xref: /openbmc/linux/sound/soc/au1x/psc-ac97.c (revision 55fd7e02)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Au12x0/Au1550 PSC ALSA ASoC audio support.
4  *
5  * (c) 2007-2009 MSC Vertriebsges.m.b.H.,
6  *	Manuel Lauss <manuel.lauss@gmail.com>
7  *
8  * Au1xxx-PSC AC97 glue.
9  */
10 
11 #include <linux/init.h>
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/device.h>
15 #include <linux/delay.h>
16 #include <linux/mutex.h>
17 #include <linux/suspend.h>
18 #include <sound/core.h>
19 #include <sound/pcm.h>
20 #include <sound/initval.h>
21 #include <sound/soc.h>
22 #include <asm/mach-au1x00/au1000.h>
23 #include <asm/mach-au1x00/au1xxx_psc.h>
24 
25 #include "psc.h"
26 
27 /* how often to retry failed codec register reads/writes */
28 #define AC97_RW_RETRIES	5
29 
30 #define AC97_DIR	\
31 	(SND_SOC_DAIDIR_PLAYBACK | SND_SOC_DAIDIR_CAPTURE)
32 
33 #define AC97_RATES	\
34 	SNDRV_PCM_RATE_8000_48000
35 
36 #define AC97_FMTS	\
37 	(SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S20_3BE)
38 
39 #define AC97PCR_START(stype)	\
40 	((stype) == SNDRV_PCM_STREAM_PLAYBACK ? PSC_AC97PCR_TS : PSC_AC97PCR_RS)
41 #define AC97PCR_STOP(stype)	\
42 	((stype) == SNDRV_PCM_STREAM_PLAYBACK ? PSC_AC97PCR_TP : PSC_AC97PCR_RP)
43 #define AC97PCR_CLRFIFO(stype)	\
44 	((stype) == SNDRV_PCM_STREAM_PLAYBACK ? PSC_AC97PCR_TC : PSC_AC97PCR_RC)
45 
46 #define AC97STAT_BUSY(stype)	\
47 	((stype) == SNDRV_PCM_STREAM_PLAYBACK ? PSC_AC97STAT_TB : PSC_AC97STAT_RB)
48 
49 /* instance data. There can be only one, MacLeod!!!! */
50 static struct au1xpsc_audio_data *au1xpsc_ac97_workdata;
51 
52 #if 0
53 
54 /* this could theoretically work, but ac97->bus->card->private_data can be NULL
55  * when snd_ac97_mixer() is called; I don't know if the rest further down the
56  * chain are always valid either.
57  */
58 static inline struct au1xpsc_audio_data *ac97_to_pscdata(struct snd_ac97 *x)
59 {
60 	struct snd_soc_card *c = x->bus->card->private_data;
61 	return snd_soc_dai_get_drvdata(c->asoc_rtd_to_cpu(rtd, 0));
62 }
63 
64 #else
65 
66 #define ac97_to_pscdata(x)	au1xpsc_ac97_workdata
67 
68 #endif
69 
70 /* AC97 controller reads codec register */
71 static unsigned short au1xpsc_ac97_read(struct snd_ac97 *ac97,
72 					unsigned short reg)
73 {
74 	struct au1xpsc_audio_data *pscdata = ac97_to_pscdata(ac97);
75 	unsigned short retry, tmo;
76 	unsigned long data;
77 
78 	__raw_writel(PSC_AC97EVNT_CD, AC97_EVNT(pscdata));
79 	wmb(); /* drain writebuffer */
80 
81 	retry = AC97_RW_RETRIES;
82 	do {
83 		mutex_lock(&pscdata->lock);
84 
85 		__raw_writel(PSC_AC97CDC_RD | PSC_AC97CDC_INDX(reg),
86 			  AC97_CDC(pscdata));
87 		wmb(); /* drain writebuffer */
88 
89 		tmo = 20;
90 		do {
91 			udelay(21);
92 			if (__raw_readl(AC97_EVNT(pscdata)) & PSC_AC97EVNT_CD)
93 				break;
94 		} while (--tmo);
95 
96 		data = __raw_readl(AC97_CDC(pscdata));
97 
98 		__raw_writel(PSC_AC97EVNT_CD, AC97_EVNT(pscdata));
99 		wmb(); /* drain writebuffer */
100 
101 		mutex_unlock(&pscdata->lock);
102 
103 		if (reg != ((data >> 16) & 0x7f))
104 			tmo = 1;	/* wrong register, try again */
105 
106 	} while (--retry && !tmo);
107 
108 	return retry ? data & 0xffff : 0xffff;
109 }
110 
111 /* AC97 controller writes to codec register */
112 static void au1xpsc_ac97_write(struct snd_ac97 *ac97, unsigned short reg,
113 				unsigned short val)
114 {
115 	struct au1xpsc_audio_data *pscdata = ac97_to_pscdata(ac97);
116 	unsigned int tmo, retry;
117 
118 	__raw_writel(PSC_AC97EVNT_CD, AC97_EVNT(pscdata));
119 	wmb(); /* drain writebuffer */
120 
121 	retry = AC97_RW_RETRIES;
122 	do {
123 		mutex_lock(&pscdata->lock);
124 
125 		__raw_writel(PSC_AC97CDC_INDX(reg) | (val & 0xffff),
126 			  AC97_CDC(pscdata));
127 		wmb(); /* drain writebuffer */
128 
129 		tmo = 20;
130 		do {
131 			udelay(21);
132 			if (__raw_readl(AC97_EVNT(pscdata)) & PSC_AC97EVNT_CD)
133 				break;
134 		} while (--tmo);
135 
136 		__raw_writel(PSC_AC97EVNT_CD, AC97_EVNT(pscdata));
137 		wmb(); /* drain writebuffer */
138 
139 		mutex_unlock(&pscdata->lock);
140 	} while (--retry && !tmo);
141 }
142 
143 /* AC97 controller asserts a warm reset */
144 static void au1xpsc_ac97_warm_reset(struct snd_ac97 *ac97)
145 {
146 	struct au1xpsc_audio_data *pscdata = ac97_to_pscdata(ac97);
147 
148 	__raw_writel(PSC_AC97RST_SNC, AC97_RST(pscdata));
149 	wmb(); /* drain writebuffer */
150 	msleep(10);
151 	__raw_writel(0, AC97_RST(pscdata));
152 	wmb(); /* drain writebuffer */
153 }
154 
155 static void au1xpsc_ac97_cold_reset(struct snd_ac97 *ac97)
156 {
157 	struct au1xpsc_audio_data *pscdata = ac97_to_pscdata(ac97);
158 	int i;
159 
160 	/* disable PSC during cold reset */
161 	__raw_writel(0, AC97_CFG(au1xpsc_ac97_workdata));
162 	wmb(); /* drain writebuffer */
163 	__raw_writel(PSC_CTRL_DISABLE, PSC_CTRL(pscdata));
164 	wmb(); /* drain writebuffer */
165 
166 	/* issue cold reset */
167 	__raw_writel(PSC_AC97RST_RST, AC97_RST(pscdata));
168 	wmb(); /* drain writebuffer */
169 	msleep(500);
170 	__raw_writel(0, AC97_RST(pscdata));
171 	wmb(); /* drain writebuffer */
172 
173 	/* enable PSC */
174 	__raw_writel(PSC_CTRL_ENABLE, PSC_CTRL(pscdata));
175 	wmb(); /* drain writebuffer */
176 
177 	/* wait for PSC to indicate it's ready */
178 	i = 1000;
179 	while (!((__raw_readl(AC97_STAT(pscdata)) & PSC_AC97STAT_SR)) && (--i))
180 		msleep(1);
181 
182 	if (i == 0) {
183 		printk(KERN_ERR "au1xpsc-ac97: PSC not ready!\n");
184 		return;
185 	}
186 
187 	/* enable the ac97 function */
188 	__raw_writel(pscdata->cfg | PSC_AC97CFG_DE_ENABLE, AC97_CFG(pscdata));
189 	wmb(); /* drain writebuffer */
190 
191 	/* wait for AC97 core to become ready */
192 	i = 1000;
193 	while (!((__raw_readl(AC97_STAT(pscdata)) & PSC_AC97STAT_DR)) && (--i))
194 		msleep(1);
195 	if (i == 0)
196 		printk(KERN_ERR "au1xpsc-ac97: AC97 ctrl not ready\n");
197 }
198 
199 /* AC97 controller operations */
200 static struct snd_ac97_bus_ops psc_ac97_ops = {
201 	.read		= au1xpsc_ac97_read,
202 	.write		= au1xpsc_ac97_write,
203 	.reset		= au1xpsc_ac97_cold_reset,
204 	.warm_reset	= au1xpsc_ac97_warm_reset,
205 };
206 
207 static int au1xpsc_ac97_hw_params(struct snd_pcm_substream *substream,
208 				  struct snd_pcm_hw_params *params,
209 				  struct snd_soc_dai *dai)
210 {
211 	struct au1xpsc_audio_data *pscdata = snd_soc_dai_get_drvdata(dai);
212 	unsigned long r, ro, stat;
213 	int chans, t, stype = substream->stream;
214 
215 	chans = params_channels(params);
216 
217 	r = ro = __raw_readl(AC97_CFG(pscdata));
218 	stat = __raw_readl(AC97_STAT(pscdata));
219 
220 	/* already active? */
221 	if (stat & (PSC_AC97STAT_TB | PSC_AC97STAT_RB)) {
222 		/* reject parameters not currently set up */
223 		if ((PSC_AC97CFG_GET_LEN(r) != params->msbits) ||
224 		    (pscdata->rate != params_rate(params)))
225 			return -EINVAL;
226 	} else {
227 
228 		/* set sample bitdepth: REG[24:21]=(BITS-2)/2 */
229 		r &= ~PSC_AC97CFG_LEN_MASK;
230 		r |= PSC_AC97CFG_SET_LEN(params->msbits);
231 
232 		/* channels: enable slots for front L/R channel */
233 		if (stype == SNDRV_PCM_STREAM_PLAYBACK) {
234 			r &= ~PSC_AC97CFG_TXSLOT_MASK;
235 			r |= PSC_AC97CFG_TXSLOT_ENA(3);
236 			r |= PSC_AC97CFG_TXSLOT_ENA(4);
237 		} else {
238 			r &= ~PSC_AC97CFG_RXSLOT_MASK;
239 			r |= PSC_AC97CFG_RXSLOT_ENA(3);
240 			r |= PSC_AC97CFG_RXSLOT_ENA(4);
241 		}
242 
243 		/* do we need to poke the hardware? */
244 		if (!(r ^ ro))
245 			goto out;
246 
247 		/* ac97 engine is about to be disabled */
248 		mutex_lock(&pscdata->lock);
249 
250 		/* disable AC97 device controller first... */
251 		__raw_writel(r & ~PSC_AC97CFG_DE_ENABLE, AC97_CFG(pscdata));
252 		wmb(); /* drain writebuffer */
253 
254 		/* ...wait for it... */
255 		t = 100;
256 		while ((__raw_readl(AC97_STAT(pscdata)) & PSC_AC97STAT_DR) && --t)
257 			msleep(1);
258 
259 		if (!t)
260 			printk(KERN_ERR "PSC-AC97: can't disable!\n");
261 
262 		/* ...write config... */
263 		__raw_writel(r, AC97_CFG(pscdata));
264 		wmb(); /* drain writebuffer */
265 
266 		/* ...enable the AC97 controller again... */
267 		__raw_writel(r | PSC_AC97CFG_DE_ENABLE, AC97_CFG(pscdata));
268 		wmb(); /* drain writebuffer */
269 
270 		/* ...and wait for ready bit */
271 		t = 100;
272 		while ((!(__raw_readl(AC97_STAT(pscdata)) & PSC_AC97STAT_DR)) && --t)
273 			msleep(1);
274 
275 		if (!t)
276 			printk(KERN_ERR "PSC-AC97: can't enable!\n");
277 
278 		mutex_unlock(&pscdata->lock);
279 
280 		pscdata->cfg = r;
281 		pscdata->rate = params_rate(params);
282 	}
283 
284 out:
285 	return 0;
286 }
287 
288 static int au1xpsc_ac97_trigger(struct snd_pcm_substream *substream,
289 				int cmd, struct snd_soc_dai *dai)
290 {
291 	struct au1xpsc_audio_data *pscdata = snd_soc_dai_get_drvdata(dai);
292 	int ret, stype = substream->stream;
293 
294 	ret = 0;
295 
296 	switch (cmd) {
297 	case SNDRV_PCM_TRIGGER_START:
298 	case SNDRV_PCM_TRIGGER_RESUME:
299 		__raw_writel(AC97PCR_CLRFIFO(stype), AC97_PCR(pscdata));
300 		wmb(); /* drain writebuffer */
301 		__raw_writel(AC97PCR_START(stype), AC97_PCR(pscdata));
302 		wmb(); /* drain writebuffer */
303 		break;
304 	case SNDRV_PCM_TRIGGER_STOP:
305 	case SNDRV_PCM_TRIGGER_SUSPEND:
306 		__raw_writel(AC97PCR_STOP(stype), AC97_PCR(pscdata));
307 		wmb(); /* drain writebuffer */
308 
309 		while (__raw_readl(AC97_STAT(pscdata)) & AC97STAT_BUSY(stype))
310 			asm volatile ("nop");
311 
312 		__raw_writel(AC97PCR_CLRFIFO(stype), AC97_PCR(pscdata));
313 		wmb(); /* drain writebuffer */
314 
315 		break;
316 	default:
317 		ret = -EINVAL;
318 	}
319 	return ret;
320 }
321 
322 static int au1xpsc_ac97_startup(struct snd_pcm_substream *substream,
323 				struct snd_soc_dai *dai)
324 {
325 	struct au1xpsc_audio_data *pscdata = snd_soc_dai_get_drvdata(dai);
326 	snd_soc_dai_set_dma_data(dai, substream, &pscdata->dmaids[0]);
327 	return 0;
328 }
329 
330 static int au1xpsc_ac97_probe(struct snd_soc_dai *dai)
331 {
332 	return au1xpsc_ac97_workdata ? 0 : -ENODEV;
333 }
334 
335 static const struct snd_soc_dai_ops au1xpsc_ac97_dai_ops = {
336 	.startup	= au1xpsc_ac97_startup,
337 	.trigger	= au1xpsc_ac97_trigger,
338 	.hw_params	= au1xpsc_ac97_hw_params,
339 };
340 
341 static const struct snd_soc_dai_driver au1xpsc_ac97_dai_template = {
342 	.probe			= au1xpsc_ac97_probe,
343 	.playback = {
344 		.rates		= AC97_RATES,
345 		.formats	= AC97_FMTS,
346 		.channels_min	= 2,
347 		.channels_max	= 2,
348 	},
349 	.capture = {
350 		.rates		= AC97_RATES,
351 		.formats	= AC97_FMTS,
352 		.channels_min	= 2,
353 		.channels_max	= 2,
354 	},
355 	.ops = &au1xpsc_ac97_dai_ops,
356 };
357 
358 static const struct snd_soc_component_driver au1xpsc_ac97_component = {
359 	.name		= "au1xpsc-ac97",
360 };
361 
362 static int au1xpsc_ac97_drvprobe(struct platform_device *pdev)
363 {
364 	int ret;
365 	struct resource *dmares;
366 	unsigned long sel;
367 	struct au1xpsc_audio_data *wd;
368 
369 	wd = devm_kzalloc(&pdev->dev, sizeof(struct au1xpsc_audio_data),
370 			  GFP_KERNEL);
371 	if (!wd)
372 		return -ENOMEM;
373 
374 	mutex_init(&wd->lock);
375 
376 	wd->mmio = devm_platform_ioremap_resource(pdev, 0);
377 	if (IS_ERR(wd->mmio))
378 		return PTR_ERR(wd->mmio);
379 
380 	dmares = platform_get_resource(pdev, IORESOURCE_DMA, 0);
381 	if (!dmares)
382 		return -EBUSY;
383 	wd->dmaids[SNDRV_PCM_STREAM_PLAYBACK] = dmares->start;
384 
385 	dmares = platform_get_resource(pdev, IORESOURCE_DMA, 1);
386 	if (!dmares)
387 		return -EBUSY;
388 	wd->dmaids[SNDRV_PCM_STREAM_CAPTURE] = dmares->start;
389 
390 	/* configuration: max dma trigger threshold, enable ac97 */
391 	wd->cfg = PSC_AC97CFG_RT_FIFO8 | PSC_AC97CFG_TT_FIFO8 |
392 		  PSC_AC97CFG_DE_ENABLE;
393 
394 	/* preserve PSC clock source set up by platform	 */
395 	sel = __raw_readl(PSC_SEL(wd)) & PSC_SEL_CLK_MASK;
396 	__raw_writel(PSC_CTRL_DISABLE, PSC_CTRL(wd));
397 	wmb(); /* drain writebuffer */
398 	__raw_writel(0, PSC_SEL(wd));
399 	wmb(); /* drain writebuffer */
400 	__raw_writel(PSC_SEL_PS_AC97MODE | sel, PSC_SEL(wd));
401 	wmb(); /* drain writebuffer */
402 
403 	/* name the DAI like this device instance ("au1xpsc-ac97.PSCINDEX") */
404 	memcpy(&wd->dai_drv, &au1xpsc_ac97_dai_template,
405 	       sizeof(struct snd_soc_dai_driver));
406 	wd->dai_drv.name = dev_name(&pdev->dev);
407 
408 	platform_set_drvdata(pdev, wd);
409 
410 	ret = snd_soc_set_ac97_ops(&psc_ac97_ops);
411 	if (ret)
412 		return ret;
413 
414 	ret = snd_soc_register_component(&pdev->dev, &au1xpsc_ac97_component,
415 					 &wd->dai_drv, 1);
416 	if (ret)
417 		return ret;
418 
419 	au1xpsc_ac97_workdata = wd;
420 	return 0;
421 }
422 
423 static int au1xpsc_ac97_drvremove(struct platform_device *pdev)
424 {
425 	struct au1xpsc_audio_data *wd = platform_get_drvdata(pdev);
426 
427 	snd_soc_unregister_component(&pdev->dev);
428 
429 	/* disable PSC completely */
430 	__raw_writel(0, AC97_CFG(wd));
431 	wmb(); /* drain writebuffer */
432 	__raw_writel(PSC_CTRL_DISABLE, PSC_CTRL(wd));
433 	wmb(); /* drain writebuffer */
434 
435 	au1xpsc_ac97_workdata = NULL;	/* MDEV */
436 
437 	return 0;
438 }
439 
440 #ifdef CONFIG_PM
441 static int au1xpsc_ac97_drvsuspend(struct device *dev)
442 {
443 	struct au1xpsc_audio_data *wd = dev_get_drvdata(dev);
444 
445 	/* save interesting registers and disable PSC */
446 	wd->pm[0] = __raw_readl(PSC_SEL(wd));
447 
448 	__raw_writel(0, AC97_CFG(wd));
449 	wmb(); /* drain writebuffer */
450 	__raw_writel(PSC_CTRL_DISABLE, PSC_CTRL(wd));
451 	wmb(); /* drain writebuffer */
452 
453 	return 0;
454 }
455 
456 static int au1xpsc_ac97_drvresume(struct device *dev)
457 {
458 	struct au1xpsc_audio_data *wd = dev_get_drvdata(dev);
459 
460 	/* restore PSC clock config */
461 	__raw_writel(wd->pm[0] | PSC_SEL_PS_AC97MODE, PSC_SEL(wd));
462 	wmb(); /* drain writebuffer */
463 
464 	/* after this point the ac97 core will cold-reset the codec.
465 	 * During cold-reset the PSC is reinitialized and the last
466 	 * configuration set up in hw_params() is restored.
467 	 */
468 	return 0;
469 }
470 
471 static const struct dev_pm_ops au1xpscac97_pmops = {
472 	.suspend	= au1xpsc_ac97_drvsuspend,
473 	.resume		= au1xpsc_ac97_drvresume,
474 };
475 
476 #define AU1XPSCAC97_PMOPS &au1xpscac97_pmops
477 
478 #else
479 
480 #define AU1XPSCAC97_PMOPS NULL
481 
482 #endif
483 
484 static struct platform_driver au1xpsc_ac97_driver = {
485 	.driver	= {
486 		.name	= "au1xpsc_ac97",
487 		.pm	= AU1XPSCAC97_PMOPS,
488 	},
489 	.probe		= au1xpsc_ac97_drvprobe,
490 	.remove		= au1xpsc_ac97_drvremove,
491 };
492 
493 module_platform_driver(au1xpsc_ac97_driver);
494 
495 MODULE_LICENSE("GPL");
496 MODULE_DESCRIPTION("Au12x0/Au1550 PSC AC97 ALSA ASoC audio driver");
497 MODULE_AUTHOR("Manuel Lauss");
498 
499