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Linux/sound/soc/sh/dma-sh7760.c

  1 /*
  2  * SH7760 ("camelot") DMABRG audio DMA unit support
  3  *
  4  * Copyright (C) 2007 Manuel Lauss <mano@roarinelk.homelinux.net>
  5  *  licensed under the terms outlined in the file COPYING at the root
  6  *  of the linux kernel sources.
  7  *
  8  * The SH7760 DMABRG provides 4 dma channels (2x rec, 2x play), which
  9  * trigger an interrupt when one half of the programmed transfer size
 10  * has been xmitted.
 11  *
 12  * FIXME: little-endian only for now
 13  */
 14 
 15 #include <linux/module.h>
 16 #include <linux/gfp.h>
 17 #include <linux/init.h>
 18 #include <linux/platform_device.h>
 19 #include <linux/dma-mapping.h>
 20 #include <sound/core.h>
 21 #include <sound/pcm.h>
 22 #include <sound/pcm_params.h>
 23 #include <sound/soc.h>
 24 #include <asm/dmabrg.h>
 25 
 26 
 27 /* registers and bits */
 28 #define BRGATXSAR       0x00
 29 #define BRGARXDAR       0x04
 30 #define BRGATXTCR       0x08
 31 #define BRGARXTCR       0x0C
 32 #define BRGACR          0x10
 33 #define BRGATXTCNT      0x14
 34 #define BRGARXTCNT      0x18
 35 
 36 #define ACR_RAR         (1 << 18)
 37 #define ACR_RDS         (1 << 17)
 38 #define ACR_RDE         (1 << 16)
 39 #define ACR_TAR         (1 << 2)
 40 #define ACR_TDS         (1 << 1)
 41 #define ACR_TDE         (1 << 0)
 42 
 43 /* receiver/transmitter data alignment */
 44 #define ACR_RAM_NONE    (0 << 24)
 45 #define ACR_RAM_4BYTE   (1 << 24)
 46 #define ACR_RAM_2WORD   (2 << 24)
 47 #define ACR_TAM_NONE    (0 << 8)
 48 #define ACR_TAM_4BYTE   (1 << 8)
 49 #define ACR_TAM_2WORD   (2 << 8)
 50 
 51 
 52 struct camelot_pcm {
 53         unsigned long mmio;  /* DMABRG audio channel control reg MMIO */
 54         unsigned int txid;    /* ID of first DMABRG IRQ for this unit */
 55 
 56         struct snd_pcm_substream *tx_ss;
 57         unsigned long tx_period_size;
 58         unsigned int  tx_period;
 59 
 60         struct snd_pcm_substream *rx_ss;
 61         unsigned long rx_period_size;
 62         unsigned int  rx_period;
 63 
 64 } cam_pcm_data[2] = {
 65         {
 66                 .mmio   =       0xFE3C0040,
 67                 .txid   =       DMABRGIRQ_A0TXF,
 68         },
 69         {
 70                 .mmio   =       0xFE3C0060,
 71                 .txid   =       DMABRGIRQ_A1TXF,
 72         },
 73 };
 74 
 75 #define BRGREG(x)       (*(unsigned long *)(cam->mmio + (x)))
 76 
 77 /*
 78  * set a minimum of 16kb per period, to avoid interrupt-"storm" and
 79  * resulting skipping. In general, the bigger the minimum size, the
 80  * better for overall system performance. (The SH7760 is a puny CPU
 81  * with a slow SDRAM interface and poor internal bus bandwidth,
 82  * *especially* when the LCDC is active).  The minimum for the DMAC
 83  * is 8 bytes; 16kbytes are enough to get skip-free playback of a
 84  * 44kHz/16bit/stereo MP3 on a lightly loaded system, and maintain
 85  * reasonable responsiveness in MPlayer.
 86  */
 87 #define DMABRG_PERIOD_MIN               16 * 1024
 88 #define DMABRG_PERIOD_MAX               0x03fffffc
 89 #define DMABRG_PREALLOC_BUFFER          32 * 1024
 90 #define DMABRG_PREALLOC_BUFFER_MAX      32 * 1024
 91 
 92 static struct snd_pcm_hardware camelot_pcm_hardware = {
 93         .info = (SNDRV_PCM_INFO_MMAP |
 94                 SNDRV_PCM_INFO_INTERLEAVED |
 95                 SNDRV_PCM_INFO_BLOCK_TRANSFER |
 96                 SNDRV_PCM_INFO_MMAP_VALID |
 97                 SNDRV_PCM_INFO_BATCH),
 98         .buffer_bytes_max =     DMABRG_PERIOD_MAX,
 99         .period_bytes_min =     DMABRG_PERIOD_MIN,
100         .period_bytes_max =     DMABRG_PERIOD_MAX / 2,
101         .periods_min =          2,
102         .periods_max =          2,
103         .fifo_size =            128,
104 };
105 
106 static void camelot_txdma(void *data)
107 {
108         struct camelot_pcm *cam = data;
109         cam->tx_period ^= 1;
110         snd_pcm_period_elapsed(cam->tx_ss);
111 }
112 
113 static void camelot_rxdma(void *data)
114 {
115         struct camelot_pcm *cam = data;
116         cam->rx_period ^= 1;
117         snd_pcm_period_elapsed(cam->rx_ss);
118 }
119 
120 static int camelot_pcm_open(struct snd_pcm_substream *substream)
121 {
122         struct snd_soc_pcm_runtime *rtd = substream->private_data;
123         struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id];
124         int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1;
125         int ret, dmairq;
126 
127         snd_soc_set_runtime_hwparams(substream, &camelot_pcm_hardware);
128 
129         /* DMABRG buffer half/full events */
130         dmairq = (recv) ? cam->txid + 2 : cam->txid;
131         if (recv) {
132                 cam->rx_ss = substream;
133                 ret = dmabrg_request_irq(dmairq, camelot_rxdma, cam);
134                 if (unlikely(ret)) {
135                         pr_debug("audio unit %d irqs already taken!\n",
136                              rtd->cpu_dai->id);
137                         return -EBUSY;
138                 }
139                 (void)dmabrg_request_irq(dmairq + 1,camelot_rxdma, cam);
140         } else {
141                 cam->tx_ss = substream;
142                 ret = dmabrg_request_irq(dmairq, camelot_txdma, cam);
143                 if (unlikely(ret)) {
144                         pr_debug("audio unit %d irqs already taken!\n",
145                              rtd->cpu_dai->id);
146                         return -EBUSY;
147                 }
148                 (void)dmabrg_request_irq(dmairq + 1, camelot_txdma, cam);
149         }
150         return 0;
151 }
152 
153 static int camelot_pcm_close(struct snd_pcm_substream *substream)
154 {
155         struct snd_soc_pcm_runtime *rtd = substream->private_data;
156         struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id];
157         int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1;
158         int dmairq;
159 
160         dmairq = (recv) ? cam->txid + 2 : cam->txid;
161 
162         if (recv)
163                 cam->rx_ss = NULL;
164         else
165                 cam->tx_ss = NULL;
166 
167         dmabrg_free_irq(dmairq + 1);
168         dmabrg_free_irq(dmairq);
169 
170         return 0;
171 }
172 
173 static int camelot_hw_params(struct snd_pcm_substream *substream,
174                              struct snd_pcm_hw_params *hw_params)
175 {
176         struct snd_soc_pcm_runtime *rtd = substream->private_data;
177         struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id];
178         int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1;
179         int ret;
180 
181         ret = snd_pcm_lib_malloc_pages(substream,
182                                        params_buffer_bytes(hw_params));
183         if (ret < 0)
184                 return ret;
185 
186         if (recv) {
187                 cam->rx_period_size = params_period_bytes(hw_params);
188                 cam->rx_period = 0;
189         } else {
190                 cam->tx_period_size = params_period_bytes(hw_params);
191                 cam->tx_period = 0;
192         }
193         return 0;
194 }
195 
196 static int camelot_hw_free(struct snd_pcm_substream *substream)
197 {
198         return snd_pcm_lib_free_pages(substream);
199 }
200 
201 static int camelot_prepare(struct snd_pcm_substream *substream)
202 {
203         struct snd_pcm_runtime *runtime = substream->runtime;
204         struct snd_soc_pcm_runtime *rtd = substream->private_data;
205         struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id];
206 
207         pr_debug("PCM data: addr 0x%08ulx len %d\n",
208                  (u32)runtime->dma_addr, runtime->dma_bytes);
209  
210         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
211                 BRGREG(BRGATXSAR) = (unsigned long)runtime->dma_area;
212                 BRGREG(BRGATXTCR) = runtime->dma_bytes;
213         } else {
214                 BRGREG(BRGARXDAR) = (unsigned long)runtime->dma_area;
215                 BRGREG(BRGARXTCR) = runtime->dma_bytes;
216         }
217 
218         return 0;
219 }
220 
221 static inline void dmabrg_play_dma_start(struct camelot_pcm *cam)
222 {
223         unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS);
224         /* start DMABRG engine: XFER start, auto-addr-reload */
225         BRGREG(BRGACR) = acr | ACR_TDE | ACR_TAR | ACR_TAM_2WORD;
226 }
227 
228 static inline void dmabrg_play_dma_stop(struct camelot_pcm *cam)
229 {
230         unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS);
231         /* forcibly terminate data transmission */
232         BRGREG(BRGACR) = acr | ACR_TDS;
233 }
234 
235 static inline void dmabrg_rec_dma_start(struct camelot_pcm *cam)
236 {
237         unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS);
238         /* start DMABRG engine: recv start, auto-reload */
239         BRGREG(BRGACR) = acr | ACR_RDE | ACR_RAR | ACR_RAM_2WORD;
240 }
241 
242 static inline void dmabrg_rec_dma_stop(struct camelot_pcm *cam)
243 {
244         unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS);
245         /* forcibly terminate data receiver */
246         BRGREG(BRGACR) = acr | ACR_RDS;
247 }
248 
249 static int camelot_trigger(struct snd_pcm_substream *substream, int cmd)
250 {
251         struct snd_soc_pcm_runtime *rtd = substream->private_data;
252         struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id];
253         int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1;
254 
255         switch (cmd) {
256         case SNDRV_PCM_TRIGGER_START:
257                 if (recv)
258                         dmabrg_rec_dma_start(cam);
259                 else
260                         dmabrg_play_dma_start(cam);
261                 break;
262         case SNDRV_PCM_TRIGGER_STOP:
263                 if (recv)
264                         dmabrg_rec_dma_stop(cam);
265                 else
266                         dmabrg_play_dma_stop(cam);
267                 break;
268         default:
269                 return -EINVAL;
270         }
271 
272         return 0;
273 }
274 
275 static snd_pcm_uframes_t camelot_pos(struct snd_pcm_substream *substream)
276 {
277         struct snd_pcm_runtime *runtime = substream->runtime;
278         struct snd_soc_pcm_runtime *rtd = substream->private_data;
279         struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id];
280         int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1;
281         unsigned long pos;
282 
283         /* cannot use the DMABRG pointer register: under load, by the
284          * time ALSA comes around to read the register, it is already
285          * far ahead (or worse, already done with the fragment) of the
286          * position at the time the IRQ was triggered, which results in
287          * fast-playback sound in my test application (ScummVM)
288          */
289         if (recv)
290                 pos = cam->rx_period ? cam->rx_period_size : 0;
291         else
292                 pos = cam->tx_period ? cam->tx_period_size : 0;
293 
294         return bytes_to_frames(runtime, pos);
295 }
296 
297 static struct snd_pcm_ops camelot_pcm_ops = {
298         .open           = camelot_pcm_open,
299         .close          = camelot_pcm_close,
300         .ioctl          = snd_pcm_lib_ioctl,
301         .hw_params      = camelot_hw_params,
302         .hw_free        = camelot_hw_free,
303         .prepare        = camelot_prepare,
304         .trigger        = camelot_trigger,
305         .pointer        = camelot_pos,
306 };
307 
308 static void camelot_pcm_free(struct snd_pcm *pcm)
309 {
310         snd_pcm_lib_preallocate_free_for_all(pcm);
311 }
312 
313 static int camelot_pcm_new(struct snd_soc_pcm_runtime *rtd)
314 {
315         struct snd_pcm *pcm = rtd->pcm;
316 
317         /* dont use SNDRV_DMA_TYPE_DEV, since it will oops the SH kernel
318          * in MMAP mode (i.e. aplay -M)
319          */
320         snd_pcm_lib_preallocate_pages_for_all(pcm,
321                 SNDRV_DMA_TYPE_CONTINUOUS,
322                 snd_dma_continuous_data(GFP_KERNEL),
323                 DMABRG_PREALLOC_BUFFER, DMABRG_PREALLOC_BUFFER_MAX);
324 
325         return 0;
326 }
327 
328 static struct snd_soc_platform_driver sh7760_soc_platform = {
329         .ops            = &camelot_pcm_ops,
330         .pcm_new        = camelot_pcm_new,
331         .pcm_free       = camelot_pcm_free,
332 };
333 
334 static int sh7760_soc_platform_probe(struct platform_device *pdev)
335 {
336         return snd_soc_register_platform(&pdev->dev, &sh7760_soc_platform);
337 }
338 
339 static int sh7760_soc_platform_remove(struct platform_device *pdev)
340 {
341         snd_soc_unregister_platform(&pdev->dev);
342         return 0;
343 }
344 
345 static struct platform_driver sh7760_pcm_driver = {
346         .driver = {
347                         .name = "sh7760-pcm-audio",
348                         .owner = THIS_MODULE,
349         },
350 
351         .probe = sh7760_soc_platform_probe,
352         .remove = sh7760_soc_platform_remove,
353 };
354 
355 module_platform_driver(sh7760_pcm_driver);
356 
357 MODULE_LICENSE("GPL");
358 MODULE_DESCRIPTION("SH7760 Audio DMA (DMABRG) driver");
359 MODULE_AUTHOR("Manuel Lauss <mano@roarinelk.homelinux.net>");
360 

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