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 */
28enum shdma_pm_state {
29	SHDMA_PM_ESTABLISHED,
30	SHDMA_PM_BUSY,
31	SHDMA_PM_PENDING,
32};
33
34struct 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
42struct shdma_slave {
43	int slave_id;
44};
45
46struct 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
57struct 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 */
91struct 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
106struct 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
116int shdma_request_irq(struct shdma_chan *, int,
117			   unsigned long, const char *);
118bool shdma_reset(struct shdma_dev *sdev);
119void shdma_chan_probe(struct shdma_dev *sdev,
120			   struct shdma_chan *schan, int id);
121void shdma_chan_remove(struct shdma_chan *schan);
122int shdma_init(struct device *dev, struct shdma_dev *sdev,
123		    int chan_num);
124void shdma_cleanup(struct shdma_dev *sdev);
125#if IS_ENABLED(CONFIG_SH_DMAE_BASE)
126bool shdma_chan_filter(struct dma_chan *chan, void *arg);
127#else
128static inline bool shdma_chan_filter(struct dma_chan *chan, void *arg)
129{
130	return false;
131}
132#endif
133
134#endif
135