ASoC: sgtl5000: Fix the cache handling

Since commit e5d80e8 (ASoC: sgtl5000: Convert to use regmap directly) a
kernel oops is observed after a suspend/resume sequence.

The kernel oops happens inside sgtl5000_restore_regs() as codec->reg_cache is no
longer a valid pointer.

Add the remaining register entries into sgtl5000_reg_defaults[] and remove
sgtl5000_restore_regs() completely, which allows suspend/resume to work fine and
make the code simpler.

Tested on a im53-qsb board.

Reported-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Tested-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

sound/soc/codecs/sgtl5000.c

@@ -36,25 +36,40 @@
 
 /* default value of sgtl5000 registers */
 static const struct reg_default sgtl5000_reg_defaults[] = {
+	{ SGTL5000_CHIP_DIG_POWER,		0x0000 },
 	{ SGTL5000_CHIP_CLK_CTRL,		0x0008 },
 	{ SGTL5000_CHIP_I2S_CTRL,		0x0010 },
 	{ SGTL5000_CHIP_SSS_CTRL,		0x0010 },
+	{ SGTL5000_CHIP_ADCDAC_CTRL,		0x020c },
 	{ SGTL5000_CHIP_DAC_VOL,		0x3c3c },
 	{ SGTL5000_CHIP_PAD_STRENGTH,		0x015f },
+	{ SGTL5000_CHIP_ANA_ADC_CTRL,		0x0000 },
 	{ SGTL5000_CHIP_ANA_HP_CTRL,		0x1818 },
 	{ SGTL5000_CHIP_ANA_CTRL,		0x0111 },
+	{ SGTL5000_CHIP_LINREG_CTRL,		0x0000 },
+	{ SGTL5000_CHIP_REF_CTRL,		0x0000 },
+	{ SGTL5000_CHIP_MIC_CTRL,		0x0000 },
+	{ SGTL5000_CHIP_LINE_OUT_CTRL,		0x0000 },
 	{ SGTL5000_CHIP_LINE_OUT_VOL,		0x0404 },
 	{ SGTL5000_CHIP_ANA_POWER,		0x7060 },
 	{ SGTL5000_CHIP_PLL_CTRL,		0x5000 },
+	{ SGTL5000_CHIP_CLK_TOP_CTRL,		0x0000 },
+	{ SGTL5000_CHIP_ANA_STATUS,		0x0000 },
+	{ SGTL5000_CHIP_SHORT_CTRL,		0x0000 },
+	{ SGTL5000_CHIP_ANA_TEST2,		0x0000 },
+	{ SGTL5000_DAP_CTRL,			0x0000 },
+	{ SGTL5000_DAP_PEQ,			0x0000 },
 	{ SGTL5000_DAP_BASS_ENHANCE,		0x0040 },
 	{ SGTL5000_DAP_BASS_ENHANCE_CTRL,	0x051f },
+	{ SGTL5000_DAP_AUDIO_EQ,		0x0000 },
 	{ SGTL5000_DAP_SURROUND,		0x0040 },
 	{ SGTL5000_DAP_EQ_BASS_BAND0,		0x002f },
 	{ SGTL5000_DAP_EQ_BASS_BAND1,		0x002f },
 	{ SGTL5000_DAP_EQ_BASS_BAND2,		0x002f },
 	{ SGTL5000_DAP_EQ_BASS_BAND3,		0x002f },
 	{ SGTL5000_DAP_EQ_BASS_BAND4,		0x002f },
 	{ SGTL5000_DAP_MAIN_CHAN,		0x8000 },
+	{ SGTL5000_DAP_MIX_CHAN,		0x0000 },
 	{ SGTL5000_DAP_AVC_CTRL,		0x0510 },
 	{ SGTL5000_DAP_AVC_THRESHOLD,		0x1473 },
 	{ SGTL5000_DAP_AVC_ATTACK,		0x0028 },
@@ -1068,71 +1083,11 @@ static int sgtl5000_suspend(struct snd_soc_codec *codec)
 	return 0;
 }
 
-/*
- * restore all sgtl5000 registers,
- * since a big hole between dap and regular registers,
- * we will restore them respectively.
- */
-static int sgtl5000_restore_regs(struct snd_soc_codec *codec)
-{
-	u16 *cache = codec->reg_cache;
-	u16 reg;
-
-	/* restore regular registers */
-	for (reg = 0; reg <= SGTL5000_CHIP_SHORT_CTRL; reg += 2) {
-
-		/* These regs should restore in particular order */
-		if (reg == SGTL5000_CHIP_ANA_POWER ||
-			reg == SGTL5000_CHIP_CLK_CTRL ||
-			reg == SGTL5000_CHIP_LINREG_CTRL ||
-			reg == SGTL5000_CHIP_LINE_OUT_CTRL ||
-			reg == SGTL5000_CHIP_REF_CTRL)
-			continue;
-
-		snd_soc_write(codec, reg, cache[reg]);
-	}
-
-	/* restore dap registers */
-	for (reg = SGTL5000_DAP_REG_OFFSET; reg < SGTL5000_MAX_REG_OFFSET; reg += 2)
-		snd_soc_write(codec, reg, cache[reg]);
-
-	/*
-	 * restore these regs according to the power setting sequence in
-	 * sgtl5000_set_power_regs() and clock setting sequence in
-	 * sgtl5000_set_clock().
-	 *
-	 * The order of restore is:
-	 * 1. SGTL5000_CHIP_CLK_CTRL MCLK_FREQ bits (1:0) should be restore after
-	 *    SGTL5000_CHIP_ANA_POWER PLL bits set
-	 * 2. SGTL5000_CHIP_LINREG_CTRL should be set before
-	 *    SGTL5000_CHIP_ANA_POWER LINREG_D restored
-	 * 3. SGTL5000_CHIP_REF_CTRL controls Analog Ground Voltage,
-	 *    prefer to resotre it after SGTL5000_CHIP_ANA_POWER restored
-	 */
-	snd_soc_write(codec, SGTL5000_CHIP_LINREG_CTRL,
-			cache[SGTL5000_CHIP_LINREG_CTRL]);
-
-	snd_soc_write(codec, SGTL5000_CHIP_ANA_POWER,
-			cache[SGTL5000_CHIP_ANA_POWER]);
-
-	snd_soc_write(codec, SGTL5000_CHIP_CLK_CTRL,
-			cache[SGTL5000_CHIP_CLK_CTRL]);
-
-	snd_soc_write(codec, SGTL5000_CHIP_REF_CTRL,
-			cache[SGTL5000_CHIP_REF_CTRL]);
-
-	snd_soc_write(codec, SGTL5000_CHIP_LINE_OUT_CTRL,
-			cache[SGTL5000_CHIP_LINE_OUT_CTRL]);
-	return 0;
-}
-
 static int sgtl5000_resume(struct snd_soc_codec *codec)
 {
 	/* Bring the codec back up to standby to enable regulators */
 	sgtl5000_set_bias_level(codec, SND_SOC_BIAS_STANDBY);
 
-	/* Restore registers by cached in memory */
-	sgtl5000_restore_regs(codec);
 	return 0;
 }
 #else