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
40struct 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 */
67static 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
78static 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
92static 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
106static 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(substream: cd->substream);
116 au1x_pcm_queue_tx(cd);
117}
118
119static 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(substream: cd->substream);
129 au1x_pcm_queue_rx(cd);
130}
131
132static 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 */
148static 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
181out:
182 return 0;
183}
184
185static 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(c: component);
189 return &pcd[ss->stream];
190}
191
192static 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(ss: 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, msbits: 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(p: params);
220 pcd->periods = params_periods(p: 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;
227out:
228 return ret;
229}
230
231static int au1xpsc_pcm_prepare(struct snd_soc_component *component,
232 struct snd_pcm_substream *substream)
233{
234 struct au1xpsc_audio_dmadata *pcd = to_dmadata(ss: substream, component);
235
236 au1xxx_dbdma_reset(pcd->ddma_chan);
237
238 if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
239 au1x_pcm_queue_rx(cd: pcd);
240 au1x_pcm_queue_rx(cd: pcd);
241 } else {
242 au1x_pcm_queue_tx(cd: pcd);
243 au1x_pcm_queue_tx(cd: pcd);
244 }
245
246 return 0;
247}
248
249static int au1xpsc_pcm_trigger(struct snd_soc_component *component,
250 struct snd_pcm_substream *substream, int cmd)
251{
252 u32 c = to_dmadata(ss: 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
269static snd_pcm_uframes_t
270au1xpsc_pcm_pointer(struct snd_soc_component *component,
271 struct snd_pcm_substream *substream)
272{
273 return bytes_to_frames(runtime: substream->runtime,
274 size: to_dmadata(ss: substream, component)->pos);
275}
276
277static int au1xpsc_pcm_open(struct snd_soc_component *component,
278 struct snd_pcm_substream *substream)
279{
280 struct au1xpsc_audio_dmadata *pcd = to_dmadata(ss: substream, component);
281 struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
282 int stype = substream->stream, *dmaids;
283
284 dmaids = snd_soc_dai_get_dma_data(snd_soc_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, hw: &au1xpsc_pcm_hardware);
291 return 0;
292}
293
294static int au1xpsc_pcm_close(struct snd_soc_component *component,
295 struct snd_pcm_substream *substream)
296{
297 au1x_pcm_dbdma_free(pcd: to_dmadata(ss: substream, component));
298 return 0;
299}
300
301static 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 data: card->dev, AU1XPSC_BUFFER_MIN_BYTES, max: (4096 * 1024) - 1);
309
310 return 0;
311}
312
313/* au1xpsc audio platform */
314static 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
325static int au1xpsc_pcm_drvprobe(struct platform_device *pdev)
326{
327 struct au1xpsc_audio_dmadata *dmadata;
328
329 dmadata = devm_kcalloc(dev: &pdev->dev,
330 n: 2, size: sizeof(struct au1xpsc_audio_dmadata),
331 GFP_KERNEL);
332 if (!dmadata)
333 return -ENOMEM;
334
335 platform_set_drvdata(pdev, data: dmadata);
336
337 return devm_snd_soc_register_component(dev: &pdev->dev,
338 component_driver: &au1xpsc_soc_component, NULL, num_dai: 0);
339}
340
341static struct platform_driver au1xpsc_pcm_driver = {
342 .driver = {
343 .name = "au1xpsc-pcm",
344 },
345 .probe = au1xpsc_pcm_drvprobe,
346};
347
348module_platform_driver(au1xpsc_pcm_driver);
349
350MODULE_LICENSE("GPL");
351MODULE_DESCRIPTION("Au12x0/Au1550 PSC Audio DMA driver");
352MODULE_AUTHOR("Manuel Lauss");
353

source code of linux/sound/soc/au1x/dbdma2.c