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Linux/sound/soc/codecs/cs4270.c

  1 /*
  2  * CS4270 ALSA SoC (ASoC) codec driver
  3  *
  4  * Author: Timur Tabi <timur@freescale.com>
  5  *
  6  * Copyright 2007-2009 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
  9  * express or implied.
 10  *
 11  * This is an ASoC device driver for the Cirrus Logic CS4270 codec.
 12  *
 13  * Current features/limitations:
 14  *
 15  * - Software mode is supported.  Stand-alone mode is not supported.
 16  * - Only I2C is supported, not SPI
 17  * - Support for master and slave mode
 18  * - The machine driver's 'startup' function must call
 19  *   cs4270_set_dai_sysclk() with the value of MCLK.
 20  * - Only I2S and left-justified modes are supported
 21  * - Power management is supported
 22  */
 23 
 24 #include <linux/module.h>
 25 #include <linux/slab.h>
 26 #include <sound/core.h>
 27 #include <sound/soc.h>
 28 #include <sound/initval.h>
 29 #include <linux/i2c.h>
 30 #include <linux/delay.h>
 31 #include <linux/regulator/consumer.h>
 32 #include <linux/of_device.h>
 33 #include <linux/of_gpio.h>
 34 
 35 /*
 36  * The codec isn't really big-endian or little-endian, since the I2S
 37  * interface requires data to be sent serially with the MSbit first.
 38  * However, to support BE and LE I2S devices, we specify both here.  That
 39  * way, ALSA will always match the bit patterns.
 40  */
 41 #define CS4270_FORMATS (SNDRV_PCM_FMTBIT_S8      | \
 42                         SNDRV_PCM_FMTBIT_S16_LE  | SNDRV_PCM_FMTBIT_S16_BE  | \
 43                         SNDRV_PCM_FMTBIT_S18_3LE | SNDRV_PCM_FMTBIT_S18_3BE | \
 44                         SNDRV_PCM_FMTBIT_S20_3LE | SNDRV_PCM_FMTBIT_S20_3BE | \
 45                         SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_3BE | \
 46                         SNDRV_PCM_FMTBIT_S24_LE  | SNDRV_PCM_FMTBIT_S24_BE)
 47 
 48 /* CS4270 registers addresses */
 49 #define CS4270_CHIPID   0x01    /* Chip ID */
 50 #define CS4270_PWRCTL   0x02    /* Power Control */
 51 #define CS4270_MODE     0x03    /* Mode Control */
 52 #define CS4270_FORMAT   0x04    /* Serial Format, ADC/DAC Control */
 53 #define CS4270_TRANS    0x05    /* Transition Control */
 54 #define CS4270_MUTE     0x06    /* Mute Control */
 55 #define CS4270_VOLA     0x07    /* DAC Channel A Volume Control */
 56 #define CS4270_VOLB     0x08    /* DAC Channel B Volume Control */
 57 
 58 #define CS4270_FIRSTREG 0x01
 59 #define CS4270_LASTREG  0x08
 60 #define CS4270_NUMREGS  (CS4270_LASTREG - CS4270_FIRSTREG + 1)
 61 #define CS4270_I2C_INCR 0x80
 62 
 63 /* Bit masks for the CS4270 registers */
 64 #define CS4270_CHIPID_ID        0xF0
 65 #define CS4270_CHIPID_REV       0x0F
 66 #define CS4270_PWRCTL_FREEZE    0x80
 67 #define CS4270_PWRCTL_PDN_ADC   0x20
 68 #define CS4270_PWRCTL_PDN_DAC   0x02
 69 #define CS4270_PWRCTL_PDN       0x01
 70 #define CS4270_PWRCTL_PDN_ALL   \
 71         (CS4270_PWRCTL_PDN_ADC | CS4270_PWRCTL_PDN_DAC | CS4270_PWRCTL_PDN)
 72 #define CS4270_MODE_SPEED_MASK  0x30
 73 #define CS4270_MODE_1X          0x00
 74 #define CS4270_MODE_2X          0x10
 75 #define CS4270_MODE_4X          0x20
 76 #define CS4270_MODE_SLAVE       0x30
 77 #define CS4270_MODE_DIV_MASK    0x0E
 78 #define CS4270_MODE_DIV1        0x00
 79 #define CS4270_MODE_DIV15       0x02
 80 #define CS4270_MODE_DIV2        0x04
 81 #define CS4270_MODE_DIV3        0x06
 82 #define CS4270_MODE_DIV4        0x08
 83 #define CS4270_MODE_POPGUARD    0x01
 84 #define CS4270_FORMAT_FREEZE_A  0x80
 85 #define CS4270_FORMAT_FREEZE_B  0x40
 86 #define CS4270_FORMAT_LOOPBACK  0x20
 87 #define CS4270_FORMAT_DAC_MASK  0x18
 88 #define CS4270_FORMAT_DAC_LJ    0x00
 89 #define CS4270_FORMAT_DAC_I2S   0x08
 90 #define CS4270_FORMAT_DAC_RJ16  0x18
 91 #define CS4270_FORMAT_DAC_RJ24  0x10
 92 #define CS4270_FORMAT_ADC_MASK  0x01
 93 #define CS4270_FORMAT_ADC_LJ    0x00
 94 #define CS4270_FORMAT_ADC_I2S   0x01
 95 #define CS4270_TRANS_ONE_VOL    0x80
 96 #define CS4270_TRANS_SOFT       0x40
 97 #define CS4270_TRANS_ZERO       0x20
 98 #define CS4270_TRANS_INV_ADC_A  0x08
 99 #define CS4270_TRANS_INV_ADC_B  0x10
100 #define CS4270_TRANS_INV_DAC_A  0x02
101 #define CS4270_TRANS_INV_DAC_B  0x04
102 #define CS4270_TRANS_DEEMPH     0x01
103 #define CS4270_MUTE_AUTO        0x20
104 #define CS4270_MUTE_ADC_A       0x08
105 #define CS4270_MUTE_ADC_B       0x10
106 #define CS4270_MUTE_POLARITY    0x04
107 #define CS4270_MUTE_DAC_A       0x01
108 #define CS4270_MUTE_DAC_B       0x02
109 
110 /* Power-on default values for the registers
111  *
112  * This array contains the power-on default values of the registers, with the
113  * exception of the "CHIPID" register (01h).  The lower four bits of that
114  * register contain the hardware revision, so it is treated as volatile.
115  */
116 static const struct reg_default cs4270_reg_defaults[] = {
117         { 2, 0x00 },
118         { 3, 0x30 },
119         { 4, 0x00 },
120         { 5, 0x60 },
121         { 6, 0x20 },
122         { 7, 0x00 },
123         { 8, 0x00 },
124 };
125 
126 static const char *supply_names[] = {
127         "va", "vd", "vlc"
128 };
129 
130 /* Private data for the CS4270 */
131 struct cs4270_private {
132         struct regmap *regmap;
133         unsigned int mclk; /* Input frequency of the MCLK pin */
134         unsigned int mode; /* The mode (I2S or left-justified) */
135         unsigned int slave_mode;
136         unsigned int manual_mute;
137 
138         /* power domain regulators */
139         struct regulator_bulk_data supplies[ARRAY_SIZE(supply_names)];
140 };
141 
142 static const struct snd_soc_dapm_widget cs4270_dapm_widgets[] = {
143 SND_SOC_DAPM_INPUT("AINL"),
144 SND_SOC_DAPM_INPUT("AINR"),
145 
146 SND_SOC_DAPM_OUTPUT("AOUTL"),
147 SND_SOC_DAPM_OUTPUT("AOUTR"),
148 };
149 
150 static const struct snd_soc_dapm_route cs4270_dapm_routes[] = {
151         { "Capture", NULL, "AINA" },
152         { "Capture", NULL, "AINB" },
153 
154         { "AOUTA", NULL, "Playback" },
155         { "AOUTB", NULL, "Playback" },
156 };
157 
158 /**
159  * struct cs4270_mode_ratios - clock ratio tables
160  * @ratio: the ratio of MCLK to the sample rate
161  * @speed_mode: the Speed Mode bits to set in the Mode Control register for
162  *              this ratio
163  * @mclk: the Ratio Select bits to set in the Mode Control register for this
164  *        ratio
165  *
166  * The data for this chart is taken from Table 5 of the CS4270 reference
167  * manual.
168  *
169  * This table is used to determine how to program the Mode Control register.
170  * It is also used by cs4270_set_dai_sysclk() to tell ALSA which sampling
171  * rates the CS4270 currently supports.
172  *
173  * @speed_mode is the corresponding bit pattern to be written to the
174  * MODE bits of the Mode Control Register
175  *
176  * @mclk is the corresponding bit pattern to be wirten to the MCLK bits of
177  * the Mode Control Register.
178  *
179  * In situations where a single ratio is represented by multiple speed
180  * modes, we favor the slowest speed.  E.g, for a ratio of 128, we pick
181  * double-speed instead of quad-speed.  However, the CS4270 errata states
182  * that divide-By-1.5 can cause failures, so we avoid that mode where
183  * possible.
184  *
185  * Errata: There is an errata for the CS4270 where divide-by-1.5 does not
186  * work if Vd is 3.3V.  If this effects you, select the
187  * CONFIG_SND_SOC_CS4270_VD33_ERRATA Kconfig option, and the driver will
188  * never select any sample rates that require divide-by-1.5.
189  */
190 struct cs4270_mode_ratios {
191         unsigned int ratio;
192         u8 speed_mode;
193         u8 mclk;
194 };
195 
196 static struct cs4270_mode_ratios cs4270_mode_ratios[] = {
197         {64, CS4270_MODE_4X, CS4270_MODE_DIV1},
198 #ifndef CONFIG_SND_SOC_CS4270_VD33_ERRATA
199         {96, CS4270_MODE_4X, CS4270_MODE_DIV15},
200 #endif
201         {128, CS4270_MODE_2X, CS4270_MODE_DIV1},
202         {192, CS4270_MODE_4X, CS4270_MODE_DIV3},
203         {256, CS4270_MODE_1X, CS4270_MODE_DIV1},
204         {384, CS4270_MODE_2X, CS4270_MODE_DIV3},
205         {512, CS4270_MODE_1X, CS4270_MODE_DIV2},
206         {768, CS4270_MODE_1X, CS4270_MODE_DIV3},
207         {1024, CS4270_MODE_1X, CS4270_MODE_DIV4}
208 };
209 
210 /* The number of MCLK/LRCK ratios supported by the CS4270 */
211 #define NUM_MCLK_RATIOS         ARRAY_SIZE(cs4270_mode_ratios)
212 
213 static bool cs4270_reg_is_readable(struct device *dev, unsigned int reg)
214 {
215         return (reg >= CS4270_FIRSTREG) && (reg <= CS4270_LASTREG);
216 }
217 
218 static bool cs4270_reg_is_volatile(struct device *dev, unsigned int reg)
219 {
220         /* Unreadable registers are considered volatile */
221         if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG))
222                 return 1;
223 
224         return reg == CS4270_CHIPID;
225 }
226 
227 /**
228  * cs4270_set_dai_sysclk - determine the CS4270 samples rates.
229  * @codec_dai: the codec DAI
230  * @clk_id: the clock ID (ignored)
231  * @freq: the MCLK input frequency
232  * @dir: the clock direction (ignored)
233  *
234  * This function is used to tell the codec driver what the input MCLK
235  * frequency is.
236  *
237  * The value of MCLK is used to determine which sample rates are supported
238  * by the CS4270.  The ratio of MCLK / Fs must be equal to one of nine
239  * supported values - 64, 96, 128, 192, 256, 384, 512, 768, and 1024.
240  *
241  * This function calculates the nine ratios and determines which ones match
242  * a standard sample rate.  If there's a match, then it is added to the list
243  * of supported sample rates.
244  *
245  * This function must be called by the machine driver's 'startup' function,
246  * otherwise the list of supported sample rates will not be available in
247  * time for ALSA.
248  *
249  * For setups with variable MCLKs, pass 0 as 'freq' argument. This will cause
250  * theoretically possible sample rates to be enabled. Call it again with a
251  * proper value set one the external clock is set (most probably you would do
252  * that from a machine's driver 'hw_param' hook.
253  */
254 static int cs4270_set_dai_sysclk(struct snd_soc_dai *codec_dai,
255                                  int clk_id, unsigned int freq, int dir)
256 {
257         struct snd_soc_codec *codec = codec_dai->codec;
258         struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
259 
260         cs4270->mclk = freq;
261         return 0;
262 }
263 
264 /**
265  * cs4270_set_dai_fmt - configure the codec for the selected audio format
266  * @codec_dai: the codec DAI
267  * @format: a SND_SOC_DAIFMT_x value indicating the data format
268  *
269  * This function takes a bitmask of SND_SOC_DAIFMT_x bits and programs the
270  * codec accordingly.
271  *
272  * Currently, this function only supports SND_SOC_DAIFMT_I2S and
273  * SND_SOC_DAIFMT_LEFT_J.  The CS4270 codec also supports right-justified
274  * data for playback only, but ASoC currently does not support different
275  * formats for playback vs. record.
276  */
277 static int cs4270_set_dai_fmt(struct snd_soc_dai *codec_dai,
278                               unsigned int format)
279 {
280         struct snd_soc_codec *codec = codec_dai->codec;
281         struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
282 
283         /* set DAI format */
284         switch (format & SND_SOC_DAIFMT_FORMAT_MASK) {
285         case SND_SOC_DAIFMT_I2S:
286         case SND_SOC_DAIFMT_LEFT_J:
287                 cs4270->mode = format & SND_SOC_DAIFMT_FORMAT_MASK;
288                 break;
289         default:
290                 dev_err(codec->dev, "invalid dai format\n");
291                 return -EINVAL;
292         }
293 
294         /* set master/slave audio interface */
295         switch (format & SND_SOC_DAIFMT_MASTER_MASK) {
296         case SND_SOC_DAIFMT_CBS_CFS:
297                 cs4270->slave_mode = 1;
298                 break;
299         case SND_SOC_DAIFMT_CBM_CFM:
300                 cs4270->slave_mode = 0;
301                 break;
302         default:
303                 /* all other modes are unsupported by the hardware */
304                 dev_err(codec->dev, "Unknown master/slave configuration\n");
305                 return -EINVAL;
306         }
307 
308         return 0;
309 }
310 
311 /**
312  * cs4270_hw_params - program the CS4270 with the given hardware parameters.
313  * @substream: the audio stream
314  * @params: the hardware parameters to set
315  * @dai: the SOC DAI (ignored)
316  *
317  * This function programs the hardware with the values provided.
318  * Specifically, the sample rate and the data format.
319  *
320  * The .ops functions are used to provide board-specific data, like input
321  * frequencies, to this driver.  This function takes that information,
322  * combines it with the hardware parameters provided, and programs the
323  * hardware accordingly.
324  */
325 static int cs4270_hw_params(struct snd_pcm_substream *substream,
326                             struct snd_pcm_hw_params *params,
327                             struct snd_soc_dai *dai)
328 {
329         struct snd_soc_codec *codec = dai->codec;
330         struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
331         int ret;
332         unsigned int i;
333         unsigned int rate;
334         unsigned int ratio;
335         int reg;
336 
337         /* Figure out which MCLK/LRCK ratio to use */
338 
339         rate = params_rate(params);     /* Sampling rate, in Hz */
340         ratio = cs4270->mclk / rate;    /* MCLK/LRCK ratio */
341 
342         for (i = 0; i < NUM_MCLK_RATIOS; i++) {
343                 if (cs4270_mode_ratios[i].ratio == ratio)
344                         break;
345         }
346 
347         if (i == NUM_MCLK_RATIOS) {
348                 /* We did not find a matching ratio */
349                 dev_err(codec->dev, "could not find matching ratio\n");
350                 return -EINVAL;
351         }
352 
353         /* Set the sample rate */
354 
355         reg = snd_soc_read(codec, CS4270_MODE);
356         reg &= ~(CS4270_MODE_SPEED_MASK | CS4270_MODE_DIV_MASK);
357         reg |= cs4270_mode_ratios[i].mclk;
358 
359         if (cs4270->slave_mode)
360                 reg |= CS4270_MODE_SLAVE;
361         else
362                 reg |= cs4270_mode_ratios[i].speed_mode;
363 
364         ret = snd_soc_write(codec, CS4270_MODE, reg);
365         if (ret < 0) {
366                 dev_err(codec->dev, "i2c write failed\n");
367                 return ret;
368         }
369 
370         /* Set the DAI format */
371 
372         reg = snd_soc_read(codec, CS4270_FORMAT);
373         reg &= ~(CS4270_FORMAT_DAC_MASK | CS4270_FORMAT_ADC_MASK);
374 
375         switch (cs4270->mode) {
376         case SND_SOC_DAIFMT_I2S:
377                 reg |= CS4270_FORMAT_DAC_I2S | CS4270_FORMAT_ADC_I2S;
378                 break;
379         case SND_SOC_DAIFMT_LEFT_J:
380                 reg |= CS4270_FORMAT_DAC_LJ | CS4270_FORMAT_ADC_LJ;
381                 break;
382         default:
383                 dev_err(codec->dev, "unknown dai format\n");
384                 return -EINVAL;
385         }
386 
387         ret = snd_soc_write(codec, CS4270_FORMAT, reg);
388         if (ret < 0) {
389                 dev_err(codec->dev, "i2c write failed\n");
390                 return ret;
391         }
392 
393         return ret;
394 }
395 
396 /**
397  * cs4270_dai_mute - enable/disable the CS4270 external mute
398  * @dai: the SOC DAI
399  * @mute: 0 = disable mute, 1 = enable mute
400  *
401  * This function toggles the mute bits in the MUTE register.  The CS4270's
402  * mute capability is intended for external muting circuitry, so if the
403  * board does not have the MUTEA or MUTEB pins connected to such circuitry,
404  * then this function will do nothing.
405  */
406 static int cs4270_dai_mute(struct snd_soc_dai *dai, int mute)
407 {
408         struct snd_soc_codec *codec = dai->codec;
409         struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
410         int reg6;
411 
412         reg6 = snd_soc_read(codec, CS4270_MUTE);
413 
414         if (mute)
415                 reg6 |= CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B;
416         else {
417                 reg6 &= ~(CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B);
418                 reg6 |= cs4270->manual_mute;
419         }
420 
421         return snd_soc_write(codec, CS4270_MUTE, reg6);
422 }
423 
424 /**
425  * cs4270_soc_put_mute - put callback for the 'Master Playback switch'
426  *                       alsa control.
427  * @kcontrol: mixer control
428  * @ucontrol: control element information
429  *
430  * This function basically passes the arguments on to the generic
431  * snd_soc_put_volsw() function and saves the mute information in
432  * our private data structure. This is because we want to prevent
433  * cs4270_dai_mute() neglecting the user's decision to manually
434  * mute the codec's output.
435  *
436  * Returns 0 for success.
437  */
438 static int cs4270_soc_put_mute(struct snd_kcontrol *kcontrol,
439                                 struct snd_ctl_elem_value *ucontrol)
440 {
441         struct snd_soc_codec *codec = snd_soc_kcontrol_codec(kcontrol);
442         struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
443         int left = !ucontrol->value.integer.value[0];
444         int right = !ucontrol->value.integer.value[1];
445 
446         cs4270->manual_mute = (left ? CS4270_MUTE_DAC_A : 0) |
447                               (right ? CS4270_MUTE_DAC_B : 0);
448 
449         return snd_soc_put_volsw(kcontrol, ucontrol);
450 }
451 
452 /* A list of non-DAPM controls that the CS4270 supports */
453 static const struct snd_kcontrol_new cs4270_snd_controls[] = {
454         SOC_DOUBLE_R("Master Playback Volume",
455                 CS4270_VOLA, CS4270_VOLB, 0, 0xFF, 1),
456         SOC_SINGLE("Digital Sidetone Switch", CS4270_FORMAT, 5, 1, 0),
457         SOC_SINGLE("Soft Ramp Switch", CS4270_TRANS, 6, 1, 0),
458         SOC_SINGLE("Zero Cross Switch", CS4270_TRANS, 5, 1, 0),
459         SOC_SINGLE("De-emphasis filter", CS4270_TRANS, 0, 1, 0),
460         SOC_SINGLE("Popguard Switch", CS4270_MODE, 0, 1, 1),
461         SOC_SINGLE("Auto-Mute Switch", CS4270_MUTE, 5, 1, 0),
462         SOC_DOUBLE("Master Capture Switch", CS4270_MUTE, 3, 4, 1, 1),
463         SOC_DOUBLE_EXT("Master Playback Switch", CS4270_MUTE, 0, 1, 1, 1,
464                 snd_soc_get_volsw, cs4270_soc_put_mute),
465 };
466 
467 static const struct snd_soc_dai_ops cs4270_dai_ops = {
468         .hw_params      = cs4270_hw_params,
469         .set_sysclk     = cs4270_set_dai_sysclk,
470         .set_fmt        = cs4270_set_dai_fmt,
471         .digital_mute   = cs4270_dai_mute,
472 };
473 
474 static struct snd_soc_dai_driver cs4270_dai = {
475         .name = "cs4270-hifi",
476         .playback = {
477                 .stream_name = "Playback",
478                 .channels_min = 2,
479                 .channels_max = 2,
480                 .rates = SNDRV_PCM_RATE_CONTINUOUS,
481                 .rate_min = 4000,
482                 .rate_max = 216000,
483                 .formats = CS4270_FORMATS,
484         },
485         .capture = {
486                 .stream_name = "Capture",
487                 .channels_min = 2,
488                 .channels_max = 2,
489                 .rates = SNDRV_PCM_RATE_CONTINUOUS,
490                 .rate_min = 4000,
491                 .rate_max = 216000,
492                 .formats = CS4270_FORMATS,
493         },
494         .ops = &cs4270_dai_ops,
495 };
496 
497 /**
498  * cs4270_probe - ASoC probe function
499  * @pdev: platform device
500  *
501  * This function is called when ASoC has all the pieces it needs to
502  * instantiate a sound driver.
503  */
504 static int cs4270_probe(struct snd_soc_codec *codec)
505 {
506         struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
507         int ret;
508 
509         /* Disable auto-mute.  This feature appears to be buggy.  In some
510          * situations, auto-mute will not deactivate when it should, so we want
511          * this feature disabled by default.  An application (e.g. alsactl) can
512          * re-enabled it by using the controls.
513          */
514         ret = snd_soc_update_bits(codec, CS4270_MUTE, CS4270_MUTE_AUTO, 0);
515         if (ret < 0) {
516                 dev_err(codec->dev, "i2c write failed\n");
517                 return ret;
518         }
519 
520         /* Disable automatic volume control.  The hardware enables, and it
521          * causes volume change commands to be delayed, sometimes until after
522          * playback has started.  An application (e.g. alsactl) can
523          * re-enabled it by using the controls.
524          */
525         ret = snd_soc_update_bits(codec, CS4270_TRANS,
526                 CS4270_TRANS_SOFT | CS4270_TRANS_ZERO, 0);
527         if (ret < 0) {
528                 dev_err(codec->dev, "i2c write failed\n");
529                 return ret;
530         }
531 
532         ret = regulator_bulk_enable(ARRAY_SIZE(cs4270->supplies),
533                                     cs4270->supplies);
534 
535         return ret;
536 }
537 
538 /**
539  * cs4270_remove - ASoC remove function
540  * @pdev: platform device
541  *
542  * This function is the counterpart to cs4270_probe().
543  */
544 static int cs4270_remove(struct snd_soc_codec *codec)
545 {
546         struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
547 
548         regulator_bulk_disable(ARRAY_SIZE(cs4270->supplies), cs4270->supplies);
549 
550         return 0;
551 };
552 
553 #ifdef CONFIG_PM
554 
555 /* This suspend/resume implementation can handle both - a simple standby
556  * where the codec remains powered, and a full suspend, where the voltage
557  * domain the codec is connected to is teared down and/or any other hardware
558  * reset condition is asserted.
559  *
560  * The codec's own power saving features are enabled in the suspend callback,
561  * and all registers are written back to the hardware when resuming.
562  */
563 
564 static int cs4270_soc_suspend(struct snd_soc_codec *codec)
565 {
566         struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
567         int reg, ret;
568 
569         reg = snd_soc_read(codec, CS4270_PWRCTL) | CS4270_PWRCTL_PDN_ALL;
570         if (reg < 0)
571                 return reg;
572 
573         ret = snd_soc_write(codec, CS4270_PWRCTL, reg);
574         if (ret < 0)
575                 return ret;
576 
577         regulator_bulk_disable(ARRAY_SIZE(cs4270->supplies),
578                                cs4270->supplies);
579 
580         return 0;
581 }
582 
583 static int cs4270_soc_resume(struct snd_soc_codec *codec)
584 {
585         struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
586         int reg, ret;
587 
588         ret = regulator_bulk_enable(ARRAY_SIZE(cs4270->supplies),
589                                     cs4270->supplies);
590         if (ret != 0)
591                 return ret;
592 
593         /* In case the device was put to hard reset during sleep, we need to
594          * wait 500ns here before any I2C communication. */
595         ndelay(500);
596 
597         /* first restore the entire register cache ... */
598         regcache_sync(cs4270->regmap);
599 
600         /* ... then disable the power-down bits */
601         reg = snd_soc_read(codec, CS4270_PWRCTL);
602         reg &= ~CS4270_PWRCTL_PDN_ALL;
603 
604         return snd_soc_write(codec, CS4270_PWRCTL, reg);
605 }
606 #else
607 #define cs4270_soc_suspend      NULL
608 #define cs4270_soc_resume       NULL
609 #endif /* CONFIG_PM */
610 
611 /*
612  * ASoC codec driver structure
613  */
614 static const struct snd_soc_codec_driver soc_codec_device_cs4270 = {
615         .probe =                cs4270_probe,
616         .remove =               cs4270_remove,
617         .suspend =              cs4270_soc_suspend,
618         .resume =               cs4270_soc_resume,
619 
620         .controls =             cs4270_snd_controls,
621         .num_controls =         ARRAY_SIZE(cs4270_snd_controls),
622         .dapm_widgets =         cs4270_dapm_widgets,
623         .num_dapm_widgets =     ARRAY_SIZE(cs4270_dapm_widgets),
624         .dapm_routes =          cs4270_dapm_routes,
625         .num_dapm_routes =      ARRAY_SIZE(cs4270_dapm_routes),
626 };
627 
628 /*
629  * cs4270_of_match - the device tree bindings
630  */
631 static const struct of_device_id cs4270_of_match[] = {
632         { .compatible = "cirrus,cs4270", },
633         { }
634 };
635 MODULE_DEVICE_TABLE(of, cs4270_of_match);
636 
637 static const struct regmap_config cs4270_regmap = {
638         .reg_bits =             8,
639         .val_bits =             8,
640         .max_register =         CS4270_LASTREG,
641         .reg_defaults =         cs4270_reg_defaults,
642         .num_reg_defaults =     ARRAY_SIZE(cs4270_reg_defaults),
643         .cache_type =           REGCACHE_RBTREE,
644 
645         .readable_reg =         cs4270_reg_is_readable,
646         .volatile_reg =         cs4270_reg_is_volatile,
647 };
648 
649 /**
650  * cs4270_i2c_probe - initialize the I2C interface of the CS4270
651  * @i2c_client: the I2C client object
652  * @id: the I2C device ID (ignored)
653  *
654  * This function is called whenever the I2C subsystem finds a device that
655  * matches the device ID given via a prior call to i2c_add_driver().
656  */
657 static int cs4270_i2c_probe(struct i2c_client *i2c_client,
658         const struct i2c_device_id *id)
659 {
660         struct device_node *np = i2c_client->dev.of_node;
661         struct cs4270_private *cs4270;
662         unsigned int val;
663         int ret, i;
664 
665         cs4270 = devm_kzalloc(&i2c_client->dev, sizeof(struct cs4270_private),
666                               GFP_KERNEL);
667         if (!cs4270)
668                 return -ENOMEM;
669 
670         /* get the power supply regulators */
671         for (i = 0; i < ARRAY_SIZE(supply_names); i++)
672                 cs4270->supplies[i].supply = supply_names[i];
673 
674         ret = devm_regulator_bulk_get(&i2c_client->dev,
675                                       ARRAY_SIZE(cs4270->supplies),
676                                       cs4270->supplies);
677         if (ret < 0)
678                 return ret;
679 
680         /* See if we have a way to bring the codec out of reset */
681         if (np) {
682                 enum of_gpio_flags flags;
683                 int gpio = of_get_named_gpio_flags(np, "reset-gpio", 0, &flags);
684 
685                 if (gpio_is_valid(gpio)) {
686                         ret = devm_gpio_request_one(&i2c_client->dev, gpio,
687                                      flags & OF_GPIO_ACTIVE_LOW ?
688                                         GPIOF_OUT_INIT_LOW : GPIOF_OUT_INIT_HIGH,
689                                      "cs4270 reset");
690                         if (ret < 0)
691                                 return ret;
692                 }
693         }
694 
695         cs4270->regmap = devm_regmap_init_i2c(i2c_client, &cs4270_regmap);
696         if (IS_ERR(cs4270->regmap))
697                 return PTR_ERR(cs4270->regmap);
698 
699         /* Verify that we have a CS4270 */
700         ret = regmap_read(cs4270->regmap, CS4270_CHIPID, &val);
701         if (ret < 0) {
702                 dev_err(&i2c_client->dev, "failed to read i2c at addr %X\n",
703                        i2c_client->addr);
704                 return ret;
705         }
706         /* The top four bits of the chip ID should be 1100. */
707         if ((val & 0xF0) != 0xC0) {
708                 dev_err(&i2c_client->dev, "device at addr %X is not a CS4270\n",
709                        i2c_client->addr);
710                 return -ENODEV;
711         }
712 
713         dev_info(&i2c_client->dev, "found device at i2c address %X\n",
714                 i2c_client->addr);
715         dev_info(&i2c_client->dev, "hardware revision %X\n", val & 0xF);
716 
717         i2c_set_clientdata(i2c_client, cs4270);
718 
719         ret = snd_soc_register_codec(&i2c_client->dev,
720                         &soc_codec_device_cs4270, &cs4270_dai, 1);
721         return ret;
722 }
723 
724 /**
725  * cs4270_i2c_remove - remove an I2C device
726  * @i2c_client: the I2C client object
727  *
728  * This function is the counterpart to cs4270_i2c_probe().
729  */
730 static int cs4270_i2c_remove(struct i2c_client *i2c_client)
731 {
732         snd_soc_unregister_codec(&i2c_client->dev);
733         return 0;
734 }
735 
736 /*
737  * cs4270_id - I2C device IDs supported by this driver
738  */
739 static const struct i2c_device_id cs4270_id[] = {
740         {"cs4270", 0},
741         {}
742 };
743 MODULE_DEVICE_TABLE(i2c, cs4270_id);
744 
745 /*
746  * cs4270_i2c_driver - I2C device identification
747  *
748  * This structure tells the I2C subsystem how to identify and support a
749  * given I2C device type.
750  */
751 static struct i2c_driver cs4270_i2c_driver = {
752         .driver = {
753                 .name = "cs4270",
754                 .owner = THIS_MODULE,
755                 .of_match_table = cs4270_of_match,
756         },
757         .id_table = cs4270_id,
758         .probe = cs4270_i2c_probe,
759         .remove = cs4270_i2c_remove,
760 };
761 
762 module_i2c_driver(cs4270_i2c_driver);
763 
764 MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
765 MODULE_DESCRIPTION("Cirrus Logic CS4270 ALSA SoC Codec Driver");
766 MODULE_LICENSE("GPL");
767 

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