32064fafbc2e548d267c615f47cdd31037850a5a
[linux-2.6.git] / sound / atmel / abdac.c
1 /*
2  * Driver for the Atmel on-chip Audio Bitstream DAC (ABDAC)
3  *
4  * Copyright (C) 2006-2009 Atmel Corporation
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License version 2 as published by
8  * the Free Software Foundation.
9  */
10 #include <linux/clk.h>
11 #include <linux/bitmap.h>
12 #include <linux/dw_dmac.h>
13 #include <linux/dmaengine.h>
14 #include <linux/dma-mapping.h>
15 #include <linux/init.h>
16 #include <linux/interrupt.h>
17 #include <linux/module.h>
18 #include <linux/platform_device.h>
19 #include <linux/io.h>
20
21 #include <sound/core.h>
22 #include <sound/initval.h>
23 #include <sound/pcm.h>
24 #include <sound/pcm_params.h>
25 #include <sound/atmel-abdac.h>
26
27 /* DAC register offsets */
28 #define DAC_DATA                                0x0000
29 #define DAC_CTRL                                0x0008
30 #define DAC_INT_MASK                            0x000c
31 #define DAC_INT_EN                              0x0010
32 #define DAC_INT_DIS                             0x0014
33 #define DAC_INT_CLR                             0x0018
34 #define DAC_INT_STATUS                          0x001c
35
36 /* Bitfields in CTRL */
37 #define DAC_SWAP_OFFSET                         30
38 #define DAC_SWAP_SIZE                           1
39 #define DAC_EN_OFFSET                           31
40 #define DAC_EN_SIZE                             1
41
42 /* Bitfields in INT_MASK/INT_EN/INT_DIS/INT_STATUS/INT_CLR */
43 #define DAC_UNDERRUN_OFFSET                     28
44 #define DAC_UNDERRUN_SIZE                       1
45 #define DAC_TX_READY_OFFSET                     29
46 #define DAC_TX_READY_SIZE                       1
47
48 /* Bit manipulation macros */
49 #define DAC_BIT(name)                                   \
50         (1 << DAC_##name##_OFFSET)
51 #define DAC_BF(name, value)                             \
52         (((value) & ((1 << DAC_##name##_SIZE) - 1))     \
53          << DAC_##name##_OFFSET)
54 #define DAC_BFEXT(name, value)                          \
55         (((value) >> DAC_##name##_OFFSET)               \
56          & ((1 << DAC_##name##_SIZE) - 1))
57 #define DAC_BFINS(name, value, old)                     \
58         (((old) & ~(((1 << DAC_##name##_SIZE) - 1)      \
59                     << DAC_##name##_OFFSET))            \
60          | DAC_BF(name, value))
61
62 /* Register access macros */
63 #define dac_readl(port, reg)                            \
64         __raw_readl((port)->regs + DAC_##reg)
65 #define dac_writel(port, reg, value)                    \
66         __raw_writel((value), (port)->regs + DAC_##reg)
67
68 /*
69  * ABDAC supports a maximum of 6 different rates from a generic clock. The
70  * generic clock has a power of two divider, which gives 6 steps from 192 kHz
71  * to 5112 Hz.
72  */
73 #define MAX_NUM_RATES   6
74 /* ALSA seems to use rates between 192000 Hz and 5112 Hz. */
75 #define RATE_MAX        192000
76 #define RATE_MIN        5112
77
78 enum {
79         DMA_READY = 0,
80 };
81
82 struct atmel_abdac_dma {
83         struct dma_chan         *chan;
84         struct dw_cyclic_desc   *cdesc;
85 };
86
87 struct atmel_abdac {
88         struct clk                              *pclk;
89         struct clk                              *sample_clk;
90         struct platform_device                  *pdev;
91         struct atmel_abdac_dma                  dma;
92
93         struct snd_pcm_hw_constraint_list       constraints_rates;
94         struct snd_pcm_substream                *substream;
95         struct snd_card                         *card;
96         struct snd_pcm                          *pcm;
97
98         void __iomem                            *regs;
99         unsigned long                           flags;
100         unsigned int                            rates[MAX_NUM_RATES];
101         unsigned int                            rates_num;
102         int                                     irq;
103 };
104
105 #define get_dac(card) ((struct atmel_abdac *)(card)->private_data)
106
107 /* This function is called by the DMA driver. */
108 static void atmel_abdac_dma_period_done(void *arg)
109 {
110         struct atmel_abdac *dac = arg;
111         snd_pcm_period_elapsed(dac->substream);
112 }
113
114 static int atmel_abdac_prepare_dma(struct atmel_abdac *dac,
115                 struct snd_pcm_substream *substream,
116                 enum dma_data_direction direction)
117 {
118         struct dma_chan                 *chan = dac->dma.chan;
119         struct dw_cyclic_desc           *cdesc;
120         struct snd_pcm_runtime          *runtime = substream->runtime;
121         unsigned long                   buffer_len, period_len;
122
123         /*
124          * We don't do DMA on "complex" transfers, i.e. with
125          * non-halfword-aligned buffers or lengths.
126          */
127         if (runtime->dma_addr & 1 || runtime->buffer_size & 1) {
128                 dev_dbg(&dac->pdev->dev, "too complex transfer\n");
129                 return -EINVAL;
130         }
131
132         buffer_len = frames_to_bytes(runtime, runtime->buffer_size);
133         period_len = frames_to_bytes(runtime, runtime->period_size);
134
135         cdesc = dw_dma_cyclic_prep(chan, runtime->dma_addr, buffer_len,
136                         period_len, DMA_TO_DEVICE);
137         if (IS_ERR(cdesc)) {
138                 dev_dbg(&dac->pdev->dev, "could not prepare cyclic DMA\n");
139                 return PTR_ERR(cdesc);
140         }
141
142         cdesc->period_callback = atmel_abdac_dma_period_done;
143         cdesc->period_callback_param = dac;
144
145         dac->dma.cdesc = cdesc;
146
147         set_bit(DMA_READY, &dac->flags);
148
149         return 0;
150 }
151
152 static struct snd_pcm_hardware atmel_abdac_hw = {
153         .info                   = (SNDRV_PCM_INFO_MMAP
154                                   | SNDRV_PCM_INFO_MMAP_VALID
155                                   | SNDRV_PCM_INFO_INTERLEAVED
156                                   | SNDRV_PCM_INFO_BLOCK_TRANSFER
157                                   | SNDRV_PCM_INFO_RESUME
158                                   | SNDRV_PCM_INFO_PAUSE),
159         .formats                = (SNDRV_PCM_FMTBIT_S16_BE),
160         .rates                  = (SNDRV_PCM_RATE_KNOT),
161         .rate_min               = RATE_MIN,
162         .rate_max               = RATE_MAX,
163         .channels_min           = 2,
164         .channels_max           = 2,
165         .buffer_bytes_max       = 64 * 4096,
166         .period_bytes_min       = 4096,
167         .period_bytes_max       = 4096,
168         .periods_min            = 4,
169         .periods_max            = 64,
170 };
171
172 static int atmel_abdac_open(struct snd_pcm_substream *substream)
173 {
174         struct atmel_abdac *dac = snd_pcm_substream_chip(substream);
175
176         dac->substream = substream;
177         atmel_abdac_hw.rate_max = dac->rates[dac->rates_num - 1];
178         atmel_abdac_hw.rate_min = dac->rates[0];
179         substream->runtime->hw = atmel_abdac_hw;
180
181         return snd_pcm_hw_constraint_list(substream->runtime, 0,
182                         SNDRV_PCM_HW_PARAM_RATE, &dac->constraints_rates);
183 }
184
185 static int atmel_abdac_close(struct snd_pcm_substream *substream)
186 {
187         struct atmel_abdac *dac = snd_pcm_substream_chip(substream);
188         dac->substream = NULL;
189         return 0;
190 }
191
192 static int atmel_abdac_hw_params(struct snd_pcm_substream *substream,
193                 struct snd_pcm_hw_params *hw_params)
194 {
195         struct atmel_abdac *dac = snd_pcm_substream_chip(substream);
196         int retval;
197
198         retval = snd_pcm_lib_malloc_pages(substream,
199                         params_buffer_bytes(hw_params));
200         if (retval < 0)
201                 return retval;
202         /* snd_pcm_lib_malloc_pages returns 1 if buffer is changed. */
203         if (retval == 1)
204                 if (test_and_clear_bit(DMA_READY, &dac->flags))
205                         dw_dma_cyclic_free(dac->dma.chan);
206
207         return retval;
208 }
209
210 static int atmel_abdac_hw_free(struct snd_pcm_substream *substream)
211 {
212         struct atmel_abdac *dac = snd_pcm_substream_chip(substream);
213         if (test_and_clear_bit(DMA_READY, &dac->flags))
214                 dw_dma_cyclic_free(dac->dma.chan);
215         return snd_pcm_lib_free_pages(substream);
216 }
217
218 static int atmel_abdac_prepare(struct snd_pcm_substream *substream)
219 {
220         struct atmel_abdac *dac = snd_pcm_substream_chip(substream);
221         int retval;
222
223         retval = clk_set_rate(dac->sample_clk, 256 * substream->runtime->rate);
224         if (retval)
225                 return retval;
226
227         if (!test_bit(DMA_READY, &dac->flags))
228                 retval = atmel_abdac_prepare_dma(dac, substream, DMA_TO_DEVICE);
229
230         return retval;
231 }
232
233 static int atmel_abdac_trigger(struct snd_pcm_substream *substream, int cmd)
234 {
235         struct atmel_abdac *dac = snd_pcm_substream_chip(substream);
236         int retval = 0;
237
238         switch (cmd) {
239         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: /* fall through */
240         case SNDRV_PCM_TRIGGER_RESUME: /* fall through */
241         case SNDRV_PCM_TRIGGER_START:
242                 clk_enable(dac->sample_clk);
243                 retval = dw_dma_cyclic_start(dac->dma.chan);
244                 if (retval)
245                         goto out;
246                 dac_writel(dac, CTRL, DAC_BIT(EN));
247                 break;
248         case SNDRV_PCM_TRIGGER_PAUSE_PUSH: /* fall through */
249         case SNDRV_PCM_TRIGGER_SUSPEND: /* fall through */
250         case SNDRV_PCM_TRIGGER_STOP:
251                 dw_dma_cyclic_stop(dac->dma.chan);
252                 dac_writel(dac, DATA, 0);
253                 dac_writel(dac, CTRL, 0);
254                 clk_disable(dac->sample_clk);
255                 break;
256         default:
257                 retval = -EINVAL;
258                 break;
259         }
260 out:
261         return retval;
262 }
263
264 static snd_pcm_uframes_t
265 atmel_abdac_pointer(struct snd_pcm_substream *substream)
266 {
267         struct atmel_abdac      *dac = snd_pcm_substream_chip(substream);
268         struct snd_pcm_runtime  *runtime = substream->runtime;
269         snd_pcm_uframes_t       frames;
270         unsigned long           bytes;
271
272         bytes = dw_dma_get_src_addr(dac->dma.chan);
273         bytes -= runtime->dma_addr;
274
275         frames = bytes_to_frames(runtime, bytes);
276         if (frames >= runtime->buffer_size)
277                 frames -= runtime->buffer_size;
278
279         return frames;
280 }
281
282 static irqreturn_t abdac_interrupt(int irq, void *dev_id)
283 {
284         struct atmel_abdac *dac = dev_id;
285         u32 status;
286
287         status = dac_readl(dac, INT_STATUS);
288         if (status & DAC_BIT(UNDERRUN)) {
289                 dev_err(&dac->pdev->dev, "underrun detected\n");
290                 dac_writel(dac, INT_CLR, DAC_BIT(UNDERRUN));
291         } else {
292                 dev_err(&dac->pdev->dev, "spurious interrupt (status=0x%x)\n",
293                         status);
294                 dac_writel(dac, INT_CLR, status);
295         }
296
297         return IRQ_HANDLED;
298 }
299
300 static struct snd_pcm_ops atmel_abdac_ops = {
301         .open           = atmel_abdac_open,
302         .close          = atmel_abdac_close,
303         .ioctl          = snd_pcm_lib_ioctl,
304         .hw_params      = atmel_abdac_hw_params,
305         .hw_free        = atmel_abdac_hw_free,
306         .prepare        = atmel_abdac_prepare,
307         .trigger        = atmel_abdac_trigger,
308         .pointer        = atmel_abdac_pointer,
309 };
310
311 static int __devinit atmel_abdac_pcm_new(struct atmel_abdac *dac)
312 {
313         struct snd_pcm_hardware hw = atmel_abdac_hw;
314         struct snd_pcm *pcm;
315         int retval;
316
317         retval = snd_pcm_new(dac->card, dac->card->shortname,
318                         dac->pdev->id, 1, 0, &pcm);
319         if (retval)
320                 return retval;
321
322         strcpy(pcm->name, dac->card->shortname);
323         pcm->private_data = dac;
324         pcm->info_flags = 0;
325         dac->pcm = pcm;
326
327         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &atmel_abdac_ops);
328
329         retval = snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
330                         &dac->pdev->dev, hw.periods_min * hw.period_bytes_min,
331                         hw.buffer_bytes_max);
332
333         return retval;
334 }
335
336 static bool filter(struct dma_chan *chan, void *slave)
337 {
338         struct dw_dma_slave *dws = slave;
339
340         if (dws->dma_dev == chan->device->dev) {
341                 chan->private = dws;
342                 return true;
343         } else
344                 return false;
345 }
346
347 static int set_sample_rates(struct atmel_abdac *dac)
348 {
349         long new_rate = RATE_MAX;
350         int retval = -EINVAL;
351         int index = 0;
352
353         /* we start at 192 kHz and work our way down to 5112 Hz */
354         while (new_rate >= RATE_MIN && index < (MAX_NUM_RATES + 1)) {
355                 new_rate = clk_round_rate(dac->sample_clk, 256 * new_rate);
356                 if (new_rate < 0)
357                         break;
358                 /* make sure we are below the ABDAC clock */
359                 if (new_rate <= clk_get_rate(dac->pclk)) {
360                         dac->rates[index] = new_rate / 256;
361                         index++;
362                 }
363                 /* divide by 256 and then by two to get next rate */
364                 new_rate /= 256 * 2;
365         }
366
367         if (index) {
368                 int i;
369
370                 /* reverse array, smallest go first */
371                 for (i = 0; i < (index / 2); i++) {
372                         unsigned int tmp = dac->rates[index - 1 - i];
373                         dac->rates[index - 1 - i] = dac->rates[i];
374                         dac->rates[i] = tmp;
375                 }
376
377                 dac->constraints_rates.count = index;
378                 dac->constraints_rates.list = dac->rates;
379                 dac->constraints_rates.mask = 0;
380                 dac->rates_num = index;
381
382                 retval = 0;
383         }
384
385         return retval;
386 }
387
388 static int __devinit atmel_abdac_probe(struct platform_device *pdev)
389 {
390         struct snd_card         *card;
391         struct atmel_abdac      *dac;
392         struct resource         *regs;
393         struct atmel_abdac_pdata        *pdata;
394         struct clk              *pclk;
395         struct clk              *sample_clk;
396         int                     retval;
397         int                     irq;
398
399         regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
400         if (!regs) {
401                 dev_dbg(&pdev->dev, "no memory resource\n");
402                 return -ENXIO;
403         }
404
405         irq = platform_get_irq(pdev, 0);
406         if (irq < 0) {
407                 dev_dbg(&pdev->dev, "could not get IRQ number\n");
408                 return irq;
409         }
410
411         pdata = pdev->dev.platform_data;
412         if (!pdata) {
413                 dev_dbg(&pdev->dev, "no platform data\n");
414                 return -ENXIO;
415         }
416
417         pclk = clk_get(&pdev->dev, "pclk");
418         if (IS_ERR(pclk)) {
419                 dev_dbg(&pdev->dev, "no peripheral clock\n");
420                 return PTR_ERR(pclk);
421         }
422         sample_clk = clk_get(&pdev->dev, "sample_clk");
423         if (IS_ERR(pclk)) {
424                 dev_dbg(&pdev->dev, "no sample clock\n");
425                 retval = PTR_ERR(pclk);
426                 goto out_put_pclk;
427         }
428         clk_enable(pclk);
429
430         retval = snd_card_create(SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1,
431                         THIS_MODULE, sizeof(struct atmel_abdac), &card);
432         if (retval) {
433                 dev_dbg(&pdev->dev, "could not create sound card device\n");
434                 goto out_put_sample_clk;
435         }
436
437         dac = get_dac(card);
438
439         dac->irq = irq;
440         dac->card = card;
441         dac->pclk = pclk;
442         dac->sample_clk = sample_clk;
443         dac->pdev = pdev;
444
445         retval = set_sample_rates(dac);
446         if (retval < 0) {
447                 dev_dbg(&pdev->dev, "could not set supported rates\n");
448                 goto out_free_card;
449         }
450
451         dac->regs = ioremap(regs->start, regs->end - regs->start + 1);
452         if (!dac->regs) {
453                 dev_dbg(&pdev->dev, "could not remap register memory\n");
454                 goto out_free_card;
455         }
456
457         /* make sure the DAC is silent and disabled */
458         dac_writel(dac, DATA, 0);
459         dac_writel(dac, CTRL, 0);
460
461         retval = request_irq(irq, abdac_interrupt, 0, "abdac", dac);
462         if (retval) {
463                 dev_dbg(&pdev->dev, "could not request irq\n");
464                 goto out_unmap_regs;
465         }
466
467         snd_card_set_dev(card, &pdev->dev);
468
469         if (pdata->dws.dma_dev) {
470                 struct dw_dma_slave *dws = &pdata->dws;
471                 dma_cap_mask_t mask;
472
473                 dws->tx_reg = regs->start + DAC_DATA;
474
475                 dma_cap_zero(mask);
476                 dma_cap_set(DMA_SLAVE, mask);
477
478                 dac->dma.chan = dma_request_channel(mask, filter, dws);
479         }
480         if (!pdata->dws.dma_dev || !dac->dma.chan) {
481                 dev_dbg(&pdev->dev, "DMA not available\n");
482                 retval = -ENODEV;
483                 goto out_unset_card_dev;
484         }
485
486         strcpy(card->driver, "Atmel ABDAC");
487         strcpy(card->shortname, "Atmel ABDAC");
488         sprintf(card->longname, "Atmel Audio Bitstream DAC");
489
490         retval = atmel_abdac_pcm_new(dac);
491         if (retval) {
492                 dev_dbg(&pdev->dev, "could not register ABDAC pcm device\n");
493                 goto out_release_dma;
494         }
495
496         retval = snd_card_register(card);
497         if (retval) {
498                 dev_dbg(&pdev->dev, "could not register sound card\n");
499                 goto out_release_dma;
500         }
501
502         platform_set_drvdata(pdev, card);
503
504         dev_info(&pdev->dev, "Atmel ABDAC at 0x%p using %s\n",
505                         dac->regs, dev_name(&dac->dma.chan->dev->device));
506
507         return retval;
508
509 out_release_dma:
510         dma_release_channel(dac->dma.chan);
511         dac->dma.chan = NULL;
512 out_unset_card_dev:
513         snd_card_set_dev(card, NULL);
514         free_irq(irq, dac);
515 out_unmap_regs:
516         iounmap(dac->regs);
517 out_free_card:
518         snd_card_free(card);
519 out_put_sample_clk:
520         clk_put(sample_clk);
521         clk_disable(pclk);
522 out_put_pclk:
523         clk_put(pclk);
524         return retval;
525 }
526
527 #ifdef CONFIG_PM
528 static int atmel_abdac_suspend(struct platform_device *pdev, pm_message_t msg)
529 {
530         struct snd_card *card = platform_get_drvdata(pdev);
531         struct atmel_abdac *dac = card->private_data;
532
533         dw_dma_cyclic_stop(dac->dma.chan);
534         clk_disable(dac->sample_clk);
535         clk_disable(dac->pclk);
536
537         return 0;
538 }
539
540 static int atmel_abdac_resume(struct platform_device *pdev)
541 {
542         struct snd_card *card = platform_get_drvdata(pdev);
543         struct atmel_abdac *dac = card->private_data;
544
545         clk_enable(dac->pclk);
546         clk_enable(dac->sample_clk);
547         if (test_bit(DMA_READY, &dac->flags))
548                 dw_dma_cyclic_start(dac->dma.chan);
549
550         return 0;
551 }
552 #else
553 #define atmel_abdac_suspend NULL
554 #define atmel_abdac_resume NULL
555 #endif
556
557 static int __devexit atmel_abdac_remove(struct platform_device *pdev)
558 {
559         struct snd_card *card = platform_get_drvdata(pdev);
560         struct atmel_abdac *dac = get_dac(card);
561
562         clk_put(dac->sample_clk);
563         clk_disable(dac->pclk);
564         clk_put(dac->pclk);
565
566         dma_release_channel(dac->dma.chan);
567         dac->dma.chan = NULL;
568         snd_card_set_dev(card, NULL);
569         iounmap(dac->regs);
570         free_irq(dac->irq, dac);
571         snd_card_free(card);
572
573         platform_set_drvdata(pdev, NULL);
574
575         return 0;
576 }
577
578 static struct platform_driver atmel_abdac_driver = {
579         .remove         = __devexit_p(atmel_abdac_remove),
580         .driver         = {
581                 .name   = "atmel_abdac",
582         },
583         .suspend        = atmel_abdac_suspend,
584         .resume         = atmel_abdac_resume,
585 };
586
587 static int __init atmel_abdac_init(void)
588 {
589         return platform_driver_probe(&atmel_abdac_driver,
590                         atmel_abdac_probe);
591 }
592 module_init(atmel_abdac_init);
593
594 static void __exit atmel_abdac_exit(void)
595 {
596         platform_driver_unregister(&atmel_abdac_driver);
597 }
598 module_exit(atmel_abdac_exit);
599
600 MODULE_LICENSE("GPL");
601 MODULE_DESCRIPTION("Driver for Atmel Audio Bitstream DAC (ABDAC)");
602 MODULE_AUTHOR("Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>");