xref: /openbmc/linux/sound/soc/au1x/psc-ac97.c (revision ebd09753)
1 /*
2  * Au12x0/Au1550 PSC ALSA ASoC audio support.
3  *
4  * (c) 2007-2009 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  * Au1xxx-PSC AC97 glue.
12  *
13  */
14 
15 #include <linux/init.h>
16 #include <linux/module.h>
17 #include <linux/slab.h>
18 #include <linux/device.h>
19 #include <linux/delay.h>
20 #include <linux/mutex.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 /* how often to retry failed codec register reads/writes */
32 #define AC97_RW_RETRIES	5
33 
34 #define AC97_DIR	\
35 	(SND_SOC_DAIDIR_PLAYBACK | SND_SOC_DAIDIR_CAPTURE)
36 
37 #define AC97_RATES	\
38 	SNDRV_PCM_RATE_8000_48000
39 
40 #define AC97_FMTS	\
41 	(SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S20_3BE)
42 
43 #define AC97PCR_START(stype)	\
44 	((stype) == SNDRV_PCM_STREAM_PLAYBACK ? PSC_AC97PCR_TS : PSC_AC97PCR_RS)
45 #define AC97PCR_STOP(stype)	\
46 	((stype) == SNDRV_PCM_STREAM_PLAYBACK ? PSC_AC97PCR_TP : PSC_AC97PCR_RP)
47 #define AC97PCR_CLRFIFO(stype)	\
48 	((stype) == SNDRV_PCM_STREAM_PLAYBACK ? PSC_AC97PCR_TC : PSC_AC97PCR_RC)
49 
50 #define AC97STAT_BUSY(stype)	\
51 	((stype) == SNDRV_PCM_STREAM_PLAYBACK ? PSC_AC97STAT_TB : PSC_AC97STAT_RB)
52 
53 /* instance data. There can be only one, MacLeod!!!! */
54 static struct au1xpsc_audio_data *au1xpsc_ac97_workdata;
55 
56 #if 0
57 
58 /* this could theoretically work, but ac97->bus->card->private_data can be NULL
59  * when snd_ac97_mixer() is called; I don't know if the rest further down the
60  * chain are always valid either.
61  */
62 static inline struct au1xpsc_audio_data *ac97_to_pscdata(struct snd_ac97 *x)
63 {
64 	struct snd_soc_card *c = x->bus->card->private_data;
65 	return snd_soc_dai_get_drvdata(c->rtd->cpu_dai);
66 }
67 
68 #else
69 
70 #define ac97_to_pscdata(x)	au1xpsc_ac97_workdata
71 
72 #endif
73 
74 /* AC97 controller reads codec register */
75 static unsigned short au1xpsc_ac97_read(struct snd_ac97 *ac97,
76 					unsigned short reg)
77 {
78 	struct au1xpsc_audio_data *pscdata = ac97_to_pscdata(ac97);
79 	unsigned short retry, tmo;
80 	unsigned long data;
81 
82 	__raw_writel(PSC_AC97EVNT_CD, AC97_EVNT(pscdata));
83 	wmb(); /* drain writebuffer */
84 
85 	retry = AC97_RW_RETRIES;
86 	do {
87 		mutex_lock(&pscdata->lock);
88 
89 		__raw_writel(PSC_AC97CDC_RD | PSC_AC97CDC_INDX(reg),
90 			  AC97_CDC(pscdata));
91 		wmb(); /* drain writebuffer */
92 
93 		tmo = 20;
94 		do {
95 			udelay(21);
96 			if (__raw_readl(AC97_EVNT(pscdata)) & PSC_AC97EVNT_CD)
97 				break;
98 		} while (--tmo);
99 
100 		data = __raw_readl(AC97_CDC(pscdata));
101 
102 		__raw_writel(PSC_AC97EVNT_CD, AC97_EVNT(pscdata));
103 		wmb(); /* drain writebuffer */
104 
105 		mutex_unlock(&pscdata->lock);
106 
107 		if (reg != ((data >> 16) & 0x7f))
108 			tmo = 1;	/* wrong register, try again */
109 
110 	} while (--retry && !tmo);
111 
112 	return retry ? data & 0xffff : 0xffff;
113 }
114 
115 /* AC97 controller writes to codec register */
116 static void au1xpsc_ac97_write(struct snd_ac97 *ac97, unsigned short reg,
117 				unsigned short val)
118 {
119 	struct au1xpsc_audio_data *pscdata = ac97_to_pscdata(ac97);
120 	unsigned int tmo, retry;
121 
122 	__raw_writel(PSC_AC97EVNT_CD, AC97_EVNT(pscdata));
123 	wmb(); /* drain writebuffer */
124 
125 	retry = AC97_RW_RETRIES;
126 	do {
127 		mutex_lock(&pscdata->lock);
128 
129 		__raw_writel(PSC_AC97CDC_INDX(reg) | (val & 0xffff),
130 			  AC97_CDC(pscdata));
131 		wmb(); /* drain writebuffer */
132 
133 		tmo = 20;
134 		do {
135 			udelay(21);
136 			if (__raw_readl(AC97_EVNT(pscdata)) & PSC_AC97EVNT_CD)
137 				break;
138 		} while (--tmo);
139 
140 		__raw_writel(PSC_AC97EVNT_CD, AC97_EVNT(pscdata));
141 		wmb(); /* drain writebuffer */
142 
143 		mutex_unlock(&pscdata->lock);
144 	} while (--retry && !tmo);
145 }
146 
147 /* AC97 controller asserts a warm reset */
148 static void au1xpsc_ac97_warm_reset(struct snd_ac97 *ac97)
149 {
150 	struct au1xpsc_audio_data *pscdata = ac97_to_pscdata(ac97);
151 
152 	__raw_writel(PSC_AC97RST_SNC, AC97_RST(pscdata));
153 	wmb(); /* drain writebuffer */
154 	msleep(10);
155 	__raw_writel(0, AC97_RST(pscdata));
156 	wmb(); /* drain writebuffer */
157 }
158 
159 static void au1xpsc_ac97_cold_reset(struct snd_ac97 *ac97)
160 {
161 	struct au1xpsc_audio_data *pscdata = ac97_to_pscdata(ac97);
162 	int i;
163 
164 	/* disable PSC during cold reset */
165 	__raw_writel(0, AC97_CFG(au1xpsc_ac97_workdata));
166 	wmb(); /* drain writebuffer */
167 	__raw_writel(PSC_CTRL_DISABLE, PSC_CTRL(pscdata));
168 	wmb(); /* drain writebuffer */
169 
170 	/* issue cold reset */
171 	__raw_writel(PSC_AC97RST_RST, AC97_RST(pscdata));
172 	wmb(); /* drain writebuffer */
173 	msleep(500);
174 	__raw_writel(0, AC97_RST(pscdata));
175 	wmb(); /* drain writebuffer */
176 
177 	/* enable PSC */
178 	__raw_writel(PSC_CTRL_ENABLE, PSC_CTRL(pscdata));
179 	wmb(); /* drain writebuffer */
180 
181 	/* wait for PSC to indicate it's ready */
182 	i = 1000;
183 	while (!((__raw_readl(AC97_STAT(pscdata)) & PSC_AC97STAT_SR)) && (--i))
184 		msleep(1);
185 
186 	if (i == 0) {
187 		printk(KERN_ERR "au1xpsc-ac97: PSC not ready!\n");
188 		return;
189 	}
190 
191 	/* enable the ac97 function */
192 	__raw_writel(pscdata->cfg | PSC_AC97CFG_DE_ENABLE, AC97_CFG(pscdata));
193 	wmb(); /* drain writebuffer */
194 
195 	/* wait for AC97 core to become ready */
196 	i = 1000;
197 	while (!((__raw_readl(AC97_STAT(pscdata)) & PSC_AC97STAT_DR)) && (--i))
198 		msleep(1);
199 	if (i == 0)
200 		printk(KERN_ERR "au1xpsc-ac97: AC97 ctrl not ready\n");
201 }
202 
203 /* AC97 controller operations */
204 static struct snd_ac97_bus_ops psc_ac97_ops = {
205 	.read		= au1xpsc_ac97_read,
206 	.write		= au1xpsc_ac97_write,
207 	.reset		= au1xpsc_ac97_cold_reset,
208 	.warm_reset	= au1xpsc_ac97_warm_reset,
209 };
210 
211 static int au1xpsc_ac97_hw_params(struct snd_pcm_substream *substream,
212 				  struct snd_pcm_hw_params *params,
213 				  struct snd_soc_dai *dai)
214 {
215 	struct au1xpsc_audio_data *pscdata = snd_soc_dai_get_drvdata(dai);
216 	unsigned long r, ro, stat;
217 	int chans, t, stype = substream->stream;
218 
219 	chans = params_channels(params);
220 
221 	r = ro = __raw_readl(AC97_CFG(pscdata));
222 	stat = __raw_readl(AC97_STAT(pscdata));
223 
224 	/* already active? */
225 	if (stat & (PSC_AC97STAT_TB | PSC_AC97STAT_RB)) {
226 		/* reject parameters not currently set up */
227 		if ((PSC_AC97CFG_GET_LEN(r) != params->msbits) ||
228 		    (pscdata->rate != params_rate(params)))
229 			return -EINVAL;
230 	} else {
231 
232 		/* set sample bitdepth: REG[24:21]=(BITS-2)/2 */
233 		r &= ~PSC_AC97CFG_LEN_MASK;
234 		r |= PSC_AC97CFG_SET_LEN(params->msbits);
235 
236 		/* channels: enable slots for front L/R channel */
237 		if (stype == SNDRV_PCM_STREAM_PLAYBACK) {
238 			r &= ~PSC_AC97CFG_TXSLOT_MASK;
239 			r |= PSC_AC97CFG_TXSLOT_ENA(3);
240 			r |= PSC_AC97CFG_TXSLOT_ENA(4);
241 		} else {
242 			r &= ~PSC_AC97CFG_RXSLOT_MASK;
243 			r |= PSC_AC97CFG_RXSLOT_ENA(3);
244 			r |= PSC_AC97CFG_RXSLOT_ENA(4);
245 		}
246 
247 		/* do we need to poke the hardware? */
248 		if (!(r ^ ro))
249 			goto out;
250 
251 		/* ac97 engine is about to be disabled */
252 		mutex_lock(&pscdata->lock);
253 
254 		/* disable AC97 device controller first... */
255 		__raw_writel(r & ~PSC_AC97CFG_DE_ENABLE, AC97_CFG(pscdata));
256 		wmb(); /* drain writebuffer */
257 
258 		/* ...wait for it... */
259 		t = 100;
260 		while ((__raw_readl(AC97_STAT(pscdata)) & PSC_AC97STAT_DR) && --t)
261 			msleep(1);
262 
263 		if (!t)
264 			printk(KERN_ERR "PSC-AC97: can't disable!\n");
265 
266 		/* ...write config... */
267 		__raw_writel(r, AC97_CFG(pscdata));
268 		wmb(); /* drain writebuffer */
269 
270 		/* ...enable the AC97 controller again... */
271 		__raw_writel(r | PSC_AC97CFG_DE_ENABLE, AC97_CFG(pscdata));
272 		wmb(); /* drain writebuffer */
273 
274 		/* ...and wait for ready bit */
275 		t = 100;
276 		while ((!(__raw_readl(AC97_STAT(pscdata)) & PSC_AC97STAT_DR)) && --t)
277 			msleep(1);
278 
279 		if (!t)
280 			printk(KERN_ERR "PSC-AC97: can't enable!\n");
281 
282 		mutex_unlock(&pscdata->lock);
283 
284 		pscdata->cfg = r;
285 		pscdata->rate = params_rate(params);
286 	}
287 
288 out:
289 	return 0;
290 }
291 
292 static int au1xpsc_ac97_trigger(struct snd_pcm_substream *substream,
293 				int cmd, struct snd_soc_dai *dai)
294 {
295 	struct au1xpsc_audio_data *pscdata = snd_soc_dai_get_drvdata(dai);
296 	int ret, stype = substream->stream;
297 
298 	ret = 0;
299 
300 	switch (cmd) {
301 	case SNDRV_PCM_TRIGGER_START:
302 	case SNDRV_PCM_TRIGGER_RESUME:
303 		__raw_writel(AC97PCR_CLRFIFO(stype), AC97_PCR(pscdata));
304 		wmb(); /* drain writebuffer */
305 		__raw_writel(AC97PCR_START(stype), AC97_PCR(pscdata));
306 		wmb(); /* drain writebuffer */
307 		break;
308 	case SNDRV_PCM_TRIGGER_STOP:
309 	case SNDRV_PCM_TRIGGER_SUSPEND:
310 		__raw_writel(AC97PCR_STOP(stype), AC97_PCR(pscdata));
311 		wmb(); /* drain writebuffer */
312 
313 		while (__raw_readl(AC97_STAT(pscdata)) & AC97STAT_BUSY(stype))
314 			asm volatile ("nop");
315 
316 		__raw_writel(AC97PCR_CLRFIFO(stype), AC97_PCR(pscdata));
317 		wmb(); /* drain writebuffer */
318 
319 		break;
320 	default:
321 		ret = -EINVAL;
322 	}
323 	return ret;
324 }
325 
326 static int au1xpsc_ac97_startup(struct snd_pcm_substream *substream,
327 				struct snd_soc_dai *dai)
328 {
329 	struct au1xpsc_audio_data *pscdata = snd_soc_dai_get_drvdata(dai);
330 	snd_soc_dai_set_dma_data(dai, substream, &pscdata->dmaids[0]);
331 	return 0;
332 }
333 
334 static int au1xpsc_ac97_probe(struct snd_soc_dai *dai)
335 {
336 	return au1xpsc_ac97_workdata ? 0 : -ENODEV;
337 }
338 
339 static const struct snd_soc_dai_ops au1xpsc_ac97_dai_ops = {
340 	.startup	= au1xpsc_ac97_startup,
341 	.trigger	= au1xpsc_ac97_trigger,
342 	.hw_params	= au1xpsc_ac97_hw_params,
343 };
344 
345 static const struct snd_soc_dai_driver au1xpsc_ac97_dai_template = {
346 	.bus_control		= true,
347 	.probe			= au1xpsc_ac97_probe,
348 	.playback = {
349 		.rates		= AC97_RATES,
350 		.formats	= AC97_FMTS,
351 		.channels_min	= 2,
352 		.channels_max	= 2,
353 	},
354 	.capture = {
355 		.rates		= AC97_RATES,
356 		.formats	= AC97_FMTS,
357 		.channels_min	= 2,
358 		.channels_max	= 2,
359 	},
360 	.ops = &au1xpsc_ac97_dai_ops,
361 };
362 
363 static const struct snd_soc_component_driver au1xpsc_ac97_component = {
364 	.name		= "au1xpsc-ac97",
365 };
366 
367 static int au1xpsc_ac97_drvprobe(struct platform_device *pdev)
368 {
369 	int ret;
370 	struct resource *iores, *dmares;
371 	unsigned long sel;
372 	struct au1xpsc_audio_data *wd;
373 
374 	wd = devm_kzalloc(&pdev->dev, sizeof(struct au1xpsc_audio_data),
375 			  GFP_KERNEL);
376 	if (!wd)
377 		return -ENOMEM;
378 
379 	mutex_init(&wd->lock);
380 
381 	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
382 	wd->mmio = devm_ioremap_resource(&pdev->dev, iores);
383 	if (IS_ERR(wd->mmio))
384 		return PTR_ERR(wd->mmio);
385 
386 	dmares = platform_get_resource(pdev, IORESOURCE_DMA, 0);
387 	if (!dmares)
388 		return -EBUSY;
389 	wd->dmaids[SNDRV_PCM_STREAM_PLAYBACK] = dmares->start;
390 
391 	dmares = platform_get_resource(pdev, IORESOURCE_DMA, 1);
392 	if (!dmares)
393 		return -EBUSY;
394 	wd->dmaids[SNDRV_PCM_STREAM_CAPTURE] = dmares->start;
395 
396 	/* configuration: max dma trigger threshold, enable ac97 */
397 	wd->cfg = PSC_AC97CFG_RT_FIFO8 | PSC_AC97CFG_TT_FIFO8 |
398 		  PSC_AC97CFG_DE_ENABLE;
399 
400 	/* preserve PSC clock source set up by platform	 */
401 	sel = __raw_readl(PSC_SEL(wd)) & PSC_SEL_CLK_MASK;
402 	__raw_writel(PSC_CTRL_DISABLE, PSC_CTRL(wd));
403 	wmb(); /* drain writebuffer */
404 	__raw_writel(0, PSC_SEL(wd));
405 	wmb(); /* drain writebuffer */
406 	__raw_writel(PSC_SEL_PS_AC97MODE | sel, PSC_SEL(wd));
407 	wmb(); /* drain writebuffer */
408 
409 	/* name the DAI like this device instance ("au1xpsc-ac97.PSCINDEX") */
410 	memcpy(&wd->dai_drv, &au1xpsc_ac97_dai_template,
411 	       sizeof(struct snd_soc_dai_driver));
412 	wd->dai_drv.name = dev_name(&pdev->dev);
413 
414 	platform_set_drvdata(pdev, wd);
415 
416 	ret = snd_soc_set_ac97_ops(&psc_ac97_ops);
417 	if (ret)
418 		return ret;
419 
420 	ret = snd_soc_register_component(&pdev->dev, &au1xpsc_ac97_component,
421 					 &wd->dai_drv, 1);
422 	if (ret)
423 		return ret;
424 
425 	au1xpsc_ac97_workdata = wd;
426 	return 0;
427 }
428 
429 static int au1xpsc_ac97_drvremove(struct platform_device *pdev)
430 {
431 	struct au1xpsc_audio_data *wd = platform_get_drvdata(pdev);
432 
433 	snd_soc_unregister_component(&pdev->dev);
434 
435 	/* disable PSC completely */
436 	__raw_writel(0, AC97_CFG(wd));
437 	wmb(); /* drain writebuffer */
438 	__raw_writel(PSC_CTRL_DISABLE, PSC_CTRL(wd));
439 	wmb(); /* drain writebuffer */
440 
441 	au1xpsc_ac97_workdata = NULL;	/* MDEV */
442 
443 	return 0;
444 }
445 
446 #ifdef CONFIG_PM
447 static int au1xpsc_ac97_drvsuspend(struct device *dev)
448 {
449 	struct au1xpsc_audio_data *wd = dev_get_drvdata(dev);
450 
451 	/* save interesting registers and disable PSC */
452 	wd->pm[0] = __raw_readl(PSC_SEL(wd));
453 
454 	__raw_writel(0, AC97_CFG(wd));
455 	wmb(); /* drain writebuffer */
456 	__raw_writel(PSC_CTRL_DISABLE, PSC_CTRL(wd));
457 	wmb(); /* drain writebuffer */
458 
459 	return 0;
460 }
461 
462 static int au1xpsc_ac97_drvresume(struct device *dev)
463 {
464 	struct au1xpsc_audio_data *wd = dev_get_drvdata(dev);
465 
466 	/* restore PSC clock config */
467 	__raw_writel(wd->pm[0] | PSC_SEL_PS_AC97MODE, PSC_SEL(wd));
468 	wmb(); /* drain writebuffer */
469 
470 	/* after this point the ac97 core will cold-reset the codec.
471 	 * During cold-reset the PSC is reinitialized and the last
472 	 * configuration set up in hw_params() is restored.
473 	 */
474 	return 0;
475 }
476 
477 static const struct dev_pm_ops au1xpscac97_pmops = {
478 	.suspend	= au1xpsc_ac97_drvsuspend,
479 	.resume		= au1xpsc_ac97_drvresume,
480 };
481 
482 #define AU1XPSCAC97_PMOPS &au1xpscac97_pmops
483 
484 #else
485 
486 #define AU1XPSCAC97_PMOPS NULL
487 
488 #endif
489 
490 static struct platform_driver au1xpsc_ac97_driver = {
491 	.driver	= {
492 		.name	= "au1xpsc_ac97",
493 		.pm	= AU1XPSCAC97_PMOPS,
494 	},
495 	.probe		= au1xpsc_ac97_drvprobe,
496 	.remove		= au1xpsc_ac97_drvremove,
497 };
498 
499 module_platform_driver(au1xpsc_ac97_driver);
500 
501 MODULE_LICENSE("GPL");
502 MODULE_DESCRIPTION("Au12x0/Au1550 PSC AC97 ALSA ASoC audio driver");
503 MODULE_AUTHOR("Manuel Lauss");
504 
505