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14#include <linux/module.h>
15#include <linux/init.h>
16#include <linux/spinlock.h>
17#include <linux/errno.h>
18#include <linux/scatterlist.h>
19
20#include <asm/dma.h>
21
22#include <asm/mach/dma.h>
23
24DEFINE_SPINLOCK(dma_spin_lock);
25EXPORT_SYMBOL(dma_spin_lock);
26
27static dma_t *dma_chan[MAX_DMA_CHANNELS];
28
29static inline dma_t *dma_channel(unsigned int chan)
30{
31 if (chan >= MAX_DMA_CHANNELS)
32 return NULL;
33
34 return dma_chan[chan];
35}
36
37int __init isa_dma_add(unsigned int chan, dma_t *dma)
38{
39 if (!dma->d_ops)
40 return -EINVAL;
41
42 sg_init_table(&dma->buf, 1);
43
44 if (dma_chan[chan])
45 return -EBUSY;
46 dma_chan[chan] = dma;
47 return 0;
48}
49
50
51
52
53
54
55int request_dma(unsigned int chan, const char *device_id)
56{
57 dma_t *dma = dma_channel(chan);
58 int ret;
59
60 if (!dma)
61 goto bad_dma;
62
63 if (xchg(&dma->lock, 1) != 0)
64 goto busy;
65
66 dma->device_id = device_id;
67 dma->active = 0;
68 dma->invalid = 1;
69
70 ret = 0;
71 if (dma->d_ops->request)
72 ret = dma->d_ops->request(chan, dma);
73
74 if (ret)
75 xchg(&dma->lock, 0);
76
77 return ret;
78
79bad_dma:
80 printk(KERN_ERR "dma: trying to allocate DMA%d\n", chan);
81 return -EINVAL;
82
83busy:
84 return -EBUSY;
85}
86EXPORT_SYMBOL(request_dma);
87
88
89
90
91
92
93void free_dma(unsigned int chan)
94{
95 dma_t *dma = dma_channel(chan);
96
97 if (!dma)
98 goto bad_dma;
99
100 if (dma->active) {
101 printk(KERN_ERR "dma%d: freeing active DMA\n", chan);
102 dma->d_ops->disable(chan, dma);
103 dma->active = 0;
104 }
105
106 if (xchg(&dma->lock, 0) != 0) {
107 if (dma->d_ops->free)
108 dma->d_ops->free(chan, dma);
109 return;
110 }
111
112 printk(KERN_ERR "dma%d: trying to free free DMA\n", chan);
113 return;
114
115bad_dma:
116 printk(KERN_ERR "dma: trying to free DMA%d\n", chan);
117}
118EXPORT_SYMBOL(free_dma);
119
120
121
122void set_dma_sg (unsigned int chan, struct scatterlist *sg, int nr_sg)
123{
124 dma_t *dma = dma_channel(chan);
125
126 if (dma->active)
127 printk(KERN_ERR "dma%d: altering DMA SG while "
128 "DMA active\n", chan);
129
130 dma->sg = sg;
131 dma->sgcount = nr_sg;
132 dma->invalid = 1;
133}
134EXPORT_SYMBOL(set_dma_sg);
135
136
137
138
139
140void __set_dma_addr (unsigned int chan, void *addr)
141{
142 dma_t *dma = dma_channel(chan);
143
144 if (dma->active)
145 printk(KERN_ERR "dma%d: altering DMA address while "
146 "DMA active\n", chan);
147
148 dma->sg = NULL;
149 dma->addr = addr;
150 dma->invalid = 1;
151}
152EXPORT_SYMBOL(__set_dma_addr);
153
154
155
156
157
158void set_dma_count (unsigned int chan, unsigned long count)
159{
160 dma_t *dma = dma_channel(chan);
161
162 if (dma->active)
163 printk(KERN_ERR "dma%d: altering DMA count while "
164 "DMA active\n", chan);
165
166 dma->sg = NULL;
167 dma->count = count;
168 dma->invalid = 1;
169}
170EXPORT_SYMBOL(set_dma_count);
171
172
173
174void set_dma_mode (unsigned int chan, unsigned int mode)
175{
176 dma_t *dma = dma_channel(chan);
177
178 if (dma->active)
179 printk(KERN_ERR "dma%d: altering DMA mode while "
180 "DMA active\n", chan);
181
182 dma->dma_mode = mode;
183 dma->invalid = 1;
184}
185EXPORT_SYMBOL(set_dma_mode);
186
187
188
189void enable_dma (unsigned int chan)
190{
191 dma_t *dma = dma_channel(chan);
192
193 if (!dma->lock)
194 goto free_dma;
195
196 if (dma->active == 0) {
197 dma->active = 1;
198 dma->d_ops->enable(chan, dma);
199 }
200 return;
201
202free_dma:
203 printk(KERN_ERR "dma%d: trying to enable free DMA\n", chan);
204 BUG();
205}
206EXPORT_SYMBOL(enable_dma);
207
208
209
210void disable_dma (unsigned int chan)
211{
212 dma_t *dma = dma_channel(chan);
213
214 if (!dma->lock)
215 goto free_dma;
216
217 if (dma->active == 1) {
218 dma->active = 0;
219 dma->d_ops->disable(chan, dma);
220 }
221 return;
222
223free_dma:
224 printk(KERN_ERR "dma%d: trying to disable free DMA\n", chan);
225 BUG();
226}
227EXPORT_SYMBOL(disable_dma);
228
229
230
231
232int dma_channel_active(unsigned int chan)
233{
234 dma_t *dma = dma_channel(chan);
235 return dma->active;
236}
237EXPORT_SYMBOL(dma_channel_active);
238
239void set_dma_page(unsigned int chan, char pagenr)
240{
241 printk(KERN_ERR "dma%d: trying to set_dma_page\n", chan);
242}
243EXPORT_SYMBOL(set_dma_page);
244
245void set_dma_speed(unsigned int chan, int cycle_ns)
246{
247 dma_t *dma = dma_channel(chan);
248 int ret = 0;
249
250 if (dma->d_ops->setspeed)
251 ret = dma->d_ops->setspeed(chan, dma, cycle_ns);
252 dma->speed = ret;
253}
254EXPORT_SYMBOL(set_dma_speed);
255
256int get_dma_residue(unsigned int chan)
257{
258 dma_t *dma = dma_channel(chan);
259 int ret = 0;
260
261 if (dma->d_ops->residue)
262 ret = dma->d_ops->residue(chan, dma);
263
264 return ret;
265}
266EXPORT_SYMBOL(get_dma_residue);
267