xref: /openbmc/linux/sound/soc/fsl/fsl_ssi.c (revision 62975d27)
1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // Freescale SSI ALSA SoC Digital Audio Interface (DAI) driver
4 //
5 // Author: Timur Tabi <timur@freescale.com>
6 //
7 // Copyright 2007-2010 Freescale Semiconductor, Inc.
8 //
9 // Some notes why imx-pcm-fiq is used instead of DMA on some boards:
10 //
11 // The i.MX SSI core has some nasty limitations in AC97 mode. While most
12 // sane processor vendors have a FIFO per AC97 slot, the i.MX has only
13 // one FIFO which combines all valid receive slots. We cannot even select
14 // which slots we want to receive. The WM9712 with which this driver
15 // was developed with always sends GPIO status data in slot 12 which
16 // we receive in our (PCM-) data stream. The only chance we have is to
17 // manually skip this data in the FIQ handler. With sampling rates different
18 // from 48000Hz not every frame has valid receive data, so the ratio
19 // between pcm data and GPIO status data changes. Our FIQ handler is not
20 // able to handle this, hence this driver only works with 48000Hz sampling
21 // rate.
22 // Reading and writing AC97 registers is another challenge. The core
23 // provides us status bits when the read register is updated with *another*
24 // value. When we read the same register two times (and the register still
25 // contains the same value) these status bits are not set. We work
26 // around this by not polling these bits but only wait a fixed delay.
27 
28 #include <linux/init.h>
29 #include <linux/io.h>
30 #include <linux/module.h>
31 #include <linux/interrupt.h>
32 #include <linux/clk.h>
33 #include <linux/ctype.h>
34 #include <linux/device.h>
35 #include <linux/delay.h>
36 #include <linux/mutex.h>
37 #include <linux/slab.h>
38 #include <linux/spinlock.h>
39 #include <linux/of.h>
40 #include <linux/of_address.h>
41 #include <linux/of_irq.h>
42 #include <linux/of_platform.h>
43 
44 #include <sound/core.h>
45 #include <sound/pcm.h>
46 #include <sound/pcm_params.h>
47 #include <sound/initval.h>
48 #include <sound/soc.h>
49 #include <sound/dmaengine_pcm.h>
50 
51 #include "fsl_ssi.h"
52 #include "imx-pcm.h"
53 
54 /* Define RX and TX to index ssi->regvals array; Can be 0 or 1 only */
55 #define RX 0
56 #define TX 1
57 
58 /**
59  * FSLSSI_I2S_FORMATS: audio formats supported by the SSI
60  *
61  * The SSI has a limitation in that the samples must be in the same byte
62  * order as the host CPU.  This is because when multiple bytes are written
63  * to the STX register, the bytes and bits must be written in the same
64  * order.  The STX is a shift register, so all the bits need to be aligned
65  * (bit-endianness must match byte-endianness).  Processors typically write
66  * the bits within a byte in the same order that the bytes of a word are
67  * written in.  So if the host CPU is big-endian, then only big-endian
68  * samples will be written to STX properly.
69  */
70 #ifdef __BIG_ENDIAN
71 #define FSLSSI_I2S_FORMATS \
72 	(SNDRV_PCM_FMTBIT_S8 | \
73 	 SNDRV_PCM_FMTBIT_S16_BE | \
74 	 SNDRV_PCM_FMTBIT_S18_3BE | \
75 	 SNDRV_PCM_FMTBIT_S20_3BE | \
76 	 SNDRV_PCM_FMTBIT_S24_3BE | \
77 	 SNDRV_PCM_FMTBIT_S24_BE)
78 #else
79 #define FSLSSI_I2S_FORMATS \
80 	(SNDRV_PCM_FMTBIT_S8 | \
81 	 SNDRV_PCM_FMTBIT_S16_LE | \
82 	 SNDRV_PCM_FMTBIT_S18_3LE | \
83 	 SNDRV_PCM_FMTBIT_S20_3LE | \
84 	 SNDRV_PCM_FMTBIT_S24_3LE | \
85 	 SNDRV_PCM_FMTBIT_S24_LE)
86 #endif
87 
88 /*
89  * In AC97 mode, TXDIR bit is forced to 0 and TFDIR bit is forced to 1:
90  *  - SSI inputs external bit clock and outputs frame sync clock -- CBM_CFS
91  *  - Also have NB_NF to mark these two clocks will not be inverted
92  */
93 #define FSLSSI_AC97_DAIFMT \
94 	(SND_SOC_DAIFMT_AC97 | \
95 	 SND_SOC_DAIFMT_CBM_CFS | \
96 	 SND_SOC_DAIFMT_NB_NF)
97 
98 #define FSLSSI_SIER_DBG_RX_FLAGS \
99 	(SSI_SIER_RFF0_EN | \
100 	 SSI_SIER_RLS_EN | \
101 	 SSI_SIER_RFS_EN | \
102 	 SSI_SIER_ROE0_EN | \
103 	 SSI_SIER_RFRC_EN)
104 #define FSLSSI_SIER_DBG_TX_FLAGS \
105 	(SSI_SIER_TFE0_EN | \
106 	 SSI_SIER_TLS_EN | \
107 	 SSI_SIER_TFS_EN | \
108 	 SSI_SIER_TUE0_EN | \
109 	 SSI_SIER_TFRC_EN)
110 
111 enum fsl_ssi_type {
112 	FSL_SSI_MCP8610,
113 	FSL_SSI_MX21,
114 	FSL_SSI_MX35,
115 	FSL_SSI_MX51,
116 };
117 
118 struct fsl_ssi_regvals {
119 	u32 sier;
120 	u32 srcr;
121 	u32 stcr;
122 	u32 scr;
123 };
124 
125 static bool fsl_ssi_readable_reg(struct device *dev, unsigned int reg)
126 {
127 	switch (reg) {
128 	case REG_SSI_SACCEN:
129 	case REG_SSI_SACCDIS:
130 		return false;
131 	default:
132 		return true;
133 	}
134 }
135 
136 static bool fsl_ssi_volatile_reg(struct device *dev, unsigned int reg)
137 {
138 	switch (reg) {
139 	case REG_SSI_STX0:
140 	case REG_SSI_STX1:
141 	case REG_SSI_SRX0:
142 	case REG_SSI_SRX1:
143 	case REG_SSI_SISR:
144 	case REG_SSI_SFCSR:
145 	case REG_SSI_SACNT:
146 	case REG_SSI_SACADD:
147 	case REG_SSI_SACDAT:
148 	case REG_SSI_SATAG:
149 	case REG_SSI_SACCST:
150 	case REG_SSI_SOR:
151 		return true;
152 	default:
153 		return false;
154 	}
155 }
156 
157 static bool fsl_ssi_precious_reg(struct device *dev, unsigned int reg)
158 {
159 	switch (reg) {
160 	case REG_SSI_SRX0:
161 	case REG_SSI_SRX1:
162 	case REG_SSI_SISR:
163 	case REG_SSI_SACADD:
164 	case REG_SSI_SACDAT:
165 	case REG_SSI_SATAG:
166 		return true;
167 	default:
168 		return false;
169 	}
170 }
171 
172 static bool fsl_ssi_writeable_reg(struct device *dev, unsigned int reg)
173 {
174 	switch (reg) {
175 	case REG_SSI_SRX0:
176 	case REG_SSI_SRX1:
177 	case REG_SSI_SACCST:
178 		return false;
179 	default:
180 		return true;
181 	}
182 }
183 
184 static const struct regmap_config fsl_ssi_regconfig = {
185 	.max_register = REG_SSI_SACCDIS,
186 	.reg_bits = 32,
187 	.val_bits = 32,
188 	.reg_stride = 4,
189 	.val_format_endian = REGMAP_ENDIAN_NATIVE,
190 	.num_reg_defaults_raw = REG_SSI_SACCDIS / sizeof(uint32_t) + 1,
191 	.readable_reg = fsl_ssi_readable_reg,
192 	.volatile_reg = fsl_ssi_volatile_reg,
193 	.precious_reg = fsl_ssi_precious_reg,
194 	.writeable_reg = fsl_ssi_writeable_reg,
195 	.cache_type = REGCACHE_FLAT,
196 };
197 
198 struct fsl_ssi_soc_data {
199 	bool imx;
200 	bool imx21regs; /* imx21-class SSI - no SACC{ST,EN,DIS} regs */
201 	bool offline_config;
202 	u32 sisr_write_mask;
203 };
204 
205 /**
206  * fsl_ssi: per-SSI private data
207  *
208  * @regs: Pointer to the regmap registers
209  * @irq: IRQ of this SSI
210  * @cpu_dai_drv: CPU DAI driver for this device
211  *
212  * @dai_fmt: DAI configuration this device is currently used with
213  * @streams: Mask of current active streams: BIT(TX) and BIT(RX)
214  * @i2s_net: I2S and Network mode configurations of SCR register
215  *           (this is the initial settings based on the DAI format)
216  * @synchronous: Use synchronous mode - both of TX and RX use STCK and SFCK
217  * @use_dma: DMA is used or FIQ with stream filter
218  * @use_dual_fifo: DMA with support for dual FIFO mode
219  * @has_ipg_clk_name: If "ipg" is in the clock name list of device tree
220  * @fifo_depth: Depth of the SSI FIFOs
221  * @slot_width: Width of each DAI slot
222  * @slots: Number of slots
223  * @regvals: Specific RX/TX register settings
224  *
225  * @clk: Clock source to access register
226  * @baudclk: Clock source to generate bit and frame-sync clocks
227  * @baudclk_streams: Active streams that are using baudclk
228  *
229  * @regcache_sfcsr: Cache sfcsr register value during suspend and resume
230  * @regcache_sacnt: Cache sacnt register value during suspend and resume
231  *
232  * @dma_params_tx: DMA transmit parameters
233  * @dma_params_rx: DMA receive parameters
234  * @ssi_phys: physical address of the SSI registers
235  *
236  * @fiq_params: FIQ stream filtering parameters
237  *
238  * @card_pdev: Platform_device pointer to register a sound card for PowerPC or
239  *             to register a CODEC platform device for AC97
240  * @card_name: Platform_device name to register a sound card for PowerPC or
241  *             to register a CODEC platform device for AC97
242  * @card_idx: The index of SSI to register a sound card for PowerPC or
243  *            to register a CODEC platform device for AC97
244  *
245  * @dbg_stats: Debugging statistics
246  *
247  * @soc: SoC specific data
248  * @dev: Pointer to &pdev->dev
249  *
250  * @fifo_watermark: The FIFO watermark setting. Notifies DMA when there are
251  *                  @fifo_watermark or fewer words in TX fifo or
252  *                  @fifo_watermark or more empty words in RX fifo.
253  * @dma_maxburst: Max number of words to transfer in one go. So far,
254  *                this is always the same as fifo_watermark.
255  *
256  * @ac97_reg_lock: Mutex lock to serialize AC97 register access operations
257  */
258 struct fsl_ssi {
259 	struct regmap *regs;
260 	int irq;
261 	struct snd_soc_dai_driver cpu_dai_drv;
262 
263 	unsigned int dai_fmt;
264 	u8 streams;
265 	u8 i2s_net;
266 	bool synchronous;
267 	bool use_dma;
268 	bool use_dual_fifo;
269 	bool has_ipg_clk_name;
270 	unsigned int fifo_depth;
271 	unsigned int slot_width;
272 	unsigned int slots;
273 	struct fsl_ssi_regvals regvals[2];
274 
275 	struct clk *clk;
276 	struct clk *baudclk;
277 	unsigned int baudclk_streams;
278 
279 	u32 regcache_sfcsr;
280 	u32 regcache_sacnt;
281 
282 	struct snd_dmaengine_dai_dma_data dma_params_tx;
283 	struct snd_dmaengine_dai_dma_data dma_params_rx;
284 	dma_addr_t ssi_phys;
285 
286 	struct imx_pcm_fiq_params fiq_params;
287 
288 	struct platform_device *card_pdev;
289 	char card_name[32];
290 	u32 card_idx;
291 
292 	struct fsl_ssi_dbg dbg_stats;
293 
294 	const struct fsl_ssi_soc_data *soc;
295 	struct device *dev;
296 
297 	u32 fifo_watermark;
298 	u32 dma_maxburst;
299 
300 	struct mutex ac97_reg_lock;
301 };
302 
303 /*
304  * SoC specific data
305  *
306  * Notes:
307  * 1) SSI in earlier SoCS has critical bits in control registers that
308  *    cannot be changed after SSI starts running -- a software reset
309  *    (set SSIEN to 0) is required to change their values. So adding
310  *    an offline_config flag for these SoCs.
311  * 2) SDMA is available since imx35. However, imx35 does not support
312  *    DMA bits changing when SSI is running, so set offline_config.
313  * 3) imx51 and later versions support register configurations when
314  *    SSI is running (SSIEN); For these versions, DMA needs to be
315  *    configured before SSI sends DMA request to avoid an undefined
316  *    DMA request on the SDMA side.
317  */
318 
319 static struct fsl_ssi_soc_data fsl_ssi_mpc8610 = {
320 	.imx = false,
321 	.offline_config = true,
322 	.sisr_write_mask = SSI_SISR_RFRC | SSI_SISR_TFRC |
323 			   SSI_SISR_ROE0 | SSI_SISR_ROE1 |
324 			   SSI_SISR_TUE0 | SSI_SISR_TUE1,
325 };
326 
327 static struct fsl_ssi_soc_data fsl_ssi_imx21 = {
328 	.imx = true,
329 	.imx21regs = true,
330 	.offline_config = true,
331 	.sisr_write_mask = 0,
332 };
333 
334 static struct fsl_ssi_soc_data fsl_ssi_imx35 = {
335 	.imx = true,
336 	.offline_config = true,
337 	.sisr_write_mask = SSI_SISR_RFRC | SSI_SISR_TFRC |
338 			   SSI_SISR_ROE0 | SSI_SISR_ROE1 |
339 			   SSI_SISR_TUE0 | SSI_SISR_TUE1,
340 };
341 
342 static struct fsl_ssi_soc_data fsl_ssi_imx51 = {
343 	.imx = true,
344 	.offline_config = false,
345 	.sisr_write_mask = SSI_SISR_ROE0 | SSI_SISR_ROE1 |
346 			   SSI_SISR_TUE0 | SSI_SISR_TUE1,
347 };
348 
349 static const struct of_device_id fsl_ssi_ids[] = {
350 	{ .compatible = "fsl,mpc8610-ssi", .data = &fsl_ssi_mpc8610 },
351 	{ .compatible = "fsl,imx51-ssi", .data = &fsl_ssi_imx51 },
352 	{ .compatible = "fsl,imx35-ssi", .data = &fsl_ssi_imx35 },
353 	{ .compatible = "fsl,imx21-ssi", .data = &fsl_ssi_imx21 },
354 	{}
355 };
356 MODULE_DEVICE_TABLE(of, fsl_ssi_ids);
357 
358 static bool fsl_ssi_is_ac97(struct fsl_ssi *ssi)
359 {
360 	return (ssi->dai_fmt & SND_SOC_DAIFMT_FORMAT_MASK) ==
361 		SND_SOC_DAIFMT_AC97;
362 }
363 
364 static bool fsl_ssi_is_i2s_master(struct fsl_ssi *ssi)
365 {
366 	return (ssi->dai_fmt & SND_SOC_DAIFMT_MASTER_MASK) ==
367 		SND_SOC_DAIFMT_CBS_CFS;
368 }
369 
370 static bool fsl_ssi_is_i2s_cbm_cfs(struct fsl_ssi *ssi)
371 {
372 	return (ssi->dai_fmt & SND_SOC_DAIFMT_MASTER_MASK) ==
373 		SND_SOC_DAIFMT_CBM_CFS;
374 }
375 
376 /**
377  * Interrupt handler to gather states
378  */
379 static irqreturn_t fsl_ssi_isr(int irq, void *dev_id)
380 {
381 	struct fsl_ssi *ssi = dev_id;
382 	struct regmap *regs = ssi->regs;
383 	u32 sisr, sisr2;
384 
385 	regmap_read(regs, REG_SSI_SISR, &sisr);
386 
387 	sisr2 = sisr & ssi->soc->sisr_write_mask;
388 	/* Clear the bits that we set */
389 	if (sisr2)
390 		regmap_write(regs, REG_SSI_SISR, sisr2);
391 
392 	fsl_ssi_dbg_isr(&ssi->dbg_stats, sisr);
393 
394 	return IRQ_HANDLED;
395 }
396 
397 /**
398  * Set SCR, SIER, STCR and SRCR registers with cached values in regvals
399  *
400  * Notes:
401  * 1) For offline_config SoCs, enable all necessary bits of both streams
402  *    when 1st stream starts, even if the opposite stream will not start
403  * 2) It also clears FIFO before setting regvals; SOR is safe to set online
404  */
405 static void fsl_ssi_config_enable(struct fsl_ssi *ssi, bool tx)
406 {
407 	struct fsl_ssi_regvals *vals = ssi->regvals;
408 	int dir = tx ? TX : RX;
409 	u32 sier, srcr, stcr;
410 
411 	/* Clear dirty data in the FIFO; It also prevents channel slipping */
412 	regmap_update_bits(ssi->regs, REG_SSI_SOR,
413 			   SSI_SOR_xX_CLR(tx), SSI_SOR_xX_CLR(tx));
414 
415 	/*
416 	 * On offline_config SoCs, SxCR and SIER are already configured when
417 	 * the previous stream started. So skip all SxCR and SIER settings
418 	 * to prevent online reconfigurations, then jump to set SCR directly
419 	 */
420 	if (ssi->soc->offline_config && ssi->streams)
421 		goto enable_scr;
422 
423 	if (ssi->soc->offline_config) {
424 		/*
425 		 * Online reconfiguration not supported, so enable all bits for
426 		 * both streams at once to avoid necessity of reconfigurations
427 		 */
428 		srcr = vals[RX].srcr | vals[TX].srcr;
429 		stcr = vals[RX].stcr | vals[TX].stcr;
430 		sier = vals[RX].sier | vals[TX].sier;
431 	} else {
432 		/* Otherwise, only set bits for the current stream */
433 		srcr = vals[dir].srcr;
434 		stcr = vals[dir].stcr;
435 		sier = vals[dir].sier;
436 	}
437 
438 	/* Configure SRCR, STCR and SIER at once */
439 	regmap_update_bits(ssi->regs, REG_SSI_SRCR, srcr, srcr);
440 	regmap_update_bits(ssi->regs, REG_SSI_STCR, stcr, stcr);
441 	regmap_update_bits(ssi->regs, REG_SSI_SIER, sier, sier);
442 
443 enable_scr:
444 	/*
445 	 * Start DMA before setting TE to avoid FIFO underrun
446 	 * which may cause a channel slip or a channel swap
447 	 *
448 	 * TODO: FIQ cases might also need this upon testing
449 	 */
450 	if (ssi->use_dma && tx) {
451 		int try = 100;
452 		u32 sfcsr;
453 
454 		/* Enable SSI first to send TX DMA request */
455 		regmap_update_bits(ssi->regs, REG_SSI_SCR,
456 				   SSI_SCR_SSIEN, SSI_SCR_SSIEN);
457 
458 		/* Busy wait until TX FIFO not empty -- DMA working */
459 		do {
460 			regmap_read(ssi->regs, REG_SSI_SFCSR, &sfcsr);
461 			if (SSI_SFCSR_TFCNT0(sfcsr))
462 				break;
463 		} while (--try);
464 
465 		/* FIFO still empty -- something might be wrong */
466 		if (!SSI_SFCSR_TFCNT0(sfcsr))
467 			dev_warn(ssi->dev, "Timeout waiting TX FIFO filling\n");
468 	}
469 	/* Enable all remaining bits in SCR */
470 	regmap_update_bits(ssi->regs, REG_SSI_SCR,
471 			   vals[dir].scr, vals[dir].scr);
472 
473 	/* Log the enabled stream to the mask */
474 	ssi->streams |= BIT(dir);
475 }
476 
477 /**
478  * Exclude bits that are used by the opposite stream
479  *
480  * When both streams are active, disabling some bits for the current stream
481  * might break the other stream if these bits are used by it.
482  *
483  * @vals : regvals of the current stream
484  * @avals: regvals of the opposite stream
485  * @aactive: active state of the opposite stream
486  *
487  *  1) XOR vals and avals to get the differences if the other stream is active;
488  *     Otherwise, return current vals if the other stream is not active
489  *  2) AND the result of 1) with the current vals
490  */
491 #define _ssi_xor_shared_bits(vals, avals, aactive) \
492 	((vals) ^ ((avals) * (aactive)))
493 
494 #define ssi_excl_shared_bits(vals, avals, aactive) \
495 	((vals) & _ssi_xor_shared_bits(vals, avals, aactive))
496 
497 /**
498  * Unset SCR, SIER, STCR and SRCR registers with cached values in regvals
499  *
500  * Notes:
501  * 1) For offline_config SoCs, to avoid online reconfigurations, disable all
502  *    bits of both streams at once when the last stream is abort to end
503  * 2) It also clears FIFO after unsetting regvals; SOR is safe to set online
504  */
505 static void fsl_ssi_config_disable(struct fsl_ssi *ssi, bool tx)
506 {
507 	struct fsl_ssi_regvals *vals, *avals;
508 	u32 sier, srcr, stcr, scr;
509 	int adir = tx ? RX : TX;
510 	int dir = tx ? TX : RX;
511 	bool aactive;
512 
513 	/* Check if the opposite stream is active */
514 	aactive = ssi->streams & BIT(adir);
515 
516 	vals = &ssi->regvals[dir];
517 
518 	/* Get regvals of the opposite stream to keep opposite stream safe */
519 	avals = &ssi->regvals[adir];
520 
521 	/*
522 	 * To keep the other stream safe, exclude shared bits between
523 	 * both streams, and get safe bits to disable current stream
524 	 */
525 	scr = ssi_excl_shared_bits(vals->scr, avals->scr, aactive);
526 
527 	/* Disable safe bits of SCR register for the current stream */
528 	regmap_update_bits(ssi->regs, REG_SSI_SCR, scr, 0);
529 
530 	/* Log the disabled stream to the mask */
531 	ssi->streams &= ~BIT(dir);
532 
533 	/*
534 	 * On offline_config SoCs, if the other stream is active, skip
535 	 * SxCR and SIER settings to prevent online reconfigurations
536 	 */
537 	if (ssi->soc->offline_config && aactive)
538 		goto fifo_clear;
539 
540 	if (ssi->soc->offline_config) {
541 		/* Now there is only current stream active, disable all bits */
542 		srcr = vals->srcr | avals->srcr;
543 		stcr = vals->stcr | avals->stcr;
544 		sier = vals->sier | avals->sier;
545 	} else {
546 		/*
547 		 * To keep the other stream safe, exclude shared bits between
548 		 * both streams, and get safe bits to disable current stream
549 		 */
550 		sier = ssi_excl_shared_bits(vals->sier, avals->sier, aactive);
551 		srcr = ssi_excl_shared_bits(vals->srcr, avals->srcr, aactive);
552 		stcr = ssi_excl_shared_bits(vals->stcr, avals->stcr, aactive);
553 	}
554 
555 	/* Clear configurations of SRCR, STCR and SIER at once */
556 	regmap_update_bits(ssi->regs, REG_SSI_SRCR, srcr, 0);
557 	regmap_update_bits(ssi->regs, REG_SSI_STCR, stcr, 0);
558 	regmap_update_bits(ssi->regs, REG_SSI_SIER, sier, 0);
559 
560 fifo_clear:
561 	/* Clear remaining data in the FIFO */
562 	regmap_update_bits(ssi->regs, REG_SSI_SOR,
563 			   SSI_SOR_xX_CLR(tx), SSI_SOR_xX_CLR(tx));
564 }
565 
566 static void fsl_ssi_tx_ac97_saccst_setup(struct fsl_ssi *ssi)
567 {
568 	struct regmap *regs = ssi->regs;
569 
570 	/* no SACC{ST,EN,DIS} regs on imx21-class SSI */
571 	if (!ssi->soc->imx21regs) {
572 		/* Disable all channel slots */
573 		regmap_write(regs, REG_SSI_SACCDIS, 0xff);
574 		/* Enable slots 3 & 4 -- PCM Playback Left & Right channels */
575 		regmap_write(regs, REG_SSI_SACCEN, 0x300);
576 	}
577 }
578 
579 /**
580  * Cache critical bits of SIER, SRCR, STCR and SCR to later set them safely
581  */
582 static void fsl_ssi_setup_regvals(struct fsl_ssi *ssi)
583 {
584 	struct fsl_ssi_regvals *vals = ssi->regvals;
585 
586 	vals[RX].sier = SSI_SIER_RFF0_EN | FSLSSI_SIER_DBG_RX_FLAGS;
587 	vals[RX].srcr = SSI_SRCR_RFEN0;
588 	vals[RX].scr = SSI_SCR_SSIEN | SSI_SCR_RE;
589 	vals[TX].sier = SSI_SIER_TFE0_EN | FSLSSI_SIER_DBG_TX_FLAGS;
590 	vals[TX].stcr = SSI_STCR_TFEN0;
591 	vals[TX].scr = SSI_SCR_SSIEN | SSI_SCR_TE;
592 
593 	/* AC97 has already enabled SSIEN, RE and TE, so ignore them */
594 	if (fsl_ssi_is_ac97(ssi))
595 		vals[RX].scr = vals[TX].scr = 0;
596 
597 	if (ssi->use_dual_fifo) {
598 		vals[RX].srcr |= SSI_SRCR_RFEN1;
599 		vals[TX].stcr |= SSI_STCR_TFEN1;
600 	}
601 
602 	if (ssi->use_dma) {
603 		vals[RX].sier |= SSI_SIER_RDMAE;
604 		vals[TX].sier |= SSI_SIER_TDMAE;
605 	} else {
606 		vals[RX].sier |= SSI_SIER_RIE;
607 		vals[TX].sier |= SSI_SIER_TIE;
608 	}
609 }
610 
611 static void fsl_ssi_setup_ac97(struct fsl_ssi *ssi)
612 {
613 	struct regmap *regs = ssi->regs;
614 
615 	/* Setup the clock control register */
616 	regmap_write(regs, REG_SSI_STCCR, SSI_SxCCR_WL(17) | SSI_SxCCR_DC(13));
617 	regmap_write(regs, REG_SSI_SRCCR, SSI_SxCCR_WL(17) | SSI_SxCCR_DC(13));
618 
619 	/* Enable AC97 mode and startup the SSI */
620 	regmap_write(regs, REG_SSI_SACNT, SSI_SACNT_AC97EN | SSI_SACNT_FV);
621 
622 	/* AC97 has to communicate with codec before starting a stream */
623 	regmap_update_bits(regs, REG_SSI_SCR,
624 			   SSI_SCR_SSIEN | SSI_SCR_TE | SSI_SCR_RE,
625 			   SSI_SCR_SSIEN | SSI_SCR_TE | SSI_SCR_RE);
626 
627 	regmap_write(regs, REG_SSI_SOR, SSI_SOR_WAIT(3));
628 }
629 
630 static int fsl_ssi_startup(struct snd_pcm_substream *substream,
631 			   struct snd_soc_dai *dai)
632 {
633 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
634 	struct fsl_ssi *ssi = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
635 	int ret;
636 
637 	ret = clk_prepare_enable(ssi->clk);
638 	if (ret)
639 		return ret;
640 
641 	/*
642 	 * When using dual fifo mode, it is safer to ensure an even period
643 	 * size. If appearing to an odd number while DMA always starts its
644 	 * task from fifo0, fifo1 would be neglected at the end of each
645 	 * period. But SSI would still access fifo1 with an invalid data.
646 	 */
647 	if (ssi->use_dual_fifo)
648 		snd_pcm_hw_constraint_step(substream->runtime, 0,
649 					   SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 2);
650 
651 	return 0;
652 }
653 
654 static void fsl_ssi_shutdown(struct snd_pcm_substream *substream,
655 			     struct snd_soc_dai *dai)
656 {
657 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
658 	struct fsl_ssi *ssi = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
659 
660 	clk_disable_unprepare(ssi->clk);
661 }
662 
663 /**
664  * Configure Digital Audio Interface bit clock
665  *
666  * Note: This function can be only called when using SSI as DAI master
667  *
668  * Quick instruction for parameters:
669  * freq: Output BCLK frequency = samplerate * slots * slot_width
670  *       (In 2-channel I2S Master mode, slot_width is fixed 32)
671  */
672 static int fsl_ssi_set_bclk(struct snd_pcm_substream *substream,
673 			    struct snd_soc_dai *dai,
674 			    struct snd_pcm_hw_params *hw_params)
675 {
676 	bool tx2, tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
677 	struct fsl_ssi *ssi = snd_soc_dai_get_drvdata(dai);
678 	struct regmap *regs = ssi->regs;
679 	u32 pm = 999, div2, psr, stccr, mask, afreq, factor, i;
680 	unsigned long clkrate, baudrate, tmprate;
681 	unsigned int channels = params_channels(hw_params);
682 	unsigned int slot_width = params_width(hw_params);
683 	unsigned int slots = 2;
684 	u64 sub, savesub = 100000;
685 	unsigned int freq;
686 	bool baudclk_is_used;
687 	int ret;
688 
689 	/* Override slots and slot_width if being specifically set... */
690 	if (ssi->slots)
691 		slots = ssi->slots;
692 	if (ssi->slot_width)
693 		slot_width = ssi->slot_width;
694 
695 	/* ...but force 32 bits for stereo audio using I2S Master Mode */
696 	if (channels == 2 &&
697 	    (ssi->i2s_net & SSI_SCR_I2S_MODE_MASK) == SSI_SCR_I2S_MODE_MASTER)
698 		slot_width = 32;
699 
700 	/* Generate bit clock based on the slot number and slot width */
701 	freq = slots * slot_width * params_rate(hw_params);
702 
703 	/* Don't apply it to any non-baudclk circumstance */
704 	if (IS_ERR(ssi->baudclk))
705 		return -EINVAL;
706 
707 	/*
708 	 * Hardware limitation: The bclk rate must be
709 	 * never greater than 1/5 IPG clock rate
710 	 */
711 	if (freq * 5 > clk_get_rate(ssi->clk)) {
712 		dev_err(dai->dev, "bitclk > ipgclk / 5\n");
713 		return -EINVAL;
714 	}
715 
716 	baudclk_is_used = ssi->baudclk_streams & ~(BIT(substream->stream));
717 
718 	/* It should be already enough to divide clock by setting pm alone */
719 	psr = 0;
720 	div2 = 0;
721 
722 	factor = (div2 + 1) * (7 * psr + 1) * 2;
723 
724 	for (i = 0; i < 255; i++) {
725 		tmprate = freq * factor * (i + 1);
726 
727 		if (baudclk_is_used)
728 			clkrate = clk_get_rate(ssi->baudclk);
729 		else
730 			clkrate = clk_round_rate(ssi->baudclk, tmprate);
731 
732 		clkrate /= factor;
733 		afreq = clkrate / (i + 1);
734 
735 		if (freq == afreq)
736 			sub = 0;
737 		else if (freq / afreq == 1)
738 			sub = freq - afreq;
739 		else if (afreq / freq == 1)
740 			sub = afreq - freq;
741 		else
742 			continue;
743 
744 		/* Calculate the fraction */
745 		sub *= 100000;
746 		do_div(sub, freq);
747 
748 		if (sub < savesub && !(i == 0 && psr == 0 && div2 == 0)) {
749 			baudrate = tmprate;
750 			savesub = sub;
751 			pm = i;
752 		}
753 
754 		/* We are lucky */
755 		if (savesub == 0)
756 			break;
757 	}
758 
759 	/* No proper pm found if it is still remaining the initial value */
760 	if (pm == 999) {
761 		dev_err(dai->dev, "failed to handle the required sysclk\n");
762 		return -EINVAL;
763 	}
764 
765 	stccr = SSI_SxCCR_PM(pm + 1) | (div2 ? SSI_SxCCR_DIV2 : 0) |
766 		(psr ? SSI_SxCCR_PSR : 0);
767 	mask = SSI_SxCCR_PM_MASK | SSI_SxCCR_DIV2 | SSI_SxCCR_PSR;
768 
769 	/* STCCR is used for RX in synchronous mode */
770 	tx2 = tx || ssi->synchronous;
771 	regmap_update_bits(regs, REG_SSI_SxCCR(tx2), mask, stccr);
772 
773 	if (!baudclk_is_used) {
774 		ret = clk_set_rate(ssi->baudclk, baudrate);
775 		if (ret) {
776 			dev_err(dai->dev, "failed to set baudclk rate\n");
777 			return -EINVAL;
778 		}
779 	}
780 
781 	return 0;
782 }
783 
784 /**
785  * Configure SSI based on PCM hardware parameters
786  *
787  * Notes:
788  * 1) SxCCR.WL bits are critical bits that require SSI to be temporarily
789  *    disabled on offline_config SoCs. Even for online configurable SoCs
790  *    running in synchronous mode (both TX and RX use STCCR), it is not
791  *    safe to re-configure them when both two streams start running.
792  * 2) SxCCR.PM, SxCCR.DIV2 and SxCCR.PSR bits will be configured in the
793  *    fsl_ssi_set_bclk() if SSI is the DAI clock master.
794  */
795 static int fsl_ssi_hw_params(struct snd_pcm_substream *substream,
796 			     struct snd_pcm_hw_params *hw_params,
797 			     struct snd_soc_dai *dai)
798 {
799 	bool tx2, tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
800 	struct fsl_ssi *ssi = snd_soc_dai_get_drvdata(dai);
801 	struct regmap *regs = ssi->regs;
802 	unsigned int channels = params_channels(hw_params);
803 	unsigned int sample_size = params_width(hw_params);
804 	u32 wl = SSI_SxCCR_WL(sample_size);
805 	int ret;
806 
807 	if (fsl_ssi_is_i2s_master(ssi)) {
808 		ret = fsl_ssi_set_bclk(substream, dai, hw_params);
809 		if (ret)
810 			return ret;
811 
812 		/* Do not enable the clock if it is already enabled */
813 		if (!(ssi->baudclk_streams & BIT(substream->stream))) {
814 			ret = clk_prepare_enable(ssi->baudclk);
815 			if (ret)
816 				return ret;
817 
818 			ssi->baudclk_streams |= BIT(substream->stream);
819 		}
820 	}
821 
822 	/*
823 	 * SSI is properly configured if it is enabled and running in
824 	 * the synchronous mode; Note that AC97 mode is an exception
825 	 * that should set separate configurations for STCCR and SRCCR
826 	 * despite running in the synchronous mode.
827 	 */
828 	if (ssi->streams && ssi->synchronous)
829 		return 0;
830 
831 	if (!fsl_ssi_is_ac97(ssi)) {
832 		/*
833 		 * Keep the ssi->i2s_net intact while having a local variable
834 		 * to override settings for special use cases. Otherwise, the
835 		 * ssi->i2s_net will lose the settings for regular use cases.
836 		 */
837 		u8 i2s_net = ssi->i2s_net;
838 
839 		/* Normal + Network mode to send 16-bit data in 32-bit frames */
840 		if (fsl_ssi_is_i2s_cbm_cfs(ssi) && sample_size == 16)
841 			i2s_net = SSI_SCR_I2S_MODE_NORMAL | SSI_SCR_NET;
842 
843 		/* Use Normal mode to send mono data at 1st slot of 2 slots */
844 		if (channels == 1)
845 			i2s_net = SSI_SCR_I2S_MODE_NORMAL;
846 
847 		regmap_update_bits(regs, REG_SSI_SCR,
848 				   SSI_SCR_I2S_NET_MASK, i2s_net);
849 	}
850 
851 	/* In synchronous mode, the SSI uses STCCR for capture */
852 	tx2 = tx || ssi->synchronous;
853 	regmap_update_bits(regs, REG_SSI_SxCCR(tx2), SSI_SxCCR_WL_MASK, wl);
854 
855 	return 0;
856 }
857 
858 static int fsl_ssi_hw_free(struct snd_pcm_substream *substream,
859 			   struct snd_soc_dai *dai)
860 {
861 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
862 	struct fsl_ssi *ssi = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
863 
864 	if (fsl_ssi_is_i2s_master(ssi) &&
865 	    ssi->baudclk_streams & BIT(substream->stream)) {
866 		clk_disable_unprepare(ssi->baudclk);
867 		ssi->baudclk_streams &= ~BIT(substream->stream);
868 	}
869 
870 	return 0;
871 }
872 
873 static int _fsl_ssi_set_dai_fmt(struct fsl_ssi *ssi, unsigned int fmt)
874 {
875 	u32 strcr = 0, scr = 0, stcr, srcr, mask;
876 
877 	ssi->dai_fmt = fmt;
878 
879 	/* Synchronize frame sync clock for TE to avoid data slipping */
880 	scr |= SSI_SCR_SYNC_TX_FS;
881 
882 	/* Set to default shifting settings: LSB_ALIGNED */
883 	strcr |= SSI_STCR_TXBIT0;
884 
885 	/* Use Network mode as default */
886 	ssi->i2s_net = SSI_SCR_NET;
887 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
888 	case SND_SOC_DAIFMT_I2S:
889 		switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
890 		case SND_SOC_DAIFMT_CBS_CFS:
891 			if (IS_ERR(ssi->baudclk)) {
892 				dev_err(ssi->dev,
893 					"missing baudclk for master mode\n");
894 				return -EINVAL;
895 			}
896 			/* fall through */
897 		case SND_SOC_DAIFMT_CBM_CFS:
898 			ssi->i2s_net |= SSI_SCR_I2S_MODE_MASTER;
899 			break;
900 		case SND_SOC_DAIFMT_CBM_CFM:
901 			ssi->i2s_net |= SSI_SCR_I2S_MODE_SLAVE;
902 			break;
903 		default:
904 			return -EINVAL;
905 		}
906 
907 		regmap_update_bits(ssi->regs, REG_SSI_STCCR,
908 				   SSI_SxCCR_DC_MASK, SSI_SxCCR_DC(2));
909 		regmap_update_bits(ssi->regs, REG_SSI_SRCCR,
910 				   SSI_SxCCR_DC_MASK, SSI_SxCCR_DC(2));
911 
912 		/* Data on rising edge of bclk, frame low, 1clk before data */
913 		strcr |= SSI_STCR_TFSI | SSI_STCR_TSCKP | SSI_STCR_TEFS;
914 		break;
915 	case SND_SOC_DAIFMT_LEFT_J:
916 		/* Data on rising edge of bclk, frame high */
917 		strcr |= SSI_STCR_TSCKP;
918 		break;
919 	case SND_SOC_DAIFMT_DSP_A:
920 		/* Data on rising edge of bclk, frame high, 1clk before data */
921 		strcr |= SSI_STCR_TFSL | SSI_STCR_TSCKP | SSI_STCR_TEFS;
922 		break;
923 	case SND_SOC_DAIFMT_DSP_B:
924 		/* Data on rising edge of bclk, frame high */
925 		strcr |= SSI_STCR_TFSL | SSI_STCR_TSCKP;
926 		break;
927 	case SND_SOC_DAIFMT_AC97:
928 		/* Data on falling edge of bclk, frame high, 1clk before data */
929 		strcr |= SSI_STCR_TEFS;
930 		break;
931 	default:
932 		return -EINVAL;
933 	}
934 
935 	scr |= ssi->i2s_net;
936 
937 	/* DAI clock inversion */
938 	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
939 	case SND_SOC_DAIFMT_NB_NF:
940 		/* Nothing to do for both normal cases */
941 		break;
942 	case SND_SOC_DAIFMT_IB_NF:
943 		/* Invert bit clock */
944 		strcr ^= SSI_STCR_TSCKP;
945 		break;
946 	case SND_SOC_DAIFMT_NB_IF:
947 		/* Invert frame clock */
948 		strcr ^= SSI_STCR_TFSI;
949 		break;
950 	case SND_SOC_DAIFMT_IB_IF:
951 		/* Invert both clocks */
952 		strcr ^= SSI_STCR_TSCKP;
953 		strcr ^= SSI_STCR_TFSI;
954 		break;
955 	default:
956 		return -EINVAL;
957 	}
958 
959 	/* DAI clock master masks */
960 	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
961 	case SND_SOC_DAIFMT_CBS_CFS:
962 		/* Output bit and frame sync clocks */
963 		strcr |= SSI_STCR_TFDIR | SSI_STCR_TXDIR;
964 		scr |= SSI_SCR_SYS_CLK_EN;
965 		break;
966 	case SND_SOC_DAIFMT_CBM_CFM:
967 		/* Input bit or frame sync clocks */
968 		break;
969 	case SND_SOC_DAIFMT_CBM_CFS:
970 		/* Input bit clock but output frame sync clock */
971 		strcr |= SSI_STCR_TFDIR;
972 		break;
973 	default:
974 		return -EINVAL;
975 	}
976 
977 	stcr = strcr;
978 	srcr = strcr;
979 
980 	/* Set SYN mode and clear RXDIR bit when using SYN or AC97 mode */
981 	if (ssi->synchronous || fsl_ssi_is_ac97(ssi)) {
982 		srcr &= ~SSI_SRCR_RXDIR;
983 		scr |= SSI_SCR_SYN;
984 	}
985 
986 	mask = SSI_STCR_TFDIR | SSI_STCR_TXDIR | SSI_STCR_TSCKP |
987 	       SSI_STCR_TFSL | SSI_STCR_TFSI | SSI_STCR_TEFS | SSI_STCR_TXBIT0;
988 
989 	regmap_update_bits(ssi->regs, REG_SSI_STCR, mask, stcr);
990 	regmap_update_bits(ssi->regs, REG_SSI_SRCR, mask, srcr);
991 
992 	mask = SSI_SCR_SYNC_TX_FS | SSI_SCR_I2S_MODE_MASK |
993 	       SSI_SCR_SYS_CLK_EN | SSI_SCR_SYN;
994 	regmap_update_bits(ssi->regs, REG_SSI_SCR, mask, scr);
995 
996 	return 0;
997 }
998 
999 /**
1000  * Configure Digital Audio Interface (DAI) Format
1001  */
1002 static int fsl_ssi_set_dai_fmt(struct snd_soc_dai *dai, unsigned int fmt)
1003 {
1004 	struct fsl_ssi *ssi = snd_soc_dai_get_drvdata(dai);
1005 
1006 	/* AC97 configured DAIFMT earlier in the probe() */
1007 	if (fsl_ssi_is_ac97(ssi))
1008 		return 0;
1009 
1010 	return _fsl_ssi_set_dai_fmt(ssi, fmt);
1011 }
1012 
1013 /**
1014  * Set TDM slot number and slot width
1015  */
1016 static int fsl_ssi_set_dai_tdm_slot(struct snd_soc_dai *dai, u32 tx_mask,
1017 				    u32 rx_mask, int slots, int slot_width)
1018 {
1019 	struct fsl_ssi *ssi = snd_soc_dai_get_drvdata(dai);
1020 	struct regmap *regs = ssi->regs;
1021 	u32 val;
1022 
1023 	/* The word length should be 8, 10, 12, 16, 18, 20, 22 or 24 */
1024 	if (slot_width & 1 || slot_width < 8 || slot_width > 24) {
1025 		dev_err(dai->dev, "invalid slot width: %d\n", slot_width);
1026 		return -EINVAL;
1027 	}
1028 
1029 	/* The slot number should be >= 2 if using Network mode or I2S mode */
1030 	if (ssi->i2s_net && slots < 2) {
1031 		dev_err(dai->dev, "slot number should be >= 2 in I2S or NET\n");
1032 		return -EINVAL;
1033 	}
1034 
1035 	regmap_update_bits(regs, REG_SSI_STCCR,
1036 			   SSI_SxCCR_DC_MASK, SSI_SxCCR_DC(slots));
1037 	regmap_update_bits(regs, REG_SSI_SRCCR,
1038 			   SSI_SxCCR_DC_MASK, SSI_SxCCR_DC(slots));
1039 
1040 	/* Save the SCR register value */
1041 	regmap_read(regs, REG_SSI_SCR, &val);
1042 	/* Temporarily enable SSI to allow SxMSKs to be configurable */
1043 	regmap_update_bits(regs, REG_SSI_SCR, SSI_SCR_SSIEN, SSI_SCR_SSIEN);
1044 
1045 	regmap_write(regs, REG_SSI_STMSK, ~tx_mask);
1046 	regmap_write(regs, REG_SSI_SRMSK, ~rx_mask);
1047 
1048 	/* Restore the value of SSIEN bit */
1049 	regmap_update_bits(regs, REG_SSI_SCR, SSI_SCR_SSIEN, val);
1050 
1051 	ssi->slot_width = slot_width;
1052 	ssi->slots = slots;
1053 
1054 	return 0;
1055 }
1056 
1057 /**
1058  * Start or stop SSI and corresponding DMA transaction.
1059  *
1060  * The DMA channel is in external master start and pause mode, which
1061  * means the SSI completely controls the flow of data.
1062  */
1063 static int fsl_ssi_trigger(struct snd_pcm_substream *substream, int cmd,
1064 			   struct snd_soc_dai *dai)
1065 {
1066 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
1067 	struct fsl_ssi *ssi = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
1068 	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
1069 
1070 	switch (cmd) {
1071 	case SNDRV_PCM_TRIGGER_START:
1072 	case SNDRV_PCM_TRIGGER_RESUME:
1073 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1074 		/*
1075 		 * SACCST might be modified via AC Link by a CODEC if it sends
1076 		 * extra bits in their SLOTREQ requests, which'll accidentally
1077 		 * send valid data to slots other than normal playback slots.
1078 		 *
1079 		 * To be safe, configure SACCST right before TX starts.
1080 		 */
1081 		if (tx && fsl_ssi_is_ac97(ssi))
1082 			fsl_ssi_tx_ac97_saccst_setup(ssi);
1083 		fsl_ssi_config_enable(ssi, tx);
1084 		break;
1085 
1086 	case SNDRV_PCM_TRIGGER_STOP:
1087 	case SNDRV_PCM_TRIGGER_SUSPEND:
1088 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1089 		fsl_ssi_config_disable(ssi, tx);
1090 		break;
1091 
1092 	default:
1093 		return -EINVAL;
1094 	}
1095 
1096 	return 0;
1097 }
1098 
1099 static int fsl_ssi_dai_probe(struct snd_soc_dai *dai)
1100 {
1101 	struct fsl_ssi *ssi = snd_soc_dai_get_drvdata(dai);
1102 
1103 	if (ssi->soc->imx && ssi->use_dma)
1104 		snd_soc_dai_init_dma_data(dai, &ssi->dma_params_tx,
1105 					  &ssi->dma_params_rx);
1106 
1107 	return 0;
1108 }
1109 
1110 static const struct snd_soc_dai_ops fsl_ssi_dai_ops = {
1111 	.startup = fsl_ssi_startup,
1112 	.shutdown = fsl_ssi_shutdown,
1113 	.hw_params = fsl_ssi_hw_params,
1114 	.hw_free = fsl_ssi_hw_free,
1115 	.set_fmt = fsl_ssi_set_dai_fmt,
1116 	.set_tdm_slot = fsl_ssi_set_dai_tdm_slot,
1117 	.trigger = fsl_ssi_trigger,
1118 };
1119 
1120 static struct snd_soc_dai_driver fsl_ssi_dai_template = {
1121 	.probe = fsl_ssi_dai_probe,
1122 	.playback = {
1123 		.stream_name = "CPU-Playback",
1124 		.channels_min = 1,
1125 		.channels_max = 32,
1126 		.rates = SNDRV_PCM_RATE_CONTINUOUS,
1127 		.formats = FSLSSI_I2S_FORMATS,
1128 	},
1129 	.capture = {
1130 		.stream_name = "CPU-Capture",
1131 		.channels_min = 1,
1132 		.channels_max = 32,
1133 		.rates = SNDRV_PCM_RATE_CONTINUOUS,
1134 		.formats = FSLSSI_I2S_FORMATS,
1135 	},
1136 	.ops = &fsl_ssi_dai_ops,
1137 };
1138 
1139 static const struct snd_soc_component_driver fsl_ssi_component = {
1140 	.name = "fsl-ssi",
1141 };
1142 
1143 static struct snd_soc_dai_driver fsl_ssi_ac97_dai = {
1144 	.symmetric_channels = 1,
1145 	.probe = fsl_ssi_dai_probe,
1146 	.playback = {
1147 		.stream_name = "AC97 Playback",
1148 		.channels_min = 2,
1149 		.channels_max = 2,
1150 		.rates = SNDRV_PCM_RATE_8000_48000,
1151 		.formats = SNDRV_PCM_FMTBIT_S16 | SNDRV_PCM_FMTBIT_S20,
1152 	},
1153 	.capture = {
1154 		.stream_name = "AC97 Capture",
1155 		.channels_min = 2,
1156 		.channels_max = 2,
1157 		.rates = SNDRV_PCM_RATE_48000,
1158 		/* 16-bit capture is broken (errata ERR003778) */
1159 		.formats = SNDRV_PCM_FMTBIT_S20,
1160 	},
1161 	.ops = &fsl_ssi_dai_ops,
1162 };
1163 
1164 static struct fsl_ssi *fsl_ac97_data;
1165 
1166 static void fsl_ssi_ac97_write(struct snd_ac97 *ac97, unsigned short reg,
1167 			       unsigned short val)
1168 {
1169 	struct regmap *regs = fsl_ac97_data->regs;
1170 	unsigned int lreg;
1171 	unsigned int lval;
1172 	int ret;
1173 
1174 	if (reg > 0x7f)
1175 		return;
1176 
1177 	mutex_lock(&fsl_ac97_data->ac97_reg_lock);
1178 
1179 	ret = clk_prepare_enable(fsl_ac97_data->clk);
1180 	if (ret) {
1181 		pr_err("ac97 write clk_prepare_enable failed: %d\n",
1182 			ret);
1183 		goto ret_unlock;
1184 	}
1185 
1186 	lreg = reg <<  12;
1187 	regmap_write(regs, REG_SSI_SACADD, lreg);
1188 
1189 	lval = val << 4;
1190 	regmap_write(regs, REG_SSI_SACDAT, lval);
1191 
1192 	regmap_update_bits(regs, REG_SSI_SACNT,
1193 			   SSI_SACNT_RDWR_MASK, SSI_SACNT_WR);
1194 	udelay(100);
1195 
1196 	clk_disable_unprepare(fsl_ac97_data->clk);
1197 
1198 ret_unlock:
1199 	mutex_unlock(&fsl_ac97_data->ac97_reg_lock);
1200 }
1201 
1202 static unsigned short fsl_ssi_ac97_read(struct snd_ac97 *ac97,
1203 					unsigned short reg)
1204 {
1205 	struct regmap *regs = fsl_ac97_data->regs;
1206 	unsigned short val = 0;
1207 	u32 reg_val;
1208 	unsigned int lreg;
1209 	int ret;
1210 
1211 	mutex_lock(&fsl_ac97_data->ac97_reg_lock);
1212 
1213 	ret = clk_prepare_enable(fsl_ac97_data->clk);
1214 	if (ret) {
1215 		pr_err("ac97 read clk_prepare_enable failed: %d\n", ret);
1216 		goto ret_unlock;
1217 	}
1218 
1219 	lreg = (reg & 0x7f) <<  12;
1220 	regmap_write(regs, REG_SSI_SACADD, lreg);
1221 	regmap_update_bits(regs, REG_SSI_SACNT,
1222 			   SSI_SACNT_RDWR_MASK, SSI_SACNT_RD);
1223 
1224 	udelay(100);
1225 
1226 	regmap_read(regs, REG_SSI_SACDAT, &reg_val);
1227 	val = (reg_val >> 4) & 0xffff;
1228 
1229 	clk_disable_unprepare(fsl_ac97_data->clk);
1230 
1231 ret_unlock:
1232 	mutex_unlock(&fsl_ac97_data->ac97_reg_lock);
1233 	return val;
1234 }
1235 
1236 static struct snd_ac97_bus_ops fsl_ssi_ac97_ops = {
1237 	.read = fsl_ssi_ac97_read,
1238 	.write = fsl_ssi_ac97_write,
1239 };
1240 
1241 /**
1242  * Initialize SSI registers
1243  */
1244 static int fsl_ssi_hw_init(struct fsl_ssi *ssi)
1245 {
1246 	u32 wm = ssi->fifo_watermark;
1247 
1248 	/* Initialize regvals */
1249 	fsl_ssi_setup_regvals(ssi);
1250 
1251 	/* Set watermarks */
1252 	regmap_write(ssi->regs, REG_SSI_SFCSR,
1253 		     SSI_SFCSR_TFWM0(wm) | SSI_SFCSR_RFWM0(wm) |
1254 		     SSI_SFCSR_TFWM1(wm) | SSI_SFCSR_RFWM1(wm));
1255 
1256 	/* Enable Dual FIFO mode */
1257 	if (ssi->use_dual_fifo)
1258 		regmap_update_bits(ssi->regs, REG_SSI_SCR,
1259 				   SSI_SCR_TCH_EN, SSI_SCR_TCH_EN);
1260 
1261 	/* AC97 should start earlier to communicate with CODECs */
1262 	if (fsl_ssi_is_ac97(ssi)) {
1263 		_fsl_ssi_set_dai_fmt(ssi, ssi->dai_fmt);
1264 		fsl_ssi_setup_ac97(ssi);
1265 	}
1266 
1267 	return 0;
1268 }
1269 
1270 /**
1271  * Clear SSI registers
1272  */
1273 static void fsl_ssi_hw_clean(struct fsl_ssi *ssi)
1274 {
1275 	/* Disable registers for AC97 */
1276 	if (fsl_ssi_is_ac97(ssi)) {
1277 		/* Disable TE and RE bits first */
1278 		regmap_update_bits(ssi->regs, REG_SSI_SCR,
1279 				   SSI_SCR_TE | SSI_SCR_RE, 0);
1280 		/* Disable AC97 mode */
1281 		regmap_write(ssi->regs, REG_SSI_SACNT, 0);
1282 		/* Unset WAIT bits */
1283 		regmap_write(ssi->regs, REG_SSI_SOR, 0);
1284 		/* Disable SSI -- software reset */
1285 		regmap_update_bits(ssi->regs, REG_SSI_SCR, SSI_SCR_SSIEN, 0);
1286 	}
1287 }
1288 /**
1289  * Make every character in a string lower-case
1290  */
1291 static void make_lowercase(char *s)
1292 {
1293 	if (!s)
1294 		return;
1295 	for (; *s; s++)
1296 		*s = tolower(*s);
1297 }
1298 
1299 static int fsl_ssi_imx_probe(struct platform_device *pdev,
1300 			     struct fsl_ssi *ssi, void __iomem *iomem)
1301 {
1302 	struct device *dev = &pdev->dev;
1303 	int ret;
1304 
1305 	/* Backward compatible for a DT without ipg clock name assigned */
1306 	if (ssi->has_ipg_clk_name)
1307 		ssi->clk = devm_clk_get(dev, "ipg");
1308 	else
1309 		ssi->clk = devm_clk_get(dev, NULL);
1310 	if (IS_ERR(ssi->clk)) {
1311 		ret = PTR_ERR(ssi->clk);
1312 		dev_err(dev, "failed to get clock: %d\n", ret);
1313 		return ret;
1314 	}
1315 
1316 	/* Enable the clock since regmap will not handle it in this case */
1317 	if (!ssi->has_ipg_clk_name) {
1318 		ret = clk_prepare_enable(ssi->clk);
1319 		if (ret) {
1320 			dev_err(dev, "clk_prepare_enable failed: %d\n", ret);
1321 			return ret;
1322 		}
1323 	}
1324 
1325 	/* Do not error out for slave cases that live without a baud clock */
1326 	ssi->baudclk = devm_clk_get(dev, "baud");
1327 	if (IS_ERR(ssi->baudclk))
1328 		dev_dbg(dev, "failed to get baud clock: %ld\n",
1329 			 PTR_ERR(ssi->baudclk));
1330 
1331 	ssi->dma_params_tx.maxburst = ssi->dma_maxburst;
1332 	ssi->dma_params_rx.maxburst = ssi->dma_maxburst;
1333 	ssi->dma_params_tx.addr = ssi->ssi_phys + REG_SSI_STX0;
1334 	ssi->dma_params_rx.addr = ssi->ssi_phys + REG_SSI_SRX0;
1335 
1336 	/* Use even numbers to avoid channel swap due to SDMA script design */
1337 	if (ssi->use_dual_fifo) {
1338 		ssi->dma_params_tx.maxburst &= ~0x1;
1339 		ssi->dma_params_rx.maxburst &= ~0x1;
1340 	}
1341 
1342 	if (!ssi->use_dma) {
1343 		/*
1344 		 * Some boards use an incompatible codec. Use imx-fiq-pcm-audio
1345 		 * to get it working, as DMA is not possible in this situation.
1346 		 */
1347 		ssi->fiq_params.irq = ssi->irq;
1348 		ssi->fiq_params.base = iomem;
1349 		ssi->fiq_params.dma_params_rx = &ssi->dma_params_rx;
1350 		ssi->fiq_params.dma_params_tx = &ssi->dma_params_tx;
1351 
1352 		ret = imx_pcm_fiq_init(pdev, &ssi->fiq_params);
1353 		if (ret)
1354 			goto error_pcm;
1355 	} else {
1356 		ret = imx_pcm_dma_init(pdev, IMX_SSI_DMABUF_SIZE);
1357 		if (ret)
1358 			goto error_pcm;
1359 	}
1360 
1361 	return 0;
1362 
1363 error_pcm:
1364 	if (!ssi->has_ipg_clk_name)
1365 		clk_disable_unprepare(ssi->clk);
1366 
1367 	return ret;
1368 }
1369 
1370 static void fsl_ssi_imx_clean(struct platform_device *pdev, struct fsl_ssi *ssi)
1371 {
1372 	if (!ssi->use_dma)
1373 		imx_pcm_fiq_exit(pdev);
1374 	if (!ssi->has_ipg_clk_name)
1375 		clk_disable_unprepare(ssi->clk);
1376 }
1377 
1378 static int fsl_ssi_probe_from_dt(struct fsl_ssi *ssi)
1379 {
1380 	struct device *dev = ssi->dev;
1381 	struct device_node *np = dev->of_node;
1382 	const struct of_device_id *of_id;
1383 	const char *p, *sprop;
1384 	const __be32 *iprop;
1385 	u32 dmas[4];
1386 	int ret;
1387 
1388 	of_id = of_match_device(fsl_ssi_ids, dev);
1389 	if (!of_id || !of_id->data)
1390 		return -EINVAL;
1391 
1392 	ssi->soc = of_id->data;
1393 
1394 	ret = of_property_match_string(np, "clock-names", "ipg");
1395 	/* Get error code if not found */
1396 	ssi->has_ipg_clk_name = ret >= 0;
1397 
1398 	/* Check if being used in AC97 mode */
1399 	sprop = of_get_property(np, "fsl,mode", NULL);
1400 	if (sprop && !strcmp(sprop, "ac97-slave")) {
1401 		ssi->dai_fmt = FSLSSI_AC97_DAIFMT;
1402 
1403 		ret = of_property_read_u32(np, "cell-index", &ssi->card_idx);
1404 		if (ret) {
1405 			dev_err(dev, "failed to get SSI index property\n");
1406 			return -EINVAL;
1407 		}
1408 		strcpy(ssi->card_name, "ac97-codec");
1409 	} else if (!of_find_property(np, "fsl,ssi-asynchronous", NULL)) {
1410 		/*
1411 		 * In synchronous mode, STCK and STFS ports are used by RX
1412 		 * as well. So the software should limit the sample rates,
1413 		 * sample bits and channels to be symmetric.
1414 		 *
1415 		 * This is exclusive with FSLSSI_AC97_FORMATS as AC97 runs
1416 		 * in the SSI synchronous mode however it does not have to
1417 		 * limit symmetric sample rates and sample bits.
1418 		 */
1419 		ssi->synchronous = true;
1420 	}
1421 
1422 	/* Select DMA or FIQ */
1423 	ssi->use_dma = !of_property_read_bool(np, "fsl,fiq-stream-filter");
1424 
1425 	/* Fetch FIFO depth; Set to 8 for older DT without this property */
1426 	iprop = of_get_property(np, "fsl,fifo-depth", NULL);
1427 	if (iprop)
1428 		ssi->fifo_depth = be32_to_cpup(iprop);
1429 	else
1430 		ssi->fifo_depth = 8;
1431 
1432 	/* Use dual FIFO mode depending on the support from SDMA script */
1433 	ret = of_property_read_u32_array(np, "dmas", dmas, 4);
1434 	if (ssi->use_dma && !ret && dmas[2] == IMX_DMATYPE_SSI_DUAL)
1435 		ssi->use_dual_fifo = true;
1436 
1437 	/*
1438 	 * Backward compatible for older bindings by manually triggering the
1439 	 * machine driver's probe(). Use /compatible property, including the
1440 	 * address of CPU DAI driver structure, as the name of machine driver
1441 	 *
1442 	 * If card_name is set by AC97 earlier, bypass here since it uses a
1443 	 * different name to register the device.
1444 	 */
1445 	if (!ssi->card_name[0] && of_get_property(np, "codec-handle", NULL)) {
1446 		struct device_node *root = of_find_node_by_path("/");
1447 
1448 		sprop = of_get_property(root, "compatible", NULL);
1449 		of_node_put(root);
1450 		/* Strip "fsl," in the compatible name if applicable */
1451 		p = strrchr(sprop, ',');
1452 		if (p)
1453 			sprop = p + 1;
1454 		snprintf(ssi->card_name, sizeof(ssi->card_name),
1455 			 "snd-soc-%s", sprop);
1456 		make_lowercase(ssi->card_name);
1457 		ssi->card_idx = 0;
1458 	}
1459 
1460 	return 0;
1461 }
1462 
1463 static int fsl_ssi_probe(struct platform_device *pdev)
1464 {
1465 	struct regmap_config regconfig = fsl_ssi_regconfig;
1466 	struct device *dev = &pdev->dev;
1467 	struct fsl_ssi *ssi;
1468 	struct resource *res;
1469 	void __iomem *iomem;
1470 	int ret = 0;
1471 
1472 	ssi = devm_kzalloc(dev, sizeof(*ssi), GFP_KERNEL);
1473 	if (!ssi)
1474 		return -ENOMEM;
1475 
1476 	ssi->dev = dev;
1477 
1478 	/* Probe from DT */
1479 	ret = fsl_ssi_probe_from_dt(ssi);
1480 	if (ret)
1481 		return ret;
1482 
1483 	if (fsl_ssi_is_ac97(ssi)) {
1484 		memcpy(&ssi->cpu_dai_drv, &fsl_ssi_ac97_dai,
1485 		       sizeof(fsl_ssi_ac97_dai));
1486 		fsl_ac97_data = ssi;
1487 	} else {
1488 		memcpy(&ssi->cpu_dai_drv, &fsl_ssi_dai_template,
1489 		       sizeof(fsl_ssi_dai_template));
1490 	}
1491 	ssi->cpu_dai_drv.name = dev_name(dev);
1492 
1493 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1494 	iomem = devm_ioremap_resource(dev, res);
1495 	if (IS_ERR(iomem))
1496 		return PTR_ERR(iomem);
1497 	ssi->ssi_phys = res->start;
1498 
1499 	if (ssi->soc->imx21regs) {
1500 		/* No SACC{ST,EN,DIS} regs in imx21-class SSI */
1501 		regconfig.max_register = REG_SSI_SRMSK;
1502 		regconfig.num_reg_defaults_raw =
1503 			REG_SSI_SRMSK / sizeof(uint32_t) + 1;
1504 	}
1505 
1506 	if (ssi->has_ipg_clk_name)
1507 		ssi->regs = devm_regmap_init_mmio_clk(dev, "ipg", iomem,
1508 						      &regconfig);
1509 	else
1510 		ssi->regs = devm_regmap_init_mmio(dev, iomem, &regconfig);
1511 	if (IS_ERR(ssi->regs)) {
1512 		dev_err(dev, "failed to init register map\n");
1513 		return PTR_ERR(ssi->regs);
1514 	}
1515 
1516 	ssi->irq = platform_get_irq(pdev, 0);
1517 	if (ssi->irq < 0)
1518 		return ssi->irq;
1519 
1520 	/* Set software limitations for synchronous mode except AC97 */
1521 	if (ssi->synchronous && !fsl_ssi_is_ac97(ssi)) {
1522 		ssi->cpu_dai_drv.symmetric_rates = 1;
1523 		ssi->cpu_dai_drv.symmetric_channels = 1;
1524 		ssi->cpu_dai_drv.symmetric_samplebits = 1;
1525 	}
1526 
1527 	/*
1528 	 * Configure TX and RX DMA watermarks -- when to send a DMA request
1529 	 *
1530 	 * Values should be tested to avoid FIFO under/over run. Set maxburst
1531 	 * to fifo_watermark to maxiumize DMA transaction to reduce overhead.
1532 	 */
1533 	switch (ssi->fifo_depth) {
1534 	case 15:
1535 		/*
1536 		 * Set to 8 as a balanced configuration -- When TX FIFO has 8
1537 		 * empty slots, send a DMA request to fill these 8 slots. The
1538 		 * remaining 7 slots should be able to allow DMA to finish the
1539 		 * transaction before TX FIFO underruns; Same applies to RX.
1540 		 *
1541 		 * Tested with cases running at 48kHz @ 16 bits x 16 channels
1542 		 */
1543 		ssi->fifo_watermark = 8;
1544 		ssi->dma_maxburst = 8;
1545 		break;
1546 	case 8:
1547 	default:
1548 		/* Safely use old watermark configurations for older chips */
1549 		ssi->fifo_watermark = ssi->fifo_depth - 2;
1550 		ssi->dma_maxburst = ssi->fifo_depth - 2;
1551 		break;
1552 	}
1553 
1554 	dev_set_drvdata(dev, ssi);
1555 
1556 	if (ssi->soc->imx) {
1557 		ret = fsl_ssi_imx_probe(pdev, ssi, iomem);
1558 		if (ret)
1559 			return ret;
1560 	}
1561 
1562 	if (fsl_ssi_is_ac97(ssi)) {
1563 		mutex_init(&ssi->ac97_reg_lock);
1564 		ret = snd_soc_set_ac97_ops_of_reset(&fsl_ssi_ac97_ops, pdev);
1565 		if (ret) {
1566 			dev_err(dev, "failed to set AC'97 ops\n");
1567 			goto error_ac97_ops;
1568 		}
1569 	}
1570 
1571 	ret = devm_snd_soc_register_component(dev, &fsl_ssi_component,
1572 					      &ssi->cpu_dai_drv, 1);
1573 	if (ret) {
1574 		dev_err(dev, "failed to register DAI: %d\n", ret);
1575 		goto error_asoc_register;
1576 	}
1577 
1578 	if (ssi->use_dma) {
1579 		ret = devm_request_irq(dev, ssi->irq, fsl_ssi_isr, 0,
1580 				       dev_name(dev), ssi);
1581 		if (ret < 0) {
1582 			dev_err(dev, "failed to claim irq %u\n", ssi->irq);
1583 			goto error_asoc_register;
1584 		}
1585 	}
1586 
1587 	fsl_ssi_debugfs_create(&ssi->dbg_stats, dev);
1588 
1589 	/* Initially configures SSI registers */
1590 	fsl_ssi_hw_init(ssi);
1591 
1592 	/* Register a platform device for older bindings or AC97 */
1593 	if (ssi->card_name[0]) {
1594 		struct device *parent = dev;
1595 		/*
1596 		 * Do not set SSI dev as the parent of AC97 CODEC device since
1597 		 * it does not have a DT node. Otherwise ASoC core will assume
1598 		 * CODEC has the same DT node as the SSI, so it may bypass the
1599 		 * dai_probe() of SSI and then cause NULL DMA data pointers.
1600 		 */
1601 		if (fsl_ssi_is_ac97(ssi))
1602 			parent = NULL;
1603 
1604 		ssi->card_pdev = platform_device_register_data(parent,
1605 				ssi->card_name, ssi->card_idx, NULL, 0);
1606 		if (IS_ERR(ssi->card_pdev)) {
1607 			ret = PTR_ERR(ssi->card_pdev);
1608 			dev_err(dev, "failed to register %s: %d\n",
1609 				ssi->card_name, ret);
1610 			goto error_sound_card;
1611 		}
1612 	}
1613 
1614 	return 0;
1615 
1616 error_sound_card:
1617 	fsl_ssi_debugfs_remove(&ssi->dbg_stats);
1618 error_asoc_register:
1619 	if (fsl_ssi_is_ac97(ssi))
1620 		snd_soc_set_ac97_ops(NULL);
1621 error_ac97_ops:
1622 	if (fsl_ssi_is_ac97(ssi))
1623 		mutex_destroy(&ssi->ac97_reg_lock);
1624 
1625 	if (ssi->soc->imx)
1626 		fsl_ssi_imx_clean(pdev, ssi);
1627 
1628 	return ret;
1629 }
1630 
1631 static int fsl_ssi_remove(struct platform_device *pdev)
1632 {
1633 	struct fsl_ssi *ssi = dev_get_drvdata(&pdev->dev);
1634 
1635 	fsl_ssi_debugfs_remove(&ssi->dbg_stats);
1636 
1637 	if (ssi->card_pdev)
1638 		platform_device_unregister(ssi->card_pdev);
1639 
1640 	/* Clean up SSI registers */
1641 	fsl_ssi_hw_clean(ssi);
1642 
1643 	if (ssi->soc->imx)
1644 		fsl_ssi_imx_clean(pdev, ssi);
1645 
1646 	if (fsl_ssi_is_ac97(ssi)) {
1647 		snd_soc_set_ac97_ops(NULL);
1648 		mutex_destroy(&ssi->ac97_reg_lock);
1649 	}
1650 
1651 	return 0;
1652 }
1653 
1654 #ifdef CONFIG_PM_SLEEP
1655 static int fsl_ssi_suspend(struct device *dev)
1656 {
1657 	struct fsl_ssi *ssi = dev_get_drvdata(dev);
1658 	struct regmap *regs = ssi->regs;
1659 
1660 	regmap_read(regs, REG_SSI_SFCSR, &ssi->regcache_sfcsr);
1661 	regmap_read(regs, REG_SSI_SACNT, &ssi->regcache_sacnt);
1662 
1663 	regcache_cache_only(regs, true);
1664 	regcache_mark_dirty(regs);
1665 
1666 	return 0;
1667 }
1668 
1669 static int fsl_ssi_resume(struct device *dev)
1670 {
1671 	struct fsl_ssi *ssi = dev_get_drvdata(dev);
1672 	struct regmap *regs = ssi->regs;
1673 
1674 	regcache_cache_only(regs, false);
1675 
1676 	regmap_update_bits(regs, REG_SSI_SFCSR,
1677 			   SSI_SFCSR_RFWM1_MASK | SSI_SFCSR_TFWM1_MASK |
1678 			   SSI_SFCSR_RFWM0_MASK | SSI_SFCSR_TFWM0_MASK,
1679 			   ssi->regcache_sfcsr);
1680 	regmap_write(regs, REG_SSI_SACNT, ssi->regcache_sacnt);
1681 
1682 	return regcache_sync(regs);
1683 }
1684 #endif /* CONFIG_PM_SLEEP */
1685 
1686 static const struct dev_pm_ops fsl_ssi_pm = {
1687 	SET_SYSTEM_SLEEP_PM_OPS(fsl_ssi_suspend, fsl_ssi_resume)
1688 };
1689 
1690 static struct platform_driver fsl_ssi_driver = {
1691 	.driver = {
1692 		.name = "fsl-ssi-dai",
1693 		.of_match_table = fsl_ssi_ids,
1694 		.pm = &fsl_ssi_pm,
1695 	},
1696 	.probe = fsl_ssi_probe,
1697 	.remove = fsl_ssi_remove,
1698 };
1699 
1700 module_platform_driver(fsl_ssi_driver);
1701 
1702 MODULE_ALIAS("platform:fsl-ssi-dai");
1703 MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
1704 MODULE_DESCRIPTION("Freescale Synchronous Serial Interface (SSI) ASoC Driver");
1705 MODULE_LICENSE("GPL v2");
1706