xref: /linux/sound/soc/fsl/fsl_ssi.c (revision 3aed61d1eb06b8b19b7bb09d49b222ebc3f83347)
1 /*
2  * Freescale SSI ALSA SoC Digital Audio Interface (DAI) driver
3  *
4  * Author: Timur Tabi <timur@freescale.com>
5  *
6  * Copyright 2007-2010 Freescale Semiconductor, Inc.
7  *
8  * This file is licensed under the terms of the GNU General Public License
9  * version 2.  This program is licensed "as is" without any warranty of any
10  * kind, whether express or implied.
11  *
12  *
13  * Some notes why imx-pcm-fiq is used instead of DMA on some boards:
14  *
15  * The i.MX SSI core has some nasty limitations in AC97 mode. While most
16  * sane processor vendors have a FIFO per AC97 slot, the i.MX has only
17  * one FIFO which combines all valid receive slots. We cannot even select
18  * which slots we want to receive. The WM9712 with which this driver
19  * was developed with always sends GPIO status data in slot 12 which
20  * we receive in our (PCM-) data stream. The only chance we have is to
21  * manually skip this data in the FIQ handler. With sampling rates different
22  * from 48000Hz not every frame has valid receive data, so the ratio
23  * between pcm data and GPIO status data changes. Our FIQ handler is not
24  * able to handle this, hence this driver only works with 48000Hz sampling
25  * rate.
26  * Reading and writing AC97 registers is another challenge. The core
27  * provides us status bits when the read register is updated with *another*
28  * value. When we read the same register two times (and the register still
29  * contains the same value) these status bits are not set. We work
30  * around this by not polling these bits but only wait a fixed delay.
31  */
32 
33 #include <linux/init.h>
34 #include <linux/io.h>
35 #include <linux/module.h>
36 #include <linux/interrupt.h>
37 #include <linux/clk.h>
38 #include <linux/device.h>
39 #include <linux/delay.h>
40 #include <linux/slab.h>
41 #include <linux/spinlock.h>
42 #include <linux/of.h>
43 #include <linux/of_address.h>
44 #include <linux/of_irq.h>
45 #include <linux/of_platform.h>
46 
47 #include <sound/core.h>
48 #include <sound/pcm.h>
49 #include <sound/pcm_params.h>
50 #include <sound/initval.h>
51 #include <sound/soc.h>
52 #include <sound/dmaengine_pcm.h>
53 
54 #include "fsl_ssi.h"
55 #include "imx-pcm.h"
56 
57 /**
58  * FSLSSI_I2S_RATES: sample rates supported by the I2S
59  *
60  * This driver currently only supports the SSI running in I2S slave mode,
61  * which means the codec determines the sample rate.  Therefore, we tell
62  * ALSA that we support all rates and let the codec driver decide what rates
63  * are really supported.
64  */
65 #define FSLSSI_I2S_RATES SNDRV_PCM_RATE_CONTINUOUS
66 
67 /**
68  * FSLSSI_I2S_FORMATS: audio formats supported by the SSI
69  *
70  * The SSI has a limitation in that the samples must be in the same byte
71  * order as the host CPU.  This is because when multiple bytes are written
72  * to the STX register, the bytes and bits must be written in the same
73  * order.  The STX is a shift register, so all the bits need to be aligned
74  * (bit-endianness must match byte-endianness).  Processors typically write
75  * the bits within a byte in the same order that the bytes of a word are
76  * written in.  So if the host CPU is big-endian, then only big-endian
77  * samples will be written to STX properly.
78  */
79 #ifdef __BIG_ENDIAN
80 #define FSLSSI_I2S_FORMATS (SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_BE | \
81 	 SNDRV_PCM_FMTBIT_S18_3BE | SNDRV_PCM_FMTBIT_S20_3BE | \
82 	 SNDRV_PCM_FMTBIT_S24_3BE | SNDRV_PCM_FMTBIT_S24_BE)
83 #else
84 #define FSLSSI_I2S_FORMATS (SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_LE | \
85 	 SNDRV_PCM_FMTBIT_S18_3LE | SNDRV_PCM_FMTBIT_S20_3LE | \
86 	 SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_LE)
87 #endif
88 
89 #define FSLSSI_SIER_DBG_RX_FLAGS (CCSR_SSI_SIER_RFF0_EN | \
90 		CCSR_SSI_SIER_RLS_EN | CCSR_SSI_SIER_RFS_EN | \
91 		CCSR_SSI_SIER_ROE0_EN | CCSR_SSI_SIER_RFRC_EN)
92 #define FSLSSI_SIER_DBG_TX_FLAGS (CCSR_SSI_SIER_TFE0_EN | \
93 		CCSR_SSI_SIER_TLS_EN | CCSR_SSI_SIER_TFS_EN | \
94 		CCSR_SSI_SIER_TUE0_EN | CCSR_SSI_SIER_TFRC_EN)
95 
96 enum fsl_ssi_type {
97 	FSL_SSI_MCP8610,
98 	FSL_SSI_MX21,
99 	FSL_SSI_MX35,
100 	FSL_SSI_MX51,
101 };
102 
103 struct fsl_ssi_reg_val {
104 	u32 sier;
105 	u32 srcr;
106 	u32 stcr;
107 	u32 scr;
108 };
109 
110 struct fsl_ssi_rxtx_reg_val {
111 	struct fsl_ssi_reg_val rx;
112 	struct fsl_ssi_reg_val tx;
113 };
114 static const struct regmap_config fsl_ssi_regconfig = {
115 	.max_register = CCSR_SSI_SACCDIS,
116 	.reg_bits = 32,
117 	.val_bits = 32,
118 	.reg_stride = 4,
119 	.val_format_endian = REGMAP_ENDIAN_NATIVE,
120 };
121 
122 struct fsl_ssi_soc_data {
123 	bool imx;
124 	bool offline_config;
125 	u32 sisr_write_mask;
126 };
127 
128 /**
129  * fsl_ssi_private: per-SSI private data
130  *
131  * @reg: Pointer to the regmap registers
132  * @irq: IRQ of this SSI
133  * @cpu_dai_drv: CPU DAI driver for this device
134  *
135  * @dai_fmt: DAI configuration this device is currently used with
136  * @i2s_mode: i2s and network mode configuration of the device. Is used to
137  * switch between normal and i2s/network mode
138  * mode depending on the number of channels
139  * @use_dma: DMA is used or FIQ with stream filter
140  * @use_dual_fifo: DMA with support for both FIFOs used
141  * @fifo_deph: Depth of the SSI FIFOs
142  * @rxtx_reg_val: Specific register settings for receive/transmit configuration
143  *
144  * @clk: SSI clock
145  * @baudclk: SSI baud clock for master mode
146  * @baudclk_streams: Active streams that are using baudclk
147  * @bitclk_freq: bitclock frequency set by .set_dai_sysclk
148  *
149  * @dma_params_tx: DMA transmit parameters
150  * @dma_params_rx: DMA receive parameters
151  * @ssi_phys: physical address of the SSI registers
152  *
153  * @fiq_params: FIQ stream filtering parameters
154  *
155  * @pdev: Pointer to pdev used for deprecated fsl-ssi sound card
156  *
157  * @dbg_stats: Debugging statistics
158  *
159  * @soc: SoC specific data
160  */
161 struct fsl_ssi_private {
162 	struct regmap *regs;
163 	int irq;
164 	struct snd_soc_dai_driver cpu_dai_drv;
165 
166 	unsigned int dai_fmt;
167 	u8 i2s_mode;
168 	bool use_dma;
169 	bool use_dual_fifo;
170 	bool has_ipg_clk_name;
171 	unsigned int fifo_depth;
172 	struct fsl_ssi_rxtx_reg_val rxtx_reg_val;
173 
174 	struct clk *clk;
175 	struct clk *baudclk;
176 	unsigned int baudclk_streams;
177 	unsigned int bitclk_freq;
178 
179 	/* DMA params */
180 	struct snd_dmaengine_dai_dma_data dma_params_tx;
181 	struct snd_dmaengine_dai_dma_data dma_params_rx;
182 	dma_addr_t ssi_phys;
183 
184 	/* params for non-dma FIQ stream filtered mode */
185 	struct imx_pcm_fiq_params fiq_params;
186 
187 	/* Used when using fsl-ssi as sound-card. This is only used by ppc and
188 	 * should be replaced with simple-sound-card. */
189 	struct platform_device *pdev;
190 
191 	struct fsl_ssi_dbg dbg_stats;
192 
193 	const struct fsl_ssi_soc_data *soc;
194 };
195 
196 /*
197  * imx51 and later SoCs have a slightly different IP that allows the
198  * SSI configuration while the SSI unit is running.
199  *
200  * More important, it is necessary on those SoCs to configure the
201  * sperate TX/RX DMA bits just before starting the stream
202  * (fsl_ssi_trigger). The SDMA unit has to be configured before fsl_ssi
203  * sends any DMA requests to the SDMA unit, otherwise it is not defined
204  * how the SDMA unit handles the DMA request.
205  *
206  * SDMA units are present on devices starting at imx35 but the imx35
207  * reference manual states that the DMA bits should not be changed
208  * while the SSI unit is running (SSIEN). So we support the necessary
209  * online configuration of fsl-ssi starting at imx51.
210  */
211 
212 static struct fsl_ssi_soc_data fsl_ssi_mpc8610 = {
213 	.imx = false,
214 	.offline_config = true,
215 	.sisr_write_mask = CCSR_SSI_SISR_RFRC | CCSR_SSI_SISR_TFRC |
216 			CCSR_SSI_SISR_ROE0 | CCSR_SSI_SISR_ROE1 |
217 			CCSR_SSI_SISR_TUE0 | CCSR_SSI_SISR_TUE1,
218 };
219 
220 static struct fsl_ssi_soc_data fsl_ssi_imx21 = {
221 	.imx = true,
222 	.offline_config = true,
223 	.sisr_write_mask = 0,
224 };
225 
226 static struct fsl_ssi_soc_data fsl_ssi_imx35 = {
227 	.imx = true,
228 	.offline_config = true,
229 	.sisr_write_mask = CCSR_SSI_SISR_RFRC | CCSR_SSI_SISR_TFRC |
230 			CCSR_SSI_SISR_ROE0 | CCSR_SSI_SISR_ROE1 |
231 			CCSR_SSI_SISR_TUE0 | CCSR_SSI_SISR_TUE1,
232 };
233 
234 static struct fsl_ssi_soc_data fsl_ssi_imx51 = {
235 	.imx = true,
236 	.offline_config = false,
237 	.sisr_write_mask = CCSR_SSI_SISR_ROE0 | CCSR_SSI_SISR_ROE1 |
238 		CCSR_SSI_SISR_TUE0 | CCSR_SSI_SISR_TUE1,
239 };
240 
241 static const struct of_device_id fsl_ssi_ids[] = {
242 	{ .compatible = "fsl,mpc8610-ssi", .data = &fsl_ssi_mpc8610 },
243 	{ .compatible = "fsl,imx51-ssi", .data = &fsl_ssi_imx51 },
244 	{ .compatible = "fsl,imx35-ssi", .data = &fsl_ssi_imx35 },
245 	{ .compatible = "fsl,imx21-ssi", .data = &fsl_ssi_imx21 },
246 	{}
247 };
248 MODULE_DEVICE_TABLE(of, fsl_ssi_ids);
249 
250 static bool fsl_ssi_is_ac97(struct fsl_ssi_private *ssi_private)
251 {
252 	return !!(ssi_private->dai_fmt & SND_SOC_DAIFMT_AC97);
253 }
254 
255 static bool fsl_ssi_is_i2s_master(struct fsl_ssi_private *ssi_private)
256 {
257 	return (ssi_private->dai_fmt & SND_SOC_DAIFMT_MASTER_MASK) ==
258 		SND_SOC_DAIFMT_CBS_CFS;
259 }
260 
261 static bool fsl_ssi_is_i2s_cbm_cfs(struct fsl_ssi_private *ssi_private)
262 {
263 	return (ssi_private->dai_fmt & SND_SOC_DAIFMT_MASTER_MASK) ==
264 		SND_SOC_DAIFMT_CBM_CFS;
265 }
266 /**
267  * fsl_ssi_isr: SSI interrupt handler
268  *
269  * Although it's possible to use the interrupt handler to send and receive
270  * data to/from the SSI, we use the DMA instead.  Programming is more
271  * complicated, but the performance is much better.
272  *
273  * This interrupt handler is used only to gather statistics.
274  *
275  * @irq: IRQ of the SSI device
276  * @dev_id: pointer to the ssi_private structure for this SSI device
277  */
278 static irqreturn_t fsl_ssi_isr(int irq, void *dev_id)
279 {
280 	struct fsl_ssi_private *ssi_private = dev_id;
281 	struct regmap *regs = ssi_private->regs;
282 	__be32 sisr;
283 	__be32 sisr2;
284 
285 	/* We got an interrupt, so read the status register to see what we
286 	   were interrupted for.  We mask it with the Interrupt Enable register
287 	   so that we only check for events that we're interested in.
288 	 */
289 	regmap_read(regs, CCSR_SSI_SISR, &sisr);
290 
291 	sisr2 = sisr & ssi_private->soc->sisr_write_mask;
292 	/* Clear the bits that we set */
293 	if (sisr2)
294 		regmap_write(regs, CCSR_SSI_SISR, sisr2);
295 
296 	fsl_ssi_dbg_isr(&ssi_private->dbg_stats, sisr);
297 
298 	return IRQ_HANDLED;
299 }
300 
301 /*
302  * Enable/Disable all rx/tx config flags at once.
303  */
304 static void fsl_ssi_rxtx_config(struct fsl_ssi_private *ssi_private,
305 		bool enable)
306 {
307 	struct regmap *regs = ssi_private->regs;
308 	struct fsl_ssi_rxtx_reg_val *vals = &ssi_private->rxtx_reg_val;
309 
310 	if (enable) {
311 		regmap_update_bits(regs, CCSR_SSI_SIER,
312 				vals->rx.sier | vals->tx.sier,
313 				vals->rx.sier | vals->tx.sier);
314 		regmap_update_bits(regs, CCSR_SSI_SRCR,
315 				vals->rx.srcr | vals->tx.srcr,
316 				vals->rx.srcr | vals->tx.srcr);
317 		regmap_update_bits(regs, CCSR_SSI_STCR,
318 				vals->rx.stcr | vals->tx.stcr,
319 				vals->rx.stcr | vals->tx.stcr);
320 	} else {
321 		regmap_update_bits(regs, CCSR_SSI_SRCR,
322 				vals->rx.srcr | vals->tx.srcr, 0);
323 		regmap_update_bits(regs, CCSR_SSI_STCR,
324 				vals->rx.stcr | vals->tx.stcr, 0);
325 		regmap_update_bits(regs, CCSR_SSI_SIER,
326 				vals->rx.sier | vals->tx.sier, 0);
327 	}
328 }
329 
330 /*
331  * Calculate the bits that have to be disabled for the current stream that is
332  * getting disabled. This keeps the bits enabled that are necessary for the
333  * second stream to work if 'stream_active' is true.
334  *
335  * Detailed calculation:
336  * These are the values that need to be active after disabling. For non-active
337  * second stream, this is 0:
338  *	vals_stream * !!stream_active
339  *
340  * The following computes the overall differences between the setup for the
341  * to-disable stream and the active stream, a simple XOR:
342  *	vals_disable ^ (vals_stream * !!(stream_active))
343  *
344  * The full expression adds a mask on all values we care about
345  */
346 #define fsl_ssi_disable_val(vals_disable, vals_stream, stream_active) \
347 	((vals_disable) & \
348 	 ((vals_disable) ^ ((vals_stream) * (u32)!!(stream_active))))
349 
350 /*
351  * Enable/Disable a ssi configuration. You have to pass either
352  * ssi_private->rxtx_reg_val.rx or tx as vals parameter.
353  */
354 static void fsl_ssi_config(struct fsl_ssi_private *ssi_private, bool enable,
355 		struct fsl_ssi_reg_val *vals)
356 {
357 	struct regmap *regs = ssi_private->regs;
358 	struct fsl_ssi_reg_val *avals;
359 	int nr_active_streams;
360 	u32 scr_val;
361 	int keep_active;
362 
363 	regmap_read(regs, CCSR_SSI_SCR, &scr_val);
364 
365 	nr_active_streams = !!(scr_val & CCSR_SSI_SCR_TE) +
366 				!!(scr_val & CCSR_SSI_SCR_RE);
367 
368 	if (nr_active_streams - 1 > 0)
369 		keep_active = 1;
370 	else
371 		keep_active = 0;
372 
373 	/* Find the other direction values rx or tx which we do not want to
374 	 * modify */
375 	if (&ssi_private->rxtx_reg_val.rx == vals)
376 		avals = &ssi_private->rxtx_reg_val.tx;
377 	else
378 		avals = &ssi_private->rxtx_reg_val.rx;
379 
380 	/* If vals should be disabled, start with disabling the unit */
381 	if (!enable) {
382 		u32 scr = fsl_ssi_disable_val(vals->scr, avals->scr,
383 				keep_active);
384 		regmap_update_bits(regs, CCSR_SSI_SCR, scr, 0);
385 	}
386 
387 	/*
388 	 * We are running on a SoC which does not support online SSI
389 	 * reconfiguration, so we have to enable all necessary flags at once
390 	 * even if we do not use them later (capture and playback configuration)
391 	 */
392 	if (ssi_private->soc->offline_config) {
393 		if ((enable && !nr_active_streams) ||
394 				(!enable && !keep_active))
395 			fsl_ssi_rxtx_config(ssi_private, enable);
396 
397 		goto config_done;
398 	}
399 
400 	/*
401 	 * Configure single direction units while the SSI unit is running
402 	 * (online configuration)
403 	 */
404 	if (enable) {
405 		regmap_update_bits(regs, CCSR_SSI_SIER, vals->sier, vals->sier);
406 		regmap_update_bits(regs, CCSR_SSI_SRCR, vals->srcr, vals->srcr);
407 		regmap_update_bits(regs, CCSR_SSI_STCR, vals->stcr, vals->stcr);
408 	} else {
409 		u32 sier;
410 		u32 srcr;
411 		u32 stcr;
412 
413 		/*
414 		 * Disabling the necessary flags for one of rx/tx while the
415 		 * other stream is active is a little bit more difficult. We
416 		 * have to disable only those flags that differ between both
417 		 * streams (rx XOR tx) and that are set in the stream that is
418 		 * disabled now. Otherwise we could alter flags of the other
419 		 * stream
420 		 */
421 
422 		/* These assignments are simply vals without bits set in avals*/
423 		sier = fsl_ssi_disable_val(vals->sier, avals->sier,
424 				keep_active);
425 		srcr = fsl_ssi_disable_val(vals->srcr, avals->srcr,
426 				keep_active);
427 		stcr = fsl_ssi_disable_val(vals->stcr, avals->stcr,
428 				keep_active);
429 
430 		regmap_update_bits(regs, CCSR_SSI_SRCR, srcr, 0);
431 		regmap_update_bits(regs, CCSR_SSI_STCR, stcr, 0);
432 		regmap_update_bits(regs, CCSR_SSI_SIER, sier, 0);
433 	}
434 
435 config_done:
436 	/* Enabling of subunits is done after configuration */
437 	if (enable)
438 		regmap_update_bits(regs, CCSR_SSI_SCR, vals->scr, vals->scr);
439 }
440 
441 
442 static void fsl_ssi_rx_config(struct fsl_ssi_private *ssi_private, bool enable)
443 {
444 	fsl_ssi_config(ssi_private, enable, &ssi_private->rxtx_reg_val.rx);
445 }
446 
447 static void fsl_ssi_tx_config(struct fsl_ssi_private *ssi_private, bool enable)
448 {
449 	fsl_ssi_config(ssi_private, enable, &ssi_private->rxtx_reg_val.tx);
450 }
451 
452 /*
453  * Setup rx/tx register values used to enable/disable the streams. These will
454  * be used later in fsl_ssi_config to setup the streams without the need to
455  * check for all different SSI modes.
456  */
457 static void fsl_ssi_setup_reg_vals(struct fsl_ssi_private *ssi_private)
458 {
459 	struct fsl_ssi_rxtx_reg_val *reg = &ssi_private->rxtx_reg_val;
460 
461 	reg->rx.sier = CCSR_SSI_SIER_RFF0_EN;
462 	reg->rx.srcr = CCSR_SSI_SRCR_RFEN0;
463 	reg->rx.scr = 0;
464 	reg->tx.sier = CCSR_SSI_SIER_TFE0_EN;
465 	reg->tx.stcr = CCSR_SSI_STCR_TFEN0;
466 	reg->tx.scr = 0;
467 
468 	if (!fsl_ssi_is_ac97(ssi_private)) {
469 		reg->rx.scr = CCSR_SSI_SCR_SSIEN | CCSR_SSI_SCR_RE;
470 		reg->rx.sier |= CCSR_SSI_SIER_RFF0_EN;
471 		reg->tx.scr = CCSR_SSI_SCR_SSIEN | CCSR_SSI_SCR_TE;
472 		reg->tx.sier |= CCSR_SSI_SIER_TFE0_EN;
473 	}
474 
475 	if (ssi_private->use_dma) {
476 		reg->rx.sier |= CCSR_SSI_SIER_RDMAE;
477 		reg->tx.sier |= CCSR_SSI_SIER_TDMAE;
478 	} else {
479 		reg->rx.sier |= CCSR_SSI_SIER_RIE;
480 		reg->tx.sier |= CCSR_SSI_SIER_TIE;
481 	}
482 
483 	reg->rx.sier |= FSLSSI_SIER_DBG_RX_FLAGS;
484 	reg->tx.sier |= FSLSSI_SIER_DBG_TX_FLAGS;
485 }
486 
487 static void fsl_ssi_setup_ac97(struct fsl_ssi_private *ssi_private)
488 {
489 	struct regmap *regs = ssi_private->regs;
490 
491 	/*
492 	 * Setup the clock control register
493 	 */
494 	regmap_write(regs, CCSR_SSI_STCCR,
495 			CCSR_SSI_SxCCR_WL(17) | CCSR_SSI_SxCCR_DC(13));
496 	regmap_write(regs, CCSR_SSI_SRCCR,
497 			CCSR_SSI_SxCCR_WL(17) | CCSR_SSI_SxCCR_DC(13));
498 
499 	/*
500 	 * Enable AC97 mode and startup the SSI
501 	 */
502 	regmap_write(regs, CCSR_SSI_SACNT,
503 			CCSR_SSI_SACNT_AC97EN | CCSR_SSI_SACNT_FV);
504 	regmap_write(regs, CCSR_SSI_SACCDIS, 0xff);
505 	regmap_write(regs, CCSR_SSI_SACCEN, 0x300);
506 
507 	/*
508 	 * Enable SSI, Transmit and Receive. AC97 has to communicate with the
509 	 * codec before a stream is started.
510 	 */
511 	regmap_update_bits(regs, CCSR_SSI_SCR,
512 			CCSR_SSI_SCR_SSIEN | CCSR_SSI_SCR_TE | CCSR_SSI_SCR_RE,
513 			CCSR_SSI_SCR_SSIEN | CCSR_SSI_SCR_TE | CCSR_SSI_SCR_RE);
514 
515 	regmap_write(regs, CCSR_SSI_SOR, CCSR_SSI_SOR_WAIT(3));
516 }
517 
518 /**
519  * fsl_ssi_startup: create a new substream
520  *
521  * This is the first function called when a stream is opened.
522  *
523  * If this is the first stream open, then grab the IRQ and program most of
524  * the SSI registers.
525  */
526 static int fsl_ssi_startup(struct snd_pcm_substream *substream,
527 			   struct snd_soc_dai *dai)
528 {
529 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
530 	struct fsl_ssi_private *ssi_private =
531 		snd_soc_dai_get_drvdata(rtd->cpu_dai);
532 	int ret;
533 
534 	ret = clk_prepare_enable(ssi_private->clk);
535 	if (ret)
536 		return ret;
537 
538 	/* When using dual fifo mode, it is safer to ensure an even period
539 	 * size. If appearing to an odd number while DMA always starts its
540 	 * task from fifo0, fifo1 would be neglected at the end of each
541 	 * period. But SSI would still access fifo1 with an invalid data.
542 	 */
543 	if (ssi_private->use_dual_fifo)
544 		snd_pcm_hw_constraint_step(substream->runtime, 0,
545 				SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 2);
546 
547 	return 0;
548 }
549 
550 /**
551  * fsl_ssi_shutdown: shutdown the SSI
552  *
553  */
554 static void fsl_ssi_shutdown(struct snd_pcm_substream *substream,
555 				struct snd_soc_dai *dai)
556 {
557 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
558 	struct fsl_ssi_private *ssi_private =
559 		snd_soc_dai_get_drvdata(rtd->cpu_dai);
560 
561 	clk_disable_unprepare(ssi_private->clk);
562 
563 }
564 
565 /**
566  * fsl_ssi_set_bclk - configure Digital Audio Interface bit clock
567  *
568  * Note: This function can be only called when using SSI as DAI master
569  *
570  * Quick instruction for parameters:
571  * freq: Output BCLK frequency = samplerate * 32 (fixed) * channels
572  * dir: SND_SOC_CLOCK_OUT -> TxBCLK, SND_SOC_CLOCK_IN -> RxBCLK.
573  */
574 static int fsl_ssi_set_bclk(struct snd_pcm_substream *substream,
575 		struct snd_soc_dai *cpu_dai,
576 		struct snd_pcm_hw_params *hw_params)
577 {
578 	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(cpu_dai);
579 	struct regmap *regs = ssi_private->regs;
580 	int synchronous = ssi_private->cpu_dai_drv.symmetric_rates, ret;
581 	u32 pm = 999, div2, psr, stccr, mask, afreq, factor, i;
582 	unsigned long clkrate, baudrate, tmprate;
583 	u64 sub, savesub = 100000;
584 	unsigned int freq;
585 	bool baudclk_is_used;
586 
587 	/* Prefer the explicitly set bitclock frequency */
588 	if (ssi_private->bitclk_freq)
589 		freq = ssi_private->bitclk_freq;
590 	else
591 		freq = params_channels(hw_params) * 32 * params_rate(hw_params);
592 
593 	/* Don't apply it to any non-baudclk circumstance */
594 	if (IS_ERR(ssi_private->baudclk))
595 		return -EINVAL;
596 
597 	baudclk_is_used = ssi_private->baudclk_streams & ~(BIT(substream->stream));
598 
599 	/* It should be already enough to divide clock by setting pm alone */
600 	psr = 0;
601 	div2 = 0;
602 
603 	factor = (div2 + 1) * (7 * psr + 1) * 2;
604 
605 	for (i = 0; i < 255; i++) {
606 		tmprate = freq * factor * (i + 1);
607 
608 		if (baudclk_is_used)
609 			clkrate = clk_get_rate(ssi_private->baudclk);
610 		else
611 			clkrate = clk_round_rate(ssi_private->baudclk, tmprate);
612 
613 		/*
614 		 * Hardware limitation: The bclk rate must be
615 		 * never greater than 1/5 IPG clock rate
616 		 */
617 		if (clkrate * 5 > clk_get_rate(ssi_private->clk))
618 			continue;
619 
620 		clkrate /= factor;
621 		afreq = clkrate / (i + 1);
622 
623 		if (freq == afreq)
624 			sub = 0;
625 		else if (freq / afreq == 1)
626 			sub = freq - afreq;
627 		else if (afreq / freq == 1)
628 			sub = afreq - freq;
629 		else
630 			continue;
631 
632 		/* Calculate the fraction */
633 		sub *= 100000;
634 		do_div(sub, freq);
635 
636 		if (sub < savesub && !(i == 0 && psr == 0 && div2 == 0)) {
637 			baudrate = tmprate;
638 			savesub = sub;
639 			pm = i;
640 		}
641 
642 		/* We are lucky */
643 		if (savesub == 0)
644 			break;
645 	}
646 
647 	/* No proper pm found if it is still remaining the initial value */
648 	if (pm == 999) {
649 		dev_err(cpu_dai->dev, "failed to handle the required sysclk\n");
650 		return -EINVAL;
651 	}
652 
653 	stccr = CCSR_SSI_SxCCR_PM(pm + 1) | (div2 ? CCSR_SSI_SxCCR_DIV2 : 0) |
654 		(psr ? CCSR_SSI_SxCCR_PSR : 0);
655 	mask = CCSR_SSI_SxCCR_PM_MASK | CCSR_SSI_SxCCR_DIV2 |
656 		CCSR_SSI_SxCCR_PSR;
657 
658 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK || synchronous)
659 		regmap_update_bits(regs, CCSR_SSI_STCCR, mask, stccr);
660 	else
661 		regmap_update_bits(regs, CCSR_SSI_SRCCR, mask, stccr);
662 
663 	if (!baudclk_is_used) {
664 		ret = clk_set_rate(ssi_private->baudclk, baudrate);
665 		if (ret) {
666 			dev_err(cpu_dai->dev, "failed to set baudclk rate\n");
667 			return -EINVAL;
668 		}
669 	}
670 
671 	return 0;
672 }
673 
674 static int fsl_ssi_set_dai_sysclk(struct snd_soc_dai *cpu_dai,
675 		int clk_id, unsigned int freq, int dir)
676 {
677 	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(cpu_dai);
678 
679 	ssi_private->bitclk_freq = freq;
680 
681 	return 0;
682 }
683 
684 /**
685  * fsl_ssi_hw_params - program the sample size
686  *
687  * Most of the SSI registers have been programmed in the startup function,
688  * but the word length must be programmed here.  Unfortunately, programming
689  * the SxCCR.WL bits requires the SSI to be temporarily disabled.  This can
690  * cause a problem with supporting simultaneous playback and capture.  If
691  * the SSI is already playing a stream, then that stream may be temporarily
692  * stopped when you start capture.
693  *
694  * Note: The SxCCR.DC and SxCCR.PM bits are only used if the SSI is the
695  * clock master.
696  */
697 static int fsl_ssi_hw_params(struct snd_pcm_substream *substream,
698 	struct snd_pcm_hw_params *hw_params, struct snd_soc_dai *cpu_dai)
699 {
700 	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(cpu_dai);
701 	struct regmap *regs = ssi_private->regs;
702 	unsigned int channels = params_channels(hw_params);
703 	unsigned int sample_size =
704 		snd_pcm_format_width(params_format(hw_params));
705 	u32 wl = CCSR_SSI_SxCCR_WL(sample_size);
706 	int ret;
707 	u32 scr_val;
708 	int enabled;
709 
710 	regmap_read(regs, CCSR_SSI_SCR, &scr_val);
711 	enabled = scr_val & CCSR_SSI_SCR_SSIEN;
712 
713 	/*
714 	 * If we're in synchronous mode, and the SSI is already enabled,
715 	 * then STCCR is already set properly.
716 	 */
717 	if (enabled && ssi_private->cpu_dai_drv.symmetric_rates)
718 		return 0;
719 
720 	if (fsl_ssi_is_i2s_master(ssi_private)) {
721 		ret = fsl_ssi_set_bclk(substream, cpu_dai, hw_params);
722 		if (ret)
723 			return ret;
724 
725 		/* Do not enable the clock if it is already enabled */
726 		if (!(ssi_private->baudclk_streams & BIT(substream->stream))) {
727 			ret = clk_prepare_enable(ssi_private->baudclk);
728 			if (ret)
729 				return ret;
730 
731 			ssi_private->baudclk_streams |= BIT(substream->stream);
732 		}
733 	}
734 
735 	if (!fsl_ssi_is_ac97(ssi_private)) {
736 		u8 i2smode;
737 		/*
738 		 * Switch to normal net mode in order to have a frame sync
739 		 * signal every 32 bits instead of 16 bits
740 		 */
741 		if (fsl_ssi_is_i2s_cbm_cfs(ssi_private) && sample_size == 16)
742 			i2smode = CCSR_SSI_SCR_I2S_MODE_NORMAL |
743 				CCSR_SSI_SCR_NET;
744 		else
745 			i2smode = ssi_private->i2s_mode;
746 
747 		regmap_update_bits(regs, CCSR_SSI_SCR,
748 				CCSR_SSI_SCR_NET | CCSR_SSI_SCR_I2S_MODE_MASK,
749 				channels == 1 ? 0 : i2smode);
750 	}
751 
752 	/*
753 	 * FIXME: The documentation says that SxCCR[WL] should not be
754 	 * modified while the SSI is enabled.  The only time this can
755 	 * happen is if we're trying to do simultaneous playback and
756 	 * capture in asynchronous mode.  Unfortunately, I have been enable
757 	 * to get that to work at all on the P1022DS.  Therefore, we don't
758 	 * bother to disable/enable the SSI when setting SxCCR[WL], because
759 	 * the SSI will stop anyway.  Maybe one day, this will get fixed.
760 	 */
761 
762 	/* In synchronous mode, the SSI uses STCCR for capture */
763 	if ((substream->stream == SNDRV_PCM_STREAM_PLAYBACK) ||
764 	    ssi_private->cpu_dai_drv.symmetric_rates)
765 		regmap_update_bits(regs, CCSR_SSI_STCCR, CCSR_SSI_SxCCR_WL_MASK,
766 				wl);
767 	else
768 		regmap_update_bits(regs, CCSR_SSI_SRCCR, CCSR_SSI_SxCCR_WL_MASK,
769 				wl);
770 
771 	return 0;
772 }
773 
774 static int fsl_ssi_hw_free(struct snd_pcm_substream *substream,
775 		struct snd_soc_dai *cpu_dai)
776 {
777 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
778 	struct fsl_ssi_private *ssi_private =
779 		snd_soc_dai_get_drvdata(rtd->cpu_dai);
780 
781 	if (fsl_ssi_is_i2s_master(ssi_private) &&
782 			ssi_private->baudclk_streams & BIT(substream->stream)) {
783 		clk_disable_unprepare(ssi_private->baudclk);
784 		ssi_private->baudclk_streams &= ~BIT(substream->stream);
785 	}
786 
787 	return 0;
788 }
789 
790 static int _fsl_ssi_set_dai_fmt(struct device *dev,
791 				struct fsl_ssi_private *ssi_private,
792 				unsigned int fmt)
793 {
794 	struct regmap *regs = ssi_private->regs;
795 	u32 strcr = 0, stcr, srcr, scr, mask;
796 	u8 wm;
797 
798 	ssi_private->dai_fmt = fmt;
799 
800 	if (fsl_ssi_is_i2s_master(ssi_private) && IS_ERR(ssi_private->baudclk)) {
801 		dev_err(dev, "baudclk is missing which is necessary for master mode\n");
802 		return -EINVAL;
803 	}
804 
805 	fsl_ssi_setup_reg_vals(ssi_private);
806 
807 	regmap_read(regs, CCSR_SSI_SCR, &scr);
808 	scr &= ~(CCSR_SSI_SCR_SYN | CCSR_SSI_SCR_I2S_MODE_MASK);
809 	scr |= CCSR_SSI_SCR_SYNC_TX_FS;
810 
811 	mask = CCSR_SSI_STCR_TXBIT0 | CCSR_SSI_STCR_TFDIR | CCSR_SSI_STCR_TXDIR |
812 		CCSR_SSI_STCR_TSCKP | CCSR_SSI_STCR_TFSI | CCSR_SSI_STCR_TFSL |
813 		CCSR_SSI_STCR_TEFS;
814 	regmap_read(regs, CCSR_SSI_STCR, &stcr);
815 	regmap_read(regs, CCSR_SSI_SRCR, &srcr);
816 	stcr &= ~mask;
817 	srcr &= ~mask;
818 
819 	ssi_private->i2s_mode = CCSR_SSI_SCR_NET;
820 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
821 	case SND_SOC_DAIFMT_I2S:
822 		switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
823 		case SND_SOC_DAIFMT_CBM_CFS:
824 		case SND_SOC_DAIFMT_CBS_CFS:
825 			ssi_private->i2s_mode |= CCSR_SSI_SCR_I2S_MODE_MASTER;
826 			regmap_update_bits(regs, CCSR_SSI_STCCR,
827 					CCSR_SSI_SxCCR_DC_MASK,
828 					CCSR_SSI_SxCCR_DC(2));
829 			regmap_update_bits(regs, CCSR_SSI_SRCCR,
830 					CCSR_SSI_SxCCR_DC_MASK,
831 					CCSR_SSI_SxCCR_DC(2));
832 			break;
833 		case SND_SOC_DAIFMT_CBM_CFM:
834 			ssi_private->i2s_mode |= CCSR_SSI_SCR_I2S_MODE_SLAVE;
835 			break;
836 		default:
837 			return -EINVAL;
838 		}
839 
840 		/* Data on rising edge of bclk, frame low, 1clk before data */
841 		strcr |= CCSR_SSI_STCR_TFSI | CCSR_SSI_STCR_TSCKP |
842 			CCSR_SSI_STCR_TXBIT0 | CCSR_SSI_STCR_TEFS;
843 		break;
844 	case SND_SOC_DAIFMT_LEFT_J:
845 		/* Data on rising edge of bclk, frame high */
846 		strcr |= CCSR_SSI_STCR_TXBIT0 | CCSR_SSI_STCR_TSCKP;
847 		break;
848 	case SND_SOC_DAIFMT_DSP_A:
849 		/* Data on rising edge of bclk, frame high, 1clk before data */
850 		strcr |= CCSR_SSI_STCR_TFSL | CCSR_SSI_STCR_TSCKP |
851 			CCSR_SSI_STCR_TXBIT0 | CCSR_SSI_STCR_TEFS;
852 		break;
853 	case SND_SOC_DAIFMT_DSP_B:
854 		/* Data on rising edge of bclk, frame high */
855 		strcr |= CCSR_SSI_STCR_TFSL | CCSR_SSI_STCR_TSCKP |
856 			CCSR_SSI_STCR_TXBIT0;
857 		break;
858 	case SND_SOC_DAIFMT_AC97:
859 		ssi_private->i2s_mode |= CCSR_SSI_SCR_I2S_MODE_NORMAL;
860 		break;
861 	default:
862 		return -EINVAL;
863 	}
864 	scr |= ssi_private->i2s_mode;
865 
866 	/* DAI clock inversion */
867 	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
868 	case SND_SOC_DAIFMT_NB_NF:
869 		/* Nothing to do for both normal cases */
870 		break;
871 	case SND_SOC_DAIFMT_IB_NF:
872 		/* Invert bit clock */
873 		strcr ^= CCSR_SSI_STCR_TSCKP;
874 		break;
875 	case SND_SOC_DAIFMT_NB_IF:
876 		/* Invert frame clock */
877 		strcr ^= CCSR_SSI_STCR_TFSI;
878 		break;
879 	case SND_SOC_DAIFMT_IB_IF:
880 		/* Invert both clocks */
881 		strcr ^= CCSR_SSI_STCR_TSCKP;
882 		strcr ^= CCSR_SSI_STCR_TFSI;
883 		break;
884 	default:
885 		return -EINVAL;
886 	}
887 
888 	/* DAI clock master masks */
889 	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
890 	case SND_SOC_DAIFMT_CBS_CFS:
891 		strcr |= CCSR_SSI_STCR_TFDIR | CCSR_SSI_STCR_TXDIR;
892 		scr |= CCSR_SSI_SCR_SYS_CLK_EN;
893 		break;
894 	case SND_SOC_DAIFMT_CBM_CFM:
895 		scr &= ~CCSR_SSI_SCR_SYS_CLK_EN;
896 		break;
897 	case SND_SOC_DAIFMT_CBM_CFS:
898 		strcr &= ~CCSR_SSI_STCR_TXDIR;
899 		strcr |= CCSR_SSI_STCR_TFDIR;
900 		scr &= ~CCSR_SSI_SCR_SYS_CLK_EN;
901 		break;
902 	default:
903 		if (!fsl_ssi_is_ac97(ssi_private))
904 			return -EINVAL;
905 	}
906 
907 	stcr |= strcr;
908 	srcr |= strcr;
909 
910 	if (ssi_private->cpu_dai_drv.symmetric_rates
911 			|| fsl_ssi_is_ac97(ssi_private)) {
912 		/* Need to clear RXDIR when using SYNC or AC97 mode */
913 		srcr &= ~CCSR_SSI_SRCR_RXDIR;
914 		scr |= CCSR_SSI_SCR_SYN;
915 	}
916 
917 	regmap_write(regs, CCSR_SSI_STCR, stcr);
918 	regmap_write(regs, CCSR_SSI_SRCR, srcr);
919 	regmap_write(regs, CCSR_SSI_SCR, scr);
920 
921 	/*
922 	 * Set the watermark for transmit FIFI 0 and receive FIFO 0. We don't
923 	 * use FIFO 1. We program the transmit water to signal a DMA transfer
924 	 * if there are only two (or fewer) elements left in the FIFO. Two
925 	 * elements equals one frame (left channel, right channel). This value,
926 	 * however, depends on the depth of the transmit buffer.
927 	 *
928 	 * We set the watermark on the same level as the DMA burstsize.  For
929 	 * fiq it is probably better to use the biggest possible watermark
930 	 * size.
931 	 */
932 	if (ssi_private->use_dma)
933 		wm = ssi_private->fifo_depth - 2;
934 	else
935 		wm = ssi_private->fifo_depth;
936 
937 	regmap_write(regs, CCSR_SSI_SFCSR,
938 			CCSR_SSI_SFCSR_TFWM0(wm) | CCSR_SSI_SFCSR_RFWM0(wm) |
939 			CCSR_SSI_SFCSR_TFWM1(wm) | CCSR_SSI_SFCSR_RFWM1(wm));
940 
941 	if (ssi_private->use_dual_fifo) {
942 		regmap_update_bits(regs, CCSR_SSI_SRCR, CCSR_SSI_SRCR_RFEN1,
943 				CCSR_SSI_SRCR_RFEN1);
944 		regmap_update_bits(regs, CCSR_SSI_STCR, CCSR_SSI_STCR_TFEN1,
945 				CCSR_SSI_STCR_TFEN1);
946 		regmap_update_bits(regs, CCSR_SSI_SCR, CCSR_SSI_SCR_TCH_EN,
947 				CCSR_SSI_SCR_TCH_EN);
948 	}
949 
950 	if (fmt & SND_SOC_DAIFMT_AC97)
951 		fsl_ssi_setup_ac97(ssi_private);
952 
953 	return 0;
954 
955 }
956 
957 /**
958  * fsl_ssi_set_dai_fmt - configure Digital Audio Interface Format.
959  */
960 static int fsl_ssi_set_dai_fmt(struct snd_soc_dai *cpu_dai, unsigned int fmt)
961 {
962 	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(cpu_dai);
963 
964 	return _fsl_ssi_set_dai_fmt(cpu_dai->dev, ssi_private, fmt);
965 }
966 
967 /**
968  * fsl_ssi_set_dai_tdm_slot - set TDM slot number
969  *
970  * Note: This function can be only called when using SSI as DAI master
971  */
972 static int fsl_ssi_set_dai_tdm_slot(struct snd_soc_dai *cpu_dai, u32 tx_mask,
973 				u32 rx_mask, int slots, int slot_width)
974 {
975 	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(cpu_dai);
976 	struct regmap *regs = ssi_private->regs;
977 	u32 val;
978 
979 	/* The slot number should be >= 2 if using Network mode or I2S mode */
980 	regmap_read(regs, CCSR_SSI_SCR, &val);
981 	val &= CCSR_SSI_SCR_I2S_MODE_MASK | CCSR_SSI_SCR_NET;
982 	if (val && slots < 2) {
983 		dev_err(cpu_dai->dev, "slot number should be >= 2 in I2S or NET\n");
984 		return -EINVAL;
985 	}
986 
987 	regmap_update_bits(regs, CCSR_SSI_STCCR, CCSR_SSI_SxCCR_DC_MASK,
988 			CCSR_SSI_SxCCR_DC(slots));
989 	regmap_update_bits(regs, CCSR_SSI_SRCCR, CCSR_SSI_SxCCR_DC_MASK,
990 			CCSR_SSI_SxCCR_DC(slots));
991 
992 	/* The register SxMSKs needs SSI to provide essential clock due to
993 	 * hardware design. So we here temporarily enable SSI to set them.
994 	 */
995 	regmap_read(regs, CCSR_SSI_SCR, &val);
996 	val &= CCSR_SSI_SCR_SSIEN;
997 	regmap_update_bits(regs, CCSR_SSI_SCR, CCSR_SSI_SCR_SSIEN,
998 			CCSR_SSI_SCR_SSIEN);
999 
1000 	regmap_write(regs, CCSR_SSI_STMSK, ~tx_mask);
1001 	regmap_write(regs, CCSR_SSI_SRMSK, ~rx_mask);
1002 
1003 	regmap_update_bits(regs, CCSR_SSI_SCR, CCSR_SSI_SCR_SSIEN, val);
1004 
1005 	return 0;
1006 }
1007 
1008 /**
1009  * fsl_ssi_trigger: start and stop the DMA transfer.
1010  *
1011  * This function is called by ALSA to start, stop, pause, and resume the DMA
1012  * transfer of data.
1013  *
1014  * The DMA channel is in external master start and pause mode, which
1015  * means the SSI completely controls the flow of data.
1016  */
1017 static int fsl_ssi_trigger(struct snd_pcm_substream *substream, int cmd,
1018 			   struct snd_soc_dai *dai)
1019 {
1020 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
1021 	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(rtd->cpu_dai);
1022 	struct regmap *regs = ssi_private->regs;
1023 
1024 	switch (cmd) {
1025 	case SNDRV_PCM_TRIGGER_START:
1026 	case SNDRV_PCM_TRIGGER_RESUME:
1027 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1028 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
1029 			fsl_ssi_tx_config(ssi_private, true);
1030 		else
1031 			fsl_ssi_rx_config(ssi_private, true);
1032 		break;
1033 
1034 	case SNDRV_PCM_TRIGGER_STOP:
1035 	case SNDRV_PCM_TRIGGER_SUSPEND:
1036 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1037 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
1038 			fsl_ssi_tx_config(ssi_private, false);
1039 		else
1040 			fsl_ssi_rx_config(ssi_private, false);
1041 		break;
1042 
1043 	default:
1044 		return -EINVAL;
1045 	}
1046 
1047 	if (fsl_ssi_is_ac97(ssi_private)) {
1048 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
1049 			regmap_write(regs, CCSR_SSI_SOR, CCSR_SSI_SOR_TX_CLR);
1050 		else
1051 			regmap_write(regs, CCSR_SSI_SOR, CCSR_SSI_SOR_RX_CLR);
1052 	}
1053 
1054 	return 0;
1055 }
1056 
1057 static int fsl_ssi_dai_probe(struct snd_soc_dai *dai)
1058 {
1059 	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(dai);
1060 
1061 	if (ssi_private->soc->imx && ssi_private->use_dma) {
1062 		dai->playback_dma_data = &ssi_private->dma_params_tx;
1063 		dai->capture_dma_data = &ssi_private->dma_params_rx;
1064 	}
1065 
1066 	return 0;
1067 }
1068 
1069 static const struct snd_soc_dai_ops fsl_ssi_dai_ops = {
1070 	.startup	= fsl_ssi_startup,
1071 	.shutdown       = fsl_ssi_shutdown,
1072 	.hw_params	= fsl_ssi_hw_params,
1073 	.hw_free	= fsl_ssi_hw_free,
1074 	.set_fmt	= fsl_ssi_set_dai_fmt,
1075 	.set_sysclk	= fsl_ssi_set_dai_sysclk,
1076 	.set_tdm_slot	= fsl_ssi_set_dai_tdm_slot,
1077 	.trigger	= fsl_ssi_trigger,
1078 };
1079 
1080 /* Template for the CPU dai driver structure */
1081 static struct snd_soc_dai_driver fsl_ssi_dai_template = {
1082 	.probe = fsl_ssi_dai_probe,
1083 	.playback = {
1084 		.stream_name = "CPU-Playback",
1085 		.channels_min = 1,
1086 		.channels_max = 2,
1087 		.rates = FSLSSI_I2S_RATES,
1088 		.formats = FSLSSI_I2S_FORMATS,
1089 	},
1090 	.capture = {
1091 		.stream_name = "CPU-Capture",
1092 		.channels_min = 1,
1093 		.channels_max = 2,
1094 		.rates = FSLSSI_I2S_RATES,
1095 		.formats = FSLSSI_I2S_FORMATS,
1096 	},
1097 	.ops = &fsl_ssi_dai_ops,
1098 };
1099 
1100 static const struct snd_soc_component_driver fsl_ssi_component = {
1101 	.name		= "fsl-ssi",
1102 };
1103 
1104 static struct snd_soc_dai_driver fsl_ssi_ac97_dai = {
1105 	.bus_control = true,
1106 	.probe = fsl_ssi_dai_probe,
1107 	.playback = {
1108 		.stream_name = "AC97 Playback",
1109 		.channels_min = 2,
1110 		.channels_max = 2,
1111 		.rates = SNDRV_PCM_RATE_8000_48000,
1112 		.formats = SNDRV_PCM_FMTBIT_S16_LE,
1113 	},
1114 	.capture = {
1115 		.stream_name = "AC97 Capture",
1116 		.channels_min = 2,
1117 		.channels_max = 2,
1118 		.rates = SNDRV_PCM_RATE_48000,
1119 		.formats = SNDRV_PCM_FMTBIT_S16_LE,
1120 	},
1121 	.ops = &fsl_ssi_dai_ops,
1122 };
1123 
1124 
1125 static struct fsl_ssi_private *fsl_ac97_data;
1126 
1127 static void fsl_ssi_ac97_write(struct snd_ac97 *ac97, unsigned short reg,
1128 		unsigned short val)
1129 {
1130 	struct regmap *regs = fsl_ac97_data->regs;
1131 	unsigned int lreg;
1132 	unsigned int lval;
1133 	int ret;
1134 
1135 	if (reg > 0x7f)
1136 		return;
1137 
1138 	ret = clk_prepare_enable(fsl_ac97_data->clk);
1139 	if (ret) {
1140 		pr_err("ac97 write clk_prepare_enable failed: %d\n",
1141 			ret);
1142 		return;
1143 	}
1144 
1145 	lreg = reg <<  12;
1146 	regmap_write(regs, CCSR_SSI_SACADD, lreg);
1147 
1148 	lval = val << 4;
1149 	regmap_write(regs, CCSR_SSI_SACDAT, lval);
1150 
1151 	regmap_update_bits(regs, CCSR_SSI_SACNT, CCSR_SSI_SACNT_RDWR_MASK,
1152 			CCSR_SSI_SACNT_WR);
1153 	udelay(100);
1154 
1155 	clk_disable_unprepare(fsl_ac97_data->clk);
1156 }
1157 
1158 static unsigned short fsl_ssi_ac97_read(struct snd_ac97 *ac97,
1159 		unsigned short reg)
1160 {
1161 	struct regmap *regs = fsl_ac97_data->regs;
1162 
1163 	unsigned short val = -1;
1164 	u32 reg_val;
1165 	unsigned int lreg;
1166 	int ret;
1167 
1168 	ret = clk_prepare_enable(fsl_ac97_data->clk);
1169 	if (ret) {
1170 		pr_err("ac97 read clk_prepare_enable failed: %d\n",
1171 			ret);
1172 		return -1;
1173 	}
1174 
1175 	lreg = (reg & 0x7f) <<  12;
1176 	regmap_write(regs, CCSR_SSI_SACADD, lreg);
1177 	regmap_update_bits(regs, CCSR_SSI_SACNT, CCSR_SSI_SACNT_RDWR_MASK,
1178 			CCSR_SSI_SACNT_RD);
1179 
1180 	udelay(100);
1181 
1182 	regmap_read(regs, CCSR_SSI_SACDAT, &reg_val);
1183 	val = (reg_val >> 4) & 0xffff;
1184 
1185 	clk_disable_unprepare(fsl_ac97_data->clk);
1186 
1187 	return val;
1188 }
1189 
1190 static struct snd_ac97_bus_ops fsl_ssi_ac97_ops = {
1191 	.read		= fsl_ssi_ac97_read,
1192 	.write		= fsl_ssi_ac97_write,
1193 };
1194 
1195 /**
1196  * Make every character in a string lower-case
1197  */
1198 static void make_lowercase(char *s)
1199 {
1200 	char *p = s;
1201 	char c;
1202 
1203 	while ((c = *p)) {
1204 		if ((c >= 'A') && (c <= 'Z'))
1205 			*p = c + ('a' - 'A');
1206 		p++;
1207 	}
1208 }
1209 
1210 static int fsl_ssi_imx_probe(struct platform_device *pdev,
1211 		struct fsl_ssi_private *ssi_private, void __iomem *iomem)
1212 {
1213 	struct device_node *np = pdev->dev.of_node;
1214 	u32 dmas[4];
1215 	int ret;
1216 
1217 	if (ssi_private->has_ipg_clk_name)
1218 		ssi_private->clk = devm_clk_get(&pdev->dev, "ipg");
1219 	else
1220 		ssi_private->clk = devm_clk_get(&pdev->dev, NULL);
1221 	if (IS_ERR(ssi_private->clk)) {
1222 		ret = PTR_ERR(ssi_private->clk);
1223 		dev_err(&pdev->dev, "could not get clock: %d\n", ret);
1224 		return ret;
1225 	}
1226 
1227 	if (!ssi_private->has_ipg_clk_name) {
1228 		ret = clk_prepare_enable(ssi_private->clk);
1229 		if (ret) {
1230 			dev_err(&pdev->dev, "clk_prepare_enable failed: %d\n", ret);
1231 			return ret;
1232 		}
1233 	}
1234 
1235 	/* For those SLAVE implementations, we ignore non-baudclk cases
1236 	 * and, instead, abandon MASTER mode that needs baud clock.
1237 	 */
1238 	ssi_private->baudclk = devm_clk_get(&pdev->dev, "baud");
1239 	if (IS_ERR(ssi_private->baudclk))
1240 		dev_dbg(&pdev->dev, "could not get baud clock: %ld\n",
1241 			 PTR_ERR(ssi_private->baudclk));
1242 
1243 	/*
1244 	 * We have burstsize be "fifo_depth - 2" to match the SSI
1245 	 * watermark setting in fsl_ssi_startup().
1246 	 */
1247 	ssi_private->dma_params_tx.maxburst = ssi_private->fifo_depth - 2;
1248 	ssi_private->dma_params_rx.maxburst = ssi_private->fifo_depth - 2;
1249 	ssi_private->dma_params_tx.addr = ssi_private->ssi_phys + CCSR_SSI_STX0;
1250 	ssi_private->dma_params_rx.addr = ssi_private->ssi_phys + CCSR_SSI_SRX0;
1251 
1252 	ret = of_property_read_u32_array(np, "dmas", dmas, 4);
1253 	if (ssi_private->use_dma && !ret && dmas[2] == IMX_DMATYPE_SSI_DUAL) {
1254 		ssi_private->use_dual_fifo = true;
1255 		/* When using dual fifo mode, we need to keep watermark
1256 		 * as even numbers due to dma script limitation.
1257 		 */
1258 		ssi_private->dma_params_tx.maxburst &= ~0x1;
1259 		ssi_private->dma_params_rx.maxburst &= ~0x1;
1260 	}
1261 
1262 	if (!ssi_private->use_dma) {
1263 
1264 		/*
1265 		 * Some boards use an incompatible codec. To get it
1266 		 * working, we are using imx-fiq-pcm-audio, that
1267 		 * can handle those codecs. DMA is not possible in this
1268 		 * situation.
1269 		 */
1270 
1271 		ssi_private->fiq_params.irq = ssi_private->irq;
1272 		ssi_private->fiq_params.base = iomem;
1273 		ssi_private->fiq_params.dma_params_rx =
1274 			&ssi_private->dma_params_rx;
1275 		ssi_private->fiq_params.dma_params_tx =
1276 			&ssi_private->dma_params_tx;
1277 
1278 		ret = imx_pcm_fiq_init(pdev, &ssi_private->fiq_params);
1279 		if (ret)
1280 			goto error_pcm;
1281 	} else {
1282 		ret = imx_pcm_dma_init(pdev, IMX_SSI_DMABUF_SIZE);
1283 		if (ret)
1284 			goto error_pcm;
1285 	}
1286 
1287 	return 0;
1288 
1289 error_pcm:
1290 
1291 	if (!ssi_private->has_ipg_clk_name)
1292 		clk_disable_unprepare(ssi_private->clk);
1293 	return ret;
1294 }
1295 
1296 static void fsl_ssi_imx_clean(struct platform_device *pdev,
1297 		struct fsl_ssi_private *ssi_private)
1298 {
1299 	if (!ssi_private->use_dma)
1300 		imx_pcm_fiq_exit(pdev);
1301 	if (!ssi_private->has_ipg_clk_name)
1302 		clk_disable_unprepare(ssi_private->clk);
1303 }
1304 
1305 static int fsl_ssi_probe(struct platform_device *pdev)
1306 {
1307 	struct fsl_ssi_private *ssi_private;
1308 	int ret = 0;
1309 	struct device_node *np = pdev->dev.of_node;
1310 	const struct of_device_id *of_id;
1311 	const char *p, *sprop;
1312 	const uint32_t *iprop;
1313 	struct resource *res;
1314 	void __iomem *iomem;
1315 	char name[64];
1316 
1317 	of_id = of_match_device(fsl_ssi_ids, &pdev->dev);
1318 	if (!of_id || !of_id->data)
1319 		return -EINVAL;
1320 
1321 	ssi_private = devm_kzalloc(&pdev->dev, sizeof(*ssi_private),
1322 			GFP_KERNEL);
1323 	if (!ssi_private) {
1324 		dev_err(&pdev->dev, "could not allocate DAI object\n");
1325 		return -ENOMEM;
1326 	}
1327 
1328 	ssi_private->soc = of_id->data;
1329 
1330 	sprop = of_get_property(np, "fsl,mode", NULL);
1331 	if (sprop) {
1332 		if (!strcmp(sprop, "ac97-slave"))
1333 			ssi_private->dai_fmt = SND_SOC_DAIFMT_AC97;
1334 	}
1335 
1336 	ssi_private->use_dma = !of_property_read_bool(np,
1337 			"fsl,fiq-stream-filter");
1338 
1339 	if (fsl_ssi_is_ac97(ssi_private)) {
1340 		memcpy(&ssi_private->cpu_dai_drv, &fsl_ssi_ac97_dai,
1341 				sizeof(fsl_ssi_ac97_dai));
1342 
1343 		fsl_ac97_data = ssi_private;
1344 
1345 		ret = snd_soc_set_ac97_ops_of_reset(&fsl_ssi_ac97_ops, pdev);
1346 		if (ret) {
1347 			dev_err(&pdev->dev, "could not set AC'97 ops\n");
1348 			return ret;
1349 		}
1350 	} else {
1351 		/* Initialize this copy of the CPU DAI driver structure */
1352 		memcpy(&ssi_private->cpu_dai_drv, &fsl_ssi_dai_template,
1353 		       sizeof(fsl_ssi_dai_template));
1354 	}
1355 	ssi_private->cpu_dai_drv.name = dev_name(&pdev->dev);
1356 
1357 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1358 	iomem = devm_ioremap_resource(&pdev->dev, res);
1359 	if (IS_ERR(iomem))
1360 		return PTR_ERR(iomem);
1361 	ssi_private->ssi_phys = res->start;
1362 
1363 	ret = of_property_match_string(np, "clock-names", "ipg");
1364 	if (ret < 0) {
1365 		ssi_private->has_ipg_clk_name = false;
1366 		ssi_private->regs = devm_regmap_init_mmio(&pdev->dev, iomem,
1367 			&fsl_ssi_regconfig);
1368 	} else {
1369 		ssi_private->has_ipg_clk_name = true;
1370 		ssi_private->regs = devm_regmap_init_mmio_clk(&pdev->dev,
1371 			"ipg", iomem, &fsl_ssi_regconfig);
1372 	}
1373 	if (IS_ERR(ssi_private->regs)) {
1374 		dev_err(&pdev->dev, "Failed to init register map\n");
1375 		return PTR_ERR(ssi_private->regs);
1376 	}
1377 
1378 	ssi_private->irq = platform_get_irq(pdev, 0);
1379 	if (ssi_private->irq < 0) {
1380 		dev_err(&pdev->dev, "no irq for node %s\n", pdev->name);
1381 		return ssi_private->irq;
1382 	}
1383 
1384 	/* Are the RX and the TX clocks locked? */
1385 	if (!of_find_property(np, "fsl,ssi-asynchronous", NULL)) {
1386 		if (!fsl_ssi_is_ac97(ssi_private))
1387 			ssi_private->cpu_dai_drv.symmetric_rates = 1;
1388 
1389 		ssi_private->cpu_dai_drv.symmetric_channels = 1;
1390 		ssi_private->cpu_dai_drv.symmetric_samplebits = 1;
1391 	}
1392 
1393 	/* Determine the FIFO depth. */
1394 	iprop = of_get_property(np, "fsl,fifo-depth", NULL);
1395 	if (iprop)
1396 		ssi_private->fifo_depth = be32_to_cpup(iprop);
1397 	else
1398                 /* Older 8610 DTs didn't have the fifo-depth property */
1399 		ssi_private->fifo_depth = 8;
1400 
1401 	dev_set_drvdata(&pdev->dev, ssi_private);
1402 
1403 	if (ssi_private->soc->imx) {
1404 		ret = fsl_ssi_imx_probe(pdev, ssi_private, iomem);
1405 		if (ret)
1406 			return ret;
1407 	}
1408 
1409 	ret = devm_snd_soc_register_component(&pdev->dev, &fsl_ssi_component,
1410 					      &ssi_private->cpu_dai_drv, 1);
1411 	if (ret) {
1412 		dev_err(&pdev->dev, "failed to register DAI: %d\n", ret);
1413 		goto error_asoc_register;
1414 	}
1415 
1416 	if (ssi_private->use_dma) {
1417 		ret = devm_request_irq(&pdev->dev, ssi_private->irq,
1418 					fsl_ssi_isr, 0, dev_name(&pdev->dev),
1419 					ssi_private);
1420 		if (ret < 0) {
1421 			dev_err(&pdev->dev, "could not claim irq %u\n",
1422 					ssi_private->irq);
1423 			goto error_asoc_register;
1424 		}
1425 	}
1426 
1427 	ret = fsl_ssi_debugfs_create(&ssi_private->dbg_stats, &pdev->dev);
1428 	if (ret)
1429 		goto error_asoc_register;
1430 
1431 	/*
1432 	 * If codec-handle property is missing from SSI node, we assume
1433 	 * that the machine driver uses new binding which does not require
1434 	 * SSI driver to trigger machine driver's probe.
1435 	 */
1436 	if (!of_get_property(np, "codec-handle", NULL))
1437 		goto done;
1438 
1439 	/* Trigger the machine driver's probe function.  The platform driver
1440 	 * name of the machine driver is taken from /compatible property of the
1441 	 * device tree.  We also pass the address of the CPU DAI driver
1442 	 * structure.
1443 	 */
1444 	sprop = of_get_property(of_find_node_by_path("/"), "compatible", NULL);
1445 	/* Sometimes the compatible name has a "fsl," prefix, so we strip it. */
1446 	p = strrchr(sprop, ',');
1447 	if (p)
1448 		sprop = p + 1;
1449 	snprintf(name, sizeof(name), "snd-soc-%s", sprop);
1450 	make_lowercase(name);
1451 
1452 	ssi_private->pdev =
1453 		platform_device_register_data(&pdev->dev, name, 0, NULL, 0);
1454 	if (IS_ERR(ssi_private->pdev)) {
1455 		ret = PTR_ERR(ssi_private->pdev);
1456 		dev_err(&pdev->dev, "failed to register platform: %d\n", ret);
1457 		goto error_sound_card;
1458 	}
1459 
1460 done:
1461 	if (ssi_private->dai_fmt)
1462 		_fsl_ssi_set_dai_fmt(&pdev->dev, ssi_private,
1463 				     ssi_private->dai_fmt);
1464 
1465 	if (fsl_ssi_is_ac97(ssi_private)) {
1466 		u32 ssi_idx;
1467 
1468 		ret = of_property_read_u32(np, "cell-index", &ssi_idx);
1469 		if (ret) {
1470 			dev_err(&pdev->dev, "cannot get SSI index property\n");
1471 			goto error_sound_card;
1472 		}
1473 
1474 		ssi_private->pdev =
1475 			platform_device_register_data(NULL,
1476 					"ac97-codec", ssi_idx, NULL, 0);
1477 		if (IS_ERR(ssi_private->pdev)) {
1478 			ret = PTR_ERR(ssi_private->pdev);
1479 			dev_err(&pdev->dev,
1480 				"failed to register AC97 codec platform: %d\n",
1481 				ret);
1482 			goto error_sound_card;
1483 		}
1484 	}
1485 
1486 	return 0;
1487 
1488 error_sound_card:
1489 	fsl_ssi_debugfs_remove(&ssi_private->dbg_stats);
1490 
1491 error_asoc_register:
1492 	if (ssi_private->soc->imx)
1493 		fsl_ssi_imx_clean(pdev, ssi_private);
1494 
1495 	return ret;
1496 }
1497 
1498 static int fsl_ssi_remove(struct platform_device *pdev)
1499 {
1500 	struct fsl_ssi_private *ssi_private = dev_get_drvdata(&pdev->dev);
1501 
1502 	fsl_ssi_debugfs_remove(&ssi_private->dbg_stats);
1503 
1504 	if (ssi_private->pdev)
1505 		platform_device_unregister(ssi_private->pdev);
1506 
1507 	if (ssi_private->soc->imx)
1508 		fsl_ssi_imx_clean(pdev, ssi_private);
1509 
1510 	if (fsl_ssi_is_ac97(ssi_private))
1511 		snd_soc_set_ac97_ops(NULL);
1512 
1513 	return 0;
1514 }
1515 
1516 static struct platform_driver fsl_ssi_driver = {
1517 	.driver = {
1518 		.name = "fsl-ssi-dai",
1519 		.of_match_table = fsl_ssi_ids,
1520 	},
1521 	.probe = fsl_ssi_probe,
1522 	.remove = fsl_ssi_remove,
1523 };
1524 
1525 module_platform_driver(fsl_ssi_driver);
1526 
1527 MODULE_ALIAS("platform:fsl-ssi-dai");
1528 MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
1529 MODULE_DESCRIPTION("Freescale Synchronous Serial Interface (SSI) ASoC Driver");
1530 MODULE_LICENSE("GPL v2");
1531