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!!!! */
54static 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 */
62static 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 */
75static 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 */
116static 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 */
148static 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
159static 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 */
204static 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
211static 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
288out:
289	return 0;
290}
291
292static 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
326static 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
334static int au1xpsc_ac97_probe(struct snd_soc_dai *dai)
335{
336	return au1xpsc_ac97_workdata ? 0 : -ENODEV;
337}
338
339static 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
345static 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
363static const struct snd_soc_component_driver au1xpsc_ac97_component = {
364	.name		= "au1xpsc-ac97",
365};
366
367static 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
429static 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
447static 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
462static 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
477static 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
490static 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
499module_platform_driver(au1xpsc_ac97_driver);
500
501MODULE_LICENSE("GPL");
502MODULE_DESCRIPTION("Au12x0/Au1550 PSC AC97 ALSA ASoC audio driver");
503MODULE_AUTHOR("Manuel Lauss");
504
505