LXR linux/include/linux/platform

   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 */
  39struct 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 */
  51struct 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 */
  66struct ep93xx_dma_platform_data {
  67        struct ep93xx_dma_chan_data     *channels;
  68        size_t                          num_channels;
  69};
  70
  71static 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 */
  84static inline enum dma_transfer_direction
  85ep93xx_dma_chan_direction(struct dma_chan *chan)
  86{
  87        if (!ep93xx_dma_chan_is_m2p(chan))
  88                return DMA_TRANS_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 */
  95