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_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 */