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Linux 3.3.2
[zen-stable.git] / arch / arm / mach-rpc / dma.c
blob85883b2e0e49cdecb8eed50a3042842972de5a81
1 /*
2 * linux/arch/arm/mach-rpc/dma.c
3 *
4 * Copyright (C) 1998 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * DMA functions specific to RiscPC architecture
11 */
12 #include <linux/mman.h>
13 #include <linux/init.h>
14 #include <linux/interrupt.h>
15 #include <linux/dma-mapping.h>
16 #include <linux/io.h>
17
18 #include <asm/page.h>
19 #include <asm/dma.h>
20 #include <asm/fiq.h>
21 #include <asm/irq.h>
22 #include <mach/hardware.h>
23 #include <asm/uaccess.h>
24
25 #include <asm/mach/dma.h>
26 #include <asm/hardware/iomd.h>
27
28 struct iomd_dma {
29 struct dma_struct dma;
30 unsigned int state;
31 unsigned long base; /* Controller base address */
32 int irq; /* Controller IRQ */
33 struct scatterlist cur_sg; /* Current controller buffer */
34 dma_addr_t dma_addr;
35 unsigned int dma_len;
36 };
37
38 #if 0
39 typedef enum {
40 dma_size_8 = 1,
41 dma_size_16 = 2,
42 dma_size_32 = 4,
43 dma_size_128 = 16
44 } dma_size_t;
45 #endif
46
47 #define TRANSFER_SIZE 2
48
49 #define CURA (0)
50 #define ENDA (IOMD_IO0ENDA - IOMD_IO0CURA)
51 #define CURB (IOMD_IO0CURB - IOMD_IO0CURA)
52 #define ENDB (IOMD_IO0ENDB - IOMD_IO0CURA)
53 #define CR (IOMD_IO0CR - IOMD_IO0CURA)
54 #define ST (IOMD_IO0ST - IOMD_IO0CURA)
55
56 static void iomd_get_next_sg(struct scatterlist *sg, struct iomd_dma *idma)
57 {
58 unsigned long end, offset, flags = 0;
59
60 if (idma->dma.sg) {
61 sg->dma_address = idma->dma_addr;
62 offset = sg->dma_address & ~PAGE_MASK;
63
64 end = offset + idma->dma_len;
65
66 if (end > PAGE_SIZE)
67 end = PAGE_SIZE;
68
69 if (offset + TRANSFER_SIZE >= end)
70 flags |= DMA_END_L;
71
72 sg->length = end - TRANSFER_SIZE;
73
74 idma->dma_len -= end - offset;
75 idma->dma_addr += end - offset;
76
77 if (idma->dma_len == 0) {
78 if (idma->dma.sgcount > 1) {
79 idma->dma.sg = sg_next(idma->dma.sg);
80 idma->dma_addr = idma->dma.sg->dma_address;
81 idma->dma_len = idma->dma.sg->length;
82 idma->dma.sgcount--;
83 } else {
84 idma->dma.sg = NULL;
85 flags |= DMA_END_S;
86 }
87 }
88 } else {
89 flags = DMA_END_S | DMA_END_L;
90 sg->dma_address = 0;
91 sg->length = 0;
92 }
93
94 sg->length |= flags;
95 }
96
97 static irqreturn_t iomd_dma_handle(int irq, void *dev_id)
98 {
99 struct iomd_dma *idma = dev_id;
100 unsigned long base = idma->base;
101
102 do {
103 unsigned int status;
104
105 status = iomd_readb(base + ST);
106 if (!(status & DMA_ST_INT))
107 return IRQ_HANDLED;
108
109 if ((idma->state ^ status) & DMA_ST_AB)
110 iomd_get_next_sg(&idma->cur_sg, idma);
111
112 switch (status & (DMA_ST_OFL | DMA_ST_AB)) {
113 case DMA_ST_OFL: /* OIA */
114 case DMA_ST_AB: /* .IB */
115 iomd_writel(idma->cur_sg.dma_address, base + CURA);
116 iomd_writel(idma->cur_sg.length, base + ENDA);
117 idma->state = DMA_ST_AB;
118 break;
119
120 case DMA_ST_OFL | DMA_ST_AB: /* OIB */
121 case 0: /* .IA */
122 iomd_writel(idma->cur_sg.dma_address, base + CURB);
123 iomd_writel(idma->cur_sg.length, base + ENDB);
124 idma->state = 0;
125 break;
126 }
127
128 if (status & DMA_ST_OFL &&
129 idma->cur_sg.length == (DMA_END_S|DMA_END_L))
130 break;
131 } while (1);
132
133 idma->state = ~DMA_ST_AB;
134 disable_irq(irq);
135
136 return IRQ_HANDLED;
137 }
138
139 static int iomd_request_dma(unsigned int chan, dma_t *dma)
140 {
141 struct iomd_dma *idma = container_of(dma, struct iomd_dma, dma);
142
143 return request_irq(idma->irq, iomd_dma_handle,
144 IRQF_DISABLED, idma->dma.device_id, idma);
145 }
146
147 static void iomd_free_dma(unsigned int chan, dma_t *dma)
148 {
149 struct iomd_dma *idma = container_of(dma, struct iomd_dma, dma);
150
151 free_irq(idma->irq, idma);
152 }
153
154 static void iomd_enable_dma(unsigned int chan, dma_t *dma)
155 {
156 struct iomd_dma *idma = container_of(dma, struct iomd_dma, dma);
157 unsigned long dma_base = idma->base;
158 unsigned int ctrl = TRANSFER_SIZE | DMA_CR_E;
159
160 if (idma->dma.invalid) {
161 idma->dma.invalid = 0;
162
163 /*
164 * Cope with ISA-style drivers which expect cache
165 * coherence.
166 */
167 if (!idma->dma.sg) {
168 idma->dma.sg = &idma->dma.buf;
169 idma->dma.sgcount = 1;
170 idma->dma.buf.length = idma->dma.count;
171 idma->dma.buf.dma_address = dma_map_single(NULL,
172 idma->dma.addr, idma->dma.count,
173 idma->dma.dma_mode == DMA_MODE_READ ?
174 DMA_FROM_DEVICE : DMA_TO_DEVICE);
175 }
176
177 iomd_writeb(DMA_CR_C, dma_base + CR);
178 idma->state = DMA_ST_AB;
179 }
180
181 if (idma->dma.dma_mode == DMA_MODE_READ)
182 ctrl |= DMA_CR_D;
183
184 iomd_writeb(ctrl, dma_base + CR);
185 enable_irq(idma->irq);
186 }
187
188 static void iomd_disable_dma(unsigned int chan, dma_t *dma)
189 {
190 struct iomd_dma *idma = container_of(dma, struct iomd_dma, dma);
191 unsigned long dma_base = idma->base;
192 unsigned long flags;
193
194 local_irq_save(flags);
195 if (idma->state != ~DMA_ST_AB)
196 disable_irq(idma->irq);
197 iomd_writeb(0, dma_base + CR);
198 local_irq_restore(flags);
199 }
200
201 static int iomd_set_dma_speed(unsigned int chan, dma_t *dma, int cycle)
202 {
203 int tcr, speed;
204
205 if (cycle < 188)
206 speed = 3;
207 else if (cycle <= 250)
208 speed = 2;
209 else if (cycle < 438)
210 speed = 1;
211 else
212 speed = 0;
213
214 tcr = iomd_readb(IOMD_DMATCR);
215 speed &= 3;
216
217 switch (chan) {
218 case DMA_0:
219 tcr = (tcr & ~0x03) | speed;
220 break;
221
222 case DMA_1:
223 tcr = (tcr & ~0x0c) | (speed << 2);
224 break;
225
226 case DMA_2:
227 tcr = (tcr & ~0x30) | (speed << 4);
228 break;
229
230 case DMA_3:
231 tcr = (tcr & ~0xc0) | (speed << 6);
232 break;
233
234 default:
235 break;
236 }
237
238 iomd_writeb(tcr, IOMD_DMATCR);
239
240 return speed;
241 }
242
243 static struct dma_ops iomd_dma_ops = {
244 .type = "IOMD",
245 .request = iomd_request_dma,
246 .free = iomd_free_dma,
247 .enable = iomd_enable_dma,
248 .disable = iomd_disable_dma,
249 .setspeed = iomd_set_dma_speed,
250 };
251
252 static struct fiq_handler fh = {
253 .name = "floppydma"
254 };
255
256 struct floppy_dma {
257 struct dma_struct dma;
258 unsigned int fiq;
259 };
260
261 static void floppy_enable_dma(unsigned int chan, dma_t *dma)
262 {
263 struct floppy_dma *fdma = container_of(dma, struct floppy_dma, dma);
264 void *fiqhandler_start;
265 unsigned int fiqhandler_length;
266 struct pt_regs regs;
267
268 if (fdma->dma.sg)
269 BUG();
270
271 if (fdma->dma.dma_mode == DMA_MODE_READ) {
272 extern unsigned char floppy_fiqin_start, floppy_fiqin_end;
273 fiqhandler_start = &floppy_fiqin_start;
274 fiqhandler_length = &floppy_fiqin_end - &floppy_fiqin_start;
275 } else {
276 extern unsigned char floppy_fiqout_start, floppy_fiqout_end;
277 fiqhandler_start = &floppy_fiqout_start;
278 fiqhandler_length = &floppy_fiqout_end - &floppy_fiqout_start;
279 }
280
281 regs.ARM_r9 = fdma->dma.count;
282 regs.ARM_r10 = (unsigned long)fdma->dma.addr;
283 regs.ARM_fp = (unsigned long)FLOPPYDMA_BASE;
284
285 if (claim_fiq(&fh)) {
286 printk("floppydma: couldn't claim FIQ.\n");
287 return;
288 }
289
290 set_fiq_handler(fiqhandler_start, fiqhandler_length);
291 set_fiq_regs(&regs);
292 enable_fiq(fdma->fiq);
293 }
294
295 static void floppy_disable_dma(unsigned int chan, dma_t *dma)
296 {
297 struct floppy_dma *fdma = container_of(dma, struct floppy_dma, dma);
298 disable_fiq(fdma->fiq);
299 release_fiq(&fh);
300 }
301
302 static int floppy_get_residue(unsigned int chan, dma_t *dma)
303 {
304 struct pt_regs regs;
305 get_fiq_regs(&regs);
306 return regs.ARM_r9;
307 }
308
309 static struct dma_ops floppy_dma_ops = {
310 .type = "FIQDMA",
311 .enable = floppy_enable_dma,
312 .disable = floppy_disable_dma,
313 .residue = floppy_get_residue,
314 };
315
316 /*
317 * This is virtual DMA - we don't need anything here.
318 */
319 static void sound_enable_disable_dma(unsigned int chan, dma_t *dma)
320 {
321 }
322
323 static struct dma_ops sound_dma_ops = {
324 .type = "VIRTUAL",
325 .enable = sound_enable_disable_dma,
326 .disable = sound_enable_disable_dma,
327 };
328
329 static struct iomd_dma iomd_dma[6];
330
331 static struct floppy_dma floppy_dma = {
332 .dma = {
333 .d_ops = &floppy_dma_ops,
334 },
335 .fiq = FIQ_FLOPPYDATA,
336 };
337
338 static dma_t sound_dma = {
339 .d_ops = &sound_dma_ops,
340 };
341
342 static int __init rpc_dma_init(void)
343 {
344 unsigned int i;
345 int ret;
346
347 iomd_writeb(0, IOMD_IO0CR);
348 iomd_writeb(0, IOMD_IO1CR);
349 iomd_writeb(0, IOMD_IO2CR);
350 iomd_writeb(0, IOMD_IO3CR);
351
352 iomd_writeb(0xa0, IOMD_DMATCR);
353
354 /*
355 * Setup DMA channels 2,3 to be for podules
356 * and channels 0,1 for internal devices
357 */
358 iomd_writeb(DMA_EXT_IO3|DMA_EXT_IO2, IOMD_DMAEXT);
359
360 iomd_dma[DMA_0].base = IOMD_IO0CURA;
361 iomd_dma[DMA_0].irq = IRQ_DMA0;
362 iomd_dma[DMA_1].base = IOMD_IO1CURA;
363 iomd_dma[DMA_1].irq = IRQ_DMA1;
364 iomd_dma[DMA_2].base = IOMD_IO2CURA;
365 iomd_dma[DMA_2].irq = IRQ_DMA2;
366 iomd_dma[DMA_3].base = IOMD_IO3CURA;
367 iomd_dma[DMA_3].irq = IRQ_DMA3;
368 iomd_dma[DMA_S0].base = IOMD_SD0CURA;
369 iomd_dma[DMA_S0].irq = IRQ_DMAS0;
370 iomd_dma[DMA_S1].base = IOMD_SD1CURA;
371 iomd_dma[DMA_S1].irq = IRQ_DMAS1;
372
373 for (i = DMA_0; i <= DMA_S1; i++) {
374 iomd_dma[i].dma.d_ops = &iomd_dma_ops;
375
376 ret = isa_dma_add(i, &iomd_dma[i].dma);
377 if (ret)
378 printk("IOMDDMA%u: unable to register: %d\n", i, ret);
379 }
380
381 ret = isa_dma_add(DMA_VIRTUAL_FLOPPY, &floppy_dma.dma);
382 if (ret)
383 printk("IOMDFLOPPY: unable to register: %d\n", ret);
384 ret = isa_dma_add(DMA_VIRTUAL_SOUND, &sound_dma);
385 if (ret)
386 printk("IOMDSOUND: unable to register: %d\n", ret);
387 return 0;
388 }
389 core_initcall(rpc_dma_init);