xref: /linux/sound/soc/fsl/fsl_ssi.c (revision 8137a49e1567726eb10fcf55ad141ac19804ca6b)
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  * struct fsl_ssi - per-SSI private data
207  * @regs: Pointer to the regmap registers
208  * @irq: IRQ of this SSI
209  * @cpu_dai_drv: CPU DAI driver for this device
210  * @dai_fmt: DAI configuration this device is currently used with
211  * @streams: Mask of current active streams: BIT(TX) and BIT(RX)
212  * @i2s_net: I2S and Network mode configurations of SCR register
213  *           (this is the initial settings based on the DAI format)
214  * @synchronous: Use synchronous mode - both of TX and RX use STCK and SFCK
215  * @use_dma: DMA is used or FIQ with stream filter
216  * @use_dual_fifo: DMA with support for dual FIFO mode
217  * @has_ipg_clk_name: If "ipg" is in the clock name list of device tree
218  * @fifo_depth: Depth of the SSI FIFOs
219  * @slot_width: Width of each DAI slot
220  * @slots: Number of slots
221  * @regvals: Specific RX/TX register settings
222  * @clk: Clock source to access register
223  * @baudclk: Clock source to generate bit and frame-sync clocks
224  * @baudclk_streams: Active streams that are using baudclk
225  * @regcache_sfcsr: Cache sfcsr register value during suspend and resume
226  * @regcache_sacnt: Cache sacnt register value during suspend and resume
227  * @dma_params_tx: DMA transmit parameters
228  * @dma_params_rx: DMA receive parameters
229  * @ssi_phys: physical address of the SSI registers
230  * @fiq_params: FIQ stream filtering parameters
231  * @card_pdev: Platform_device pointer to register a sound card for PowerPC or
232  *             to register a CODEC platform device for AC97
233  * @card_name: Platform_device name to register a sound card for PowerPC or
234  *             to register a CODEC platform device for AC97
235  * @card_idx: The index of SSI to register a sound card for PowerPC or
236  *            to register a CODEC platform device for AC97
237  * @dbg_stats: Debugging statistics
238  * @soc: SoC specific data
239  * @dev: Pointer to &pdev->dev
240  * @fifo_watermark: The FIFO watermark setting. Notifies DMA when there are
241  *                  @fifo_watermark or fewer words in TX fifo or
242  *                  @fifo_watermark or more empty words in RX fifo.
243  * @dma_maxburst: Max number of words to transfer in one go. So far,
244  *                this is always the same as fifo_watermark.
245  * @ac97_reg_lock: Mutex lock to serialize AC97 register access operations
246  */
247 struct fsl_ssi {
248 	struct regmap *regs;
249 	int irq;
250 	struct snd_soc_dai_driver cpu_dai_drv;
251 
252 	unsigned int dai_fmt;
253 	u8 streams;
254 	u8 i2s_net;
255 	bool synchronous;
256 	bool use_dma;
257 	bool use_dual_fifo;
258 	bool has_ipg_clk_name;
259 	unsigned int fifo_depth;
260 	unsigned int slot_width;
261 	unsigned int slots;
262 	struct fsl_ssi_regvals regvals[2];
263 
264 	struct clk *clk;
265 	struct clk *baudclk;
266 	unsigned int baudclk_streams;
267 
268 	u32 regcache_sfcsr;
269 	u32 regcache_sacnt;
270 
271 	struct snd_dmaengine_dai_dma_data dma_params_tx;
272 	struct snd_dmaengine_dai_dma_data dma_params_rx;
273 	dma_addr_t ssi_phys;
274 
275 	struct imx_pcm_fiq_params fiq_params;
276 
277 	struct platform_device *card_pdev;
278 	char card_name[32];
279 	u32 card_idx;
280 
281 	struct fsl_ssi_dbg dbg_stats;
282 
283 	const struct fsl_ssi_soc_data *soc;
284 	struct device *dev;
285 
286 	u32 fifo_watermark;
287 	u32 dma_maxburst;
288 
289 	struct mutex ac97_reg_lock;
290 };
291 
292 /*
293  * SoC specific data
294  *
295  * Notes:
296  * 1) SSI in earlier SoCS has critical bits in control registers that
297  *    cannot be changed after SSI starts running -- a software reset
298  *    (set SSIEN to 0) is required to change their values. So adding
299  *    an offline_config flag for these SoCs.
300  * 2) SDMA is available since imx35. However, imx35 does not support
301  *    DMA bits changing when SSI is running, so set offline_config.
302  * 3) imx51 and later versions support register configurations when
303  *    SSI is running (SSIEN); For these versions, DMA needs to be
304  *    configured before SSI sends DMA request to avoid an undefined
305  *    DMA request on the SDMA side.
306  */
307 
308 static struct fsl_ssi_soc_data fsl_ssi_mpc8610 = {
309 	.imx = false,
310 	.offline_config = true,
311 	.sisr_write_mask = SSI_SISR_RFRC | SSI_SISR_TFRC |
312 			   SSI_SISR_ROE0 | SSI_SISR_ROE1 |
313 			   SSI_SISR_TUE0 | SSI_SISR_TUE1,
314 };
315 
316 static struct fsl_ssi_soc_data fsl_ssi_imx21 = {
317 	.imx = true,
318 	.imx21regs = true,
319 	.offline_config = true,
320 	.sisr_write_mask = 0,
321 };
322 
323 static struct fsl_ssi_soc_data fsl_ssi_imx35 = {
324 	.imx = true,
325 	.offline_config = true,
326 	.sisr_write_mask = SSI_SISR_RFRC | SSI_SISR_TFRC |
327 			   SSI_SISR_ROE0 | SSI_SISR_ROE1 |
328 			   SSI_SISR_TUE0 | SSI_SISR_TUE1,
329 };
330 
331 static struct fsl_ssi_soc_data fsl_ssi_imx51 = {
332 	.imx = true,
333 	.offline_config = false,
334 	.sisr_write_mask = SSI_SISR_ROE0 | SSI_SISR_ROE1 |
335 			   SSI_SISR_TUE0 | SSI_SISR_TUE1,
336 };
337 
338 static const struct of_device_id fsl_ssi_ids[] = {
339 	{ .compatible = "fsl,mpc8610-ssi", .data = &fsl_ssi_mpc8610 },
340 	{ .compatible = "fsl,imx51-ssi", .data = &fsl_ssi_imx51 },
341 	{ .compatible = "fsl,imx35-ssi", .data = &fsl_ssi_imx35 },
342 	{ .compatible = "fsl,imx21-ssi", .data = &fsl_ssi_imx21 },
343 	{}
344 };
345 MODULE_DEVICE_TABLE(of, fsl_ssi_ids);
346 
347 static bool fsl_ssi_is_ac97(struct fsl_ssi *ssi)
348 {
349 	return (ssi->dai_fmt & SND_SOC_DAIFMT_FORMAT_MASK) ==
350 		SND_SOC_DAIFMT_AC97;
351 }
352 
353 static bool fsl_ssi_is_i2s_master(struct fsl_ssi *ssi)
354 {
355 	return (ssi->dai_fmt & SND_SOC_DAIFMT_MASTER_MASK) ==
356 		SND_SOC_DAIFMT_CBS_CFS;
357 }
358 
359 static bool fsl_ssi_is_i2s_cbm_cfs(struct fsl_ssi *ssi)
360 {
361 	return (ssi->dai_fmt & SND_SOC_DAIFMT_MASTER_MASK) ==
362 		SND_SOC_DAIFMT_CBM_CFS;
363 }
364 
365 /**
366  * fsl_ssi_isr - Interrupt handler to gather states
367  * @irq: irq number
368  * @dev_id: context
369  */
370 static irqreturn_t fsl_ssi_isr(int irq, void *dev_id)
371 {
372 	struct fsl_ssi *ssi = dev_id;
373 	struct regmap *regs = ssi->regs;
374 	u32 sisr, sisr2;
375 
376 	regmap_read(regs, REG_SSI_SISR, &sisr);
377 
378 	sisr2 = sisr & ssi->soc->sisr_write_mask;
379 	/* Clear the bits that we set */
380 	if (sisr2)
381 		regmap_write(regs, REG_SSI_SISR, sisr2);
382 
383 	fsl_ssi_dbg_isr(&ssi->dbg_stats, sisr);
384 
385 	return IRQ_HANDLED;
386 }
387 
388 /**
389  * fsl_ssi_config_enable - Set SCR, SIER, STCR and SRCR registers with
390  * cached values in regvals
391  * @ssi: SSI context
392  * @tx: direction
393  *
394  * Notes:
395  * 1) For offline_config SoCs, enable all necessary bits of both streams
396  *    when 1st stream starts, even if the opposite stream will not start
397  * 2) It also clears FIFO before setting regvals; SOR is safe to set online
398  */
399 static void fsl_ssi_config_enable(struct fsl_ssi *ssi, bool tx)
400 {
401 	struct fsl_ssi_regvals *vals = ssi->regvals;
402 	int dir = tx ? TX : RX;
403 	u32 sier, srcr, stcr;
404 
405 	/* Clear dirty data in the FIFO; It also prevents channel slipping */
406 	regmap_update_bits(ssi->regs, REG_SSI_SOR,
407 			   SSI_SOR_xX_CLR(tx), SSI_SOR_xX_CLR(tx));
408 
409 	/*
410 	 * On offline_config SoCs, SxCR and SIER are already configured when
411 	 * the previous stream started. So skip all SxCR and SIER settings
412 	 * to prevent online reconfigurations, then jump to set SCR directly
413 	 */
414 	if (ssi->soc->offline_config && ssi->streams)
415 		goto enable_scr;
416 
417 	if (ssi->soc->offline_config) {
418 		/*
419 		 * Online reconfiguration not supported, so enable all bits for
420 		 * both streams at once to avoid necessity of reconfigurations
421 		 */
422 		srcr = vals[RX].srcr | vals[TX].srcr;
423 		stcr = vals[RX].stcr | vals[TX].stcr;
424 		sier = vals[RX].sier | vals[TX].sier;
425 	} else {
426 		/* Otherwise, only set bits for the current stream */
427 		srcr = vals[dir].srcr;
428 		stcr = vals[dir].stcr;
429 		sier = vals[dir].sier;
430 	}
431 
432 	/* Configure SRCR, STCR and SIER at once */
433 	regmap_update_bits(ssi->regs, REG_SSI_SRCR, srcr, srcr);
434 	regmap_update_bits(ssi->regs, REG_SSI_STCR, stcr, stcr);
435 	regmap_update_bits(ssi->regs, REG_SSI_SIER, sier, sier);
436 
437 enable_scr:
438 	/*
439 	 * Start DMA before setting TE to avoid FIFO underrun
440 	 * which may cause a channel slip or a channel swap
441 	 *
442 	 * TODO: FIQ cases might also need this upon testing
443 	 */
444 	if (ssi->use_dma && tx) {
445 		int try = 100;
446 		u32 sfcsr;
447 
448 		/* Enable SSI first to send TX DMA request */
449 		regmap_update_bits(ssi->regs, REG_SSI_SCR,
450 				   SSI_SCR_SSIEN, SSI_SCR_SSIEN);
451 
452 		/* Busy wait until TX FIFO not empty -- DMA working */
453 		do {
454 			regmap_read(ssi->regs, REG_SSI_SFCSR, &sfcsr);
455 			if (SSI_SFCSR_TFCNT0(sfcsr))
456 				break;
457 		} while (--try);
458 
459 		/* FIFO still empty -- something might be wrong */
460 		if (!SSI_SFCSR_TFCNT0(sfcsr))
461 			dev_warn(ssi->dev, "Timeout waiting TX FIFO filling\n");
462 	}
463 	/* Enable all remaining bits in SCR */
464 	regmap_update_bits(ssi->regs, REG_SSI_SCR,
465 			   vals[dir].scr, vals[dir].scr);
466 
467 	/* Log the enabled stream to the mask */
468 	ssi->streams |= BIT(dir);
469 }
470 
471 /*
472  * Exclude bits that are used by the opposite stream
473  *
474  * When both streams are active, disabling some bits for the current stream
475  * might break the other stream if these bits are used by it.
476  *
477  * @vals : regvals of the current stream
478  * @avals: regvals of the opposite stream
479  * @aactive: active state of the opposite stream
480  *
481  *  1) XOR vals and avals to get the differences if the other stream is active;
482  *     Otherwise, return current vals if the other stream is not active
483  *  2) AND the result of 1) with the current vals
484  */
485 #define _ssi_xor_shared_bits(vals, avals, aactive) \
486 	((vals) ^ ((avals) * (aactive)))
487 
488 #define ssi_excl_shared_bits(vals, avals, aactive) \
489 	((vals) & _ssi_xor_shared_bits(vals, avals, aactive))
490 
491 /**
492  * fsl_ssi_config_disable - Unset SCR, SIER, STCR and SRCR registers
493  * with cached values in regvals
494  * @ssi: SSI context
495  * @tx: direction
496  *
497  * Notes:
498  * 1) For offline_config SoCs, to avoid online reconfigurations, disable all
499  *    bits of both streams at once when the last stream is abort to end
500  * 2) It also clears FIFO after unsetting regvals; SOR is safe to set online
501  */
502 static void fsl_ssi_config_disable(struct fsl_ssi *ssi, bool tx)
503 {
504 	struct fsl_ssi_regvals *vals, *avals;
505 	u32 sier, srcr, stcr, scr;
506 	int adir = tx ? RX : TX;
507 	int dir = tx ? TX : RX;
508 	bool aactive;
509 
510 	/* Check if the opposite stream is active */
511 	aactive = ssi->streams & BIT(adir);
512 
513 	vals = &ssi->regvals[dir];
514 
515 	/* Get regvals of the opposite stream to keep opposite stream safe */
516 	avals = &ssi->regvals[adir];
517 
518 	/*
519 	 * To keep the other stream safe, exclude shared bits between
520 	 * both streams, and get safe bits to disable current stream
521 	 */
522 	scr = ssi_excl_shared_bits(vals->scr, avals->scr, aactive);
523 
524 	/* Disable safe bits of SCR register for the current stream */
525 	regmap_update_bits(ssi->regs, REG_SSI_SCR, scr, 0);
526 
527 	/* Log the disabled stream to the mask */
528 	ssi->streams &= ~BIT(dir);
529 
530 	/*
531 	 * On offline_config SoCs, if the other stream is active, skip
532 	 * SxCR and SIER settings to prevent online reconfigurations
533 	 */
534 	if (ssi->soc->offline_config && aactive)
535 		goto fifo_clear;
536 
537 	if (ssi->soc->offline_config) {
538 		/* Now there is only current stream active, disable all bits */
539 		srcr = vals->srcr | avals->srcr;
540 		stcr = vals->stcr | avals->stcr;
541 		sier = vals->sier | avals->sier;
542 	} else {
543 		/*
544 		 * To keep the other stream safe, exclude shared bits between
545 		 * both streams, and get safe bits to disable current stream
546 		 */
547 		sier = ssi_excl_shared_bits(vals->sier, avals->sier, aactive);
548 		srcr = ssi_excl_shared_bits(vals->srcr, avals->srcr, aactive);
549 		stcr = ssi_excl_shared_bits(vals->stcr, avals->stcr, aactive);
550 	}
551 
552 	/* Clear configurations of SRCR, STCR and SIER at once */
553 	regmap_update_bits(ssi->regs, REG_SSI_SRCR, srcr, 0);
554 	regmap_update_bits(ssi->regs, REG_SSI_STCR, stcr, 0);
555 	regmap_update_bits(ssi->regs, REG_SSI_SIER, sier, 0);
556 
557 fifo_clear:
558 	/* Clear remaining data in the FIFO */
559 	regmap_update_bits(ssi->regs, REG_SSI_SOR,
560 			   SSI_SOR_xX_CLR(tx), SSI_SOR_xX_CLR(tx));
561 }
562 
563 static void fsl_ssi_tx_ac97_saccst_setup(struct fsl_ssi *ssi)
564 {
565 	struct regmap *regs = ssi->regs;
566 
567 	/* no SACC{ST,EN,DIS} regs on imx21-class SSI */
568 	if (!ssi->soc->imx21regs) {
569 		/* Disable all channel slots */
570 		regmap_write(regs, REG_SSI_SACCDIS, 0xff);
571 		/* Enable slots 3 & 4 -- PCM Playback Left & Right channels */
572 		regmap_write(regs, REG_SSI_SACCEN, 0x300);
573 	}
574 }
575 
576 /**
577  * fsl_ssi_setup_regvals - Cache critical bits of SIER, SRCR, STCR and
578  * SCR to later set them safely
579  * @ssi: SSI context
580  */
581 static void fsl_ssi_setup_regvals(struct fsl_ssi *ssi)
582 {
583 	struct fsl_ssi_regvals *vals = ssi->regvals;
584 
585 	vals[RX].sier = SSI_SIER_RFF0_EN | FSLSSI_SIER_DBG_RX_FLAGS;
586 	vals[RX].srcr = SSI_SRCR_RFEN0;
587 	vals[RX].scr = SSI_SCR_SSIEN | SSI_SCR_RE;
588 	vals[TX].sier = SSI_SIER_TFE0_EN | FSLSSI_SIER_DBG_TX_FLAGS;
589 	vals[TX].stcr = SSI_STCR_TFEN0;
590 	vals[TX].scr = SSI_SCR_SSIEN | SSI_SCR_TE;
591 
592 	/* AC97 has already enabled SSIEN, RE and TE, so ignore them */
593 	if (fsl_ssi_is_ac97(ssi))
594 		vals[RX].scr = vals[TX].scr = 0;
595 
596 	if (ssi->use_dual_fifo) {
597 		vals[RX].srcr |= SSI_SRCR_RFEN1;
598 		vals[TX].stcr |= SSI_STCR_TFEN1;
599 	}
600 
601 	if (ssi->use_dma) {
602 		vals[RX].sier |= SSI_SIER_RDMAE;
603 		vals[TX].sier |= SSI_SIER_TDMAE;
604 	} else {
605 		vals[RX].sier |= SSI_SIER_RIE;
606 		vals[TX].sier |= SSI_SIER_TIE;
607 	}
608 }
609 
610 static void fsl_ssi_setup_ac97(struct fsl_ssi *ssi)
611 {
612 	struct regmap *regs = ssi->regs;
613 
614 	/* Setup the clock control register */
615 	regmap_write(regs, REG_SSI_STCCR, SSI_SxCCR_WL(17) | SSI_SxCCR_DC(13));
616 	regmap_write(regs, REG_SSI_SRCCR, SSI_SxCCR_WL(17) | SSI_SxCCR_DC(13));
617 
618 	/* Enable AC97 mode and startup the SSI */
619 	regmap_write(regs, REG_SSI_SACNT, SSI_SACNT_AC97EN | SSI_SACNT_FV);
620 
621 	/* AC97 has to communicate with codec before starting a stream */
622 	regmap_update_bits(regs, REG_SSI_SCR,
623 			   SSI_SCR_SSIEN | SSI_SCR_TE | SSI_SCR_RE,
624 			   SSI_SCR_SSIEN | SSI_SCR_TE | SSI_SCR_RE);
625 
626 	regmap_write(regs, REG_SSI_SOR, SSI_SOR_WAIT(3));
627 }
628 
629 static int fsl_ssi_startup(struct snd_pcm_substream *substream,
630 			   struct snd_soc_dai *dai)
631 {
632 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
633 	struct fsl_ssi *ssi = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
634 	int ret;
635 
636 	ret = clk_prepare_enable(ssi->clk);
637 	if (ret)
638 		return ret;
639 
640 	/*
641 	 * When using dual fifo mode, it is safer to ensure an even period
642 	 * size. If appearing to an odd number while DMA always starts its
643 	 * task from fifo0, fifo1 would be neglected at the end of each
644 	 * period. But SSI would still access fifo1 with an invalid data.
645 	 */
646 	if (ssi->use_dual_fifo)
647 		snd_pcm_hw_constraint_step(substream->runtime, 0,
648 					   SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 2);
649 
650 	return 0;
651 }
652 
653 static void fsl_ssi_shutdown(struct snd_pcm_substream *substream,
654 			     struct snd_soc_dai *dai)
655 {
656 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
657 	struct fsl_ssi *ssi = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
658 
659 	clk_disable_unprepare(ssi->clk);
660 }
661 
662 /**
663  * fsl_ssi_set_bclk - Configure Digital Audio Interface bit clock
664  * @substream: ASoC substream
665  * @dai: pointer to DAI
666  * @hw_params: pointers to hw_params
667  *
668  * Notes: This function can be only called when using SSI as DAI master
669  *
670  * Quick instruction for parameters:
671  * freq: Output BCLK frequency = samplerate * slots * slot_width
672  *       (In 2-channel I2S Master mode, slot_width is fixed 32)
673  */
674 static int fsl_ssi_set_bclk(struct snd_pcm_substream *substream,
675 			    struct snd_soc_dai *dai,
676 			    struct snd_pcm_hw_params *hw_params)
677 {
678 	bool tx2, tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
679 	struct fsl_ssi *ssi = snd_soc_dai_get_drvdata(dai);
680 	struct regmap *regs = ssi->regs;
681 	u32 pm = 999, div2, psr, stccr, mask, afreq, factor, i;
682 	unsigned long clkrate, baudrate, tmprate;
683 	unsigned int channels = params_channels(hw_params);
684 	unsigned int slot_width = params_width(hw_params);
685 	unsigned int slots = 2;
686 	u64 sub, savesub = 100000;
687 	unsigned int freq;
688 	bool baudclk_is_used;
689 	int ret;
690 
691 	/* Override slots and slot_width if being specifically set... */
692 	if (ssi->slots)
693 		slots = ssi->slots;
694 	if (ssi->slot_width)
695 		slot_width = ssi->slot_width;
696 
697 	/* ...but force 32 bits for stereo audio using I2S Master Mode */
698 	if (channels == 2 &&
699 	    (ssi->i2s_net & SSI_SCR_I2S_MODE_MASK) == SSI_SCR_I2S_MODE_MASTER)
700 		slot_width = 32;
701 
702 	/* Generate bit clock based on the slot number and slot width */
703 	freq = slots * slot_width * params_rate(hw_params);
704 
705 	/* Don't apply it to any non-baudclk circumstance */
706 	if (IS_ERR(ssi->baudclk))
707 		return -EINVAL;
708 
709 	/*
710 	 * Hardware limitation: The bclk rate must be
711 	 * never greater than 1/5 IPG clock rate
712 	 */
713 	if (freq * 5 > clk_get_rate(ssi->clk)) {
714 		dev_err(dai->dev, "bitclk > ipgclk / 5\n");
715 		return -EINVAL;
716 	}
717 
718 	baudclk_is_used = ssi->baudclk_streams & ~(BIT(substream->stream));
719 
720 	/* It should be already enough to divide clock by setting pm alone */
721 	psr = 0;
722 	div2 = 0;
723 
724 	factor = (div2 + 1) * (7 * psr + 1) * 2;
725 
726 	for (i = 0; i < 255; i++) {
727 		tmprate = freq * factor * (i + 1);
728 
729 		if (baudclk_is_used)
730 			clkrate = clk_get_rate(ssi->baudclk);
731 		else
732 			clkrate = clk_round_rate(ssi->baudclk, tmprate);
733 
734 		clkrate /= factor;
735 		afreq = clkrate / (i + 1);
736 
737 		if (freq == afreq)
738 			sub = 0;
739 		else if (freq / afreq == 1)
740 			sub = freq - afreq;
741 		else if (afreq / freq == 1)
742 			sub = afreq - freq;
743 		else
744 			continue;
745 
746 		/* Calculate the fraction */
747 		sub *= 100000;
748 		do_div(sub, freq);
749 
750 		if (sub < savesub && !(i == 0)) {
751 			baudrate = tmprate;
752 			savesub = sub;
753 			pm = i;
754 		}
755 
756 		/* We are lucky */
757 		if (savesub == 0)
758 			break;
759 	}
760 
761 	/* No proper pm found if it is still remaining the initial value */
762 	if (pm == 999) {
763 		dev_err(dai->dev, "failed to handle the required sysclk\n");
764 		return -EINVAL;
765 	}
766 
767 	stccr = SSI_SxCCR_PM(pm + 1);
768 	mask = SSI_SxCCR_PM_MASK | SSI_SxCCR_DIV2 | SSI_SxCCR_PSR;
769 
770 	/* STCCR is used for RX in synchronous mode */
771 	tx2 = tx || ssi->synchronous;
772 	regmap_update_bits(regs, REG_SSI_SxCCR(tx2), mask, stccr);
773 
774 	if (!baudclk_is_used) {
775 		ret = clk_set_rate(ssi->baudclk, baudrate);
776 		if (ret) {
777 			dev_err(dai->dev, "failed to set baudclk rate\n");
778 			return -EINVAL;
779 		}
780 	}
781 
782 	return 0;
783 }
784 
785 /**
786  * fsl_ssi_hw_params - Configure SSI based on PCM hardware parameters
787  * @substream: ASoC substream
788  * @hw_params: pointers to hw_params
789  * @dai: pointer to DAI
790  *
791  * Notes:
792  * 1) SxCCR.WL bits are critical bits that require SSI to be temporarily
793  *    disabled on offline_config SoCs. Even for online configurable SoCs
794  *    running in synchronous mode (both TX and RX use STCCR), it is not
795  *    safe to re-configure them when both two streams start running.
796  * 2) SxCCR.PM, SxCCR.DIV2 and SxCCR.PSR bits will be configured in the
797  *    fsl_ssi_set_bclk() if SSI is the DAI clock master.
798  */
799 static int fsl_ssi_hw_params(struct snd_pcm_substream *substream,
800 			     struct snd_pcm_hw_params *hw_params,
801 			     struct snd_soc_dai *dai)
802 {
803 	bool tx2, tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
804 	struct fsl_ssi *ssi = snd_soc_dai_get_drvdata(dai);
805 	struct regmap *regs = ssi->regs;
806 	unsigned int channels = params_channels(hw_params);
807 	unsigned int sample_size = params_width(hw_params);
808 	u32 wl = SSI_SxCCR_WL(sample_size);
809 	int ret;
810 
811 	if (fsl_ssi_is_i2s_master(ssi)) {
812 		ret = fsl_ssi_set_bclk(substream, dai, hw_params);
813 		if (ret)
814 			return ret;
815 
816 		/* Do not enable the clock if it is already enabled */
817 		if (!(ssi->baudclk_streams & BIT(substream->stream))) {
818 			ret = clk_prepare_enable(ssi->baudclk);
819 			if (ret)
820 				return ret;
821 
822 			ssi->baudclk_streams |= BIT(substream->stream);
823 		}
824 	}
825 
826 	/*
827 	 * SSI is properly configured if it is enabled and running in
828 	 * the synchronous mode; Note that AC97 mode is an exception
829 	 * that should set separate configurations for STCCR and SRCCR
830 	 * despite running in the synchronous mode.
831 	 */
832 	if (ssi->streams && ssi->synchronous)
833 		return 0;
834 
835 	if (!fsl_ssi_is_ac97(ssi)) {
836 		/*
837 		 * Keep the ssi->i2s_net intact while having a local variable
838 		 * to override settings for special use cases. Otherwise, the
839 		 * ssi->i2s_net will lose the settings for regular use cases.
840 		 */
841 		u8 i2s_net = ssi->i2s_net;
842 
843 		/* Normal + Network mode to send 16-bit data in 32-bit frames */
844 		if (fsl_ssi_is_i2s_cbm_cfs(ssi) && sample_size == 16)
845 			i2s_net = SSI_SCR_I2S_MODE_NORMAL | SSI_SCR_NET;
846 
847 		/* Use Normal mode to send mono data at 1st slot of 2 slots */
848 		if (channels == 1)
849 			i2s_net = SSI_SCR_I2S_MODE_NORMAL;
850 
851 		regmap_update_bits(regs, REG_SSI_SCR,
852 				   SSI_SCR_I2S_NET_MASK, i2s_net);
853 	}
854 
855 	/* In synchronous mode, the SSI uses STCCR for capture */
856 	tx2 = tx || ssi->synchronous;
857 	regmap_update_bits(regs, REG_SSI_SxCCR(tx2), SSI_SxCCR_WL_MASK, wl);
858 
859 	return 0;
860 }
861 
862 static int fsl_ssi_hw_free(struct snd_pcm_substream *substream,
863 			   struct snd_soc_dai *dai)
864 {
865 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
866 	struct fsl_ssi *ssi = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
867 
868 	if (fsl_ssi_is_i2s_master(ssi) &&
869 	    ssi->baudclk_streams & BIT(substream->stream)) {
870 		clk_disable_unprepare(ssi->baudclk);
871 		ssi->baudclk_streams &= ~BIT(substream->stream);
872 	}
873 
874 	return 0;
875 }
876 
877 static int _fsl_ssi_set_dai_fmt(struct fsl_ssi *ssi, unsigned int fmt)
878 {
879 	u32 strcr = 0, scr = 0, stcr, srcr, mask;
880 	unsigned int slots;
881 
882 	ssi->dai_fmt = fmt;
883 
884 	/* Synchronize frame sync clock for TE to avoid data slipping */
885 	scr |= SSI_SCR_SYNC_TX_FS;
886 
887 	/* Set to default shifting settings: LSB_ALIGNED */
888 	strcr |= SSI_STCR_TXBIT0;
889 
890 	/* Use Network mode as default */
891 	ssi->i2s_net = SSI_SCR_NET;
892 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
893 	case SND_SOC_DAIFMT_I2S:
894 		switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
895 		case SND_SOC_DAIFMT_CBS_CFS:
896 			if (IS_ERR(ssi->baudclk)) {
897 				dev_err(ssi->dev,
898 					"missing baudclk for master mode\n");
899 				return -EINVAL;
900 			}
901 			fallthrough;
902 		case SND_SOC_DAIFMT_CBM_CFS:
903 			ssi->i2s_net |= SSI_SCR_I2S_MODE_MASTER;
904 			break;
905 		case SND_SOC_DAIFMT_CBM_CFM:
906 			ssi->i2s_net |= SSI_SCR_I2S_MODE_SLAVE;
907 			break;
908 		default:
909 			return -EINVAL;
910 		}
911 
912 		slots = ssi->slots ? : 2;
913 		regmap_update_bits(ssi->regs, REG_SSI_STCCR,
914 				   SSI_SxCCR_DC_MASK, SSI_SxCCR_DC(slots));
915 		regmap_update_bits(ssi->regs, REG_SSI_SRCCR,
916 				   SSI_SxCCR_DC_MASK, SSI_SxCCR_DC(slots));
917 
918 		/* Data on rising edge of bclk, frame low, 1clk before data */
919 		strcr |= SSI_STCR_TFSI | SSI_STCR_TSCKP | SSI_STCR_TEFS;
920 		break;
921 	case SND_SOC_DAIFMT_LEFT_J:
922 		/* Data on rising edge of bclk, frame high */
923 		strcr |= SSI_STCR_TSCKP;
924 		break;
925 	case SND_SOC_DAIFMT_DSP_A:
926 		/* Data on rising edge of bclk, frame high, 1clk before data */
927 		strcr |= SSI_STCR_TFSL | SSI_STCR_TSCKP | SSI_STCR_TEFS;
928 		break;
929 	case SND_SOC_DAIFMT_DSP_B:
930 		/* Data on rising edge of bclk, frame high */
931 		strcr |= SSI_STCR_TFSL | SSI_STCR_TSCKP;
932 		break;
933 	case SND_SOC_DAIFMT_AC97:
934 		/* Data on falling edge of bclk, frame high, 1clk before data */
935 		strcr |= SSI_STCR_TEFS;
936 		break;
937 	default:
938 		return -EINVAL;
939 	}
940 
941 	scr |= ssi->i2s_net;
942 
943 	/* DAI clock inversion */
944 	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
945 	case SND_SOC_DAIFMT_NB_NF:
946 		/* Nothing to do for both normal cases */
947 		break;
948 	case SND_SOC_DAIFMT_IB_NF:
949 		/* Invert bit clock */
950 		strcr ^= SSI_STCR_TSCKP;
951 		break;
952 	case SND_SOC_DAIFMT_NB_IF:
953 		/* Invert frame clock */
954 		strcr ^= SSI_STCR_TFSI;
955 		break;
956 	case SND_SOC_DAIFMT_IB_IF:
957 		/* Invert both clocks */
958 		strcr ^= SSI_STCR_TSCKP;
959 		strcr ^= SSI_STCR_TFSI;
960 		break;
961 	default:
962 		return -EINVAL;
963 	}
964 
965 	/* DAI clock master masks */
966 	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
967 	case SND_SOC_DAIFMT_CBS_CFS:
968 		/* Output bit and frame sync clocks */
969 		strcr |= SSI_STCR_TFDIR | SSI_STCR_TXDIR;
970 		scr |= SSI_SCR_SYS_CLK_EN;
971 		break;
972 	case SND_SOC_DAIFMT_CBM_CFM:
973 		/* Input bit or frame sync clocks */
974 		break;
975 	case SND_SOC_DAIFMT_CBM_CFS:
976 		/* Input bit clock but output frame sync clock */
977 		strcr |= SSI_STCR_TFDIR;
978 		break;
979 	default:
980 		return -EINVAL;
981 	}
982 
983 	stcr = strcr;
984 	srcr = strcr;
985 
986 	/* Set SYN mode and clear RXDIR bit when using SYN or AC97 mode */
987 	if (ssi->synchronous || fsl_ssi_is_ac97(ssi)) {
988 		srcr &= ~SSI_SRCR_RXDIR;
989 		scr |= SSI_SCR_SYN;
990 	}
991 
992 	mask = SSI_STCR_TFDIR | SSI_STCR_TXDIR | SSI_STCR_TSCKP |
993 	       SSI_STCR_TFSL | SSI_STCR_TFSI | SSI_STCR_TEFS | SSI_STCR_TXBIT0;
994 
995 	regmap_update_bits(ssi->regs, REG_SSI_STCR, mask, stcr);
996 	regmap_update_bits(ssi->regs, REG_SSI_SRCR, mask, srcr);
997 
998 	mask = SSI_SCR_SYNC_TX_FS | SSI_SCR_I2S_MODE_MASK |
999 	       SSI_SCR_SYS_CLK_EN | SSI_SCR_SYN;
1000 	regmap_update_bits(ssi->regs, REG_SSI_SCR, mask, scr);
1001 
1002 	return 0;
1003 }
1004 
1005 /**
1006  * fsl_ssi_set_dai_fmt - Configure Digital Audio Interface (DAI) Format
1007  * @dai: pointer to DAI
1008  * @fmt: format mask
1009  */
1010 static int fsl_ssi_set_dai_fmt(struct snd_soc_dai *dai, unsigned int fmt)
1011 {
1012 	struct fsl_ssi *ssi = snd_soc_dai_get_drvdata(dai);
1013 
1014 	/* AC97 configured DAIFMT earlier in the probe() */
1015 	if (fsl_ssi_is_ac97(ssi))
1016 		return 0;
1017 
1018 	return _fsl_ssi_set_dai_fmt(ssi, fmt);
1019 }
1020 
1021 /**
1022  * fsl_ssi_set_dai_tdm_slot - Set TDM slot number and slot width
1023  * @dai: pointer to DAI
1024  * @tx_mask: mask for TX
1025  * @rx_mask: mask for RX
1026  * @slots: number of slots
1027  * @slot_width: number of bits per slot
1028  */
1029 static int fsl_ssi_set_dai_tdm_slot(struct snd_soc_dai *dai, u32 tx_mask,
1030 				    u32 rx_mask, int slots, int slot_width)
1031 {
1032 	struct fsl_ssi *ssi = snd_soc_dai_get_drvdata(dai);
1033 	struct regmap *regs = ssi->regs;
1034 	u32 val;
1035 
1036 	/* The word length should be 8, 10, 12, 16, 18, 20, 22 or 24 */
1037 	if (slot_width & 1 || slot_width < 8 || slot_width > 24) {
1038 		dev_err(dai->dev, "invalid slot width: %d\n", slot_width);
1039 		return -EINVAL;
1040 	}
1041 
1042 	/* The slot number should be >= 2 if using Network mode or I2S mode */
1043 	if (ssi->i2s_net && slots < 2) {
1044 		dev_err(dai->dev, "slot number should be >= 2 in I2S or NET\n");
1045 		return -EINVAL;
1046 	}
1047 
1048 	regmap_update_bits(regs, REG_SSI_STCCR,
1049 			   SSI_SxCCR_DC_MASK, SSI_SxCCR_DC(slots));
1050 	regmap_update_bits(regs, REG_SSI_SRCCR,
1051 			   SSI_SxCCR_DC_MASK, SSI_SxCCR_DC(slots));
1052 
1053 	/* Save the SCR register value */
1054 	regmap_read(regs, REG_SSI_SCR, &val);
1055 	/* Temporarily enable SSI to allow SxMSKs to be configurable */
1056 	regmap_update_bits(regs, REG_SSI_SCR, SSI_SCR_SSIEN, SSI_SCR_SSIEN);
1057 
1058 	regmap_write(regs, REG_SSI_STMSK, ~tx_mask);
1059 	regmap_write(regs, REG_SSI_SRMSK, ~rx_mask);
1060 
1061 	/* Restore the value of SSIEN bit */
1062 	regmap_update_bits(regs, REG_SSI_SCR, SSI_SCR_SSIEN, val);
1063 
1064 	ssi->slot_width = slot_width;
1065 	ssi->slots = slots;
1066 
1067 	return 0;
1068 }
1069 
1070 /**
1071  * fsl_ssi_trigger - Start or stop SSI and corresponding DMA transaction.
1072  * @substream: ASoC substream
1073  * @cmd: trigger command
1074  * @dai: pointer to DAI
1075  *
1076  * The DMA channel is in external master start and pause mode, which
1077  * means the SSI completely controls the flow of data.
1078  */
1079 static int fsl_ssi_trigger(struct snd_pcm_substream *substream, int cmd,
1080 			   struct snd_soc_dai *dai)
1081 {
1082 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
1083 	struct fsl_ssi *ssi = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
1084 	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
1085 
1086 	switch (cmd) {
1087 	case SNDRV_PCM_TRIGGER_START:
1088 	case SNDRV_PCM_TRIGGER_RESUME:
1089 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1090 		/*
1091 		 * SACCST might be modified via AC Link by a CODEC if it sends
1092 		 * extra bits in their SLOTREQ requests, which'll accidentally
1093 		 * send valid data to slots other than normal playback slots.
1094 		 *
1095 		 * To be safe, configure SACCST right before TX starts.
1096 		 */
1097 		if (tx && fsl_ssi_is_ac97(ssi))
1098 			fsl_ssi_tx_ac97_saccst_setup(ssi);
1099 		fsl_ssi_config_enable(ssi, tx);
1100 		break;
1101 
1102 	case SNDRV_PCM_TRIGGER_STOP:
1103 	case SNDRV_PCM_TRIGGER_SUSPEND:
1104 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1105 		fsl_ssi_config_disable(ssi, tx);
1106 		break;
1107 
1108 	default:
1109 		return -EINVAL;
1110 	}
1111 
1112 	return 0;
1113 }
1114 
1115 static int fsl_ssi_dai_probe(struct snd_soc_dai *dai)
1116 {
1117 	struct fsl_ssi *ssi = snd_soc_dai_get_drvdata(dai);
1118 
1119 	if (ssi->soc->imx && ssi->use_dma)
1120 		snd_soc_dai_init_dma_data(dai, &ssi->dma_params_tx,
1121 					  &ssi->dma_params_rx);
1122 
1123 	return 0;
1124 }
1125 
1126 static const struct snd_soc_dai_ops fsl_ssi_dai_ops = {
1127 	.startup = fsl_ssi_startup,
1128 	.shutdown = fsl_ssi_shutdown,
1129 	.hw_params = fsl_ssi_hw_params,
1130 	.hw_free = fsl_ssi_hw_free,
1131 	.set_fmt = fsl_ssi_set_dai_fmt,
1132 	.set_tdm_slot = fsl_ssi_set_dai_tdm_slot,
1133 	.trigger = fsl_ssi_trigger,
1134 };
1135 
1136 static struct snd_soc_dai_driver fsl_ssi_dai_template = {
1137 	.probe = fsl_ssi_dai_probe,
1138 	.playback = {
1139 		.stream_name = "CPU-Playback",
1140 		.channels_min = 1,
1141 		.channels_max = 32,
1142 		.rates = SNDRV_PCM_RATE_CONTINUOUS,
1143 		.formats = FSLSSI_I2S_FORMATS,
1144 	},
1145 	.capture = {
1146 		.stream_name = "CPU-Capture",
1147 		.channels_min = 1,
1148 		.channels_max = 32,
1149 		.rates = SNDRV_PCM_RATE_CONTINUOUS,
1150 		.formats = FSLSSI_I2S_FORMATS,
1151 	},
1152 	.ops = &fsl_ssi_dai_ops,
1153 };
1154 
1155 static const struct snd_soc_component_driver fsl_ssi_component = {
1156 	.name = "fsl-ssi",
1157 };
1158 
1159 static struct snd_soc_dai_driver fsl_ssi_ac97_dai = {
1160 	.symmetric_channels = 1,
1161 	.probe = fsl_ssi_dai_probe,
1162 	.playback = {
1163 		.stream_name = "AC97 Playback",
1164 		.channels_min = 2,
1165 		.channels_max = 2,
1166 		.rates = SNDRV_PCM_RATE_8000_48000,
1167 		.formats = SNDRV_PCM_FMTBIT_S16 | SNDRV_PCM_FMTBIT_S20,
1168 	},
1169 	.capture = {
1170 		.stream_name = "AC97 Capture",
1171 		.channels_min = 2,
1172 		.channels_max = 2,
1173 		.rates = SNDRV_PCM_RATE_48000,
1174 		/* 16-bit capture is broken (errata ERR003778) */
1175 		.formats = SNDRV_PCM_FMTBIT_S20,
1176 	},
1177 	.ops = &fsl_ssi_dai_ops,
1178 };
1179 
1180 static struct fsl_ssi *fsl_ac97_data;
1181 
1182 static void fsl_ssi_ac97_write(struct snd_ac97 *ac97, unsigned short reg,
1183 			       unsigned short val)
1184 {
1185 	struct regmap *regs = fsl_ac97_data->regs;
1186 	unsigned int lreg;
1187 	unsigned int lval;
1188 	int ret;
1189 
1190 	if (reg > 0x7f)
1191 		return;
1192 
1193 	mutex_lock(&fsl_ac97_data->ac97_reg_lock);
1194 
1195 	ret = clk_prepare_enable(fsl_ac97_data->clk);
1196 	if (ret) {
1197 		pr_err("ac97 write clk_prepare_enable failed: %d\n",
1198 			ret);
1199 		goto ret_unlock;
1200 	}
1201 
1202 	lreg = reg <<  12;
1203 	regmap_write(regs, REG_SSI_SACADD, lreg);
1204 
1205 	lval = val << 4;
1206 	regmap_write(regs, REG_SSI_SACDAT, lval);
1207 
1208 	regmap_update_bits(regs, REG_SSI_SACNT,
1209 			   SSI_SACNT_RDWR_MASK, SSI_SACNT_WR);
1210 	udelay(100);
1211 
1212 	clk_disable_unprepare(fsl_ac97_data->clk);
1213 
1214 ret_unlock:
1215 	mutex_unlock(&fsl_ac97_data->ac97_reg_lock);
1216 }
1217 
1218 static unsigned short fsl_ssi_ac97_read(struct snd_ac97 *ac97,
1219 					unsigned short reg)
1220 {
1221 	struct regmap *regs = fsl_ac97_data->regs;
1222 	unsigned short val = 0;
1223 	u32 reg_val;
1224 	unsigned int lreg;
1225 	int ret;
1226 
1227 	mutex_lock(&fsl_ac97_data->ac97_reg_lock);
1228 
1229 	ret = clk_prepare_enable(fsl_ac97_data->clk);
1230 	if (ret) {
1231 		pr_err("ac97 read clk_prepare_enable failed: %d\n", ret);
1232 		goto ret_unlock;
1233 	}
1234 
1235 	lreg = (reg & 0x7f) <<  12;
1236 	regmap_write(regs, REG_SSI_SACADD, lreg);
1237 	regmap_update_bits(regs, REG_SSI_SACNT,
1238 			   SSI_SACNT_RDWR_MASK, SSI_SACNT_RD);
1239 
1240 	udelay(100);
1241 
1242 	regmap_read(regs, REG_SSI_SACDAT, &reg_val);
1243 	val = (reg_val >> 4) & 0xffff;
1244 
1245 	clk_disable_unprepare(fsl_ac97_data->clk);
1246 
1247 ret_unlock:
1248 	mutex_unlock(&fsl_ac97_data->ac97_reg_lock);
1249 	return val;
1250 }
1251 
1252 static struct snd_ac97_bus_ops fsl_ssi_ac97_ops = {
1253 	.read = fsl_ssi_ac97_read,
1254 	.write = fsl_ssi_ac97_write,
1255 };
1256 
1257 /**
1258  * fsl_ssi_hw_init - Initialize SSI registers
1259  * @ssi: SSI context
1260  */
1261 static int fsl_ssi_hw_init(struct fsl_ssi *ssi)
1262 {
1263 	u32 wm = ssi->fifo_watermark;
1264 
1265 	/* Initialize regvals */
1266 	fsl_ssi_setup_regvals(ssi);
1267 
1268 	/* Set watermarks */
1269 	regmap_write(ssi->regs, REG_SSI_SFCSR,
1270 		     SSI_SFCSR_TFWM0(wm) | SSI_SFCSR_RFWM0(wm) |
1271 		     SSI_SFCSR_TFWM1(wm) | SSI_SFCSR_RFWM1(wm));
1272 
1273 	/* Enable Dual FIFO mode */
1274 	if (ssi->use_dual_fifo)
1275 		regmap_update_bits(ssi->regs, REG_SSI_SCR,
1276 				   SSI_SCR_TCH_EN, SSI_SCR_TCH_EN);
1277 
1278 	/* AC97 should start earlier to communicate with CODECs */
1279 	if (fsl_ssi_is_ac97(ssi)) {
1280 		_fsl_ssi_set_dai_fmt(ssi, ssi->dai_fmt);
1281 		fsl_ssi_setup_ac97(ssi);
1282 	}
1283 
1284 	return 0;
1285 }
1286 
1287 /**
1288  * fsl_ssi_hw_clean - Clear SSI registers
1289  * @ssi: SSI context
1290  */
1291 static void fsl_ssi_hw_clean(struct fsl_ssi *ssi)
1292 {
1293 	/* Disable registers for AC97 */
1294 	if (fsl_ssi_is_ac97(ssi)) {
1295 		/* Disable TE and RE bits first */
1296 		regmap_update_bits(ssi->regs, REG_SSI_SCR,
1297 				   SSI_SCR_TE | SSI_SCR_RE, 0);
1298 		/* Disable AC97 mode */
1299 		regmap_write(ssi->regs, REG_SSI_SACNT, 0);
1300 		/* Unset WAIT bits */
1301 		regmap_write(ssi->regs, REG_SSI_SOR, 0);
1302 		/* Disable SSI -- software reset */
1303 		regmap_update_bits(ssi->regs, REG_SSI_SCR, SSI_SCR_SSIEN, 0);
1304 	}
1305 }
1306 
1307 /*
1308  * Make every character in a string lower-case
1309  */
1310 static void make_lowercase(char *s)
1311 {
1312 	if (!s)
1313 		return;
1314 	for (; *s; s++)
1315 		*s = tolower(*s);
1316 }
1317 
1318 static int fsl_ssi_imx_probe(struct platform_device *pdev,
1319 			     struct fsl_ssi *ssi, void __iomem *iomem)
1320 {
1321 	struct device *dev = &pdev->dev;
1322 	int ret;
1323 
1324 	/* Backward compatible for a DT without ipg clock name assigned */
1325 	if (ssi->has_ipg_clk_name)
1326 		ssi->clk = devm_clk_get(dev, "ipg");
1327 	else
1328 		ssi->clk = devm_clk_get(dev, NULL);
1329 	if (IS_ERR(ssi->clk)) {
1330 		ret = PTR_ERR(ssi->clk);
1331 		dev_err(dev, "failed to get clock: %d\n", ret);
1332 		return ret;
1333 	}
1334 
1335 	/* Enable the clock since regmap will not handle it in this case */
1336 	if (!ssi->has_ipg_clk_name) {
1337 		ret = clk_prepare_enable(ssi->clk);
1338 		if (ret) {
1339 			dev_err(dev, "clk_prepare_enable failed: %d\n", ret);
1340 			return ret;
1341 		}
1342 	}
1343 
1344 	/* Do not error out for slave cases that live without a baud clock */
1345 	ssi->baudclk = devm_clk_get(dev, "baud");
1346 	if (IS_ERR(ssi->baudclk))
1347 		dev_dbg(dev, "failed to get baud clock: %ld\n",
1348 			 PTR_ERR(ssi->baudclk));
1349 
1350 	ssi->dma_params_tx.maxburst = ssi->dma_maxburst;
1351 	ssi->dma_params_rx.maxburst = ssi->dma_maxburst;
1352 	ssi->dma_params_tx.addr = ssi->ssi_phys + REG_SSI_STX0;
1353 	ssi->dma_params_rx.addr = ssi->ssi_phys + REG_SSI_SRX0;
1354 
1355 	/* Use even numbers to avoid channel swap due to SDMA script design */
1356 	if (ssi->use_dual_fifo) {
1357 		ssi->dma_params_tx.maxburst &= ~0x1;
1358 		ssi->dma_params_rx.maxburst &= ~0x1;
1359 	}
1360 
1361 	if (!ssi->use_dma) {
1362 		/*
1363 		 * Some boards use an incompatible codec. Use imx-fiq-pcm-audio
1364 		 * to get it working, as DMA is not possible in this situation.
1365 		 */
1366 		ssi->fiq_params.irq = ssi->irq;
1367 		ssi->fiq_params.base = iomem;
1368 		ssi->fiq_params.dma_params_rx = &ssi->dma_params_rx;
1369 		ssi->fiq_params.dma_params_tx = &ssi->dma_params_tx;
1370 
1371 		ret = imx_pcm_fiq_init(pdev, &ssi->fiq_params);
1372 		if (ret)
1373 			goto error_pcm;
1374 	} else {
1375 		ret = imx_pcm_dma_init(pdev, IMX_SSI_DMABUF_SIZE);
1376 		if (ret)
1377 			goto error_pcm;
1378 	}
1379 
1380 	return 0;
1381 
1382 error_pcm:
1383 	if (!ssi->has_ipg_clk_name)
1384 		clk_disable_unprepare(ssi->clk);
1385 
1386 	return ret;
1387 }
1388 
1389 static void fsl_ssi_imx_clean(struct platform_device *pdev, struct fsl_ssi *ssi)
1390 {
1391 	if (!ssi->use_dma)
1392 		imx_pcm_fiq_exit(pdev);
1393 	if (!ssi->has_ipg_clk_name)
1394 		clk_disable_unprepare(ssi->clk);
1395 }
1396 
1397 static int fsl_ssi_probe_from_dt(struct fsl_ssi *ssi)
1398 {
1399 	struct device *dev = ssi->dev;
1400 	struct device_node *np = dev->of_node;
1401 	const char *p, *sprop;
1402 	const __be32 *iprop;
1403 	u32 dmas[4];
1404 	int ret;
1405 
1406 	ret = of_property_match_string(np, "clock-names", "ipg");
1407 	/* Get error code if not found */
1408 	ssi->has_ipg_clk_name = ret >= 0;
1409 
1410 	/* Check if being used in AC97 mode */
1411 	sprop = of_get_property(np, "fsl,mode", NULL);
1412 	if (sprop && !strcmp(sprop, "ac97-slave")) {
1413 		ssi->dai_fmt = FSLSSI_AC97_DAIFMT;
1414 
1415 		ret = of_property_read_u32(np, "cell-index", &ssi->card_idx);
1416 		if (ret) {
1417 			dev_err(dev, "failed to get SSI index property\n");
1418 			return -EINVAL;
1419 		}
1420 		strcpy(ssi->card_name, "ac97-codec");
1421 	} else if (!of_find_property(np, "fsl,ssi-asynchronous", NULL)) {
1422 		/*
1423 		 * In synchronous mode, STCK and STFS ports are used by RX
1424 		 * as well. So the software should limit the sample rates,
1425 		 * sample bits and channels to be symmetric.
1426 		 *
1427 		 * This is exclusive with FSLSSI_AC97_FORMATS as AC97 runs
1428 		 * in the SSI synchronous mode however it does not have to
1429 		 * limit symmetric sample rates and sample bits.
1430 		 */
1431 		ssi->synchronous = true;
1432 	}
1433 
1434 	/* Select DMA or FIQ */
1435 	ssi->use_dma = !of_property_read_bool(np, "fsl,fiq-stream-filter");
1436 
1437 	/* Fetch FIFO depth; Set to 8 for older DT without this property */
1438 	iprop = of_get_property(np, "fsl,fifo-depth", NULL);
1439 	if (iprop)
1440 		ssi->fifo_depth = be32_to_cpup(iprop);
1441 	else
1442 		ssi->fifo_depth = 8;
1443 
1444 	/* Use dual FIFO mode depending on the support from SDMA script */
1445 	ret = of_property_read_u32_array(np, "dmas", dmas, 4);
1446 	if (ssi->use_dma && !ret && dmas[2] == IMX_DMATYPE_SSI_DUAL)
1447 		ssi->use_dual_fifo = true;
1448 
1449 	/*
1450 	 * Backward compatible for older bindings by manually triggering the
1451 	 * machine driver's probe(). Use /compatible property, including the
1452 	 * address of CPU DAI driver structure, as the name of machine driver
1453 	 *
1454 	 * If card_name is set by AC97 earlier, bypass here since it uses a
1455 	 * different name to register the device.
1456 	 */
1457 	if (!ssi->card_name[0] && of_get_property(np, "codec-handle", NULL)) {
1458 		struct device_node *root = of_find_node_by_path("/");
1459 
1460 		sprop = of_get_property(root, "compatible", NULL);
1461 		of_node_put(root);
1462 		/* Strip "fsl," in the compatible name if applicable */
1463 		p = strrchr(sprop, ',');
1464 		if (p)
1465 			sprop = p + 1;
1466 		snprintf(ssi->card_name, sizeof(ssi->card_name),
1467 			 "snd-soc-%s", sprop);
1468 		make_lowercase(ssi->card_name);
1469 		ssi->card_idx = 0;
1470 	}
1471 
1472 	return 0;
1473 }
1474 
1475 static int fsl_ssi_probe(struct platform_device *pdev)
1476 {
1477 	struct regmap_config regconfig = fsl_ssi_regconfig;
1478 	struct device *dev = &pdev->dev;
1479 	struct fsl_ssi *ssi;
1480 	struct resource *res;
1481 	void __iomem *iomem;
1482 	int ret = 0;
1483 
1484 	ssi = devm_kzalloc(dev, sizeof(*ssi), GFP_KERNEL);
1485 	if (!ssi)
1486 		return -ENOMEM;
1487 
1488 	ssi->dev = dev;
1489 	ssi->soc = of_device_get_match_data(&pdev->dev);
1490 
1491 	/* Probe from DT */
1492 	ret = fsl_ssi_probe_from_dt(ssi);
1493 	if (ret)
1494 		return ret;
1495 
1496 	if (fsl_ssi_is_ac97(ssi)) {
1497 		memcpy(&ssi->cpu_dai_drv, &fsl_ssi_ac97_dai,
1498 		       sizeof(fsl_ssi_ac97_dai));
1499 		fsl_ac97_data = ssi;
1500 	} else {
1501 		memcpy(&ssi->cpu_dai_drv, &fsl_ssi_dai_template,
1502 		       sizeof(fsl_ssi_dai_template));
1503 	}
1504 	ssi->cpu_dai_drv.name = dev_name(dev);
1505 
1506 	iomem = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
1507 	if (IS_ERR(iomem))
1508 		return PTR_ERR(iomem);
1509 	ssi->ssi_phys = res->start;
1510 
1511 	if (ssi->soc->imx21regs) {
1512 		/* No SACC{ST,EN,DIS} regs in imx21-class SSI */
1513 		regconfig.max_register = REG_SSI_SRMSK;
1514 		regconfig.num_reg_defaults_raw =
1515 			REG_SSI_SRMSK / sizeof(uint32_t) + 1;
1516 	}
1517 
1518 	if (ssi->has_ipg_clk_name)
1519 		ssi->regs = devm_regmap_init_mmio_clk(dev, "ipg", iomem,
1520 						      &regconfig);
1521 	else
1522 		ssi->regs = devm_regmap_init_mmio(dev, iomem, &regconfig);
1523 	if (IS_ERR(ssi->regs)) {
1524 		dev_err(dev, "failed to init register map\n");
1525 		return PTR_ERR(ssi->regs);
1526 	}
1527 
1528 	ssi->irq = platform_get_irq(pdev, 0);
1529 	if (ssi->irq < 0)
1530 		return ssi->irq;
1531 
1532 	/* Set software limitations for synchronous mode except AC97 */
1533 	if (ssi->synchronous && !fsl_ssi_is_ac97(ssi)) {
1534 		ssi->cpu_dai_drv.symmetric_rate = 1;
1535 		ssi->cpu_dai_drv.symmetric_channels = 1;
1536 		ssi->cpu_dai_drv.symmetric_sample_bits = 1;
1537 	}
1538 
1539 	/*
1540 	 * Configure TX and RX DMA watermarks -- when to send a DMA request
1541 	 *
1542 	 * Values should be tested to avoid FIFO under/over run. Set maxburst
1543 	 * to fifo_watermark to maxiumize DMA transaction to reduce overhead.
1544 	 */
1545 	switch (ssi->fifo_depth) {
1546 	case 15:
1547 		/*
1548 		 * Set to 8 as a balanced configuration -- When TX FIFO has 8
1549 		 * empty slots, send a DMA request to fill these 8 slots. The
1550 		 * remaining 7 slots should be able to allow DMA to finish the
1551 		 * transaction before TX FIFO underruns; Same applies to RX.
1552 		 *
1553 		 * Tested with cases running at 48kHz @ 16 bits x 16 channels
1554 		 */
1555 		ssi->fifo_watermark = 8;
1556 		ssi->dma_maxburst = 8;
1557 		break;
1558 	case 8:
1559 	default:
1560 		/* Safely use old watermark configurations for older chips */
1561 		ssi->fifo_watermark = ssi->fifo_depth - 2;
1562 		ssi->dma_maxburst = ssi->fifo_depth - 2;
1563 		break;
1564 	}
1565 
1566 	dev_set_drvdata(dev, ssi);
1567 
1568 	if (ssi->soc->imx) {
1569 		ret = fsl_ssi_imx_probe(pdev, ssi, iomem);
1570 		if (ret)
1571 			return ret;
1572 	}
1573 
1574 	if (fsl_ssi_is_ac97(ssi)) {
1575 		mutex_init(&ssi->ac97_reg_lock);
1576 		ret = snd_soc_set_ac97_ops_of_reset(&fsl_ssi_ac97_ops, pdev);
1577 		if (ret) {
1578 			dev_err(dev, "failed to set AC'97 ops\n");
1579 			goto error_ac97_ops;
1580 		}
1581 	}
1582 
1583 	ret = devm_snd_soc_register_component(dev, &fsl_ssi_component,
1584 					      &ssi->cpu_dai_drv, 1);
1585 	if (ret) {
1586 		dev_err(dev, "failed to register DAI: %d\n", ret);
1587 		goto error_asoc_register;
1588 	}
1589 
1590 	if (ssi->use_dma) {
1591 		ret = devm_request_irq(dev, ssi->irq, fsl_ssi_isr, 0,
1592 				       dev_name(dev), ssi);
1593 		if (ret < 0) {
1594 			dev_err(dev, "failed to claim irq %u\n", ssi->irq);
1595 			goto error_asoc_register;
1596 		}
1597 	}
1598 
1599 	fsl_ssi_debugfs_create(&ssi->dbg_stats, dev);
1600 
1601 	/* Initially configures SSI registers */
1602 	fsl_ssi_hw_init(ssi);
1603 
1604 	/* Register a platform device for older bindings or AC97 */
1605 	if (ssi->card_name[0]) {
1606 		struct device *parent = dev;
1607 		/*
1608 		 * Do not set SSI dev as the parent of AC97 CODEC device since
1609 		 * it does not have a DT node. Otherwise ASoC core will assume
1610 		 * CODEC has the same DT node as the SSI, so it may bypass the
1611 		 * dai_probe() of SSI and then cause NULL DMA data pointers.
1612 		 */
1613 		if (fsl_ssi_is_ac97(ssi))
1614 			parent = NULL;
1615 
1616 		ssi->card_pdev = platform_device_register_data(parent,
1617 				ssi->card_name, ssi->card_idx, NULL, 0);
1618 		if (IS_ERR(ssi->card_pdev)) {
1619 			ret = PTR_ERR(ssi->card_pdev);
1620 			dev_err(dev, "failed to register %s: %d\n",
1621 				ssi->card_name, ret);
1622 			goto error_sound_card;
1623 		}
1624 	}
1625 
1626 	return 0;
1627 
1628 error_sound_card:
1629 	fsl_ssi_debugfs_remove(&ssi->dbg_stats);
1630 error_asoc_register:
1631 	if (fsl_ssi_is_ac97(ssi))
1632 		snd_soc_set_ac97_ops(NULL);
1633 error_ac97_ops:
1634 	if (fsl_ssi_is_ac97(ssi))
1635 		mutex_destroy(&ssi->ac97_reg_lock);
1636 
1637 	if (ssi->soc->imx)
1638 		fsl_ssi_imx_clean(pdev, ssi);
1639 
1640 	return ret;
1641 }
1642 
1643 static int fsl_ssi_remove(struct platform_device *pdev)
1644 {
1645 	struct fsl_ssi *ssi = dev_get_drvdata(&pdev->dev);
1646 
1647 	fsl_ssi_debugfs_remove(&ssi->dbg_stats);
1648 
1649 	if (ssi->card_pdev)
1650 		platform_device_unregister(ssi->card_pdev);
1651 
1652 	/* Clean up SSI registers */
1653 	fsl_ssi_hw_clean(ssi);
1654 
1655 	if (ssi->soc->imx)
1656 		fsl_ssi_imx_clean(pdev, ssi);
1657 
1658 	if (fsl_ssi_is_ac97(ssi)) {
1659 		snd_soc_set_ac97_ops(NULL);
1660 		mutex_destroy(&ssi->ac97_reg_lock);
1661 	}
1662 
1663 	return 0;
1664 }
1665 
1666 #ifdef CONFIG_PM_SLEEP
1667 static int fsl_ssi_suspend(struct device *dev)
1668 {
1669 	struct fsl_ssi *ssi = dev_get_drvdata(dev);
1670 	struct regmap *regs = ssi->regs;
1671 
1672 	regmap_read(regs, REG_SSI_SFCSR, &ssi->regcache_sfcsr);
1673 	regmap_read(regs, REG_SSI_SACNT, &ssi->regcache_sacnt);
1674 
1675 	regcache_cache_only(regs, true);
1676 	regcache_mark_dirty(regs);
1677 
1678 	return 0;
1679 }
1680 
1681 static int fsl_ssi_resume(struct device *dev)
1682 {
1683 	struct fsl_ssi *ssi = dev_get_drvdata(dev);
1684 	struct regmap *regs = ssi->regs;
1685 
1686 	regcache_cache_only(regs, false);
1687 
1688 	regmap_update_bits(regs, REG_SSI_SFCSR,
1689 			   SSI_SFCSR_RFWM1_MASK | SSI_SFCSR_TFWM1_MASK |
1690 			   SSI_SFCSR_RFWM0_MASK | SSI_SFCSR_TFWM0_MASK,
1691 			   ssi->regcache_sfcsr);
1692 	regmap_write(regs, REG_SSI_SACNT, ssi->regcache_sacnt);
1693 
1694 	return regcache_sync(regs);
1695 }
1696 #endif /* CONFIG_PM_SLEEP */
1697 
1698 static const struct dev_pm_ops fsl_ssi_pm = {
1699 	SET_SYSTEM_SLEEP_PM_OPS(fsl_ssi_suspend, fsl_ssi_resume)
1700 };
1701 
1702 static struct platform_driver fsl_ssi_driver = {
1703 	.driver = {
1704 		.name = "fsl-ssi-dai",
1705 		.of_match_table = fsl_ssi_ids,
1706 		.pm = &fsl_ssi_pm,
1707 	},
1708 	.probe = fsl_ssi_probe,
1709 	.remove = fsl_ssi_remove,
1710 };
1711 
1712 module_platform_driver(fsl_ssi_driver);
1713 
1714 MODULE_ALIAS("platform:fsl-ssi-dai");
1715 MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
1716 MODULE_DESCRIPTION("Freescale Synchronous Serial Interface (SSI) ASoC Driver");
1717 MODULE_LICENSE("GPL v2");
1718