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(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(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(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(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;
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(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
249static 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
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(substream->runtime,
274			       to_dmadata(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(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, &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(to_dmadata(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		card->dev, AU1XPSC_BUFFER_MIN_BYTES, (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(&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
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