aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/usb/musb/musb_dma.h
blob: c8e67fde215655789dde9e0e01ed3fed54bffa9b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
/*
 * MUSB OTG driver DMA controller abstraction
 *
 * Copyright 2005 Mentor Graphics Corporation
 * Copyright (C) 2005-2006 by Texas Instruments
 * Copyright (C) 2006-2007 Nokia Corporation
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
 * NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#ifndef __MUSB_DMA_H__
#define __MUSB_DMA_H__

struct musb_hw_ep;

/*
 * DMA Controller Abstraction
 *
 * DMA Controllers are abstracted to allow use of a variety of different
 * implementations of DMA, as allowed by the Inventra USB cores.  On the
 * host side, usbcore sets up the DMA mappings and flushes caches; on the
 * peripheral side, the gadget controller driver does.  Responsibilities
 * of a DMA controller driver include:
 *
 *  - Handling the details of moving multiple USB packets
 *    in cooperation with the Inventra USB core, including especially
 *    the correct RX side treatment of short packets and buffer-full
 *    states (both of which terminate transfers).
 *
 *  - Knowing the correlation between dma channels and the
 *    Inventra core's local endpoint resources and data direction.
 *
 *  - Maintaining a list of allocated/available channels.
 *
 *  - Updating channel status on interrupts,
 *    whether shared with the Inventra core or separate.
 */

#define	DMA_ADDR_INVALID	(~(dma_addr_t)0)

#ifdef CONFIG_MUSB_PIO_ONLY
#define	is_dma_capable()	(0)
#else
#define	is_dma_capable()	(1)
#endif

#ifdef CONFIG_USB_TI_CPPI_DMA
#define	is_cppi_enabled()	1
#else
#define	is_cppi_enabled()	0
#endif

#ifdef CONFIG_USB_TUSB_OMAP_DMA
#define tusb_dma_omap()			1
#else
#define tusb_dma_omap()			0
#endif

/* Anomaly 05000456 - USB Receive Interrupt Is Not Generated in DMA Mode 1
 *	Only allow DMA mode 1 to be used when the USB will actually generate the
 *	interrupts we expect.
 */
#ifdef CONFIG_BLACKFIN
# undef USE_MODE1
# if !ANOMALY_05000456
#  define USE_MODE1
# endif
#endif

/*
 * DMA channel status ... updated by the dma controller driver whenever that
 * status changes, and protected by the overall controller spinlock.
 */
enum dma_channel_status {
	/* unallocated */
	MUSB_DMA_STATUS_UNKNOWN,
	/* allocated ... but not busy, no errors */
	MUSB_DMA_STATUS_FREE,
	/* busy ... transactions are active */
	MUSB_DMA_STATUS_BUSY,
	/* transaction(s) aborted due to ... dma or memory bus error */
	MUSB_DMA_STATUS_BUS_ABORT,
	/* transaction(s) aborted due to ... core error or USB fault */
	MUSB_DMA_STATUS_CORE_ABORT
};

struct dma_controller;

/**
 * struct dma_channel - A DMA channel.
 * @private_data: channel-private data
 * @max_len: the maximum number of bytes the channel can move in one
 *	transaction (typically representing many USB maximum-sized packets)
 * @actual_len: how many bytes have been transferred
 * @status: current channel status (updated e.g. on interrupt)
 * @desired_mode: true if mode 1 is desired; false if mode 0 is desired
 *
 * channels are associated with an endpoint for the duration of at least
 * one usb transfer.
 */
struct dma_channel {
	void			*private_data;
	/* FIXME not void* private_data, but a dma_controller * */
	size_t			max_len;
	size_t			actual_len;
	enum dma_channel_status	status;
	bool			desired_mode;
};

/*
 * dma_channel_status - return status of dma channel
 * @c: the channel
 *
 * Returns the software's view of the channel status.  If that status is BUSY
 * then it's possible that the hardware has completed (or aborted) a transfer,
 * so the driver needs to update that status.
 */
static inline enum dma_channel_status
dma_channel_status(struct dma_channel *c)
{
	return (is_dma_capable() && c) ? c->status : MUSB_DMA_STATUS_UNKNOWN;
}

/**
 * struct dma_controller - A DMA Controller.
 * @start: call this to start a DMA controller;
 *	return 0 on success, else negative errno
 * @stop: call this to stop a DMA controller
 *	return 0 on success, else negative errno
 * @channel_alloc: call this to allocate a DMA channel
 * @channel_release: call this to release a DMA channel
 * @channel_abort: call this to abort a pending DMA transaction,
 *	returning it to FREE (but allocated) state
 *
 * Controllers manage dma channels.
 */
struct dma_controller {
	struct dma_channel	*(*channel_alloc)(struct dma_controller *,
					struct musb_hw_ep *, u8 is_tx);
	void			(*channel_release)(struct dma_channel *);
	int			(*channel_program)(struct dma_channel *channel,
							u16 maxpacket, u8 mode,
							dma_addr_t dma_addr,
							u32 length);
	int			(*channel_abort)(struct dma_channel *);
	int			(*is_compatible)(struct dma_channel *channel,
							u16 maxpacket,
							void *buf, u32 length);
};

/* called after channel_program(), may indicate a fault */
extern void musb_dma_completion(struct musb *musb, u8 epnum, u8 transmit);

#ifdef CONFIG_MUSB_PIO_ONLY
static inline struct dma_controller *dma_controller_create(struct musb *m,
		void __iomem *io)
{
	return NULL;
}

static inline void dma_controller_destroy(struct dma_controller *d) { }

#else

extern struct dma_controller *dma_controller_create(struct musb *, void __iomem *);

extern void dma_controller_destroy(struct dma_controller *);
#endif

#endif	/* __MUSB_DMA_H__ */

Privacy Policy