xref: /openbmc/linux/sound/soc/fsl/fsl_ssi.c (revision f35e839a)
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 #include <linux/init.h>
14 #include <linux/io.h>
15 #include <linux/module.h>
16 #include <linux/interrupt.h>
17 #include <linux/clk.h>
18 #include <linux/device.h>
19 #include <linux/delay.h>
20 #include <linux/slab.h>
21 #include <linux/of_address.h>
22 #include <linux/of_irq.h>
23 #include <linux/of_platform.h>
24 
25 #include <sound/core.h>
26 #include <sound/pcm.h>
27 #include <sound/pcm_params.h>
28 #include <sound/initval.h>
29 #include <sound/soc.h>
30 #include <sound/dmaengine_pcm.h>
31 
32 #include "fsl_ssi.h"
33 #include "imx-pcm.h"
34 
35 #ifdef PPC
36 #define read_ssi(addr)			 in_be32(addr)
37 #define write_ssi(val, addr)		 out_be32(addr, val)
38 #define write_ssi_mask(addr, clear, set) clrsetbits_be32(addr, clear, set)
39 #elif defined ARM
40 #define read_ssi(addr)			 readl(addr)
41 #define write_ssi(val, addr)		 writel(val, addr)
42 /*
43  * FIXME: Proper locking should be added at write_ssi_mask caller level
44  * to ensure this register read/modify/write sequence is race free.
45  */
46 static inline void write_ssi_mask(u32 __iomem *addr, u32 clear, u32 set)
47 {
48 	u32 val = readl(addr);
49 	val = (val & ~clear) | set;
50 	writel(val, addr);
51 }
52 #endif
53 
54 /**
55  * FSLSSI_I2S_RATES: sample rates supported by the I2S
56  *
57  * This driver currently only supports the SSI running in I2S slave mode,
58  * which means the codec determines the sample rate.  Therefore, we tell
59  * ALSA that we support all rates and let the codec driver decide what rates
60  * are really supported.
61  */
62 #define FSLSSI_I2S_RATES (SNDRV_PCM_RATE_5512 | SNDRV_PCM_RATE_8000_192000 | \
63 			  SNDRV_PCM_RATE_CONTINUOUS)
64 
65 /**
66  * FSLSSI_I2S_FORMATS: audio formats supported by the SSI
67  *
68  * This driver currently only supports the SSI running in I2S slave mode.
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 /* SIER bitflag of interrupts to enable */
90 #define SIER_FLAGS (CCSR_SSI_SIER_TFRC_EN | CCSR_SSI_SIER_TDMAE | \
91 		    CCSR_SSI_SIER_TIE | CCSR_SSI_SIER_TUE0_EN | \
92 		    CCSR_SSI_SIER_TUE1_EN | CCSR_SSI_SIER_RFRC_EN | \
93 		    CCSR_SSI_SIER_RDMAE | CCSR_SSI_SIER_RIE | \
94 		    CCSR_SSI_SIER_ROE0_EN | CCSR_SSI_SIER_ROE1_EN)
95 
96 /**
97  * fsl_ssi_private: per-SSI private data
98  *
99  * @ssi: pointer to the SSI's registers
100  * @ssi_phys: physical address of the SSI registers
101  * @irq: IRQ of this SSI
102  * @first_stream: pointer to the stream that was opened first
103  * @second_stream: pointer to second stream
104  * @playback: the number of playback streams opened
105  * @capture: the number of capture streams opened
106  * @cpu_dai: the CPU DAI for this device
107  * @dev_attr: the sysfs device attribute structure
108  * @stats: SSI statistics
109  * @name: name for this device
110  */
111 struct fsl_ssi_private {
112 	struct ccsr_ssi __iomem *ssi;
113 	dma_addr_t ssi_phys;
114 	unsigned int irq;
115 	struct snd_pcm_substream *first_stream;
116 	struct snd_pcm_substream *second_stream;
117 	unsigned int fifo_depth;
118 	struct snd_soc_dai_driver cpu_dai_drv;
119 	struct device_attribute dev_attr;
120 	struct platform_device *pdev;
121 
122 	bool new_binding;
123 	bool ssi_on_imx;
124 	struct clk *clk;
125 	struct platform_device *imx_pcm_pdev;
126 	struct snd_dmaengine_dai_dma_data dma_params_tx;
127 	struct snd_dmaengine_dai_dma_data dma_params_rx;
128 	struct imx_dma_data filter_data_tx;
129 	struct imx_dma_data filter_data_rx;
130 
131 	struct {
132 		unsigned int rfrc;
133 		unsigned int tfrc;
134 		unsigned int cmdau;
135 		unsigned int cmddu;
136 		unsigned int rxt;
137 		unsigned int rdr1;
138 		unsigned int rdr0;
139 		unsigned int tde1;
140 		unsigned int tde0;
141 		unsigned int roe1;
142 		unsigned int roe0;
143 		unsigned int tue1;
144 		unsigned int tue0;
145 		unsigned int tfs;
146 		unsigned int rfs;
147 		unsigned int tls;
148 		unsigned int rls;
149 		unsigned int rff1;
150 		unsigned int rff0;
151 		unsigned int tfe1;
152 		unsigned int tfe0;
153 	} stats;
154 
155 	char name[1];
156 };
157 
158 /**
159  * fsl_ssi_isr: SSI interrupt handler
160  *
161  * Although it's possible to use the interrupt handler to send and receive
162  * data to/from the SSI, we use the DMA instead.  Programming is more
163  * complicated, but the performance is much better.
164  *
165  * This interrupt handler is used only to gather statistics.
166  *
167  * @irq: IRQ of the SSI device
168  * @dev_id: pointer to the ssi_private structure for this SSI device
169  */
170 static irqreturn_t fsl_ssi_isr(int irq, void *dev_id)
171 {
172 	struct fsl_ssi_private *ssi_private = dev_id;
173 	struct ccsr_ssi __iomem *ssi = ssi_private->ssi;
174 	irqreturn_t ret = IRQ_NONE;
175 	__be32 sisr;
176 	__be32 sisr2 = 0;
177 
178 	/* We got an interrupt, so read the status register to see what we
179 	   were interrupted for.  We mask it with the Interrupt Enable register
180 	   so that we only check for events that we're interested in.
181 	 */
182 	sisr = read_ssi(&ssi->sisr) & SIER_FLAGS;
183 
184 	if (sisr & CCSR_SSI_SISR_RFRC) {
185 		ssi_private->stats.rfrc++;
186 		sisr2 |= CCSR_SSI_SISR_RFRC;
187 		ret = IRQ_HANDLED;
188 	}
189 
190 	if (sisr & CCSR_SSI_SISR_TFRC) {
191 		ssi_private->stats.tfrc++;
192 		sisr2 |= CCSR_SSI_SISR_TFRC;
193 		ret = IRQ_HANDLED;
194 	}
195 
196 	if (sisr & CCSR_SSI_SISR_CMDAU) {
197 		ssi_private->stats.cmdau++;
198 		ret = IRQ_HANDLED;
199 	}
200 
201 	if (sisr & CCSR_SSI_SISR_CMDDU) {
202 		ssi_private->stats.cmddu++;
203 		ret = IRQ_HANDLED;
204 	}
205 
206 	if (sisr & CCSR_SSI_SISR_RXT) {
207 		ssi_private->stats.rxt++;
208 		ret = IRQ_HANDLED;
209 	}
210 
211 	if (sisr & CCSR_SSI_SISR_RDR1) {
212 		ssi_private->stats.rdr1++;
213 		ret = IRQ_HANDLED;
214 	}
215 
216 	if (sisr & CCSR_SSI_SISR_RDR0) {
217 		ssi_private->stats.rdr0++;
218 		ret = IRQ_HANDLED;
219 	}
220 
221 	if (sisr & CCSR_SSI_SISR_TDE1) {
222 		ssi_private->stats.tde1++;
223 		ret = IRQ_HANDLED;
224 	}
225 
226 	if (sisr & CCSR_SSI_SISR_TDE0) {
227 		ssi_private->stats.tde0++;
228 		ret = IRQ_HANDLED;
229 	}
230 
231 	if (sisr & CCSR_SSI_SISR_ROE1) {
232 		ssi_private->stats.roe1++;
233 		sisr2 |= CCSR_SSI_SISR_ROE1;
234 		ret = IRQ_HANDLED;
235 	}
236 
237 	if (sisr & CCSR_SSI_SISR_ROE0) {
238 		ssi_private->stats.roe0++;
239 		sisr2 |= CCSR_SSI_SISR_ROE0;
240 		ret = IRQ_HANDLED;
241 	}
242 
243 	if (sisr & CCSR_SSI_SISR_TUE1) {
244 		ssi_private->stats.tue1++;
245 		sisr2 |= CCSR_SSI_SISR_TUE1;
246 		ret = IRQ_HANDLED;
247 	}
248 
249 	if (sisr & CCSR_SSI_SISR_TUE0) {
250 		ssi_private->stats.tue0++;
251 		sisr2 |= CCSR_SSI_SISR_TUE0;
252 		ret = IRQ_HANDLED;
253 	}
254 
255 	if (sisr & CCSR_SSI_SISR_TFS) {
256 		ssi_private->stats.tfs++;
257 		ret = IRQ_HANDLED;
258 	}
259 
260 	if (sisr & CCSR_SSI_SISR_RFS) {
261 		ssi_private->stats.rfs++;
262 		ret = IRQ_HANDLED;
263 	}
264 
265 	if (sisr & CCSR_SSI_SISR_TLS) {
266 		ssi_private->stats.tls++;
267 		ret = IRQ_HANDLED;
268 	}
269 
270 	if (sisr & CCSR_SSI_SISR_RLS) {
271 		ssi_private->stats.rls++;
272 		ret = IRQ_HANDLED;
273 	}
274 
275 	if (sisr & CCSR_SSI_SISR_RFF1) {
276 		ssi_private->stats.rff1++;
277 		ret = IRQ_HANDLED;
278 	}
279 
280 	if (sisr & CCSR_SSI_SISR_RFF0) {
281 		ssi_private->stats.rff0++;
282 		ret = IRQ_HANDLED;
283 	}
284 
285 	if (sisr & CCSR_SSI_SISR_TFE1) {
286 		ssi_private->stats.tfe1++;
287 		ret = IRQ_HANDLED;
288 	}
289 
290 	if (sisr & CCSR_SSI_SISR_TFE0) {
291 		ssi_private->stats.tfe0++;
292 		ret = IRQ_HANDLED;
293 	}
294 
295 	/* Clear the bits that we set */
296 	if (sisr2)
297 		write_ssi(sisr2, &ssi->sisr);
298 
299 	return ret;
300 }
301 
302 /**
303  * fsl_ssi_startup: create a new substream
304  *
305  * This is the first function called when a stream is opened.
306  *
307  * If this is the first stream open, then grab the IRQ and program most of
308  * the SSI registers.
309  */
310 static int fsl_ssi_startup(struct snd_pcm_substream *substream,
311 			   struct snd_soc_dai *dai)
312 {
313 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
314 	struct fsl_ssi_private *ssi_private =
315 		snd_soc_dai_get_drvdata(rtd->cpu_dai);
316 	int synchronous = ssi_private->cpu_dai_drv.symmetric_rates;
317 
318 	/*
319 	 * If this is the first stream opened, then request the IRQ
320 	 * and initialize the SSI registers.
321 	 */
322 	if (!ssi_private->first_stream) {
323 		struct ccsr_ssi __iomem *ssi = ssi_private->ssi;
324 
325 		ssi_private->first_stream = substream;
326 
327 		/*
328 		 * Section 16.5 of the MPC8610 reference manual says that the
329 		 * SSI needs to be disabled before updating the registers we set
330 		 * here.
331 		 */
332 		write_ssi_mask(&ssi->scr, CCSR_SSI_SCR_SSIEN, 0);
333 
334 		/*
335 		 * Program the SSI into I2S Slave Non-Network Synchronous mode.
336 		 * Also enable the transmit and receive FIFO.
337 		 *
338 		 * FIXME: Little-endian samples require a different shift dir
339 		 */
340 		write_ssi_mask(&ssi->scr,
341 			CCSR_SSI_SCR_I2S_MODE_MASK | CCSR_SSI_SCR_SYN,
342 			CCSR_SSI_SCR_TFR_CLK_DIS | CCSR_SSI_SCR_I2S_MODE_SLAVE
343 			| (synchronous ? CCSR_SSI_SCR_SYN : 0));
344 
345 		write_ssi(CCSR_SSI_STCR_TXBIT0 | CCSR_SSI_STCR_TFEN0 |
346 			 CCSR_SSI_STCR_TFSI | CCSR_SSI_STCR_TEFS |
347 			 CCSR_SSI_STCR_TSCKP, &ssi->stcr);
348 
349 		write_ssi(CCSR_SSI_SRCR_RXBIT0 | CCSR_SSI_SRCR_RFEN0 |
350 			 CCSR_SSI_SRCR_RFSI | CCSR_SSI_SRCR_REFS |
351 			 CCSR_SSI_SRCR_RSCKP, &ssi->srcr);
352 
353 		/*
354 		 * The DC and PM bits are only used if the SSI is the clock
355 		 * master.
356 		 */
357 
358 		/* Enable the interrupts and DMA requests */
359 		write_ssi(SIER_FLAGS, &ssi->sier);
360 
361 		/*
362 		 * Set the watermark for transmit FIFI 0 and receive FIFO 0. We
363 		 * don't use FIFO 1.  We program the transmit water to signal a
364 		 * DMA transfer if there are only two (or fewer) elements left
365 		 * in the FIFO.  Two elements equals one frame (left channel,
366 		 * right channel).  This value, however, depends on the depth of
367 		 * the transmit buffer.
368 		 *
369 		 * We program the receive FIFO to notify us if at least two
370 		 * elements (one frame) have been written to the FIFO.  We could
371 		 * make this value larger (and maybe we should), but this way
372 		 * data will be written to memory as soon as it's available.
373 		 */
374 		write_ssi(CCSR_SSI_SFCSR_TFWM0(ssi_private->fifo_depth - 2) |
375 			CCSR_SSI_SFCSR_RFWM0(ssi_private->fifo_depth - 2),
376 			&ssi->sfcsr);
377 
378 		/*
379 		 * We keep the SSI disabled because if we enable it, then the
380 		 * DMA controller will start.  It's not supposed to start until
381 		 * the SCR.TE (or SCR.RE) bit is set, but it does anyway.  The
382 		 * DMA controller will transfer one "BWC" of data (i.e. the
383 		 * amount of data that the MR.BWC bits are set to).  The reason
384 		 * this is bad is because at this point, the PCM driver has not
385 		 * finished initializing the DMA controller.
386 		 */
387 	} else {
388 		if (synchronous) {
389 			struct snd_pcm_runtime *first_runtime =
390 				ssi_private->first_stream->runtime;
391 			/*
392 			 * This is the second stream open, and we're in
393 			 * synchronous mode, so we need to impose sample
394 			 * sample size constraints. This is because STCCR is
395 			 * used for playback and capture in synchronous mode,
396 			 * so there's no way to specify different word
397 			 * lengths.
398 			 *
399 			 * Note that this can cause a race condition if the
400 			 * second stream is opened before the first stream is
401 			 * fully initialized.  We provide some protection by
402 			 * checking to make sure the first stream is
403 			 * initialized, but it's not perfect.  ALSA sometimes
404 			 * re-initializes the driver with a different sample
405 			 * rate or size.  If the second stream is opened
406 			 * before the first stream has received its final
407 			 * parameters, then the second stream may be
408 			 * constrained to the wrong sample rate or size.
409 			 */
410 			if (!first_runtime->sample_bits) {
411 				dev_err(substream->pcm->card->dev,
412 					"set sample size in %s stream first\n",
413 					substream->stream ==
414 					SNDRV_PCM_STREAM_PLAYBACK
415 					? "capture" : "playback");
416 				return -EAGAIN;
417 			}
418 
419 			snd_pcm_hw_constraint_minmax(substream->runtime,
420 				SNDRV_PCM_HW_PARAM_SAMPLE_BITS,
421 				first_runtime->sample_bits,
422 				first_runtime->sample_bits);
423 		}
424 
425 		ssi_private->second_stream = substream;
426 	}
427 
428 	return 0;
429 }
430 
431 /**
432  * fsl_ssi_hw_params - program the sample size
433  *
434  * Most of the SSI registers have been programmed in the startup function,
435  * but the word length must be programmed here.  Unfortunately, programming
436  * the SxCCR.WL bits requires the SSI to be temporarily disabled.  This can
437  * cause a problem with supporting simultaneous playback and capture.  If
438  * the SSI is already playing a stream, then that stream may be temporarily
439  * stopped when you start capture.
440  *
441  * Note: The SxCCR.DC and SxCCR.PM bits are only used if the SSI is the
442  * clock master.
443  */
444 static int fsl_ssi_hw_params(struct snd_pcm_substream *substream,
445 	struct snd_pcm_hw_params *hw_params, struct snd_soc_dai *cpu_dai)
446 {
447 	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(cpu_dai);
448 	struct ccsr_ssi __iomem *ssi = ssi_private->ssi;
449 	unsigned int sample_size =
450 		snd_pcm_format_width(params_format(hw_params));
451 	u32 wl = CCSR_SSI_SxCCR_WL(sample_size);
452 	int enabled = read_ssi(&ssi->scr) & CCSR_SSI_SCR_SSIEN;
453 
454 	/*
455 	 * If we're in synchronous mode, and the SSI is already enabled,
456 	 * then STCCR is already set properly.
457 	 */
458 	if (enabled && ssi_private->cpu_dai_drv.symmetric_rates)
459 		return 0;
460 
461 	/*
462 	 * FIXME: The documentation says that SxCCR[WL] should not be
463 	 * modified while the SSI is enabled.  The only time this can
464 	 * happen is if we're trying to do simultaneous playback and
465 	 * capture in asynchronous mode.  Unfortunately, I have been enable
466 	 * to get that to work at all on the P1022DS.  Therefore, we don't
467 	 * bother to disable/enable the SSI when setting SxCCR[WL], because
468 	 * the SSI will stop anyway.  Maybe one day, this will get fixed.
469 	 */
470 
471 	/* In synchronous mode, the SSI uses STCCR for capture */
472 	if ((substream->stream == SNDRV_PCM_STREAM_PLAYBACK) ||
473 	    ssi_private->cpu_dai_drv.symmetric_rates)
474 		write_ssi_mask(&ssi->stccr, CCSR_SSI_SxCCR_WL_MASK, wl);
475 	else
476 		write_ssi_mask(&ssi->srccr, CCSR_SSI_SxCCR_WL_MASK, wl);
477 
478 	return 0;
479 }
480 
481 /**
482  * fsl_ssi_trigger: start and stop the DMA transfer.
483  *
484  * This function is called by ALSA to start, stop, pause, and resume the DMA
485  * transfer of data.
486  *
487  * The DMA channel is in external master start and pause mode, which
488  * means the SSI completely controls the flow of data.
489  */
490 static int fsl_ssi_trigger(struct snd_pcm_substream *substream, int cmd,
491 			   struct snd_soc_dai *dai)
492 {
493 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
494 	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(rtd->cpu_dai);
495 	struct ccsr_ssi __iomem *ssi = ssi_private->ssi;
496 
497 	switch (cmd) {
498 	case SNDRV_PCM_TRIGGER_START:
499 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
500 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
501 			write_ssi_mask(&ssi->scr, 0,
502 				CCSR_SSI_SCR_SSIEN | CCSR_SSI_SCR_TE);
503 		else
504 			write_ssi_mask(&ssi->scr, 0,
505 				CCSR_SSI_SCR_SSIEN | CCSR_SSI_SCR_RE);
506 		break;
507 
508 	case SNDRV_PCM_TRIGGER_STOP:
509 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
510 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
511 			write_ssi_mask(&ssi->scr, CCSR_SSI_SCR_TE, 0);
512 		else
513 			write_ssi_mask(&ssi->scr, CCSR_SSI_SCR_RE, 0);
514 		break;
515 
516 	default:
517 		return -EINVAL;
518 	}
519 
520 	return 0;
521 }
522 
523 /**
524  * fsl_ssi_shutdown: shutdown the SSI
525  *
526  * Shutdown the SSI if there are no other substreams open.
527  */
528 static void fsl_ssi_shutdown(struct snd_pcm_substream *substream,
529 			     struct snd_soc_dai *dai)
530 {
531 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
532 	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(rtd->cpu_dai);
533 
534 	if (ssi_private->first_stream == substream)
535 		ssi_private->first_stream = ssi_private->second_stream;
536 
537 	ssi_private->second_stream = NULL;
538 
539 	/*
540 	 * If this is the last active substream, disable the SSI.
541 	 */
542 	if (!ssi_private->first_stream) {
543 		struct ccsr_ssi __iomem *ssi = ssi_private->ssi;
544 
545 		write_ssi_mask(&ssi->scr, CCSR_SSI_SCR_SSIEN, 0);
546 	}
547 }
548 
549 static int fsl_ssi_dai_probe(struct snd_soc_dai *dai)
550 {
551 	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(dai);
552 
553 	if (ssi_private->ssi_on_imx) {
554 		dai->playback_dma_data = &ssi_private->dma_params_tx;
555 		dai->capture_dma_data = &ssi_private->dma_params_rx;
556 	}
557 
558 	return 0;
559 }
560 
561 static const struct snd_soc_dai_ops fsl_ssi_dai_ops = {
562 	.startup	= fsl_ssi_startup,
563 	.hw_params	= fsl_ssi_hw_params,
564 	.shutdown	= fsl_ssi_shutdown,
565 	.trigger	= fsl_ssi_trigger,
566 };
567 
568 /* Template for the CPU dai driver structure */
569 static struct snd_soc_dai_driver fsl_ssi_dai_template = {
570 	.probe = fsl_ssi_dai_probe,
571 	.playback = {
572 		/* The SSI does not support monaural audio. */
573 		.channels_min = 2,
574 		.channels_max = 2,
575 		.rates = FSLSSI_I2S_RATES,
576 		.formats = FSLSSI_I2S_FORMATS,
577 	},
578 	.capture = {
579 		.channels_min = 2,
580 		.channels_max = 2,
581 		.rates = FSLSSI_I2S_RATES,
582 		.formats = FSLSSI_I2S_FORMATS,
583 	},
584 	.ops = &fsl_ssi_dai_ops,
585 };
586 
587 static const struct snd_soc_component_driver fsl_ssi_component = {
588 	.name		= "fsl-ssi",
589 };
590 
591 /* Show the statistics of a flag only if its interrupt is enabled.  The
592  * compiler will optimze this code to a no-op if the interrupt is not
593  * enabled.
594  */
595 #define SIER_SHOW(flag, name) \
596 	do { \
597 		if (SIER_FLAGS & CCSR_SSI_SIER_##flag) \
598 			length += sprintf(buf + length, #name "=%u\n", \
599 				ssi_private->stats.name); \
600 	} while (0)
601 
602 
603 /**
604  * fsl_sysfs_ssi_show: display SSI statistics
605  *
606  * Display the statistics for the current SSI device.  To avoid confusion,
607  * we only show those counts that are enabled.
608  */
609 static ssize_t fsl_sysfs_ssi_show(struct device *dev,
610 	struct device_attribute *attr, char *buf)
611 {
612 	struct fsl_ssi_private *ssi_private =
613 		container_of(attr, struct fsl_ssi_private, dev_attr);
614 	ssize_t length = 0;
615 
616 	SIER_SHOW(RFRC_EN, rfrc);
617 	SIER_SHOW(TFRC_EN, tfrc);
618 	SIER_SHOW(CMDAU_EN, cmdau);
619 	SIER_SHOW(CMDDU_EN, cmddu);
620 	SIER_SHOW(RXT_EN, rxt);
621 	SIER_SHOW(RDR1_EN, rdr1);
622 	SIER_SHOW(RDR0_EN, rdr0);
623 	SIER_SHOW(TDE1_EN, tde1);
624 	SIER_SHOW(TDE0_EN, tde0);
625 	SIER_SHOW(ROE1_EN, roe1);
626 	SIER_SHOW(ROE0_EN, roe0);
627 	SIER_SHOW(TUE1_EN, tue1);
628 	SIER_SHOW(TUE0_EN, tue0);
629 	SIER_SHOW(TFS_EN, tfs);
630 	SIER_SHOW(RFS_EN, rfs);
631 	SIER_SHOW(TLS_EN, tls);
632 	SIER_SHOW(RLS_EN, rls);
633 	SIER_SHOW(RFF1_EN, rff1);
634 	SIER_SHOW(RFF0_EN, rff0);
635 	SIER_SHOW(TFE1_EN, tfe1);
636 	SIER_SHOW(TFE0_EN, tfe0);
637 
638 	return length;
639 }
640 
641 /**
642  * Make every character in a string lower-case
643  */
644 static void make_lowercase(char *s)
645 {
646 	char *p = s;
647 	char c;
648 
649 	while ((c = *p)) {
650 		if ((c >= 'A') && (c <= 'Z'))
651 			*p = c + ('a' - 'A');
652 		p++;
653 	}
654 }
655 
656 static int fsl_ssi_probe(struct platform_device *pdev)
657 {
658 	struct fsl_ssi_private *ssi_private;
659 	int ret = 0;
660 	struct device_attribute *dev_attr = NULL;
661 	struct device_node *np = pdev->dev.of_node;
662 	const char *p, *sprop;
663 	const uint32_t *iprop;
664 	struct resource res;
665 	char name[64];
666 	bool shared;
667 
668 	/* SSIs that are not connected on the board should have a
669 	 *      status = "disabled"
670 	 * property in their device tree nodes.
671 	 */
672 	if (!of_device_is_available(np))
673 		return -ENODEV;
674 
675 	/* We only support the SSI in "I2S Slave" mode */
676 	sprop = of_get_property(np, "fsl,mode", NULL);
677 	if (!sprop || strcmp(sprop, "i2s-slave")) {
678 		dev_notice(&pdev->dev, "mode %s is unsupported\n", sprop);
679 		return -ENODEV;
680 	}
681 
682 	/* The DAI name is the last part of the full name of the node. */
683 	p = strrchr(np->full_name, '/') + 1;
684 	ssi_private = kzalloc(sizeof(struct fsl_ssi_private) + strlen(p),
685 			      GFP_KERNEL);
686 	if (!ssi_private) {
687 		dev_err(&pdev->dev, "could not allocate DAI object\n");
688 		return -ENOMEM;
689 	}
690 
691 	strcpy(ssi_private->name, p);
692 
693 	/* Initialize this copy of the CPU DAI driver structure */
694 	memcpy(&ssi_private->cpu_dai_drv, &fsl_ssi_dai_template,
695 	       sizeof(fsl_ssi_dai_template));
696 	ssi_private->cpu_dai_drv.name = ssi_private->name;
697 
698 	/* Get the addresses and IRQ */
699 	ret = of_address_to_resource(np, 0, &res);
700 	if (ret) {
701 		dev_err(&pdev->dev, "could not determine device resources\n");
702 		goto error_kmalloc;
703 	}
704 	ssi_private->ssi = of_iomap(np, 0);
705 	if (!ssi_private->ssi) {
706 		dev_err(&pdev->dev, "could not map device resources\n");
707 		ret = -ENOMEM;
708 		goto error_kmalloc;
709 	}
710 	ssi_private->ssi_phys = res.start;
711 
712 	ssi_private->irq = irq_of_parse_and_map(np, 0);
713 	if (ssi_private->irq == NO_IRQ) {
714 		dev_err(&pdev->dev, "no irq for node %s\n", np->full_name);
715 		ret = -ENXIO;
716 		goto error_iomap;
717 	}
718 
719 	/* The 'name' should not have any slashes in it. */
720 	ret = request_irq(ssi_private->irq, fsl_ssi_isr, 0, ssi_private->name,
721 			  ssi_private);
722 	if (ret < 0) {
723 		dev_err(&pdev->dev, "could not claim irq %u\n", ssi_private->irq);
724 		goto error_irqmap;
725 	}
726 
727 	/* Are the RX and the TX clocks locked? */
728 	if (!of_find_property(np, "fsl,ssi-asynchronous", NULL))
729 		ssi_private->cpu_dai_drv.symmetric_rates = 1;
730 
731 	/* Determine the FIFO depth. */
732 	iprop = of_get_property(np, "fsl,fifo-depth", NULL);
733 	if (iprop)
734 		ssi_private->fifo_depth = be32_to_cpup(iprop);
735 	else
736                 /* Older 8610 DTs didn't have the fifo-depth property */
737 		ssi_private->fifo_depth = 8;
738 
739 	if (of_device_is_compatible(pdev->dev.of_node, "fsl,imx21-ssi")) {
740 		u32 dma_events[2];
741 		ssi_private->ssi_on_imx = true;
742 
743 		ssi_private->clk = clk_get(&pdev->dev, NULL);
744 		if (IS_ERR(ssi_private->clk)) {
745 			ret = PTR_ERR(ssi_private->clk);
746 			dev_err(&pdev->dev, "could not get clock: %d\n", ret);
747 			goto error_irq;
748 		}
749 		clk_prepare_enable(ssi_private->clk);
750 
751 		/*
752 		 * We have burstsize be "fifo_depth - 2" to match the SSI
753 		 * watermark setting in fsl_ssi_startup().
754 		 */
755 		ssi_private->dma_params_tx.maxburst =
756 			ssi_private->fifo_depth - 2;
757 		ssi_private->dma_params_rx.maxburst =
758 			ssi_private->fifo_depth - 2;
759 		ssi_private->dma_params_tx.addr =
760 			ssi_private->ssi_phys + offsetof(struct ccsr_ssi, stx0);
761 		ssi_private->dma_params_rx.addr =
762 			ssi_private->ssi_phys + offsetof(struct ccsr_ssi, srx0);
763 		ssi_private->dma_params_tx.filter_data =
764 			&ssi_private->filter_data_tx;
765 		ssi_private->dma_params_rx.filter_data =
766 			&ssi_private->filter_data_rx;
767 		/*
768 		 * TODO: This is a temporary solution and should be changed
769 		 * to use generic DMA binding later when the helplers get in.
770 		 */
771 		ret = of_property_read_u32_array(pdev->dev.of_node,
772 					"fsl,ssi-dma-events", dma_events, 2);
773 		if (ret) {
774 			dev_err(&pdev->dev, "could not get dma events\n");
775 			goto error_clk;
776 		}
777 
778 		shared = of_device_is_compatible(of_get_parent(np),
779 			    "fsl,spba-bus");
780 
781 		imx_pcm_dma_params_init_data(&ssi_private->filter_data_tx,
782 			dma_events[0], shared);
783 		imx_pcm_dma_params_init_data(&ssi_private->filter_data_rx,
784 			dma_events[1], shared);
785 	}
786 
787 	/* Initialize the the device_attribute structure */
788 	dev_attr = &ssi_private->dev_attr;
789 	sysfs_attr_init(&dev_attr->attr);
790 	dev_attr->attr.name = "statistics";
791 	dev_attr->attr.mode = S_IRUGO;
792 	dev_attr->show = fsl_sysfs_ssi_show;
793 
794 	ret = device_create_file(&pdev->dev, dev_attr);
795 	if (ret) {
796 		dev_err(&pdev->dev, "could not create sysfs %s file\n",
797 			ssi_private->dev_attr.attr.name);
798 		goto error_irq;
799 	}
800 
801 	/* Register with ASoC */
802 	dev_set_drvdata(&pdev->dev, ssi_private);
803 
804 	ret = snd_soc_register_component(&pdev->dev, &fsl_ssi_component,
805 					 &ssi_private->cpu_dai_drv, 1);
806 	if (ret) {
807 		dev_err(&pdev->dev, "failed to register DAI: %d\n", ret);
808 		goto error_dev;
809 	}
810 
811 	if (ssi_private->ssi_on_imx) {
812 		ssi_private->imx_pcm_pdev =
813 			platform_device_register_simple("imx-pcm-audio",
814 							-1, NULL, 0);
815 		if (IS_ERR(ssi_private->imx_pcm_pdev)) {
816 			ret = PTR_ERR(ssi_private->imx_pcm_pdev);
817 			goto error_dev;
818 		}
819 	}
820 
821 	/*
822 	 * If codec-handle property is missing from SSI node, we assume
823 	 * that the machine driver uses new binding which does not require
824 	 * SSI driver to trigger machine driver's probe.
825 	 */
826 	if (!of_get_property(np, "codec-handle", NULL)) {
827 		ssi_private->new_binding = true;
828 		goto done;
829 	}
830 
831 	/* Trigger the machine driver's probe function.  The platform driver
832 	 * name of the machine driver is taken from /compatible property of the
833 	 * device tree.  We also pass the address of the CPU DAI driver
834 	 * structure.
835 	 */
836 	sprop = of_get_property(of_find_node_by_path("/"), "compatible", NULL);
837 	/* Sometimes the compatible name has a "fsl," prefix, so we strip it. */
838 	p = strrchr(sprop, ',');
839 	if (p)
840 		sprop = p + 1;
841 	snprintf(name, sizeof(name), "snd-soc-%s", sprop);
842 	make_lowercase(name);
843 
844 	ssi_private->pdev =
845 		platform_device_register_data(&pdev->dev, name, 0, NULL, 0);
846 	if (IS_ERR(ssi_private->pdev)) {
847 		ret = PTR_ERR(ssi_private->pdev);
848 		dev_err(&pdev->dev, "failed to register platform: %d\n", ret);
849 		goto error_dai;
850 	}
851 
852 done:
853 	return 0;
854 
855 error_dai:
856 	if (ssi_private->ssi_on_imx)
857 		platform_device_unregister(ssi_private->imx_pcm_pdev);
858 	snd_soc_unregister_component(&pdev->dev);
859 
860 error_dev:
861 	dev_set_drvdata(&pdev->dev, NULL);
862 	device_remove_file(&pdev->dev, dev_attr);
863 
864 error_clk:
865 	if (ssi_private->ssi_on_imx) {
866 		clk_disable_unprepare(ssi_private->clk);
867 		clk_put(ssi_private->clk);
868 	}
869 
870 error_irq:
871 	free_irq(ssi_private->irq, ssi_private);
872 
873 error_irqmap:
874 	irq_dispose_mapping(ssi_private->irq);
875 
876 error_iomap:
877 	iounmap(ssi_private->ssi);
878 
879 error_kmalloc:
880 	kfree(ssi_private);
881 
882 	return ret;
883 }
884 
885 static int fsl_ssi_remove(struct platform_device *pdev)
886 {
887 	struct fsl_ssi_private *ssi_private = dev_get_drvdata(&pdev->dev);
888 
889 	if (!ssi_private->new_binding)
890 		platform_device_unregister(ssi_private->pdev);
891 	if (ssi_private->ssi_on_imx) {
892 		platform_device_unregister(ssi_private->imx_pcm_pdev);
893 		clk_disable_unprepare(ssi_private->clk);
894 		clk_put(ssi_private->clk);
895 	}
896 	snd_soc_unregister_component(&pdev->dev);
897 	device_remove_file(&pdev->dev, &ssi_private->dev_attr);
898 
899 	free_irq(ssi_private->irq, ssi_private);
900 	irq_dispose_mapping(ssi_private->irq);
901 
902 	kfree(ssi_private);
903 	dev_set_drvdata(&pdev->dev, NULL);
904 
905 	return 0;
906 }
907 
908 static const struct of_device_id fsl_ssi_ids[] = {
909 	{ .compatible = "fsl,mpc8610-ssi", },
910 	{ .compatible = "fsl,imx21-ssi", },
911 	{}
912 };
913 MODULE_DEVICE_TABLE(of, fsl_ssi_ids);
914 
915 static struct platform_driver fsl_ssi_driver = {
916 	.driver = {
917 		.name = "fsl-ssi-dai",
918 		.owner = THIS_MODULE,
919 		.of_match_table = fsl_ssi_ids,
920 	},
921 	.probe = fsl_ssi_probe,
922 	.remove = fsl_ssi_remove,
923 };
924 
925 module_platform_driver(fsl_ssi_driver);
926 
927 MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
928 MODULE_DESCRIPTION("Freescale Synchronous Serial Interface (SSI) ASoC Driver");
929 MODULE_LICENSE("GPL v2");
930