1 /* SPDX-License-Identifier: GPL-2.0
2 *
3 * Dmaengine driver base library for DMA controllers, found on SH-based SoCs
4 *
5 * extracted from shdma.c and headers
6 *
7 * Copyright (C) 2011-2012 Guennadi Liakhovetski <g.liakhovetski@gmx.de>
8 * Copyright (C) 2009 Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
9 * Copyright (C) 2009 Renesas Solutions, Inc. All rights reserved.
10 * Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved.
11 */
12
13 #ifndef SHDMA_BASE_H
14 #define SHDMA_BASE_H
15
16 #include <linux/dmaengine.h>
17 #include <linux/interrupt.h>
18 #include <linux/list.h>
19 #include <linux/types.h>
20
21 /**
22 * shdma_pm_state - DMA channel PM state
23 * SHDMA_PM_ESTABLISHED: either idle or during data transfer
24 * SHDMA_PM_BUSY: during the transfer preparation, when we have to
25 * drop the lock temporarily
26 * SHDMA_PM_PENDING: transfers pending
27 */
28 enum shdma_pm_state {
29 SHDMA_PM_ESTABLISHED,
30 SHDMA_PM_BUSY,
31 SHDMA_PM_PENDING,
32 };
33
34 struct device;
35
36 /*
37 * Drivers, using this library are expected to embed struct shdma_dev,
38 * struct shdma_chan, struct shdma_desc, and struct shdma_slave
39 * in their respective device, channel, descriptor and slave objects.
40 */
41
42 struct shdma_slave {
43 int slave_id;
44 };
45
46 struct shdma_desc {
47 struct list_head node;
48 struct dma_async_tx_descriptor async_tx;
49 enum dma_transfer_direction direction;
50 size_t partial;
51 dma_cookie_t cookie;
52 int chunks;
53 int mark;
54 bool cyclic; /* used as cyclic transfer */
55 };
56
57 struct shdma_chan {
58 spinlock_t chan_lock; /* Channel operation lock */
59 struct list_head ld_queue; /* Link descriptors queue */
60 struct list_head ld_free; /* Free link descriptors */
61 struct dma_chan dma_chan; /* DMA channel */
62 struct device *dev; /* Channel device */
63 void *desc; /* buffer for descriptor array */
64 int desc_num; /* desc count */
65 size_t max_xfer_len; /* max transfer length */
66 int id; /* Raw id of this channel */
67 int irq; /* Channel IRQ */
68 int slave_id; /* Client ID for slave DMA */
69 int real_slave_id; /* argument passed to filter function */
70 int hw_req; /* DMA request line for slave DMA - same
71 * as MID/RID, used with DT */
72 enum shdma_pm_state pm_state;
73 };
74
75 /**
76 * struct shdma_ops - simple DMA driver operations
77 * desc_completed: return true, if this is the descriptor, that just has
78 * completed (atomic)
79 * halt_channel: stop DMA channel operation (atomic)
80 * channel_busy: return true, if the channel is busy (atomic)
81 * slave_addr: return slave DMA address
82 * desc_setup: set up the hardware specific descriptor portion (atomic)
83 * set_slave: bind channel to a slave
84 * setup_xfer: configure channel hardware for operation (atomic)
85 * start_xfer: start the DMA transfer (atomic)
86 * embedded_desc: return Nth struct shdma_desc pointer from the
87 * descriptor array
88 * chan_irq: process channel IRQ, return true if a transfer has
89 * completed (atomic)
90 */
91 struct shdma_ops {
92 bool (*desc_completed)(struct shdma_chan *, struct shdma_desc *);
93 void (*halt_channel)(struct shdma_chan *);
94 bool (*channel_busy)(struct shdma_chan *);
95 dma_addr_t (*slave_addr)(struct shdma_chan *);
96 int (*desc_setup)(struct shdma_chan *, struct shdma_desc *,
97 dma_addr_t, dma_addr_t, size_t *);
98 int (*set_slave)(struct shdma_chan *, int, dma_addr_t, bool);
99 void (*setup_xfer)(struct shdma_chan *, int);
100 void (*start_xfer)(struct shdma_chan *, struct shdma_desc *);
101 struct shdma_desc *(*embedded_desc)(void *, int);
102 bool (*chan_irq)(struct shdma_chan *, int);
103 size_t (*get_partial)(struct shdma_chan *, struct shdma_desc *);
104 };
105
106 struct shdma_dev {
107 struct dma_device dma_dev;
108 struct shdma_chan **schan;
109 const struct shdma_ops *ops;
110 size_t desc_size;
111 };
112
113 #define shdma_for_each_chan(c, d, i) for (i = 0, c = (d)->schan[0]; \
114 i < (d)->dma_dev.chancnt; c = (d)->schan[++i])
115
116 int shdma_request_irq(struct shdma_chan *, int,
117 unsigned long, const char *);
118 bool shdma_reset(struct shdma_dev *sdev);
119 void shdma_chan_probe(struct shdma_dev *sdev,
120 struct shdma_chan *schan, int id);
121 void shdma_chan_remove(struct shdma_chan *schan);
122 int shdma_init(struct device *dev, struct shdma_dev *sdev,
123 int chan_num);
124 void shdma_cleanup(struct shdma_dev *sdev);
125 #if IS_ENABLED(CONFIG_SH_DMAE_BASE)
126 bool shdma_chan_filter(struct dma_chan *chan, void *arg);
127 #else
shdma_chan_filter(struct dma_chan * chan,void * arg)128 static inline bool shdma_chan_filter(struct dma_chan *chan, void *arg)
129 {
130 return false;
131 }
132 #endif
133
134 #endif
135