|  | /* | 
|  | * wm8741.c  --  WM8741 ALSA SoC Audio driver | 
|  | * | 
|  | * Copyright 2010 Wolfson Microelectronics plc | 
|  | * | 
|  | * Author: Ian Lartey <ian@opensource.wolfsonmicro.com> | 
|  | * | 
|  | * | 
|  | * 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. | 
|  | */ | 
|  |  | 
|  | #include <linux/module.h> | 
|  | #include <linux/moduleparam.h> | 
|  | #include <linux/init.h> | 
|  | #include <linux/delay.h> | 
|  | #include <linux/pm.h> | 
|  | #include <linux/i2c.h> | 
|  | #include <linux/platform_device.h> | 
|  | #include <linux/regulator/consumer.h> | 
|  | #include <linux/slab.h> | 
|  | #include <sound/core.h> | 
|  | #include <sound/pcm.h> | 
|  | #include <sound/pcm_params.h> | 
|  | #include <sound/soc.h> | 
|  | #include <sound/initval.h> | 
|  | #include <sound/tlv.h> | 
|  |  | 
|  | #include "wm8741.h" | 
|  |  | 
|  | #define WM8741_NUM_SUPPLIES 2 | 
|  | static const char *wm8741_supply_names[WM8741_NUM_SUPPLIES] = { | 
|  | "AVDD", | 
|  | "DVDD", | 
|  | }; | 
|  |  | 
|  | #define WM8741_NUM_RATES 6 | 
|  |  | 
|  | /* codec private data */ | 
|  | struct wm8741_priv { | 
|  | enum snd_soc_control_type control_type; | 
|  | struct regulator_bulk_data supplies[WM8741_NUM_SUPPLIES]; | 
|  | unsigned int sysclk; | 
|  | struct snd_pcm_hw_constraint_list *sysclk_constraints; | 
|  | }; | 
|  |  | 
|  | static const u16 wm8741_reg_defaults[WM8741_REGISTER_COUNT] = { | 
|  | 0x0000,     /* R0  - DACLLSB Attenuation */ | 
|  | 0x0000,     /* R1  - DACLMSB Attenuation */ | 
|  | 0x0000,     /* R2  - DACRLSB Attenuation */ | 
|  | 0x0000,     /* R3  - DACRMSB Attenuation */ | 
|  | 0x0000,     /* R4  - Volume Control */ | 
|  | 0x000A,     /* R5  - Format Control */ | 
|  | 0x0000,     /* R6  - Filter Control */ | 
|  | 0x0000,     /* R7  - Mode Control 1 */ | 
|  | 0x0002,     /* R8  - Mode Control 2 */ | 
|  | 0x0000,	    /* R9  - Reset */ | 
|  | 0x0002,     /* R32 - ADDITONAL_CONTROL_1 */ | 
|  | }; | 
|  |  | 
|  |  | 
|  | static int wm8741_reset(struct snd_soc_codec *codec) | 
|  | { | 
|  | return snd_soc_write(codec, WM8741_RESET, 0); | 
|  | } | 
|  |  | 
|  | static const DECLARE_TLV_DB_SCALE(dac_tlv_fine, -12700, 13, 0); | 
|  | static const DECLARE_TLV_DB_SCALE(dac_tlv, -12700, 400, 0); | 
|  |  | 
|  | static const struct snd_kcontrol_new wm8741_snd_controls[] = { | 
|  | SOC_DOUBLE_R_TLV("Fine Playback Volume", WM8741_DACLLSB_ATTENUATION, | 
|  | WM8741_DACRLSB_ATTENUATION, 1, 255, 1, dac_tlv_fine), | 
|  | SOC_DOUBLE_R_TLV("Playback Volume", WM8741_DACLMSB_ATTENUATION, | 
|  | WM8741_DACRMSB_ATTENUATION, 0, 511, 1, dac_tlv), | 
|  | }; | 
|  |  | 
|  | static const struct snd_soc_dapm_widget wm8741_dapm_widgets[] = { | 
|  | SND_SOC_DAPM_DAC("DACL", "Playback", SND_SOC_NOPM, 0, 0), | 
|  | SND_SOC_DAPM_DAC("DACR", "Playback", SND_SOC_NOPM, 0, 0), | 
|  | SND_SOC_DAPM_OUTPUT("VOUTLP"), | 
|  | SND_SOC_DAPM_OUTPUT("VOUTLN"), | 
|  | SND_SOC_DAPM_OUTPUT("VOUTRP"), | 
|  | SND_SOC_DAPM_OUTPUT("VOUTRN"), | 
|  | }; | 
|  |  | 
|  | static const struct snd_soc_dapm_route intercon[] = { | 
|  | { "VOUTLP", NULL, "DACL" }, | 
|  | { "VOUTLN", NULL, "DACL" }, | 
|  | { "VOUTRP", NULL, "DACR" }, | 
|  | { "VOUTRN", NULL, "DACR" }, | 
|  | }; | 
|  |  | 
|  | static int wm8741_add_widgets(struct snd_soc_codec *codec) | 
|  | { | 
|  | struct snd_soc_dapm_context *dapm = &codec->dapm; | 
|  |  | 
|  | snd_soc_dapm_new_controls(dapm, wm8741_dapm_widgets, | 
|  | ARRAY_SIZE(wm8741_dapm_widgets)); | 
|  | snd_soc_dapm_add_routes(dapm, intercon, ARRAY_SIZE(intercon)); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static struct { | 
|  | int value; | 
|  | int ratio; | 
|  | } lrclk_ratios[WM8741_NUM_RATES] = { | 
|  | { 1, 128 }, | 
|  | { 2, 192 }, | 
|  | { 3, 256 }, | 
|  | { 4, 384 }, | 
|  | { 5, 512 }, | 
|  | { 6, 768 }, | 
|  | }; | 
|  |  | 
|  | static unsigned int rates_11289[] = { | 
|  | 44100, 88235, | 
|  | }; | 
|  |  | 
|  | static struct snd_pcm_hw_constraint_list constraints_11289 = { | 
|  | .count	= ARRAY_SIZE(rates_11289), | 
|  | .list	= rates_11289, | 
|  | }; | 
|  |  | 
|  | static unsigned int rates_12288[] = { | 
|  | 32000, 48000, 96000, | 
|  | }; | 
|  |  | 
|  | static struct snd_pcm_hw_constraint_list constraints_12288 = { | 
|  | .count	= ARRAY_SIZE(rates_12288), | 
|  | .list	= rates_12288, | 
|  | }; | 
|  |  | 
|  | static unsigned int rates_16384[] = { | 
|  | 32000, | 
|  | }; | 
|  |  | 
|  | static struct snd_pcm_hw_constraint_list constraints_16384 = { | 
|  | .count	= ARRAY_SIZE(rates_16384), | 
|  | .list	= rates_16384, | 
|  | }; | 
|  |  | 
|  | static unsigned int rates_16934[] = { | 
|  | 44100, 88235, | 
|  | }; | 
|  |  | 
|  | static struct snd_pcm_hw_constraint_list constraints_16934 = { | 
|  | .count	= ARRAY_SIZE(rates_16934), | 
|  | .list	= rates_16934, | 
|  | }; | 
|  |  | 
|  | static unsigned int rates_18432[] = { | 
|  | 48000, 96000, | 
|  | }; | 
|  |  | 
|  | static struct snd_pcm_hw_constraint_list constraints_18432 = { | 
|  | .count	= ARRAY_SIZE(rates_18432), | 
|  | .list	= rates_18432, | 
|  | }; | 
|  |  | 
|  | static unsigned int rates_22579[] = { | 
|  | 44100, 88235, 1764000 | 
|  | }; | 
|  |  | 
|  | static struct snd_pcm_hw_constraint_list constraints_22579 = { | 
|  | .count	= ARRAY_SIZE(rates_22579), | 
|  | .list	= rates_22579, | 
|  | }; | 
|  |  | 
|  | static unsigned int rates_24576[] = { | 
|  | 32000, 48000, 96000, 192000 | 
|  | }; | 
|  |  | 
|  | static struct snd_pcm_hw_constraint_list constraints_24576 = { | 
|  | .count	= ARRAY_SIZE(rates_24576), | 
|  | .list	= rates_24576, | 
|  | }; | 
|  |  | 
|  | static unsigned int rates_36864[] = { | 
|  | 48000, 96000, 19200 | 
|  | }; | 
|  |  | 
|  | static struct snd_pcm_hw_constraint_list constraints_36864 = { | 
|  | .count	= ARRAY_SIZE(rates_36864), | 
|  | .list	= rates_36864, | 
|  | }; | 
|  |  | 
|  |  | 
|  | static int wm8741_startup(struct snd_pcm_substream *substream, | 
|  | struct snd_soc_dai *dai) | 
|  | { | 
|  | struct snd_soc_codec *codec = dai->codec; | 
|  | struct wm8741_priv *wm8741 = snd_soc_codec_get_drvdata(codec); | 
|  |  | 
|  | /* The set of sample rates that can be supported depends on the | 
|  | * MCLK supplied to the CODEC - enforce this. | 
|  | */ | 
|  | if (!wm8741->sysclk) { | 
|  | dev_err(codec->dev, | 
|  | "No MCLK configured, call set_sysclk() on init\n"); | 
|  | return -EINVAL; | 
|  | } | 
|  |  | 
|  | snd_pcm_hw_constraint_list(substream->runtime, 0, | 
|  | SNDRV_PCM_HW_PARAM_RATE, | 
|  | wm8741->sysclk_constraints); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int wm8741_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 wm8741_priv *wm8741 = snd_soc_codec_get_drvdata(codec); | 
|  | u16 iface = snd_soc_read(codec, WM8741_FORMAT_CONTROL) & 0x1FC; | 
|  | int i; | 
|  |  | 
|  | /* Find a supported LRCLK ratio */ | 
|  | for (i = 0; i < ARRAY_SIZE(lrclk_ratios); i++) { | 
|  | if (wm8741->sysclk / params_rate(params) == | 
|  | lrclk_ratios[i].ratio) | 
|  | break; | 
|  | } | 
|  |  | 
|  | /* Should never happen, should be handled by constraints */ | 
|  | if (i == ARRAY_SIZE(lrclk_ratios)) { | 
|  | dev_err(codec->dev, "MCLK/fs ratio %d unsupported\n", | 
|  | wm8741->sysclk / params_rate(params)); | 
|  | return -EINVAL; | 
|  | } | 
|  |  | 
|  | /* bit size */ | 
|  | switch (params_format(params)) { | 
|  | case SNDRV_PCM_FORMAT_S16_LE: | 
|  | break; | 
|  | case SNDRV_PCM_FORMAT_S20_3LE: | 
|  | iface |= 0x0001; | 
|  | break; | 
|  | case SNDRV_PCM_FORMAT_S24_LE: | 
|  | iface |= 0x0002; | 
|  | break; | 
|  | case SNDRV_PCM_FORMAT_S32_LE: | 
|  | iface |= 0x0003; | 
|  | break; | 
|  | default: | 
|  | dev_dbg(codec->dev, "wm8741_hw_params:    Unsupported bit size param = %d", | 
|  | params_format(params)); | 
|  | return -EINVAL; | 
|  | } | 
|  |  | 
|  | dev_dbg(codec->dev, "wm8741_hw_params:    bit size param = %d", | 
|  | params_format(params)); | 
|  |  | 
|  | snd_soc_write(codec, WM8741_FORMAT_CONTROL, iface); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int wm8741_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 wm8741_priv *wm8741 = snd_soc_codec_get_drvdata(codec); | 
|  |  | 
|  | dev_dbg(codec->dev, "wm8741_set_dai_sysclk info: freq=%dHz\n", freq); | 
|  |  | 
|  | switch (freq) { | 
|  | case 11289600: | 
|  | wm8741->sysclk_constraints = &constraints_11289; | 
|  | wm8741->sysclk = freq; | 
|  | return 0; | 
|  |  | 
|  | case 12288000: | 
|  | wm8741->sysclk_constraints = &constraints_12288; | 
|  | wm8741->sysclk = freq; | 
|  | return 0; | 
|  |  | 
|  | case 16384000: | 
|  | wm8741->sysclk_constraints = &constraints_16384; | 
|  | wm8741->sysclk = freq; | 
|  | return 0; | 
|  |  | 
|  | case 16934400: | 
|  | wm8741->sysclk_constraints = &constraints_16934; | 
|  | wm8741->sysclk = freq; | 
|  | return 0; | 
|  |  | 
|  | case 18432000: | 
|  | wm8741->sysclk_constraints = &constraints_18432; | 
|  | wm8741->sysclk = freq; | 
|  | return 0; | 
|  |  | 
|  | case 22579200: | 
|  | case 33868800: | 
|  | wm8741->sysclk_constraints = &constraints_22579; | 
|  | wm8741->sysclk = freq; | 
|  | return 0; | 
|  |  | 
|  | case 24576000: | 
|  | wm8741->sysclk_constraints = &constraints_24576; | 
|  | wm8741->sysclk = freq; | 
|  | return 0; | 
|  |  | 
|  | case 36864000: | 
|  | wm8741->sysclk_constraints = &constraints_36864; | 
|  | wm8741->sysclk = freq; | 
|  | return 0; | 
|  | } | 
|  | return -EINVAL; | 
|  | } | 
|  |  | 
|  | static int wm8741_set_dai_fmt(struct snd_soc_dai *codec_dai, | 
|  | unsigned int fmt) | 
|  | { | 
|  | struct snd_soc_codec *codec = codec_dai->codec; | 
|  | u16 iface = snd_soc_read(codec, WM8741_FORMAT_CONTROL) & 0x1C3; | 
|  |  | 
|  | /* check master/slave audio interface */ | 
|  | switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) { | 
|  | case SND_SOC_DAIFMT_CBS_CFS: | 
|  | break; | 
|  | default: | 
|  | return -EINVAL; | 
|  | } | 
|  |  | 
|  | /* interface format */ | 
|  | switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) { | 
|  | case SND_SOC_DAIFMT_I2S: | 
|  | iface |= 0x0008; | 
|  | break; | 
|  | case SND_SOC_DAIFMT_RIGHT_J: | 
|  | break; | 
|  | case SND_SOC_DAIFMT_LEFT_J: | 
|  | iface |= 0x0004; | 
|  | break; | 
|  | case SND_SOC_DAIFMT_DSP_A: | 
|  | iface |= 0x0003; | 
|  | break; | 
|  | case SND_SOC_DAIFMT_DSP_B: | 
|  | iface |= 0x0013; | 
|  | break; | 
|  | default: | 
|  | return -EINVAL; | 
|  | } | 
|  |  | 
|  | /* clock inversion */ | 
|  | switch (fmt & SND_SOC_DAIFMT_INV_MASK) { | 
|  | case SND_SOC_DAIFMT_NB_NF: | 
|  | break; | 
|  | case SND_SOC_DAIFMT_IB_IF: | 
|  | iface |= 0x0010; | 
|  | break; | 
|  | case SND_SOC_DAIFMT_IB_NF: | 
|  | iface |= 0x0020; | 
|  | break; | 
|  | case SND_SOC_DAIFMT_NB_IF: | 
|  | iface |= 0x0030; | 
|  | break; | 
|  | default: | 
|  | return -EINVAL; | 
|  | } | 
|  |  | 
|  |  | 
|  | dev_dbg(codec->dev, "wm8741_set_dai_fmt:    Format=%x, Clock Inv=%x\n", | 
|  | fmt & SND_SOC_DAIFMT_FORMAT_MASK, | 
|  | ((fmt & SND_SOC_DAIFMT_INV_MASK))); | 
|  |  | 
|  | snd_soc_write(codec, WM8741_FORMAT_CONTROL, iface); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | #define WM8741_RATES (SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 | \ | 
|  | SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_88200 | \ | 
|  | SNDRV_PCM_RATE_96000 | SNDRV_PCM_RATE_176400 | \ | 
|  | SNDRV_PCM_RATE_192000) | 
|  |  | 
|  | #define WM8741_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S20_3LE |\ | 
|  | SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S32_LE) | 
|  |  | 
|  | static struct snd_soc_dai_ops wm8741_dai_ops = { | 
|  | .startup	= wm8741_startup, | 
|  | .hw_params	= wm8741_hw_params, | 
|  | .set_sysclk	= wm8741_set_dai_sysclk, | 
|  | .set_fmt	= wm8741_set_dai_fmt, | 
|  | }; | 
|  |  | 
|  | static struct snd_soc_dai_driver wm8741_dai = { | 
|  | .name = "wm8741", | 
|  | .playback = { | 
|  | .stream_name = "Playback", | 
|  | .channels_min = 2,  /* Mono modes not yet supported */ | 
|  | .channels_max = 2, | 
|  | .rates = WM8741_RATES, | 
|  | .formats = WM8741_FORMATS, | 
|  | }, | 
|  | .ops = &wm8741_dai_ops, | 
|  | }; | 
|  |  | 
|  | #ifdef CONFIG_PM | 
|  | static int wm8741_resume(struct snd_soc_codec *codec) | 
|  | { | 
|  | u16 *cache = codec->reg_cache; | 
|  | int i; | 
|  |  | 
|  | /* RESTORE REG Cache */ | 
|  | for (i = 0; i < WM8741_REGISTER_COUNT; i++) { | 
|  | if (cache[i] == wm8741_reg_defaults[i] || WM8741_RESET == i) | 
|  | continue; | 
|  | snd_soc_write(codec, i, cache[i]); | 
|  | } | 
|  | return 0; | 
|  | } | 
|  | #else | 
|  | #define wm8741_suspend NULL | 
|  | #define wm8741_resume NULL | 
|  | #endif | 
|  |  | 
|  | static int wm8741_probe(struct snd_soc_codec *codec) | 
|  | { | 
|  | struct wm8741_priv *wm8741 = snd_soc_codec_get_drvdata(codec); | 
|  | int ret = 0; | 
|  |  | 
|  | ret = snd_soc_codec_set_cache_io(codec, 7, 9, wm8741->control_type); | 
|  | if (ret != 0) { | 
|  | dev_err(codec->dev, "Failed to set cache I/O: %d\n", ret); | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | ret = wm8741_reset(codec); | 
|  | if (ret < 0) { | 
|  | dev_err(codec->dev, "Failed to issue reset\n"); | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | /* Change some default settings - latch VU */ | 
|  | snd_soc_update_bits(codec, WM8741_DACLLSB_ATTENUATION, | 
|  | WM8741_UPDATELL, WM8741_UPDATELL); | 
|  | snd_soc_update_bits(codec, WM8741_DACLMSB_ATTENUATION, | 
|  | WM8741_UPDATELM, WM8741_UPDATELM); | 
|  | snd_soc_update_bits(codec, WM8741_DACRLSB_ATTENUATION, | 
|  | WM8741_UPDATERL, WM8741_UPDATERL); | 
|  | snd_soc_update_bits(codec, WM8741_DACRLSB_ATTENUATION, | 
|  | WM8741_UPDATERM, WM8741_UPDATERM); | 
|  |  | 
|  | snd_soc_add_controls(codec, wm8741_snd_controls, | 
|  | ARRAY_SIZE(wm8741_snd_controls)); | 
|  | wm8741_add_widgets(codec); | 
|  |  | 
|  | dev_dbg(codec->dev, "Successful registration\n"); | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | static struct snd_soc_codec_driver soc_codec_dev_wm8741 = { | 
|  | .probe =	wm8741_probe, | 
|  | .resume =	wm8741_resume, | 
|  | .reg_cache_size = ARRAY_SIZE(wm8741_reg_defaults), | 
|  | .reg_word_size = sizeof(u16), | 
|  | .reg_cache_default = wm8741_reg_defaults, | 
|  | }; | 
|  |  | 
|  | #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) | 
|  | static int wm8741_i2c_probe(struct i2c_client *i2c, | 
|  | const struct i2c_device_id *id) | 
|  | { | 
|  | struct wm8741_priv *wm8741; | 
|  | int ret, i; | 
|  |  | 
|  | wm8741 = kzalloc(sizeof(struct wm8741_priv), GFP_KERNEL); | 
|  | if (wm8741 == NULL) | 
|  | return -ENOMEM; | 
|  |  | 
|  | for (i = 0; i < ARRAY_SIZE(wm8741->supplies); i++) | 
|  | wm8741->supplies[i].supply = wm8741_supply_names[i]; | 
|  |  | 
|  | ret = regulator_bulk_get(&i2c->dev, ARRAY_SIZE(wm8741->supplies), | 
|  | wm8741->supplies); | 
|  | if (ret != 0) { | 
|  | dev_err(&i2c->dev, "Failed to request supplies: %d\n", ret); | 
|  | goto err; | 
|  | } | 
|  |  | 
|  | ret = regulator_bulk_enable(ARRAY_SIZE(wm8741->supplies), | 
|  | wm8741->supplies); | 
|  | if (ret != 0) { | 
|  | dev_err(&i2c->dev, "Failed to enable supplies: %d\n", ret); | 
|  | goto err_get; | 
|  | } | 
|  |  | 
|  | i2c_set_clientdata(i2c, wm8741); | 
|  | wm8741->control_type = SND_SOC_I2C; | 
|  |  | 
|  | ret =  snd_soc_register_codec(&i2c->dev, | 
|  | &soc_codec_dev_wm8741, &wm8741_dai, 1); | 
|  | if (ret < 0) | 
|  | goto err_enable; | 
|  | return ret; | 
|  |  | 
|  | err_enable: | 
|  | regulator_bulk_disable(ARRAY_SIZE(wm8741->supplies), wm8741->supplies); | 
|  |  | 
|  | err_get: | 
|  | regulator_bulk_free(ARRAY_SIZE(wm8741->supplies), wm8741->supplies); | 
|  | err: | 
|  | kfree(wm8741); | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | static int wm8741_i2c_remove(struct i2c_client *client) | 
|  | { | 
|  | struct wm8741_priv *wm8741 = i2c_get_clientdata(client); | 
|  |  | 
|  | snd_soc_unregister_codec(&client->dev); | 
|  | regulator_bulk_free(ARRAY_SIZE(wm8741->supplies), wm8741->supplies); | 
|  | kfree(i2c_get_clientdata(client)); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static const struct i2c_device_id wm8741_i2c_id[] = { | 
|  | { "wm8741", 0 }, | 
|  | { } | 
|  | }; | 
|  | MODULE_DEVICE_TABLE(i2c, wm8741_i2c_id); | 
|  |  | 
|  | static struct i2c_driver wm8741_i2c_driver = { | 
|  | .driver = { | 
|  | .name = "wm8741-codec", | 
|  | .owner = THIS_MODULE, | 
|  | }, | 
|  | .probe =    wm8741_i2c_probe, | 
|  | .remove =   wm8741_i2c_remove, | 
|  | .id_table = wm8741_i2c_id, | 
|  | }; | 
|  | #endif | 
|  |  | 
|  | static int __init wm8741_modinit(void) | 
|  | { | 
|  | int ret = 0; | 
|  |  | 
|  | #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) | 
|  | ret = i2c_add_driver(&wm8741_i2c_driver); | 
|  | if (ret != 0) | 
|  | pr_err("Failed to register WM8741 I2C driver: %d\n", ret); | 
|  | #endif | 
|  |  | 
|  | return ret; | 
|  | } | 
|  | module_init(wm8741_modinit); | 
|  |  | 
|  | static void __exit wm8741_exit(void) | 
|  | { | 
|  | #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) | 
|  | i2c_del_driver(&wm8741_i2c_driver); | 
|  | #endif | 
|  | } | 
|  | module_exit(wm8741_exit); | 
|  |  | 
|  | MODULE_DESCRIPTION("ASoC WM8741 driver"); | 
|  | MODULE_AUTHOR("Ian Lartey <ian@opensource.wolfsonmicro.com>"); | 
|  | MODULE_LICENSE("GPL"); |