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author | Mika Westerberg <mika.westerberg@iki.fi> | 2011-05-29 13:10:02 +0300 |
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committer | Grant Likely <grant.likely@secretlab.ca> | 2011-06-08 15:10:44 -0600 |
commit | 760ee1c4aafac8fcaf3be5ff2b19c5485c5886e1 (patch) | |
tree | fc8408001ecba7a7b575f8fa839fcc6989f852bb /arch/arm/mach-ep93xx/include | |
parent | b6336ca2982ccac98d9d017426c53ff1e13c017f (diff) | |
download | op-kernel-dev-760ee1c4aafac8fcaf3be5ff2b19c5485c5886e1.zip op-kernel-dev-760ee1c4aafac8fcaf3be5ff2b19c5485c5886e1.tar.gz |
dmaengine: add ep93xx DMA support
The ep93xx DMA controller has 10 independent memory to peripheral (M2P)
channels, and 2 dedicated memory to memory (M2M) channels. M2M channels can
also be used by SPI and IDE to perform DMA transfers to/from their memory
mapped FIFOs.
This driver supports both M2P and M2M channels with DMA_SLAVE, DMA_CYCLIC and
DMA_MEMCPY (M2M only) capabilities.
Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Signed-off-by: Ryan Mallon <rmallon@gmail.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'arch/arm/mach-ep93xx/include')
-rw-r--r-- | arch/arm/mach-ep93xx/include/mach/dma.h | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/arch/arm/mach-ep93xx/include/mach/dma.h b/arch/arm/mach-ep93xx/include/mach/dma.h index 5e31b2b..6e7049a 100644 --- a/arch/arm/mach-ep93xx/include/mach/dma.h +++ b/arch/arm/mach-ep93xx/include/mach/dma.h @@ -15,6 +15,8 @@ #include <linux/list.h> #include <linux/types.h> +#include <linux/dmaengine.h> +#include <linux/dma-mapping.h> /** * struct ep93xx_dma_buffer - Information about a buffer to be transferred @@ -146,4 +148,89 @@ void ep93xx_dma_m2p_submit_recursive(struct ep93xx_dma_m2p_client *m2p, */ void ep93xx_dma_m2p_flush(struct ep93xx_dma_m2p_client *m2p); +/* + * M2P channels. + * + * Note that these values are also directly used for setting the PPALLOC + * register. + */ +#define EP93XX_DMA_I2S1 0 +#define EP93XX_DMA_I2S2 1 +#define EP93XX_DMA_AAC1 2 +#define EP93XX_DMA_AAC2 3 +#define EP93XX_DMA_AAC3 4 +#define EP93XX_DMA_I2S3 5 +#define EP93XX_DMA_UART1 6 +#define EP93XX_DMA_UART2 7 +#define EP93XX_DMA_UART3 8 +#define EP93XX_DMA_IRDA 9 +/* M2M channels */ +#define EP93XX_DMA_SSP 10 +#define EP93XX_DMA_IDE 11 + +/** + * struct ep93xx_dma_data - configuration data for the EP93xx dmaengine + * @port: peripheral which is requesting the channel + * @direction: TX/RX channel + * @name: optional name for the channel, this is displayed in /proc/interrupts + * + * This information is passed as private channel parameter in a filter + * function. Note that this is only needed for slave/cyclic channels. For + * memcpy channels %NULL data should be passed. + */ +struct ep93xx_dma_data { + int port; + enum dma_data_direction direction; + const char *name; +}; + +/** + * struct ep93xx_dma_chan_data - platform specific data for a DMA channel + * @name: name of the channel, used for getting the right clock for the channel + * @base: mapped registers + * @irq: interrupt number used by this channel + */ +struct ep93xx_dma_chan_data { + const char *name; + void __iomem *base; + int irq; +}; + +/** + * struct ep93xx_dma_platform_data - platform data for the dmaengine driver + * @channels: array of channels which are passed to the driver + * @num_channels: number of channels in the array + * + * This structure is passed to the DMA engine driver via platform data. For + * M2P channels, contract is that even channels are for TX and odd for RX. + * There is no requirement for the M2M channels. + */ +struct ep93xx_dma_platform_data { + struct ep93xx_dma_chan_data *channels; + size_t num_channels; +}; + +static inline bool ep93xx_dma_chan_is_m2p(struct dma_chan *chan) +{ + return !strcmp(dev_name(chan->device->dev), "ep93xx-dma-m2p"); +} + +/** + * ep93xx_dma_chan_direction - returns direction the channel can be used + * @chan: channel + * + * This function can be used in filter functions to find out whether the + * channel supports given DMA direction. Only M2P channels have such + * limitation, for M2M channels the direction is configurable. + */ +static inline enum dma_data_direction +ep93xx_dma_chan_direction(struct dma_chan *chan) +{ + if (!ep93xx_dma_chan_is_m2p(chan)) + return DMA_NONE; + + /* even channels are for TX, odd for RX */ + return (chan->chan_id % 2 == 0) ? DMA_TO_DEVICE : DMA_FROM_DEVICE; +} + #endif /* __ASM_ARCH_DMA_H */ |