Initial import

1 files changed, 1087 insertions, 0 deletions

diff --git a/sound/soc/codecs/wm8978.c b/sound/soc/codecs/wm8978.c
new file mode 100644
index 000000000..cf7032911
--- /dev/null
+++ b/sound/soc/codecs/wm8978.c
@@ -0,0 +1,1087 @@
+/*
+ * wm8978.c  --  WM8978 ALSA SoC Audio Codec driver
+ *
+ * Copyright (C) 2009-2010 Guennadi Liakhovetski <g.liakhovetski@gmx.de>
+ * Copyright (C) 2007 Carlos Munoz <carlos@kenati.com>
+ * Copyright 2006-2009 Wolfson Microelectronics PLC.
+ * Based on wm8974 and wm8990 by Liam Girdwood <lrg@slimlogic.co.uk>
+ *
+ * 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/kernel.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/pm.h>
+#include <linux/i2c.h>
+#include <linux/regmap.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 <asm/div64.h>
+
+#include "wm8978.h"
+
+static const struct reg_default wm8978_reg_defaults[] = {
+	{ 1, 0x0000 },
+	{ 2, 0x0000 },
+	{ 3, 0x0000 },
+	{ 4, 0x0050 },
+	{ 5, 0x0000 },
+	{ 6, 0x0140 },
+	{ 7, 0x0000 },
+	{ 8, 0x0000 },
+	{ 9, 0x0000 },
+	{ 10, 0x0000 },
+	{ 11, 0x00ff },
+	{ 12, 0x00ff },
+	{ 13, 0x0000 },
+	{ 14, 0x0100 },
+	{ 15, 0x00ff },
+	{ 16, 0x00ff },
+	{ 17, 0x0000 },
+	{ 18, 0x012c },
+	{ 19, 0x002c },
+	{ 20, 0x002c },
+	{ 21, 0x002c },
+	{ 22, 0x002c },
+	{ 23, 0x0000 },
+	{ 24, 0x0032 },
+	{ 25, 0x0000 },
+	{ 26, 0x0000 },
+	{ 27, 0x0000 },
+	{ 28, 0x0000 },
+	{ 29, 0x0000 },
+	{ 30, 0x0000 },
+	{ 31, 0x0000 },
+	{ 32, 0x0038 },
+	{ 33, 0x000b },
+	{ 34, 0x0032 },
+	{ 35, 0x0000 },
+	{ 36, 0x0008 },
+	{ 37, 0x000c },
+	{ 38, 0x0093 },
+	{ 39, 0x00e9 },
+	{ 40, 0x0000 },
+	{ 41, 0x0000 },
+	{ 42, 0x0000 },
+	{ 43, 0x0000 },
+	{ 44, 0x0033 },
+	{ 45, 0x0010 },
+	{ 46, 0x0010 },
+	{ 47, 0x0100 },
+	{ 48, 0x0100 },
+	{ 49, 0x0002 },
+	{ 50, 0x0001 },
+	{ 51, 0x0001 },
+	{ 52, 0x0039 },
+	{ 53, 0x0039 },
+	{ 54, 0x0039 },
+	{ 55, 0x0039 },
+	{ 56, 0x0001 },
+	{ 57, 0x0001 },
+};
+
+static bool wm8978_volatile(struct device *dev, unsigned int reg)
+{
+	return reg == WM8978_RESET;
+}
+
+/* codec private data */
+struct wm8978_priv {
+	struct regmap *regmap;
+	unsigned int f_pllout;
+	unsigned int f_mclk;
+	unsigned int f_256fs;
+	unsigned int f_opclk;
+	int mclk_idx;
+	enum wm8978_sysclk_src sysclk;
+};
+
+static const char *wm8978_companding[] = {"Off", "NC", "u-law", "A-law"};
+static const char *wm8978_eqmode[] = {"Capture", "Playback"};
+static const char *wm8978_bw[] = {"Narrow", "Wide"};
+static const char *wm8978_eq1[] = {"80Hz", "105Hz", "135Hz", "175Hz"};
+static const char *wm8978_eq2[] = {"230Hz", "300Hz", "385Hz", "500Hz"};
+static const char *wm8978_eq3[] = {"650Hz", "850Hz", "1.1kHz", "1.4kHz"};
+static const char *wm8978_eq4[] = {"1.8kHz", "2.4kHz", "3.2kHz", "4.1kHz"};
+static const char *wm8978_eq5[] = {"5.3kHz", "6.9kHz", "9kHz", "11.7kHz"};
+static const char *wm8978_alc3[] = {"ALC", "Limiter"};
+static const char *wm8978_alc1[] = {"Off", "Right", "Left", "Both"};
+
+static SOC_ENUM_SINGLE_DECL(adc_compand, WM8978_COMPANDING_CONTROL, 1,
+			    wm8978_companding);
+static SOC_ENUM_SINGLE_DECL(dac_compand, WM8978_COMPANDING_CONTROL, 3,
+			    wm8978_companding);
+static SOC_ENUM_SINGLE_DECL(eqmode, WM8978_EQ1, 8, wm8978_eqmode);
+static SOC_ENUM_SINGLE_DECL(eq1, WM8978_EQ1, 5, wm8978_eq1);
+static SOC_ENUM_SINGLE_DECL(eq2bw, WM8978_EQ2, 8, wm8978_bw);
+static SOC_ENUM_SINGLE_DECL(eq2, WM8978_EQ2, 5, wm8978_eq2);
+static SOC_ENUM_SINGLE_DECL(eq3bw, WM8978_EQ3, 8, wm8978_bw);
+static SOC_ENUM_SINGLE_DECL(eq3, WM8978_EQ3, 5, wm8978_eq3);
+static SOC_ENUM_SINGLE_DECL(eq4bw, WM8978_EQ4, 8, wm8978_bw);
+static SOC_ENUM_SINGLE_DECL(eq4, WM8978_EQ4, 5, wm8978_eq4);
+static SOC_ENUM_SINGLE_DECL(eq5, WM8978_EQ5, 5, wm8978_eq5);
+static SOC_ENUM_SINGLE_DECL(alc3, WM8978_ALC_CONTROL_3, 8, wm8978_alc3);
+static SOC_ENUM_SINGLE_DECL(alc1, WM8978_ALC_CONTROL_1, 7, wm8978_alc1);
+
+static const DECLARE_TLV_DB_SCALE(digital_tlv, -12750, 50, 1);
+static const DECLARE_TLV_DB_SCALE(eq_tlv, -1200, 100, 0);
+static const DECLARE_TLV_DB_SCALE(inpga_tlv, -1200, 75, 0);
+static const DECLARE_TLV_DB_SCALE(spk_tlv, -5700, 100, 0);
+static const DECLARE_TLV_DB_SCALE(boost_tlv, -1500, 300, 1);
+static const DECLARE_TLV_DB_SCALE(limiter_tlv, 0, 100, 0);
+
+static const struct snd_kcontrol_new wm8978_snd_controls[] = {
+
+	SOC_SINGLE("Digital Loopback Switch",
+		WM8978_COMPANDING_CONTROL, 0, 1, 0),
+
+	SOC_ENUM("ADC Companding", adc_compand),
+	SOC_ENUM("DAC Companding", dac_compand),
+
+	SOC_DOUBLE("DAC Inversion Switch", WM8978_DAC_CONTROL, 0, 1, 1, 0),
+
+	SOC_DOUBLE_R_TLV("PCM Volume",
+		WM8978_LEFT_DAC_DIGITAL_VOLUME, WM8978_RIGHT_DAC_DIGITAL_VOLUME,
+		0, 255, 0, digital_tlv),
+
+	SOC_SINGLE("High Pass Filter Switch", WM8978_ADC_CONTROL, 8, 1, 0),
+	SOC_SINGLE("High Pass Cut Off", WM8978_ADC_CONTROL, 4, 7, 0),
+	SOC_DOUBLE("ADC Inversion Switch", WM8978_ADC_CONTROL, 0, 1, 1, 0),
+
+	SOC_DOUBLE_R_TLV("ADC Volume",
+		WM8978_LEFT_ADC_DIGITAL_VOLUME, WM8978_RIGHT_ADC_DIGITAL_VOLUME,
+		0, 255, 0, digital_tlv),
+
+	SOC_ENUM("Equaliser Function", eqmode),
+	SOC_ENUM("EQ1 Cut Off", eq1),
+	SOC_SINGLE_TLV("EQ1 Volume", WM8978_EQ1,  0, 24, 1, eq_tlv),
+
+	SOC_ENUM("Equaliser EQ2 Bandwidth", eq2bw),
+	SOC_ENUM("EQ2 Cut Off", eq2),
+	SOC_SINGLE_TLV("EQ2 Volume", WM8978_EQ2,  0, 24, 1, eq_tlv),
+
+	SOC_ENUM("Equaliser EQ3 Bandwidth", eq3bw),
+	SOC_ENUM("EQ3 Cut Off", eq3),
+	SOC_SINGLE_TLV("EQ3 Volume", WM8978_EQ3,  0, 24, 1, eq_tlv),
+
+	SOC_ENUM("Equaliser EQ4 Bandwidth", eq4bw),
+	SOC_ENUM("EQ4 Cut Off", eq4),
+	SOC_SINGLE_TLV("EQ4 Volume", WM8978_EQ4,  0, 24, 1, eq_tlv),
+
+	SOC_ENUM("EQ5 Cut Off", eq5),
+	SOC_SINGLE_TLV("EQ5 Volume", WM8978_EQ5, 0, 24, 1, eq_tlv),
+
+	SOC_SINGLE("DAC Playback Limiter Switch",
+		WM8978_DAC_LIMITER_1, 8, 1, 0),
+	SOC_SINGLE("DAC Playback Limiter Decay",
+		WM8978_DAC_LIMITER_1, 4, 15, 0),
+	SOC_SINGLE("DAC Playback Limiter Attack",
+		WM8978_DAC_LIMITER_1, 0, 15, 0),
+
+	SOC_SINGLE("DAC Playback Limiter Threshold",
+		WM8978_DAC_LIMITER_2, 4, 7, 0),
+	SOC_SINGLE_TLV("DAC Playback Limiter Volume",
+		WM8978_DAC_LIMITER_2, 0, 12, 0, limiter_tlv),
+
+	SOC_ENUM("ALC Enable Switch", alc1),
+	SOC_SINGLE("ALC Capture Min Gain", WM8978_ALC_CONTROL_1, 0, 7, 0),
+	SOC_SINGLE("ALC Capture Max Gain", WM8978_ALC_CONTROL_1, 3, 7, 0),
+
+	SOC_SINGLE("ALC Capture Hold", WM8978_ALC_CONTROL_2, 4, 10, 0),
+	SOC_SINGLE("ALC Capture Target", WM8978_ALC_CONTROL_2, 0, 15, 0),
+
+	SOC_ENUM("ALC Capture Mode", alc3),
+	SOC_SINGLE("ALC Capture Decay", WM8978_ALC_CONTROL_3, 4, 10, 0),
+	SOC_SINGLE("ALC Capture Attack", WM8978_ALC_CONTROL_3, 0, 10, 0),
+
+	SOC_SINGLE("ALC Capture Noise Gate Switch", WM8978_NOISE_GATE, 3, 1, 0),
+	SOC_SINGLE("ALC Capture Noise Gate Threshold",
+		WM8978_NOISE_GATE, 0, 7, 0),
+
+	SOC_DOUBLE_R("Capture PGA ZC Switch",
+		WM8978_LEFT_INP_PGA_CONTROL, WM8978_RIGHT_INP_PGA_CONTROL,
+		7, 1, 0),
+
+	/* OUT1 - Headphones */
+	SOC_DOUBLE_R("Headphone Playback ZC Switch",
+		WM8978_LOUT1_HP_CONTROL, WM8978_ROUT1_HP_CONTROL, 7, 1, 0),
+
+	SOC_DOUBLE_R_TLV("Headphone Playback Volume",
+		WM8978_LOUT1_HP_CONTROL, WM8978_ROUT1_HP_CONTROL,
+		0, 63, 0, spk_tlv),
+
+	/* OUT2 - Speakers */
+	SOC_DOUBLE_R("Speaker Playback ZC Switch",
+		WM8978_LOUT2_SPK_CONTROL, WM8978_ROUT2_SPK_CONTROL, 7, 1, 0),
+
+	SOC_DOUBLE_R_TLV("Speaker Playback Volume",
+		WM8978_LOUT2_SPK_CONTROL, WM8978_ROUT2_SPK_CONTROL,
+		0, 63, 0, spk_tlv),
+
+	/* OUT3/4 - Line Output */
+	SOC_DOUBLE_R("Line Playback Switch",
+		WM8978_OUT3_MIXER_CONTROL, WM8978_OUT4_MIXER_CONTROL, 6, 1, 1),
+
+	/* Mixer #3: Boost (Input) mixer */
+	SOC_DOUBLE_R("PGA Boost (+20dB)",
+		WM8978_LEFT_ADC_BOOST_CONTROL, WM8978_RIGHT_ADC_BOOST_CONTROL,
+		8, 1, 0),
+	SOC_DOUBLE_R_TLV("L2/R2 Boost Volume",
+		WM8978_LEFT_ADC_BOOST_CONTROL, WM8978_RIGHT_ADC_BOOST_CONTROL,
+		4, 7, 0, boost_tlv),
+	SOC_DOUBLE_R_TLV("Aux Boost Volume",
+		WM8978_LEFT_ADC_BOOST_CONTROL, WM8978_RIGHT_ADC_BOOST_CONTROL,
+		0, 7, 0, boost_tlv),
+
+	/* Input PGA volume */
+	SOC_DOUBLE_R_TLV("Input PGA Volume",
+		WM8978_LEFT_INP_PGA_CONTROL, WM8978_RIGHT_INP_PGA_CONTROL,
+		0, 63, 0, inpga_tlv),
+
+	/* Headphone */
+	SOC_DOUBLE_R("Headphone Switch",
+		WM8978_LOUT1_HP_CONTROL, WM8978_ROUT1_HP_CONTROL, 6, 1, 1),
+
+	/* Speaker */
+	SOC_DOUBLE_R("Speaker Switch",
+		WM8978_LOUT2_SPK_CONTROL, WM8978_ROUT2_SPK_CONTROL, 6, 1, 1),
+
+	/* DAC / ADC oversampling */
+	SOC_SINGLE("DAC 128x Oversampling Switch", WM8978_DAC_CONTROL,
+		   5, 1, 0),
+	SOC_SINGLE("ADC 128x Oversampling Switch", WM8978_ADC_CONTROL,
+		   5, 1, 0),
+};
+
+/* Mixer #1: Output (OUT1, OUT2) Mixer: mix AUX, Input mixer output and DAC */
+static const struct snd_kcontrol_new wm8978_left_out_mixer[] = {
+	SOC_DAPM_SINGLE("Line Bypass Switch", WM8978_LEFT_MIXER_CONTROL, 1, 1, 0),
+	SOC_DAPM_SINGLE("Aux Playback Switch", WM8978_LEFT_MIXER_CONTROL, 5, 1, 0),
+	SOC_DAPM_SINGLE("PCM Playback Switch", WM8978_LEFT_MIXER_CONTROL, 0, 1, 0),
+};
+
+static const struct snd_kcontrol_new wm8978_right_out_mixer[] = {
+	SOC_DAPM_SINGLE("Line Bypass Switch", WM8978_RIGHT_MIXER_CONTROL, 1, 1, 0),
+	SOC_DAPM_SINGLE("Aux Playback Switch", WM8978_RIGHT_MIXER_CONTROL, 5, 1, 0),
+	SOC_DAPM_SINGLE("PCM Playback Switch", WM8978_RIGHT_MIXER_CONTROL, 0, 1, 0),
+};
+
+/* OUT3/OUT4 Mixer not implemented */
+
+/* Mixer #2: Input PGA Mute */
+static const struct snd_kcontrol_new wm8978_left_input_mixer[] = {
+	SOC_DAPM_SINGLE("L2 Switch", WM8978_INPUT_CONTROL, 2, 1, 0),
+	SOC_DAPM_SINGLE("MicN Switch", WM8978_INPUT_CONTROL, 1, 1, 0),
+	SOC_DAPM_SINGLE("MicP Switch", WM8978_INPUT_CONTROL, 0, 1, 0),
+};
+static const struct snd_kcontrol_new wm8978_right_input_mixer[] = {
+	SOC_DAPM_SINGLE("R2 Switch", WM8978_INPUT_CONTROL, 6, 1, 0),
+	SOC_DAPM_SINGLE("MicN Switch", WM8978_INPUT_CONTROL, 5, 1, 0),
+	SOC_DAPM_SINGLE("MicP Switch", WM8978_INPUT_CONTROL, 4, 1, 0),
+};
+
+static const struct snd_soc_dapm_widget wm8978_dapm_widgets[] = {
+	SND_SOC_DAPM_DAC("Left DAC", "Left HiFi Playback",
+			 WM8978_POWER_MANAGEMENT_3, 0, 0),
+	SND_SOC_DAPM_DAC("Right DAC", "Right HiFi Playback",
+			 WM8978_POWER_MANAGEMENT_3, 1, 0),
+	SND_SOC_DAPM_ADC("Left ADC", "Left HiFi Capture",
+			 WM8978_POWER_MANAGEMENT_2, 0, 0),
+	SND_SOC_DAPM_ADC("Right ADC", "Right HiFi Capture",
+			 WM8978_POWER_MANAGEMENT_2, 1, 0),
+
+	/* Mixer #1: OUT1,2 */
+	SOC_MIXER_ARRAY("Left Output Mixer", WM8978_POWER_MANAGEMENT_3,
+			2, 0, wm8978_left_out_mixer),
+	SOC_MIXER_ARRAY("Right Output Mixer", WM8978_POWER_MANAGEMENT_3,
+			3, 0, wm8978_right_out_mixer),
+
+	SOC_MIXER_ARRAY("Left Input Mixer", WM8978_POWER_MANAGEMENT_2,
+			2, 0, wm8978_left_input_mixer),
+	SOC_MIXER_ARRAY("Right Input Mixer", WM8978_POWER_MANAGEMENT_2,
+			3, 0, wm8978_right_input_mixer),
+
+	SND_SOC_DAPM_PGA("Left Boost Mixer", WM8978_POWER_MANAGEMENT_2,
+			 4, 0, NULL, 0),
+	SND_SOC_DAPM_PGA("Right Boost Mixer", WM8978_POWER_MANAGEMENT_2,
+			 5, 0, NULL, 0),
+
+	SND_SOC_DAPM_PGA("Left Capture PGA", WM8978_LEFT_INP_PGA_CONTROL,
+			 6, 1, NULL, 0),
+	SND_SOC_DAPM_PGA("Right Capture PGA", WM8978_RIGHT_INP_PGA_CONTROL,
+			 6, 1, NULL, 0),
+
+	SND_SOC_DAPM_PGA("Left Headphone Out", WM8978_POWER_MANAGEMENT_2,
+			 7, 0, NULL, 0),
+	SND_SOC_DAPM_PGA("Right Headphone Out", WM8978_POWER_MANAGEMENT_2,
+			 8, 0, NULL, 0),
+
+	SND_SOC_DAPM_PGA("Left Speaker Out", WM8978_POWER_MANAGEMENT_3,
+			 6, 0, NULL, 0),
+	SND_SOC_DAPM_PGA("Right Speaker Out", WM8978_POWER_MANAGEMENT_3,
+			 5, 0, NULL, 0),
+
+	SND_SOC_DAPM_MIXER("OUT4 VMID", WM8978_POWER_MANAGEMENT_3,
+			   8, 0, NULL, 0),
+
+	SND_SOC_DAPM_MICBIAS("Mic Bias", WM8978_POWER_MANAGEMENT_1, 4, 0),
+
+	SND_SOC_DAPM_INPUT("LMICN"),
+	SND_SOC_DAPM_INPUT("LMICP"),
+	SND_SOC_DAPM_INPUT("RMICN"),
+	SND_SOC_DAPM_INPUT("RMICP"),
+	SND_SOC_DAPM_INPUT("LAUX"),
+	SND_SOC_DAPM_INPUT("RAUX"),
+	SND_SOC_DAPM_INPUT("L2"),
+	SND_SOC_DAPM_INPUT("R2"),
+	SND_SOC_DAPM_OUTPUT("LHP"),
+	SND_SOC_DAPM_OUTPUT("RHP"),
+	SND_SOC_DAPM_OUTPUT("LSPK"),
+	SND_SOC_DAPM_OUTPUT("RSPK"),
+};
+
+static const struct snd_soc_dapm_route wm8978_dapm_routes[] = {
+	/* Output mixer */
+	{"Right Output Mixer", "PCM Playback Switch", "Right DAC"},
+	{"Right Output Mixer", "Aux Playback Switch", "RAUX"},
+	{"Right Output Mixer", "Line Bypass Switch", "Right Boost Mixer"},
+
+	{"Left Output Mixer", "PCM Playback Switch", "Left DAC"},
+	{"Left Output Mixer", "Aux Playback Switch", "LAUX"},
+	{"Left Output Mixer", "Line Bypass Switch", "Left Boost Mixer"},
+
+	/* Outputs */
+	{"Right Headphone Out", NULL, "Right Output Mixer"},
+	{"RHP", NULL, "Right Headphone Out"},
+
+	{"Left Headphone Out", NULL, "Left Output Mixer"},
+	{"LHP", NULL, "Left Headphone Out"},
+
+	{"Right Speaker Out", NULL, "Right Output Mixer"},
+	{"RSPK", NULL, "Right Speaker Out"},
+
+	{"Left Speaker Out", NULL, "Left Output Mixer"},
+	{"LSPK", NULL, "Left Speaker Out"},
+
+	/* Boost Mixer */
+	{"Right ADC", NULL, "Right Boost Mixer"},
+
+	{"Right Boost Mixer", NULL, "RAUX"},
+	{"Right Boost Mixer", NULL, "Right Capture PGA"},
+	{"Right Boost Mixer", NULL, "R2"},
+
+	{"Left ADC", NULL, "Left Boost Mixer"},
+
+	{"Left Boost Mixer", NULL, "LAUX"},
+	{"Left Boost Mixer", NULL, "Left Capture PGA"},
+	{"Left Boost Mixer", NULL, "L2"},
+
+	/* Input PGA */
+	{"Right Capture PGA", NULL, "Right Input Mixer"},
+	{"Left Capture PGA", NULL, "Left Input Mixer"},
+
+	{"Right Input Mixer", "R2 Switch", "R2"},
+	{"Right Input Mixer", "MicN Switch", "RMICN"},
+	{"Right Input Mixer", "MicP Switch", "RMICP"},
+
+	{"Left Input Mixer", "L2 Switch", "L2"},
+	{"Left Input Mixer", "MicN Switch", "LMICN"},
+	{"Left Input Mixer", "MicP Switch", "LMICP"},
+};
+
+/* PLL divisors */
+struct wm8978_pll_div {
+	u32 k;
+	u8 n;
+	u8 div2;
+};
+
+#define FIXED_PLL_SIZE (1 << 24)
+
+static void pll_factors(struct snd_soc_codec *codec,
+		struct wm8978_pll_div *pll_div, unsigned int target, unsigned int source)
+{
+	u64 k_part;
+	unsigned int k, n_div, n_mod;
+
+	n_div = target / source;
+	if (n_div < 6) {
+		source >>= 1;
+		pll_div->div2 = 1;
+		n_div = target / source;
+	} else {
+		pll_div->div2 = 0;
+	}
+
+	if (n_div < 6 || n_div > 12)
+		dev_warn(codec->dev,
+			 "WM8978 N value exceeds recommended range! N = %u\n",
+			 n_div);
+
+	pll_div->n = n_div;
+	n_mod = target - source * n_div;
+	k_part = FIXED_PLL_SIZE * (long long)n_mod + source / 2;
+
+	do_div(k_part, source);
+
+	k = k_part & 0xFFFFFFFF;
+
+	pll_div->k = k;
+}
+
+/* MCLK dividers */
+static const int mclk_numerator[]	= {1, 3, 2, 3, 4, 6, 8, 12};
+static const int mclk_denominator[]	= {1, 2, 1, 1, 1, 1, 1, 1};
+
+/*
+ * find index >= idx, such that, for a given f_out,
+ * 3 * f_mclk / 4 <= f_PLLOUT < 13 * f_mclk / 4
+ * f_out can be f_256fs or f_opclk, currently only used for f_256fs. Can be
+ * generalised for f_opclk with suitable coefficient arrays, but currently
+ * the OPCLK divisor is calculated directly, not iteratively.
+ */
+static int wm8978_enum_mclk(unsigned int f_out, unsigned int f_mclk,
+			    unsigned int *f_pllout)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(mclk_numerator); i++) {
+		unsigned int f_pllout_x4 = 4 * f_out * mclk_numerator[i] /
+			mclk_denominator[i];
+		if (3 * f_mclk <= f_pllout_x4 && f_pllout_x4 < 13 * f_mclk) {
+			*f_pllout = f_pllout_x4 / 4;
+			return i;
+		}
+	}
+
+	return -EINVAL;
+}
+
+/*
+ * Calculate internal frequencies and dividers, according to Figure 40
+ * "PLL and Clock Select Circuit" in WM8978 datasheet Rev. 2.6
+ */
+static int wm8978_configure_pll(struct snd_soc_codec *codec)
+{
+	struct wm8978_priv *wm8978 = snd_soc_codec_get_drvdata(codec);
+	struct wm8978_pll_div pll_div;
+	unsigned int f_opclk = wm8978->f_opclk, f_mclk = wm8978->f_mclk,
+		f_256fs = wm8978->f_256fs;
+	unsigned int f2;
+
+	if (!f_mclk)
+		return -EINVAL;
+
+	if (f_opclk) {
+		unsigned int opclk_div;
+		/* Cannot set up MCLK divider now, do later */
+		wm8978->mclk_idx = -1;
+
+		/*
+		 * The user needs OPCLK. Choose OPCLKDIV to put
+		 * 6 <= R = f2 / f1 < 13, 1 <= OPCLKDIV <= 4.
+		 * f_opclk = f_mclk * prescale * R / 4 / OPCLKDIV, where
+		 * prescale = 1, or prescale = 2. Prescale is calculated inside
+		 * pll_factors(). We have to select f_PLLOUT, such that
+		 * f_mclk * 3 / 4 <= f_PLLOUT < f_mclk * 13 / 4. Must be
+		 * f_mclk * 3 / 16 <= f_opclk < f_mclk * 13 / 4.
+		 */
+		if (16 * f_opclk < 3 * f_mclk || 4 * f_opclk >= 13 * f_mclk)
+			return -EINVAL;
+
+		if (4 * f_opclk < 3 * f_mclk)
+			/* Have to use OPCLKDIV */
+			opclk_div = (3 * f_mclk / 4 + f_opclk - 1) / f_opclk;
+		else
+			opclk_div = 1;
+
+		dev_dbg(codec->dev, "%s: OPCLKDIV=%d\n", __func__, opclk_div);
+
+		snd_soc_update_bits(codec, WM8978_GPIO_CONTROL, 0x30,
+				    (opclk_div - 1) << 4);
+
+		wm8978->f_pllout = f_opclk * opclk_div;
+	} else if (f_256fs) {
+		/*
+		 * Not using OPCLK, but PLL is used for the codec, choose R:
+		 * 6 <= R = f2 / f1 < 13, to put 1 <= MCLKDIV <= 12.
+		 * f_256fs = f_mclk * prescale * R / 4 / MCLKDIV, where
+		 * prescale = 1, or prescale = 2. Prescale is calculated inside
+		 * pll_factors(). We have to select f_PLLOUT, such that
+		 * f_mclk * 3 / 4 <= f_PLLOUT < f_mclk * 13 / 4. Must be
+		 * f_mclk * 3 / 48 <= f_256fs < f_mclk * 13 / 4. This means MCLK
+		 * must be 3.781MHz <= f_MCLK <= 32.768MHz
+		 */
+		int idx = wm8978_enum_mclk(f_256fs, f_mclk, &wm8978->f_pllout);
+		if (idx < 0)
+			return idx;
+
+		wm8978->mclk_idx = idx;
+	} else {
+		return -EINVAL;
+	}
+
+	f2 = wm8978->f_pllout * 4;
+
+	dev_dbg(codec->dev, "%s: f_MCLK=%uHz, f_PLLOUT=%uHz\n", __func__,
+		wm8978->f_mclk, wm8978->f_pllout);
+
+	pll_factors(codec, &pll_div, f2, wm8978->f_mclk);
+
+	dev_dbg(codec->dev, "%s: calculated PLL N=0x%x, K=0x%x, div2=%d\n",
+		__func__, pll_div.n, pll_div.k, pll_div.div2);
+
+	/* Turn PLL off for configuration... */
+	snd_soc_update_bits(codec, WM8978_POWER_MANAGEMENT_1, 0x20, 0);
+
+	snd_soc_write(codec, WM8978_PLL_N, (pll_div.div2 << 4) | pll_div.n);
+	snd_soc_write(codec, WM8978_PLL_K1, pll_div.k >> 18);
+	snd_soc_write(codec, WM8978_PLL_K2, (pll_div.k >> 9) & 0x1ff);
+	snd_soc_write(codec, WM8978_PLL_K3, pll_div.k & 0x1ff);
+
+	/* ...and on again */
+	snd_soc_update_bits(codec, WM8978_POWER_MANAGEMENT_1, 0x20, 0x20);
+
+	if (f_opclk)
+		/* Output PLL (OPCLK) to GPIO1 */
+		snd_soc_update_bits(codec, WM8978_GPIO_CONTROL, 7, 4);
+
+	return 0;
+}
+
+/*
+ * Configure WM8978 clock dividers.
+ */
+static int wm8978_set_dai_clkdiv(struct snd_soc_dai *codec_dai,
+				 int div_id, int div)
+{
+	struct snd_soc_codec *codec = codec_dai->codec;
+	struct wm8978_priv *wm8978 = snd_soc_codec_get_drvdata(codec);
+	int ret = 0;
+
+	switch (div_id) {
+	case WM8978_OPCLKRATE:
+		wm8978->f_opclk = div;
+
+		if (wm8978->f_mclk)
+			/*
+			 * We know the MCLK frequency, the user has requested
+			 * OPCLK, configure the PLL based on that and start it
+			 * and OPCLK immediately. We will configure PLL to match
+			 * user-requested OPCLK frquency as good as possible.
+			 * In fact, it is likely, that matching the sampling
+			 * rate, when it becomes known, is more important, and
+			 * we will not be reconfiguring PLL then, because we
+			 * must not interrupt OPCLK. But it should be fine,
+			 * because typically the user will request OPCLK to run
+			 * at 256fs or 512fs, and for these cases we will also
+			 * find an exact MCLK divider configuration - it will
+			 * be equal to or double the OPCLK divisor.
+			 */
+			ret = wm8978_configure_pll(codec);
+		break;
+	case WM8978_BCLKDIV:
+		if (div & ~0x1c)
+			return -EINVAL;
+		snd_soc_update_bits(codec, WM8978_CLOCKING, 0x1c, div);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	dev_dbg(codec->dev, "%s: ID %d, value %u\n", __func__, div_id, div);
+
+	return ret;
+}
+
+/*
+ * @freq:	when .set_pll() us not used, freq is codec MCLK input frequency
+ */
+static int wm8978_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 wm8978_priv *wm8978 = snd_soc_codec_get_drvdata(codec);
+	int ret = 0;
+
+	dev_dbg(codec->dev, "%s: ID %d, freq %u\n", __func__, clk_id, freq);
+
+	if (freq) {
+		wm8978->f_mclk = freq;
+
+		/* Even if MCLK is used for system clock, might have to drive OPCLK */
+		if (wm8978->f_opclk)
+			ret = wm8978_configure_pll(codec);
+
+		/* Our sysclk is fixed to 256 * fs, will configure in .hw_params()  */
+
+		if (!ret)
+			wm8978->sysclk = clk_id;
+	}
+
+	if (wm8978->sysclk == WM8978_PLL && (!freq || clk_id == WM8978_MCLK)) {
+		/* Clock CODEC directly from MCLK */
+		snd_soc_update_bits(codec, WM8978_CLOCKING, 0x100, 0);
+
+		/* GPIO1 into default mode as input - before configuring PLL */
+		snd_soc_update_bits(codec, WM8978_GPIO_CONTROL, 7, 0);
+
+		/* Turn off PLL */
+		snd_soc_update_bits(codec, WM8978_POWER_MANAGEMENT_1, 0x20, 0);
+		wm8978->sysclk = WM8978_MCLK;
+		wm8978->f_pllout = 0;
+		wm8978->f_opclk = 0;
+	}
+
+	return ret;
+}
+
+/*
+ * Set ADC and Voice DAC format.
+ */
+static int wm8978_set_dai_fmt(struct snd_soc_dai *codec_dai, unsigned int fmt)
+{
+	struct snd_soc_codec *codec = codec_dai->codec;
+	/*
+	 * BCLK polarity mask = 0x100, LRC clock polarity mask = 0x80,
+	 * Data Format mask = 0x18: all will be calculated anew
+	 */
+	u16 iface = snd_soc_read(codec, WM8978_AUDIO_INTERFACE) & ~0x198;
+	u16 clk = snd_soc_read(codec, WM8978_CLOCKING);
+
+	dev_dbg(codec->dev, "%s\n", __func__);
+
+	/* set master/slave audio interface */
+	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
+	case SND_SOC_DAIFMT_CBM_CFM:
+		clk |= 1;
+		break;
+	case SND_SOC_DAIFMT_CBS_CFS:
+		clk &= ~1;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* interface format */
+	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
+	case SND_SOC_DAIFMT_I2S:
+		iface |= 0x10;
+		break;
+	case SND_SOC_DAIFMT_RIGHT_J:
+		break;
+	case SND_SOC_DAIFMT_LEFT_J:
+		iface |= 0x8;
+		break;
+	case SND_SOC_DAIFMT_DSP_A:
+		iface |= 0x18;
+		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 |= 0x180;
+		break;
+	case SND_SOC_DAIFMT_IB_NF:
+		iface |= 0x100;
+		break;
+	case SND_SOC_DAIFMT_NB_IF:
+		iface |= 0x80;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	snd_soc_write(codec, WM8978_AUDIO_INTERFACE, iface);
+	snd_soc_write(codec, WM8978_CLOCKING, clk);
+
+	return 0;
+}
+
+/*
+ * Set PCM DAI bit size and sample rate.
+ */
+static int wm8978_hw_params(struct snd_pcm_substream *substream,
+			    struct snd_pcm_hw_params *params,
+			    struct snd_soc_dai *dai)
+{
+	struct snd_soc_codec *codec = dai->codec;
+	struct wm8978_priv *wm8978 = snd_soc_codec_get_drvdata(codec);
+	/* Word length mask = 0x60 */
+	u16 iface_ctl = snd_soc_read(codec, WM8978_AUDIO_INTERFACE) & ~0x60;
+	/* Sampling rate mask = 0xe (for filters) */
+	u16 add_ctl = snd_soc_read(codec, WM8978_ADDITIONAL_CONTROL) & ~0xe;
+	u16 clking = snd_soc_read(codec, WM8978_CLOCKING);
+	enum wm8978_sysclk_src current_clk_id = clking & 0x100 ?
+		WM8978_PLL : WM8978_MCLK;
+	unsigned int f_sel, diff, diff_best = INT_MAX;
+	int i, best = 0;
+
+	if (!wm8978->f_mclk)
+		return -EINVAL;
+
+	/* bit size */
+	switch (params_width(params)) {
+	case 16:
+		break;
+	case 20:
+		iface_ctl |= 0x20;
+		break;
+	case 24:
+		iface_ctl |= 0x40;
+		break;
+	case 32:
+		iface_ctl |= 0x60;
+		break;
+	}
+
+	/* filter coefficient */
+	switch (params_rate(params)) {
+	case 8000:
+		add_ctl |= 0x5 << 1;
+		break;
+	case 11025:
+		add_ctl |= 0x4 << 1;
+		break;
+	case 16000:
+		add_ctl |= 0x3 << 1;
+		break;
+	case 22050:
+		add_ctl |= 0x2 << 1;
+		break;
+	case 32000:
+		add_ctl |= 0x1 << 1;
+		break;
+	case 44100:
+	case 48000:
+		break;
+	}
+
+	/* Sampling rate is known now, can configure the MCLK divider */
+	wm8978->f_256fs = params_rate(params) * 256;
+
+	if (wm8978->sysclk == WM8978_MCLK) {
+		wm8978->mclk_idx = -1;
+		f_sel = wm8978->f_mclk;
+	} else {
+		if (!wm8978->f_opclk) {
+			/* We only enter here, if OPCLK is not used */
+			int ret = wm8978_configure_pll(codec);
+			if (ret < 0)
+				return ret;
+		}
+		f_sel = wm8978->f_pllout;
+	}
+
+	if (wm8978->mclk_idx < 0) {
+		/* Either MCLK is used directly, or OPCLK is used */
+		if (f_sel < wm8978->f_256fs || f_sel > 12 * wm8978->f_256fs)
+			return -EINVAL;
+
+		for (i = 0; i < ARRAY_SIZE(mclk_numerator); i++) {
+			diff = abs(wm8978->f_256fs * 3 -
+				   f_sel * 3 * mclk_denominator[i] / mclk_numerator[i]);
+
+			if (diff < diff_best) {
+				diff_best = diff;
+				best = i;
+			}
+
+			if (!diff)
+				break;
+		}
+	} else {
+		/* OPCLK not used, codec driven by PLL */
+		best = wm8978->mclk_idx;
+		diff = 0;
+	}
+
+	if (diff)
+		dev_warn(codec->dev, "Imprecise sampling rate: %uHz%s\n",
+			f_sel * mclk_denominator[best] / mclk_numerator[best] / 256,
+			wm8978->sysclk == WM8978_MCLK ?
+			", consider using PLL" : "");
+
+	dev_dbg(codec->dev, "%s: width %d, rate %u, MCLK divisor #%d\n", __func__,
+		params_width(params), params_rate(params), best);
+
+	/* MCLK divisor mask = 0xe0 */
+	snd_soc_update_bits(codec, WM8978_CLOCKING, 0xe0, best << 5);
+
+	snd_soc_write(codec, WM8978_AUDIO_INTERFACE, iface_ctl);
+	snd_soc_write(codec, WM8978_ADDITIONAL_CONTROL, add_ctl);
+
+	if (wm8978->sysclk != current_clk_id) {
+		if (wm8978->sysclk == WM8978_PLL)
+			/* Run CODEC from PLL instead of MCLK */
+			snd_soc_update_bits(codec, WM8978_CLOCKING,
+					    0x100, 0x100);
+		else
+			/* Clock CODEC directly from MCLK */
+			snd_soc_update_bits(codec, WM8978_CLOCKING, 0x100, 0);
+	}
+
+	return 0;
+}
+
+static int wm8978_mute(struct snd_soc_dai *dai, int mute)
+{
+	struct snd_soc_codec *codec = dai->codec;
+
+	dev_dbg(codec->dev, "%s: %d\n", __func__, mute);
+
+	if (mute)
+		snd_soc_update_bits(codec, WM8978_DAC_CONTROL, 0x40, 0x40);
+	else
+		snd_soc_update_bits(codec, WM8978_DAC_CONTROL, 0x40, 0);
+
+	return 0;
+}
+
+static int wm8978_set_bias_level(struct snd_soc_codec *codec,
+				 enum snd_soc_bias_level level)
+{
+	u16 power1 = snd_soc_read(codec, WM8978_POWER_MANAGEMENT_1) & ~3;
+
+	switch (level) {
+	case SND_SOC_BIAS_ON:
+	case SND_SOC_BIAS_PREPARE:
+		power1 |= 1;  /* VMID 75k */
+		snd_soc_write(codec, WM8978_POWER_MANAGEMENT_1, power1);
+		break;
+	case SND_SOC_BIAS_STANDBY:
+		/* bit 3: enable bias, bit 2: enable I/O tie off buffer */
+		power1 |= 0xc;
+
+		if (codec->dapm.bias_level == SND_SOC_BIAS_OFF) {
+			/* Initial cap charge at VMID 5k */
+			snd_soc_write(codec, WM8978_POWER_MANAGEMENT_1,
+				      power1 | 0x3);
+			mdelay(100);
+		}
+
+		power1 |= 0x2;  /* VMID 500k */
+		snd_soc_write(codec, WM8978_POWER_MANAGEMENT_1, power1);
+		break;
+	case SND_SOC_BIAS_OFF:
+		/* Preserve PLL - OPCLK may be used by someone */
+		snd_soc_update_bits(codec, WM8978_POWER_MANAGEMENT_1, ~0x20, 0);
+		snd_soc_write(codec, WM8978_POWER_MANAGEMENT_2, 0);
+		snd_soc_write(codec, WM8978_POWER_MANAGEMENT_3, 0);
+		break;
+	}
+
+	dev_dbg(codec->dev, "%s: %d, %x\n", __func__, level, power1);
+
+	codec->dapm.bias_level = level;
+	return 0;
+}
+
+#define WM8978_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S20_3LE | \
+	SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S32_LE)
+
+static const struct snd_soc_dai_ops wm8978_dai_ops = {
+	.hw_params	= wm8978_hw_params,
+	.digital_mute	= wm8978_mute,
+	.set_fmt	= wm8978_set_dai_fmt,
+	.set_clkdiv	= wm8978_set_dai_clkdiv,
+	.set_sysclk	= wm8978_set_dai_sysclk,
+};
+
+/* Also supports 12kHz */
+static struct snd_soc_dai_driver wm8978_dai = {
+	.name = "wm8978-hifi",
+	.playback = {
+		.stream_name = "Playback",
+		.channels_min = 1,
+		.channels_max = 2,
+		.rates = SNDRV_PCM_RATE_8000_48000,
+		.formats = WM8978_FORMATS,
+	},
+	.capture = {
+		.stream_name = "Capture",
+		.channels_min = 1,
+		.channels_max = 2,
+		.rates = SNDRV_PCM_RATE_8000_48000,
+		.formats = WM8978_FORMATS,
+	},
+	.ops = &wm8978_dai_ops,
+	.symmetric_rates = 1,
+};
+
+static int wm8978_suspend(struct snd_soc_codec *codec)
+{
+	struct wm8978_priv *wm8978 = snd_soc_codec_get_drvdata(codec);
+
+	wm8978_set_bias_level(codec, SND_SOC_BIAS_OFF);
+	/* Also switch PLL off */
+	snd_soc_write(codec, WM8978_POWER_MANAGEMENT_1, 0);
+
+	regcache_mark_dirty(wm8978->regmap);
+
+	return 0;
+}
+
+static int wm8978_resume(struct snd_soc_codec *codec)
+{
+	struct wm8978_priv *wm8978 = snd_soc_codec_get_drvdata(codec);
+
+	/* Sync reg_cache with the hardware */
+	regcache_sync(wm8978->regmap);
+
+	wm8978_set_bias_level(codec, SND_SOC_BIAS_STANDBY);
+
+	if (wm8978->f_pllout)
+		/* Switch PLL on */
+		snd_soc_update_bits(codec, WM8978_POWER_MANAGEMENT_1, 0x20, 0x20);
+
+	return 0;
+}
+
+/*
+ * These registers contain an "update" bit - bit 8. This means, for example,
+ * that one can write new DAC digital volume for both channels, but only when
+ * the update bit is set, will also the volume be updated - simultaneously for
+ * both channels.
+ */
+static const int update_reg[] = {
+	WM8978_LEFT_DAC_DIGITAL_VOLUME,
+	WM8978_RIGHT_DAC_DIGITAL_VOLUME,
+	WM8978_LEFT_ADC_DIGITAL_VOLUME,
+	WM8978_RIGHT_ADC_DIGITAL_VOLUME,
+	WM8978_LEFT_INP_PGA_CONTROL,
+	WM8978_RIGHT_INP_PGA_CONTROL,
+	WM8978_LOUT1_HP_CONTROL,
+	WM8978_ROUT1_HP_CONTROL,
+	WM8978_LOUT2_SPK_CONTROL,
+	WM8978_ROUT2_SPK_CONTROL,
+};
+
+static int wm8978_probe(struct snd_soc_codec *codec)
+{
+	struct wm8978_priv *wm8978 = snd_soc_codec_get_drvdata(codec);
+	int i;
+
+	/*
+	 * Set default system clock to PLL, it is more precise, this is also the
+	 * default hardware setting
+	 */
+	wm8978->sysclk = WM8978_PLL;
+
+	/*
+	 * Set the update bit in all registers, that have one. This way all
+	 * writes to those registers will also cause the update bit to be
+	 * written.
+	 */
+	for (i = 0; i < ARRAY_SIZE(update_reg); i++)
+		snd_soc_update_bits(codec, update_reg[i], 0x100, 0x100);
+
+	return 0;
+}
+
+static struct snd_soc_codec_driver soc_codec_dev_wm8978 = {
+	.probe =	wm8978_probe,
+	.suspend =	wm8978_suspend,
+	.resume =	wm8978_resume,
+	.set_bias_level = wm8978_set_bias_level,
+
+	.controls = wm8978_snd_controls,
+	.num_controls = ARRAY_SIZE(wm8978_snd_controls),
+	.dapm_widgets = wm8978_dapm_widgets,
+	.num_dapm_widgets = ARRAY_SIZE(wm8978_dapm_widgets),
+	.dapm_routes = wm8978_dapm_routes,
+	.num_dapm_routes = ARRAY_SIZE(wm8978_dapm_routes),
+};
+
+static const struct regmap_config wm8978_regmap_config = {
+	.reg_bits = 7,
+	.val_bits = 9,
+
+	.max_register = WM8978_MAX_REGISTER,
+	.volatile_reg = wm8978_volatile,
+
+	.cache_type = REGCACHE_RBTREE,
+	.reg_defaults = wm8978_reg_defaults,
+	.num_reg_defaults = ARRAY_SIZE(wm8978_reg_defaults),
+};
+
+static int wm8978_i2c_probe(struct i2c_client *i2c,
+			    const struct i2c_device_id *id)
+{
+	struct wm8978_priv *wm8978;
+	int ret;
+
+	wm8978 = devm_kzalloc(&i2c->dev, sizeof(struct wm8978_priv),
+			      GFP_KERNEL);
+	if (wm8978 == NULL)
+		return -ENOMEM;
+
+	wm8978->regmap = devm_regmap_init_i2c(i2c, &wm8978_regmap_config);
+	if (IS_ERR(wm8978->regmap)) {
+		ret = PTR_ERR(wm8978->regmap);
+		dev_err(&i2c->dev, "Failed to allocate regmap: %d\n", ret);
+		return ret;
+	}
+
+	i2c_set_clientdata(i2c, wm8978);
+
+	/* Reset the codec */
+	ret = regmap_write(wm8978->regmap, WM8978_RESET, 0);
+	if (ret != 0) {
+		dev_err(&i2c->dev, "Failed to issue reset: %d\n", ret);
+		return ret;
+	}
+
+	ret = snd_soc_register_codec(&i2c->dev,
+			&soc_codec_dev_wm8978, &wm8978_dai, 1);
+	if (ret != 0) {
+		dev_err(&i2c->dev, "Failed to register CODEC: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int wm8978_i2c_remove(struct i2c_client *client)
+{
+	snd_soc_unregister_codec(&client->dev);
+
+	return 0;
+}
+
+static const struct i2c_device_id wm8978_i2c_id[] = {
+	{ "wm8978", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, wm8978_i2c_id);
+
+static struct i2c_driver wm8978_i2c_driver = {
+	.driver = {
+		.name = "wm8978",
+		.owner = THIS_MODULE,
+	},
+	.probe =    wm8978_i2c_probe,
+	.remove =   wm8978_i2c_remove,
+	.id_table = wm8978_i2c_id,
+};
+
+module_i2c_driver(wm8978_i2c_driver);
+
+MODULE_DESCRIPTION("ASoC WM8978 codec driver");
+MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de>");
+MODULE_LICENSE("GPL");