parameter RAM slot */
 void davinci_set_dma_src_params(int lch, dma_addr_t src_port,
 				enum address_mode mode, enum fifo_width);
 void davinci_set_dma_dest_params(int lch, dma_addr_t dest_port,
@@ -198,49 +199,16 @@ void davinci_set_dma_src_index(int lch, s16 src_bidx, s16 src_cidx);
 void davinci_set_dma_dest_index(int lch, s16 dest_bidx, s16 dest_cidx);
 void davinci_set_dma_transfer_params(int lch, u16 acnt, u16 bcnt, u16 ccnt,
 		u16 bcnt_rld, enum sync_dimension sync_mode);
+void edma_link(unsigned from, unsigned to);
+void edma_unlink(unsigned from);
 
+/* calls that operate on an entire parameter RAM slot */
 void edma_write_slot(unsigned slot, const struct edmacc_param *params);
 void edma_read_slot(unsigned slot, struct edmacc_param *params);
 
 int davinci_start_dma(int lch);
 void davinci_stop_dma(int lch);
 
-/******************************************************************************
- * davinci_dma_link_lch - Link two Logical channels
- *
- * lch_head  - logical channel number, in which the link field is linked to the
- *             the param pointed to by lch_queue
- *             Can be a MasterChannel or SlaveChannel
- * lch_queue - logical channel number or the param entry number, which is to be
- *             linked to the lch_head
- *             Must be a SlaveChannel
- *
- *                     |---------------|
- *                     v               |
- *      Ex:    ch1--> ch2-->ch3-->ch4--|
- *
- *             ch1 must be a MasterChannel
- *
- *             ch2, ch3, ch4 must be SlaveChannels
- *
- * Note:       After channel linking,the user should not update any PaRam entry
- *             of MasterChannel ( In the above example ch1 )
- *
- *****************************************************************************/
-void davinci_dma_link_lch(int lch_head, int lch_queue);
-
-/******************************************************************************
- * davinci_dma_unlink_lch - unlink the two logical channels passed through by
- *                          setting the link field of head to 0xffff.
- *
- * lch_head  - logical channel number, from which the link field is to be
- *             removed
- * lch_queue - logical channel number or the param entry number,which is to be
- *             unlinked from lch_head
- *
- *****************************************************************************/
-void davinci_dma_unlink_lch(int lch_head, int lch_queue);
-
 void davinci_dma_getposition(int lch, dma_addr_t *src, dma_addr_t *dst);
 void davinci_clean_channel(int lch);
 void davinci_pause_dma(int lch);

sound/soc/davinci/davinci-pcm.c

@@ -156,7 +156,7 @@ static int davinci_pcm_dma_request(struct snd_pcm_substream *substream)
 	}
 
 	/* Link parameter RAM to itself in loopback */
-	davinci_dma_link_lch(prtd->slave_lch, prtd->slave_lch);
+	edma_link(prtd->slave_lch, prtd->slave_lch);
 
 	return 0;
 }
@@ -260,7 +260,7 @@ static int davinci_pcm_close(struct snd_pcm_substream *substream)
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct davinci_runtime_data *prtd = runtime->private_data;
 
-	davinci_dma_unlink_lch(prtd->slave_lch, prtd->slave_lch);
+	edma_unlink(prtd->slave_lch);
 
 	davinci_free_dma(prtd->slave_lch);
 	davinci_free_dma(prtd->master_lch);