xref: /openbmc/linux/sound/soc/au1x/dbdma2.c (revision d0b73b48)
1 /*
2  * Au12x0/Au1550 PSC ALSA ASoC audio support.
3  *
4  * (c) 2007-2008 MSC Vertriebsges.m.b.H.,
5  *	Manuel Lauss <manuel.lauss@gmail.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  * DMA glue for Au1x-PSC audio.
12  *
13  */
14 
15 
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/platform_device.h>
19 #include <linux/slab.h>
20 #include <linux/dma-mapping.h>
21 
22 #include <sound/core.h>
23 #include <sound/pcm.h>
24 #include <sound/pcm_params.h>
25 #include <sound/soc.h>
26 
27 #include <asm/mach-au1x00/au1000.h>
28 #include <asm/mach-au1x00/au1xxx_dbdma.h>
29 #include <asm/mach-au1x00/au1xxx_psc.h>
30 
31 #include "psc.h"
32 
33 /*#define PCM_DEBUG*/
34 
35 #define MSG(x...)	printk(KERN_INFO "au1xpsc_pcm: " x)
36 #ifdef PCM_DEBUG
37 #define DBG		MSG
38 #else
39 #define DBG(x...)	do {} while (0)
40 #endif
41 
42 struct au1xpsc_audio_dmadata {
43 	/* DDMA control data */
44 	unsigned int ddma_id;		/* DDMA direction ID for this PSC */
45 	u32 ddma_chan;			/* DDMA context */
46 
47 	/* PCM context (for irq handlers) */
48 	struct snd_pcm_substream *substream;
49 	unsigned long curr_period;	/* current segment DDMA is working on */
50 	unsigned long q_period;		/* queue period(s) */
51 	dma_addr_t dma_area;		/* address of queued DMA area */
52 	dma_addr_t dma_area_s;		/* start address of DMA area */
53 	unsigned long pos;		/* current byte position being played */
54 	unsigned long periods;		/* number of SG segments in total */
55 	unsigned long period_bytes;	/* size in bytes of one SG segment */
56 
57 	/* runtime data */
58 	int msbits;
59 };
60 
61 /*
62  * These settings are somewhat okay, at least on my machine audio plays
63  * almost skip-free. Especially the 64kB buffer seems to help a LOT.
64  */
65 #define AU1XPSC_PERIOD_MIN_BYTES	1024
66 #define AU1XPSC_BUFFER_MIN_BYTES	65536
67 
68 #define AU1XPSC_PCM_FMTS					\
69 	(SNDRV_PCM_FMTBIT_S8     | SNDRV_PCM_FMTBIT_U8 |	\
70 	 SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |	\
71 	 SNDRV_PCM_FMTBIT_U16_LE | SNDRV_PCM_FMTBIT_U16_BE |	\
72 	 SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE |	\
73 	 SNDRV_PCM_FMTBIT_U32_LE | SNDRV_PCM_FMTBIT_U32_BE |	\
74 	 0)
75 
76 /* PCM hardware DMA capabilities - platform specific */
77 static const struct snd_pcm_hardware au1xpsc_pcm_hardware = {
78 	.info		  = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
79 			    SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BATCH,
80 	.formats	  = AU1XPSC_PCM_FMTS,
81 	.period_bytes_min = AU1XPSC_PERIOD_MIN_BYTES,
82 	.period_bytes_max = 4096 * 1024 - 1,
83 	.periods_min	  = 2,
84 	.periods_max	  = 4096,	/* 2 to as-much-as-you-like */
85 	.buffer_bytes_max = 4096 * 1024 - 1,
86 	.fifo_size	  = 16,		/* fifo entries of AC97/I2S PSC */
87 };
88 
89 static void au1x_pcm_queue_tx(struct au1xpsc_audio_dmadata *cd)
90 {
91 	au1xxx_dbdma_put_source(cd->ddma_chan, cd->dma_area,
92 				cd->period_bytes, DDMA_FLAGS_IE);
93 
94 	/* update next-to-queue period */
95 	++cd->q_period;
96 	cd->dma_area += cd->period_bytes;
97 	if (cd->q_period >= cd->periods) {
98 		cd->q_period = 0;
99 		cd->dma_area = cd->dma_area_s;
100 	}
101 }
102 
103 static void au1x_pcm_queue_rx(struct au1xpsc_audio_dmadata *cd)
104 {
105 	au1xxx_dbdma_put_dest(cd->ddma_chan, cd->dma_area,
106 			      cd->period_bytes, DDMA_FLAGS_IE);
107 
108 	/* update next-to-queue period */
109 	++cd->q_period;
110 	cd->dma_area += cd->period_bytes;
111 	if (cd->q_period >= cd->periods) {
112 		cd->q_period = 0;
113 		cd->dma_area = cd->dma_area_s;
114 	}
115 }
116 
117 static void au1x_pcm_dmatx_cb(int irq, void *dev_id)
118 {
119 	struct au1xpsc_audio_dmadata *cd = dev_id;
120 
121 	cd->pos += cd->period_bytes;
122 	if (++cd->curr_period >= cd->periods) {
123 		cd->pos = 0;
124 		cd->curr_period = 0;
125 	}
126 	snd_pcm_period_elapsed(cd->substream);
127 	au1x_pcm_queue_tx(cd);
128 }
129 
130 static void au1x_pcm_dmarx_cb(int irq, void *dev_id)
131 {
132 	struct au1xpsc_audio_dmadata *cd = dev_id;
133 
134 	cd->pos += cd->period_bytes;
135 	if (++cd->curr_period >= cd->periods) {
136 		cd->pos = 0;
137 		cd->curr_period = 0;
138 	}
139 	snd_pcm_period_elapsed(cd->substream);
140 	au1x_pcm_queue_rx(cd);
141 }
142 
143 static void au1x_pcm_dbdma_free(struct au1xpsc_audio_dmadata *pcd)
144 {
145 	if (pcd->ddma_chan) {
146 		au1xxx_dbdma_stop(pcd->ddma_chan);
147 		au1xxx_dbdma_reset(pcd->ddma_chan);
148 		au1xxx_dbdma_chan_free(pcd->ddma_chan);
149 		pcd->ddma_chan = 0;
150 		pcd->msbits = 0;
151 	}
152 }
153 
154 /* in case of missing DMA ring or changed TX-source / RX-dest bit widths,
155  * allocate (or reallocate) a 2-descriptor DMA ring with bit depth according
156  * to ALSA-supplied sample depth.  This is due to limitations in the dbdma api
157  * (cannot adjust source/dest widths of already allocated descriptor ring).
158  */
159 static int au1x_pcm_dbdma_realloc(struct au1xpsc_audio_dmadata *pcd,
160 				 int stype, int msbits)
161 {
162 	/* DMA only in 8/16/32 bit widths */
163 	if (msbits == 24)
164 		msbits = 32;
165 
166 	/* check current config: correct bits and descriptors allocated? */
167 	if ((pcd->ddma_chan) && (msbits == pcd->msbits))
168 		goto out;	/* all ok! */
169 
170 	au1x_pcm_dbdma_free(pcd);
171 
172 	if (stype == SNDRV_PCM_STREAM_CAPTURE)
173 		pcd->ddma_chan = au1xxx_dbdma_chan_alloc(pcd->ddma_id,
174 					DSCR_CMD0_ALWAYS,
175 					au1x_pcm_dmarx_cb, (void *)pcd);
176 	else
177 		pcd->ddma_chan = au1xxx_dbdma_chan_alloc(DSCR_CMD0_ALWAYS,
178 					pcd->ddma_id,
179 					au1x_pcm_dmatx_cb, (void *)pcd);
180 
181 	if (!pcd->ddma_chan)
182 		return -ENOMEM;
183 
184 	au1xxx_dbdma_set_devwidth(pcd->ddma_chan, msbits);
185 	au1xxx_dbdma_ring_alloc(pcd->ddma_chan, 2);
186 
187 	pcd->msbits = msbits;
188 
189 	au1xxx_dbdma_stop(pcd->ddma_chan);
190 	au1xxx_dbdma_reset(pcd->ddma_chan);
191 
192 out:
193 	return 0;
194 }
195 
196 static inline struct au1xpsc_audio_dmadata *to_dmadata(struct snd_pcm_substream *ss)
197 {
198 	struct snd_soc_pcm_runtime *rtd = ss->private_data;
199 	struct au1xpsc_audio_dmadata *pcd =
200 				snd_soc_platform_get_drvdata(rtd->platform);
201 	return &pcd[ss->stream];
202 }
203 
204 static int au1xpsc_pcm_hw_params(struct snd_pcm_substream *substream,
205 				 struct snd_pcm_hw_params *params)
206 {
207 	struct snd_pcm_runtime *runtime = substream->runtime;
208 	struct au1xpsc_audio_dmadata *pcd;
209 	int stype, ret;
210 
211 	ret = snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
212 	if (ret < 0)
213 		goto out;
214 
215 	stype = substream->stream;
216 	pcd = to_dmadata(substream);
217 
218 	DBG("runtime->dma_area = 0x%08lx dma_addr_t = 0x%08lx dma_size = %d "
219 	    "runtime->min_align %d\n",
220 		(unsigned long)runtime->dma_area,
221 		(unsigned long)runtime->dma_addr, runtime->dma_bytes,
222 		runtime->min_align);
223 
224 	DBG("bits %d  frags %d  frag_bytes %d  is_rx %d\n", params->msbits,
225 		params_periods(params), params_period_bytes(params), stype);
226 
227 	ret = au1x_pcm_dbdma_realloc(pcd, stype, params->msbits);
228 	if (ret) {
229 		MSG("DDMA channel (re)alloc failed!\n");
230 		goto out;
231 	}
232 
233 	pcd->substream = substream;
234 	pcd->period_bytes = params_period_bytes(params);
235 	pcd->periods = params_periods(params);
236 	pcd->dma_area_s = pcd->dma_area = runtime->dma_addr;
237 	pcd->q_period = 0;
238 	pcd->curr_period = 0;
239 	pcd->pos = 0;
240 
241 	ret = 0;
242 out:
243 	return ret;
244 }
245 
246 static int au1xpsc_pcm_hw_free(struct snd_pcm_substream *substream)
247 {
248 	snd_pcm_lib_free_pages(substream);
249 	return 0;
250 }
251 
252 static int au1xpsc_pcm_prepare(struct snd_pcm_substream *substream)
253 {
254 	struct au1xpsc_audio_dmadata *pcd = to_dmadata(substream);
255 
256 	au1xxx_dbdma_reset(pcd->ddma_chan);
257 
258 	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
259 		au1x_pcm_queue_rx(pcd);
260 		au1x_pcm_queue_rx(pcd);
261 	} else {
262 		au1x_pcm_queue_tx(pcd);
263 		au1x_pcm_queue_tx(pcd);
264 	}
265 
266 	return 0;
267 }
268 
269 static int au1xpsc_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
270 {
271 	u32 c = to_dmadata(substream)->ddma_chan;
272 
273 	switch (cmd) {
274 	case SNDRV_PCM_TRIGGER_START:
275 	case SNDRV_PCM_TRIGGER_RESUME:
276 		au1xxx_dbdma_start(c);
277 		break;
278 	case SNDRV_PCM_TRIGGER_STOP:
279 	case SNDRV_PCM_TRIGGER_SUSPEND:
280 		au1xxx_dbdma_stop(c);
281 		break;
282 	default:
283 		return -EINVAL;
284 	}
285 	return 0;
286 }
287 
288 static snd_pcm_uframes_t
289 au1xpsc_pcm_pointer(struct snd_pcm_substream *substream)
290 {
291 	return bytes_to_frames(substream->runtime, to_dmadata(substream)->pos);
292 }
293 
294 static int au1xpsc_pcm_open(struct snd_pcm_substream *substream)
295 {
296 	struct au1xpsc_audio_dmadata *pcd = to_dmadata(substream);
297 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
298 	int stype = substream->stream, *dmaids;
299 
300 	dmaids = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
301 	if (!dmaids)
302 		return -ENODEV;	/* whoa, has ordering changed? */
303 
304 	pcd->ddma_id = dmaids[stype];
305 
306 	snd_soc_set_runtime_hwparams(substream, &au1xpsc_pcm_hardware);
307 	return 0;
308 }
309 
310 static int au1xpsc_pcm_close(struct snd_pcm_substream *substream)
311 {
312 	au1x_pcm_dbdma_free(to_dmadata(substream));
313 	return 0;
314 }
315 
316 static struct snd_pcm_ops au1xpsc_pcm_ops = {
317 	.open		= au1xpsc_pcm_open,
318 	.close		= au1xpsc_pcm_close,
319 	.ioctl		= snd_pcm_lib_ioctl,
320 	.hw_params	= au1xpsc_pcm_hw_params,
321 	.hw_free	= au1xpsc_pcm_hw_free,
322 	.prepare	= au1xpsc_pcm_prepare,
323 	.trigger	= au1xpsc_pcm_trigger,
324 	.pointer	= au1xpsc_pcm_pointer,
325 };
326 
327 static void au1xpsc_pcm_free_dma_buffers(struct snd_pcm *pcm)
328 {
329 	snd_pcm_lib_preallocate_free_for_all(pcm);
330 }
331 
332 static int au1xpsc_pcm_new(struct snd_soc_pcm_runtime *rtd)
333 {
334 	struct snd_card *card = rtd->card->snd_card;
335 	struct snd_pcm *pcm = rtd->pcm;
336 
337 	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
338 		card->dev, AU1XPSC_BUFFER_MIN_BYTES, (4096 * 1024) - 1);
339 
340 	return 0;
341 }
342 
343 /* au1xpsc audio platform */
344 static struct snd_soc_platform_driver au1xpsc_soc_platform = {
345 	.ops		= &au1xpsc_pcm_ops,
346 	.pcm_new	= au1xpsc_pcm_new,
347 	.pcm_free	= au1xpsc_pcm_free_dma_buffers,
348 };
349 
350 static int au1xpsc_pcm_drvprobe(struct platform_device *pdev)
351 {
352 	struct au1xpsc_audio_dmadata *dmadata;
353 
354 	dmadata = devm_kzalloc(&pdev->dev,
355 			       2 * sizeof(struct au1xpsc_audio_dmadata),
356 			       GFP_KERNEL);
357 	if (!dmadata)
358 		return -ENOMEM;
359 
360 	platform_set_drvdata(pdev, dmadata);
361 
362 	return snd_soc_register_platform(&pdev->dev, &au1xpsc_soc_platform);
363 }
364 
365 static int au1xpsc_pcm_drvremove(struct platform_device *pdev)
366 {
367 	snd_soc_unregister_platform(&pdev->dev);
368 
369 	return 0;
370 }
371 
372 static struct platform_driver au1xpsc_pcm_driver = {
373 	.driver	= {
374 		.name	= "au1xpsc-pcm",
375 		.owner	= THIS_MODULE,
376 	},
377 	.probe		= au1xpsc_pcm_drvprobe,
378 	.remove		= au1xpsc_pcm_drvremove,
379 };
380 
381 module_platform_driver(au1xpsc_pcm_driver);
382 
383 MODULE_LICENSE("GPL");
384 MODULE_DESCRIPTION("Au12x0/Au1550 PSC Audio DMA driver");
385 MODULE_AUTHOR("Manuel Lauss");
386