include/linux/platform_data/dma-ep93xx.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __ASM_ARCH_DMA_H
   3 #define __ASM_ARCH_DMA_H
   4
   5 #include <linux/types.h>
   6 #include <linux/dmaengine.h>
   7 #include <linux/dma-mapping.h>
   8
   9 /*
  10  * M2P channels.
  11  *
  12  * Note that these values are also directly used for setting the PPALLOC
  13  * register.
  14  */
  15 #define EP93XX_DMA_I2S1         0
  16 #define EP93XX_DMA_I2S2         1
  17 #define EP93XX_DMA_AAC1         2
  18 #define EP93XX_DMA_AAC2         3
  19 #define EP93XX_DMA_AAC3         4
  20 #define EP93XX_DMA_I2S3         5
  21 #define EP93XX_DMA_UART1        6
  22 #define EP93XX_DMA_UART2        7
  23 #define EP93XX_DMA_UART3        8
  24 #define EP93XX_DMA_IRDA         9
  25 /* M2M channels */
  26 #define EP93XX_DMA_SSP          10
  27 #define EP93XX_DMA_IDE          11
  28
  29 /**
  30  * struct ep93xx_dma_data - configuration data for the EP93xx dmaengine
  31  * @port: peripheral which is requesting the channel
  32  * @direction: TX/RX channel
  33  * @name: optional name for the channel, this is displayed in /proc/interrupts
  34  *
  35  * This information is passed as private channel parameter in a filter
  36  * function. Note that this is only needed for slave/cyclic channels.  For
  37  * memcpy channels %NULL data should be passed.
  38  */
  39 struct ep93xx_dma_data {
  40         int                             port;
  41         enum dma_transfer_direction     direction;
  42         const char                      *name;
  43 };
  44
  45 /**
  46  * struct ep93xx_dma_chan_data - platform specific data for a DMA channel
  47  * @name: name of the channel, used for getting the right clock for the channel
  48  * @base: mapped registers
  49  * @irq: interrupt number used by this channel
  50  */
  51 struct ep93xx_dma_chan_data {
  52         const char                      *name;
  53         void __iomem                    *base;
  54         int                             irq;
  55 };
  56
  57 /**
  58  * struct ep93xx_dma_platform_data - platform data for the dmaengine driver
  59  * @channels: array of channels which are passed to the driver
  60  * @num_channels: number of channels in the array
  61  *
  62  * This structure is passed to the DMA engine driver via platform data. For
  63  * M2P channels, contract is that even channels are for TX and odd for RX.
  64  * There is no requirement for the M2M channels.
  65  */
  66 struct ep93xx_dma_platform_data {
  67         struct ep93xx_dma_chan_data     *channels;
  68         size_t                          num_channels;
  69 };
  70
  71 static inline bool ep93xx_dma_chan_is_m2p(struct dma_chan *chan)
  72 {
  73         return !strcmp(dev_name(chan->device->dev), "ep93xx-dma-m2p");
  74 }
  75
  76 /**
  77  * ep93xx_dma_chan_direction - returns direction the channel can be used
  78  * @chan: channel
  79  *
  80  * This function can be used in filter functions to find out whether the
  81  * channel supports given DMA direction. Only M2P channels have such
  82  * limitation, for M2M channels the direction is configurable.
  83  */
  84 static inline enum dma_transfer_direction
  85 ep93xx_dma_chan_direction(struct dma_chan *chan)
  86 {
  87         if (!ep93xx_dma_chan_is_m2p(chan))
  88                 return DMA_NONE;
  89
  90         /* even channels are for TX, odd for RX */
  91         return (chan->chan_id % 2 == 0) ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
  92 }
  93
  94 #endif /* __ASM_ARCH_DMA_H */