[alsa-devel] [PATCH RFC 0/6] ASoC: sgtl5000: fix use of regulators and internal LDO

[Russell King - ARM Linux]

On Fri, Mar 06, 2015 at 03:49:39PM -0700, Eric Nelson wrote:
> Based on your review, it seems like the following is needed for a
> V2 patch (set):
> 
> - Move call to sgtl5000_fill_defaults() earlier in the
>   sgtl5000_i2c_probe routine, before adjusting ANA_POWER.
>   This will allow registers LINEREG_CTRL, CLK_CTRL, and even ANA_POWER
>   back into the default	register list.
> - Move regulators from codec to I2C device
> - switch to devm_regulator api
> - various code cleanups to simplify logic
> - Adjust regulator usage in SND_SOC_BIAS_OFF
> 
> I'll leave out the "write all default" registers for the moment.

I'll also interject here to say that, against mainline, I need this
patch to make the sgtl5k work on SolidRun's Hummingboard hardware.
Without this, the internal regulator seems to get powered down, and
we lose access to the device until the entire board is power cycled.

 sound/soc/codecs/sgtl5000.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/sound/soc/codecs/sgtl5000.c b/sound/soc/codecs/sgtl5000.c
index e182e6569bbd..79d5cbd65f36 100644
--- a/sound/soc/codecs/sgtl5000.c
+++ b/sound/soc/codecs/sgtl5000.c
@@ -825,6 +825,10 @@ static int ldo_regulator_disable(struct regulator_dev *dev)
 	struct snd_soc_codec *codec = (struct snd_soc_codec *)ldo->codec_data;
 
 	snd_soc_update_bits(codec, SGTL5000_CHIP_ANA_POWER,
+				SGTL5000_LINREG_SIMPLE_POWERUP,
+				SGTL5000_LINREG_SIMPLE_POWERUP);
+
+	snd_soc_update_bits(codec, SGTL5000_CHIP_ANA_POWER,
 				SGTL5000_LINEREG_D_POWERUP,
 				0);
 
@@ -1155,8 +1159,11 @@ static int sgtl5000_set_power_regs(struct snd_soc_codec *codec)
 		 * if vddio and vddd > 3.1v,
 		 * charge pump should be clean before set ana_pwr
 		 */
-		snd_soc_update_bits(codec, SGTL5000_CHIP_ANA_POWER,
-				SGTL5000_VDDC_CHRGPMP_POWERUP, 0);
+// FIXME: this is total crap - we have read this register above into
+// ana_pwr, which we then modify (above), and then write back to the
+// register below.  This modification just gets completely overwritten.
+//		snd_soc_update_bits(codec, SGTL5000_CHIP_ANA_POWER,
+//				SGTL5000_VDDC_CHRGPMP_POWERUP, 0);
 
 		/* VDDC use VDDIO rail */
 		lreg_ctrl |= SGTL5000_VDDC_ASSN_OVRD;


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