[Sorry for the top-post] I think this makes sense. Please submit a formal patch, thanks. ________________________________________ From: Clemens Gruber <clemens.gruber@xxxxxxxxxxxx> Sent: Tuesday, May 31, 2016 1:58:03 PM To: alsa-devel@xxxxxxxxxxxxxxxx Cc: Mark Brown; Fabio Estevam Subject: [RFC] sgtl5000: check VDDD-supply instead of revision Hi, I am using a SGTL5000 rev 0x11 with external VDDD, as recommended by NXP documentation and errata sheet: http://cache.nxp.com/files/analog/doc/errata/SGTL5000ER.pdf The linux sgtl5000 codec driver contains a comment, warning that external VDDD can't be used on revisions >= 0x11, which is probably a leftover from the first implementation. This is very confusing because it contradicts the NXP documentation. Also, on every boot, the user gets a warning that the SGTL5000 is using the internal LDO (even though external VDDD is present). Maybe instead of checking the revision, we should only check if the VDDD-supply regulator exists and only if it does not exist, call sgtl5000_replace_vddd_with_ldo? I'd like to hear your comments if this approach is valid or if I missed something in my assumptions. In my DT, the VDDD-supply regulator is just a dummy / regulator-fixed with regulator-always-on; set, because the 1.8V external VDDD supply on my board is always powered on. I could not test if it works with regulator-fixed with gpio nodes, which actually switch the supply line on or off. If everything is OK, I'd send a formal patch to the mailing list. See below for the current state of my patch. Tested on an i.MX6Q board with SGTL5000 rev 0x11 and external VDDD. Thanks, Clemens --- sound/soc/codecs/sgtl5000.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-) diff --git a/sound/soc/codecs/sgtl5000.c b/sound/soc/codecs/sgtl5000.c index 08b4046..fbad4fb 100644 --- a/sound/soc/codecs/sgtl5000.c +++ b/sound/soc/codecs/sgtl5000.c @@ -1286,17 +1286,14 @@ static int sgtl5000_enable_regulators(struct snd_soc_codec *codec) for (i = 0; i < ARRAY_SIZE(sgtl5000->supplies); i++) sgtl5000->supplies[i].supply = supply_names[i]; - /* External VDDD only works before revision 0x11 */ - if (sgtl5000->revision < 0x11) { - vddd = regulator_get_optional(codec->dev, "VDDD"); - if (IS_ERR(vddd)) { - /* See if it's just not registered yet */ - if (PTR_ERR(vddd) == -EPROBE_DEFER) - return -EPROBE_DEFER; - } else { - external_vddd = 1; - regulator_put(vddd); - } + vddd = regulator_get_optional(codec->dev, "VDDD"); + if (IS_ERR(vddd)) { + /* See if it's just not registered yet */ + if (PTR_ERR(vddd) == -EPROBE_DEFER) + return -EPROBE_DEFER; + } else { + external_vddd = 1; + regulator_put(vddd); } if (!external_vddd) { -- 2.8.3 _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
