xref: /openbmc/linux/sound/soc/au1x/psc-i2s.c (revision f15cbe6f1a4b4d9df59142fc8e4abb973302cf44)
1 /*
2  * Au12x0/Au1550 PSC ALSA ASoC audio support.
3  *
4  * (c) 2007-2008 MSC Vertriebsges.m.b.H.,
5  *	Manuel Lauss <mano@roarinelk.homelinux.net>
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  * Au1xxx-PSC I2S glue.
12  *
13  * NOTE: all of these drivers can only work with a SINGLE instance
14  *	 of a PSC. Multiple independent audio devices are impossible
15  *	 with ASoC v1.
16  * NOTE: so far only PSC slave mode (bit- and frameclock) is supported.
17  */
18 
19 #include <linux/init.h>
20 #include <linux/module.h>
21 #include <linux/suspend.h>
22 #include <sound/core.h>
23 #include <sound/pcm.h>
24 #include <sound/initval.h>
25 #include <sound/soc.h>
26 #include <asm/mach-au1x00/au1000.h>
27 #include <asm/mach-au1x00/au1xxx_psc.h>
28 
29 #include "psc.h"
30 
31 /* supported I2S DAI hardware formats */
32 #define AU1XPSC_I2S_DAIFMT \
33 	(SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_LEFT_J |	\
34 	 SND_SOC_DAIFMT_NB_NF)
35 
36 /* supported I2S direction */
37 #define AU1XPSC_I2S_DIR \
38 	(SND_SOC_DAIDIR_PLAYBACK | SND_SOC_DAIDIR_CAPTURE)
39 
40 #define AU1XPSC_I2S_RATES \
41 	SNDRV_PCM_RATE_8000_192000
42 
43 #define AU1XPSC_I2S_FMTS \
44 	(SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_LE)
45 
46 #define I2SSTAT_BUSY(stype)	\
47 	((stype) == PCM_TX ? PSC_I2SSTAT_TB : PSC_I2SSTAT_RB)
48 #define I2SPCR_START(stype)	\
49 	((stype) == PCM_TX ? PSC_I2SPCR_TS : PSC_I2SPCR_RS)
50 #define I2SPCR_STOP(stype)	\
51 	((stype) == PCM_TX ? PSC_I2SPCR_TP : PSC_I2SPCR_RP)
52 #define I2SPCR_CLRFIFO(stype)	\
53 	((stype) == PCM_TX ? PSC_I2SPCR_TC : PSC_I2SPCR_RC)
54 
55 
56 /* instance data. There can be only one, MacLeod!!!! */
57 static struct au1xpsc_audio_data *au1xpsc_i2s_workdata;
58 
59 static int au1xpsc_i2s_set_fmt(struct snd_soc_dai *cpu_dai,
60 			       unsigned int fmt)
61 {
62 	struct au1xpsc_audio_data *pscdata = au1xpsc_i2s_workdata;
63 	unsigned long ct;
64 	int ret;
65 
66 	ret = -EINVAL;
67 
68 	ct = pscdata->cfg;
69 
70 	ct &= ~(PSC_I2SCFG_XM | PSC_I2SCFG_MLJ);	/* left-justified */
71 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
72 	case SND_SOC_DAIFMT_I2S:
73 		ct |= PSC_I2SCFG_XM;	/* enable I2S mode */
74 		break;
75 	case SND_SOC_DAIFMT_MSB:
76 		break;
77 	case SND_SOC_DAIFMT_LSB:
78 		ct |= PSC_I2SCFG_MLJ;	/* LSB (right-) justified */
79 		break;
80 	default:
81 		goto out;
82 	}
83 
84 	ct &= ~(PSC_I2SCFG_BI | PSC_I2SCFG_WI);		/* IB-IF */
85 	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
86 	case SND_SOC_DAIFMT_NB_NF:
87 		ct |= PSC_I2SCFG_BI | PSC_I2SCFG_WI;
88 		break;
89 	case SND_SOC_DAIFMT_NB_IF:
90 		ct |= PSC_I2SCFG_BI;
91 		break;
92 	case SND_SOC_DAIFMT_IB_NF:
93 		ct |= PSC_I2SCFG_WI;
94 		break;
95 	case SND_SOC_DAIFMT_IB_IF:
96 		break;
97 	default:
98 		goto out;
99 	}
100 
101 	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
102 	case SND_SOC_DAIFMT_CBM_CFM:	/* CODEC master */
103 		ct |= PSC_I2SCFG_MS;	/* PSC I2S slave mode */
104 		break;
105 	case SND_SOC_DAIFMT_CBS_CFS:	/* CODEC slave */
106 		ct &= ~PSC_I2SCFG_MS;	/* PSC I2S Master mode */
107 		break;
108 	default:
109 		goto out;
110 	}
111 
112 	pscdata->cfg = ct;
113 	ret = 0;
114 out:
115 	return ret;
116 }
117 
118 static int au1xpsc_i2s_hw_params(struct snd_pcm_substream *substream,
119 				 struct snd_pcm_hw_params *params)
120 {
121 	struct au1xpsc_audio_data *pscdata = au1xpsc_i2s_workdata;
122 
123 	int cfgbits;
124 	unsigned long stat;
125 
126 	/* check if the PSC is already streaming data */
127 	stat = au_readl(I2S_STAT(pscdata));
128 	if (stat & (PSC_I2SSTAT_TB | PSC_I2SSTAT_RB)) {
129 		/* reject parameters not currently set up in hardware */
130 		cfgbits = au_readl(I2S_CFG(pscdata));
131 		if ((PSC_I2SCFG_GET_LEN(cfgbits) != params->msbits) ||
132 		    (params_rate(params) != pscdata->rate))
133 			return -EINVAL;
134 	} else {
135 		/* set sample bitdepth */
136 		pscdata->cfg &= ~(0x1f << 4);
137 		pscdata->cfg |= PSC_I2SCFG_SET_LEN(params->msbits);
138 		/* remember current rate for other stream */
139 		pscdata->rate = params_rate(params);
140 	}
141 	return 0;
142 }
143 
144 /* Configure PSC late:  on my devel systems the codec  is I2S master and
145  * supplies the i2sbitclock __AND__ i2sMclk (!) to the PSC unit.  ASoC
146  * uses aggressive PM and  switches the codec off  when it is not in use
147  * which also means the PSC unit doesn't get any clocks and is therefore
148  * dead. That's why this chunk here gets called from the trigger callback
149  * because I can be reasonably certain the codec is driving the clocks.
150  */
151 static int au1xpsc_i2s_configure(struct au1xpsc_audio_data *pscdata)
152 {
153 	unsigned long tmo;
154 
155 	/* bring PSC out of sleep, and configure I2S unit */
156 	au_writel(PSC_CTRL_ENABLE, PSC_CTRL(pscdata));
157 	au_sync();
158 
159 	tmo = 1000000;
160 	while (!(au_readl(I2S_STAT(pscdata)) & PSC_I2SSTAT_SR) && tmo)
161 		tmo--;
162 
163 	if (!tmo)
164 		goto psc_err;
165 
166 	au_writel(0, I2S_CFG(pscdata));
167 	au_sync();
168 	au_writel(pscdata->cfg | PSC_I2SCFG_DE_ENABLE, I2S_CFG(pscdata));
169 	au_sync();
170 
171 	/* wait for I2S controller to become ready */
172 	tmo = 1000000;
173 	while (!(au_readl(I2S_STAT(pscdata)) & PSC_I2SSTAT_DR) && tmo)
174 		tmo--;
175 
176 	if (tmo)
177 		return 0;
178 
179 psc_err:
180 	au_writel(0, I2S_CFG(pscdata));
181 	au_writel(PSC_CTRL_SUSPEND, PSC_CTRL(pscdata));
182 	au_sync();
183 	return -ETIMEDOUT;
184 }
185 
186 static int au1xpsc_i2s_start(struct au1xpsc_audio_data *pscdata, int stype)
187 {
188 	unsigned long tmo, stat;
189 	int ret;
190 
191 	ret = 0;
192 
193 	/* if both TX and RX are idle, configure the PSC  */
194 	stat = au_readl(I2S_STAT(pscdata));
195 	if (!(stat & (PSC_I2SSTAT_TB | PSC_I2SSTAT_RB))) {
196 		ret = au1xpsc_i2s_configure(pscdata);
197 		if (ret)
198 			goto out;
199 	}
200 
201 	au_writel(I2SPCR_CLRFIFO(stype), I2S_PCR(pscdata));
202 	au_sync();
203 	au_writel(I2SPCR_START(stype), I2S_PCR(pscdata));
204 	au_sync();
205 
206 	/* wait for start confirmation */
207 	tmo = 1000000;
208 	while (!(au_readl(I2S_STAT(pscdata)) & I2SSTAT_BUSY(stype)) && tmo)
209 		tmo--;
210 
211 	if (!tmo) {
212 		au_writel(I2SPCR_STOP(stype), I2S_PCR(pscdata));
213 		au_sync();
214 		ret = -ETIMEDOUT;
215 	}
216 out:
217 	return ret;
218 }
219 
220 static int au1xpsc_i2s_stop(struct au1xpsc_audio_data *pscdata, int stype)
221 {
222 	unsigned long tmo, stat;
223 
224 	au_writel(I2SPCR_STOP(stype), I2S_PCR(pscdata));
225 	au_sync();
226 
227 	/* wait for stop confirmation */
228 	tmo = 1000000;
229 	while ((au_readl(I2S_STAT(pscdata)) & I2SSTAT_BUSY(stype)) && tmo)
230 		tmo--;
231 
232 	/* if both TX and RX are idle, disable PSC */
233 	stat = au_readl(I2S_STAT(pscdata));
234 	if (!(stat & (PSC_I2SSTAT_TB | PSC_I2SSTAT_RB))) {
235 		au_writel(0, I2S_CFG(pscdata));
236 		au_sync();
237 		au_writel(PSC_CTRL_SUSPEND, PSC_CTRL(pscdata));
238 		au_sync();
239 	}
240 	return 0;
241 }
242 
243 static int au1xpsc_i2s_trigger(struct snd_pcm_substream *substream, int cmd)
244 {
245 	struct au1xpsc_audio_data *pscdata = au1xpsc_i2s_workdata;
246 	int ret, stype = SUBSTREAM_TYPE(substream);
247 
248 	switch (cmd) {
249 	case SNDRV_PCM_TRIGGER_START:
250 	case SNDRV_PCM_TRIGGER_RESUME:
251 		ret = au1xpsc_i2s_start(pscdata, stype);
252 		break;
253 	case SNDRV_PCM_TRIGGER_STOP:
254 	case SNDRV_PCM_TRIGGER_SUSPEND:
255 		ret = au1xpsc_i2s_stop(pscdata, stype);
256 		break;
257 	default:
258 		ret = -EINVAL;
259 	}
260 	return ret;
261 }
262 
263 static int au1xpsc_i2s_probe(struct platform_device *pdev,
264 			     struct snd_soc_dai *dai)
265 {
266 	struct resource *r;
267 	unsigned long sel;
268 	int ret;
269 
270 	if (au1xpsc_i2s_workdata)
271 		return -EBUSY;
272 
273 	au1xpsc_i2s_workdata =
274 		kzalloc(sizeof(struct au1xpsc_audio_data), GFP_KERNEL);
275 	if (!au1xpsc_i2s_workdata)
276 		return -ENOMEM;
277 
278 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
279 	if (!r) {
280 		ret = -ENODEV;
281 		goto out0;
282 	}
283 
284 	ret = -EBUSY;
285 	au1xpsc_i2s_workdata->ioarea =
286 		request_mem_region(r->start, r->end - r->start + 1,
287 					"au1xpsc_i2s");
288 	if (!au1xpsc_i2s_workdata->ioarea)
289 		goto out0;
290 
291 	au1xpsc_i2s_workdata->mmio = ioremap(r->start, 0xffff);
292 	if (!au1xpsc_i2s_workdata->mmio)
293 		goto out1;
294 
295 	/* preserve PSC clock source set up by platform (dev.platform_data
296 	 * is already occupied by soc layer)
297 	 */
298 	sel = au_readl(PSC_SEL(au1xpsc_i2s_workdata)) & PSC_SEL_CLK_MASK;
299 	au_writel(PSC_CTRL_DISABLE, PSC_CTRL(au1xpsc_i2s_workdata));
300 	au_sync();
301 	au_writel(PSC_SEL_PS_I2SMODE | sel, PSC_SEL(au1xpsc_i2s_workdata));
302 	au_writel(0, I2S_CFG(au1xpsc_i2s_workdata));
303 	au_sync();
304 
305 	/* preconfigure: set max rx/tx fifo depths */
306 	au1xpsc_i2s_workdata->cfg |=
307 			PSC_I2SCFG_RT_FIFO8 | PSC_I2SCFG_TT_FIFO8;
308 
309 	/* don't wait for I2S core to become ready now; clocks may not
310 	 * be running yet; depending on clock input for PSC a wait might
311 	 * time out.
312 	 */
313 
314 	return 0;
315 
316 out1:
317 	release_resource(au1xpsc_i2s_workdata->ioarea);
318 	kfree(au1xpsc_i2s_workdata->ioarea);
319 out0:
320 	kfree(au1xpsc_i2s_workdata);
321 	au1xpsc_i2s_workdata = NULL;
322 	return ret;
323 }
324 
325 static void au1xpsc_i2s_remove(struct platform_device *pdev,
326 			       struct snd_soc_dai *dai)
327 {
328 	au_writel(0, I2S_CFG(au1xpsc_i2s_workdata));
329 	au_sync();
330 	au_writel(PSC_CTRL_DISABLE, PSC_CTRL(au1xpsc_i2s_workdata));
331 	au_sync();
332 
333 	iounmap(au1xpsc_i2s_workdata->mmio);
334 	release_resource(au1xpsc_i2s_workdata->ioarea);
335 	kfree(au1xpsc_i2s_workdata->ioarea);
336 	kfree(au1xpsc_i2s_workdata);
337 	au1xpsc_i2s_workdata = NULL;
338 }
339 
340 static int au1xpsc_i2s_suspend(struct platform_device *pdev,
341 			       struct snd_soc_dai *cpu_dai)
342 {
343 	/* save interesting register and disable PSC */
344 	au1xpsc_i2s_workdata->pm[0] =
345 		au_readl(PSC_SEL(au1xpsc_i2s_workdata));
346 
347 	au_writel(0, I2S_CFG(au1xpsc_i2s_workdata));
348 	au_sync();
349 	au_writel(PSC_CTRL_DISABLE, PSC_CTRL(au1xpsc_i2s_workdata));
350 	au_sync();
351 
352 	return 0;
353 }
354 
355 static int au1xpsc_i2s_resume(struct platform_device *pdev,
356 			      struct snd_soc_dai *cpu_dai)
357 {
358 	/* select I2S mode and PSC clock */
359 	au_writel(PSC_CTRL_DISABLE, PSC_CTRL(au1xpsc_i2s_workdata));
360 	au_sync();
361 	au_writel(0, PSC_SEL(au1xpsc_i2s_workdata));
362 	au_sync();
363 	au_writel(au1xpsc_i2s_workdata->pm[0],
364 			PSC_SEL(au1xpsc_i2s_workdata));
365 	au_sync();
366 
367 	return 0;
368 }
369 
370 struct snd_soc_dai au1xpsc_i2s_dai = {
371 	.name			= "au1xpsc_i2s",
372 	.type			= SND_SOC_DAI_I2S,
373 	.probe			= au1xpsc_i2s_probe,
374 	.remove			= au1xpsc_i2s_remove,
375 	.suspend		= au1xpsc_i2s_suspend,
376 	.resume			= au1xpsc_i2s_resume,
377 	.playback = {
378 		.rates		= AU1XPSC_I2S_RATES,
379 		.formats	= AU1XPSC_I2S_FMTS,
380 		.channels_min	= 2,
381 		.channels_max	= 8,	/* 2 without external help */
382 	},
383 	.capture = {
384 		.rates		= AU1XPSC_I2S_RATES,
385 		.formats	= AU1XPSC_I2S_FMTS,
386 		.channels_min	= 2,
387 		.channels_max	= 8,	/* 2 without external help */
388 	},
389 	.ops = {
390 		.trigger	= au1xpsc_i2s_trigger,
391 		.hw_params	= au1xpsc_i2s_hw_params,
392 	},
393 	.dai_ops = {
394 		.set_fmt	= au1xpsc_i2s_set_fmt,
395 	},
396 };
397 EXPORT_SYMBOL(au1xpsc_i2s_dai);
398 
399 static int __init au1xpsc_i2s_init(void)
400 {
401 	au1xpsc_i2s_workdata = NULL;
402 	return 0;
403 }
404 
405 static void __exit au1xpsc_i2s_exit(void)
406 {
407 }
408 
409 module_init(au1xpsc_i2s_init);
410 module_exit(au1xpsc_i2s_exit);
411 
412 MODULE_LICENSE("GPL");
413 MODULE_DESCRIPTION("Au12x0/Au1550 PSC I2S ALSA ASoC audio driver");
414 MODULE_AUTHOR("Manuel Lauss <mano@roarinelk.homelinux.net>");
415