xref: /openbmc/linux/sound/soc/au1x/dbdma2.c (revision 93f5715e)
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 DRV_NAME "dbdma2"
36 
37 #define MSG(x...)	printk(KERN_INFO "au1xpsc_pcm: " x)
38 #ifdef PCM_DEBUG
39 #define DBG		MSG
40 #else
41 #define DBG(x...)	do {} while (0)
42 #endif
43 
44 struct au1xpsc_audio_dmadata {
45 	/* DDMA control data */
46 	unsigned int ddma_id;		/* DDMA direction ID for this PSC */
47 	u32 ddma_chan;			/* DDMA context */
48 
49 	/* PCM context (for irq handlers) */
50 	struct snd_pcm_substream *substream;
51 	unsigned long curr_period;	/* current segment DDMA is working on */
52 	unsigned long q_period;		/* queue period(s) */
53 	dma_addr_t dma_area;		/* address of queued DMA area */
54 	dma_addr_t dma_area_s;		/* start address of DMA area */
55 	unsigned long pos;		/* current byte position being played */
56 	unsigned long periods;		/* number of SG segments in total */
57 	unsigned long period_bytes;	/* size in bytes of one SG segment */
58 
59 	/* runtime data */
60 	int msbits;
61 };
62 
63 /*
64  * These settings are somewhat okay, at least on my machine audio plays
65  * almost skip-free. Especially the 64kB buffer seems to help a LOT.
66  */
67 #define AU1XPSC_PERIOD_MIN_BYTES	1024
68 #define AU1XPSC_BUFFER_MIN_BYTES	65536
69 
70 /* PCM hardware DMA capabilities - platform specific */
71 static const struct snd_pcm_hardware au1xpsc_pcm_hardware = {
72 	.info		  = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
73 			    SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BATCH,
74 	.period_bytes_min = AU1XPSC_PERIOD_MIN_BYTES,
75 	.period_bytes_max = 4096 * 1024 - 1,
76 	.periods_min	  = 2,
77 	.periods_max	  = 4096,	/* 2 to as-much-as-you-like */
78 	.buffer_bytes_max = 4096 * 1024 - 1,
79 	.fifo_size	  = 16,		/* fifo entries of AC97/I2S PSC */
80 };
81 
82 static void au1x_pcm_queue_tx(struct au1xpsc_audio_dmadata *cd)
83 {
84 	au1xxx_dbdma_put_source(cd->ddma_chan, cd->dma_area,
85 				cd->period_bytes, DDMA_FLAGS_IE);
86 
87 	/* update next-to-queue period */
88 	++cd->q_period;
89 	cd->dma_area += cd->period_bytes;
90 	if (cd->q_period >= cd->periods) {
91 		cd->q_period = 0;
92 		cd->dma_area = cd->dma_area_s;
93 	}
94 }
95 
96 static void au1x_pcm_queue_rx(struct au1xpsc_audio_dmadata *cd)
97 {
98 	au1xxx_dbdma_put_dest(cd->ddma_chan, cd->dma_area,
99 			      cd->period_bytes, DDMA_FLAGS_IE);
100 
101 	/* update next-to-queue period */
102 	++cd->q_period;
103 	cd->dma_area += cd->period_bytes;
104 	if (cd->q_period >= cd->periods) {
105 		cd->q_period = 0;
106 		cd->dma_area = cd->dma_area_s;
107 	}
108 }
109 
110 static void au1x_pcm_dmatx_cb(int irq, void *dev_id)
111 {
112 	struct au1xpsc_audio_dmadata *cd = dev_id;
113 
114 	cd->pos += cd->period_bytes;
115 	if (++cd->curr_period >= cd->periods) {
116 		cd->pos = 0;
117 		cd->curr_period = 0;
118 	}
119 	snd_pcm_period_elapsed(cd->substream);
120 	au1x_pcm_queue_tx(cd);
121 }
122 
123 static void au1x_pcm_dmarx_cb(int irq, void *dev_id)
124 {
125 	struct au1xpsc_audio_dmadata *cd = dev_id;
126 
127 	cd->pos += cd->period_bytes;
128 	if (++cd->curr_period >= cd->periods) {
129 		cd->pos = 0;
130 		cd->curr_period = 0;
131 	}
132 	snd_pcm_period_elapsed(cd->substream);
133 	au1x_pcm_queue_rx(cd);
134 }
135 
136 static void au1x_pcm_dbdma_free(struct au1xpsc_audio_dmadata *pcd)
137 {
138 	if (pcd->ddma_chan) {
139 		au1xxx_dbdma_stop(pcd->ddma_chan);
140 		au1xxx_dbdma_reset(pcd->ddma_chan);
141 		au1xxx_dbdma_chan_free(pcd->ddma_chan);
142 		pcd->ddma_chan = 0;
143 		pcd->msbits = 0;
144 	}
145 }
146 
147 /* in case of missing DMA ring or changed TX-source / RX-dest bit widths,
148  * allocate (or reallocate) a 2-descriptor DMA ring with bit depth according
149  * to ALSA-supplied sample depth.  This is due to limitations in the dbdma api
150  * (cannot adjust source/dest widths of already allocated descriptor ring).
151  */
152 static int au1x_pcm_dbdma_realloc(struct au1xpsc_audio_dmadata *pcd,
153 				 int stype, int msbits)
154 {
155 	/* DMA only in 8/16/32 bit widths */
156 	if (msbits == 24)
157 		msbits = 32;
158 
159 	/* check current config: correct bits and descriptors allocated? */
160 	if ((pcd->ddma_chan) && (msbits == pcd->msbits))
161 		goto out;	/* all ok! */
162 
163 	au1x_pcm_dbdma_free(pcd);
164 
165 	if (stype == SNDRV_PCM_STREAM_CAPTURE)
166 		pcd->ddma_chan = au1xxx_dbdma_chan_alloc(pcd->ddma_id,
167 					DSCR_CMD0_ALWAYS,
168 					au1x_pcm_dmarx_cb, (void *)pcd);
169 	else
170 		pcd->ddma_chan = au1xxx_dbdma_chan_alloc(DSCR_CMD0_ALWAYS,
171 					pcd->ddma_id,
172 					au1x_pcm_dmatx_cb, (void *)pcd);
173 
174 	if (!pcd->ddma_chan)
175 		return -ENOMEM;
176 
177 	au1xxx_dbdma_set_devwidth(pcd->ddma_chan, msbits);
178 	au1xxx_dbdma_ring_alloc(pcd->ddma_chan, 2);
179 
180 	pcd->msbits = msbits;
181 
182 	au1xxx_dbdma_stop(pcd->ddma_chan);
183 	au1xxx_dbdma_reset(pcd->ddma_chan);
184 
185 out:
186 	return 0;
187 }
188 
189 static inline struct au1xpsc_audio_dmadata *to_dmadata(struct snd_pcm_substream *ss)
190 {
191 	struct snd_soc_pcm_runtime *rtd = ss->private_data;
192 	struct snd_soc_component *component = snd_soc_rtdcom_lookup(rtd, DRV_NAME);
193 	struct au1xpsc_audio_dmadata *pcd = snd_soc_component_get_drvdata(component);
194 	return &pcd[ss->stream];
195 }
196 
197 static int au1xpsc_pcm_hw_params(struct snd_pcm_substream *substream,
198 				 struct snd_pcm_hw_params *params)
199 {
200 	struct snd_pcm_runtime *runtime = substream->runtime;
201 	struct au1xpsc_audio_dmadata *pcd;
202 	int stype, ret;
203 
204 	ret = snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
205 	if (ret < 0)
206 		goto out;
207 
208 	stype = substream->stream;
209 	pcd = to_dmadata(substream);
210 
211 	DBG("runtime->dma_area = 0x%08lx dma_addr_t = 0x%08lx dma_size = %zu "
212 	    "runtime->min_align %lu\n",
213 		(unsigned long)runtime->dma_area,
214 		(unsigned long)runtime->dma_addr, runtime->dma_bytes,
215 		runtime->min_align);
216 
217 	DBG("bits %d  frags %d  frag_bytes %d  is_rx %d\n", params->msbits,
218 		params_periods(params), params_period_bytes(params), stype);
219 
220 	ret = au1x_pcm_dbdma_realloc(pcd, stype, params->msbits);
221 	if (ret) {
222 		MSG("DDMA channel (re)alloc failed!\n");
223 		goto out;
224 	}
225 
226 	pcd->substream = substream;
227 	pcd->period_bytes = params_period_bytes(params);
228 	pcd->periods = params_periods(params);
229 	pcd->dma_area_s = pcd->dma_area = runtime->dma_addr;
230 	pcd->q_period = 0;
231 	pcd->curr_period = 0;
232 	pcd->pos = 0;
233 
234 	ret = 0;
235 out:
236 	return ret;
237 }
238 
239 static int au1xpsc_pcm_hw_free(struct snd_pcm_substream *substream)
240 {
241 	snd_pcm_lib_free_pages(substream);
242 	return 0;
243 }
244 
245 static int au1xpsc_pcm_prepare(struct snd_pcm_substream *substream)
246 {
247 	struct au1xpsc_audio_dmadata *pcd = to_dmadata(substream);
248 
249 	au1xxx_dbdma_reset(pcd->ddma_chan);
250 
251 	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
252 		au1x_pcm_queue_rx(pcd);
253 		au1x_pcm_queue_rx(pcd);
254 	} else {
255 		au1x_pcm_queue_tx(pcd);
256 		au1x_pcm_queue_tx(pcd);
257 	}
258 
259 	return 0;
260 }
261 
262 static int au1xpsc_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
263 {
264 	u32 c = to_dmadata(substream)->ddma_chan;
265 
266 	switch (cmd) {
267 	case SNDRV_PCM_TRIGGER_START:
268 	case SNDRV_PCM_TRIGGER_RESUME:
269 		au1xxx_dbdma_start(c);
270 		break;
271 	case SNDRV_PCM_TRIGGER_STOP:
272 	case SNDRV_PCM_TRIGGER_SUSPEND:
273 		au1xxx_dbdma_stop(c);
274 		break;
275 	default:
276 		return -EINVAL;
277 	}
278 	return 0;
279 }
280 
281 static snd_pcm_uframes_t
282 au1xpsc_pcm_pointer(struct snd_pcm_substream *substream)
283 {
284 	return bytes_to_frames(substream->runtime, to_dmadata(substream)->pos);
285 }
286 
287 static int au1xpsc_pcm_open(struct snd_pcm_substream *substream)
288 {
289 	struct au1xpsc_audio_dmadata *pcd = to_dmadata(substream);
290 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
291 	int stype = substream->stream, *dmaids;
292 
293 	dmaids = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
294 	if (!dmaids)
295 		return -ENODEV;	/* whoa, has ordering changed? */
296 
297 	pcd->ddma_id = dmaids[stype];
298 
299 	snd_soc_set_runtime_hwparams(substream, &au1xpsc_pcm_hardware);
300 	return 0;
301 }
302 
303 static int au1xpsc_pcm_close(struct snd_pcm_substream *substream)
304 {
305 	au1x_pcm_dbdma_free(to_dmadata(substream));
306 	return 0;
307 }
308 
309 static const struct snd_pcm_ops au1xpsc_pcm_ops = {
310 	.open		= au1xpsc_pcm_open,
311 	.close		= au1xpsc_pcm_close,
312 	.ioctl		= snd_pcm_lib_ioctl,
313 	.hw_params	= au1xpsc_pcm_hw_params,
314 	.hw_free	= au1xpsc_pcm_hw_free,
315 	.prepare	= au1xpsc_pcm_prepare,
316 	.trigger	= au1xpsc_pcm_trigger,
317 	.pointer	= au1xpsc_pcm_pointer,
318 };
319 
320 static int au1xpsc_pcm_new(struct snd_soc_pcm_runtime *rtd)
321 {
322 	struct snd_card *card = rtd->card->snd_card;
323 	struct snd_pcm *pcm = rtd->pcm;
324 
325 	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
326 		card->dev, AU1XPSC_BUFFER_MIN_BYTES, (4096 * 1024) - 1);
327 
328 	return 0;
329 }
330 
331 /* au1xpsc audio platform */
332 static struct snd_soc_component_driver au1xpsc_soc_component = {
333 	.name		= DRV_NAME,
334 	.ops		= &au1xpsc_pcm_ops,
335 	.pcm_new	= au1xpsc_pcm_new,
336 };
337 
338 static int au1xpsc_pcm_drvprobe(struct platform_device *pdev)
339 {
340 	struct au1xpsc_audio_dmadata *dmadata;
341 
342 	dmadata = devm_kcalloc(&pdev->dev,
343 			       2, sizeof(struct au1xpsc_audio_dmadata),
344 			       GFP_KERNEL);
345 	if (!dmadata)
346 		return -ENOMEM;
347 
348 	platform_set_drvdata(pdev, dmadata);
349 
350 	return devm_snd_soc_register_component(&pdev->dev,
351 					&au1xpsc_soc_component, NULL, 0);
352 }
353 
354 static struct platform_driver au1xpsc_pcm_driver = {
355 	.driver	= {
356 		.name	= "au1xpsc-pcm",
357 	},
358 	.probe		= au1xpsc_pcm_drvprobe,
359 };
360 
361 module_platform_driver(au1xpsc_pcm_driver);
362 
363 MODULE_LICENSE("GPL");
364 MODULE_DESCRIPTION("Au12x0/Au1550 PSC Audio DMA driver");
365 MODULE_AUTHOR("Manuel Lauss");
366