xref: /openbmc/linux/sound/soc/atmel/mchp-i2s-mcc.c (revision b830f94f)
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 
20 #include <sound/core.h>
21 #include <sound/pcm.h>
22 #include <sound/pcm_params.h>
23 #include <sound/initval.h>
24 #include <sound/soc.h>
25 #include <sound/dmaengine_pcm.h>
26 
27 /*
28  * ---- I2S Controller Register map ----
29  */
30 #define MCHP_I2SMCC_CR		0x0000	/* Control Register */
31 #define MCHP_I2SMCC_MRA		0x0004	/* Mode Register A */
32 #define MCHP_I2SMCC_MRB		0x0008	/* Mode Register B */
33 #define MCHP_I2SMCC_SR		0x000C	/* Status Register */
34 #define MCHP_I2SMCC_IERA	0x0010	/* Interrupt Enable Register A */
35 #define MCHP_I2SMCC_IDRA	0x0014	/* Interrupt Disable Register A */
36 #define MCHP_I2SMCC_IMRA	0x0018	/* Interrupt Mask Register A */
37 #define MCHP_I2SMCC_ISRA	0X001C	/* Interrupt Status Register A */
38 
39 #define MCHP_I2SMCC_IERB	0x0020	/* Interrupt Enable Register B */
40 #define MCHP_I2SMCC_IDRB	0x0024	/* Interrupt Disable Register B */
41 #define MCHP_I2SMCC_IMRB	0x0028	/* Interrupt Mask Register B */
42 #define MCHP_I2SMCC_ISRB	0X002C	/* Interrupt Status Register B */
43 
44 #define MCHP_I2SMCC_RHR		0x0030	/* Receiver Holding Register */
45 #define MCHP_I2SMCC_THR		0x0034	/* Transmitter Holding Register */
46 
47 #define MCHP_I2SMCC_RHL0R	0x0040	/* Receiver Holding Left 0 Register */
48 #define MCHP_I2SMCC_RHR0R	0x0044	/* Receiver Holding Right 0 Register */
49 
50 #define MCHP_I2SMCC_RHL1R	0x0048	/* Receiver Holding Left 1 Register */
51 #define MCHP_I2SMCC_RHR1R	0x004C	/* Receiver Holding Right 1 Register */
52 
53 #define MCHP_I2SMCC_RHL2R	0x0050	/* Receiver Holding Left 2 Register */
54 #define MCHP_I2SMCC_RHR2R	0x0054	/* Receiver Holding Right 2 Register */
55 
56 #define MCHP_I2SMCC_RHL3R	0x0058	/* Receiver Holding Left 3 Register */
57 #define MCHP_I2SMCC_RHR3R	0x005C	/* Receiver Holding Right 3 Register */
58 
59 #define MCHP_I2SMCC_THL0R	0x0060	/* Transmitter Holding Left 0 Register */
60 #define MCHP_I2SMCC_THR0R	0x0064	/* Transmitter Holding Right 0 Register */
61 
62 #define MCHP_I2SMCC_THL1R	0x0068	/* Transmitter Holding Left 1 Register */
63 #define MCHP_I2SMCC_THR1R	0x006C	/* Transmitter Holding Right 1 Register */
64 
65 #define MCHP_I2SMCC_THL2R	0x0070	/* Transmitter Holding Left 2 Register */
66 #define MCHP_I2SMCC_THR2R	0x0074	/* Transmitter Holding Right 2 Register */
67 
68 #define MCHP_I2SMCC_THL3R	0x0078	/* Transmitter Holding Left 3 Register */
69 #define MCHP_I2SMCC_THR3R	0x007C	/* Transmitter Holding Right 3 Register */
70 
71 #define MCHP_I2SMCC_VERSION	0x00FC	/* Version Register */
72 
73 /*
74  * ---- Control Register (Write-only) ----
75  */
76 #define MCHP_I2SMCC_CR_RXEN		BIT(0)	/* Receiver Enable */
77 #define MCHP_I2SMCC_CR_RXDIS		BIT(1)	/* Receiver Disable */
78 #define MCHP_I2SMCC_CR_CKEN		BIT(2)	/* Clock Enable */
79 #define MCHP_I2SMCC_CR_CKDIS		BIT(3)	/* Clock Disable */
80 #define MCHP_I2SMCC_CR_TXEN		BIT(4)	/* Transmitter Enable */
81 #define MCHP_I2SMCC_CR_TXDIS		BIT(5)	/* Transmitter Disable */
82 #define MCHP_I2SMCC_CR_SWRST		BIT(7)	/* Software Reset */
83 
84 /*
85  * ---- Mode Register A (Read/Write) ----
86  */
87 #define MCHP_I2SMCC_MRA_MODE_MASK		GENMASK(0, 0)
88 #define MCHP_I2SMCC_MRA_MODE_SLAVE		(0 << 0)
89 #define MCHP_I2SMCC_MRA_MODE_MASTER		(1 << 0)
90 
91 #define MCHP_I2SMCC_MRA_DATALENGTH_MASK			GENMASK(3, 1)
92 #define MCHP_I2SMCC_MRA_DATALENGTH_32_BITS		(0 << 1)
93 #define MCHP_I2SMCC_MRA_DATALENGTH_24_BITS		(1 << 1)
94 #define MCHP_I2SMCC_MRA_DATALENGTH_20_BITS		(2 << 1)
95 #define MCHP_I2SMCC_MRA_DATALENGTH_18_BITS		(3 << 1)
96 #define MCHP_I2SMCC_MRA_DATALENGTH_16_BITS		(4 << 1)
97 #define MCHP_I2SMCC_MRA_DATALENGTH_16_BITS_COMPACT	(5 << 1)
98 #define MCHP_I2SMCC_MRA_DATALENGTH_8_BITS		(6 << 1)
99 #define MCHP_I2SMCC_MRA_DATALENGTH_8_BITS_COMPACT	(7 << 1)
100 
101 #define MCHP_I2SMCC_MRA_WIRECFG_MASK		GENMASK(5, 4)
102 #define MCHP_I2SMCC_MRA_WIRECFG_I2S_1_TDM_0	(0 << 4)
103 #define MCHP_I2SMCC_MRA_WIRECFG_I2S_2_TDM_1	(1 << 4)
104 #define MCHP_I2SMCC_MRA_WIRECFG_I2S_4_TDM_2	(2 << 4)
105 #define MCHP_I2SMCC_MRA_WIRECFG_TDM_3		(3 << 4)
106 
107 #define MCHP_I2SMCC_MRA_FORMAT_MASK		GENMASK(7, 6)
108 #define MCHP_I2SMCC_MRA_FORMAT_I2S		(0 << 6)
109 #define MCHP_I2SMCC_MRA_FORMAT_LJ		(1 << 6) /* Left Justified */
110 #define MCHP_I2SMCC_MRA_FORMAT_TDM		(2 << 6)
111 #define MCHP_I2SMCC_MRA_FORMAT_TDMLJ		(3 << 6)
112 
113 /* Transmitter uses one DMA channel ... */
114 /* Left audio samples duplicated to right audio channel */
115 #define MCHP_I2SMCC_MRA_RXMONO			BIT(8)
116 
117 /* I2SDO output of I2SC is internally connected to I2SDI input */
118 #define MCHP_I2SMCC_MRA_RXLOOP			BIT(9)
119 
120 /* Receiver uses one DMA channel ... */
121 /* Left audio samples duplicated to right audio channel */
122 #define MCHP_I2SMCC_MRA_TXMONO			BIT(10)
123 
124 /* x sample transmitted when underrun */
125 #define MCHP_I2SMCC_MRA_TXSAME_ZERO		(0 << 11) /* Zero sample */
126 #define MCHP_I2SMCC_MRA_TXSAME_PREVIOUS		(1 << 11) /* Previous sample */
127 
128 /* select between peripheral clock and generated clock */
129 #define MCHP_I2SMCC_MRA_SRCCLK_PCLK		(0 << 12)
130 #define MCHP_I2SMCC_MRA_SRCCLK_GCLK		(1 << 12)
131 
132 /* Number of TDM Channels - 1 */
133 #define MCHP_I2SMCC_MRA_NBCHAN_MASK		GENMASK(15, 13)
134 #define MCHP_I2SMCC_MRA_NBCHAN(ch) \
135 	((((ch) - 1) << 13) & MCHP_I2SMCC_MRA_NBCHAN_MASK)
136 
137 /* Selected Clock to I2SMCC Master Clock ratio */
138 #define MCHP_I2SMCC_MRA_IMCKDIV_MASK		GENMASK(21, 16)
139 #define MCHP_I2SMCC_MRA_IMCKDIV(div) \
140 	(((div) << 16) & MCHP_I2SMCC_MRA_IMCKDIV_MASK)
141 
142 /* TDM Frame Synchronization */
143 #define MCHP_I2SMCC_MRA_TDMFS_MASK		GENMASK(23, 22)
144 #define MCHP_I2SMCC_MRA_TDMFS_SLOT		(0 << 22)
145 #define MCHP_I2SMCC_MRA_TDMFS_HALF		(1 << 22)
146 #define MCHP_I2SMCC_MRA_TDMFS_BIT		(2 << 22)
147 
148 /* Selected Clock to I2SMC Serial Clock ratio */
149 #define MCHP_I2SMCC_MRA_ISCKDIV_MASK		GENMASK(29, 24)
150 #define MCHP_I2SMCC_MRA_ISCKDIV(div) \
151 	(((div) << 24) & MCHP_I2SMCC_MRA_ISCKDIV_MASK)
152 
153 /* Master Clock mode */
154 #define MCHP_I2SMCC_MRA_IMCKMODE_MASK		GENMASK(30, 30)
155 /* 0: No master clock generated*/
156 #define MCHP_I2SMCC_MRA_IMCKMODE_NONE		(0 << 30)
157 /* 1: master clock generated (internally generated clock drives I2SMCK pin) */
158 #define MCHP_I2SMCC_MRA_IMCKMODE_GEN		(1 << 30)
159 
160 /* Slot Width */
161 /* 0: slot is 32 bits wide for DATALENGTH = 18/20/24 bits. */
162 /* 1: slot is 24 bits wide for DATALENGTH = 18/20/24 bits. */
163 #define MCHP_I2SMCC_MRA_IWS			BIT(31)
164 
165 /*
166  * ---- Mode Register B (Read/Write) ----
167  */
168 /* all enabled I2S left channels are filled first, then I2S right channels */
169 #define MCHP_I2SMCC_MRB_CRAMODE_LEFT_FIRST	(0 << 0)
170 /*
171  * an enabled I2S left channel is filled, then the corresponding right
172  * channel, until all channels are filled
173  */
174 #define MCHP_I2SMCC_MRB_CRAMODE_REGULAR		(1 << 0)
175 
176 #define MCHP_I2SMCC_MRB_FIFOEN			BIT(1)
177 
178 #define MCHP_I2SMCC_MRB_DMACHUNK_MASK		GENMASK(9, 8)
179 #define MCHP_I2SMCC_MRB_DMACHUNK(no_words) \
180 	(((fls(no_words) - 1) << 8) & MCHP_I2SMCC_MRB_DMACHUNK_MASK)
181 
182 #define MCHP_I2SMCC_MRB_CLKSEL_MASK		GENMASK(16, 16)
183 #define MCHP_I2SMCC_MRB_CLKSEL_EXT		(0 << 16)
184 #define MCHP_I2SMCC_MRB_CLKSEL_INT		(1 << 16)
185 
186 /*
187  * ---- Status Registers (Read-only) ----
188  */
189 #define MCHP_I2SMCC_SR_RXEN		BIT(0)	/* Receiver Enabled */
190 #define MCHP_I2SMCC_SR_TXEN		BIT(4)	/* Transmitter Enabled */
191 
192 /*
193  * ---- Interrupt Enable/Disable/Mask/Status Registers A ----
194  */
195 #define MCHP_I2SMCC_INT_TXRDY_MASK(ch)		GENMASK((ch) - 1, 0)
196 #define MCHP_I2SMCC_INT_TXRDYCH(ch)		BIT(ch)
197 #define MCHP_I2SMCC_INT_TXUNF_MASK(ch)		GENMASK((ch) + 7, 8)
198 #define MCHP_I2SMCC_INT_TXUNFCH(ch)		BIT((ch) + 8)
199 #define MCHP_I2SMCC_INT_RXRDY_MASK(ch)		GENMASK((ch) + 15, 16)
200 #define MCHP_I2SMCC_INT_RXRDYCH(ch)		BIT((ch) + 16)
201 #define MCHP_I2SMCC_INT_RXOVF_MASK(ch)		GENMASK((ch) + 23, 24)
202 #define MCHP_I2SMCC_INT_RXOVFCH(ch)		BIT((ch) + 24)
203 
204 /*
205  * ---- Interrupt Enable/Disable/Mask/Status Registers B ----
206  */
207 #define MCHP_I2SMCC_INT_WERR			BIT(0)
208 #define MCHP_I2SMCC_INT_TXFFRDY			BIT(8)
209 #define MCHP_I2SMCC_INT_TXFFEMP			BIT(9)
210 #define MCHP_I2SMCC_INT_RXFFRDY			BIT(12)
211 #define MCHP_I2SMCC_INT_RXFFFUL			BIT(13)
212 
213 /*
214  * ---- Version Register (Read-only) ----
215  */
216 #define MCHP_I2SMCC_VERSION_MASK		GENMASK(11, 0)
217 
218 #define MCHP_I2SMCC_MAX_CHANNELS		8
219 #define MCHP_I2MCC_TDM_SLOT_WIDTH		32
220 
221 static const struct regmap_config mchp_i2s_mcc_regmap_config = {
222 	.reg_bits = 32,
223 	.reg_stride = 4,
224 	.val_bits = 32,
225 	.max_register = MCHP_I2SMCC_VERSION,
226 };
227 
228 struct mchp_i2s_mcc_dev {
229 	struct wait_queue_head			wq_txrdy;
230 	struct wait_queue_head			wq_rxrdy;
231 	struct device				*dev;
232 	struct regmap				*regmap;
233 	struct clk				*pclk;
234 	struct clk				*gclk;
235 	struct snd_dmaengine_dai_dma_data	playback;
236 	struct snd_dmaengine_dai_dma_data	capture;
237 	unsigned int				fmt;
238 	unsigned int				sysclk;
239 	unsigned int				frame_length;
240 	int					tdm_slots;
241 	int					channels;
242 	int					gclk_use:1;
243 	int					gclk_running:1;
244 	int					tx_rdy:1;
245 	int					rx_rdy:1;
246 };
247 
248 static irqreturn_t mchp_i2s_mcc_interrupt(int irq, void *dev_id)
249 {
250 	struct mchp_i2s_mcc_dev *dev = dev_id;
251 	u32 sra, imra, srb, imrb, pendinga, pendingb, idra = 0;
252 	irqreturn_t ret = IRQ_NONE;
253 
254 	regmap_read(dev->regmap, MCHP_I2SMCC_IMRA, &imra);
255 	regmap_read(dev->regmap, MCHP_I2SMCC_ISRA, &sra);
256 	pendinga = imra & sra;
257 
258 	regmap_read(dev->regmap, MCHP_I2SMCC_IMRB, &imrb);
259 	regmap_read(dev->regmap, MCHP_I2SMCC_ISRB, &srb);
260 	pendingb = imrb & srb;
261 
262 	if (!pendinga && !pendingb)
263 		return IRQ_NONE;
264 
265 	/*
266 	 * Tx/Rx ready interrupts are enabled when stopping only, to assure
267 	 * availability and to disable clocks if necessary
268 	 */
269 	idra |= pendinga & (MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels) |
270 			    MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels));
271 	if (idra)
272 		ret = IRQ_HANDLED;
273 
274 	if ((imra & MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels)) &&
275 	    (imra & MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels)) ==
276 	    (idra & MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels))) {
277 		dev->tx_rdy = 1;
278 		wake_up_interruptible(&dev->wq_txrdy);
279 	}
280 	if ((imra & MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels)) &&
281 	    (imra & MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels)) ==
282 	    (idra & MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels))) {
283 		dev->rx_rdy = 1;
284 		wake_up_interruptible(&dev->wq_rxrdy);
285 	}
286 	regmap_write(dev->regmap, MCHP_I2SMCC_IDRA, idra);
287 
288 	return ret;
289 }
290 
291 static int mchp_i2s_mcc_set_sysclk(struct snd_soc_dai *dai,
292 				   int clk_id, unsigned int freq, int dir)
293 {
294 	struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai);
295 
296 	dev_dbg(dev->dev, "%s() clk_id=%d freq=%u dir=%d\n",
297 		__func__, clk_id, freq, dir);
298 
299 	/* We do not need SYSCLK */
300 	if (dir == SND_SOC_CLOCK_IN)
301 		return 0;
302 
303 	dev->sysclk = freq;
304 
305 	return 0;
306 }
307 
308 static int mchp_i2s_mcc_set_bclk_ratio(struct snd_soc_dai *dai,
309 				       unsigned int ratio)
310 {
311 	struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai);
312 
313 	dev_dbg(dev->dev, "%s() ratio=%u\n", __func__, ratio);
314 
315 	dev->frame_length = ratio;
316 
317 	return 0;
318 }
319 
320 static int mchp_i2s_mcc_set_dai_fmt(struct snd_soc_dai *dai, unsigned int fmt)
321 {
322 	struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai);
323 
324 	dev_dbg(dev->dev, "%s() fmt=%#x\n", __func__, fmt);
325 
326 	/* We don't support any kind of clock inversion */
327 	if ((fmt & SND_SOC_DAIFMT_INV_MASK) != SND_SOC_DAIFMT_NB_NF)
328 		return -EINVAL;
329 
330 	/* We can't generate only FSYNC */
331 	if ((fmt & SND_SOC_DAIFMT_MASTER_MASK) == SND_SOC_DAIFMT_CBM_CFS)
332 		return -EINVAL;
333 
334 	/* We can only reconfigure the IP when it's stopped */
335 	if (fmt & SND_SOC_DAIFMT_CONT)
336 		return -EINVAL;
337 
338 	dev->fmt = fmt;
339 
340 	return 0;
341 }
342 
343 static int mchp_i2s_mcc_set_dai_tdm_slot(struct snd_soc_dai *dai,
344 					 unsigned int tx_mask,
345 					 unsigned int rx_mask,
346 					 int slots, int slot_width)
347 {
348 	struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai);
349 
350 	dev_dbg(dev->dev,
351 		"%s() tx_mask=0x%08x rx_mask=0x%08x slots=%d width=%d\n",
352 		__func__, tx_mask, rx_mask, slots, slot_width);
353 
354 	if (slots < 0 || slots > MCHP_I2SMCC_MAX_CHANNELS ||
355 	    slot_width != MCHP_I2MCC_TDM_SLOT_WIDTH)
356 		return -EINVAL;
357 
358 	if (slots) {
359 		/* We do not support daisy chain */
360 		if (rx_mask != GENMASK(slots - 1, 0) ||
361 		    rx_mask != tx_mask)
362 			return -EINVAL;
363 	}
364 
365 	dev->tdm_slots = slots;
366 	dev->frame_length = slots * MCHP_I2MCC_TDM_SLOT_WIDTH;
367 
368 	return 0;
369 }
370 
371 static int mchp_i2s_mcc_clk_get_rate_diff(struct clk *clk,
372 					  unsigned long rate,
373 					  struct clk **best_clk,
374 					  unsigned long *best_rate,
375 					  unsigned long *best_diff_rate)
376 {
377 	long round_rate;
378 	unsigned int diff_rate;
379 
380 	round_rate = clk_round_rate(clk, rate);
381 	if (round_rate < 0)
382 		return (int)round_rate;
383 
384 	diff_rate = abs(rate - round_rate);
385 	if (diff_rate < *best_diff_rate) {
386 		*best_clk = clk;
387 		*best_diff_rate = diff_rate;
388 		*best_rate = rate;
389 	}
390 
391 	return 0;
392 }
393 
394 static int mchp_i2s_mcc_config_divs(struct mchp_i2s_mcc_dev *dev,
395 				    unsigned int bclk, unsigned int *mra)
396 {
397 	unsigned long clk_rate;
398 	unsigned long lcm_rate;
399 	unsigned long best_rate = 0;
400 	unsigned long best_diff_rate = ~0;
401 	unsigned int sysclk;
402 	struct clk *best_clk = NULL;
403 	int ret;
404 
405 	/* For code simplification */
406 	if (!dev->sysclk)
407 		sysclk = bclk;
408 	else
409 		sysclk = dev->sysclk;
410 
411 	/*
412 	 * MCLK is Selected CLK / (2 * IMCKDIV),
413 	 * BCLK is Selected CLK / (2 * ISCKDIV);
414 	 * if IMCKDIV or ISCKDIV are 0, MCLK or BCLK = Selected CLK
415 	 */
416 	lcm_rate = lcm(sysclk, bclk);
417 	if ((lcm_rate / sysclk % 2 == 1 && lcm_rate / sysclk > 2) ||
418 	    (lcm_rate / bclk % 2 == 1 && lcm_rate / bclk > 2))
419 		lcm_rate *= 2;
420 
421 	for (clk_rate = lcm_rate;
422 	     (clk_rate == sysclk || clk_rate / (sysclk * 2) <= GENMASK(5, 0)) &&
423 	     (clk_rate == bclk || clk_rate / (bclk * 2) <= GENMASK(5, 0));
424 	     clk_rate += lcm_rate) {
425 		ret = mchp_i2s_mcc_clk_get_rate_diff(dev->gclk, clk_rate,
426 						     &best_clk, &best_rate,
427 						     &best_diff_rate);
428 		if (ret) {
429 			dev_err(dev->dev, "gclk error for rate %lu: %d",
430 				clk_rate, ret);
431 		} else {
432 			if (!best_diff_rate) {
433 				dev_dbg(dev->dev, "found perfect rate on gclk: %lu\n",
434 					clk_rate);
435 				break;
436 			}
437 		}
438 
439 		ret = mchp_i2s_mcc_clk_get_rate_diff(dev->pclk, clk_rate,
440 						     &best_clk, &best_rate,
441 						     &best_diff_rate);
442 		if (ret) {
443 			dev_err(dev->dev, "pclk error for rate %lu: %d",
444 				clk_rate, ret);
445 		} else {
446 			if (!best_diff_rate) {
447 				dev_dbg(dev->dev, "found perfect rate on pclk: %lu\n",
448 					clk_rate);
449 				break;
450 			}
451 		}
452 	}
453 
454 	/* check if clocks returned only errors */
455 	if (!best_clk) {
456 		dev_err(dev->dev, "unable to change rate to clocks\n");
457 		return -EINVAL;
458 	}
459 
460 	dev_dbg(dev->dev, "source CLK is %s with rate %lu, diff %lu\n",
461 		best_clk == dev->pclk ? "pclk" : "gclk",
462 		best_rate, best_diff_rate);
463 
464 	/* set the rate */
465 	ret = clk_set_rate(best_clk, best_rate);
466 	if (ret) {
467 		dev_err(dev->dev, "unable to set rate %lu to %s: %d\n",
468 			best_rate, best_clk == dev->pclk ? "PCLK" : "GCLK",
469 			ret);
470 		return ret;
471 	}
472 
473 	/* Configure divisors */
474 	if (dev->sysclk)
475 		*mra |= MCHP_I2SMCC_MRA_IMCKDIV(best_rate / (2 * sysclk));
476 	*mra |= MCHP_I2SMCC_MRA_ISCKDIV(best_rate / (2 * bclk));
477 
478 	if (best_clk == dev->gclk) {
479 		*mra |= MCHP_I2SMCC_MRA_SRCCLK_GCLK;
480 		ret = clk_prepare(dev->gclk);
481 		if (ret < 0)
482 			dev_err(dev->dev, "unable to prepare GCLK: %d\n", ret);
483 		else
484 			dev->gclk_use = 1;
485 	} else {
486 		*mra |= MCHP_I2SMCC_MRA_SRCCLK_PCLK;
487 		dev->gclk_use = 0;
488 	}
489 
490 	return 0;
491 }
492 
493 static int mchp_i2s_mcc_is_running(struct mchp_i2s_mcc_dev *dev)
494 {
495 	u32 sr;
496 
497 	regmap_read(dev->regmap, MCHP_I2SMCC_SR, &sr);
498 	return !!(sr & (MCHP_I2SMCC_SR_TXEN | MCHP_I2SMCC_SR_RXEN));
499 }
500 
501 static int mchp_i2s_mcc_hw_params(struct snd_pcm_substream *substream,
502 				  struct snd_pcm_hw_params *params,
503 				  struct snd_soc_dai *dai)
504 {
505 	struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai);
506 	u32 mra = 0;
507 	u32 mrb = 0;
508 	unsigned int channels = params_channels(params);
509 	unsigned int frame_length = dev->frame_length;
510 	unsigned int bclk_rate;
511 	int set_divs = 0;
512 	int ret;
513 	bool is_playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
514 
515 	dev_dbg(dev->dev, "%s() rate=%u format=%#x width=%u channels=%u\n",
516 		__func__, params_rate(params), params_format(params),
517 		params_width(params), params_channels(params));
518 
519 	switch (dev->fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
520 	case SND_SOC_DAIFMT_I2S:
521 		if (dev->tdm_slots) {
522 			dev_err(dev->dev, "I2S with TDM is not supported\n");
523 			return -EINVAL;
524 		}
525 		mra |= MCHP_I2SMCC_MRA_FORMAT_I2S;
526 		break;
527 	case SND_SOC_DAIFMT_LEFT_J:
528 		if (dev->tdm_slots) {
529 			dev_err(dev->dev, "Left-Justified with TDM is not supported\n");
530 			return -EINVAL;
531 		}
532 		mra |= MCHP_I2SMCC_MRA_FORMAT_LJ;
533 		break;
534 	case SND_SOC_DAIFMT_DSP_A:
535 		mra |= MCHP_I2SMCC_MRA_FORMAT_TDM;
536 		break;
537 	default:
538 		dev_err(dev->dev, "unsupported bus format\n");
539 		return -EINVAL;
540 	}
541 
542 	switch (dev->fmt & SND_SOC_DAIFMT_MASTER_MASK) {
543 	case SND_SOC_DAIFMT_CBS_CFS:
544 		/* cpu is BCLK and LRC master */
545 		mra |= MCHP_I2SMCC_MRA_MODE_MASTER;
546 		if (dev->sysclk)
547 			mra |= MCHP_I2SMCC_MRA_IMCKMODE_GEN;
548 		set_divs = 1;
549 		break;
550 	case SND_SOC_DAIFMT_CBS_CFM:
551 		/* cpu is BCLK master */
552 		mrb |= MCHP_I2SMCC_MRB_CLKSEL_INT;
553 		set_divs = 1;
554 		/* fall through */
555 	case SND_SOC_DAIFMT_CBM_CFM:
556 		/* cpu is slave */
557 		mra |= MCHP_I2SMCC_MRA_MODE_SLAVE;
558 		if (dev->sysclk)
559 			dev_warn(dev->dev, "Unable to generate MCLK in Slave mode\n");
560 		break;
561 	default:
562 		dev_err(dev->dev, "unsupported master/slave mode\n");
563 		return -EINVAL;
564 	}
565 
566 	if (dev->fmt & (SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_LEFT_J)) {
567 		switch (channels) {
568 		case 1:
569 			if (is_playback)
570 				mra |= MCHP_I2SMCC_MRA_TXMONO;
571 			else
572 				mra |= MCHP_I2SMCC_MRA_RXMONO;
573 			break;
574 		case 2:
575 			break;
576 		default:
577 			dev_err(dev->dev, "unsupported number of audio channels\n");
578 			return -EINVAL;
579 		}
580 
581 		if (!frame_length)
582 			frame_length = 2 * params_physical_width(params);
583 	} else if (dev->fmt & SND_SOC_DAIFMT_DSP_A) {
584 		if (dev->tdm_slots) {
585 			if (channels % 2 && channels * 2 <= dev->tdm_slots) {
586 				/*
587 				 * Duplicate data for even-numbered channels
588 				 * to odd-numbered channels
589 				 */
590 				if (is_playback)
591 					mra |= MCHP_I2SMCC_MRA_TXMONO;
592 				else
593 					mra |= MCHP_I2SMCC_MRA_RXMONO;
594 			}
595 			channels = dev->tdm_slots;
596 		}
597 
598 		mra |= MCHP_I2SMCC_MRA_NBCHAN(channels);
599 		if (!frame_length)
600 			frame_length = channels * MCHP_I2MCC_TDM_SLOT_WIDTH;
601 	}
602 
603 	/*
604 	 * We must have the same burst size configured
605 	 * in the DMA transfer and in out IP
606 	 */
607 	mrb |= MCHP_I2SMCC_MRB_DMACHUNK(channels);
608 	if (is_playback)
609 		dev->playback.maxburst = 1 << (fls(channels) - 1);
610 	else
611 		dev->capture.maxburst = 1 << (fls(channels) - 1);
612 
613 	switch (params_format(params)) {
614 	case SNDRV_PCM_FORMAT_S8:
615 		mra |= MCHP_I2SMCC_MRA_DATALENGTH_8_BITS;
616 		break;
617 	case SNDRV_PCM_FORMAT_S16_LE:
618 		mra |= MCHP_I2SMCC_MRA_DATALENGTH_16_BITS;
619 		break;
620 	case SNDRV_PCM_FORMAT_S18_3LE:
621 		mra |= MCHP_I2SMCC_MRA_DATALENGTH_18_BITS |
622 		       MCHP_I2SMCC_MRA_IWS;
623 		break;
624 	case SNDRV_PCM_FORMAT_S20_3LE:
625 		mra |= MCHP_I2SMCC_MRA_DATALENGTH_20_BITS |
626 		       MCHP_I2SMCC_MRA_IWS;
627 		break;
628 	case SNDRV_PCM_FORMAT_S24_3LE:
629 		mra |= MCHP_I2SMCC_MRA_DATALENGTH_24_BITS |
630 		       MCHP_I2SMCC_MRA_IWS;
631 		break;
632 	case SNDRV_PCM_FORMAT_S24_LE:
633 		mra |= MCHP_I2SMCC_MRA_DATALENGTH_24_BITS;
634 		break;
635 	case SNDRV_PCM_FORMAT_S32_LE:
636 		mra |= MCHP_I2SMCC_MRA_DATALENGTH_32_BITS;
637 		break;
638 	default:
639 		dev_err(dev->dev, "unsupported size/endianness for audio samples\n");
640 		return -EINVAL;
641 	}
642 
643 	/*
644 	 * If we are already running, the wanted setup must be
645 	 * the same with the one that's currently ongoing
646 	 */
647 	if (mchp_i2s_mcc_is_running(dev)) {
648 		u32 mra_cur;
649 		u32 mrb_cur;
650 
651 		regmap_read(dev->regmap, MCHP_I2SMCC_MRA, &mra_cur);
652 		regmap_read(dev->regmap, MCHP_I2SMCC_MRB, &mrb_cur);
653 		if (mra != mra_cur || mrb != mrb_cur)
654 			return -EINVAL;
655 
656 		return 0;
657 	}
658 
659 	/* Save the number of channels to know what interrupts to enable */
660 	dev->channels = channels;
661 
662 	if (set_divs) {
663 		bclk_rate = frame_length * params_rate(params);
664 		ret = mchp_i2s_mcc_config_divs(dev, bclk_rate, &mra);
665 		if (ret) {
666 			dev_err(dev->dev, "unable to configure the divisors: %d\n",
667 				ret);
668 			return ret;
669 		}
670 	}
671 
672 	ret = regmap_write(dev->regmap, MCHP_I2SMCC_MRA, mra);
673 	if (ret < 0)
674 		return ret;
675 	return regmap_write(dev->regmap, MCHP_I2SMCC_MRB, mrb);
676 }
677 
678 static int mchp_i2s_mcc_hw_free(struct snd_pcm_substream *substream,
679 				struct snd_soc_dai *dai)
680 {
681 	struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai);
682 	bool is_playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
683 	long err;
684 
685 	if (is_playback) {
686 		err = wait_event_interruptible_timeout(dev->wq_txrdy,
687 						       dev->tx_rdy,
688 						       msecs_to_jiffies(500));
689 	} else {
690 		err = wait_event_interruptible_timeout(dev->wq_rxrdy,
691 						       dev->rx_rdy,
692 						       msecs_to_jiffies(500));
693 	}
694 
695 	if (err == 0) {
696 		u32 idra;
697 
698 		dev_warn_once(dev->dev, "Timeout waiting for %s\n",
699 			      is_playback ? "Tx ready" : "Rx ready");
700 		if (is_playback)
701 			idra = MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels);
702 		else
703 			idra = MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels);
704 		regmap_write(dev->regmap, MCHP_I2SMCC_IDRA, idra);
705 	}
706 
707 	if (!mchp_i2s_mcc_is_running(dev)) {
708 		regmap_write(dev->regmap, MCHP_I2SMCC_CR, MCHP_I2SMCC_CR_CKDIS);
709 
710 		if (dev->gclk_running) {
711 			clk_disable_unprepare(dev->gclk);
712 			dev->gclk_running = 0;
713 		}
714 	}
715 
716 	return 0;
717 }
718 
719 static int mchp_i2s_mcc_trigger(struct snd_pcm_substream *substream, int cmd,
720 				struct snd_soc_dai *dai)
721 {
722 	struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai);
723 	bool is_playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
724 	u32 cr = 0;
725 	u32 iera = 0;
726 	u32 sr;
727 	int err;
728 
729 	switch (cmd) {
730 	case SNDRV_PCM_TRIGGER_START:
731 	case SNDRV_PCM_TRIGGER_RESUME:
732 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
733 		if (is_playback)
734 			cr = MCHP_I2SMCC_CR_TXEN | MCHP_I2SMCC_CR_CKEN;
735 		else
736 			cr = MCHP_I2SMCC_CR_RXEN | MCHP_I2SMCC_CR_CKEN;
737 		break;
738 	case SNDRV_PCM_TRIGGER_STOP:
739 	case SNDRV_PCM_TRIGGER_SUSPEND:
740 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
741 		regmap_read(dev->regmap, MCHP_I2SMCC_SR, &sr);
742 		if (is_playback && (sr & MCHP_I2SMCC_SR_TXEN)) {
743 			cr = MCHP_I2SMCC_CR_TXDIS;
744 			dev->tx_rdy = 0;
745 			/*
746 			 * Enable Tx Ready interrupts on all channels
747 			 * to assure all data is sent
748 			 */
749 			iera = MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels);
750 		} else if (!is_playback && (sr & MCHP_I2SMCC_SR_RXEN)) {
751 			cr = MCHP_I2SMCC_CR_RXDIS;
752 			dev->rx_rdy = 0;
753 			/*
754 			 * Enable Rx Ready interrupts on all channels
755 			 * to assure all data is received
756 			 */
757 			iera = MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels);
758 		}
759 		break;
760 	default:
761 		return -EINVAL;
762 	}
763 
764 	if ((cr & MCHP_I2SMCC_CR_CKEN) && dev->gclk_use &&
765 	    !dev->gclk_running) {
766 		err = clk_enable(dev->gclk);
767 		if (err) {
768 			dev_err_once(dev->dev, "failed to enable GCLK: %d\n",
769 				     err);
770 		} else {
771 			dev->gclk_running = 1;
772 		}
773 	}
774 
775 	regmap_write(dev->regmap, MCHP_I2SMCC_IERA, iera);
776 	regmap_write(dev->regmap, MCHP_I2SMCC_CR, cr);
777 
778 	return 0;
779 }
780 
781 static int mchp_i2s_mcc_startup(struct snd_pcm_substream *substream,
782 				struct snd_soc_dai *dai)
783 {
784 	struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai);
785 
786 	/* Software reset the IP if it's not running */
787 	if (!mchp_i2s_mcc_is_running(dev)) {
788 		return regmap_write(dev->regmap, MCHP_I2SMCC_CR,
789 				    MCHP_I2SMCC_CR_SWRST);
790 	}
791 
792 	return 0;
793 }
794 
795 static const struct snd_soc_dai_ops mchp_i2s_mcc_dai_ops = {
796 	.set_sysclk	= mchp_i2s_mcc_set_sysclk,
797 	.set_bclk_ratio = mchp_i2s_mcc_set_bclk_ratio,
798 	.startup	= mchp_i2s_mcc_startup,
799 	.trigger	= mchp_i2s_mcc_trigger,
800 	.hw_params	= mchp_i2s_mcc_hw_params,
801 	.hw_free	= mchp_i2s_mcc_hw_free,
802 	.set_fmt	= mchp_i2s_mcc_set_dai_fmt,
803 	.set_tdm_slot	= mchp_i2s_mcc_set_dai_tdm_slot,
804 };
805 
806 static int mchp_i2s_mcc_dai_probe(struct snd_soc_dai *dai)
807 {
808 	struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai);
809 
810 	init_waitqueue_head(&dev->wq_txrdy);
811 	init_waitqueue_head(&dev->wq_rxrdy);
812 
813 	snd_soc_dai_init_dma_data(dai, &dev->playback, &dev->capture);
814 
815 	return 0;
816 }
817 
818 #define MCHP_I2SMCC_RATES              SNDRV_PCM_RATE_8000_192000
819 
820 #define MCHP_I2SMCC_FORMATS	(SNDRV_PCM_FMTBIT_S8 |          \
821 				 SNDRV_PCM_FMTBIT_S16_LE |      \
822 				 SNDRV_PCM_FMTBIT_S18_3LE |     \
823 				 SNDRV_PCM_FMTBIT_S20_3LE |     \
824 				 SNDRV_PCM_FMTBIT_S24_3LE |     \
825 				 SNDRV_PCM_FMTBIT_S24_LE |      \
826 				 SNDRV_PCM_FMTBIT_S32_LE)
827 
828 static struct snd_soc_dai_driver mchp_i2s_mcc_dai = {
829 	.probe	= mchp_i2s_mcc_dai_probe,
830 	.playback = {
831 		.stream_name = "I2SMCC-Playback",
832 		.channels_min = 1,
833 		.channels_max = 8,
834 		.rates = MCHP_I2SMCC_RATES,
835 		.formats = MCHP_I2SMCC_FORMATS,
836 	},
837 	.capture = {
838 		.stream_name = "I2SMCC-Capture",
839 		.channels_min = 1,
840 		.channels_max = 8,
841 		.rates = MCHP_I2SMCC_RATES,
842 		.formats = MCHP_I2SMCC_FORMATS,
843 	},
844 	.ops = &mchp_i2s_mcc_dai_ops,
845 	.symmetric_rates = 1,
846 	.symmetric_samplebits = 1,
847 	.symmetric_channels = 1,
848 };
849 
850 static const struct snd_soc_component_driver mchp_i2s_mcc_component = {
851 	.name	= "mchp-i2s-mcc",
852 };
853 
854 #ifdef CONFIG_OF
855 static const struct of_device_id mchp_i2s_mcc_dt_ids[] = {
856 	{
857 		.compatible = "microchip,sam9x60-i2smcc",
858 	},
859 	{ /* sentinel */ }
860 };
861 MODULE_DEVICE_TABLE(of, mchp_i2s_mcc_dt_ids);
862 #endif
863 
864 static int mchp_i2s_mcc_probe(struct platform_device *pdev)
865 {
866 	struct mchp_i2s_mcc_dev *dev;
867 	struct resource *mem;
868 	struct regmap *regmap;
869 	void __iomem *base;
870 	u32 version;
871 	int irq;
872 	int err;
873 
874 	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
875 	if (!dev)
876 		return -ENOMEM;
877 
878 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
879 	base = devm_ioremap_resource(&pdev->dev, mem);
880 	if (IS_ERR(base))
881 		return PTR_ERR(base);
882 
883 	regmap = devm_regmap_init_mmio(&pdev->dev, base,
884 				       &mchp_i2s_mcc_regmap_config);
885 	if (IS_ERR(regmap))
886 		return PTR_ERR(regmap);
887 
888 	irq = platform_get_irq(pdev, 0);
889 	if (irq < 0)
890 		return irq;
891 
892 	err = devm_request_irq(&pdev->dev, irq, mchp_i2s_mcc_interrupt, 0,
893 			       dev_name(&pdev->dev), dev);
894 	if (err)
895 		return err;
896 
897 	dev->pclk = devm_clk_get(&pdev->dev, "pclk");
898 	if (IS_ERR(dev->pclk)) {
899 		err = PTR_ERR(dev->pclk);
900 		dev_err(&pdev->dev,
901 			"failed to get the peripheral clock: %d\n", err);
902 		return err;
903 	}
904 
905 	/* Get the optional generated clock */
906 	dev->gclk = devm_clk_get(&pdev->dev, "gclk");
907 	if (IS_ERR(dev->gclk)) {
908 		if (PTR_ERR(dev->gclk) == -EPROBE_DEFER)
909 			return -EPROBE_DEFER;
910 		dev_warn(&pdev->dev,
911 			 "generated clock not found: %d\n", err);
912 		dev->gclk = NULL;
913 	}
914 
915 	dev->dev = &pdev->dev;
916 	dev->regmap = regmap;
917 	platform_set_drvdata(pdev, dev);
918 
919 	err = clk_prepare_enable(dev->pclk);
920 	if (err) {
921 		dev_err(&pdev->dev,
922 			"failed to enable the peripheral clock: %d\n", err);
923 		return err;
924 	}
925 
926 	err = devm_snd_soc_register_component(&pdev->dev,
927 					      &mchp_i2s_mcc_component,
928 					      &mchp_i2s_mcc_dai, 1);
929 	if (err) {
930 		dev_err(&pdev->dev, "failed to register DAI: %d\n", err);
931 		clk_disable_unprepare(dev->pclk);
932 		return err;
933 	}
934 
935 	dev->playback.addr	= (dma_addr_t)mem->start + MCHP_I2SMCC_THR;
936 	dev->capture.addr	= (dma_addr_t)mem->start + MCHP_I2SMCC_RHR;
937 
938 	err = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
939 	if (err) {
940 		dev_err(&pdev->dev, "failed to register PCM: %d\n", err);
941 		clk_disable_unprepare(dev->pclk);
942 		return err;
943 	}
944 
945 	/* Get IP version. */
946 	regmap_read(dev->regmap, MCHP_I2SMCC_VERSION, &version);
947 	dev_info(&pdev->dev, "hw version: %#lx\n",
948 		 version & MCHP_I2SMCC_VERSION_MASK);
949 
950 	return 0;
951 }
952 
953 static int mchp_i2s_mcc_remove(struct platform_device *pdev)
954 {
955 	struct mchp_i2s_mcc_dev *dev = platform_get_drvdata(pdev);
956 
957 	clk_disable_unprepare(dev->pclk);
958 
959 	return 0;
960 }
961 
962 static struct platform_driver mchp_i2s_mcc_driver = {
963 	.driver		= {
964 		.name	= "mchp_i2s_mcc",
965 		.of_match_table	= of_match_ptr(mchp_i2s_mcc_dt_ids),
966 	},
967 	.probe		= mchp_i2s_mcc_probe,
968 	.remove		= mchp_i2s_mcc_remove,
969 };
970 module_platform_driver(mchp_i2s_mcc_driver);
971 
972 MODULE_DESCRIPTION("Microchip I2S Multi-Channel Controller driver");
973 MODULE_AUTHOR("Codrin Ciubotariu <codrin.ciubotariu@microchip.com>");
974 MODULE_LICENSE("GPL v2");
975