1// SPDX-License-Identifier: GPL-2.0
2//
3// Driver for Microchip I2S Multi-channel controller
4//
5// Copyright (C) 2018 Microchip Technology Inc. and its subsidiaries
6//
7// Author: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
8
9#include <linux/init.h>
10#include <linux/module.h>
11#include <linux/device.h>
12#include <linux/slab.h>
13
14#include <linux/delay.h>
15#include <linux/io.h>
16#include <linux/clk.h>
17#include <linux/mfd/syscon.h>
18#include <linux/lcm.h>
19#include <linux/of.h>
20
21#include <sound/core.h>
22#include <sound/pcm.h>
23#include <sound/pcm_params.h>
24#include <sound/initval.h>
25#include <sound/soc.h>
26#include <sound/dmaengine_pcm.h>
27
28/*
29 * ---- I2S Controller Register map ----
30 */
31#define MCHP_I2SMCC_CR 0x0000 /* Control Register */
32#define MCHP_I2SMCC_MRA 0x0004 /* Mode Register A */
33#define MCHP_I2SMCC_MRB 0x0008 /* Mode Register B */
34#define MCHP_I2SMCC_SR 0x000C /* Status Register */
35#define MCHP_I2SMCC_IERA 0x0010 /* Interrupt Enable Register A */
36#define MCHP_I2SMCC_IDRA 0x0014 /* Interrupt Disable Register A */
37#define MCHP_I2SMCC_IMRA 0x0018 /* Interrupt Mask Register A */
38#define MCHP_I2SMCC_ISRA 0X001C /* Interrupt Status Register A */
39
40#define MCHP_I2SMCC_IERB 0x0020 /* Interrupt Enable Register B */
41#define MCHP_I2SMCC_IDRB 0x0024 /* Interrupt Disable Register B */
42#define MCHP_I2SMCC_IMRB 0x0028 /* Interrupt Mask Register B */
43#define MCHP_I2SMCC_ISRB 0X002C /* Interrupt Status Register B */
44
45#define MCHP_I2SMCC_RHR 0x0030 /* Receiver Holding Register */
46#define MCHP_I2SMCC_THR 0x0034 /* Transmitter Holding Register */
47
48#define MCHP_I2SMCC_RHL0R 0x0040 /* Receiver Holding Left 0 Register */
49#define MCHP_I2SMCC_RHR0R 0x0044 /* Receiver Holding Right 0 Register */
50
51#define MCHP_I2SMCC_RHL1R 0x0048 /* Receiver Holding Left 1 Register */
52#define MCHP_I2SMCC_RHR1R 0x004C /* Receiver Holding Right 1 Register */
53
54#define MCHP_I2SMCC_RHL2R 0x0050 /* Receiver Holding Left 2 Register */
55#define MCHP_I2SMCC_RHR2R 0x0054 /* Receiver Holding Right 2 Register */
56
57#define MCHP_I2SMCC_RHL3R 0x0058 /* Receiver Holding Left 3 Register */
58#define MCHP_I2SMCC_RHR3R 0x005C /* Receiver Holding Right 3 Register */
59
60#define MCHP_I2SMCC_THL0R 0x0060 /* Transmitter Holding Left 0 Register */
61#define MCHP_I2SMCC_THR0R 0x0064 /* Transmitter Holding Right 0 Register */
62
63#define MCHP_I2SMCC_THL1R 0x0068 /* Transmitter Holding Left 1 Register */
64#define MCHP_I2SMCC_THR1R 0x006C /* Transmitter Holding Right 1 Register */
65
66#define MCHP_I2SMCC_THL2R 0x0070 /* Transmitter Holding Left 2 Register */
67#define MCHP_I2SMCC_THR2R 0x0074 /* Transmitter Holding Right 2 Register */
68
69#define MCHP_I2SMCC_THL3R 0x0078 /* Transmitter Holding Left 3 Register */
70#define MCHP_I2SMCC_THR3R 0x007C /* Transmitter Holding Right 3 Register */
71
72#define MCHP_I2SMCC_VERSION 0x00FC /* Version Register */
73
74/*
75 * ---- Control Register (Write-only) ----
76 */
77#define MCHP_I2SMCC_CR_RXEN BIT(0) /* Receiver Enable */
78#define MCHP_I2SMCC_CR_RXDIS BIT(1) /* Receiver Disable */
79#define MCHP_I2SMCC_CR_CKEN BIT(2) /* Clock Enable */
80#define MCHP_I2SMCC_CR_CKDIS BIT(3) /* Clock Disable */
81#define MCHP_I2SMCC_CR_TXEN BIT(4) /* Transmitter Enable */
82#define MCHP_I2SMCC_CR_TXDIS BIT(5) /* Transmitter Disable */
83#define MCHP_I2SMCC_CR_SWRST BIT(7) /* Software Reset */
84
85/*
86 * ---- Mode Register A (Read/Write) ----
87 */
88#define MCHP_I2SMCC_MRA_MODE_MASK GENMASK(0, 0)
89#define MCHP_I2SMCC_MRA_MODE_SLAVE (0 << 0)
90#define MCHP_I2SMCC_MRA_MODE_MASTER (1 << 0)
91
92#define MCHP_I2SMCC_MRA_DATALENGTH_MASK GENMASK(3, 1)
93#define MCHP_I2SMCC_MRA_DATALENGTH_32_BITS (0 << 1)
94#define MCHP_I2SMCC_MRA_DATALENGTH_24_BITS (1 << 1)
95#define MCHP_I2SMCC_MRA_DATALENGTH_20_BITS (2 << 1)
96#define MCHP_I2SMCC_MRA_DATALENGTH_18_BITS (3 << 1)
97#define MCHP_I2SMCC_MRA_DATALENGTH_16_BITS (4 << 1)
98#define MCHP_I2SMCC_MRA_DATALENGTH_16_BITS_COMPACT (5 << 1)
99#define MCHP_I2SMCC_MRA_DATALENGTH_8_BITS (6 << 1)
100#define MCHP_I2SMCC_MRA_DATALENGTH_8_BITS_COMPACT (7 << 1)
101
102#define MCHP_I2SMCC_MRA_WIRECFG_MASK GENMASK(5, 4)
103#define MCHP_I2SMCC_MRA_WIRECFG_TDM(pin) (((pin) << 4) & \
104 MCHP_I2SMCC_MRA_WIRECFG_MASK)
105#define MCHP_I2SMCC_MRA_WIRECFG_I2S_1_TDM_0 (0 << 4)
106#define MCHP_I2SMCC_MRA_WIRECFG_I2S_2_TDM_1 (1 << 4)
107#define MCHP_I2SMCC_MRA_WIRECFG_I2S_4_TDM_2 (2 << 4)
108#define MCHP_I2SMCC_MRA_WIRECFG_TDM_3 (3 << 4)
109
110#define MCHP_I2SMCC_MRA_FORMAT_MASK GENMASK(7, 6)
111#define MCHP_I2SMCC_MRA_FORMAT_I2S (0 << 6)
112#define MCHP_I2SMCC_MRA_FORMAT_LJ (1 << 6) /* Left Justified */
113#define MCHP_I2SMCC_MRA_FORMAT_TDM (2 << 6)
114#define MCHP_I2SMCC_MRA_FORMAT_TDMLJ (3 << 6)
115
116/* Transmitter uses one DMA channel ... */
117/* Left audio samples duplicated to right audio channel */
118#define MCHP_I2SMCC_MRA_RXMONO BIT(8)
119
120/* I2SDO output of I2SC is internally connected to I2SDI input */
121#define MCHP_I2SMCC_MRA_RXLOOP BIT(9)
122
123/* Receiver uses one DMA channel ... */
124/* Left audio samples duplicated to right audio channel */
125#define MCHP_I2SMCC_MRA_TXMONO BIT(10)
126
127/* x sample transmitted when underrun */
128#define MCHP_I2SMCC_MRA_TXSAME_ZERO (0 << 11) /* Zero sample */
129#define MCHP_I2SMCC_MRA_TXSAME_PREVIOUS (1 << 11) /* Previous sample */
130
131/* select between peripheral clock and generated clock */
132#define MCHP_I2SMCC_MRA_SRCCLK_PCLK (0 << 12)
133#define MCHP_I2SMCC_MRA_SRCCLK_GCLK (1 << 12)
134
135/* Number of TDM Channels - 1 */
136#define MCHP_I2SMCC_MRA_NBCHAN_MASK GENMASK(15, 13)
137#define MCHP_I2SMCC_MRA_NBCHAN(ch) \
138 ((((ch) - 1) << 13) & MCHP_I2SMCC_MRA_NBCHAN_MASK)
139
140/* Selected Clock to I2SMCC Master Clock ratio */
141#define MCHP_I2SMCC_MRA_IMCKDIV_MASK GENMASK(21, 16)
142#define MCHP_I2SMCC_MRA_IMCKDIV(div) \
143 (((div) << 16) & MCHP_I2SMCC_MRA_IMCKDIV_MASK)
144
145/* TDM Frame Synchronization */
146#define MCHP_I2SMCC_MRA_TDMFS_MASK GENMASK(23, 22)
147#define MCHP_I2SMCC_MRA_TDMFS_SLOT (0 << 22)
148#define MCHP_I2SMCC_MRA_TDMFS_HALF (1 << 22)
149#define MCHP_I2SMCC_MRA_TDMFS_BIT (2 << 22)
150
151/* Selected Clock to I2SMC Serial Clock ratio */
152#define MCHP_I2SMCC_MRA_ISCKDIV_MASK GENMASK(29, 24)
153#define MCHP_I2SMCC_MRA_ISCKDIV(div) \
154 (((div) << 24) & MCHP_I2SMCC_MRA_ISCKDIV_MASK)
155
156/* Master Clock mode */
157#define MCHP_I2SMCC_MRA_IMCKMODE_MASK GENMASK(30, 30)
158/* 0: No master clock generated*/
159#define MCHP_I2SMCC_MRA_IMCKMODE_NONE (0 << 30)
160/* 1: master clock generated (internally generated clock drives I2SMCK pin) */
161#define MCHP_I2SMCC_MRA_IMCKMODE_GEN (1 << 30)
162
163/* Slot Width */
164/* 0: slot is 32 bits wide for DATALENGTH = 18/20/24 bits. */
165/* 1: slot is 24 bits wide for DATALENGTH = 18/20/24 bits. */
166#define MCHP_I2SMCC_MRA_IWS BIT(31)
167
168/*
169 * ---- Mode Register B (Read/Write) ----
170 */
171/* all enabled I2S left channels are filled first, then I2S right channels */
172#define MCHP_I2SMCC_MRB_CRAMODE_LEFT_FIRST (0 << 0)
173/*
174 * an enabled I2S left channel is filled, then the corresponding right
175 * channel, until all channels are filled
176 */
177#define MCHP_I2SMCC_MRB_CRAMODE_REGULAR (1 << 0)
178
179#define MCHP_I2SMCC_MRB_FIFOEN BIT(4)
180
181#define MCHP_I2SMCC_MRB_DMACHUNK_MASK GENMASK(9, 8)
182#define MCHP_I2SMCC_MRB_DMACHUNK(no_words) \
183 (((fls(no_words) - 1) << 8) & MCHP_I2SMCC_MRB_DMACHUNK_MASK)
184
185#define MCHP_I2SMCC_MRB_CLKSEL_MASK GENMASK(16, 16)
186#define MCHP_I2SMCC_MRB_CLKSEL_EXT (0 << 16)
187#define MCHP_I2SMCC_MRB_CLKSEL_INT (1 << 16)
188
189/*
190 * ---- Status Registers (Read-only) ----
191 */
192#define MCHP_I2SMCC_SR_RXEN BIT(0) /* Receiver Enabled */
193#define MCHP_I2SMCC_SR_TXEN BIT(4) /* Transmitter Enabled */
194
195/*
196 * ---- Interrupt Enable/Disable/Mask/Status Registers A ----
197 */
198#define MCHP_I2SMCC_INT_TXRDY_MASK(ch) GENMASK((ch) - 1, 0)
199#define MCHP_I2SMCC_INT_TXRDYCH(ch) BIT(ch)
200#define MCHP_I2SMCC_INT_TXUNF_MASK(ch) GENMASK((ch) + 7, 8)
201#define MCHP_I2SMCC_INT_TXUNFCH(ch) BIT((ch) + 8)
202#define MCHP_I2SMCC_INT_RXRDY_MASK(ch) GENMASK((ch) + 15, 16)
203#define MCHP_I2SMCC_INT_RXRDYCH(ch) BIT((ch) + 16)
204#define MCHP_I2SMCC_INT_RXOVF_MASK(ch) GENMASK((ch) + 23, 24)
205#define MCHP_I2SMCC_INT_RXOVFCH(ch) BIT((ch) + 24)
206
207/*
208 * ---- Interrupt Enable/Disable/Mask/Status Registers B ----
209 */
210#define MCHP_I2SMCC_INT_WERR BIT(0)
211#define MCHP_I2SMCC_INT_TXFFRDY BIT(8)
212#define MCHP_I2SMCC_INT_TXFFEMP BIT(9)
213#define MCHP_I2SMCC_INT_RXFFRDY BIT(12)
214#define MCHP_I2SMCC_INT_RXFFFUL BIT(13)
215
216/*
217 * ---- Version Register (Read-only) ----
218 */
219#define MCHP_I2SMCC_VERSION_MASK GENMASK(11, 0)
220
221#define MCHP_I2SMCC_MAX_CHANNELS 8
222#define MCHP_I2MCC_TDM_SLOT_WIDTH 32
223
224static const struct regmap_config mchp_i2s_mcc_regmap_config = {
225 .reg_bits = 32,
226 .reg_stride = 4,
227 .val_bits = 32,
228 .max_register = MCHP_I2SMCC_VERSION,
229};
230
231struct mchp_i2s_mcc_soc_data {
232 unsigned int data_pin_pair_num;
233 bool has_fifo;
234};
235
236struct mchp_i2s_mcc_dev {
237 struct wait_queue_head wq_txrdy;
238 struct wait_queue_head wq_rxrdy;
239 struct device *dev;
240 struct regmap *regmap;
241 struct clk *pclk;
242 struct clk *gclk;
243 const struct mchp_i2s_mcc_soc_data *soc;
244 struct snd_dmaengine_dai_dma_data playback;
245 struct snd_dmaengine_dai_dma_data capture;
246 unsigned int fmt;
247 unsigned int sysclk;
248 unsigned int frame_length;
249 int tdm_slots;
250 int channels;
251 u8 tdm_data_pair;
252 unsigned int gclk_use:1;
253 unsigned int gclk_running:1;
254 unsigned int tx_rdy:1;
255 unsigned int rx_rdy:1;
256};
257
258static irqreturn_t mchp_i2s_mcc_interrupt(int irq, void *dev_id)
259{
260 struct mchp_i2s_mcc_dev *dev = dev_id;
261 u32 sra, imra, srb, imrb, pendinga, pendingb, idra = 0, idrb = 0;
262 irqreturn_t ret = IRQ_NONE;
263
264 regmap_read(map: dev->regmap, MCHP_I2SMCC_IMRA, val: &imra);
265 regmap_read(map: dev->regmap, MCHP_I2SMCC_ISRA, val: &sra);
266 pendinga = imra & sra;
267
268 regmap_read(map: dev->regmap, MCHP_I2SMCC_IMRB, val: &imrb);
269 regmap_read(map: dev->regmap, MCHP_I2SMCC_ISRB, val: &srb);
270 pendingb = imrb & srb;
271
272 if (!pendinga && !pendingb)
273 return IRQ_NONE;
274
275 /*
276 * Tx/Rx ready interrupts are enabled when stopping only, to assure
277 * availability and to disable clocks if necessary
278 */
279 if (dev->soc->has_fifo) {
280 idrb |= pendingb & (MCHP_I2SMCC_INT_TXFFRDY |
281 MCHP_I2SMCC_INT_RXFFRDY);
282 } else {
283 idra |= pendinga & (MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels) |
284 MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels));
285 }
286 if (idra || idrb)
287 ret = IRQ_HANDLED;
288
289 if ((!dev->soc->has_fifo &&
290 (imra & MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels)) &&
291 (imra & MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels)) ==
292 (idra & MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels))) ||
293 (dev->soc->has_fifo && imrb & MCHP_I2SMCC_INT_TXFFRDY)) {
294 dev->tx_rdy = 1;
295 wake_up_interruptible(&dev->wq_txrdy);
296 }
297 if ((!dev->soc->has_fifo &&
298 (imra & MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels)) &&
299 (imra & MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels)) ==
300 (idra & MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels))) ||
301 (dev->soc->has_fifo && imrb & MCHP_I2SMCC_INT_RXFFRDY)) {
302 dev->rx_rdy = 1;
303 wake_up_interruptible(&dev->wq_rxrdy);
304 }
305 if (dev->soc->has_fifo)
306 regmap_write(map: dev->regmap, MCHP_I2SMCC_IDRB, val: idrb);
307 else
308 regmap_write(map: dev->regmap, MCHP_I2SMCC_IDRA, val: idra);
309
310 return ret;
311}
312
313static int mchp_i2s_mcc_set_sysclk(struct snd_soc_dai *dai,
314 int clk_id, unsigned int freq, int dir)
315{
316 struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai);
317
318 dev_dbg(dev->dev, "%s() clk_id=%d freq=%u dir=%d\n",
319 __func__, clk_id, freq, dir);
320
321 /* We do not need SYSCLK */
322 if (dir == SND_SOC_CLOCK_IN)
323 return 0;
324
325 dev->sysclk = freq;
326
327 return 0;
328}
329
330static int mchp_i2s_mcc_set_bclk_ratio(struct snd_soc_dai *dai,
331 unsigned int ratio)
332{
333 struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai);
334
335 dev_dbg(dev->dev, "%s() ratio=%u\n", __func__, ratio);
336
337 dev->frame_length = ratio;
338
339 return 0;
340}
341
342static int mchp_i2s_mcc_set_dai_fmt(struct snd_soc_dai *dai, unsigned int fmt)
343{
344 struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai);
345
346 dev_dbg(dev->dev, "%s() fmt=%#x\n", __func__, fmt);
347
348 /* We don't support any kind of clock inversion */
349 if ((fmt & SND_SOC_DAIFMT_INV_MASK) != SND_SOC_DAIFMT_NB_NF)
350 return -EINVAL;
351
352 /* We can't generate only FSYNC */
353 if ((fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) == SND_SOC_DAIFMT_BC_FP)
354 return -EINVAL;
355
356 /* We can only reconfigure the IP when it's stopped */
357 if (fmt & SND_SOC_DAIFMT_CONT)
358 return -EINVAL;
359
360 dev->fmt = fmt;
361
362 return 0;
363}
364
365static int mchp_i2s_mcc_set_dai_tdm_slot(struct snd_soc_dai *dai,
366 unsigned int tx_mask,
367 unsigned int rx_mask,
368 int slots, int slot_width)
369{
370 struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai);
371
372 dev_dbg(dev->dev,
373 "%s() tx_mask=0x%08x rx_mask=0x%08x slots=%d width=%d\n",
374 __func__, tx_mask, rx_mask, slots, slot_width);
375
376 if (slots < 0 || slots > MCHP_I2SMCC_MAX_CHANNELS ||
377 slot_width != MCHP_I2MCC_TDM_SLOT_WIDTH)
378 return -EINVAL;
379
380 if (slots) {
381 /* We do not support daisy chain */
382 if (rx_mask != GENMASK(slots - 1, 0) ||
383 rx_mask != tx_mask)
384 return -EINVAL;
385 }
386
387 dev->tdm_slots = slots;
388 dev->frame_length = slots * MCHP_I2MCC_TDM_SLOT_WIDTH;
389
390 return 0;
391}
392
393static int mchp_i2s_mcc_clk_get_rate_diff(struct clk *clk,
394 unsigned long rate,
395 struct clk **best_clk,
396 unsigned long *best_rate,
397 unsigned long *best_diff_rate)
398{
399 long round_rate;
400 unsigned int diff_rate;
401
402 round_rate = clk_round_rate(clk, rate);
403 if (round_rate < 0)
404 return (int)round_rate;
405
406 diff_rate = abs(rate - round_rate);
407 if (diff_rate < *best_diff_rate) {
408 *best_clk = clk;
409 *best_diff_rate = diff_rate;
410 *best_rate = rate;
411 }
412
413 return 0;
414}
415
416static int mchp_i2s_mcc_config_divs(struct mchp_i2s_mcc_dev *dev,
417 unsigned int bclk, unsigned int *mra,
418 unsigned long *best_rate)
419{
420 unsigned long clk_rate;
421 unsigned long lcm_rate;
422 unsigned long best_diff_rate = ~0;
423 unsigned int sysclk;
424 struct clk *best_clk = NULL;
425 int ret;
426
427 /* For code simplification */
428 if (!dev->sysclk)
429 sysclk = bclk;
430 else
431 sysclk = dev->sysclk;
432
433 /*
434 * MCLK is Selected CLK / (2 * IMCKDIV),
435 * BCLK is Selected CLK / (2 * ISCKDIV);
436 * if IMCKDIV or ISCKDIV are 0, MCLK or BCLK = Selected CLK
437 */
438 lcm_rate = lcm(a: sysclk, b: bclk);
439 if ((lcm_rate / sysclk % 2 == 1 && lcm_rate / sysclk > 2) ||
440 (lcm_rate / bclk % 2 == 1 && lcm_rate / bclk > 2))
441 lcm_rate *= 2;
442
443 for (clk_rate = lcm_rate;
444 (clk_rate == sysclk || clk_rate / (sysclk * 2) <= GENMASK(5, 0)) &&
445 (clk_rate == bclk || clk_rate / (bclk * 2) <= GENMASK(5, 0));
446 clk_rate += lcm_rate) {
447 ret = mchp_i2s_mcc_clk_get_rate_diff(clk: dev->gclk, rate: clk_rate,
448 best_clk: &best_clk, best_rate,
449 best_diff_rate: &best_diff_rate);
450 if (ret) {
451 dev_err(dev->dev, "gclk error for rate %lu: %d",
452 clk_rate, ret);
453 } else {
454 if (!best_diff_rate) {
455 dev_dbg(dev->dev, "found perfect rate on gclk: %lu\n",
456 clk_rate);
457 break;
458 }
459 }
460
461 ret = mchp_i2s_mcc_clk_get_rate_diff(clk: dev->pclk, rate: clk_rate,
462 best_clk: &best_clk, best_rate,
463 best_diff_rate: &best_diff_rate);
464 if (ret) {
465 dev_err(dev->dev, "pclk error for rate %lu: %d",
466 clk_rate, ret);
467 } else {
468 if (!best_diff_rate) {
469 dev_dbg(dev->dev, "found perfect rate on pclk: %lu\n",
470 clk_rate);
471 break;
472 }
473 }
474 }
475
476 /* check if clocks returned only errors */
477 if (!best_clk) {
478 dev_err(dev->dev, "unable to change rate to clocks\n");
479 return -EINVAL;
480 }
481
482 dev_dbg(dev->dev, "source CLK is %s with rate %lu, diff %lu\n",
483 best_clk == dev->pclk ? "pclk" : "gclk",
484 *best_rate, best_diff_rate);
485
486 /* Configure divisors */
487 if (dev->sysclk)
488 *mra |= MCHP_I2SMCC_MRA_IMCKDIV(*best_rate / (2 * sysclk));
489 *mra |= MCHP_I2SMCC_MRA_ISCKDIV(*best_rate / (2 * bclk));
490
491 if (best_clk == dev->gclk)
492 *mra |= MCHP_I2SMCC_MRA_SRCCLK_GCLK;
493 else
494 *mra |= MCHP_I2SMCC_MRA_SRCCLK_PCLK;
495
496 return 0;
497}
498
499static int mchp_i2s_mcc_is_running(struct mchp_i2s_mcc_dev *dev)
500{
501 u32 sr;
502
503 regmap_read(map: dev->regmap, MCHP_I2SMCC_SR, val: &sr);
504 return !!(sr & (MCHP_I2SMCC_SR_TXEN | MCHP_I2SMCC_SR_RXEN));
505}
506
507static int mchp_i2s_mcc_hw_params(struct snd_pcm_substream *substream,
508 struct snd_pcm_hw_params *params,
509 struct snd_soc_dai *dai)
510{
511 unsigned long rate = 0;
512 struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai);
513 u32 mra = 0;
514 u32 mrb = 0;
515 unsigned int channels = params_channels(p: params);
516 unsigned int frame_length = dev->frame_length;
517 unsigned int bclk_rate;
518 int set_divs = 0;
519 int ret;
520 bool is_playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
521
522 dev_dbg(dev->dev, "%s() rate=%u format=%#x width=%u channels=%u\n",
523 __func__, params_rate(params), params_format(params),
524 params_width(params), params_channels(params));
525
526 switch (dev->fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
527 case SND_SOC_DAIFMT_I2S:
528 if (dev->tdm_slots) {
529 dev_err(dev->dev, "I2S with TDM is not supported\n");
530 return -EINVAL;
531 }
532 mra |= MCHP_I2SMCC_MRA_FORMAT_I2S;
533 break;
534 case SND_SOC_DAIFMT_LEFT_J:
535 if (dev->tdm_slots) {
536 dev_err(dev->dev, "Left-Justified with TDM is not supported\n");
537 return -EINVAL;
538 }
539 mra |= MCHP_I2SMCC_MRA_FORMAT_LJ;
540 break;
541 case SND_SOC_DAIFMT_DSP_A:
542 mra |= MCHP_I2SMCC_MRA_FORMAT_TDM;
543 break;
544 default:
545 dev_err(dev->dev, "unsupported bus format\n");
546 return -EINVAL;
547 }
548
549 switch (dev->fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) {
550 case SND_SOC_DAIFMT_BP_FP:
551 /* cpu is BCLK and LRC master */
552 mra |= MCHP_I2SMCC_MRA_MODE_MASTER;
553 if (dev->sysclk)
554 mra |= MCHP_I2SMCC_MRA_IMCKMODE_GEN;
555 set_divs = 1;
556 break;
557 case SND_SOC_DAIFMT_BP_FC:
558 /* cpu is BCLK master */
559 mrb |= MCHP_I2SMCC_MRB_CLKSEL_INT;
560 set_divs = 1;
561 fallthrough;
562 case SND_SOC_DAIFMT_BC_FC:
563 /* cpu is slave */
564 mra |= MCHP_I2SMCC_MRA_MODE_SLAVE;
565 if (dev->sysclk)
566 dev_warn(dev->dev, "Unable to generate MCLK in Slave mode\n");
567 break;
568 default:
569 dev_err(dev->dev, "unsupported master/slave mode\n");
570 return -EINVAL;
571 }
572
573 if (dev->fmt & (SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_LEFT_J)) {
574 /* for I2S and LEFT_J one pin is needed for every 2 channels */
575 if (channels > dev->soc->data_pin_pair_num * 2) {
576 dev_err(dev->dev,
577 "unsupported number of audio channels: %d\n",
578 channels);
579 return -EINVAL;
580 }
581
582 /* enable for interleaved format */
583 mrb |= MCHP_I2SMCC_MRB_CRAMODE_REGULAR;
584
585 switch (channels) {
586 case 1:
587 if (is_playback)
588 mra |= MCHP_I2SMCC_MRA_TXMONO;
589 else
590 mra |= MCHP_I2SMCC_MRA_RXMONO;
591 break;
592 case 2:
593 break;
594 case 4:
595 mra |= MCHP_I2SMCC_MRA_WIRECFG_I2S_2_TDM_1;
596 break;
597 case 8:
598 mra |= MCHP_I2SMCC_MRA_WIRECFG_I2S_4_TDM_2;
599 break;
600 default:
601 dev_err(dev->dev, "unsupported number of audio channels\n");
602 return -EINVAL;
603 }
604
605 if (!frame_length)
606 frame_length = 2 * params_physical_width(p: params);
607 } else if (dev->fmt & SND_SOC_DAIFMT_DSP_A) {
608 mra |= MCHP_I2SMCC_MRA_WIRECFG_TDM(dev->tdm_data_pair);
609
610 if (dev->tdm_slots) {
611 if (channels % 2 && channels * 2 <= dev->tdm_slots) {
612 /*
613 * Duplicate data for even-numbered channels
614 * to odd-numbered channels
615 */
616 if (is_playback)
617 mra |= MCHP_I2SMCC_MRA_TXMONO;
618 else
619 mra |= MCHP_I2SMCC_MRA_RXMONO;
620 }
621 channels = dev->tdm_slots;
622 }
623
624 mra |= MCHP_I2SMCC_MRA_NBCHAN(channels);
625 if (!frame_length)
626 frame_length = channels * MCHP_I2MCC_TDM_SLOT_WIDTH;
627 }
628
629 /*
630 * We must have the same burst size configured
631 * in the DMA transfer and in out IP
632 */
633 mrb |= MCHP_I2SMCC_MRB_DMACHUNK(channels);
634 if (is_playback)
635 dev->playback.maxburst = 1 << (fls(x: channels) - 1);
636 else
637 dev->capture.maxburst = 1 << (fls(x: channels) - 1);
638
639 switch (params_format(p: params)) {
640 case SNDRV_PCM_FORMAT_S8:
641 mra |= MCHP_I2SMCC_MRA_DATALENGTH_8_BITS;
642 break;
643 case SNDRV_PCM_FORMAT_S16_LE:
644 mra |= MCHP_I2SMCC_MRA_DATALENGTH_16_BITS;
645 break;
646 case SNDRV_PCM_FORMAT_S18_3LE:
647 mra |= MCHP_I2SMCC_MRA_DATALENGTH_18_BITS |
648 MCHP_I2SMCC_MRA_IWS;
649 break;
650 case SNDRV_PCM_FORMAT_S20_3LE:
651 mra |= MCHP_I2SMCC_MRA_DATALENGTH_20_BITS |
652 MCHP_I2SMCC_MRA_IWS;
653 break;
654 case SNDRV_PCM_FORMAT_S24_3LE:
655 mra |= MCHP_I2SMCC_MRA_DATALENGTH_24_BITS |
656 MCHP_I2SMCC_MRA_IWS;
657 break;
658 case SNDRV_PCM_FORMAT_S24_LE:
659 mra |= MCHP_I2SMCC_MRA_DATALENGTH_24_BITS;
660 break;
661 case SNDRV_PCM_FORMAT_S32_LE:
662 mra |= MCHP_I2SMCC_MRA_DATALENGTH_32_BITS;
663 break;
664 default:
665 dev_err(dev->dev, "unsupported size/endianness for audio samples\n");
666 return -EINVAL;
667 }
668
669 if (set_divs) {
670 bclk_rate = frame_length * params_rate(p: params);
671 ret = mchp_i2s_mcc_config_divs(dev, bclk: bclk_rate, mra: &mra,
672 best_rate: &rate);
673 if (ret) {
674 dev_err(dev->dev,
675 "unable to configure the divisors: %d\n", ret);
676 return ret;
677 }
678 }
679
680 /* enable FIFO if available */
681 if (dev->soc->has_fifo)
682 mrb |= MCHP_I2SMCC_MRB_FIFOEN;
683
684 /*
685 * If we are already running, the wanted setup must be
686 * the same with the one that's currently ongoing
687 */
688 if (mchp_i2s_mcc_is_running(dev)) {
689 u32 mra_cur;
690 u32 mrb_cur;
691
692 regmap_read(map: dev->regmap, MCHP_I2SMCC_MRA, val: &mra_cur);
693 regmap_read(map: dev->regmap, MCHP_I2SMCC_MRB, val: &mrb_cur);
694 if (mra != mra_cur || mrb != mrb_cur)
695 return -EINVAL;
696
697 return 0;
698 }
699
700 if (mra & MCHP_I2SMCC_MRA_SRCCLK_GCLK && !dev->gclk_use) {
701 /* set the rate */
702 ret = clk_set_rate(clk: dev->gclk, rate);
703 if (ret) {
704 dev_err(dev->dev,
705 "unable to set rate %lu to GCLK: %d\n",
706 rate, ret);
707 return ret;
708 }
709
710 ret = clk_prepare(clk: dev->gclk);
711 if (ret < 0) {
712 dev_err(dev->dev, "unable to prepare GCLK: %d\n", ret);
713 return ret;
714 }
715 dev->gclk_use = 1;
716 }
717
718 /* Save the number of channels to know what interrupts to enable */
719 dev->channels = channels;
720
721 ret = regmap_write(map: dev->regmap, MCHP_I2SMCC_MRA, val: mra);
722 if (ret < 0) {
723 if (dev->gclk_use) {
724 clk_unprepare(clk: dev->gclk);
725 dev->gclk_use = 0;
726 }
727 return ret;
728 }
729 return regmap_write(map: dev->regmap, MCHP_I2SMCC_MRB, val: mrb);
730}
731
732static int mchp_i2s_mcc_hw_free(struct snd_pcm_substream *substream,
733 struct snd_soc_dai *dai)
734{
735 struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai);
736 bool is_playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
737 long err;
738
739 if (is_playback) {
740 err = wait_event_interruptible_timeout(dev->wq_txrdy,
741 dev->tx_rdy,
742 msecs_to_jiffies(500));
743 if (err == 0) {
744 dev_warn_once(dev->dev,
745 "Timeout waiting for Tx ready\n");
746 if (dev->soc->has_fifo)
747 regmap_write(map: dev->regmap, MCHP_I2SMCC_IDRB,
748 MCHP_I2SMCC_INT_TXFFRDY);
749 else
750 regmap_write(map: dev->regmap, MCHP_I2SMCC_IDRA,
751 MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels));
752
753 dev->tx_rdy = 1;
754 }
755 } else {
756 err = wait_event_interruptible_timeout(dev->wq_rxrdy,
757 dev->rx_rdy,
758 msecs_to_jiffies(500));
759 if (err == 0) {
760 dev_warn_once(dev->dev,
761 "Timeout waiting for Rx ready\n");
762 if (dev->soc->has_fifo)
763 regmap_write(map: dev->regmap, MCHP_I2SMCC_IDRB,
764 MCHP_I2SMCC_INT_RXFFRDY);
765 else
766 regmap_write(map: dev->regmap, MCHP_I2SMCC_IDRA,
767 MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels));
768 dev->rx_rdy = 1;
769 }
770 }
771
772 if (!mchp_i2s_mcc_is_running(dev)) {
773 regmap_write(map: dev->regmap, MCHP_I2SMCC_CR, MCHP_I2SMCC_CR_CKDIS);
774
775 if (dev->gclk_running) {
776 clk_disable(clk: dev->gclk);
777 dev->gclk_running = 0;
778 }
779 if (dev->gclk_use) {
780 clk_unprepare(clk: dev->gclk);
781 dev->gclk_use = 0;
782 }
783 }
784
785 return 0;
786}
787
788static int mchp_i2s_mcc_trigger(struct snd_pcm_substream *substream, int cmd,
789 struct snd_soc_dai *dai)
790{
791 struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai);
792 bool is_playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
793 u32 cr = 0;
794 u32 iera = 0, ierb = 0;
795 u32 sr;
796 int err;
797
798 switch (cmd) {
799 case SNDRV_PCM_TRIGGER_START:
800 case SNDRV_PCM_TRIGGER_RESUME:
801 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
802 if (is_playback)
803 cr = MCHP_I2SMCC_CR_TXEN | MCHP_I2SMCC_CR_CKEN;
804 else
805 cr = MCHP_I2SMCC_CR_RXEN | MCHP_I2SMCC_CR_CKEN;
806 break;
807 case SNDRV_PCM_TRIGGER_STOP:
808 case SNDRV_PCM_TRIGGER_SUSPEND:
809 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
810 regmap_read(map: dev->regmap, MCHP_I2SMCC_SR, val: &sr);
811 if (is_playback && (sr & MCHP_I2SMCC_SR_TXEN)) {
812 cr = MCHP_I2SMCC_CR_TXDIS;
813 dev->tx_rdy = 0;
814 /*
815 * Enable Tx Ready interrupts on all channels
816 * to assure all data is sent
817 */
818 if (dev->soc->has_fifo)
819 ierb = MCHP_I2SMCC_INT_TXFFRDY;
820 else
821 iera = MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels);
822 } else if (!is_playback && (sr & MCHP_I2SMCC_SR_RXEN)) {
823 cr = MCHP_I2SMCC_CR_RXDIS;
824 dev->rx_rdy = 0;
825 /*
826 * Enable Rx Ready interrupts on all channels
827 * to assure all data is received
828 */
829 if (dev->soc->has_fifo)
830 ierb = MCHP_I2SMCC_INT_RXFFRDY;
831 else
832 iera = MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels);
833 }
834 break;
835 default:
836 return -EINVAL;
837 }
838
839 if ((cr & MCHP_I2SMCC_CR_CKEN) && dev->gclk_use &&
840 !dev->gclk_running) {
841 err = clk_enable(clk: dev->gclk);
842 if (err) {
843 dev_err_once(dev->dev, "failed to enable GCLK: %d\n",
844 err);
845 } else {
846 dev->gclk_running = 1;
847 }
848 }
849
850 if (dev->soc->has_fifo)
851 regmap_write(map: dev->regmap, MCHP_I2SMCC_IERB, val: ierb);
852 else
853 regmap_write(map: dev->regmap, MCHP_I2SMCC_IERA, val: iera);
854 regmap_write(map: dev->regmap, MCHP_I2SMCC_CR, val: cr);
855
856 return 0;
857}
858
859static int mchp_i2s_mcc_startup(struct snd_pcm_substream *substream,
860 struct snd_soc_dai *dai)
861{
862 struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai);
863
864 /* Software reset the IP if it's not running */
865 if (!mchp_i2s_mcc_is_running(dev)) {
866 return regmap_write(map: dev->regmap, MCHP_I2SMCC_CR,
867 MCHP_I2SMCC_CR_SWRST);
868 }
869
870 return 0;
871}
872
873static int mchp_i2s_mcc_dai_probe(struct snd_soc_dai *dai)
874{
875 struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai);
876
877 init_waitqueue_head(&dev->wq_txrdy);
878 init_waitqueue_head(&dev->wq_rxrdy);
879 dev->tx_rdy = 1;
880 dev->rx_rdy = 1;
881
882 snd_soc_dai_init_dma_data(dai, playback: &dev->playback, capture: &dev->capture);
883
884 return 0;
885}
886
887static const struct snd_soc_dai_ops mchp_i2s_mcc_dai_ops = {
888 .probe = mchp_i2s_mcc_dai_probe,
889 .set_sysclk = mchp_i2s_mcc_set_sysclk,
890 .set_bclk_ratio = mchp_i2s_mcc_set_bclk_ratio,
891 .startup = mchp_i2s_mcc_startup,
892 .trigger = mchp_i2s_mcc_trigger,
893 .hw_params = mchp_i2s_mcc_hw_params,
894 .hw_free = mchp_i2s_mcc_hw_free,
895 .set_fmt = mchp_i2s_mcc_set_dai_fmt,
896 .set_tdm_slot = mchp_i2s_mcc_set_dai_tdm_slot,
897};
898
899#define MCHP_I2SMCC_RATES SNDRV_PCM_RATE_8000_192000
900
901#define MCHP_I2SMCC_FORMATS (SNDRV_PCM_FMTBIT_S8 | \
902 SNDRV_PCM_FMTBIT_S16_LE | \
903 SNDRV_PCM_FMTBIT_S18_3LE | \
904 SNDRV_PCM_FMTBIT_S20_3LE | \
905 SNDRV_PCM_FMTBIT_S24_3LE | \
906 SNDRV_PCM_FMTBIT_S24_LE | \
907 SNDRV_PCM_FMTBIT_S32_LE)
908
909static struct snd_soc_dai_driver mchp_i2s_mcc_dai = {
910 .playback = {
911 .stream_name = "I2SMCC-Playback",
912 .channels_min = 1,
913 .channels_max = 8,
914 .rates = MCHP_I2SMCC_RATES,
915 .formats = MCHP_I2SMCC_FORMATS,
916 },
917 .capture = {
918 .stream_name = "I2SMCC-Capture",
919 .channels_min = 1,
920 .channels_max = 8,
921 .rates = MCHP_I2SMCC_RATES,
922 .formats = MCHP_I2SMCC_FORMATS,
923 },
924 .ops = &mchp_i2s_mcc_dai_ops,
925 .symmetric_rate = 1,
926 .symmetric_sample_bits = 1,
927 .symmetric_channels = 1,
928};
929
930static const struct snd_soc_component_driver mchp_i2s_mcc_component = {
931 .name = "mchp-i2s-mcc",
932 .legacy_dai_naming = 1,
933};
934
935#ifdef CONFIG_OF
936static struct mchp_i2s_mcc_soc_data mchp_i2s_mcc_sam9x60 = {
937 .data_pin_pair_num = 1,
938};
939
940static struct mchp_i2s_mcc_soc_data mchp_i2s_mcc_sama7g5 = {
941 .data_pin_pair_num = 4,
942 .has_fifo = true,
943};
944
945static const struct of_device_id mchp_i2s_mcc_dt_ids[] = {
946 {
947 .compatible = "microchip,sam9x60-i2smcc",
948 .data = &mchp_i2s_mcc_sam9x60,
949 },
950 {
951 .compatible = "microchip,sama7g5-i2smcc",
952 .data = &mchp_i2s_mcc_sama7g5,
953 },
954 { /* sentinel */ }
955};
956MODULE_DEVICE_TABLE(of, mchp_i2s_mcc_dt_ids);
957#endif
958
959static int mchp_i2s_mcc_soc_data_parse(struct platform_device *pdev,
960 struct mchp_i2s_mcc_dev *dev)
961{
962 int err;
963
964 if (!dev->soc) {
965 dev_err(&pdev->dev, "failed to get soc data\n");
966 return -ENODEV;
967 }
968
969 if (dev->soc->data_pin_pair_num == 1)
970 return 0;
971
972 err = of_property_read_u8(np: pdev->dev.of_node, propname: "microchip,tdm-data-pair",
973 out_value: &dev->tdm_data_pair);
974 if (err < 0 && err != -EINVAL) {
975 dev_err(&pdev->dev,
976 "bad property data for 'microchip,tdm-data-pair': %d",
977 err);
978 return err;
979 }
980 if (err == -EINVAL) {
981 dev_info(&pdev->dev,
982 "'microchip,tdm-data-pair' not found; assuming DIN/DOUT 0 for TDM\n");
983 dev->tdm_data_pair = 0;
984 } else {
985 if (dev->tdm_data_pair > dev->soc->data_pin_pair_num - 1) {
986 dev_err(&pdev->dev,
987 "invalid value for 'microchip,tdm-data-pair': %d\n",
988 dev->tdm_data_pair);
989 return -EINVAL;
990 }
991 dev_dbg(&pdev->dev, "TMD format on DIN/DOUT %d pins\n",
992 dev->tdm_data_pair);
993 }
994
995 return 0;
996}
997
998static int mchp_i2s_mcc_probe(struct platform_device *pdev)
999{
1000 struct mchp_i2s_mcc_dev *dev;
1001 struct resource *mem;
1002 struct regmap *regmap;
1003 void __iomem *base;
1004 u32 version;
1005 int irq;
1006 int err;
1007
1008 dev = devm_kzalloc(dev: &pdev->dev, size: sizeof(*dev), GFP_KERNEL);
1009 if (!dev)
1010 return -ENOMEM;
1011
1012 base = devm_platform_get_and_ioremap_resource(pdev, index: 0, res: &mem);
1013 if (IS_ERR(ptr: base))
1014 return PTR_ERR(ptr: base);
1015
1016 regmap = devm_regmap_init_mmio(&pdev->dev, base,
1017 &mchp_i2s_mcc_regmap_config);
1018 if (IS_ERR(ptr: regmap))
1019 return PTR_ERR(ptr: regmap);
1020
1021 irq = platform_get_irq(pdev, 0);
1022 if (irq < 0)
1023 return irq;
1024
1025 err = devm_request_irq(dev: &pdev->dev, irq, handler: mchp_i2s_mcc_interrupt, irqflags: 0,
1026 devname: dev_name(dev: &pdev->dev), dev_id: dev);
1027 if (err)
1028 return err;
1029
1030 dev->pclk = devm_clk_get(dev: &pdev->dev, id: "pclk");
1031 if (IS_ERR(ptr: dev->pclk)) {
1032 err = PTR_ERR(ptr: dev->pclk);
1033 dev_err(&pdev->dev,
1034 "failed to get the peripheral clock: %d\n", err);
1035 return err;
1036 }
1037
1038 /* Get the optional generated clock */
1039 dev->gclk = devm_clk_get(dev: &pdev->dev, id: "gclk");
1040 if (IS_ERR(ptr: dev->gclk)) {
1041 if (PTR_ERR(ptr: dev->gclk) == -EPROBE_DEFER)
1042 return -EPROBE_DEFER;
1043 dev_warn(&pdev->dev,
1044 "generated clock not found: %d\n", err);
1045 dev->gclk = NULL;
1046 }
1047
1048 dev->soc = of_device_get_match_data(dev: &pdev->dev);
1049 err = mchp_i2s_mcc_soc_data_parse(pdev, dev);
1050 if (err < 0)
1051 return err;
1052
1053 dev->dev = &pdev->dev;
1054 dev->regmap = regmap;
1055 platform_set_drvdata(pdev, data: dev);
1056
1057 err = clk_prepare_enable(clk: dev->pclk);
1058 if (err) {
1059 dev_err(&pdev->dev,
1060 "failed to enable the peripheral clock: %d\n", err);
1061 return err;
1062 }
1063
1064 err = devm_snd_soc_register_component(dev: &pdev->dev,
1065 component_driver: &mchp_i2s_mcc_component,
1066 dai_drv: &mchp_i2s_mcc_dai, num_dai: 1);
1067 if (err) {
1068 dev_err(&pdev->dev, "failed to register DAI: %d\n", err);
1069 clk_disable_unprepare(clk: dev->pclk);
1070 return err;
1071 }
1072
1073 dev->playback.addr = (dma_addr_t)mem->start + MCHP_I2SMCC_THR;
1074 dev->capture.addr = (dma_addr_t)mem->start + MCHP_I2SMCC_RHR;
1075
1076 err = devm_snd_dmaengine_pcm_register(dev: &pdev->dev, NULL, flags: 0);
1077 if (err) {
1078 dev_err(&pdev->dev, "failed to register PCM: %d\n", err);
1079 clk_disable_unprepare(clk: dev->pclk);
1080 return err;
1081 }
1082
1083 /* Get IP version. */
1084 regmap_read(map: dev->regmap, MCHP_I2SMCC_VERSION, val: &version);
1085 dev_info(&pdev->dev, "hw version: %#lx\n",
1086 version & MCHP_I2SMCC_VERSION_MASK);
1087
1088 return 0;
1089}
1090
1091static void mchp_i2s_mcc_remove(struct platform_device *pdev)
1092{
1093 struct mchp_i2s_mcc_dev *dev = platform_get_drvdata(pdev);
1094
1095 clk_disable_unprepare(clk: dev->pclk);
1096}
1097
1098static struct platform_driver mchp_i2s_mcc_driver = {
1099 .driver = {
1100 .name = "mchp_i2s_mcc",
1101 .of_match_table = mchp_i2s_mcc_dt_ids,
1102 },
1103 .probe = mchp_i2s_mcc_probe,
1104 .remove_new = mchp_i2s_mcc_remove,
1105};
1106module_platform_driver(mchp_i2s_mcc_driver);
1107
1108MODULE_DESCRIPTION("Microchip I2S Multi-Channel Controller driver");
1109MODULE_AUTHOR("Codrin Ciubotariu <codrin.ciubotariu@microchip.com>");
1110MODULE_LICENSE("GPL v2");
1111

source code of linux/sound/soc/atmel/mchp-i2s-mcc.c