xref: /linux/sound/soc/fsl/fsl_ssi.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
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_FORMAT_MASK) ==
253 		SND_SOC_DAIFMT_AC97;
254 }
255 
256 static bool fsl_ssi_is_i2s_master(struct fsl_ssi_private *ssi_private)
257 {
258 	return (ssi_private->dai_fmt & SND_SOC_DAIFMT_MASTER_MASK) ==
259 		SND_SOC_DAIFMT_CBS_CFS;
260 }
261 
262 static bool fsl_ssi_is_i2s_cbm_cfs(struct fsl_ssi_private *ssi_private)
263 {
264 	return (ssi_private->dai_fmt & SND_SOC_DAIFMT_MASTER_MASK) ==
265 		SND_SOC_DAIFMT_CBM_CFS;
266 }
267 /**
268  * fsl_ssi_isr: SSI interrupt handler
269  *
270  * Although it's possible to use the interrupt handler to send and receive
271  * data to/from the SSI, we use the DMA instead.  Programming is more
272  * complicated, but the performance is much better.
273  *
274  * This interrupt handler is used only to gather statistics.
275  *
276  * @irq: IRQ of the SSI device
277  * @dev_id: pointer to the ssi_private structure for this SSI device
278  */
279 static irqreturn_t fsl_ssi_isr(int irq, void *dev_id)
280 {
281 	struct fsl_ssi_private *ssi_private = dev_id;
282 	struct regmap *regs = ssi_private->regs;
283 	__be32 sisr;
284 	__be32 sisr2;
285 
286 	/* We got an interrupt, so read the status register to see what we
287 	   were interrupted for.  We mask it with the Interrupt Enable register
288 	   so that we only check for events that we're interested in.
289 	 */
290 	regmap_read(regs, CCSR_SSI_SISR, &sisr);
291 
292 	sisr2 = sisr & ssi_private->soc->sisr_write_mask;
293 	/* Clear the bits that we set */
294 	if (sisr2)
295 		regmap_write(regs, CCSR_SSI_SISR, sisr2);
296 
297 	fsl_ssi_dbg_isr(&ssi_private->dbg_stats, sisr);
298 
299 	return IRQ_HANDLED;
300 }
301 
302 /*
303  * Enable/Disable all rx/tx config flags at once.
304  */
305 static void fsl_ssi_rxtx_config(struct fsl_ssi_private *ssi_private,
306 		bool enable)
307 {
308 	struct regmap *regs = ssi_private->regs;
309 	struct fsl_ssi_rxtx_reg_val *vals = &ssi_private->rxtx_reg_val;
310 
311 	if (enable) {
312 		regmap_update_bits(regs, CCSR_SSI_SIER,
313 				vals->rx.sier | vals->tx.sier,
314 				vals->rx.sier | vals->tx.sier);
315 		regmap_update_bits(regs, CCSR_SSI_SRCR,
316 				vals->rx.srcr | vals->tx.srcr,
317 				vals->rx.srcr | vals->tx.srcr);
318 		regmap_update_bits(regs, CCSR_SSI_STCR,
319 				vals->rx.stcr | vals->tx.stcr,
320 				vals->rx.stcr | vals->tx.stcr);
321 	} else {
322 		regmap_update_bits(regs, CCSR_SSI_SRCR,
323 				vals->rx.srcr | vals->tx.srcr, 0);
324 		regmap_update_bits(regs, CCSR_SSI_STCR,
325 				vals->rx.stcr | vals->tx.stcr, 0);
326 		regmap_update_bits(regs, CCSR_SSI_SIER,
327 				vals->rx.sier | vals->tx.sier, 0);
328 	}
329 }
330 
331 /*
332  * Calculate the bits that have to be disabled for the current stream that is
333  * getting disabled. This keeps the bits enabled that are necessary for the
334  * second stream to work if 'stream_active' is true.
335  *
336  * Detailed calculation:
337  * These are the values that need to be active after disabling. For non-active
338  * second stream, this is 0:
339  *	vals_stream * !!stream_active
340  *
341  * The following computes the overall differences between the setup for the
342  * to-disable stream and the active stream, a simple XOR:
343  *	vals_disable ^ (vals_stream * !!(stream_active))
344  *
345  * The full expression adds a mask on all values we care about
346  */
347 #define fsl_ssi_disable_val(vals_disable, vals_stream, stream_active) \
348 	((vals_disable) & \
349 	 ((vals_disable) ^ ((vals_stream) * (u32)!!(stream_active))))
350 
351 /*
352  * Enable/Disable a ssi configuration. You have to pass either
353  * ssi_private->rxtx_reg_val.rx or tx as vals parameter.
354  */
355 static void fsl_ssi_config(struct fsl_ssi_private *ssi_private, bool enable,
356 		struct fsl_ssi_reg_val *vals)
357 {
358 	struct regmap *regs = ssi_private->regs;
359 	struct fsl_ssi_reg_val *avals;
360 	int nr_active_streams;
361 	u32 scr_val;
362 	int keep_active;
363 
364 	regmap_read(regs, CCSR_SSI_SCR, &scr_val);
365 
366 	nr_active_streams = !!(scr_val & CCSR_SSI_SCR_TE) +
367 				!!(scr_val & CCSR_SSI_SCR_RE);
368 
369 	if (nr_active_streams - 1 > 0)
370 		keep_active = 1;
371 	else
372 		keep_active = 0;
373 
374 	/* Find the other direction values rx or tx which we do not want to
375 	 * modify */
376 	if (&ssi_private->rxtx_reg_val.rx == vals)
377 		avals = &ssi_private->rxtx_reg_val.tx;
378 	else
379 		avals = &ssi_private->rxtx_reg_val.rx;
380 
381 	/* If vals should be disabled, start with disabling the unit */
382 	if (!enable) {
383 		u32 scr = fsl_ssi_disable_val(vals->scr, avals->scr,
384 				keep_active);
385 		regmap_update_bits(regs, CCSR_SSI_SCR, scr, 0);
386 	}
387 
388 	/*
389 	 * We are running on a SoC which does not support online SSI
390 	 * reconfiguration, so we have to enable all necessary flags at once
391 	 * even if we do not use them later (capture and playback configuration)
392 	 */
393 	if (ssi_private->soc->offline_config) {
394 		if ((enable && !nr_active_streams) ||
395 				(!enable && !keep_active))
396 			fsl_ssi_rxtx_config(ssi_private, enable);
397 
398 		goto config_done;
399 	}
400 
401 	/*
402 	 * Configure single direction units while the SSI unit is running
403 	 * (online configuration)
404 	 */
405 	if (enable) {
406 		regmap_update_bits(regs, CCSR_SSI_SIER, vals->sier, vals->sier);
407 		regmap_update_bits(regs, CCSR_SSI_SRCR, vals->srcr, vals->srcr);
408 		regmap_update_bits(regs, CCSR_SSI_STCR, vals->stcr, vals->stcr);
409 	} else {
410 		u32 sier;
411 		u32 srcr;
412 		u32 stcr;
413 
414 		/*
415 		 * Disabling the necessary flags for one of rx/tx while the
416 		 * other stream is active is a little bit more difficult. We
417 		 * have to disable only those flags that differ between both
418 		 * streams (rx XOR tx) and that are set in the stream that is
419 		 * disabled now. Otherwise we could alter flags of the other
420 		 * stream
421 		 */
422 
423 		/* These assignments are simply vals without bits set in avals*/
424 		sier = fsl_ssi_disable_val(vals->sier, avals->sier,
425 				keep_active);
426 		srcr = fsl_ssi_disable_val(vals->srcr, avals->srcr,
427 				keep_active);
428 		stcr = fsl_ssi_disable_val(vals->stcr, avals->stcr,
429 				keep_active);
430 
431 		regmap_update_bits(regs, CCSR_SSI_SRCR, srcr, 0);
432 		regmap_update_bits(regs, CCSR_SSI_STCR, stcr, 0);
433 		regmap_update_bits(regs, CCSR_SSI_SIER, sier, 0);
434 	}
435 
436 config_done:
437 	/* Enabling of subunits is done after configuration */
438 	if (enable)
439 		regmap_update_bits(regs, CCSR_SSI_SCR, vals->scr, vals->scr);
440 }
441 
442 
443 static void fsl_ssi_rx_config(struct fsl_ssi_private *ssi_private, bool enable)
444 {
445 	fsl_ssi_config(ssi_private, enable, &ssi_private->rxtx_reg_val.rx);
446 }
447 
448 static void fsl_ssi_tx_config(struct fsl_ssi_private *ssi_private, bool enable)
449 {
450 	fsl_ssi_config(ssi_private, enable, &ssi_private->rxtx_reg_val.tx);
451 }
452 
453 /*
454  * Setup rx/tx register values used to enable/disable the streams. These will
455  * be used later in fsl_ssi_config to setup the streams without the need to
456  * check for all different SSI modes.
457  */
458 static void fsl_ssi_setup_reg_vals(struct fsl_ssi_private *ssi_private)
459 {
460 	struct fsl_ssi_rxtx_reg_val *reg = &ssi_private->rxtx_reg_val;
461 
462 	reg->rx.sier = CCSR_SSI_SIER_RFF0_EN;
463 	reg->rx.srcr = CCSR_SSI_SRCR_RFEN0;
464 	reg->rx.scr = 0;
465 	reg->tx.sier = CCSR_SSI_SIER_TFE0_EN;
466 	reg->tx.stcr = CCSR_SSI_STCR_TFEN0;
467 	reg->tx.scr = 0;
468 
469 	if (!fsl_ssi_is_ac97(ssi_private)) {
470 		reg->rx.scr = CCSR_SSI_SCR_SSIEN | CCSR_SSI_SCR_RE;
471 		reg->rx.sier |= CCSR_SSI_SIER_RFF0_EN;
472 		reg->tx.scr = CCSR_SSI_SCR_SSIEN | CCSR_SSI_SCR_TE;
473 		reg->tx.sier |= CCSR_SSI_SIER_TFE0_EN;
474 	}
475 
476 	if (ssi_private->use_dma) {
477 		reg->rx.sier |= CCSR_SSI_SIER_RDMAE;
478 		reg->tx.sier |= CCSR_SSI_SIER_TDMAE;
479 	} else {
480 		reg->rx.sier |= CCSR_SSI_SIER_RIE;
481 		reg->tx.sier |= CCSR_SSI_SIER_TIE;
482 	}
483 
484 	reg->rx.sier |= FSLSSI_SIER_DBG_RX_FLAGS;
485 	reg->tx.sier |= FSLSSI_SIER_DBG_TX_FLAGS;
486 }
487 
488 static void fsl_ssi_setup_ac97(struct fsl_ssi_private *ssi_private)
489 {
490 	struct regmap *regs = ssi_private->regs;
491 
492 	/*
493 	 * Setup the clock control register
494 	 */
495 	regmap_write(regs, CCSR_SSI_STCCR,
496 			CCSR_SSI_SxCCR_WL(17) | CCSR_SSI_SxCCR_DC(13));
497 	regmap_write(regs, CCSR_SSI_SRCCR,
498 			CCSR_SSI_SxCCR_WL(17) | CCSR_SSI_SxCCR_DC(13));
499 
500 	/*
501 	 * Enable AC97 mode and startup the SSI
502 	 */
503 	regmap_write(regs, CCSR_SSI_SACNT,
504 			CCSR_SSI_SACNT_AC97EN | CCSR_SSI_SACNT_FV);
505 	regmap_write(regs, CCSR_SSI_SACCDIS, 0xff);
506 	regmap_write(regs, CCSR_SSI_SACCEN, 0x300);
507 
508 	/*
509 	 * Enable SSI, Transmit and Receive. AC97 has to communicate with the
510 	 * codec before a stream is started.
511 	 */
512 	regmap_update_bits(regs, CCSR_SSI_SCR,
513 			CCSR_SSI_SCR_SSIEN | CCSR_SSI_SCR_TE | CCSR_SSI_SCR_RE,
514 			CCSR_SSI_SCR_SSIEN | CCSR_SSI_SCR_TE | CCSR_SSI_SCR_RE);
515 
516 	regmap_write(regs, CCSR_SSI_SOR, CCSR_SSI_SOR_WAIT(3));
517 }
518 
519 /**
520  * fsl_ssi_startup: create a new substream
521  *
522  * This is the first function called when a stream is opened.
523  *
524  * If this is the first stream open, then grab the IRQ and program most of
525  * the SSI registers.
526  */
527 static int fsl_ssi_startup(struct snd_pcm_substream *substream,
528 			   struct snd_soc_dai *dai)
529 {
530 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
531 	struct fsl_ssi_private *ssi_private =
532 		snd_soc_dai_get_drvdata(rtd->cpu_dai);
533 	int ret;
534 
535 	ret = clk_prepare_enable(ssi_private->clk);
536 	if (ret)
537 		return ret;
538 
539 	/* When using dual fifo mode, it is safer to ensure an even period
540 	 * size. If appearing to an odd number while DMA always starts its
541 	 * task from fifo0, fifo1 would be neglected at the end of each
542 	 * period. But SSI would still access fifo1 with an invalid data.
543 	 */
544 	if (ssi_private->use_dual_fifo)
545 		snd_pcm_hw_constraint_step(substream->runtime, 0,
546 				SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 2);
547 
548 	return 0;
549 }
550 
551 /**
552  * fsl_ssi_shutdown: shutdown the SSI
553  *
554  */
555 static void fsl_ssi_shutdown(struct snd_pcm_substream *substream,
556 				struct snd_soc_dai *dai)
557 {
558 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
559 	struct fsl_ssi_private *ssi_private =
560 		snd_soc_dai_get_drvdata(rtd->cpu_dai);
561 
562 	clk_disable_unprepare(ssi_private->clk);
563 
564 }
565 
566 /**
567  * fsl_ssi_set_bclk - configure Digital Audio Interface bit clock
568  *
569  * Note: This function can be only called when using SSI as DAI master
570  *
571  * Quick instruction for parameters:
572  * freq: Output BCLK frequency = samplerate * 32 (fixed) * channels
573  * dir: SND_SOC_CLOCK_OUT -> TxBCLK, SND_SOC_CLOCK_IN -> RxBCLK.
574  */
575 static int fsl_ssi_set_bclk(struct snd_pcm_substream *substream,
576 		struct snd_soc_dai *cpu_dai,
577 		struct snd_pcm_hw_params *hw_params)
578 {
579 	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(cpu_dai);
580 	struct regmap *regs = ssi_private->regs;
581 	int synchronous = ssi_private->cpu_dai_drv.symmetric_rates, ret;
582 	u32 pm = 999, div2, psr, stccr, mask, afreq, factor, i;
583 	unsigned long clkrate, baudrate, tmprate;
584 	u64 sub, savesub = 100000;
585 	unsigned int freq;
586 	bool baudclk_is_used;
587 
588 	/* Prefer the explicitly set bitclock frequency */
589 	if (ssi_private->bitclk_freq)
590 		freq = ssi_private->bitclk_freq;
591 	else
592 		freq = params_channels(hw_params) * 32 * params_rate(hw_params);
593 
594 	/* Don't apply it to any non-baudclk circumstance */
595 	if (IS_ERR(ssi_private->baudclk))
596 		return -EINVAL;
597 
598 	baudclk_is_used = ssi_private->baudclk_streams & ~(BIT(substream->stream));
599 
600 	/* It should be already enough to divide clock by setting pm alone */
601 	psr = 0;
602 	div2 = 0;
603 
604 	factor = (div2 + 1) * (7 * psr + 1) * 2;
605 
606 	for (i = 0; i < 255; i++) {
607 		tmprate = freq * factor * (i + 1);
608 
609 		if (baudclk_is_used)
610 			clkrate = clk_get_rate(ssi_private->baudclk);
611 		else
612 			clkrate = clk_round_rate(ssi_private->baudclk, tmprate);
613 
614 		/*
615 		 * Hardware limitation: The bclk rate must be
616 		 * never greater than 1/5 IPG clock rate
617 		 */
618 		if (clkrate * 5 > clk_get_rate(ssi_private->clk))
619 			continue;
620 
621 		clkrate /= factor;
622 		afreq = clkrate / (i + 1);
623 
624 		if (freq == afreq)
625 			sub = 0;
626 		else if (freq / afreq == 1)
627 			sub = freq - afreq;
628 		else if (afreq / freq == 1)
629 			sub = afreq - freq;
630 		else
631 			continue;
632 
633 		/* Calculate the fraction */
634 		sub *= 100000;
635 		do_div(sub, freq);
636 
637 		if (sub < savesub && !(i == 0 && psr == 0 && div2 == 0)) {
638 			baudrate = tmprate;
639 			savesub = sub;
640 			pm = i;
641 		}
642 
643 		/* We are lucky */
644 		if (savesub == 0)
645 			break;
646 	}
647 
648 	/* No proper pm found if it is still remaining the initial value */
649 	if (pm == 999) {
650 		dev_err(cpu_dai->dev, "failed to handle the required sysclk\n");
651 		return -EINVAL;
652 	}
653 
654 	stccr = CCSR_SSI_SxCCR_PM(pm + 1) | (div2 ? CCSR_SSI_SxCCR_DIV2 : 0) |
655 		(psr ? CCSR_SSI_SxCCR_PSR : 0);
656 	mask = CCSR_SSI_SxCCR_PM_MASK | CCSR_SSI_SxCCR_DIV2 |
657 		CCSR_SSI_SxCCR_PSR;
658 
659 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK || synchronous)
660 		regmap_update_bits(regs, CCSR_SSI_STCCR, mask, stccr);
661 	else
662 		regmap_update_bits(regs, CCSR_SSI_SRCCR, mask, stccr);
663 
664 	if (!baudclk_is_used) {
665 		ret = clk_set_rate(ssi_private->baudclk, baudrate);
666 		if (ret) {
667 			dev_err(cpu_dai->dev, "failed to set baudclk rate\n");
668 			return -EINVAL;
669 		}
670 	}
671 
672 	return 0;
673 }
674 
675 static int fsl_ssi_set_dai_sysclk(struct snd_soc_dai *cpu_dai,
676 		int clk_id, unsigned int freq, int dir)
677 {
678 	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(cpu_dai);
679 
680 	ssi_private->bitclk_freq = freq;
681 
682 	return 0;
683 }
684 
685 /**
686  * fsl_ssi_hw_params - program the sample size
687  *
688  * Most of the SSI registers have been programmed in the startup function,
689  * but the word length must be programmed here.  Unfortunately, programming
690  * the SxCCR.WL bits requires the SSI to be temporarily disabled.  This can
691  * cause a problem with supporting simultaneous playback and capture.  If
692  * the SSI is already playing a stream, then that stream may be temporarily
693  * stopped when you start capture.
694  *
695  * Note: The SxCCR.DC and SxCCR.PM bits are only used if the SSI is the
696  * clock master.
697  */
698 static int fsl_ssi_hw_params(struct snd_pcm_substream *substream,
699 	struct snd_pcm_hw_params *hw_params, struct snd_soc_dai *cpu_dai)
700 {
701 	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(cpu_dai);
702 	struct regmap *regs = ssi_private->regs;
703 	unsigned int channels = params_channels(hw_params);
704 	unsigned int sample_size =
705 		snd_pcm_format_width(params_format(hw_params));
706 	u32 wl = CCSR_SSI_SxCCR_WL(sample_size);
707 	int ret;
708 	u32 scr_val;
709 	int enabled;
710 
711 	regmap_read(regs, CCSR_SSI_SCR, &scr_val);
712 	enabled = scr_val & CCSR_SSI_SCR_SSIEN;
713 
714 	/*
715 	 * If we're in synchronous mode, and the SSI is already enabled,
716 	 * then STCCR is already set properly.
717 	 */
718 	if (enabled && ssi_private->cpu_dai_drv.symmetric_rates)
719 		return 0;
720 
721 	if (fsl_ssi_is_i2s_master(ssi_private)) {
722 		ret = fsl_ssi_set_bclk(substream, cpu_dai, hw_params);
723 		if (ret)
724 			return ret;
725 
726 		/* Do not enable the clock if it is already enabled */
727 		if (!(ssi_private->baudclk_streams & BIT(substream->stream))) {
728 			ret = clk_prepare_enable(ssi_private->baudclk);
729 			if (ret)
730 				return ret;
731 
732 			ssi_private->baudclk_streams |= BIT(substream->stream);
733 		}
734 	}
735 
736 	if (!fsl_ssi_is_ac97(ssi_private)) {
737 		u8 i2smode;
738 		/*
739 		 * Switch to normal net mode in order to have a frame sync
740 		 * signal every 32 bits instead of 16 bits
741 		 */
742 		if (fsl_ssi_is_i2s_cbm_cfs(ssi_private) && sample_size == 16)
743 			i2smode = CCSR_SSI_SCR_I2S_MODE_NORMAL |
744 				CCSR_SSI_SCR_NET;
745 		else
746 			i2smode = ssi_private->i2s_mode;
747 
748 		regmap_update_bits(regs, CCSR_SSI_SCR,
749 				CCSR_SSI_SCR_NET | CCSR_SSI_SCR_I2S_MODE_MASK,
750 				channels == 1 ? 0 : i2smode);
751 	}
752 
753 	/*
754 	 * FIXME: The documentation says that SxCCR[WL] should not be
755 	 * modified while the SSI is enabled.  The only time this can
756 	 * happen is if we're trying to do simultaneous playback and
757 	 * capture in asynchronous mode.  Unfortunately, I have been enable
758 	 * to get that to work at all on the P1022DS.  Therefore, we don't
759 	 * bother to disable/enable the SSI when setting SxCCR[WL], because
760 	 * the SSI will stop anyway.  Maybe one day, this will get fixed.
761 	 */
762 
763 	/* In synchronous mode, the SSI uses STCCR for capture */
764 	if ((substream->stream == SNDRV_PCM_STREAM_PLAYBACK) ||
765 	    ssi_private->cpu_dai_drv.symmetric_rates)
766 		regmap_update_bits(regs, CCSR_SSI_STCCR, CCSR_SSI_SxCCR_WL_MASK,
767 				wl);
768 	else
769 		regmap_update_bits(regs, CCSR_SSI_SRCCR, CCSR_SSI_SxCCR_WL_MASK,
770 				wl);
771 
772 	return 0;
773 }
774 
775 static int fsl_ssi_hw_free(struct snd_pcm_substream *substream,
776 		struct snd_soc_dai *cpu_dai)
777 {
778 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
779 	struct fsl_ssi_private *ssi_private =
780 		snd_soc_dai_get_drvdata(rtd->cpu_dai);
781 
782 	if (fsl_ssi_is_i2s_master(ssi_private) &&
783 			ssi_private->baudclk_streams & BIT(substream->stream)) {
784 		clk_disable_unprepare(ssi_private->baudclk);
785 		ssi_private->baudclk_streams &= ~BIT(substream->stream);
786 	}
787 
788 	return 0;
789 }
790 
791 static int _fsl_ssi_set_dai_fmt(struct device *dev,
792 				struct fsl_ssi_private *ssi_private,
793 				unsigned int fmt)
794 {
795 	struct regmap *regs = ssi_private->regs;
796 	u32 strcr = 0, stcr, srcr, scr, mask;
797 	u8 wm;
798 
799 	ssi_private->dai_fmt = fmt;
800 
801 	if (fsl_ssi_is_i2s_master(ssi_private) && IS_ERR(ssi_private->baudclk)) {
802 		dev_err(dev, "baudclk is missing which is necessary for master mode\n");
803 		return -EINVAL;
804 	}
805 
806 	fsl_ssi_setup_reg_vals(ssi_private);
807 
808 	regmap_read(regs, CCSR_SSI_SCR, &scr);
809 	scr &= ~(CCSR_SSI_SCR_SYN | CCSR_SSI_SCR_I2S_MODE_MASK);
810 	scr |= CCSR_SSI_SCR_SYNC_TX_FS;
811 
812 	mask = CCSR_SSI_STCR_TXBIT0 | CCSR_SSI_STCR_TFDIR | CCSR_SSI_STCR_TXDIR |
813 		CCSR_SSI_STCR_TSCKP | CCSR_SSI_STCR_TFSI | CCSR_SSI_STCR_TFSL |
814 		CCSR_SSI_STCR_TEFS;
815 	regmap_read(regs, CCSR_SSI_STCR, &stcr);
816 	regmap_read(regs, CCSR_SSI_SRCR, &srcr);
817 	stcr &= ~mask;
818 	srcr &= ~mask;
819 
820 	ssi_private->i2s_mode = CCSR_SSI_SCR_NET;
821 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
822 	case SND_SOC_DAIFMT_I2S:
823 		switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
824 		case SND_SOC_DAIFMT_CBM_CFS:
825 		case SND_SOC_DAIFMT_CBS_CFS:
826 			ssi_private->i2s_mode |= CCSR_SSI_SCR_I2S_MODE_MASTER;
827 			regmap_update_bits(regs, CCSR_SSI_STCCR,
828 					CCSR_SSI_SxCCR_DC_MASK,
829 					CCSR_SSI_SxCCR_DC(2));
830 			regmap_update_bits(regs, CCSR_SSI_SRCCR,
831 					CCSR_SSI_SxCCR_DC_MASK,
832 					CCSR_SSI_SxCCR_DC(2));
833 			break;
834 		case SND_SOC_DAIFMT_CBM_CFM:
835 			ssi_private->i2s_mode |= CCSR_SSI_SCR_I2S_MODE_SLAVE;
836 			break;
837 		default:
838 			return -EINVAL;
839 		}
840 
841 		/* Data on rising edge of bclk, frame low, 1clk before data */
842 		strcr |= CCSR_SSI_STCR_TFSI | CCSR_SSI_STCR_TSCKP |
843 			CCSR_SSI_STCR_TXBIT0 | CCSR_SSI_STCR_TEFS;
844 		break;
845 	case SND_SOC_DAIFMT_LEFT_J:
846 		/* Data on rising edge of bclk, frame high */
847 		strcr |= CCSR_SSI_STCR_TXBIT0 | CCSR_SSI_STCR_TSCKP;
848 		break;
849 	case SND_SOC_DAIFMT_DSP_A:
850 		/* Data on rising edge of bclk, frame high, 1clk before data */
851 		strcr |= CCSR_SSI_STCR_TFSL | CCSR_SSI_STCR_TSCKP |
852 			CCSR_SSI_STCR_TXBIT0 | CCSR_SSI_STCR_TEFS;
853 		break;
854 	case SND_SOC_DAIFMT_DSP_B:
855 		/* Data on rising edge of bclk, frame high */
856 		strcr |= CCSR_SSI_STCR_TFSL | CCSR_SSI_STCR_TSCKP |
857 			CCSR_SSI_STCR_TXBIT0;
858 		break;
859 	case SND_SOC_DAIFMT_AC97:
860 		ssi_private->i2s_mode |= CCSR_SSI_SCR_I2S_MODE_NORMAL;
861 		break;
862 	default:
863 		return -EINVAL;
864 	}
865 	scr |= ssi_private->i2s_mode;
866 
867 	/* DAI clock inversion */
868 	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
869 	case SND_SOC_DAIFMT_NB_NF:
870 		/* Nothing to do for both normal cases */
871 		break;
872 	case SND_SOC_DAIFMT_IB_NF:
873 		/* Invert bit clock */
874 		strcr ^= CCSR_SSI_STCR_TSCKP;
875 		break;
876 	case SND_SOC_DAIFMT_NB_IF:
877 		/* Invert frame clock */
878 		strcr ^= CCSR_SSI_STCR_TFSI;
879 		break;
880 	case SND_SOC_DAIFMT_IB_IF:
881 		/* Invert both clocks */
882 		strcr ^= CCSR_SSI_STCR_TSCKP;
883 		strcr ^= CCSR_SSI_STCR_TFSI;
884 		break;
885 	default:
886 		return -EINVAL;
887 	}
888 
889 	/* DAI clock master masks */
890 	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
891 	case SND_SOC_DAIFMT_CBS_CFS:
892 		strcr |= CCSR_SSI_STCR_TFDIR | CCSR_SSI_STCR_TXDIR;
893 		scr |= CCSR_SSI_SCR_SYS_CLK_EN;
894 		break;
895 	case SND_SOC_DAIFMT_CBM_CFM:
896 		scr &= ~CCSR_SSI_SCR_SYS_CLK_EN;
897 		break;
898 	case SND_SOC_DAIFMT_CBM_CFS:
899 		strcr &= ~CCSR_SSI_STCR_TXDIR;
900 		strcr |= CCSR_SSI_STCR_TFDIR;
901 		scr &= ~CCSR_SSI_SCR_SYS_CLK_EN;
902 		break;
903 	default:
904 		if (!fsl_ssi_is_ac97(ssi_private))
905 			return -EINVAL;
906 	}
907 
908 	stcr |= strcr;
909 	srcr |= strcr;
910 
911 	if (ssi_private->cpu_dai_drv.symmetric_rates
912 			|| fsl_ssi_is_ac97(ssi_private)) {
913 		/* Need to clear RXDIR when using SYNC or AC97 mode */
914 		srcr &= ~CCSR_SSI_SRCR_RXDIR;
915 		scr |= CCSR_SSI_SCR_SYN;
916 	}
917 
918 	regmap_write(regs, CCSR_SSI_STCR, stcr);
919 	regmap_write(regs, CCSR_SSI_SRCR, srcr);
920 	regmap_write(regs, CCSR_SSI_SCR, scr);
921 
922 	/*
923 	 * Set the watermark for transmit FIFI 0 and receive FIFO 0. We don't
924 	 * use FIFO 1. We program the transmit water to signal a DMA transfer
925 	 * if there are only two (or fewer) elements left in the FIFO. Two
926 	 * elements equals one frame (left channel, right channel). This value,
927 	 * however, depends on the depth of the transmit buffer.
928 	 *
929 	 * We set the watermark on the same level as the DMA burstsize.  For
930 	 * fiq it is probably better to use the biggest possible watermark
931 	 * size.
932 	 */
933 	if (ssi_private->use_dma)
934 		wm = ssi_private->fifo_depth - 2;
935 	else
936 		wm = ssi_private->fifo_depth;
937 
938 	regmap_write(regs, CCSR_SSI_SFCSR,
939 			CCSR_SSI_SFCSR_TFWM0(wm) | CCSR_SSI_SFCSR_RFWM0(wm) |
940 			CCSR_SSI_SFCSR_TFWM1(wm) | CCSR_SSI_SFCSR_RFWM1(wm));
941 
942 	if (ssi_private->use_dual_fifo) {
943 		regmap_update_bits(regs, CCSR_SSI_SRCR, CCSR_SSI_SRCR_RFEN1,
944 				CCSR_SSI_SRCR_RFEN1);
945 		regmap_update_bits(regs, CCSR_SSI_STCR, CCSR_SSI_STCR_TFEN1,
946 				CCSR_SSI_STCR_TFEN1);
947 		regmap_update_bits(regs, CCSR_SSI_SCR, CCSR_SSI_SCR_TCH_EN,
948 				CCSR_SSI_SCR_TCH_EN);
949 	}
950 
951 	if ((fmt & SND_SOC_DAIFMT_FORMAT_MASK) == SND_SOC_DAIFMT_AC97)
952 		fsl_ssi_setup_ac97(ssi_private);
953 
954 	return 0;
955 
956 }
957 
958 /**
959  * fsl_ssi_set_dai_fmt - configure Digital Audio Interface Format.
960  */
961 static int fsl_ssi_set_dai_fmt(struct snd_soc_dai *cpu_dai, unsigned int fmt)
962 {
963 	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(cpu_dai);
964 
965 	return _fsl_ssi_set_dai_fmt(cpu_dai->dev, ssi_private, fmt);
966 }
967 
968 /**
969  * fsl_ssi_set_dai_tdm_slot - set TDM slot number
970  *
971  * Note: This function can be only called when using SSI as DAI master
972  */
973 static int fsl_ssi_set_dai_tdm_slot(struct snd_soc_dai *cpu_dai, u32 tx_mask,
974 				u32 rx_mask, int slots, int slot_width)
975 {
976 	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(cpu_dai);
977 	struct regmap *regs = ssi_private->regs;
978 	u32 val;
979 
980 	/* The slot number should be >= 2 if using Network mode or I2S mode */
981 	regmap_read(regs, CCSR_SSI_SCR, &val);
982 	val &= CCSR_SSI_SCR_I2S_MODE_MASK | CCSR_SSI_SCR_NET;
983 	if (val && slots < 2) {
984 		dev_err(cpu_dai->dev, "slot number should be >= 2 in I2S or NET\n");
985 		return -EINVAL;
986 	}
987 
988 	regmap_update_bits(regs, CCSR_SSI_STCCR, CCSR_SSI_SxCCR_DC_MASK,
989 			CCSR_SSI_SxCCR_DC(slots));
990 	regmap_update_bits(regs, CCSR_SSI_SRCCR, CCSR_SSI_SxCCR_DC_MASK,
991 			CCSR_SSI_SxCCR_DC(slots));
992 
993 	/* The register SxMSKs needs SSI to provide essential clock due to
994 	 * hardware design. So we here temporarily enable SSI to set them.
995 	 */
996 	regmap_read(regs, CCSR_SSI_SCR, &val);
997 	val &= CCSR_SSI_SCR_SSIEN;
998 	regmap_update_bits(regs, CCSR_SSI_SCR, CCSR_SSI_SCR_SSIEN,
999 			CCSR_SSI_SCR_SSIEN);
1000 
1001 	regmap_write(regs, CCSR_SSI_STMSK, ~tx_mask);
1002 	regmap_write(regs, CCSR_SSI_SRMSK, ~rx_mask);
1003 
1004 	regmap_update_bits(regs, CCSR_SSI_SCR, CCSR_SSI_SCR_SSIEN, val);
1005 
1006 	return 0;
1007 }
1008 
1009 /**
1010  * fsl_ssi_trigger: start and stop the DMA transfer.
1011  *
1012  * This function is called by ALSA to start, stop, pause, and resume the DMA
1013  * transfer of data.
1014  *
1015  * The DMA channel is in external master start and pause mode, which
1016  * means the SSI completely controls the flow of data.
1017  */
1018 static int fsl_ssi_trigger(struct snd_pcm_substream *substream, int cmd,
1019 			   struct snd_soc_dai *dai)
1020 {
1021 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
1022 	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(rtd->cpu_dai);
1023 	struct regmap *regs = ssi_private->regs;
1024 
1025 	switch (cmd) {
1026 	case SNDRV_PCM_TRIGGER_START:
1027 	case SNDRV_PCM_TRIGGER_RESUME:
1028 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1029 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
1030 			fsl_ssi_tx_config(ssi_private, true);
1031 		else
1032 			fsl_ssi_rx_config(ssi_private, true);
1033 		break;
1034 
1035 	case SNDRV_PCM_TRIGGER_STOP:
1036 	case SNDRV_PCM_TRIGGER_SUSPEND:
1037 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1038 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
1039 			fsl_ssi_tx_config(ssi_private, false);
1040 		else
1041 			fsl_ssi_rx_config(ssi_private, false);
1042 		break;
1043 
1044 	default:
1045 		return -EINVAL;
1046 	}
1047 
1048 	if (fsl_ssi_is_ac97(ssi_private)) {
1049 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
1050 			regmap_write(regs, CCSR_SSI_SOR, CCSR_SSI_SOR_TX_CLR);
1051 		else
1052 			regmap_write(regs, CCSR_SSI_SOR, CCSR_SSI_SOR_RX_CLR);
1053 	}
1054 
1055 	return 0;
1056 }
1057 
1058 static int fsl_ssi_dai_probe(struct snd_soc_dai *dai)
1059 {
1060 	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(dai);
1061 
1062 	if (ssi_private->soc->imx && ssi_private->use_dma) {
1063 		dai->playback_dma_data = &ssi_private->dma_params_tx;
1064 		dai->capture_dma_data = &ssi_private->dma_params_rx;
1065 	}
1066 
1067 	return 0;
1068 }
1069 
1070 static const struct snd_soc_dai_ops fsl_ssi_dai_ops = {
1071 	.startup	= fsl_ssi_startup,
1072 	.shutdown       = fsl_ssi_shutdown,
1073 	.hw_params	= fsl_ssi_hw_params,
1074 	.hw_free	= fsl_ssi_hw_free,
1075 	.set_fmt	= fsl_ssi_set_dai_fmt,
1076 	.set_sysclk	= fsl_ssi_set_dai_sysclk,
1077 	.set_tdm_slot	= fsl_ssi_set_dai_tdm_slot,
1078 	.trigger	= fsl_ssi_trigger,
1079 };
1080 
1081 /* Template for the CPU dai driver structure */
1082 static struct snd_soc_dai_driver fsl_ssi_dai_template = {
1083 	.probe = fsl_ssi_dai_probe,
1084 	.playback = {
1085 		.stream_name = "CPU-Playback",
1086 		.channels_min = 1,
1087 		.channels_max = 2,
1088 		.rates = FSLSSI_I2S_RATES,
1089 		.formats = FSLSSI_I2S_FORMATS,
1090 	},
1091 	.capture = {
1092 		.stream_name = "CPU-Capture",
1093 		.channels_min = 1,
1094 		.channels_max = 2,
1095 		.rates = FSLSSI_I2S_RATES,
1096 		.formats = FSLSSI_I2S_FORMATS,
1097 	},
1098 	.ops = &fsl_ssi_dai_ops,
1099 };
1100 
1101 static const struct snd_soc_component_driver fsl_ssi_component = {
1102 	.name		= "fsl-ssi",
1103 };
1104 
1105 static struct snd_soc_dai_driver fsl_ssi_ac97_dai = {
1106 	.bus_control = true,
1107 	.probe = fsl_ssi_dai_probe,
1108 	.playback = {
1109 		.stream_name = "AC97 Playback",
1110 		.channels_min = 2,
1111 		.channels_max = 2,
1112 		.rates = SNDRV_PCM_RATE_8000_48000,
1113 		.formats = SNDRV_PCM_FMTBIT_S16_LE,
1114 	},
1115 	.capture = {
1116 		.stream_name = "AC97 Capture",
1117 		.channels_min = 2,
1118 		.channels_max = 2,
1119 		.rates = SNDRV_PCM_RATE_48000,
1120 		.formats = SNDRV_PCM_FMTBIT_S16_LE,
1121 	},
1122 	.ops = &fsl_ssi_dai_ops,
1123 };
1124 
1125 
1126 static struct fsl_ssi_private *fsl_ac97_data;
1127 
1128 static void fsl_ssi_ac97_write(struct snd_ac97 *ac97, unsigned short reg,
1129 		unsigned short val)
1130 {
1131 	struct regmap *regs = fsl_ac97_data->regs;
1132 	unsigned int lreg;
1133 	unsigned int lval;
1134 	int ret;
1135 
1136 	if (reg > 0x7f)
1137 		return;
1138 
1139 	ret = clk_prepare_enable(fsl_ac97_data->clk);
1140 	if (ret) {
1141 		pr_err("ac97 write clk_prepare_enable failed: %d\n",
1142 			ret);
1143 		return;
1144 	}
1145 
1146 	lreg = reg <<  12;
1147 	regmap_write(regs, CCSR_SSI_SACADD, lreg);
1148 
1149 	lval = val << 4;
1150 	regmap_write(regs, CCSR_SSI_SACDAT, lval);
1151 
1152 	regmap_update_bits(regs, CCSR_SSI_SACNT, CCSR_SSI_SACNT_RDWR_MASK,
1153 			CCSR_SSI_SACNT_WR);
1154 	udelay(100);
1155 
1156 	clk_disable_unprepare(fsl_ac97_data->clk);
1157 }
1158 
1159 static unsigned short fsl_ssi_ac97_read(struct snd_ac97 *ac97,
1160 		unsigned short reg)
1161 {
1162 	struct regmap *regs = fsl_ac97_data->regs;
1163 
1164 	unsigned short val = -1;
1165 	u32 reg_val;
1166 	unsigned int lreg;
1167 	int ret;
1168 
1169 	ret = clk_prepare_enable(fsl_ac97_data->clk);
1170 	if (ret) {
1171 		pr_err("ac97 read clk_prepare_enable failed: %d\n",
1172 			ret);
1173 		return -1;
1174 	}
1175 
1176 	lreg = (reg & 0x7f) <<  12;
1177 	regmap_write(regs, CCSR_SSI_SACADD, lreg);
1178 	regmap_update_bits(regs, CCSR_SSI_SACNT, CCSR_SSI_SACNT_RDWR_MASK,
1179 			CCSR_SSI_SACNT_RD);
1180 
1181 	udelay(100);
1182 
1183 	regmap_read(regs, CCSR_SSI_SACDAT, &reg_val);
1184 	val = (reg_val >> 4) & 0xffff;
1185 
1186 	clk_disable_unprepare(fsl_ac97_data->clk);
1187 
1188 	return val;
1189 }
1190 
1191 static struct snd_ac97_bus_ops fsl_ssi_ac97_ops = {
1192 	.read		= fsl_ssi_ac97_read,
1193 	.write		= fsl_ssi_ac97_write,
1194 };
1195 
1196 /**
1197  * Make every character in a string lower-case
1198  */
1199 static void make_lowercase(char *s)
1200 {
1201 	char *p = s;
1202 	char c;
1203 
1204 	while ((c = *p)) {
1205 		if ((c >= 'A') && (c <= 'Z'))
1206 			*p = c + ('a' - 'A');
1207 		p++;
1208 	}
1209 }
1210 
1211 static int fsl_ssi_imx_probe(struct platform_device *pdev,
1212 		struct fsl_ssi_private *ssi_private, void __iomem *iomem)
1213 {
1214 	struct device_node *np = pdev->dev.of_node;
1215 	u32 dmas[4];
1216 	int ret;
1217 
1218 	if (ssi_private->has_ipg_clk_name)
1219 		ssi_private->clk = devm_clk_get(&pdev->dev, "ipg");
1220 	else
1221 		ssi_private->clk = devm_clk_get(&pdev->dev, NULL);
1222 	if (IS_ERR(ssi_private->clk)) {
1223 		ret = PTR_ERR(ssi_private->clk);
1224 		dev_err(&pdev->dev, "could not get clock: %d\n", ret);
1225 		return ret;
1226 	}
1227 
1228 	if (!ssi_private->has_ipg_clk_name) {
1229 		ret = clk_prepare_enable(ssi_private->clk);
1230 		if (ret) {
1231 			dev_err(&pdev->dev, "clk_prepare_enable failed: %d\n", ret);
1232 			return ret;
1233 		}
1234 	}
1235 
1236 	/* For those SLAVE implementations, we ignore non-baudclk cases
1237 	 * and, instead, abandon MASTER mode that needs baud clock.
1238 	 */
1239 	ssi_private->baudclk = devm_clk_get(&pdev->dev, "baud");
1240 	if (IS_ERR(ssi_private->baudclk))
1241 		dev_dbg(&pdev->dev, "could not get baud clock: %ld\n",
1242 			 PTR_ERR(ssi_private->baudclk));
1243 
1244 	/*
1245 	 * We have burstsize be "fifo_depth - 2" to match the SSI
1246 	 * watermark setting in fsl_ssi_startup().
1247 	 */
1248 	ssi_private->dma_params_tx.maxburst = ssi_private->fifo_depth - 2;
1249 	ssi_private->dma_params_rx.maxburst = ssi_private->fifo_depth - 2;
1250 	ssi_private->dma_params_tx.addr = ssi_private->ssi_phys + CCSR_SSI_STX0;
1251 	ssi_private->dma_params_rx.addr = ssi_private->ssi_phys + CCSR_SSI_SRX0;
1252 
1253 	ret = of_property_read_u32_array(np, "dmas", dmas, 4);
1254 	if (ssi_private->use_dma && !ret && dmas[2] == IMX_DMATYPE_SSI_DUAL) {
1255 		ssi_private->use_dual_fifo = true;
1256 		/* When using dual fifo mode, we need to keep watermark
1257 		 * as even numbers due to dma script limitation.
1258 		 */
1259 		ssi_private->dma_params_tx.maxburst &= ~0x1;
1260 		ssi_private->dma_params_rx.maxburst &= ~0x1;
1261 	}
1262 
1263 	if (!ssi_private->use_dma) {
1264 
1265 		/*
1266 		 * Some boards use an incompatible codec. To get it
1267 		 * working, we are using imx-fiq-pcm-audio, that
1268 		 * can handle those codecs. DMA is not possible in this
1269 		 * situation.
1270 		 */
1271 
1272 		ssi_private->fiq_params.irq = ssi_private->irq;
1273 		ssi_private->fiq_params.base = iomem;
1274 		ssi_private->fiq_params.dma_params_rx =
1275 			&ssi_private->dma_params_rx;
1276 		ssi_private->fiq_params.dma_params_tx =
1277 			&ssi_private->dma_params_tx;
1278 
1279 		ret = imx_pcm_fiq_init(pdev, &ssi_private->fiq_params);
1280 		if (ret)
1281 			goto error_pcm;
1282 	} else {
1283 		ret = imx_pcm_dma_init(pdev, IMX_SSI_DMABUF_SIZE);
1284 		if (ret)
1285 			goto error_pcm;
1286 	}
1287 
1288 	return 0;
1289 
1290 error_pcm:
1291 
1292 	if (!ssi_private->has_ipg_clk_name)
1293 		clk_disable_unprepare(ssi_private->clk);
1294 	return ret;
1295 }
1296 
1297 static void fsl_ssi_imx_clean(struct platform_device *pdev,
1298 		struct fsl_ssi_private *ssi_private)
1299 {
1300 	if (!ssi_private->use_dma)
1301 		imx_pcm_fiq_exit(pdev);
1302 	if (!ssi_private->has_ipg_clk_name)
1303 		clk_disable_unprepare(ssi_private->clk);
1304 }
1305 
1306 static int fsl_ssi_probe(struct platform_device *pdev)
1307 {
1308 	struct fsl_ssi_private *ssi_private;
1309 	int ret = 0;
1310 	struct device_node *np = pdev->dev.of_node;
1311 	const struct of_device_id *of_id;
1312 	const char *p, *sprop;
1313 	const uint32_t *iprop;
1314 	struct resource *res;
1315 	void __iomem *iomem;
1316 	char name[64];
1317 
1318 	of_id = of_match_device(fsl_ssi_ids, &pdev->dev);
1319 	if (!of_id || !of_id->data)
1320 		return -EINVAL;
1321 
1322 	ssi_private = devm_kzalloc(&pdev->dev, sizeof(*ssi_private),
1323 			GFP_KERNEL);
1324 	if (!ssi_private) {
1325 		dev_err(&pdev->dev, "could not allocate DAI object\n");
1326 		return -ENOMEM;
1327 	}
1328 
1329 	ssi_private->soc = of_id->data;
1330 
1331 	sprop = of_get_property(np, "fsl,mode", NULL);
1332 	if (sprop) {
1333 		if (!strcmp(sprop, "ac97-slave"))
1334 			ssi_private->dai_fmt = SND_SOC_DAIFMT_AC97;
1335 	}
1336 
1337 	ssi_private->use_dma = !of_property_read_bool(np,
1338 			"fsl,fiq-stream-filter");
1339 
1340 	if (fsl_ssi_is_ac97(ssi_private)) {
1341 		memcpy(&ssi_private->cpu_dai_drv, &fsl_ssi_ac97_dai,
1342 				sizeof(fsl_ssi_ac97_dai));
1343 
1344 		fsl_ac97_data = ssi_private;
1345 
1346 		ret = snd_soc_set_ac97_ops_of_reset(&fsl_ssi_ac97_ops, pdev);
1347 		if (ret) {
1348 			dev_err(&pdev->dev, "could not set AC'97 ops\n");
1349 			return ret;
1350 		}
1351 	} else {
1352 		/* Initialize this copy of the CPU DAI driver structure */
1353 		memcpy(&ssi_private->cpu_dai_drv, &fsl_ssi_dai_template,
1354 		       sizeof(fsl_ssi_dai_template));
1355 	}
1356 	ssi_private->cpu_dai_drv.name = dev_name(&pdev->dev);
1357 
1358 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1359 	iomem = devm_ioremap_resource(&pdev->dev, res);
1360 	if (IS_ERR(iomem))
1361 		return PTR_ERR(iomem);
1362 	ssi_private->ssi_phys = res->start;
1363 
1364 	ret = of_property_match_string(np, "clock-names", "ipg");
1365 	if (ret < 0) {
1366 		ssi_private->has_ipg_clk_name = false;
1367 		ssi_private->regs = devm_regmap_init_mmio(&pdev->dev, iomem,
1368 			&fsl_ssi_regconfig);
1369 	} else {
1370 		ssi_private->has_ipg_clk_name = true;
1371 		ssi_private->regs = devm_regmap_init_mmio_clk(&pdev->dev,
1372 			"ipg", iomem, &fsl_ssi_regconfig);
1373 	}
1374 	if (IS_ERR(ssi_private->regs)) {
1375 		dev_err(&pdev->dev, "Failed to init register map\n");
1376 		return PTR_ERR(ssi_private->regs);
1377 	}
1378 
1379 	ssi_private->irq = platform_get_irq(pdev, 0);
1380 	if (ssi_private->irq < 0) {
1381 		dev_err(&pdev->dev, "no irq for node %s\n", pdev->name);
1382 		return ssi_private->irq;
1383 	}
1384 
1385 	/* Are the RX and the TX clocks locked? */
1386 	if (!of_find_property(np, "fsl,ssi-asynchronous", NULL)) {
1387 		if (!fsl_ssi_is_ac97(ssi_private))
1388 			ssi_private->cpu_dai_drv.symmetric_rates = 1;
1389 
1390 		ssi_private->cpu_dai_drv.symmetric_channels = 1;
1391 		ssi_private->cpu_dai_drv.symmetric_samplebits = 1;
1392 	}
1393 
1394 	/* Determine the FIFO depth. */
1395 	iprop = of_get_property(np, "fsl,fifo-depth", NULL);
1396 	if (iprop)
1397 		ssi_private->fifo_depth = be32_to_cpup(iprop);
1398 	else
1399                 /* Older 8610 DTs didn't have the fifo-depth property */
1400 		ssi_private->fifo_depth = 8;
1401 
1402 	dev_set_drvdata(&pdev->dev, ssi_private);
1403 
1404 	if (ssi_private->soc->imx) {
1405 		ret = fsl_ssi_imx_probe(pdev, ssi_private, iomem);
1406 		if (ret)
1407 			return ret;
1408 	}
1409 
1410 	ret = devm_snd_soc_register_component(&pdev->dev, &fsl_ssi_component,
1411 					      &ssi_private->cpu_dai_drv, 1);
1412 	if (ret) {
1413 		dev_err(&pdev->dev, "failed to register DAI: %d\n", ret);
1414 		goto error_asoc_register;
1415 	}
1416 
1417 	if (ssi_private->use_dma) {
1418 		ret = devm_request_irq(&pdev->dev, ssi_private->irq,
1419 					fsl_ssi_isr, 0, dev_name(&pdev->dev),
1420 					ssi_private);
1421 		if (ret < 0) {
1422 			dev_err(&pdev->dev, "could not claim irq %u\n",
1423 					ssi_private->irq);
1424 			goto error_asoc_register;
1425 		}
1426 	}
1427 
1428 	ret = fsl_ssi_debugfs_create(&ssi_private->dbg_stats, &pdev->dev);
1429 	if (ret)
1430 		goto error_asoc_register;
1431 
1432 	/*
1433 	 * If codec-handle property is missing from SSI node, we assume
1434 	 * that the machine driver uses new binding which does not require
1435 	 * SSI driver to trigger machine driver's probe.
1436 	 */
1437 	if (!of_get_property(np, "codec-handle", NULL))
1438 		goto done;
1439 
1440 	/* Trigger the machine driver's probe function.  The platform driver
1441 	 * name of the machine driver is taken from /compatible property of the
1442 	 * device tree.  We also pass the address of the CPU DAI driver
1443 	 * structure.
1444 	 */
1445 	sprop = of_get_property(of_find_node_by_path("/"), "compatible", NULL);
1446 	/* Sometimes the compatible name has a "fsl," prefix, so we strip it. */
1447 	p = strrchr(sprop, ',');
1448 	if (p)
1449 		sprop = p + 1;
1450 	snprintf(name, sizeof(name), "snd-soc-%s", sprop);
1451 	make_lowercase(name);
1452 
1453 	ssi_private->pdev =
1454 		platform_device_register_data(&pdev->dev, name, 0, NULL, 0);
1455 	if (IS_ERR(ssi_private->pdev)) {
1456 		ret = PTR_ERR(ssi_private->pdev);
1457 		dev_err(&pdev->dev, "failed to register platform: %d\n", ret);
1458 		goto error_sound_card;
1459 	}
1460 
1461 done:
1462 	if (ssi_private->dai_fmt)
1463 		_fsl_ssi_set_dai_fmt(&pdev->dev, ssi_private,
1464 				     ssi_private->dai_fmt);
1465 
1466 	if (fsl_ssi_is_ac97(ssi_private)) {
1467 		u32 ssi_idx;
1468 
1469 		ret = of_property_read_u32(np, "cell-index", &ssi_idx);
1470 		if (ret) {
1471 			dev_err(&pdev->dev, "cannot get SSI index property\n");
1472 			goto error_sound_card;
1473 		}
1474 
1475 		ssi_private->pdev =
1476 			platform_device_register_data(NULL,
1477 					"ac97-codec", ssi_idx, NULL, 0);
1478 		if (IS_ERR(ssi_private->pdev)) {
1479 			ret = PTR_ERR(ssi_private->pdev);
1480 			dev_err(&pdev->dev,
1481 				"failed to register AC97 codec platform: %d\n",
1482 				ret);
1483 			goto error_sound_card;
1484 		}
1485 	}
1486 
1487 	return 0;
1488 
1489 error_sound_card:
1490 	fsl_ssi_debugfs_remove(&ssi_private->dbg_stats);
1491 
1492 error_asoc_register:
1493 	if (ssi_private->soc->imx)
1494 		fsl_ssi_imx_clean(pdev, ssi_private);
1495 
1496 	return ret;
1497 }
1498 
1499 static int fsl_ssi_remove(struct platform_device *pdev)
1500 {
1501 	struct fsl_ssi_private *ssi_private = dev_get_drvdata(&pdev->dev);
1502 
1503 	fsl_ssi_debugfs_remove(&ssi_private->dbg_stats);
1504 
1505 	if (ssi_private->pdev)
1506 		platform_device_unregister(ssi_private->pdev);
1507 
1508 	if (ssi_private->soc->imx)
1509 		fsl_ssi_imx_clean(pdev, ssi_private);
1510 
1511 	if (fsl_ssi_is_ac97(ssi_private))
1512 		snd_soc_set_ac97_ops(NULL);
1513 
1514 	return 0;
1515 }
1516 
1517 static struct platform_driver fsl_ssi_driver = {
1518 	.driver = {
1519 		.name = "fsl-ssi-dai",
1520 		.of_match_table = fsl_ssi_ids,
1521 	},
1522 	.probe = fsl_ssi_probe,
1523 	.remove = fsl_ssi_remove,
1524 };
1525 
1526 module_platform_driver(fsl_ssi_driver);
1527 
1528 MODULE_ALIAS("platform:fsl-ssi-dai");
1529 MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
1530 MODULE_DESCRIPTION("Freescale Synchronous Serial Interface (SSI) ASoC Driver");
1531 MODULE_LICENSE("GPL v2");
1532