[ARM] 4177/1: S3C24XX: Add DMA channel allocation order

Allow the CPU code, and any board specific initialisation
code to change the allocation order of the DMA channels,
or stop a peripheral allocating any DMA at-all.

This is due to the scarce mapping of DMA channels on
some earlier S3C24XX cpus, where the selection changes
depending on the channel in use.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 25 insertions, 0 deletions

diff --git a/include/asm-arm/plat-s3c24xx/dma.h b/include/asm-arm/plat-s3c24xx/dma.h
index 421b567fa019..15e140c2d4fc 100644
--- a/include/asm-arm/plat-s3c24xx/dma.h
+++ b/include/asm-arm/plat-s3c24xx/dma.h
@@ -14,6 +14,7 @@ extern struct sysdev_class dma_sysclass;
 extern struct s3c2410_dma_chan s3c2410_chans[S3C2410_DMA_CHANNELS];
 
 #define DMA_CH_VALID		(1<<31)
+#define DMA_CH_NEVER		(1<<30)
 
 struct s3c24xx_dma_addr {
 	unsigned long		from;
@@ -43,3 +44,27 @@ struct s3c24xx_dma_selection {
 };
 
 extern int s3c24xx_dma_init_map(struct s3c24xx_dma_selection *sel);
+
+/* struct s3c24xx_dma_order_ch
+ *
+ * channel map for one of the `enum dma_ch` dma channels. the list
+ * entry contains a set of low-level channel numbers, orred with
+ * DMA_CH_VALID, which are checked in the order in the array.
+*/
+
+struct s3c24xx_dma_order_ch {
+	unsigned int	list[S3C2410_DMA_CHANNELS];	/* list of channels */
+	unsigned int	flags;				/* flags */
+};
+
+/* struct s3c24xx_dma_order
+ *
+ * information provided by either the core or the board to give the
+ * dma system a hint on how to allocate channels
+*/
+
+struct s3c24xx_dma_order {
+	struct s3c24xx_dma_order_ch	channels[DMACH_MAX];
+};
+
+extern int s3c24xx_dma_order_set(struct s3c24xx_dma_order *map);