xref: /openbmc/linux/sound/soc/au1x/dbdma2.c (revision e287d046)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Au12x0/Au1550 PSC ALSA ASoC audio support.
4  *
5  * (c) 2007-2008 MSC Vertriebsges.m.b.H.,
6  *	Manuel Lauss <manuel.lauss@gmail.com>
7  *
8  * DMA glue for Au1x-PSC audio.
9  */
10 
11 
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/platform_device.h>
15 #include <linux/slab.h>
16 #include <linux/dma-mapping.h>
17 
18 #include <sound/core.h>
19 #include <sound/pcm.h>
20 #include <sound/pcm_params.h>
21 #include <sound/soc.h>
22 
23 #include <asm/mach-au1x00/au1000.h>
24 #include <asm/mach-au1x00/au1xxx_dbdma.h>
25 #include <asm/mach-au1x00/au1xxx_psc.h>
26 
27 #include "psc.h"
28 
29 /*#define PCM_DEBUG*/
30 
31 #define DRV_NAME "dbdma2"
32 
33 #define MSG(x...)	printk(KERN_INFO "au1xpsc_pcm: " x)
34 #ifdef PCM_DEBUG
35 #define DBG		MSG
36 #else
37 #define DBG(x...)	do {} while (0)
38 #endif
39 
40 struct au1xpsc_audio_dmadata {
41 	/* DDMA control data */
42 	unsigned int ddma_id;		/* DDMA direction ID for this PSC */
43 	u32 ddma_chan;			/* DDMA context */
44 
45 	/* PCM context (for irq handlers) */
46 	struct snd_pcm_substream *substream;
47 	unsigned long curr_period;	/* current segment DDMA is working on */
48 	unsigned long q_period;		/* queue period(s) */
49 	dma_addr_t dma_area;		/* address of queued DMA area */
50 	dma_addr_t dma_area_s;		/* start address of DMA area */
51 	unsigned long pos;		/* current byte position being played */
52 	unsigned long periods;		/* number of SG segments in total */
53 	unsigned long period_bytes;	/* size in bytes of one SG segment */
54 
55 	/* runtime data */
56 	int msbits;
57 };
58 
59 /*
60  * These settings are somewhat okay, at least on my machine audio plays
61  * almost skip-free. Especially the 64kB buffer seems to help a LOT.
62  */
63 #define AU1XPSC_PERIOD_MIN_BYTES	1024
64 #define AU1XPSC_BUFFER_MIN_BYTES	65536
65 
66 /* PCM hardware DMA capabilities - platform specific */
67 static const struct snd_pcm_hardware au1xpsc_pcm_hardware = {
68 	.info		  = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
69 			    SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BATCH,
70 	.period_bytes_min = AU1XPSC_PERIOD_MIN_BYTES,
71 	.period_bytes_max = 4096 * 1024 - 1,
72 	.periods_min	  = 2,
73 	.periods_max	  = 4096,	/* 2 to as-much-as-you-like */
74 	.buffer_bytes_max = 4096 * 1024 - 1,
75 	.fifo_size	  = 16,		/* fifo entries of AC97/I2S PSC */
76 };
77 
au1x_pcm_queue_tx(struct au1xpsc_audio_dmadata * cd)78 static void au1x_pcm_queue_tx(struct au1xpsc_audio_dmadata *cd)
79 {
80 	au1xxx_dbdma_put_source(cd->ddma_chan, cd->dma_area,
81 				cd->period_bytes, DDMA_FLAGS_IE);
82 
83 	/* update next-to-queue period */
84 	++cd->q_period;
85 	cd->dma_area += cd->period_bytes;
86 	if (cd->q_period >= cd->periods) {
87 		cd->q_period = 0;
88 		cd->dma_area = cd->dma_area_s;
89 	}
90 }
91 
au1x_pcm_queue_rx(struct au1xpsc_audio_dmadata * cd)92 static void au1x_pcm_queue_rx(struct au1xpsc_audio_dmadata *cd)
93 {
94 	au1xxx_dbdma_put_dest(cd->ddma_chan, cd->dma_area,
95 			      cd->period_bytes, DDMA_FLAGS_IE);
96 
97 	/* update next-to-queue period */
98 	++cd->q_period;
99 	cd->dma_area += cd->period_bytes;
100 	if (cd->q_period >= cd->periods) {
101 		cd->q_period = 0;
102 		cd->dma_area = cd->dma_area_s;
103 	}
104 }
105 
au1x_pcm_dmatx_cb(int irq,void * dev_id)106 static void au1x_pcm_dmatx_cb(int irq, void *dev_id)
107 {
108 	struct au1xpsc_audio_dmadata *cd = dev_id;
109 
110 	cd->pos += cd->period_bytes;
111 	if (++cd->curr_period >= cd->periods) {
112 		cd->pos = 0;
113 		cd->curr_period = 0;
114 	}
115 	snd_pcm_period_elapsed(cd->substream);
116 	au1x_pcm_queue_tx(cd);
117 }
118 
au1x_pcm_dmarx_cb(int irq,void * dev_id)119 static void au1x_pcm_dmarx_cb(int irq, void *dev_id)
120 {
121 	struct au1xpsc_audio_dmadata *cd = dev_id;
122 
123 	cd->pos += cd->period_bytes;
124 	if (++cd->curr_period >= cd->periods) {
125 		cd->pos = 0;
126 		cd->curr_period = 0;
127 	}
128 	snd_pcm_period_elapsed(cd->substream);
129 	au1x_pcm_queue_rx(cd);
130 }
131 
au1x_pcm_dbdma_free(struct au1xpsc_audio_dmadata * pcd)132 static void au1x_pcm_dbdma_free(struct au1xpsc_audio_dmadata *pcd)
133 {
134 	if (pcd->ddma_chan) {
135 		au1xxx_dbdma_stop(pcd->ddma_chan);
136 		au1xxx_dbdma_reset(pcd->ddma_chan);
137 		au1xxx_dbdma_chan_free(pcd->ddma_chan);
138 		pcd->ddma_chan = 0;
139 		pcd->msbits = 0;
140 	}
141 }
142 
143 /* in case of missing DMA ring or changed TX-source / RX-dest bit widths,
144  * allocate (or reallocate) a 2-descriptor DMA ring with bit depth according
145  * to ALSA-supplied sample depth.  This is due to limitations in the dbdma api
146  * (cannot adjust source/dest widths of already allocated descriptor ring).
147  */
au1x_pcm_dbdma_realloc(struct au1xpsc_audio_dmadata * pcd,int stype,int msbits)148 static int au1x_pcm_dbdma_realloc(struct au1xpsc_audio_dmadata *pcd,
149 				 int stype, int msbits)
150 {
151 	/* DMA only in 8/16/32 bit widths */
152 	if (msbits == 24)
153 		msbits = 32;
154 
155 	/* check current config: correct bits and descriptors allocated? */
156 	if ((pcd->ddma_chan) && (msbits == pcd->msbits))
157 		goto out;	/* all ok! */
158 
159 	au1x_pcm_dbdma_free(pcd);
160 
161 	if (stype == SNDRV_PCM_STREAM_CAPTURE)
162 		pcd->ddma_chan = au1xxx_dbdma_chan_alloc(pcd->ddma_id,
163 					DSCR_CMD0_ALWAYS,
164 					au1x_pcm_dmarx_cb, (void *)pcd);
165 	else
166 		pcd->ddma_chan = au1xxx_dbdma_chan_alloc(DSCR_CMD0_ALWAYS,
167 					pcd->ddma_id,
168 					au1x_pcm_dmatx_cb, (void *)pcd);
169 
170 	if (!pcd->ddma_chan)
171 		return -ENOMEM;
172 
173 	au1xxx_dbdma_set_devwidth(pcd->ddma_chan, msbits);
174 	au1xxx_dbdma_ring_alloc(pcd->ddma_chan, 2);
175 
176 	pcd->msbits = msbits;
177 
178 	au1xxx_dbdma_stop(pcd->ddma_chan);
179 	au1xxx_dbdma_reset(pcd->ddma_chan);
180 
181 out:
182 	return 0;
183 }
184 
to_dmadata(struct snd_pcm_substream * ss,struct snd_soc_component * component)185 static inline struct au1xpsc_audio_dmadata *to_dmadata(struct snd_pcm_substream *ss,
186 						       struct snd_soc_component *component)
187 {
188 	struct au1xpsc_audio_dmadata *pcd = snd_soc_component_get_drvdata(component);
189 	return &pcd[ss->stream];
190 }
191 
au1xpsc_pcm_hw_params(struct snd_soc_component * component,struct snd_pcm_substream * substream,struct snd_pcm_hw_params * params)192 static int au1xpsc_pcm_hw_params(struct snd_soc_component *component,
193 				 struct snd_pcm_substream *substream,
194 				 struct snd_pcm_hw_params *params)
195 {
196 	struct snd_pcm_runtime *runtime = substream->runtime;
197 	struct au1xpsc_audio_dmadata *pcd;
198 	int stype, ret;
199 
200 	stype = substream->stream;
201 	pcd = to_dmadata(substream, component);
202 
203 	DBG("runtime->dma_area = 0x%08lx dma_addr_t = 0x%08lx dma_size = %zu "
204 	    "runtime->min_align %lu\n",
205 		(unsigned long)runtime->dma_area,
206 		(unsigned long)runtime->dma_addr, runtime->dma_bytes,
207 		runtime->min_align);
208 
209 	DBG("bits %d  frags %d  frag_bytes %d  is_rx %d\n", params->msbits,
210 		params_periods(params), params_period_bytes(params), stype);
211 
212 	ret = au1x_pcm_dbdma_realloc(pcd, stype, params->msbits);
213 	if (ret) {
214 		MSG("DDMA channel (re)alloc failed!\n");
215 		goto out;
216 	}
217 
218 	pcd->substream = substream;
219 	pcd->period_bytes = params_period_bytes(params);
220 	pcd->periods = params_periods(params);
221 	pcd->dma_area_s = pcd->dma_area = runtime->dma_addr;
222 	pcd->q_period = 0;
223 	pcd->curr_period = 0;
224 	pcd->pos = 0;
225 
226 	ret = 0;
227 out:
228 	return ret;
229 }
230 
au1xpsc_pcm_prepare(struct snd_soc_component * component,struct snd_pcm_substream * substream)231 static int au1xpsc_pcm_prepare(struct snd_soc_component *component,
232 			       struct snd_pcm_substream *substream)
233 {
234 	struct au1xpsc_audio_dmadata *pcd = to_dmadata(substream, component);
235 
236 	au1xxx_dbdma_reset(pcd->ddma_chan);
237 
238 	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
239 		au1x_pcm_queue_rx(pcd);
240 		au1x_pcm_queue_rx(pcd);
241 	} else {
242 		au1x_pcm_queue_tx(pcd);
243 		au1x_pcm_queue_tx(pcd);
244 	}
245 
246 	return 0;
247 }
248 
au1xpsc_pcm_trigger(struct snd_soc_component * component,struct snd_pcm_substream * substream,int cmd)249 static int au1xpsc_pcm_trigger(struct snd_soc_component *component,
250 			       struct snd_pcm_substream *substream, int cmd)
251 {
252 	u32 c = to_dmadata(substream, component)->ddma_chan;
253 
254 	switch (cmd) {
255 	case SNDRV_PCM_TRIGGER_START:
256 	case SNDRV_PCM_TRIGGER_RESUME:
257 		au1xxx_dbdma_start(c);
258 		break;
259 	case SNDRV_PCM_TRIGGER_STOP:
260 	case SNDRV_PCM_TRIGGER_SUSPEND:
261 		au1xxx_dbdma_stop(c);
262 		break;
263 	default:
264 		return -EINVAL;
265 	}
266 	return 0;
267 }
268 
269 static snd_pcm_uframes_t
au1xpsc_pcm_pointer(struct snd_soc_component * component,struct snd_pcm_substream * substream)270 au1xpsc_pcm_pointer(struct snd_soc_component *component,
271 		    struct snd_pcm_substream *substream)
272 {
273 	return bytes_to_frames(substream->runtime,
274 			       to_dmadata(substream, component)->pos);
275 }
276 
au1xpsc_pcm_open(struct snd_soc_component * component,struct snd_pcm_substream * substream)277 static int au1xpsc_pcm_open(struct snd_soc_component *component,
278 			    struct snd_pcm_substream *substream)
279 {
280 	struct au1xpsc_audio_dmadata *pcd = to_dmadata(substream, component);
281 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
282 	int stype = substream->stream, *dmaids;
283 
284 	dmaids = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
285 	if (!dmaids)
286 		return -ENODEV;	/* whoa, has ordering changed? */
287 
288 	pcd->ddma_id = dmaids[stype];
289 
290 	snd_soc_set_runtime_hwparams(substream, &au1xpsc_pcm_hardware);
291 	return 0;
292 }
293 
au1xpsc_pcm_close(struct snd_soc_component * component,struct snd_pcm_substream * substream)294 static int au1xpsc_pcm_close(struct snd_soc_component *component,
295 			     struct snd_pcm_substream *substream)
296 {
297 	au1x_pcm_dbdma_free(to_dmadata(substream, component));
298 	return 0;
299 }
300 
au1xpsc_pcm_new(struct snd_soc_component * component,struct snd_soc_pcm_runtime * rtd)301 static int au1xpsc_pcm_new(struct snd_soc_component *component,
302 			   struct snd_soc_pcm_runtime *rtd)
303 {
304 	struct snd_card *card = rtd->card->snd_card;
305 	struct snd_pcm *pcm = rtd->pcm;
306 
307 	snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV,
308 		card->dev, AU1XPSC_BUFFER_MIN_BYTES, (4096 * 1024) - 1);
309 
310 	return 0;
311 }
312 
313 /* au1xpsc audio platform */
314 static struct snd_soc_component_driver au1xpsc_soc_component = {
315 	.name		= DRV_NAME,
316 	.open		= au1xpsc_pcm_open,
317 	.close		= au1xpsc_pcm_close,
318 	.hw_params	= au1xpsc_pcm_hw_params,
319 	.prepare	= au1xpsc_pcm_prepare,
320 	.trigger	= au1xpsc_pcm_trigger,
321 	.pointer	= au1xpsc_pcm_pointer,
322 	.pcm_construct	= au1xpsc_pcm_new,
323 };
324 
au1xpsc_pcm_drvprobe(struct platform_device * pdev)325 static int au1xpsc_pcm_drvprobe(struct platform_device *pdev)
326 {
327 	struct au1xpsc_audio_dmadata *dmadata;
328 
329 	dmadata = devm_kcalloc(&pdev->dev,
330 			       2, sizeof(struct au1xpsc_audio_dmadata),
331 			       GFP_KERNEL);
332 	if (!dmadata)
333 		return -ENOMEM;
334 
335 	platform_set_drvdata(pdev, dmadata);
336 
337 	return devm_snd_soc_register_component(&pdev->dev,
338 					&au1xpsc_soc_component, NULL, 0);
339 }
340 
341 static struct platform_driver au1xpsc_pcm_driver = {
342 	.driver	= {
343 		.name	= "au1xpsc-pcm",
344 	},
345 	.probe		= au1xpsc_pcm_drvprobe,
346 };
347 
348 module_platform_driver(au1xpsc_pcm_driver);
349 
350 MODULE_LICENSE("GPL");
351 MODULE_DESCRIPTION("Au12x0/Au1550 PSC Audio DMA driver");
352 MODULE_AUTHOR("Manuel Lauss");
353