DMA part: No old API dropped. Add the s3c2410_dma_trigger() API used for
to start or to stop a DMA transfer. This API will reduce the miss use of
s3c2410_dma_started() function. User should provide the callback
functions, trigger event and the DMA channel number before calling this
API. These private data is packed in struct s3c2410_dma_client. No new
struct added.
--- a/arch/arm/plat-s3c/include/plat/dma.h 2009-08-24 13:29:03.000000000 +0800
+++ b/arch/arm/plat-s3c/include/plat/dma.h 2009-08-24 15:30:23.000000000 +0800
@@ -37,8 +37,23 @@
S3C2410_DMAOP_STARTED, /* indicate channel started */
};
+enum s3c2410_dma_trigger_event {
+ S3C2410_DMA_TRIGGER_START, /* start a channel */
+ S3C2410_DMA_TRIGGER_STOP, /* stop a channel */
+ S3C2410_DMA_TRIGGER_MAX,
+};
+
struct s3c2410_dma_client {
- char *name;
+ char *name;
+ unsigned int channel; /* channel number */
+ /* trigger event */
+ enum s3c2410_dma_trigger_event event;
+ /* callback funtion from client to generate the DMA REQ signal */
+ int (*gen_request)(void *);
+ /* callback funtion from client to end the DMA request */
+ int (*end_request)(void *);
+ /* pravate data to the callback function */
+ void *private_data;
};
struct s3c2410_dma_chan;
@@ -73,6 +88,13 @@
extern int s3c2410_dma_ctrl(unsigned int channel, enum s3c2410_chan_op op);
+/* s3c2410_dma_trigger
+ *
+ * trigger the DMA engine to start or stop
+*/
+
+extern int s3c2410_dma_trigger(struct s3c2410_dma_client *client);
+
/* s3c2410_dma_setflags
*
* set the channel's flags to a given state
--- a/arch/arm/plat-s3c/dma.c 2009-08-24 15:26:07.000000000 +0800
+++ b/arch/arm/plat-s3c/dma.c 2009-08-24 15:27:09.000000000 +0800
@@ -84,3 +84,32 @@
return 0;
}
EXPORT_SYMBOL(s3c2410_dma_setflags);
+
+int s3c2410_dma_trigger(struct s3c2410_dma_client *client)
+{
+ int ret = 0;
+ if(!client || !(client->channel < DMACH_MAX)) {
+ pr_debug("%s: Invalid parameter\n", __func__);
+ return -EINVAL;
+ }
+
+ switch(client->event) {
+ case S3C2410_DMA_TRIGGER_START:
+ s3c2410_dma_ctrl(client->channel, S3C2410_DMAOP_START);
+ if(client->gen_request)
+ ret = client->gen_request(client->private_data);
+ s3c2410_dma_ctrl(client->channel, S3C2410_DMAOP_STARTED);
+ return ret;
+ case S3C2410_DMA_TRIGGER_STOP:
+ s3c2410_dma_ctrl(client->channel, S3C2410_DMAOP_STOP);
+ if(client->end_request)
+ ret = client->end_request(client->private_data);
+ return ret;
+ default:
+ pr_debug("%s: Invalid event\n", __func__);
+ }
+ return -EINVAL;
+}
+
+EXPORT_SYMBOL(s3c2410_dma_trigger);
+
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