2 * Freescale SSI ALSA SoC Digital Audio Interface (DAI) driver
4 * Author: Timur Tabi <timur@freescale.com>
6 * Copyright 2007-2008 Freescale Semiconductor, Inc. This file is licensed
7 * under the terms of the GNU General Public License version 2. This
8 * program is licensed "as is" without any warranty of any kind, whether
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/interrupt.h>
15 #include <linux/device.h>
16 #include <linux/delay.h>
18 #include <sound/core.h>
19 #include <sound/pcm.h>
20 #include <sound/pcm_params.h>
21 #include <sound/initval.h>
22 #include <sound/soc.h>
24 #include <asm/immap_86xx.h>
29 * FSLSSI_I2S_RATES: sample rates supported by the I2S
31 * This driver currently only supports the SSI running in I2S slave mode,
32 * which means the codec determines the sample rate. Therefore, we tell
33 * ALSA that we support all rates and let the codec driver decide what rates
34 * are really supported.
36 #define FSLSSI_I2S_RATES (SNDRV_PCM_RATE_5512 | SNDRV_PCM_RATE_8000_192000 | \
37 SNDRV_PCM_RATE_CONTINUOUS)
40 * FSLSSI_I2S_FORMATS: audio formats supported by the SSI
42 * This driver currently only supports the SSI running in I2S slave mode.
44 * The SSI has a limitation in that the samples must be in the same byte
45 * order as the host CPU. This is because when multiple bytes are written
46 * to the STX register, the bytes and bits must be written in the same
47 * order. The STX is a shift register, so all the bits need to be aligned
48 * (bit-endianness must match byte-endianness). Processors typically write
49 * the bits within a byte in the same order that the bytes of a word are
50 * written in. So if the host CPU is big-endian, then only big-endian
51 * samples will be written to STX properly.
54 #define FSLSSI_I2S_FORMATS (SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_BE | \
55 SNDRV_PCM_FMTBIT_S18_3BE | SNDRV_PCM_FMTBIT_S20_3BE | \
56 SNDRV_PCM_FMTBIT_S24_3BE | SNDRV_PCM_FMTBIT_S24_BE)
58 #define FSLSSI_I2S_FORMATS (SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_LE | \
59 SNDRV_PCM_FMTBIT_S18_3LE | SNDRV_PCM_FMTBIT_S20_3LE | \
60 SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_LE)
64 * fsl_ssi_private: per-SSI private data
66 * @name: short name for this device ("SSI0", "SSI1", etc)
67 * @ssi: pointer to the SSI's registers
68 * @ssi_phys: physical address of the SSI registers
69 * @irq: IRQ of this SSI
70 * @first_stream: pointer to the stream that was opened first
71 * @second_stream: pointer to second stream
72 * @dev: struct device pointer
73 * @playback: the number of playback streams opened
74 * @capture: the number of capture streams opened
75 * @cpu_dai: the CPU DAI for this device
76 * @dev_attr: the sysfs device attribute structure
77 * @stats: SSI statistics
79 struct fsl_ssi_private {
81 struct ccsr_ssi __iomem *ssi;
84 struct snd_pcm_substream *first_stream;
85 struct snd_pcm_substream *second_stream;
87 unsigned int playback;
89 struct snd_soc_dai cpu_dai;
90 struct device_attribute dev_attr;
118 * fsl_ssi_isr: SSI interrupt handler
120 * Although it's possible to use the interrupt handler to send and receive
121 * data to/from the SSI, we use the DMA instead. Programming is more
122 * complicated, but the performance is much better.
124 * This interrupt handler is used only to gather statistics.
126 * @irq: IRQ of the SSI device
127 * @dev_id: pointer to the ssi_private structure for this SSI device
129 static irqreturn_t fsl_ssi_isr(int irq, void *dev_id)
131 struct fsl_ssi_private *ssi_private = dev_id;
132 struct ccsr_ssi __iomem *ssi = ssi_private->ssi;
133 irqreturn_t ret = IRQ_NONE;
137 /* We got an interrupt, so read the status register to see what we
138 were interrupted for. We mask it with the Interrupt Enable register
139 so that we only check for events that we're interested in.
141 sisr = in_be32(&ssi->sisr) & in_be32(&ssi->sier);
143 if (sisr & CCSR_SSI_SISR_RFRC) {
144 ssi_private->stats.rfrc++;
145 sisr2 |= CCSR_SSI_SISR_RFRC;
149 if (sisr & CCSR_SSI_SISR_TFRC) {
150 ssi_private->stats.tfrc++;
151 sisr2 |= CCSR_SSI_SISR_TFRC;
155 if (sisr & CCSR_SSI_SISR_CMDAU) {
156 ssi_private->stats.cmdau++;
160 if (sisr & CCSR_SSI_SISR_CMDDU) {
161 ssi_private->stats.cmddu++;
165 if (sisr & CCSR_SSI_SISR_RXT) {
166 ssi_private->stats.rxt++;
170 if (sisr & CCSR_SSI_SISR_RDR1) {
171 ssi_private->stats.rdr1++;
175 if (sisr & CCSR_SSI_SISR_RDR0) {
176 ssi_private->stats.rdr0++;
180 if (sisr & CCSR_SSI_SISR_TDE1) {
181 ssi_private->stats.tde1++;
185 if (sisr & CCSR_SSI_SISR_TDE0) {
186 ssi_private->stats.tde0++;
190 if (sisr & CCSR_SSI_SISR_ROE1) {
191 ssi_private->stats.roe1++;
192 sisr2 |= CCSR_SSI_SISR_ROE1;
196 if (sisr & CCSR_SSI_SISR_ROE0) {
197 ssi_private->stats.roe0++;
198 sisr2 |= CCSR_SSI_SISR_ROE0;
202 if (sisr & CCSR_SSI_SISR_TUE1) {
203 ssi_private->stats.tue1++;
204 sisr2 |= CCSR_SSI_SISR_TUE1;
208 if (sisr & CCSR_SSI_SISR_TUE0) {
209 ssi_private->stats.tue0++;
210 sisr2 |= CCSR_SSI_SISR_TUE0;
214 if (sisr & CCSR_SSI_SISR_TFS) {
215 ssi_private->stats.tfs++;
219 if (sisr & CCSR_SSI_SISR_RFS) {
220 ssi_private->stats.rfs++;
224 if (sisr & CCSR_SSI_SISR_TLS) {
225 ssi_private->stats.tls++;
229 if (sisr & CCSR_SSI_SISR_RLS) {
230 ssi_private->stats.rls++;
234 if (sisr & CCSR_SSI_SISR_RFF1) {
235 ssi_private->stats.rff1++;
239 if (sisr & CCSR_SSI_SISR_RFF0) {
240 ssi_private->stats.rff0++;
244 if (sisr & CCSR_SSI_SISR_TFE1) {
245 ssi_private->stats.tfe1++;
249 if (sisr & CCSR_SSI_SISR_TFE0) {
250 ssi_private->stats.tfe0++;
254 /* Clear the bits that we set */
256 out_be32(&ssi->sisr, sisr2);
262 * fsl_ssi_startup: create a new substream
264 * This is the first function called when a stream is opened.
266 * If this is the first stream open, then grab the IRQ and program most of
269 static int fsl_ssi_startup(struct snd_pcm_substream *substream)
271 struct snd_soc_pcm_runtime *rtd = substream->private_data;
272 struct fsl_ssi_private *ssi_private = rtd->dai->cpu_dai->private_data;
275 * If this is the first stream opened, then request the IRQ
276 * and initialize the SSI registers.
278 if (!ssi_private->playback && !ssi_private->capture) {
279 struct ccsr_ssi __iomem *ssi = ssi_private->ssi;
282 ret = request_irq(ssi_private->irq, fsl_ssi_isr, 0,
283 ssi_private->name, ssi_private);
285 dev_err(substream->pcm->card->dev,
286 "could not claim irq %u\n", ssi_private->irq);
291 * Section 16.5 of the MPC8610 reference manual says that the
292 * SSI needs to be disabled before updating the registers we set
295 clrbits32(&ssi->scr, CCSR_SSI_SCR_SSIEN);
298 * Program the SSI into I2S Slave Non-Network Synchronous mode.
299 * Also enable the transmit and receive FIFO.
301 * FIXME: Little-endian samples require a different shift dir
303 clrsetbits_be32(&ssi->scr, CCSR_SSI_SCR_I2S_MODE_MASK,
304 CCSR_SSI_SCR_TFR_CLK_DIS |
305 CCSR_SSI_SCR_I2S_MODE_SLAVE | CCSR_SSI_SCR_SYN);
308 CCSR_SSI_STCR_TXBIT0 | CCSR_SSI_STCR_TFEN0 |
309 CCSR_SSI_STCR_TFSI | CCSR_SSI_STCR_TEFS |
310 CCSR_SSI_STCR_TSCKP);
313 CCSR_SSI_SRCR_RXBIT0 | CCSR_SSI_SRCR_RFEN0 |
314 CCSR_SSI_SRCR_RFSI | CCSR_SSI_SRCR_REFS |
315 CCSR_SSI_SRCR_RSCKP);
318 * The DC and PM bits are only used if the SSI is the clock
322 /* 4. Enable the interrupts and DMA requests */
324 CCSR_SSI_SIER_TFRC_EN | CCSR_SSI_SIER_TDMAE |
325 CCSR_SSI_SIER_TIE | CCSR_SSI_SIER_TUE0_EN |
326 CCSR_SSI_SIER_TUE1_EN | CCSR_SSI_SIER_RFRC_EN |
327 CCSR_SSI_SIER_RDMAE | CCSR_SSI_SIER_RIE |
328 CCSR_SSI_SIER_ROE0_EN | CCSR_SSI_SIER_ROE1_EN);
331 * Set the watermark for transmit FIFI 0 and receive FIFO 0. We
332 * don't use FIFO 1. Since the SSI only supports stereo, the
333 * watermark should never be an odd number.
335 out_be32(&ssi->sfcsr,
336 CCSR_SSI_SFCSR_TFWM0(6) | CCSR_SSI_SFCSR_RFWM0(2));
339 * We keep the SSI disabled because if we enable it, then the
340 * DMA controller will start. It's not supposed to start until
341 * the SCR.TE (or SCR.RE) bit is set, but it does anyway. The
342 * DMA controller will transfer one "BWC" of data (i.e. the
343 * amount of data that the MR.BWC bits are set to). The reason
344 * this is bad is because at this point, the PCM driver has not
345 * finished initializing the DMA controller.
349 if (!ssi_private->first_stream)
350 ssi_private->first_stream = substream;
352 /* This is the second stream open, so we need to impose sample
353 * rate and maybe sample size constraints. Note that this can
354 * cause a race condition if the second stream is opened before
355 * the first stream is fully initialized.
357 * We provide some protection by checking to make sure the first
358 * stream is initialized, but it's not perfect. ALSA sometimes
359 * re-initializes the driver with a different sample rate or
360 * size. If the second stream is opened before the first stream
361 * has received its final parameters, then the second stream may
362 * be constrained to the wrong sample rate or size.
364 * FIXME: This code does not handle opening and closing streams
365 * repeatedly. If you open two streams and then close the first
366 * one, you may not be able to open another stream until you
367 * close the second one as well.
369 struct snd_pcm_runtime *first_runtime =
370 ssi_private->first_stream->runtime;
372 if (!first_runtime->rate || !first_runtime->sample_bits) {
373 dev_err(substream->pcm->card->dev,
374 "set sample rate and size in %s stream first\n",
375 substream->stream == SNDRV_PCM_STREAM_PLAYBACK
376 ? "capture" : "playback");
380 snd_pcm_hw_constraint_minmax(substream->runtime,
381 SNDRV_PCM_HW_PARAM_RATE,
382 first_runtime->rate, first_runtime->rate);
384 snd_pcm_hw_constraint_minmax(substream->runtime,
385 SNDRV_PCM_HW_PARAM_SAMPLE_BITS,
386 first_runtime->sample_bits,
387 first_runtime->sample_bits);
389 ssi_private->second_stream = substream;
392 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
393 ssi_private->playback++;
395 if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
396 ssi_private->capture++;
402 * fsl_ssi_prepare: prepare the SSI.
404 * Most of the SSI registers have been programmed in the startup function,
405 * but the word length must be programmed here. Unfortunately, programming
406 * the SxCCR.WL bits requires the SSI to be temporarily disabled. This can
407 * cause a problem with supporting simultaneous playback and capture. If
408 * the SSI is already playing a stream, then that stream may be temporarily
409 * stopped when you start capture.
411 * Note: The SxCCR.DC and SxCCR.PM bits are only used if the SSI is the
414 static int fsl_ssi_prepare(struct snd_pcm_substream *substream)
416 struct snd_pcm_runtime *runtime = substream->runtime;
417 struct snd_soc_pcm_runtime *rtd = substream->private_data;
418 struct fsl_ssi_private *ssi_private = rtd->dai->cpu_dai->private_data;
420 struct ccsr_ssi __iomem *ssi = ssi_private->ssi;
422 if (substream == ssi_private->first_stream) {
425 /* The SSI should always be disabled at this points (SSIEN=0) */
426 wl = CCSR_SSI_SxCCR_WL(snd_pcm_format_width(runtime->format));
428 /* In synchronous mode, the SSI uses STCCR for capture */
429 clrsetbits_be32(&ssi->stccr, CCSR_SSI_SxCCR_WL_MASK, wl);
436 * fsl_ssi_trigger: start and stop the DMA transfer.
438 * This function is called by ALSA to start, stop, pause, and resume the DMA
441 * The DMA channel is in external master start and pause mode, which
442 * means the SSI completely controls the flow of data.
444 static int fsl_ssi_trigger(struct snd_pcm_substream *substream, int cmd)
446 struct snd_soc_pcm_runtime *rtd = substream->private_data;
447 struct fsl_ssi_private *ssi_private = rtd->dai->cpu_dai->private_data;
448 struct ccsr_ssi __iomem *ssi = ssi_private->ssi;
451 case SNDRV_PCM_TRIGGER_START:
452 case SNDRV_PCM_TRIGGER_RESUME:
453 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
454 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
455 clrbits32(&ssi->scr, CCSR_SSI_SCR_SSIEN);
457 CCSR_SSI_SCR_SSIEN | CCSR_SSI_SCR_TE);
459 clrbits32(&ssi->scr, CCSR_SSI_SCR_SSIEN);
461 CCSR_SSI_SCR_SSIEN | CCSR_SSI_SCR_RE);
464 * I think we need this delay to allow time for the SSI
465 * to put data into its FIFO. Without it, ALSA starts
466 * to complain about overruns.
472 case SNDRV_PCM_TRIGGER_STOP:
473 case SNDRV_PCM_TRIGGER_SUSPEND:
474 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
475 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
476 clrbits32(&ssi->scr, CCSR_SSI_SCR_TE);
478 clrbits32(&ssi->scr, CCSR_SSI_SCR_RE);
489 * fsl_ssi_shutdown: shutdown the SSI
491 * Shutdown the SSI if there are no other substreams open.
493 static void fsl_ssi_shutdown(struct snd_pcm_substream *substream)
495 struct snd_soc_pcm_runtime *rtd = substream->private_data;
496 struct fsl_ssi_private *ssi_private = rtd->dai->cpu_dai->private_data;
498 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
499 ssi_private->playback--;
501 if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
502 ssi_private->capture--;
504 if (ssi_private->first_stream == substream)
505 ssi_private->first_stream = ssi_private->second_stream;
507 ssi_private->second_stream = NULL;
510 * If this is the last active substream, disable the SSI and release
513 if (!ssi_private->playback && !ssi_private->capture) {
514 struct ccsr_ssi __iomem *ssi = ssi_private->ssi;
516 clrbits32(&ssi->scr, CCSR_SSI_SCR_SSIEN);
518 free_irq(ssi_private->irq, ssi_private);
523 * fsl_ssi_set_sysclk: set the clock frequency and direction
525 * This function is called by the machine driver to tell us what the clock
526 * frequency and direction are.
528 * Currently, we only support operating as a clock slave (SND_SOC_CLOCK_IN),
529 * and we don't care about the frequency. Return an error if the direction
530 * is not SND_SOC_CLOCK_IN.
532 * @clk_id: reserved, should be zero
533 * @freq: the frequency of the given clock ID, currently ignored
534 * @dir: SND_SOC_CLOCK_IN (clock slave) or SND_SOC_CLOCK_OUT (clock master)
536 static int fsl_ssi_set_sysclk(struct snd_soc_dai *cpu_dai,
537 int clk_id, unsigned int freq, int dir)
540 return (dir == SND_SOC_CLOCK_IN) ? 0 : -EINVAL;
544 * fsl_ssi_set_fmt: set the serial format.
546 * This function is called by the machine driver to tell us what serial
549 * Currently, we only support I2S mode. Return an error if the format is
550 * not SND_SOC_DAIFMT_I2S.
552 * @format: one of SND_SOC_DAIFMT_xxx
554 static int fsl_ssi_set_fmt(struct snd_soc_dai *cpu_dai, unsigned int format)
556 return (format == SND_SOC_DAIFMT_I2S) ? 0 : -EINVAL;
560 * fsl_ssi_dai_template: template CPU DAI for the SSI
562 static struct snd_soc_dai fsl_ssi_dai_template = {
564 /* The SSI does not support monaural audio. */
567 .rates = FSLSSI_I2S_RATES,
568 .formats = FSLSSI_I2S_FORMATS,
573 .rates = FSLSSI_I2S_RATES,
574 .formats = FSLSSI_I2S_FORMATS,
577 .startup = fsl_ssi_startup,
578 .prepare = fsl_ssi_prepare,
579 .shutdown = fsl_ssi_shutdown,
580 .trigger = fsl_ssi_trigger,
583 .set_sysclk = fsl_ssi_set_sysclk,
584 .set_fmt = fsl_ssi_set_fmt,
589 * fsl_sysfs_ssi_show: display SSI statistics
591 * Display the statistics for the current SSI device.
593 static ssize_t fsl_sysfs_ssi_show(struct device *dev,
594 struct device_attribute *attr, char *buf)
596 struct fsl_ssi_private *ssi_private =
597 container_of(attr, struct fsl_ssi_private, dev_attr);
600 length = sprintf(buf, "rfrc=%u", ssi_private->stats.rfrc);
601 length += sprintf(buf + length, "\ttfrc=%u", ssi_private->stats.tfrc);
602 length += sprintf(buf + length, "\tcmdau=%u", ssi_private->stats.cmdau);
603 length += sprintf(buf + length, "\tcmddu=%u", ssi_private->stats.cmddu);
604 length += sprintf(buf + length, "\trxt=%u", ssi_private->stats.rxt);
605 length += sprintf(buf + length, "\trdr1=%u", ssi_private->stats.rdr1);
606 length += sprintf(buf + length, "\trdr0=%u", ssi_private->stats.rdr0);
607 length += sprintf(buf + length, "\ttde1=%u", ssi_private->stats.tde1);
608 length += sprintf(buf + length, "\ttde0=%u", ssi_private->stats.tde0);
609 length += sprintf(buf + length, "\troe1=%u", ssi_private->stats.roe1);
610 length += sprintf(buf + length, "\troe0=%u", ssi_private->stats.roe0);
611 length += sprintf(buf + length, "\ttue1=%u", ssi_private->stats.tue1);
612 length += sprintf(buf + length, "\ttue0=%u", ssi_private->stats.tue0);
613 length += sprintf(buf + length, "\ttfs=%u", ssi_private->stats.tfs);
614 length += sprintf(buf + length, "\trfs=%u", ssi_private->stats.rfs);
615 length += sprintf(buf + length, "\ttls=%u", ssi_private->stats.tls);
616 length += sprintf(buf + length, "\trls=%u", ssi_private->stats.rls);
617 length += sprintf(buf + length, "\trff1=%u", ssi_private->stats.rff1);
618 length += sprintf(buf + length, "\trff0=%u", ssi_private->stats.rff0);
619 length += sprintf(buf + length, "\ttfe1=%u", ssi_private->stats.tfe1);
620 length += sprintf(buf + length, "\ttfe0=%u\n", ssi_private->stats.tfe0);
626 * fsl_ssi_create_dai: create a snd_soc_dai structure
628 * This function is called by the machine driver to create a snd_soc_dai
629 * structure. The function creates an ssi_private object, which contains
630 * the snd_soc_dai. It also creates the sysfs statistics device.
632 struct snd_soc_dai *fsl_ssi_create_dai(struct fsl_ssi_info *ssi_info)
634 struct snd_soc_dai *fsl_ssi_dai;
635 struct fsl_ssi_private *ssi_private;
637 struct device_attribute *dev_attr;
639 ssi_private = kzalloc(sizeof(struct fsl_ssi_private), GFP_KERNEL);
641 dev_err(ssi_info->dev, "could not allocate DAI object\n");
644 memcpy(&ssi_private->cpu_dai, &fsl_ssi_dai_template,
645 sizeof(struct snd_soc_dai));
647 fsl_ssi_dai = &ssi_private->cpu_dai;
648 dev_attr = &ssi_private->dev_attr;
650 sprintf(ssi_private->name, "ssi%u", (u8) ssi_info->id);
651 ssi_private->ssi = ssi_info->ssi;
652 ssi_private->ssi_phys = ssi_info->ssi_phys;
653 ssi_private->irq = ssi_info->irq;
654 ssi_private->dev = ssi_info->dev;
656 ssi_private->dev->driver_data = fsl_ssi_dai;
658 /* Initialize the the device_attribute structure */
659 dev_attr->attr.name = "ssi-stats";
660 dev_attr->attr.mode = S_IRUGO;
661 dev_attr->show = fsl_sysfs_ssi_show;
663 ret = device_create_file(ssi_private->dev, dev_attr);
665 dev_err(ssi_info->dev, "could not create sysfs %s file\n",
666 ssi_private->dev_attr.attr.name);
671 fsl_ssi_dai->private_data = ssi_private;
672 fsl_ssi_dai->name = ssi_private->name;
673 fsl_ssi_dai->id = ssi_info->id;
677 EXPORT_SYMBOL_GPL(fsl_ssi_create_dai);
680 * fsl_ssi_destroy_dai: destroy the snd_soc_dai object
682 * This function undoes the operations of fsl_ssi_create_dai()
684 void fsl_ssi_destroy_dai(struct snd_soc_dai *fsl_ssi_dai)
686 struct fsl_ssi_private *ssi_private =
687 container_of(fsl_ssi_dai, struct fsl_ssi_private, cpu_dai);
689 device_remove_file(ssi_private->dev, &ssi_private->dev_attr);
693 EXPORT_SYMBOL_GPL(fsl_ssi_destroy_dai);
695 MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
696 MODULE_DESCRIPTION("Freescale Synchronous Serial Interface (SSI) ASoC Driver");
697 MODULE_LICENSE("GPL");