xref: /openbmc/linux/sound/soc/fsl/fsl_ssi.c (revision c4ee0af3)
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/of_address.h>
42 #include <linux/of_irq.h>
43 #include <linux/of_platform.h>
44 
45 #include <sound/core.h>
46 #include <sound/pcm.h>
47 #include <sound/pcm_params.h>
48 #include <sound/initval.h>
49 #include <sound/soc.h>
50 #include <sound/dmaengine_pcm.h>
51 
52 #include "fsl_ssi.h"
53 #include "imx-pcm.h"
54 
55 #ifdef PPC
56 #define read_ssi(addr)			 in_be32(addr)
57 #define write_ssi(val, addr)		 out_be32(addr, val)
58 #define write_ssi_mask(addr, clear, set) clrsetbits_be32(addr, clear, set)
59 #else
60 #define read_ssi(addr)			 readl(addr)
61 #define write_ssi(val, addr)		 writel(val, addr)
62 /*
63  * FIXME: Proper locking should be added at write_ssi_mask caller level
64  * to ensure this register read/modify/write sequence is race free.
65  */
66 static inline void write_ssi_mask(u32 __iomem *addr, u32 clear, u32 set)
67 {
68 	u32 val = readl(addr);
69 	val = (val & ~clear) | set;
70 	writel(val, addr);
71 }
72 #endif
73 
74 /**
75  * FSLSSI_I2S_RATES: sample rates supported by the I2S
76  *
77  * This driver currently only supports the SSI running in I2S slave mode,
78  * which means the codec determines the sample rate.  Therefore, we tell
79  * ALSA that we support all rates and let the codec driver decide what rates
80  * are really supported.
81  */
82 #define FSLSSI_I2S_RATES (SNDRV_PCM_RATE_5512 | SNDRV_PCM_RATE_8000_192000 | \
83 			  SNDRV_PCM_RATE_CONTINUOUS)
84 
85 /**
86  * FSLSSI_I2S_FORMATS: audio formats supported by the SSI
87  *
88  * This driver currently only supports the SSI running in I2S slave mode.
89  *
90  * The SSI has a limitation in that the samples must be in the same byte
91  * order as the host CPU.  This is because when multiple bytes are written
92  * to the STX register, the bytes and bits must be written in the same
93  * order.  The STX is a shift register, so all the bits need to be aligned
94  * (bit-endianness must match byte-endianness).  Processors typically write
95  * the bits within a byte in the same order that the bytes of a word are
96  * written in.  So if the host CPU is big-endian, then only big-endian
97  * samples will be written to STX properly.
98  */
99 #ifdef __BIG_ENDIAN
100 #define FSLSSI_I2S_FORMATS (SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_BE | \
101 	 SNDRV_PCM_FMTBIT_S18_3BE | SNDRV_PCM_FMTBIT_S20_3BE | \
102 	 SNDRV_PCM_FMTBIT_S24_3BE | SNDRV_PCM_FMTBIT_S24_BE)
103 #else
104 #define FSLSSI_I2S_FORMATS (SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_LE | \
105 	 SNDRV_PCM_FMTBIT_S18_3LE | SNDRV_PCM_FMTBIT_S20_3LE | \
106 	 SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_LE)
107 #endif
108 
109 /* SIER bitflag of interrupts to enable */
110 #define SIER_FLAGS (CCSR_SSI_SIER_TFRC_EN | CCSR_SSI_SIER_TDMAE | \
111 		    CCSR_SSI_SIER_TIE | CCSR_SSI_SIER_TUE0_EN | \
112 		    CCSR_SSI_SIER_TUE1_EN | CCSR_SSI_SIER_RFRC_EN | \
113 		    CCSR_SSI_SIER_RDMAE | CCSR_SSI_SIER_RIE | \
114 		    CCSR_SSI_SIER_ROE0_EN | CCSR_SSI_SIER_ROE1_EN)
115 
116 /**
117  * fsl_ssi_private: per-SSI private data
118  *
119  * @ssi: pointer to the SSI's registers
120  * @ssi_phys: physical address of the SSI registers
121  * @irq: IRQ of this SSI
122  * @first_stream: pointer to the stream that was opened first
123  * @second_stream: pointer to second stream
124  * @playback: the number of playback streams opened
125  * @capture: the number of capture streams opened
126  * @cpu_dai: the CPU DAI for this device
127  * @dev_attr: the sysfs device attribute structure
128  * @stats: SSI statistics
129  * @name: name for this device
130  */
131 struct fsl_ssi_private {
132 	struct ccsr_ssi __iomem *ssi;
133 	dma_addr_t ssi_phys;
134 	unsigned int irq;
135 	struct snd_pcm_substream *first_stream;
136 	struct snd_pcm_substream *second_stream;
137 	unsigned int fifo_depth;
138 	struct snd_soc_dai_driver cpu_dai_drv;
139 	struct device_attribute dev_attr;
140 	struct platform_device *pdev;
141 
142 	bool new_binding;
143 	bool ssi_on_imx;
144 	bool imx_ac97;
145 	bool use_dma;
146 	struct clk *clk;
147 	struct snd_dmaengine_dai_dma_data dma_params_tx;
148 	struct snd_dmaengine_dai_dma_data dma_params_rx;
149 	struct imx_dma_data filter_data_tx;
150 	struct imx_dma_data filter_data_rx;
151 	struct imx_pcm_fiq_params fiq_params;
152 
153 	struct {
154 		unsigned int rfrc;
155 		unsigned int tfrc;
156 		unsigned int cmdau;
157 		unsigned int cmddu;
158 		unsigned int rxt;
159 		unsigned int rdr1;
160 		unsigned int rdr0;
161 		unsigned int tde1;
162 		unsigned int tde0;
163 		unsigned int roe1;
164 		unsigned int roe0;
165 		unsigned int tue1;
166 		unsigned int tue0;
167 		unsigned int tfs;
168 		unsigned int rfs;
169 		unsigned int tls;
170 		unsigned int rls;
171 		unsigned int rff1;
172 		unsigned int rff0;
173 		unsigned int tfe1;
174 		unsigned int tfe0;
175 	} stats;
176 
177 	char name[1];
178 };
179 
180 /**
181  * fsl_ssi_isr: SSI interrupt handler
182  *
183  * Although it's possible to use the interrupt handler to send and receive
184  * data to/from the SSI, we use the DMA instead.  Programming is more
185  * complicated, but the performance is much better.
186  *
187  * This interrupt handler is used only to gather statistics.
188  *
189  * @irq: IRQ of the SSI device
190  * @dev_id: pointer to the ssi_private structure for this SSI device
191  */
192 static irqreturn_t fsl_ssi_isr(int irq, void *dev_id)
193 {
194 	struct fsl_ssi_private *ssi_private = dev_id;
195 	struct ccsr_ssi __iomem *ssi = ssi_private->ssi;
196 	irqreturn_t ret = IRQ_NONE;
197 	__be32 sisr;
198 	__be32 sisr2 = 0;
199 
200 	/* We got an interrupt, so read the status register to see what we
201 	   were interrupted for.  We mask it with the Interrupt Enable register
202 	   so that we only check for events that we're interested in.
203 	 */
204 	sisr = read_ssi(&ssi->sisr) & SIER_FLAGS;
205 
206 	if (sisr & CCSR_SSI_SISR_RFRC) {
207 		ssi_private->stats.rfrc++;
208 		sisr2 |= CCSR_SSI_SISR_RFRC;
209 		ret = IRQ_HANDLED;
210 	}
211 
212 	if (sisr & CCSR_SSI_SISR_TFRC) {
213 		ssi_private->stats.tfrc++;
214 		sisr2 |= CCSR_SSI_SISR_TFRC;
215 		ret = IRQ_HANDLED;
216 	}
217 
218 	if (sisr & CCSR_SSI_SISR_CMDAU) {
219 		ssi_private->stats.cmdau++;
220 		ret = IRQ_HANDLED;
221 	}
222 
223 	if (sisr & CCSR_SSI_SISR_CMDDU) {
224 		ssi_private->stats.cmddu++;
225 		ret = IRQ_HANDLED;
226 	}
227 
228 	if (sisr & CCSR_SSI_SISR_RXT) {
229 		ssi_private->stats.rxt++;
230 		ret = IRQ_HANDLED;
231 	}
232 
233 	if (sisr & CCSR_SSI_SISR_RDR1) {
234 		ssi_private->stats.rdr1++;
235 		ret = IRQ_HANDLED;
236 	}
237 
238 	if (sisr & CCSR_SSI_SISR_RDR0) {
239 		ssi_private->stats.rdr0++;
240 		ret = IRQ_HANDLED;
241 	}
242 
243 	if (sisr & CCSR_SSI_SISR_TDE1) {
244 		ssi_private->stats.tde1++;
245 		ret = IRQ_HANDLED;
246 	}
247 
248 	if (sisr & CCSR_SSI_SISR_TDE0) {
249 		ssi_private->stats.tde0++;
250 		ret = IRQ_HANDLED;
251 	}
252 
253 	if (sisr & CCSR_SSI_SISR_ROE1) {
254 		ssi_private->stats.roe1++;
255 		sisr2 |= CCSR_SSI_SISR_ROE1;
256 		ret = IRQ_HANDLED;
257 	}
258 
259 	if (sisr & CCSR_SSI_SISR_ROE0) {
260 		ssi_private->stats.roe0++;
261 		sisr2 |= CCSR_SSI_SISR_ROE0;
262 		ret = IRQ_HANDLED;
263 	}
264 
265 	if (sisr & CCSR_SSI_SISR_TUE1) {
266 		ssi_private->stats.tue1++;
267 		sisr2 |= CCSR_SSI_SISR_TUE1;
268 		ret = IRQ_HANDLED;
269 	}
270 
271 	if (sisr & CCSR_SSI_SISR_TUE0) {
272 		ssi_private->stats.tue0++;
273 		sisr2 |= CCSR_SSI_SISR_TUE0;
274 		ret = IRQ_HANDLED;
275 	}
276 
277 	if (sisr & CCSR_SSI_SISR_TFS) {
278 		ssi_private->stats.tfs++;
279 		ret = IRQ_HANDLED;
280 	}
281 
282 	if (sisr & CCSR_SSI_SISR_RFS) {
283 		ssi_private->stats.rfs++;
284 		ret = IRQ_HANDLED;
285 	}
286 
287 	if (sisr & CCSR_SSI_SISR_TLS) {
288 		ssi_private->stats.tls++;
289 		ret = IRQ_HANDLED;
290 	}
291 
292 	if (sisr & CCSR_SSI_SISR_RLS) {
293 		ssi_private->stats.rls++;
294 		ret = IRQ_HANDLED;
295 	}
296 
297 	if (sisr & CCSR_SSI_SISR_RFF1) {
298 		ssi_private->stats.rff1++;
299 		ret = IRQ_HANDLED;
300 	}
301 
302 	if (sisr & CCSR_SSI_SISR_RFF0) {
303 		ssi_private->stats.rff0++;
304 		ret = IRQ_HANDLED;
305 	}
306 
307 	if (sisr & CCSR_SSI_SISR_TFE1) {
308 		ssi_private->stats.tfe1++;
309 		ret = IRQ_HANDLED;
310 	}
311 
312 	if (sisr & CCSR_SSI_SISR_TFE0) {
313 		ssi_private->stats.tfe0++;
314 		ret = IRQ_HANDLED;
315 	}
316 
317 	/* Clear the bits that we set */
318 	if (sisr2)
319 		write_ssi(sisr2, &ssi->sisr);
320 
321 	return ret;
322 }
323 
324 static int fsl_ssi_setup(struct fsl_ssi_private *ssi_private)
325 {
326 	struct ccsr_ssi __iomem *ssi = ssi_private->ssi;
327 	u8 i2s_mode;
328 	u8 wm;
329 	int synchronous = ssi_private->cpu_dai_drv.symmetric_rates;
330 
331 	if (ssi_private->imx_ac97)
332 		i2s_mode = CCSR_SSI_SCR_I2S_MODE_NORMAL | CCSR_SSI_SCR_NET;
333 	else
334 		i2s_mode = CCSR_SSI_SCR_I2S_MODE_SLAVE;
335 
336 	/*
337 	 * Section 16.5 of the MPC8610 reference manual says that the SSI needs
338 	 * to be disabled before updating the registers we set here.
339 	 */
340 	write_ssi_mask(&ssi->scr, CCSR_SSI_SCR_SSIEN, 0);
341 
342 	/*
343 	 * Program the SSI into I2S Slave Non-Network Synchronous mode. Also
344 	 * enable the transmit and receive FIFO.
345 	 *
346 	 * FIXME: Little-endian samples require a different shift dir
347 	 */
348 	write_ssi_mask(&ssi->scr,
349 		CCSR_SSI_SCR_I2S_MODE_MASK | CCSR_SSI_SCR_SYN,
350 		CCSR_SSI_SCR_TFR_CLK_DIS |
351 		i2s_mode |
352 		(synchronous ? CCSR_SSI_SCR_SYN : 0));
353 
354 	write_ssi(CCSR_SSI_STCR_TXBIT0 | CCSR_SSI_STCR_TFEN0 |
355 		 CCSR_SSI_STCR_TFSI | CCSR_SSI_STCR_TEFS |
356 		 CCSR_SSI_STCR_TSCKP, &ssi->stcr);
357 
358 	write_ssi(CCSR_SSI_SRCR_RXBIT0 | CCSR_SSI_SRCR_RFEN0 |
359 		 CCSR_SSI_SRCR_RFSI | CCSR_SSI_SRCR_REFS |
360 		 CCSR_SSI_SRCR_RSCKP, &ssi->srcr);
361 	/*
362 	 * The DC and PM bits are only used if the SSI is the clock master.
363 	 */
364 
365 	/*
366 	 * Set the watermark for transmit FIFI 0 and receive FIFO 0. We don't
367 	 * use FIFO 1. We program the transmit water to signal a DMA transfer
368 	 * if there are only two (or fewer) elements left in the FIFO. Two
369 	 * elements equals one frame (left channel, right channel). This value,
370 	 * however, depends on the depth of the transmit buffer.
371 	 *
372 	 * We set the watermark on the same level as the DMA burstsize.  For
373 	 * fiq it is probably better to use the biggest possible watermark
374 	 * size.
375 	 */
376 	if (ssi_private->use_dma)
377 		wm = ssi_private->fifo_depth - 2;
378 	else
379 		wm = ssi_private->fifo_depth;
380 
381 	write_ssi(CCSR_SSI_SFCSR_TFWM0(wm) | CCSR_SSI_SFCSR_RFWM0(wm) |
382 		CCSR_SSI_SFCSR_TFWM1(wm) | CCSR_SSI_SFCSR_RFWM1(wm),
383 		&ssi->sfcsr);
384 
385 	/*
386 	 * For ac97 interrupts are enabled with the startup of the substream
387 	 * because it is also running without an active substream. Normally SSI
388 	 * is only enabled when there is a substream.
389 	 */
390 	if (ssi_private->imx_ac97) {
391 		/*
392 		 * Setup the clock control register
393 		 */
394 		write_ssi(CCSR_SSI_SxCCR_WL(17) | CCSR_SSI_SxCCR_DC(13),
395 				&ssi->stccr);
396 		write_ssi(CCSR_SSI_SxCCR_WL(17) | CCSR_SSI_SxCCR_DC(13),
397 				&ssi->srccr);
398 
399 		/*
400 		 * Enable AC97 mode and startup the SSI
401 		 */
402 		write_ssi(CCSR_SSI_SACNT_AC97EN | CCSR_SSI_SACNT_FV,
403 				&ssi->sacnt);
404 		write_ssi(0xff, &ssi->saccdis);
405 		write_ssi(0x300, &ssi->saccen);
406 
407 		/*
408 		 * Enable SSI, Transmit and Receive
409 		 */
410 		write_ssi_mask(&ssi->scr, 0, CCSR_SSI_SCR_SSIEN |
411 				CCSR_SSI_SCR_TE | CCSR_SSI_SCR_RE);
412 
413 		write_ssi(CCSR_SSI_SOR_WAIT(3), &ssi->sor);
414 	}
415 
416 	return 0;
417 }
418 
419 
420 /**
421  * fsl_ssi_startup: create a new substream
422  *
423  * This is the first function called when a stream is opened.
424  *
425  * If this is the first stream open, then grab the IRQ and program most of
426  * the SSI registers.
427  */
428 static int fsl_ssi_startup(struct snd_pcm_substream *substream,
429 			   struct snd_soc_dai *dai)
430 {
431 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
432 	struct fsl_ssi_private *ssi_private =
433 		snd_soc_dai_get_drvdata(rtd->cpu_dai);
434 	int synchronous = ssi_private->cpu_dai_drv.symmetric_rates;
435 
436 	/*
437 	 * If this is the first stream opened, then request the IRQ
438 	 * and initialize the SSI registers.
439 	 */
440 	if (!ssi_private->first_stream) {
441 		ssi_private->first_stream = substream;
442 
443 		/*
444 		 * fsl_ssi_setup was already called by ac97_init earlier if
445 		 * the driver is in ac97 mode.
446 		 */
447 		if (!ssi_private->imx_ac97)
448 			fsl_ssi_setup(ssi_private);
449 	} else {
450 		if (synchronous) {
451 			struct snd_pcm_runtime *first_runtime =
452 				ssi_private->first_stream->runtime;
453 			/*
454 			 * This is the second stream open, and we're in
455 			 * synchronous mode, so we need to impose sample
456 			 * sample size constraints. This is because STCCR is
457 			 * used for playback and capture in synchronous mode,
458 			 * so there's no way to specify different word
459 			 * lengths.
460 			 *
461 			 * Note that this can cause a race condition if the
462 			 * second stream is opened before the first stream is
463 			 * fully initialized.  We provide some protection by
464 			 * checking to make sure the first stream is
465 			 * initialized, but it's not perfect.  ALSA sometimes
466 			 * re-initializes the driver with a different sample
467 			 * rate or size.  If the second stream is opened
468 			 * before the first stream has received its final
469 			 * parameters, then the second stream may be
470 			 * constrained to the wrong sample rate or size.
471 			 */
472 			if (first_runtime->sample_bits) {
473 				snd_pcm_hw_constraint_minmax(substream->runtime,
474 						SNDRV_PCM_HW_PARAM_SAMPLE_BITS,
475 				first_runtime->sample_bits,
476 				first_runtime->sample_bits);
477 			}
478 		}
479 
480 		ssi_private->second_stream = substream;
481 	}
482 
483 	return 0;
484 }
485 
486 /**
487  * fsl_ssi_hw_params - program the sample size
488  *
489  * Most of the SSI registers have been programmed in the startup function,
490  * but the word length must be programmed here.  Unfortunately, programming
491  * the SxCCR.WL bits requires the SSI to be temporarily disabled.  This can
492  * cause a problem with supporting simultaneous playback and capture.  If
493  * the SSI is already playing a stream, then that stream may be temporarily
494  * stopped when you start capture.
495  *
496  * Note: The SxCCR.DC and SxCCR.PM bits are only used if the SSI is the
497  * clock master.
498  */
499 static int fsl_ssi_hw_params(struct snd_pcm_substream *substream,
500 	struct snd_pcm_hw_params *hw_params, struct snd_soc_dai *cpu_dai)
501 {
502 	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(cpu_dai);
503 	struct ccsr_ssi __iomem *ssi = ssi_private->ssi;
504 	unsigned int sample_size =
505 		snd_pcm_format_width(params_format(hw_params));
506 	u32 wl = CCSR_SSI_SxCCR_WL(sample_size);
507 	int enabled = read_ssi(&ssi->scr) & CCSR_SSI_SCR_SSIEN;
508 
509 	/*
510 	 * If we're in synchronous mode, and the SSI is already enabled,
511 	 * then STCCR is already set properly.
512 	 */
513 	if (enabled && ssi_private->cpu_dai_drv.symmetric_rates)
514 		return 0;
515 
516 	/*
517 	 * FIXME: The documentation says that SxCCR[WL] should not be
518 	 * modified while the SSI is enabled.  The only time this can
519 	 * happen is if we're trying to do simultaneous playback and
520 	 * capture in asynchronous mode.  Unfortunately, I have been enable
521 	 * to get that to work at all on the P1022DS.  Therefore, we don't
522 	 * bother to disable/enable the SSI when setting SxCCR[WL], because
523 	 * the SSI will stop anyway.  Maybe one day, this will get fixed.
524 	 */
525 
526 	/* In synchronous mode, the SSI uses STCCR for capture */
527 	if ((substream->stream == SNDRV_PCM_STREAM_PLAYBACK) ||
528 	    ssi_private->cpu_dai_drv.symmetric_rates)
529 		write_ssi_mask(&ssi->stccr, CCSR_SSI_SxCCR_WL_MASK, wl);
530 	else
531 		write_ssi_mask(&ssi->srccr, CCSR_SSI_SxCCR_WL_MASK, wl);
532 
533 	return 0;
534 }
535 
536 /**
537  * fsl_ssi_trigger: start and stop the DMA transfer.
538  *
539  * This function is called by ALSA to start, stop, pause, and resume the DMA
540  * transfer of data.
541  *
542  * The DMA channel is in external master start and pause mode, which
543  * means the SSI completely controls the flow of data.
544  */
545 static int fsl_ssi_trigger(struct snd_pcm_substream *substream, int cmd,
546 			   struct snd_soc_dai *dai)
547 {
548 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
549 	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(rtd->cpu_dai);
550 	struct ccsr_ssi __iomem *ssi = ssi_private->ssi;
551 	unsigned int sier_bits;
552 
553 	/*
554 	 *  Enable only the interrupts and DMA requests
555 	 *  that are needed for the channel. As the fiq
556 	 *  is polling for this bits, we have to ensure
557 	 *  that this are aligned with the preallocated
558 	 *  buffers
559 	 */
560 
561 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
562 		if (ssi_private->use_dma)
563 			sier_bits = SIER_FLAGS;
564 		else
565 			sier_bits = CCSR_SSI_SIER_TIE | CCSR_SSI_SIER_TFE0_EN;
566 	} else {
567 		if (ssi_private->use_dma)
568 			sier_bits = SIER_FLAGS;
569 		else
570 			sier_bits = CCSR_SSI_SIER_RIE | CCSR_SSI_SIER_RFF0_EN;
571 	}
572 
573 	switch (cmd) {
574 	case SNDRV_PCM_TRIGGER_START:
575 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
576 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
577 			write_ssi_mask(&ssi->scr, 0,
578 				CCSR_SSI_SCR_SSIEN | CCSR_SSI_SCR_TE);
579 		else
580 			write_ssi_mask(&ssi->scr, 0,
581 				CCSR_SSI_SCR_SSIEN | CCSR_SSI_SCR_RE);
582 		break;
583 
584 	case SNDRV_PCM_TRIGGER_STOP:
585 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
586 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
587 			write_ssi_mask(&ssi->scr, CCSR_SSI_SCR_TE, 0);
588 		else
589 			write_ssi_mask(&ssi->scr, CCSR_SSI_SCR_RE, 0);
590 
591 		if (!ssi_private->imx_ac97 && (read_ssi(&ssi->scr) &
592 					(CCSR_SSI_SCR_TE | CCSR_SSI_SCR_RE)) == 0)
593 			write_ssi_mask(&ssi->scr, CCSR_SSI_SCR_SSIEN, 0);
594 		break;
595 
596 	default:
597 		return -EINVAL;
598 	}
599 
600 	write_ssi(sier_bits, &ssi->sier);
601 
602 	return 0;
603 }
604 
605 /**
606  * fsl_ssi_shutdown: shutdown the SSI
607  *
608  * Shutdown the SSI if there are no other substreams open.
609  */
610 static void fsl_ssi_shutdown(struct snd_pcm_substream *substream,
611 			     struct snd_soc_dai *dai)
612 {
613 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
614 	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(rtd->cpu_dai);
615 
616 	if (ssi_private->first_stream == substream)
617 		ssi_private->first_stream = ssi_private->second_stream;
618 
619 	ssi_private->second_stream = NULL;
620 }
621 
622 static int fsl_ssi_dai_probe(struct snd_soc_dai *dai)
623 {
624 	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(dai);
625 
626 	if (ssi_private->ssi_on_imx && ssi_private->use_dma) {
627 		dai->playback_dma_data = &ssi_private->dma_params_tx;
628 		dai->capture_dma_data = &ssi_private->dma_params_rx;
629 	}
630 
631 	return 0;
632 }
633 
634 static const struct snd_soc_dai_ops fsl_ssi_dai_ops = {
635 	.startup	= fsl_ssi_startup,
636 	.hw_params	= fsl_ssi_hw_params,
637 	.shutdown	= fsl_ssi_shutdown,
638 	.trigger	= fsl_ssi_trigger,
639 };
640 
641 /* Template for the CPU dai driver structure */
642 static struct snd_soc_dai_driver fsl_ssi_dai_template = {
643 	.probe = fsl_ssi_dai_probe,
644 	.playback = {
645 		/* The SSI does not support monaural audio. */
646 		.channels_min = 2,
647 		.channels_max = 2,
648 		.rates = FSLSSI_I2S_RATES,
649 		.formats = FSLSSI_I2S_FORMATS,
650 	},
651 	.capture = {
652 		.channels_min = 2,
653 		.channels_max = 2,
654 		.rates = FSLSSI_I2S_RATES,
655 		.formats = FSLSSI_I2S_FORMATS,
656 	},
657 	.ops = &fsl_ssi_dai_ops,
658 };
659 
660 static const struct snd_soc_component_driver fsl_ssi_component = {
661 	.name		= "fsl-ssi",
662 };
663 
664 /**
665  * fsl_ssi_ac97_trigger: start and stop the AC97 receive/transmit.
666  *
667  * This function is called by ALSA to start, stop, pause, and resume the
668  * transfer of data.
669  */
670 static int fsl_ssi_ac97_trigger(struct snd_pcm_substream *substream, int cmd,
671 			   struct snd_soc_dai *dai)
672 {
673 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
674 	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(
675 			rtd->cpu_dai);
676 	struct ccsr_ssi __iomem *ssi = ssi_private->ssi;
677 
678 	switch (cmd) {
679 	case SNDRV_PCM_TRIGGER_START:
680 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
681 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
682 			write_ssi_mask(&ssi->sier, 0, CCSR_SSI_SIER_TIE |
683 					CCSR_SSI_SIER_TFE0_EN);
684 		else
685 			write_ssi_mask(&ssi->sier, 0, CCSR_SSI_SIER_RIE |
686 					CCSR_SSI_SIER_RFF0_EN);
687 		break;
688 
689 	case SNDRV_PCM_TRIGGER_STOP:
690 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
691 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
692 			write_ssi_mask(&ssi->sier, CCSR_SSI_SIER_TIE |
693 					CCSR_SSI_SIER_TFE0_EN, 0);
694 		else
695 			write_ssi_mask(&ssi->sier, CCSR_SSI_SIER_RIE |
696 					CCSR_SSI_SIER_RFF0_EN, 0);
697 		break;
698 
699 	default:
700 		return -EINVAL;
701 	}
702 
703 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
704 		write_ssi(CCSR_SSI_SOR_TX_CLR, &ssi->sor);
705 	else
706 		write_ssi(CCSR_SSI_SOR_RX_CLR, &ssi->sor);
707 
708 	return 0;
709 }
710 
711 static const struct snd_soc_dai_ops fsl_ssi_ac97_dai_ops = {
712 	.startup	= fsl_ssi_startup,
713 	.shutdown	= fsl_ssi_shutdown,
714 	.trigger	= fsl_ssi_ac97_trigger,
715 };
716 
717 static struct snd_soc_dai_driver fsl_ssi_ac97_dai = {
718 	.ac97_control = 1,
719 	.playback = {
720 		.stream_name = "AC97 Playback",
721 		.channels_min = 2,
722 		.channels_max = 2,
723 		.rates = SNDRV_PCM_RATE_8000_48000,
724 		.formats = SNDRV_PCM_FMTBIT_S16_LE,
725 	},
726 	.capture = {
727 		.stream_name = "AC97 Capture",
728 		.channels_min = 2,
729 		.channels_max = 2,
730 		.rates = SNDRV_PCM_RATE_48000,
731 		.formats = SNDRV_PCM_FMTBIT_S16_LE,
732 	},
733 	.ops = &fsl_ssi_ac97_dai_ops,
734 };
735 
736 
737 static struct fsl_ssi_private *fsl_ac97_data;
738 
739 static void fsl_ssi_ac97_init(void)
740 {
741 	fsl_ssi_setup(fsl_ac97_data);
742 }
743 
744 static void fsl_ssi_ac97_write(struct snd_ac97 *ac97, unsigned short reg,
745 		unsigned short val)
746 {
747 	struct ccsr_ssi *ssi = fsl_ac97_data->ssi;
748 	unsigned int lreg;
749 	unsigned int lval;
750 
751 	if (reg > 0x7f)
752 		return;
753 
754 
755 	lreg = reg <<  12;
756 	write_ssi(lreg, &ssi->sacadd);
757 
758 	lval = val << 4;
759 	write_ssi(lval , &ssi->sacdat);
760 
761 	write_ssi_mask(&ssi->sacnt, CCSR_SSI_SACNT_RDWR_MASK,
762 			CCSR_SSI_SACNT_WR);
763 	udelay(100);
764 }
765 
766 static unsigned short fsl_ssi_ac97_read(struct snd_ac97 *ac97,
767 		unsigned short reg)
768 {
769 	struct ccsr_ssi *ssi = fsl_ac97_data->ssi;
770 
771 	unsigned short val = -1;
772 	unsigned int lreg;
773 
774 	lreg = (reg & 0x7f) <<  12;
775 	write_ssi(lreg, &ssi->sacadd);
776 	write_ssi_mask(&ssi->sacnt, CCSR_SSI_SACNT_RDWR_MASK,
777 			CCSR_SSI_SACNT_RD);
778 
779 	udelay(100);
780 
781 	val = (read_ssi(&ssi->sacdat) >> 4) & 0xffff;
782 
783 	return val;
784 }
785 
786 static struct snd_ac97_bus_ops fsl_ssi_ac97_ops = {
787 	.read		= fsl_ssi_ac97_read,
788 	.write		= fsl_ssi_ac97_write,
789 };
790 
791 /* Show the statistics of a flag only if its interrupt is enabled.  The
792  * compiler will optimze this code to a no-op if the interrupt is not
793  * enabled.
794  */
795 #define SIER_SHOW(flag, name) \
796 	do { \
797 		if (SIER_FLAGS & CCSR_SSI_SIER_##flag) \
798 			length += sprintf(buf + length, #name "=%u\n", \
799 				ssi_private->stats.name); \
800 	} while (0)
801 
802 
803 /**
804  * fsl_sysfs_ssi_show: display SSI statistics
805  *
806  * Display the statistics for the current SSI device.  To avoid confusion,
807  * we only show those counts that are enabled.
808  */
809 static ssize_t fsl_sysfs_ssi_show(struct device *dev,
810 	struct device_attribute *attr, char *buf)
811 {
812 	struct fsl_ssi_private *ssi_private =
813 		container_of(attr, struct fsl_ssi_private, dev_attr);
814 	ssize_t length = 0;
815 
816 	SIER_SHOW(RFRC_EN, rfrc);
817 	SIER_SHOW(TFRC_EN, tfrc);
818 	SIER_SHOW(CMDAU_EN, cmdau);
819 	SIER_SHOW(CMDDU_EN, cmddu);
820 	SIER_SHOW(RXT_EN, rxt);
821 	SIER_SHOW(RDR1_EN, rdr1);
822 	SIER_SHOW(RDR0_EN, rdr0);
823 	SIER_SHOW(TDE1_EN, tde1);
824 	SIER_SHOW(TDE0_EN, tde0);
825 	SIER_SHOW(ROE1_EN, roe1);
826 	SIER_SHOW(ROE0_EN, roe0);
827 	SIER_SHOW(TUE1_EN, tue1);
828 	SIER_SHOW(TUE0_EN, tue0);
829 	SIER_SHOW(TFS_EN, tfs);
830 	SIER_SHOW(RFS_EN, rfs);
831 	SIER_SHOW(TLS_EN, tls);
832 	SIER_SHOW(RLS_EN, rls);
833 	SIER_SHOW(RFF1_EN, rff1);
834 	SIER_SHOW(RFF0_EN, rff0);
835 	SIER_SHOW(TFE1_EN, tfe1);
836 	SIER_SHOW(TFE0_EN, tfe0);
837 
838 	return length;
839 }
840 
841 /**
842  * Make every character in a string lower-case
843  */
844 static void make_lowercase(char *s)
845 {
846 	char *p = s;
847 	char c;
848 
849 	while ((c = *p)) {
850 		if ((c >= 'A') && (c <= 'Z'))
851 			*p = c + ('a' - 'A');
852 		p++;
853 	}
854 }
855 
856 static int fsl_ssi_probe(struct platform_device *pdev)
857 {
858 	struct fsl_ssi_private *ssi_private;
859 	int ret = 0;
860 	struct device_attribute *dev_attr = NULL;
861 	struct device_node *np = pdev->dev.of_node;
862 	const char *p, *sprop;
863 	const uint32_t *iprop;
864 	struct resource res;
865 	char name[64];
866 	bool shared;
867 	bool ac97 = false;
868 
869 	/* SSIs that are not connected on the board should have a
870 	 *      status = "disabled"
871 	 * property in their device tree nodes.
872 	 */
873 	if (!of_device_is_available(np))
874 		return -ENODEV;
875 
876 	/* We only support the SSI in "I2S Slave" mode */
877 	sprop = of_get_property(np, "fsl,mode", NULL);
878 	if (!sprop) {
879 		dev_err(&pdev->dev, "fsl,mode property is necessary\n");
880 		return -EINVAL;
881 	}
882 	if (!strcmp(sprop, "ac97-slave")) {
883 		ac97 = true;
884 	} else if (strcmp(sprop, "i2s-slave")) {
885 		dev_notice(&pdev->dev, "mode %s is unsupported\n", sprop);
886 		return -ENODEV;
887 	}
888 
889 	/* The DAI name is the last part of the full name of the node. */
890 	p = strrchr(np->full_name, '/') + 1;
891 	ssi_private = devm_kzalloc(&pdev->dev, sizeof(*ssi_private) + strlen(p),
892 			      GFP_KERNEL);
893 	if (!ssi_private) {
894 		dev_err(&pdev->dev, "could not allocate DAI object\n");
895 		return -ENOMEM;
896 	}
897 
898 	strcpy(ssi_private->name, p);
899 
900 	ssi_private->use_dma = !of_property_read_bool(np,
901 			"fsl,fiq-stream-filter");
902 
903 	if (ac97) {
904 		memcpy(&ssi_private->cpu_dai_drv, &fsl_ssi_ac97_dai,
905 				sizeof(fsl_ssi_ac97_dai));
906 
907 		fsl_ac97_data = ssi_private;
908 		ssi_private->imx_ac97 = true;
909 
910 		snd_soc_set_ac97_ops_of_reset(&fsl_ssi_ac97_ops, pdev);
911 	} else {
912 		/* Initialize this copy of the CPU DAI driver structure */
913 		memcpy(&ssi_private->cpu_dai_drv, &fsl_ssi_dai_template,
914 		       sizeof(fsl_ssi_dai_template));
915 	}
916 	ssi_private->cpu_dai_drv.name = ssi_private->name;
917 
918 	/* Get the addresses and IRQ */
919 	ret = of_address_to_resource(np, 0, &res);
920 	if (ret) {
921 		dev_err(&pdev->dev, "could not determine device resources\n");
922 		return ret;
923 	}
924 	ssi_private->ssi = of_iomap(np, 0);
925 	if (!ssi_private->ssi) {
926 		dev_err(&pdev->dev, "could not map device resources\n");
927 		return -ENOMEM;
928 	}
929 	ssi_private->ssi_phys = res.start;
930 
931 	ssi_private->irq = irq_of_parse_and_map(np, 0);
932 	if (!ssi_private->irq) {
933 		dev_err(&pdev->dev, "no irq for node %s\n", np->full_name);
934 		return -ENXIO;
935 	}
936 
937 	/* Are the RX and the TX clocks locked? */
938 	if (!of_find_property(np, "fsl,ssi-asynchronous", NULL))
939 		ssi_private->cpu_dai_drv.symmetric_rates = 1;
940 
941 	/* Determine the FIFO depth. */
942 	iprop = of_get_property(np, "fsl,fifo-depth", NULL);
943 	if (iprop)
944 		ssi_private->fifo_depth = be32_to_cpup(iprop);
945 	else
946                 /* Older 8610 DTs didn't have the fifo-depth property */
947 		ssi_private->fifo_depth = 8;
948 
949 	if (of_device_is_compatible(pdev->dev.of_node, "fsl,imx21-ssi")) {
950 		u32 dma_events[2];
951 		ssi_private->ssi_on_imx = true;
952 
953 		ssi_private->clk = devm_clk_get(&pdev->dev, NULL);
954 		if (IS_ERR(ssi_private->clk)) {
955 			ret = PTR_ERR(ssi_private->clk);
956 			dev_err(&pdev->dev, "could not get clock: %d\n", ret);
957 			goto error_irqmap;
958 		}
959 		ret = clk_prepare_enable(ssi_private->clk);
960 		if (ret) {
961 			dev_err(&pdev->dev, "clk_prepare_enable failed: %d\n",
962 				ret);
963 			goto error_irqmap;
964 		}
965 
966 		/*
967 		 * We have burstsize be "fifo_depth - 2" to match the SSI
968 		 * watermark setting in fsl_ssi_startup().
969 		 */
970 		ssi_private->dma_params_tx.maxburst =
971 			ssi_private->fifo_depth - 2;
972 		ssi_private->dma_params_rx.maxburst =
973 			ssi_private->fifo_depth - 2;
974 		ssi_private->dma_params_tx.addr =
975 			ssi_private->ssi_phys + offsetof(struct ccsr_ssi, stx0);
976 		ssi_private->dma_params_rx.addr =
977 			ssi_private->ssi_phys + offsetof(struct ccsr_ssi, srx0);
978 		ssi_private->dma_params_tx.filter_data =
979 			&ssi_private->filter_data_tx;
980 		ssi_private->dma_params_rx.filter_data =
981 			&ssi_private->filter_data_rx;
982 		if (!of_property_read_bool(pdev->dev.of_node, "dmas") &&
983 				ssi_private->use_dma) {
984 			/*
985 			 * FIXME: This is a temporary solution until all
986 			 * necessary dma drivers support the generic dma
987 			 * bindings.
988 			 */
989 			ret = of_property_read_u32_array(pdev->dev.of_node,
990 					"fsl,ssi-dma-events", dma_events, 2);
991 			if (ret && ssi_private->use_dma) {
992 				dev_err(&pdev->dev, "could not get dma events but fsl-ssi is configured to use DMA\n");
993 				goto error_clk;
994 			}
995 		}
996 
997 		shared = of_device_is_compatible(of_get_parent(np),
998 			    "fsl,spba-bus");
999 
1000 		imx_pcm_dma_params_init_data(&ssi_private->filter_data_tx,
1001 			dma_events[0], shared ? IMX_DMATYPE_SSI_SP : IMX_DMATYPE_SSI);
1002 		imx_pcm_dma_params_init_data(&ssi_private->filter_data_rx,
1003 			dma_events[1], shared ? IMX_DMATYPE_SSI_SP : IMX_DMATYPE_SSI);
1004 	} else if (ssi_private->use_dma) {
1005 		/* The 'name' should not have any slashes in it. */
1006 		ret = devm_request_irq(&pdev->dev, ssi_private->irq,
1007 					fsl_ssi_isr, 0, ssi_private->name,
1008 					ssi_private);
1009 		if (ret < 0) {
1010 			dev_err(&pdev->dev, "could not claim irq %u\n",
1011 					ssi_private->irq);
1012 			goto error_irqmap;
1013 		}
1014 	}
1015 
1016 	/* Initialize the the device_attribute structure */
1017 	dev_attr = &ssi_private->dev_attr;
1018 	sysfs_attr_init(&dev_attr->attr);
1019 	dev_attr->attr.name = "statistics";
1020 	dev_attr->attr.mode = S_IRUGO;
1021 	dev_attr->show = fsl_sysfs_ssi_show;
1022 
1023 	ret = device_create_file(&pdev->dev, dev_attr);
1024 	if (ret) {
1025 		dev_err(&pdev->dev, "could not create sysfs %s file\n",
1026 			ssi_private->dev_attr.attr.name);
1027 		goto error_clk;
1028 	}
1029 
1030 	/* Register with ASoC */
1031 	dev_set_drvdata(&pdev->dev, ssi_private);
1032 
1033 	ret = snd_soc_register_component(&pdev->dev, &fsl_ssi_component,
1034 					 &ssi_private->cpu_dai_drv, 1);
1035 	if (ret) {
1036 		dev_err(&pdev->dev, "failed to register DAI: %d\n", ret);
1037 		goto error_dev;
1038 	}
1039 
1040 	if (ssi_private->ssi_on_imx) {
1041 		if (!ssi_private->use_dma) {
1042 
1043 			/*
1044 			 * Some boards use an incompatible codec. To get it
1045 			 * working, we are using imx-fiq-pcm-audio, that
1046 			 * can handle those codecs. DMA is not possible in this
1047 			 * situation.
1048 			 */
1049 
1050 			ssi_private->fiq_params.irq = ssi_private->irq;
1051 			ssi_private->fiq_params.base = ssi_private->ssi;
1052 			ssi_private->fiq_params.dma_params_rx =
1053 				&ssi_private->dma_params_rx;
1054 			ssi_private->fiq_params.dma_params_tx =
1055 				&ssi_private->dma_params_tx;
1056 
1057 			ret = imx_pcm_fiq_init(pdev, &ssi_private->fiq_params);
1058 			if (ret)
1059 				goto error_dev;
1060 		} else {
1061 			ret = imx_pcm_dma_init(pdev);
1062 			if (ret)
1063 				goto error_dev;
1064 		}
1065 	}
1066 
1067 	/*
1068 	 * If codec-handle property is missing from SSI node, we assume
1069 	 * that the machine driver uses new binding which does not require
1070 	 * SSI driver to trigger machine driver's probe.
1071 	 */
1072 	if (!of_get_property(np, "codec-handle", NULL)) {
1073 		ssi_private->new_binding = true;
1074 		goto done;
1075 	}
1076 
1077 	/* Trigger the machine driver's probe function.  The platform driver
1078 	 * name of the machine driver is taken from /compatible property of the
1079 	 * device tree.  We also pass the address of the CPU DAI driver
1080 	 * structure.
1081 	 */
1082 	sprop = of_get_property(of_find_node_by_path("/"), "compatible", NULL);
1083 	/* Sometimes the compatible name has a "fsl," prefix, so we strip it. */
1084 	p = strrchr(sprop, ',');
1085 	if (p)
1086 		sprop = p + 1;
1087 	snprintf(name, sizeof(name), "snd-soc-%s", sprop);
1088 	make_lowercase(name);
1089 
1090 	ssi_private->pdev =
1091 		platform_device_register_data(&pdev->dev, name, 0, NULL, 0);
1092 	if (IS_ERR(ssi_private->pdev)) {
1093 		ret = PTR_ERR(ssi_private->pdev);
1094 		dev_err(&pdev->dev, "failed to register platform: %d\n", ret);
1095 		goto error_dai;
1096 	}
1097 
1098 done:
1099 	if (ssi_private->imx_ac97)
1100 		fsl_ssi_ac97_init();
1101 
1102 	return 0;
1103 
1104 error_dai:
1105 	if (ssi_private->ssi_on_imx)
1106 		imx_pcm_dma_exit(pdev);
1107 	snd_soc_unregister_component(&pdev->dev);
1108 
1109 error_dev:
1110 	device_remove_file(&pdev->dev, dev_attr);
1111 
1112 error_clk:
1113 	if (ssi_private->ssi_on_imx)
1114 		clk_disable_unprepare(ssi_private->clk);
1115 
1116 error_irqmap:
1117 	irq_dispose_mapping(ssi_private->irq);
1118 
1119 	return ret;
1120 }
1121 
1122 static int fsl_ssi_remove(struct platform_device *pdev)
1123 {
1124 	struct fsl_ssi_private *ssi_private = dev_get_drvdata(&pdev->dev);
1125 
1126 	if (!ssi_private->new_binding)
1127 		platform_device_unregister(ssi_private->pdev);
1128 	if (ssi_private->ssi_on_imx)
1129 		imx_pcm_dma_exit(pdev);
1130 	snd_soc_unregister_component(&pdev->dev);
1131 	device_remove_file(&pdev->dev, &ssi_private->dev_attr);
1132 	if (ssi_private->ssi_on_imx)
1133 		clk_disable_unprepare(ssi_private->clk);
1134 	irq_dispose_mapping(ssi_private->irq);
1135 
1136 	return 0;
1137 }
1138 
1139 static const struct of_device_id fsl_ssi_ids[] = {
1140 	{ .compatible = "fsl,mpc8610-ssi", },
1141 	{ .compatible = "fsl,imx21-ssi", },
1142 	{}
1143 };
1144 MODULE_DEVICE_TABLE(of, fsl_ssi_ids);
1145 
1146 static struct platform_driver fsl_ssi_driver = {
1147 	.driver = {
1148 		.name = "fsl-ssi-dai",
1149 		.owner = THIS_MODULE,
1150 		.of_match_table = fsl_ssi_ids,
1151 	},
1152 	.probe = fsl_ssi_probe,
1153 	.remove = fsl_ssi_remove,
1154 };
1155 
1156 module_platform_driver(fsl_ssi_driver);
1157 
1158 MODULE_ALIAS("platform:fsl-ssi-dai");
1159 MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
1160 MODULE_DESCRIPTION("Freescale Synchronous Serial Interface (SSI) ASoC Driver");
1161 MODULE_LICENSE("GPL v2");
1162