1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * ASoC driver for Cirrus Logic EP93xx AC97 controller.
4 *
5 * Copyright (c) 2010 Mika Westerberg
6 *
7 * Based on s3c-ac97 ASoC driver by Jaswinder Singh.
8 */
9
10 #include <linux/delay.h>
11 #include <linux/err.h>
12 #include <linux/io.h>
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/platform_device.h>
16 #include <linux/slab.h>
17
18 #include <sound/core.h>
19 #include <sound/dmaengine_pcm.h>
20 #include <sound/ac97_codec.h>
21 #include <sound/soc.h>
22
23 #include <linux/platform_data/dma-ep93xx.h>
24 #include <linux/soc/cirrus/ep93xx.h>
25
26 #include "ep93xx-pcm.h"
27
28 /*
29 * Per channel (1-4) registers.
30 */
31 #define AC97CH(n) (((n) - 1) * 0x20)
32
33 #define AC97DR(n) (AC97CH(n) + 0x0000)
34
35 #define AC97RXCR(n) (AC97CH(n) + 0x0004)
36 #define AC97RXCR_REN BIT(0)
37 #define AC97RXCR_RX3 BIT(3)
38 #define AC97RXCR_RX4 BIT(4)
39 #define AC97RXCR_CM BIT(15)
40
41 #define AC97TXCR(n) (AC97CH(n) + 0x0008)
42 #define AC97TXCR_TEN BIT(0)
43 #define AC97TXCR_TX3 BIT(3)
44 #define AC97TXCR_TX4 BIT(4)
45 #define AC97TXCR_CM BIT(15)
46
47 #define AC97SR(n) (AC97CH(n) + 0x000c)
48 #define AC97SR_TXFE BIT(1)
49 #define AC97SR_TXUE BIT(6)
50
51 #define AC97RISR(n) (AC97CH(n) + 0x0010)
52 #define AC97ISR(n) (AC97CH(n) + 0x0014)
53 #define AC97IE(n) (AC97CH(n) + 0x0018)
54
55 /*
56 * Global AC97 controller registers.
57 */
58 #define AC97S1DATA 0x0080
59 #define AC97S2DATA 0x0084
60 #define AC97S12DATA 0x0088
61
62 #define AC97RGIS 0x008c
63 #define AC97GIS 0x0090
64 #define AC97IM 0x0094
65 /*
66 * Common bits for RGIS, GIS and IM registers.
67 */
68 #define AC97_SLOT2RXVALID BIT(1)
69 #define AC97_CODECREADY BIT(5)
70 #define AC97_SLOT2TXCOMPLETE BIT(6)
71
72 #define AC97EOI 0x0098
73 #define AC97EOI_WINT BIT(0)
74 #define AC97EOI_CODECREADY BIT(1)
75
76 #define AC97GCR 0x009c
77 #define AC97GCR_AC97IFE BIT(0)
78
79 #define AC97RESET 0x00a0
80 #define AC97RESET_TIMEDRESET BIT(0)
81
82 #define AC97SYNC 0x00a4
83 #define AC97SYNC_TIMEDSYNC BIT(0)
84
85 #define AC97_TIMEOUT msecs_to_jiffies(5)
86
87 /**
88 * struct ep93xx_ac97_info - EP93xx AC97 controller info structure
89 * @lock: mutex serializing access to the bus (slot 1 & 2 ops)
90 * @dev: pointer to the platform device dev structure
91 * @regs: mapped AC97 controller registers
92 * @done: bus ops wait here for an interrupt
93 */
94 struct ep93xx_ac97_info {
95 struct mutex lock;
96 struct device *dev;
97 void __iomem *regs;
98 struct completion done;
99 struct snd_dmaengine_dai_dma_data dma_params_rx;
100 struct snd_dmaengine_dai_dma_data dma_params_tx;
101 };
102
103 /* currently ALSA only supports a single AC97 device */
104 static struct ep93xx_ac97_info *ep93xx_ac97_info;
105
106 static struct ep93xx_dma_data ep93xx_ac97_pcm_out = {
107 .name = "ac97-pcm-out",
108 .port = EP93XX_DMA_AAC1,
109 .direction = DMA_MEM_TO_DEV,
110 };
111
112 static struct ep93xx_dma_data ep93xx_ac97_pcm_in = {
113 .name = "ac97-pcm-in",
114 .port = EP93XX_DMA_AAC1,
115 .direction = DMA_DEV_TO_MEM,
116 };
117
ep93xx_ac97_read_reg(struct ep93xx_ac97_info * info,unsigned reg)118 static inline unsigned ep93xx_ac97_read_reg(struct ep93xx_ac97_info *info,
119 unsigned reg)
120 {
121 return __raw_readl(info->regs + reg);
122 }
123
ep93xx_ac97_write_reg(struct ep93xx_ac97_info * info,unsigned reg,unsigned val)124 static inline void ep93xx_ac97_write_reg(struct ep93xx_ac97_info *info,
125 unsigned reg, unsigned val)
126 {
127 __raw_writel(val, info->regs + reg);
128 }
129
ep93xx_ac97_read(struct snd_ac97 * ac97,unsigned short reg)130 static unsigned short ep93xx_ac97_read(struct snd_ac97 *ac97,
131 unsigned short reg)
132 {
133 struct ep93xx_ac97_info *info = ep93xx_ac97_info;
134 unsigned short val;
135
136 mutex_lock(&info->lock);
137
138 ep93xx_ac97_write_reg(info, AC97S1DATA, reg);
139 ep93xx_ac97_write_reg(info, AC97IM, AC97_SLOT2RXVALID);
140 if (!wait_for_completion_timeout(&info->done, AC97_TIMEOUT)) {
141 dev_warn(info->dev, "timeout reading register %x\n", reg);
142 mutex_unlock(&info->lock);
143 return -ETIMEDOUT;
144 }
145 val = (unsigned short)ep93xx_ac97_read_reg(info, AC97S2DATA);
146
147 mutex_unlock(&info->lock);
148 return val;
149 }
150
ep93xx_ac97_write(struct snd_ac97 * ac97,unsigned short reg,unsigned short val)151 static void ep93xx_ac97_write(struct snd_ac97 *ac97,
152 unsigned short reg,
153 unsigned short val)
154 {
155 struct ep93xx_ac97_info *info = ep93xx_ac97_info;
156
157 mutex_lock(&info->lock);
158
159 /*
160 * Writes to the codec need to be done so that slot 2 is filled in
161 * before slot 1.
162 */
163 ep93xx_ac97_write_reg(info, AC97S2DATA, val);
164 ep93xx_ac97_write_reg(info, AC97S1DATA, reg);
165
166 ep93xx_ac97_write_reg(info, AC97IM, AC97_SLOT2TXCOMPLETE);
167 if (!wait_for_completion_timeout(&info->done, AC97_TIMEOUT))
168 dev_warn(info->dev, "timeout writing register %x\n", reg);
169
170 mutex_unlock(&info->lock);
171 }
172
ep93xx_ac97_warm_reset(struct snd_ac97 * ac97)173 static void ep93xx_ac97_warm_reset(struct snd_ac97 *ac97)
174 {
175 struct ep93xx_ac97_info *info = ep93xx_ac97_info;
176
177 mutex_lock(&info->lock);
178
179 /*
180 * We are assuming that before this functions gets called, the codec
181 * BIT_CLK is stopped by forcing the codec into powerdown mode. We can
182 * control the SYNC signal directly via AC97SYNC register. Using
183 * TIMEDSYNC the controller will keep the SYNC high > 1us.
184 */
185 ep93xx_ac97_write_reg(info, AC97SYNC, AC97SYNC_TIMEDSYNC);
186 ep93xx_ac97_write_reg(info, AC97IM, AC97_CODECREADY);
187 if (!wait_for_completion_timeout(&info->done, AC97_TIMEOUT))
188 dev_warn(info->dev, "codec warm reset timeout\n");
189
190 mutex_unlock(&info->lock);
191 }
192
ep93xx_ac97_cold_reset(struct snd_ac97 * ac97)193 static void ep93xx_ac97_cold_reset(struct snd_ac97 *ac97)
194 {
195 struct ep93xx_ac97_info *info = ep93xx_ac97_info;
196
197 mutex_lock(&info->lock);
198
199 /*
200 * For doing cold reset, we disable the AC97 controller interface, clear
201 * WINT and CODECREADY bits, and finally enable the interface again.
202 */
203 ep93xx_ac97_write_reg(info, AC97GCR, 0);
204 ep93xx_ac97_write_reg(info, AC97EOI, AC97EOI_CODECREADY | AC97EOI_WINT);
205 ep93xx_ac97_write_reg(info, AC97GCR, AC97GCR_AC97IFE);
206
207 /*
208 * Now, assert the reset and wait for the codec to become ready.
209 */
210 ep93xx_ac97_write_reg(info, AC97RESET, AC97RESET_TIMEDRESET);
211 ep93xx_ac97_write_reg(info, AC97IM, AC97_CODECREADY);
212 if (!wait_for_completion_timeout(&info->done, AC97_TIMEOUT))
213 dev_warn(info->dev, "codec cold reset timeout\n");
214
215 /*
216 * Give the codec some time to come fully out from the reset. This way
217 * we ensure that the subsequent reads/writes will work.
218 */
219 usleep_range(15000, 20000);
220
221 mutex_unlock(&info->lock);
222 }
223
ep93xx_ac97_interrupt(int irq,void * dev_id)224 static irqreturn_t ep93xx_ac97_interrupt(int irq, void *dev_id)
225 {
226 struct ep93xx_ac97_info *info = dev_id;
227 unsigned status, mask;
228
229 /*
230 * Just mask out the interrupt and wake up the waiting thread.
231 * Interrupts are cleared via reading/writing to slot 1 & 2 registers by
232 * the waiting thread.
233 */
234 status = ep93xx_ac97_read_reg(info, AC97GIS);
235 mask = ep93xx_ac97_read_reg(info, AC97IM);
236 mask &= ~status;
237 ep93xx_ac97_write_reg(info, AC97IM, mask);
238
239 complete(&info->done);
240 return IRQ_HANDLED;
241 }
242
243 static struct snd_ac97_bus_ops ep93xx_ac97_ops = {
244 .read = ep93xx_ac97_read,
245 .write = ep93xx_ac97_write,
246 .reset = ep93xx_ac97_cold_reset,
247 .warm_reset = ep93xx_ac97_warm_reset,
248 };
249
ep93xx_ac97_trigger(struct snd_pcm_substream * substream,int cmd,struct snd_soc_dai * dai)250 static int ep93xx_ac97_trigger(struct snd_pcm_substream *substream,
251 int cmd, struct snd_soc_dai *dai)
252 {
253 struct ep93xx_ac97_info *info = snd_soc_dai_get_drvdata(dai);
254 unsigned v = 0;
255
256 switch (cmd) {
257 case SNDRV_PCM_TRIGGER_START:
258 case SNDRV_PCM_TRIGGER_RESUME:
259 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
260 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
261 /*
262 * Enable compact mode, TX slots 3 & 4, and the TX FIFO
263 * itself.
264 */
265 v |= AC97TXCR_CM;
266 v |= AC97TXCR_TX3 | AC97TXCR_TX4;
267 v |= AC97TXCR_TEN;
268 ep93xx_ac97_write_reg(info, AC97TXCR(1), v);
269 } else {
270 /*
271 * Enable compact mode, RX slots 3 & 4, and the RX FIFO
272 * itself.
273 */
274 v |= AC97RXCR_CM;
275 v |= AC97RXCR_RX3 | AC97RXCR_RX4;
276 v |= AC97RXCR_REN;
277 ep93xx_ac97_write_reg(info, AC97RXCR(1), v);
278 }
279 break;
280
281 case SNDRV_PCM_TRIGGER_STOP:
282 case SNDRV_PCM_TRIGGER_SUSPEND:
283 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
284 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
285 /*
286 * As per Cirrus EP93xx errata described below:
287 *
288 * https://www.cirrus.com/en/pubs/errata/ER667E2B.pdf
289 *
290 * we will wait for the TX FIFO to be empty before
291 * clearing the TEN bit.
292 */
293 unsigned long timeout = jiffies + AC97_TIMEOUT;
294
295 do {
296 v = ep93xx_ac97_read_reg(info, AC97SR(1));
297 if (time_after(jiffies, timeout)) {
298 dev_warn(info->dev, "TX timeout\n");
299 break;
300 }
301 } while (!(v & (AC97SR_TXFE | AC97SR_TXUE)));
302
303 /* disable the TX FIFO */
304 ep93xx_ac97_write_reg(info, AC97TXCR(1), 0);
305 } else {
306 /* disable the RX FIFO */
307 ep93xx_ac97_write_reg(info, AC97RXCR(1), 0);
308 }
309 break;
310
311 default:
312 dev_warn(info->dev, "unknown command %d\n", cmd);
313 return -EINVAL;
314 }
315
316 return 0;
317 }
318
ep93xx_ac97_dai_probe(struct snd_soc_dai * dai)319 static int ep93xx_ac97_dai_probe(struct snd_soc_dai *dai)
320 {
321 struct ep93xx_ac97_info *info = snd_soc_dai_get_drvdata(dai);
322
323 info->dma_params_tx.filter_data = &ep93xx_ac97_pcm_out;
324 info->dma_params_rx.filter_data = &ep93xx_ac97_pcm_in;
325
326 dai->playback_dma_data = &info->dma_params_tx;
327 dai->capture_dma_data = &info->dma_params_rx;
328
329 return 0;
330 }
331
332 static const struct snd_soc_dai_ops ep93xx_ac97_dai_ops = {
333 .trigger = ep93xx_ac97_trigger,
334 };
335
336 static struct snd_soc_dai_driver ep93xx_ac97_dai = {
337 .name = "ep93xx-ac97",
338 .id = 0,
339 .probe = ep93xx_ac97_dai_probe,
340 .playback = {
341 .stream_name = "AC97 Playback",
342 .channels_min = 2,
343 .channels_max = 2,
344 .rates = SNDRV_PCM_RATE_8000_48000,
345 .formats = SNDRV_PCM_FMTBIT_S16_LE,
346 },
347 .capture = {
348 .stream_name = "AC97 Capture",
349 .channels_min = 2,
350 .channels_max = 2,
351 .rates = SNDRV_PCM_RATE_8000_48000,
352 .formats = SNDRV_PCM_FMTBIT_S16_LE,
353 },
354 .ops = &ep93xx_ac97_dai_ops,
355 };
356
357 static const struct snd_soc_component_driver ep93xx_ac97_component = {
358 .name = "ep93xx-ac97",
359 .legacy_dai_naming = 1,
360 };
361
ep93xx_ac97_probe(struct platform_device * pdev)362 static int ep93xx_ac97_probe(struct platform_device *pdev)
363 {
364 struct ep93xx_ac97_info *info;
365 int irq;
366 int ret;
367
368 info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
369 if (!info)
370 return -ENOMEM;
371
372 info->regs = devm_platform_ioremap_resource(pdev, 0);
373 if (IS_ERR(info->regs))
374 return PTR_ERR(info->regs);
375
376 irq = platform_get_irq(pdev, 0);
377 if (irq <= 0)
378 return irq < 0 ? irq : -ENODEV;
379
380 ret = devm_request_irq(&pdev->dev, irq, ep93xx_ac97_interrupt,
381 IRQF_TRIGGER_HIGH, pdev->name, info);
382 if (ret)
383 goto fail;
384
385 dev_set_drvdata(&pdev->dev, info);
386
387 mutex_init(&info->lock);
388 init_completion(&info->done);
389 info->dev = &pdev->dev;
390
391 ep93xx_ac97_info = info;
392 platform_set_drvdata(pdev, info);
393
394 ret = snd_soc_set_ac97_ops(&ep93xx_ac97_ops);
395 if (ret)
396 goto fail;
397
398 ret = snd_soc_register_component(&pdev->dev, &ep93xx_ac97_component,
399 &ep93xx_ac97_dai, 1);
400 if (ret)
401 goto fail;
402
403 ret = devm_ep93xx_pcm_platform_register(&pdev->dev);
404 if (ret)
405 goto fail_unregister;
406
407 return 0;
408
409 fail_unregister:
410 snd_soc_unregister_component(&pdev->dev);
411 fail:
412 ep93xx_ac97_info = NULL;
413 snd_soc_set_ac97_ops(NULL);
414 return ret;
415 }
416
ep93xx_ac97_remove(struct platform_device * pdev)417 static int ep93xx_ac97_remove(struct platform_device *pdev)
418 {
419 struct ep93xx_ac97_info *info = platform_get_drvdata(pdev);
420
421 snd_soc_unregister_component(&pdev->dev);
422
423 /* disable the AC97 controller */
424 ep93xx_ac97_write_reg(info, AC97GCR, 0);
425
426 ep93xx_ac97_info = NULL;
427
428 snd_soc_set_ac97_ops(NULL);
429
430 return 0;
431 }
432
433 static struct platform_driver ep93xx_ac97_driver = {
434 .probe = ep93xx_ac97_probe,
435 .remove = ep93xx_ac97_remove,
436 .driver = {
437 .name = "ep93xx-ac97",
438 },
439 };
440
441 module_platform_driver(ep93xx_ac97_driver);
442
443 MODULE_DESCRIPTION("EP93xx AC97 ASoC Driver");
444 MODULE_AUTHOR("Mika Westerberg <mika.westerberg@iki.fi>");
445 MODULE_LICENSE("GPL");
446 MODULE_ALIAS("platform:ep93xx-ac97");
447