ASoC: sgtl5000: fix cache handling

Cache handling in this driver is broken. The chip has 16-bit registers, yet the
register numbers also increase by 2 per register, i.e.  there are only
even-numbered registers. The cache in this driver, though, simply increments
register numbers, so it does need some mapping as seen in
sgtl5000_restore_regs(), note the '>> 1':

	snd_soc_write(codec, SGTL5000_CHIP_LINREG_CTRL,
                        cache[SGTL5000_CHIP_LINREG_CTRL >> 1]);

That, of course, won't work with snd_soc_update_bits(). (Thus, we won't even
notice the missing register 0x1c in the default regs which shifted all follwing
registers to wrong values.) Noticed on the MX28EVK where enabling the regulators
simply locked up the chip.

Refactor the routines and use a properly sized default_regs array which matches
the register layout of the underlying chip, i.e. create a truly flat cache.
This also saves some code which should make up for the bigger array a little.
When soc-core will somewhen have another cache type which handles a step size,
this conversion will also ease the transition.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Tested-by: Dong Aisheng <b29396@freescale.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Liam Girdwood <lrg@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@kernel.org

sound/soc/codecs/sgtl5000.c

@@ -33,73 +33,31 @@
 #define SGTL5000_DAP_REG_OFFSET	0x0100
 #define SGTL5000_MAX_REG_OFFSET	0x013A
 
-/* default value of sgtl5000 registers except DAP */
-static const u16 sgtl5000_regs[SGTL5000_MAX_REG_OFFSET >> 1] =  {
-	0xa011, /* 0x0000, CHIP_ID. 11 stand for revison 17 */
-	0x0000, /* 0x0002, CHIP_DIG_POWER. */
-	0x0008, /* 0x0004, CHIP_CKL_CTRL */
-	0x0010, /* 0x0006, CHIP_I2S_CTRL */
-	0x0000, /* 0x0008, reserved */
-	0x0008, /* 0x000A, CHIP_SSS_CTRL */
-	0x0000, /* 0x000C, reserved */
-	0x020c, /* 0x000E, CHIP_ADCDAC_CTRL */
-	0x3c3c, /* 0x0010, CHIP_DAC_VOL */
-	0x0000, /* 0x0012, reserved */
-	0x015f, /* 0x0014, CHIP_PAD_STRENGTH */
-	0x0000, /* 0x0016, reserved */
-	0x0000, /* 0x0018, reserved */
-	0x0000, /* 0x001A, reserved */
-	0x0000, /* 0x001E, reserved */
-	0x0000, /* 0x0020, CHIP_ANA_ADC_CTRL */
-	0x1818, /* 0x0022, CHIP_ANA_HP_CTRL */
-	0x0111, /* 0x0024, CHIP_ANN_CTRL */
-	0x0000, /* 0x0026, CHIP_LINREG_CTRL */
-	0x0000, /* 0x0028, CHIP_REF_CTRL */
-	0x0000, /* 0x002A, CHIP_MIC_CTRL */
-	0x0000, /* 0x002C, CHIP_LINE_OUT_CTRL */
-	0x0404, /* 0x002E, CHIP_LINE_OUT_VOL */
-	0x7060, /* 0x0030, CHIP_ANA_POWER */
-	0x5000, /* 0x0032, CHIP_PLL_CTRL */
-	0x0000, /* 0x0034, CHIP_CLK_TOP_CTRL */
-	0x0000, /* 0x0036, CHIP_ANA_STATUS */
-	0x0000, /* 0x0038, reserved */
-	0x0000, /* 0x003A, CHIP_ANA_TEST2 */
-	0x0000, /* 0x003C, CHIP_SHORT_CTRL */
-	0x0000, /* reserved */
-};
-
-/* default value of dap registers */
-static const u16 sgtl5000_dap_regs[] = {
-	0x0000, /* 0x0100, DAP_CONTROL */
-	0x0000, /* 0x0102, DAP_PEQ */
-	0x0040, /* 0x0104, DAP_BASS_ENHANCE */
-	0x051f, /* 0x0106, DAP_BASS_ENHANCE_CTRL */
-	0x0000, /* 0x0108, DAP_AUDIO_EQ */
-	0x0040, /* 0x010A, DAP_SGTL_SURROUND */
-	0x0000, /* 0x010C, DAP_FILTER_COEF_ACCESS */
-	0x0000, /* 0x010E, DAP_COEF_WR_B0_MSB */
-	0x0000, /* 0x0110, DAP_COEF_WR_B0_LSB */
-	0x0000, /* 0x0112, reserved */
-	0x0000, /* 0x0114, reserved */
-	0x002f, /* 0x0116, DAP_AUDIO_EQ_BASS_BAND0 */
-	0x002f, /* 0x0118, DAP_AUDIO_EQ_BAND0 */
-	0x002f, /* 0x011A, DAP_AUDIO_EQ_BAND2 */
-	0x002f, /* 0x011C, DAP_AUDIO_EQ_BAND3 */
-	0x002f, /* 0x011E, DAP_AUDIO_EQ_TREBLE_BAND4 */
-	0x8000, /* 0x0120, DAP_MAIN_CHAN */
-	0x0000, /* 0x0122, DAP_MIX_CHAN */
-	0x0510, /* 0x0124, DAP_AVC_CTRL */
-	0x1473, /* 0x0126, DAP_AVC_THRESHOLD */
-	0x0028, /* 0x0128, DAP_AVC_ATTACK */
-	0x0050, /* 0x012A, DAP_AVC_DECAY */
-	0x0000, /* 0x012C, DAP_COEF_WR_B1_MSB */
-	0x0000, /* 0x012E, DAP_COEF_WR_B1_LSB */
-	0x0000, /* 0x0130, DAP_COEF_WR_B2_MSB */
-	0x0000, /* 0x0132, DAP_COEF_WR_B2_LSB */
-	0x0000, /* 0x0134, DAP_COEF_WR_A1_MSB */
-	0x0000, /* 0x0136, DAP_COEF_WR_A1_LSB */
-	0x0000, /* 0x0138, DAP_COEF_WR_A2_MSB */
-	0x0000, /* 0x013A, DAP_COEF_WR_A2_LSB */
+/* default value of sgtl5000 registers */
+static const u16 sgtl5000_regs[SGTL5000_MAX_REG_OFFSET] =  {
+	[SGTL5000_CHIP_CLK_CTRL] = 0x0008,
+	[SGTL5000_CHIP_I2S_CTRL] = 0x0010,
+	[SGTL5000_CHIP_SSS_CTRL] = 0x0008,
+	[SGTL5000_CHIP_DAC_VOL] = 0x3c3c,
+	[SGTL5000_CHIP_PAD_STRENGTH] = 0x015f,
+	[SGTL5000_CHIP_ANA_HP_CTRL] = 0x1818,
+	[SGTL5000_CHIP_ANA_CTRL] = 0x0111,
+	[SGTL5000_CHIP_LINE_OUT_VOL] = 0x0404,
+	[SGTL5000_CHIP_ANA_POWER] = 0x7060,
+	[SGTL5000_CHIP_PLL_CTRL] = 0x5000,
+	[SGTL5000_DAP_BASS_ENHANCE] = 0x0040,
+	[SGTL5000_DAP_BASS_ENHANCE_CTRL] = 0x051f,
+	[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_AVC_CTRL] = 0x0510,
+	[SGTL5000_DAP_AVC_THRESHOLD] = 0x1473,
+	[SGTL5000_DAP_AVC_ATTACK] = 0x0028,
+	[SGTL5000_DAP_AVC_DECAY] = 0x0050,
 };
 
 /* regulator supplies for sgtl5000, VDDD is an optional external supply */
@@ -1023,12 +981,10 @@ static int sgtl5000_suspend(struct snd_soc_codec *codec, pm_message_t state)
 static int sgtl5000_restore_regs(struct snd_soc_codec *codec)
 {
 	u16 *cache = codec->reg_cache;
-	int i;
-	int regular_regs = SGTL5000_CHIP_SHORT_CTRL >> 1;
+	u16 reg;
 
 	/* restore regular registers */
-	for (i = 0; i < regular_regs; i++) {
-		int reg = i << 1;
+	for (reg = 0; reg <= SGTL5000_CHIP_SHORT_CTRL; reg += 2) {
 
 		/* this regs depends on the others */
 		if (reg == SGTL5000_CHIP_ANA_POWER ||
@@ -1038,35 +994,31 @@ static int sgtl5000_restore_regs(struct snd_soc_codec *codec)
 			reg == SGTL5000_CHIP_CLK_CTRL)
 			continue;
 
-		snd_soc_write(codec, reg, cache[i]);
+		snd_soc_write(codec, reg, cache[reg]);
 	}
 
 	/* restore dap registers */
-	for (i = SGTL5000_DAP_REG_OFFSET >> 1;
-			i < SGTL5000_MAX_REG_OFFSET >> 1; i++) {
-		int reg = i << 1;
-
-		snd_soc_write(codec, reg, cache[i]);
-	}
+	for (reg = SGTL5000_DAP_REG_OFFSET; reg < SGTL5000_MAX_REG_OFFSET; reg += 2)
+		snd_soc_write(codec, reg, cache[reg]);
 
 	/*
 	 * restore power and other regs according
 	 * to set_power() and set_clock()
 	 */
 	snd_soc_write(codec, SGTL5000_CHIP_LINREG_CTRL,
-			cache[SGTL5000_CHIP_LINREG_CTRL >> 1]);
+			cache[SGTL5000_CHIP_LINREG_CTRL]);
 
 	snd_soc_write(codec, SGTL5000_CHIP_ANA_POWER,
-			cache[SGTL5000_CHIP_ANA_POWER >> 1]);
+			cache[SGTL5000_CHIP_ANA_POWER]);
 
 	snd_soc_write(codec, SGTL5000_CHIP_CLK_CTRL,
-			cache[SGTL5000_CHIP_CLK_CTRL >> 1]);
+			cache[SGTL5000_CHIP_CLK_CTRL]);
 
 	snd_soc_write(codec, SGTL5000_CHIP_REF_CTRL,
-			cache[SGTL5000_CHIP_REF_CTRL >> 1]);
+			cache[SGTL5000_CHIP_REF_CTRL]);
 
 	snd_soc_write(codec, SGTL5000_CHIP_LINE_OUT_CTRL,
-			cache[SGTL5000_CHIP_LINE_OUT_CTRL >> 1]);
+			cache[SGTL5000_CHIP_LINE_OUT_CTRL]);
 	return 0;
 }
 
@@ -1454,16 +1406,6 @@ static __devinit int sgtl5000_i2c_probe(struct i2c_client *client,
 	if (!sgtl5000)
 		return -ENOMEM;
 
-	/*
-	 * copy DAP default values to default value array.
-	 * sgtl5000 register space has a big hole, merge it
-	 * at init phase makes life easy.
-	 * FIXME: should we drop 'const' of sgtl5000_regs?
-	 */
-	memcpy((void *)(&sgtl5000_regs[0] + (SGTL5000_DAP_REG_OFFSET >> 1)),
-			sgtl5000_dap_regs,
-			SGTL5000_MAX_REG_OFFSET - SGTL5000_DAP_REG_OFFSET);
-
 	i2c_set_clientdata(client, sgtl5000);
 
 	ret = snd_soc_register_codec(&client->dev,