include/linux/platform_data/dma-ep93xx.h

   1 #ifndef __ASM_ARCH_DMA_H
   2 #define __ASM_ARCH_DMA_H
   3
   4 #include <linux/types.h>
   5 #include <linux/dmaengine.h>
   6 #include <linux/dma-mapping.h>
   7
   8 /*
   9  * M2P channels.
  10  *
  11  * Note that these values are also directly used for setting the PPALLOC
  12  * register.
  13  */
  14 #define EP93XX_DMA_I2S1         0
  15 #define EP93XX_DMA_I2S2         1
  16 #define EP93XX_DMA_AAC1         2
  17 #define EP93XX_DMA_AAC2         3
  18 #define EP93XX_DMA_AAC3         4
  19 #define EP93XX_DMA_I2S3         5
  20 #define EP93XX_DMA_UART1        6
  21 #define EP93XX_DMA_UART2        7
  22 #define EP93XX_DMA_UART3        8
  23 #define EP93XX_DMA_IRDA         9
  24 /* M2M channels */
  25 #define EP93XX_DMA_SSP          10
  26 #define EP93XX_DMA_IDE          11
  27
  28 /**
  29  * struct ep93xx_dma_data - configuration data for the EP93xx dmaengine
  30  * @port: peripheral which is requesting the channel
  31  * @direction: TX/RX channel
  32  * @name: optional name for the channel, this is displayed in /proc/interrupts
  33  *
  34  * This information is passed as private channel parameter in a filter
  35  * function. Note that this is only needed for slave/cyclic channels.  For
  36  * memcpy channels %NULL data should be passed.
  37  */
  38 struct ep93xx_dma_data {
  39         int                             port;
  40         enum dma_transfer_direction     direction;
  41         const char                      *name;
  42 };
  43
  44 /**
  45  * struct ep93xx_dma_chan_data - platform specific data for a DMA channel
  46  * @name: name of the channel, used for getting the right clock for the channel
  47  * @base: mapped registers
  48  * @irq: interrupt number used by this channel
  49  */
  50 struct ep93xx_dma_chan_data {
  51         const char                      *name;
  52         void __iomem                    *base;
  53         int                             irq;
  54 };
  55
  56 /**
  57  * struct ep93xx_dma_platform_data - platform data for the dmaengine driver
  58  * @channels: array of channels which are passed to the driver
  59  * @num_channels: number of channels in the array
  60  *
  61  * This structure is passed to the DMA engine driver via platform data. For
  62  * M2P channels, contract is that even channels are for TX and odd for RX.
  63  * There is no requirement for the M2M channels.
  64  */
  65 struct ep93xx_dma_platform_data {
  66         struct ep93xx_dma_chan_data     *channels;
  67         size_t                          num_channels;
  68 };
  69
  70 static inline bool ep93xx_dma_chan_is_m2p(struct dma_chan *chan)
  71 {
  72         return !strcmp(dev_name(chan->device->dev), "ep93xx-dma-m2p");
  73 }
  74
  75 /**
  76  * ep93xx_dma_chan_direction - returns direction the channel can be used
  77  * @chan: channel
  78  *
  79  * This function can be used in filter functions to find out whether the
  80  * channel supports given DMA direction. Only M2P channels have such
  81  * limitation, for M2M channels the direction is configurable.
  82  */
  83 static inline enum dma_transfer_direction
  84 ep93xx_dma_chan_direction(struct dma_chan *chan)
  85 {
  86         if (!ep93xx_dma_chan_is_m2p(chan))
  87                 return DMA_NONE;
  88
  89         /* even channels are for TX, odd for RX */
  90         return (chan->chan_id % 2 == 0) ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
  91 }
  92
  93 #endif /* __ASM_ARCH_DMA_H */