diff options
Diffstat (limited to 'Documentation/arm')
-rw-r--r-- | Documentation/arm/Samsung-S3C24XX/DMA.txt | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/Documentation/arm/Samsung-S3C24XX/DMA.txt b/Documentation/arm/Samsung-S3C24XX/DMA.txt index 37f4edcc5d87..3ed82383efea 100644 --- a/Documentation/arm/Samsung-S3C24XX/DMA.txt +++ b/Documentation/arm/Samsung-S3C24XX/DMA.txt | |||
@@ -5,7 +5,7 @@ Introduction | |||
5 | ------------ | 5 | ------------ |
6 | 6 | ||
7 | The kernel provides an interface to manage DMA transfers | 7 | The kernel provides an interface to manage DMA transfers |
8 | using the DMA channels in the cpu, so that the central | 8 | using the DMA channels in the CPU, so that the central |
9 | duty of managing channel mappings, and programming the | 9 | duty of managing channel mappings, and programming the |
10 | channel generators is in one place. | 10 | channel generators is in one place. |
11 | 11 | ||
@@ -17,24 +17,24 @@ DMA Channel Ordering | |||
17 | channels to all sources, which means that some devices | 17 | channels to all sources, which means that some devices |
18 | have a restricted number of channels that can be used. | 18 | have a restricted number of channels that can be used. |
19 | 19 | ||
20 | To allow flexibilty for each cpu type and board, the | 20 | To allow flexibility for each CPU type and board, the |
21 | dma code can be given an dma ordering structure which | 21 | DMA code can be given a DMA ordering structure which |
22 | allows the order of channel search to be specified, as | 22 | allows the order of channel search to be specified, as |
23 | well as allowing the prohibition of certain claims. | 23 | well as allowing the prohibition of certain claims. |
24 | 24 | ||
25 | struct s3c24xx_dma_order has a list of channels, and | 25 | struct s3c24xx_dma_order has a list of channels, and |
26 | each channel within has a slot for a list of dma | 26 | each channel within has a slot for a list of DMA |
27 | channel numbers. The slots are searched in order, for | 27 | channel numbers. The slots are searched in order for |
28 | the presence of a dma channel number with DMA_CH_VALID | 28 | the presence of a DMA channel number with DMA_CH_VALID |
29 | orred in. | 29 | or-ed in. |
30 | 30 | ||
31 | If the order has the flag DMA_CH_NEVER set, then after | 31 | If the order has the flag DMA_CH_NEVER set, then after |
32 | checking the channel list, the system will return no | 32 | checking the channel list, the system will return no |
33 | found channel, thus denying the request. | 33 | found channel, thus denying the request. |
34 | 34 | ||
35 | A board support file can call s3c24xx_dma_order_set() | 35 | A board support file can call s3c24xx_dma_order_set() |
36 | to register an complete ordering set. The routine will | 36 | to register a complete ordering set. The routine will |
37 | copy the data, so the original can be discared with | 37 | copy the data, so the original can be discarded with |
38 | __initdata. | 38 | __initdata. |
39 | 39 | ||
40 | 40 | ||