/* * cs42l51.c * * ASoC Driver for Cirrus Logic CS42L51 codecs * * Copyright (c) 2010 Arnaud Patard * * Based on cs4270.c - Copyright (c) Freescale Semiconductor * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * For now: * - Only I2C is support. Not SPI * - master mode *NOT* supported */ #include #include #include #include #include #include #include #include #include #include #include #include "cs42l51.h" enum master_slave_mode { MODE_SLAVE, MODE_SLAVE_AUTO, MODE_MASTER, }; struct cs42l51_private { enum snd_soc_control_type control_type; void *control_data; unsigned int mclk; unsigned int audio_mode; /* The mode (I2S or left-justified) */ enum master_slave_mode func; u8 reg_cache[CS42L51_NUMREGS]; }; #define CS42L51_FORMATS ( \ SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE | \ SNDRV_PCM_FMTBIT_S18_3LE | SNDRV_PCM_FMTBIT_S18_3BE | \ SNDRV_PCM_FMTBIT_S20_3LE | SNDRV_PCM_FMTBIT_S20_3BE | \ SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S24_BE) static int cs42l51_fill_cache(struct snd_soc_codec *codec) { u8 *cache = codec->reg_cache + 1; struct i2c_client *i2c_client = codec->control_data; s32 length; length = i2c_smbus_read_i2c_block_data(i2c_client, CS42L51_FIRSTREG | 0x80, CS42L51_NUMREGS, cache); if (length != CS42L51_NUMREGS) { dev_err(&i2c_client->dev, "I2C read failure, addr=0x%x (ret=%d vs %d)\n", i2c_client->addr, length, CS42L51_NUMREGS); return -EIO; } return 0; } static int cs42l51_get_chan_mix(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol) { struct snd_soc_codec *codec = snd_kcontrol_chip(kcontrol); unsigned long value = snd_soc_read(codec, CS42L51_PCM_MIXER)&3; switch (value) { default: case 0: ucontrol->value.integer.value[0] = 0; break; /* same value : (L+R)/2 and (R+L)/2 */ case 1: case 2: ucontrol->value.integer.value[0] = 1; break; case 3: ucontrol->value.integer.value[0] = 2; break; } return 0; } #define CHAN_MIX_NORMAL 0x00 #define CHAN_MIX_BOTH 0x55 #define CHAN_MIX_SWAP 0xFF static int cs42l51_set_chan_mix(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol) { struct snd_soc_codec *codec = snd_kcontrol_chip(kcontrol); unsigned char val; switch (ucontrol->value.integer.value[0]) { default: case 0: val = CHAN_MIX_NORMAL; break; case 1: val = CHAN_MIX_BOTH; break; case 2: val = CHAN_MIX_SWAP; break; } snd_soc_write(codec, CS42L51_PCM_MIXER, val); return 1; } static const DECLARE_TLV_DB_SCALE(adc_pcm_tlv, -5150, 50, 0); static const DECLARE_TLV_DB_SCALE(tone_tlv, -1050, 150, 0); /* This is a lie. after -102 db, it stays at -102 */ /* maybe a range would be better */ static const DECLARE_TLV_DB_SCALE(aout_tlv, -11550, 50, 0); static const DECLARE_TLV_DB_SCALE(boost_tlv, 1600, 1600, 0); static const char *chan_mix[] = { "L R", "L+R", "R L", }; static const struct soc_enum cs42l51_chan_mix = SOC_ENUM_SINGLE_EXT(ARRAY_SIZE(chan_mix), chan_mix); static const struct snd_kcontrol_new cs42l51_snd_controls[] = { SOC_DOUBLE_R_SX_TLV("PCM Playback Volume", CS42L51_PCMA_VOL, CS42L51_PCMB_VOL, 7, 0xffffff99, 0x18, adc_pcm_tlv), SOC_DOUBLE_R("PCM Playback Switch", CS42L51_PCMA_VOL, CS42L51_PCMB_VOL, 7, 1, 1), SOC_DOUBLE_R_SX_TLV("Analog Playback Volume", CS42L51_AOUTA_VOL, CS42L51_AOUTB_VOL, 8, 0xffffff19, 0x18, aout_tlv), SOC_DOUBLE_R_SX_TLV("ADC Mixer Volume", CS42L51_ADCA_VOL, CS42L51_ADCB_VOL, 7, 0xffffff99, 0x18, adc_pcm_tlv), SOC_DOUBLE_R("ADC Mixer Switch", CS42L51_ADCA_VOL, CS42L51_ADCB_VOL, 7, 1, 1), SOC_SINGLE("Playback Deemphasis Switch", CS42L51_DAC_CTL, 3, 1, 0), SOC_SINGLE("Auto-Mute Switch", CS42L51_DAC_CTL, 2, 1, 0), SOC_SINGLE("Soft Ramp Switch", CS42L51_DAC_CTL, 1, 1, 0), SOC_SINGLE("Zero Cross Switch", CS42L51_DAC_CTL, 0, 0, 0), SOC_DOUBLE_TLV("Mic Boost Volume", CS42L51_MIC_CTL, 0, 1, 1, 0, boost_tlv), SOC_SINGLE_TLV("Bass Volume", CS42L51_TONE_CTL, 0, 0xf, 1, tone_tlv), SOC_SINGLE_TLV("Treble Volume", CS42L51_TONE_CTL, 4, 0xf, 1, tone_tlv), SOC_ENUM_EXT("PCM channel mixer", cs42l51_chan_mix, cs42l51_get_chan_mix, cs42l51_set_chan_mix), }; /* * to power down, one must: * 1.) Enable the PDN bit * 2.) enable power-down for the select channels * 3.) disable the PDN bit. */ static int cs42l51_pdn_event(struct snd_soc_dapm_widget *w, struct snd_kcontrol *kcontrol, int event) { unsigned long value; value = snd_soc_read(w->codec, CS42L51_POWER_CTL1); value &= ~CS42L51_POWER_CTL1_PDN; switch (event) { case SND_SOC_DAPM_PRE_PMD: value |= CS42L51_POWER_CTL1_PDN; break; default: case SND_SOC_DAPM_POST_PMD: break; } snd_soc_update_bits(w->codec, CS42L51_POWER_CTL1, CS42L51_POWER_CTL1_PDN, value); return 0; } static const char *cs42l51_dac_names[] = {"Direct PCM", "DSP PCM", "ADC"}; static const struct soc_enum cs42l51_dac_mux_enum = SOC_ENUM_SINGLE(CS42L51_DAC_CTL, 6, 3, cs42l51_dac_names); static const struct snd_kcontrol_new cs42l51_dac_mux_controls = SOC_DAPM_ENUM("Route", cs42l51_dac_mux_enum); static const char *cs42l51_adcl_names[] = {"AIN1 Left", "AIN2 Left", "MIC Left", "MIC+preamp Left"}; static const struct soc_enum cs42l51_adcl_mux_enum = SOC_ENUM_SINGLE(CS42L51_ADC_INPUT, 4, 4, cs42l51_adcl_names); static const struct snd_kcontrol_new cs42l51_adcl_mux_controls = SOC_DAPM_ENUM("Route", cs42l51_adcl_mux_enum); static const char *cs42l51_adcr_names[] = {"AIN1 Right", "AIN2 Right", "MIC Right", "MIC+preamp Right"}; static const struct soc_enum cs42l51_adcr_mux_enum = SOC_ENUM_SINGLE(CS42L51_ADC_INPUT, 6, 4, cs42l51_adcr_names); static const struct snd_kcontrol_new cs42l51_adcr_mux_controls = SOC_DAPM_ENUM("Route", cs42l51_adcr_mux_enum); static const struct snd_soc_dapm_widget cs42l51_dapm_widgets[] = { SND_SOC_DAPM_MICBIAS("Mic Bias", CS42L51_MIC_POWER_CTL, 1, 1), SND_SOC_DAPM_PGA_E("Left PGA", CS42L51_POWER_CTL1, 3, 1, NULL, 0, cs42l51_pdn_event, SND_SOC_DAPM_PRE_POST_PMD), SND_SOC_DAPM_PGA_E("Right PGA", CS42L51_POWER_CTL1, 4, 1, NULL, 0, cs42l51_pdn_event, SND_SOC_DAPM_PRE_POST_PMD), SND_SOC_DAPM_ADC_E("Left ADC", "Left HiFi Capture", CS42L51_POWER_CTL1, 1, 1, cs42l51_pdn_event, SND_SOC_DAPM_PRE_POST_PMD), SND_SOC_DAPM_ADC_E("Right ADC", "Right HiFi Capture", CS42L51_POWER_CTL1, 2, 1, cs42l51_pdn_event, SND_SOC_DAPM_PRE_POST_PMD), SND_SOC_DAPM_DAC_E("Left DAC", "Left HiFi Playback", CS42L51_POWER_CTL1, 5, 1, cs42l51_pdn_event, SND_SOC_DAPM_PRE_POST_PMD), SND_SOC_DAPM_DAC_E("Right DAC", "Right HiFi Playback", CS42L51_POWER_CTL1, 6, 1, cs42l51_pdn_event, SND_SOC_DAPM_PRE_POST_PMD), /* analog/mic */ SND_SOC_DAPM_INPUT("AIN1L"), SND_SOC_DAPM_INPUT("AIN1R"), SND_SOC_DAPM_INPUT("AIN2L"), SND_SOC_DAPM_INPUT("AIN2R"), SND_SOC_DAPM_INPUT("MICL"), SND_SOC_DAPM_INPUT("MICR"), SND_SOC_DAPM_MIXER("Mic Preamp Left", CS42L51_MIC_POWER_CTL, 2, 1, NULL, 0), SND_SOC_DAPM_MIXER("Mic Preamp Right", CS42L51_MIC_POWER_CTL, 3, 1, NULL, 0), /* HP */ SND_SOC_DAPM_OUTPUT("HPL"), SND_SOC_DAPM_OUTPUT("HPR"), /* mux */ SND_SOC_DAPM_MUX("DAC Mux", SND_SOC_NOPM, 0, 0, &cs42l51_dac_mux_controls), SND_SOC_DAPM_MUX("PGA-ADC Mux Left", SND_SOC_NOPM, 0, 0, &cs42l51_adcl_mux_controls), SND_SOC_DAPM_MUX("PGA-ADC Mux Right", SND_SOC_NOPM, 0, 0, &cs42l51_adcr_mux_controls), }; static const struct snd_soc_dapm_route cs42l51_routes[] = { {"HPL", NULL, "Left DAC"}, {"HPR", NULL, "Right DAC"}, {"Left ADC", NULL, "Left PGA"}, {"Right ADC", NULL, "Right PGA"}, {"Mic Preamp Left", NULL, "MICL"}, {"Mic Preamp Right", NULL, "MICR"}, {"PGA-ADC Mux Left", "AIN1 Left", "AIN1L" }, {"PGA-ADC Mux Left", "AIN2 Left", "AIN2L" }, {"PGA-ADC Mux Left", "MIC Left", "MICL" }, {"PGA-ADC Mux Left", "MIC+preamp Left", "Mic Preamp Left" }, {"PGA-ADC Mux Right", "AIN1 Right", "AIN1R" }, {"PGA-ADC Mux Right", "AIN2 Right", "AIN2R" }, {"PGA-ADC Mux Right", "MIC Right", "MICR" }, {"PGA-ADC Mux Right", "MIC+preamp Right", "Mic Preamp Right" }, {"Left PGA", NULL, "PGA-ADC Mux Left"}, {"Right PGA", NULL, "PGA-ADC Mux Right"}, }; static int cs42l51_set_dai_fmt(struct snd_soc_dai *codec_dai, unsigned int format) { struct snd_soc_codec *codec = codec_dai->codec; struct cs42l51_private *cs42l51 = snd_soc_codec_get_drvdata(codec); int ret = 0; switch (format & SND_SOC_DAIFMT_FORMAT_MASK) { case SND_SOC_DAIFMT_I2S: case SND_SOC_DAIFMT_LEFT_J: case SND_SOC_DAIFMT_RIGHT_J: cs42l51->audio_mode = format & SND_SOC_DAIFMT_FORMAT_MASK; break; default: dev_err(codec->dev, "invalid DAI format\n"); ret = -EINVAL; } switch (format & SND_SOC_DAIFMT_MASTER_MASK) { case SND_SOC_DAIFMT_CBM_CFM: cs42l51->func = MODE_MASTER; break; case SND_SOC_DAIFMT_CBS_CFS: cs42l51->func = MODE_SLAVE_AUTO; break; default: ret = -EINVAL; break; } return ret; } struct cs42l51_ratios { unsigned int ratio; unsigned char speed_mode; unsigned char mclk; }; static struct cs42l51_ratios slave_ratios[] = { { 512, CS42L51_QSM_MODE, 0 }, { 768, CS42L51_QSM_MODE, 0 }, { 1024, CS42L51_QSM_MODE, 0 }, { 1536, CS42L51_QSM_MODE, 0 }, { 2048, CS42L51_QSM_MODE, 0 }, { 3072, CS42L51_QSM_MODE, 0 }, { 256, CS42L51_HSM_MODE, 0 }, { 384, CS42L51_HSM_MODE, 0 }, { 512, CS42L51_HSM_MODE, 0 }, { 768, CS42L51_HSM_MODE, 0 }, { 1024, CS42L51_HSM_MODE, 0 }, { 1536, CS42L51_HSM_MODE, 0 }, { 128, CS42L51_SSM_MODE, 0 }, { 192, CS42L51_SSM_MODE, 0 }, { 256, CS42L51_SSM_MODE, 0 }, { 384, CS42L51_SSM_MODE, 0 }, { 512, CS42L51_SSM_MODE, 0 }, { 768, CS42L51_SSM_MODE, 0 }, { 128, CS42L51_DSM_MODE, 0 }, { 192, CS42L51_DSM_MODE, 0 }, { 256, CS42L51_DSM_MODE, 0 }, { 384, CS42L51_DSM_MODE, 0 }, }; static struct cs42l51_ratios slave_auto_ratios[] = { { 1024, CS42L51_QSM_MODE, 0 }, { 1536, CS42L51_QSM_MODE, 0 }, { 2048, CS42L51_QSM_MODE, 1 }, { 3072, CS42L51_QSM_MODE, 1 }, { 512, CS42L51_HSM_MODE, 0 }, { 768, CS42L51_HSM_MODE, 0 }, { 1024, CS42L51_HSM_MODE, 1 }, { 1536, CS42L51_HSM_MODE, 1 }, { 256, CS42L51_SSM_MODE, 0 }, { 384, CS42L51_SSM_MODE, 0 }, { 512, CS42L51_SSM_MODE, 1 }, { 768, CS42L51_SSM_MODE, 1 }, { 128, CS42L51_DSM_MODE, 0 }, { 192, CS42L51_DSM_MODE, 0 }, { 256, CS42L51_DSM_MODE, 1 }, { 384, CS42L51_DSM_MODE, 1 }, }; static int cs42l51_set_dai_sysclk(struct snd_soc_dai *codec_dai, int clk_id, unsigned int freq, int dir) { struct snd_soc_codec *codec = codec_dai->codec; struct cs42l51_private *cs42l51 = snd_soc_codec_get_drvdata(codec); cs42l51->mclk = freq; return 0; } static int cs42l51_hw_params(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *params, struct snd_soc_dai *dai) { struct snd_soc_pcm_runtime *rtd = substream->private_data; struct snd_soc_codec *codec = rtd->codec; struct cs42l51_private *cs42l51 = snd_soc_codec_get_drvdata(codec); int ret; unsigned int i; unsigned int rate; unsigned int ratio; struct cs42l51_ratios *ratios = NULL; int nr_ratios = 0; int intf_ctl, power_ctl, fmt; switch (cs42l51->func) { case MODE_MASTER: return -EINVAL; case MODE_SLAVE: ratios = slave_ratios; nr_ratios = ARRAY_SIZE(slave_ratios); break; case MODE_SLAVE_AUTO: ratios = slave_auto_ratios; nr_ratios = ARRAY_SIZE(slave_auto_ratios); break; } /* Figure out which MCLK/LRCK ratio to use */ rate = params_rate(params); /* Sampling rate, in Hz */ ratio = cs42l51->mclk / rate; /* MCLK/LRCK ratio */ for (i = 0; i < nr_ratios; i++) { if (ratios[i].ratio == ratio) break; } if (i == nr_ratios) { /* We did not find a matching ratio */ dev_err(codec->dev, "could not find matching ratio\n"); return -EINVAL; } intf_ctl = snd_soc_read(codec, CS42L51_INTF_CTL); power_ctl = snd_soc_read(codec, CS42L51_MIC_POWER_CTL); intf_ctl &= ~(CS42L51_INTF_CTL_MASTER | CS42L51_INTF_CTL_ADC_I2S | CS42L51_INTF_CTL_DAC_FORMAT(7)); power_ctl &= ~(CS42L51_MIC_POWER_CTL_SPEED(3) | CS42L51_MIC_POWER_CTL_MCLK_DIV2); switch (cs42l51->func) { case MODE_MASTER: intf_ctl |= CS42L51_INTF_CTL_MASTER; power_ctl |= CS42L51_MIC_POWER_CTL_SPEED(ratios[i].speed_mode); break; case MODE_SLAVE: power_ctl |= CS42L51_MIC_POWER_CTL_SPEED(ratios[i].speed_mode); break; case MODE_SLAVE_AUTO: power_ctl |= CS42L51_MIC_POWER_CTL_AUTO; break; } switch (cs42l51->audio_mode) { case SND_SOC_DAIFMT_I2S: intf_ctl |= CS42L51_INTF_CTL_ADC_I2S; intf_ctl |= CS42L51_INTF_CTL_DAC_FORMAT(CS42L51_DAC_DIF_I2S); break; case SND_SOC_DAIFMT_LEFT_J: intf_ctl |= CS42L51_INTF_CTL_DAC_FORMAT(CS42L51_DAC_DIF_LJ24); break; case SND_SOC_DAIFMT_RIGHT_J: switch (params_format(params)) { case SNDRV_PCM_FORMAT_S16_LE: case SNDRV_PCM_FORMAT_S16_BE: fmt = CS42L51_DAC_DIF_RJ16; break; case SNDRV_PCM_FORMAT_S18_3LE: case SNDRV_PCM_FORMAT_S18_3BE: fmt = CS42L51_DAC_DIF_RJ18; break; case SNDRV_PCM_FORMAT_S20_3LE: case SNDRV_PCM_FORMAT_S20_3BE: fmt = CS42L51_DAC_DIF_RJ20; break; case SNDRV_PCM_FORMAT_S24_LE: case SNDRV_PCM_FORMAT_S24_BE: fmt = CS42L51_DAC_DIF_RJ24; break; default: dev_err(codec->dev, "unknown format\n"); return -EINVAL; } intf_ctl |= CS42L51_INTF_CTL_DAC_FORMAT(fmt); break; default: dev_err(codec->dev, "unknown format\n"); return -EINVAL; } if (ratios[i].mclk) power_ctl |= CS42L51_MIC_POWER_CTL_MCLK_DIV2; ret = snd_soc_write(codec, CS42L51_INTF_CTL, intf_ctl); if (ret < 0) return ret; ret = snd_soc_write(codec, CS42L51_MIC_POWER_CTL, power_ctl); if (ret < 0) return ret; return 0; } static int cs42l51_dai_mute(struct snd_soc_dai *dai, int mute) { struct snd_soc_codec *codec = dai->codec; int reg; int mask = CS42L51_DAC_OUT_CTL_DACA_MUTE|CS42L51_DAC_OUT_CTL_DACB_MUTE; reg = snd_soc_read(codec, CS42L51_DAC_OUT_CTL); if (mute) reg |= mask; else reg &= ~mask; return snd_soc_write(codec, CS42L51_DAC_OUT_CTL, reg); } static struct snd_soc_dai_ops cs42l51_dai_ops = { .hw_params = cs42l51_hw_params, .set_sysclk = cs42l51_set_dai_sysclk, .set_fmt = cs42l51_set_dai_fmt, .digital_mute = cs42l51_dai_mute, }; static struct snd_soc_dai_driver cs42l51_dai = { .name = "cs42l51-hifi", .playback = { .stream_name = "Playback", .channels_min = 1, .channels_max = 2, .rates = SNDRV_PCM_RATE_8000_96000, .formats = CS42L51_FORMATS, }, .capture = { .stream_name = "Capture", .channels_min = 1, .channels_max = 2, .rates = SNDRV_PCM_RATE_8000_96000, .formats = CS42L51_FORMATS, }, .ops = &cs42l51_dai_ops, }; static int cs42l51_probe(struct snd_soc_codec *codec) { struct cs42l51_private *cs42l51 = snd_soc_codec_get_drvdata(codec); struct snd_soc_dapm_context *dapm = &codec->dapm; int ret, reg; codec->control_data = cs42l51->control_data; ret = cs42l51_fill_cache(codec); if (ret < 0) { dev_err(codec->dev, "failed to fill register cache\n"); return ret; } ret = snd_soc_codec_set_cache_io(codec, 8, 8, cs42l51->control_type); if (ret < 0) { dev_err(codec->dev, "Failed to set cache I/O: %d\n", ret); return ret; } /* * DAC configuration * - Use signal processor * - auto mute * - vol changes immediate * - no de-emphasize */ reg = CS42L51_DAC_CTL_DATA_SEL(1) | CS42L51_DAC_CTL_AMUTE | CS42L51_DAC_CTL_DACSZ(0); ret = snd_soc_write(codec, CS42L51_DAC_CTL, reg); if (ret < 0) return ret; snd_soc_add_controls(codec, cs42l51_snd_controls, ARRAY_SIZE(cs42l51_snd_controls)); snd_soc_dapm_new_controls(dapm, cs42l51_dapm_widgets, ARRAY_SIZE(cs42l51_dapm_widgets)); snd_soc_dapm_add_routes(dapm, cs42l51_routes, ARRAY_SIZE(cs42l51_routes)); return 0; } static struct snd_soc_codec_driver soc_codec_device_cs42l51 = { .probe = cs42l51_probe, .reg_cache_size = CS42L51_NUMREGS, .reg_word_size = sizeof(u8), }; static int cs42l51_i2c_probe(struct i2c_client *i2c_client, const struct i2c_device_id *id) { struct cs42l51_private *cs42l51; int ret; /* Verify that we have a CS42L51 */ ret = i2c_smbus_read_byte_data(i2c_client, CS42L51_CHIP_REV_ID); if (ret < 0) { dev_err(&i2c_client->dev, "failed to read I2C\n"); goto error; } if ((ret != CS42L51_MK_CHIP_REV(CS42L51_CHIP_ID, CS42L51_CHIP_REV_A)) && (ret != CS42L51_MK_CHIP_REV(CS42L51_CHIP_ID, CS42L51_CHIP_REV_B))) { dev_err(&i2c_client->dev, "Invalid chip id\n"); ret = -ENODEV; goto error; } dev_info(&i2c_client->dev, "found device cs42l51 rev %d\n", ret & 7); cs42l51 = kzalloc(sizeof(struct cs42l51_private), GFP_KERNEL); if (!cs42l51) { dev_err(&i2c_client->dev, "could not allocate codec\n"); return -ENOMEM; } i2c_set_clientdata(i2c_client, cs42l51); cs42l51->control_data = i2c_client; cs42l51->control_type = SND_SOC_I2C; ret = snd_soc_register_codec(&i2c_client->dev, &soc_codec_device_cs42l51, &cs42l51_dai, 1); if (ret < 0) kfree(cs42l51); error: return ret; } static int cs42l51_i2c_remove(struct i2c_client *client) { struct cs42l51_private *cs42l51 = i2c_get_clientdata(client); snd_soc_unregister_codec(&client->dev); kfree(cs42l51); return 0; } static const struct i2c_device_id cs42l51_id[] = { {"cs42l51", 0}, {} }; MODULE_DEVICE_TABLE(i2c, cs42l51_id); static struct i2c_driver cs42l51_i2c_driver = { .driver = { .name = "cs42l51-codec", .owner = THIS_MODULE, }, .id_table = cs42l51_id, .probe = cs42l51_i2c_probe, .remove = cs42l51_i2c_remove, }; static int __init cs42l51_init(void) { int ret; ret = i2c_add_driver(&cs42l51_i2c_driver); if (ret != 0) { printk(KERN_ERR "%s: can't add i2c driver\n", __func__); return ret; } return 0; } module_init(cs42l51_init); static void __exit cs42l51_exit(void) { i2c_del_driver(&cs42l51_i2c_driver); } module_exit(cs42l51_exit); MODULE_AUTHOR("Arnaud Patard "); MODULE_DESCRIPTION("Cirrus Logic CS42L51 ALSA SoC Codec Driver"); MODULE_LICENSE("GPL");