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musb_dma.h
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1 /*
2  * MUSB OTG driver DMA controller abstraction
3  *
4  * Copyright 2005 Mentor Graphics Corporation
5  * Copyright (C) 2005-2006 by Texas Instruments
6  * Copyright (C) 2006-2007 Nokia Corporation
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License
10  * version 2 as published by the Free Software Foundation.
11  *
12  * This program is distributed in the hope that it will be useful, but
13  * WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20  * 02110-1301 USA
21  *
22  * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
23  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
24  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
25  * NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
28  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
29  * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  *
33  */
34 
35 #ifndef __MUSB_DMA_H__
36 #define __MUSB_DMA_H__
37 
38 struct musb_hw_ep;
39 
40 /*
41  * DMA Controller Abstraction
42  *
43  * DMA Controllers are abstracted to allow use of a variety of different
44  * implementations of DMA, as allowed by the Inventra USB cores. On the
45  * host side, usbcore sets up the DMA mappings and flushes caches; on the
46  * peripheral side, the gadget controller driver does. Responsibilities
47  * of a DMA controller driver include:
48  *
49  * - Handling the details of moving multiple USB packets
50  * in cooperation with the Inventra USB core, including especially
51  * the correct RX side treatment of short packets and buffer-full
52  * states (both of which terminate transfers).
53  *
54  * - Knowing the correlation between dma channels and the
55  * Inventra core's local endpoint resources and data direction.
56  *
57  * - Maintaining a list of allocated/available channels.
58  *
59  * - Updating channel status on interrupts,
60  * whether shared with the Inventra core or separate.
61  */
62 
63 #define DMA_ADDR_INVALID (~(dma_addr_t)0)
64 
65 #ifndef CONFIG_MUSB_PIO_ONLY
66 #define is_dma_capable() (1)
67 #else
68 #define is_dma_capable() (0)
69 #endif
70 
71 #ifdef CONFIG_USB_TI_CPPI_DMA
72 #define is_cppi_enabled() 1
73 #else
74 #define is_cppi_enabled() 0
75 #endif
76 
77 #ifdef CONFIG_USB_TUSB_OMAP_DMA
78 #define tusb_dma_omap() 1
79 #else
80 #define tusb_dma_omap() 0
81 #endif
82 
83 /* Anomaly 05000456 - USB Receive Interrupt Is Not Generated in DMA Mode 1
84  * Only allow DMA mode 1 to be used when the USB will actually generate the
85  * interrupts we expect.
86  */
87 #ifdef CONFIG_BLACKFIN
88 # undef USE_MODE1
89 # if !ANOMALY_05000456
90 # define USE_MODE1
91 # endif
92 #endif
93 
94 /*
95  * DMA channel status ... updated by the dma controller driver whenever that
96  * status changes, and protected by the overall controller spinlock.
97  */
99  /* unallocated */
101  /* allocated ... but not busy, no errors */
103  /* busy ... transactions are active */
105  /* transaction(s) aborted due to ... dma or memory bus error */
107  /* transaction(s) aborted due to ... core error or USB fault */
109 };
110 
111 struct dma_controller;
112 
125 struct dma_channel {
127  /* FIXME not void* private_data, but a dma_controller * */
128  size_t max_len;
129  size_t actual_len;
132 };
133 
134 /*
135  * dma_channel_status - return status of dma channel
136  * @c: the channel
137  *
138  * Returns the software's view of the channel status. If that status is BUSY
139  * then it's possible that the hardware has completed (or aborted) a transfer,
140  * so the driver needs to update that status.
141  */
142 static inline enum dma_channel_status
144 {
145  return (is_dma_capable() && c) ? c->status : MUSB_DMA_STATUS_UNKNOWN;
146 }
147 
162  int (*start)(struct dma_controller *);
163  int (*stop)(struct dma_controller *);
164  struct dma_channel *(*channel_alloc)(struct dma_controller *,
165  struct musb_hw_ep *, u8 is_tx);
168  u16 maxpacket, u8 mode,
170  u32 length);
173  u16 maxpacket,
174  void *buf, u32 length);
175 };
176 
177 /* called after channel_program(), may indicate a fault */
178 extern void musb_dma_completion(struct musb *musb, u8 epnum, u8 transmit);
179 
180 
181 extern struct dma_controller *__devinit
182 dma_controller_create(struct musb *, void __iomem *);
183 
184 extern void dma_controller_destroy(struct dma_controller *);
185 
186 #endif /* __MUSB_DMA_H__ */