xref: /openbmc/linux/sound/soc/au1x/psc-i2s.c (revision 22d55f02)
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  * Au1xxx-PSC I2S glue.
9  *
10  * NOTE: so far only PSC slave mode (bit- and frameclock) is supported.
11  */
12 
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/slab.h>
16 #include <linux/suspend.h>
17 #include <sound/core.h>
18 #include <sound/pcm.h>
19 #include <sound/initval.h>
20 #include <sound/soc.h>
21 #include <asm/mach-au1x00/au1000.h>
22 #include <asm/mach-au1x00/au1xxx_psc.h>
23 
24 #include "psc.h"
25 
26 /* supported I2S DAI hardware formats */
27 #define AU1XPSC_I2S_DAIFMT \
28 	(SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_LEFT_J |	\
29 	 SND_SOC_DAIFMT_NB_NF)
30 
31 /* supported I2S direction */
32 #define AU1XPSC_I2S_DIR \
33 	(SND_SOC_DAIDIR_PLAYBACK | SND_SOC_DAIDIR_CAPTURE)
34 
35 #define AU1XPSC_I2S_RATES \
36 	SNDRV_PCM_RATE_8000_192000
37 
38 #define AU1XPSC_I2S_FMTS \
39 	(SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_LE)
40 
41 #define I2SSTAT_BUSY(stype)	\
42 	((stype) == SNDRV_PCM_STREAM_PLAYBACK ? PSC_I2SSTAT_TB : PSC_I2SSTAT_RB)
43 #define I2SPCR_START(stype)	\
44 	((stype) == SNDRV_PCM_STREAM_PLAYBACK ? PSC_I2SPCR_TS : PSC_I2SPCR_RS)
45 #define I2SPCR_STOP(stype)	\
46 	((stype) == SNDRV_PCM_STREAM_PLAYBACK ? PSC_I2SPCR_TP : PSC_I2SPCR_RP)
47 #define I2SPCR_CLRFIFO(stype)	\
48 	((stype) == SNDRV_PCM_STREAM_PLAYBACK ? PSC_I2SPCR_TC : PSC_I2SPCR_RC)
49 
50 
51 static int au1xpsc_i2s_set_fmt(struct snd_soc_dai *cpu_dai,
52 			       unsigned int fmt)
53 {
54 	struct au1xpsc_audio_data *pscdata = snd_soc_dai_get_drvdata(cpu_dai);
55 	unsigned long ct;
56 	int ret;
57 
58 	ret = -EINVAL;
59 
60 	ct = pscdata->cfg;
61 
62 	ct &= ~(PSC_I2SCFG_XM | PSC_I2SCFG_MLJ);	/* left-justified */
63 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
64 	case SND_SOC_DAIFMT_I2S:
65 		ct |= PSC_I2SCFG_XM;	/* enable I2S mode */
66 		break;
67 	case SND_SOC_DAIFMT_MSB:
68 		break;
69 	case SND_SOC_DAIFMT_LSB:
70 		ct |= PSC_I2SCFG_MLJ;	/* LSB (right-) justified */
71 		break;
72 	default:
73 		goto out;
74 	}
75 
76 	ct &= ~(PSC_I2SCFG_BI | PSC_I2SCFG_WI);		/* IB-IF */
77 	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
78 	case SND_SOC_DAIFMT_NB_NF:
79 		ct |= PSC_I2SCFG_BI | PSC_I2SCFG_WI;
80 		break;
81 	case SND_SOC_DAIFMT_NB_IF:
82 		ct |= PSC_I2SCFG_BI;
83 		break;
84 	case SND_SOC_DAIFMT_IB_NF:
85 		ct |= PSC_I2SCFG_WI;
86 		break;
87 	case SND_SOC_DAIFMT_IB_IF:
88 		break;
89 	default:
90 		goto out;
91 	}
92 
93 	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
94 	case SND_SOC_DAIFMT_CBM_CFM:	/* CODEC master */
95 		ct |= PSC_I2SCFG_MS;	/* PSC I2S slave mode */
96 		break;
97 	case SND_SOC_DAIFMT_CBS_CFS:	/* CODEC slave */
98 		ct &= ~PSC_I2SCFG_MS;	/* PSC I2S Master mode */
99 		break;
100 	default:
101 		goto out;
102 	}
103 
104 	pscdata->cfg = ct;
105 	ret = 0;
106 out:
107 	return ret;
108 }
109 
110 static int au1xpsc_i2s_hw_params(struct snd_pcm_substream *substream,
111 				 struct snd_pcm_hw_params *params,
112 				 struct snd_soc_dai *dai)
113 {
114 	struct au1xpsc_audio_data *pscdata = snd_soc_dai_get_drvdata(dai);
115 
116 	int cfgbits;
117 	unsigned long stat;
118 
119 	/* check if the PSC is already streaming data */
120 	stat = __raw_readl(I2S_STAT(pscdata));
121 	if (stat & (PSC_I2SSTAT_TB | PSC_I2SSTAT_RB)) {
122 		/* reject parameters not currently set up in hardware */
123 		cfgbits = __raw_readl(I2S_CFG(pscdata));
124 		if ((PSC_I2SCFG_GET_LEN(cfgbits) != params->msbits) ||
125 		    (params_rate(params) != pscdata->rate))
126 			return -EINVAL;
127 	} else {
128 		/* set sample bitdepth */
129 		pscdata->cfg &= ~(0x1f << 4);
130 		pscdata->cfg |= PSC_I2SCFG_SET_LEN(params->msbits);
131 		/* remember current rate for other stream */
132 		pscdata->rate = params_rate(params);
133 	}
134 	return 0;
135 }
136 
137 /* Configure PSC late:  on my devel systems the codec  is I2S master and
138  * supplies the i2sbitclock __AND__ i2sMclk (!) to the PSC unit.  ASoC
139  * uses aggressive PM and  switches the codec off  when it is not in use
140  * which also means the PSC unit doesn't get any clocks and is therefore
141  * dead. That's why this chunk here gets called from the trigger callback
142  * because I can be reasonably certain the codec is driving the clocks.
143  */
144 static int au1xpsc_i2s_configure(struct au1xpsc_audio_data *pscdata)
145 {
146 	unsigned long tmo;
147 
148 	/* bring PSC out of sleep, and configure I2S unit */
149 	__raw_writel(PSC_CTRL_ENABLE, PSC_CTRL(pscdata));
150 	wmb(); /* drain writebuffer */
151 
152 	tmo = 1000000;
153 	while (!(__raw_readl(I2S_STAT(pscdata)) & PSC_I2SSTAT_SR) && tmo)
154 		tmo--;
155 
156 	if (!tmo)
157 		goto psc_err;
158 
159 	__raw_writel(0, I2S_CFG(pscdata));
160 	wmb(); /* drain writebuffer */
161 	__raw_writel(pscdata->cfg | PSC_I2SCFG_DE_ENABLE, I2S_CFG(pscdata));
162 	wmb(); /* drain writebuffer */
163 
164 	/* wait for I2S controller to become ready */
165 	tmo = 1000000;
166 	while (!(__raw_readl(I2S_STAT(pscdata)) & PSC_I2SSTAT_DR) && tmo)
167 		tmo--;
168 
169 	if (tmo)
170 		return 0;
171 
172 psc_err:
173 	__raw_writel(0, I2S_CFG(pscdata));
174 	__raw_writel(PSC_CTRL_SUSPEND, PSC_CTRL(pscdata));
175 	wmb(); /* drain writebuffer */
176 	return -ETIMEDOUT;
177 }
178 
179 static int au1xpsc_i2s_start(struct au1xpsc_audio_data *pscdata, int stype)
180 {
181 	unsigned long tmo, stat;
182 	int ret;
183 
184 	ret = 0;
185 
186 	/* if both TX and RX are idle, configure the PSC  */
187 	stat = __raw_readl(I2S_STAT(pscdata));
188 	if (!(stat & (PSC_I2SSTAT_TB | PSC_I2SSTAT_RB))) {
189 		ret = au1xpsc_i2s_configure(pscdata);
190 		if (ret)
191 			goto out;
192 	}
193 
194 	__raw_writel(I2SPCR_CLRFIFO(stype), I2S_PCR(pscdata));
195 	wmb(); /* drain writebuffer */
196 	__raw_writel(I2SPCR_START(stype), I2S_PCR(pscdata));
197 	wmb(); /* drain writebuffer */
198 
199 	/* wait for start confirmation */
200 	tmo = 1000000;
201 	while (!(__raw_readl(I2S_STAT(pscdata)) & I2SSTAT_BUSY(stype)) && tmo)
202 		tmo--;
203 
204 	if (!tmo) {
205 		__raw_writel(I2SPCR_STOP(stype), I2S_PCR(pscdata));
206 		wmb(); /* drain writebuffer */
207 		ret = -ETIMEDOUT;
208 	}
209 out:
210 	return ret;
211 }
212 
213 static int au1xpsc_i2s_stop(struct au1xpsc_audio_data *pscdata, int stype)
214 {
215 	unsigned long tmo, stat;
216 
217 	__raw_writel(I2SPCR_STOP(stype), I2S_PCR(pscdata));
218 	wmb(); /* drain writebuffer */
219 
220 	/* wait for stop confirmation */
221 	tmo = 1000000;
222 	while ((__raw_readl(I2S_STAT(pscdata)) & I2SSTAT_BUSY(stype)) && tmo)
223 		tmo--;
224 
225 	/* if both TX and RX are idle, disable PSC */
226 	stat = __raw_readl(I2S_STAT(pscdata));
227 	if (!(stat & (PSC_I2SSTAT_TB | PSC_I2SSTAT_RB))) {
228 		__raw_writel(0, I2S_CFG(pscdata));
229 		wmb(); /* drain writebuffer */
230 		__raw_writel(PSC_CTRL_SUSPEND, PSC_CTRL(pscdata));
231 		wmb(); /* drain writebuffer */
232 	}
233 	return 0;
234 }
235 
236 static int au1xpsc_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
237 			       struct snd_soc_dai *dai)
238 {
239 	struct au1xpsc_audio_data *pscdata = snd_soc_dai_get_drvdata(dai);
240 	int ret, stype = substream->stream;
241 
242 	switch (cmd) {
243 	case SNDRV_PCM_TRIGGER_START:
244 	case SNDRV_PCM_TRIGGER_RESUME:
245 		ret = au1xpsc_i2s_start(pscdata, stype);
246 		break;
247 	case SNDRV_PCM_TRIGGER_STOP:
248 	case SNDRV_PCM_TRIGGER_SUSPEND:
249 		ret = au1xpsc_i2s_stop(pscdata, stype);
250 		break;
251 	default:
252 		ret = -EINVAL;
253 	}
254 	return ret;
255 }
256 
257 static int au1xpsc_i2s_startup(struct snd_pcm_substream *substream,
258 			       struct snd_soc_dai *dai)
259 {
260 	struct au1xpsc_audio_data *pscdata = snd_soc_dai_get_drvdata(dai);
261 	snd_soc_dai_set_dma_data(dai, substream, &pscdata->dmaids[0]);
262 	return 0;
263 }
264 
265 static const struct snd_soc_dai_ops au1xpsc_i2s_dai_ops = {
266 	.startup	= au1xpsc_i2s_startup,
267 	.trigger	= au1xpsc_i2s_trigger,
268 	.hw_params	= au1xpsc_i2s_hw_params,
269 	.set_fmt	= au1xpsc_i2s_set_fmt,
270 };
271 
272 static const struct snd_soc_dai_driver au1xpsc_i2s_dai_template = {
273 	.playback = {
274 		.rates		= AU1XPSC_I2S_RATES,
275 		.formats	= AU1XPSC_I2S_FMTS,
276 		.channels_min	= 2,
277 		.channels_max	= 8,	/* 2 without external help */
278 	},
279 	.capture = {
280 		.rates		= AU1XPSC_I2S_RATES,
281 		.formats	= AU1XPSC_I2S_FMTS,
282 		.channels_min	= 2,
283 		.channels_max	= 8,	/* 2 without external help */
284 	},
285 	.ops = &au1xpsc_i2s_dai_ops,
286 };
287 
288 static const struct snd_soc_component_driver au1xpsc_i2s_component = {
289 	.name		= "au1xpsc-i2s",
290 };
291 
292 static int au1xpsc_i2s_drvprobe(struct platform_device *pdev)
293 {
294 	struct resource *iores, *dmares;
295 	unsigned long sel;
296 	struct au1xpsc_audio_data *wd;
297 
298 	wd = devm_kzalloc(&pdev->dev, sizeof(struct au1xpsc_audio_data),
299 			  GFP_KERNEL);
300 	if (!wd)
301 		return -ENOMEM;
302 
303 	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
304 	wd->mmio = devm_ioremap_resource(&pdev->dev, iores);
305 	if (IS_ERR(wd->mmio))
306 		return PTR_ERR(wd->mmio);
307 
308 	dmares = platform_get_resource(pdev, IORESOURCE_DMA, 0);
309 	if (!dmares)
310 		return -EBUSY;
311 	wd->dmaids[SNDRV_PCM_STREAM_PLAYBACK] = dmares->start;
312 
313 	dmares = platform_get_resource(pdev, IORESOURCE_DMA, 1);
314 	if (!dmares)
315 		return -EBUSY;
316 	wd->dmaids[SNDRV_PCM_STREAM_CAPTURE] = dmares->start;
317 
318 	/* preserve PSC clock source set up by platform (dev.platform_data
319 	 * is already occupied by soc layer)
320 	 */
321 	sel = __raw_readl(PSC_SEL(wd)) & PSC_SEL_CLK_MASK;
322 	__raw_writel(PSC_CTRL_DISABLE, PSC_CTRL(wd));
323 	wmb(); /* drain writebuffer */
324 	__raw_writel(PSC_SEL_PS_I2SMODE | sel, PSC_SEL(wd));
325 	__raw_writel(0, I2S_CFG(wd));
326 	wmb(); /* drain writebuffer */
327 
328 	/* preconfigure: set max rx/tx fifo depths */
329 	wd->cfg |= PSC_I2SCFG_RT_FIFO8 | PSC_I2SCFG_TT_FIFO8;
330 
331 	/* don't wait for I2S core to become ready now; clocks may not
332 	 * be running yet; depending on clock input for PSC a wait might
333 	 * time out.
334 	 */
335 
336 	/* name the DAI like this device instance ("au1xpsc-i2s.PSCINDEX") */
337 	memcpy(&wd->dai_drv, &au1xpsc_i2s_dai_template,
338 	       sizeof(struct snd_soc_dai_driver));
339 	wd->dai_drv.name = dev_name(&pdev->dev);
340 
341 	platform_set_drvdata(pdev, wd);
342 
343 	return snd_soc_register_component(&pdev->dev, &au1xpsc_i2s_component,
344 					  &wd->dai_drv, 1);
345 }
346 
347 static int au1xpsc_i2s_drvremove(struct platform_device *pdev)
348 {
349 	struct au1xpsc_audio_data *wd = platform_get_drvdata(pdev);
350 
351 	snd_soc_unregister_component(&pdev->dev);
352 
353 	__raw_writel(0, I2S_CFG(wd));
354 	wmb(); /* drain writebuffer */
355 	__raw_writel(PSC_CTRL_DISABLE, PSC_CTRL(wd));
356 	wmb(); /* drain writebuffer */
357 
358 	return 0;
359 }
360 
361 #ifdef CONFIG_PM
362 static int au1xpsc_i2s_drvsuspend(struct device *dev)
363 {
364 	struct au1xpsc_audio_data *wd = dev_get_drvdata(dev);
365 
366 	/* save interesting register and disable PSC */
367 	wd->pm[0] = __raw_readl(PSC_SEL(wd));
368 
369 	__raw_writel(0, I2S_CFG(wd));
370 	wmb(); /* drain writebuffer */
371 	__raw_writel(PSC_CTRL_DISABLE, PSC_CTRL(wd));
372 	wmb(); /* drain writebuffer */
373 
374 	return 0;
375 }
376 
377 static int au1xpsc_i2s_drvresume(struct device *dev)
378 {
379 	struct au1xpsc_audio_data *wd = dev_get_drvdata(dev);
380 
381 	/* select I2S mode and PSC clock */
382 	__raw_writel(PSC_CTRL_DISABLE, PSC_CTRL(wd));
383 	wmb(); /* drain writebuffer */
384 	__raw_writel(0, PSC_SEL(wd));
385 	wmb(); /* drain writebuffer */
386 	__raw_writel(wd->pm[0], PSC_SEL(wd));
387 	wmb(); /* drain writebuffer */
388 
389 	return 0;
390 }
391 
392 static const struct dev_pm_ops au1xpsci2s_pmops = {
393 	.suspend	= au1xpsc_i2s_drvsuspend,
394 	.resume		= au1xpsc_i2s_drvresume,
395 };
396 
397 #define AU1XPSCI2S_PMOPS &au1xpsci2s_pmops
398 
399 #else
400 
401 #define AU1XPSCI2S_PMOPS NULL
402 
403 #endif
404 
405 static struct platform_driver au1xpsc_i2s_driver = {
406 	.driver		= {
407 		.name	= "au1xpsc_i2s",
408 		.pm	= AU1XPSCI2S_PMOPS,
409 	},
410 	.probe		= au1xpsc_i2s_drvprobe,
411 	.remove		= au1xpsc_i2s_drvremove,
412 };
413 
414 module_platform_driver(au1xpsc_i2s_driver);
415 
416 MODULE_LICENSE("GPL");
417 MODULE_DESCRIPTION("Au12x0/Au1550 PSC I2S ALSA ASoC audio driver");
418 MODULE_AUTHOR("Manuel Lauss");
419