From af8ee11209e749c75eabf32b2a4ca631f396acf8 Mon Sep 17 00:00:00 2001 From: Fabio Estevam Date: Thu, 9 May 2013 21:15:47 -0300 Subject: [PATCH] ASoC: sgtl5000: Fix driver probe after reset After a 'reboot' command in Linux or after pressing the system's reset button the sgtl5000 driver fails to probe: sgtl5000 0-000a: Device with ID register ffff is not a sgtl5000 sgtl5000 0-000a: ASoC: failed to probe CODEC -19 imx-sgtl5000 sound.12: ASoC: failed to instantiate card -19 imx-sgtl5000 sound.12: snd_soc_register_card failed (-19) sgtl5000 codec does not have a reset line, nor a reset command in software, so after a system reset the codec does not contain the default register values from sgtl5000_reg_defaults[] anymore, as these are only valid after a power-on-reset cycle. Fix this issue by explicitly reading all the reset register values from sgtl5000_reg_defaults[] and writing them back into sgtl5000 to ensure a sane state. Signed-off-by: Fabio Estevam Tested-by: Eric Nelson Signed-off-by: Mark Brown --- sound/soc/codecs/sgtl5000.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/sound/soc/codecs/sgtl5000.c b/sound/soc/codecs/sgtl5000.c index 1ab356ab0f31..1c3b20fc7ec3 100644 --- a/sound/soc/codecs/sgtl5000.c +++ b/sound/soc/codecs/sgtl5000.c @@ -1468,6 +1468,31 @@ static const struct regmap_config sgtl5000_regmap = { .num_reg_defaults = ARRAY_SIZE(sgtl5000_reg_defaults), }; +/* + * Write all the default values from sgtl5000_reg_defaults[] array into the + * sgtl5000 registers, to make sure we always start with the sane registers + * values as stated in the datasheet. + * + * Since sgtl5000 does not have a reset line, nor a reset command in software, + * we follow this approach to guarantee we always start from the default values + * and avoid problems like, not being able to probe after an audio playback + * followed by a system reset or a 'reboot' command in Linux + */ +static int sgtl5000_fill_defaults(struct sgtl5000_priv *sgtl5000) +{ + int i, ret, val, index; + + for (i = 0; i < ARRAY_SIZE(sgtl5000_reg_defaults); i++) { + val = sgtl5000_reg_defaults[i].def; + index = sgtl5000_reg_defaults[i].reg; + ret = regmap_write(sgtl5000->regmap, index, val); + if (ret) + return ret; + } + + return 0; +} + static int sgtl5000_i2c_probe(struct i2c_client *client, const struct i2c_device_id *id) { @@ -1503,6 +1528,11 @@ static int sgtl5000_i2c_probe(struct i2c_client *client, i2c_set_clientdata(client, sgtl5000); + /* Ensure sgtl5000 will start with sane register values */ + ret = sgtl5000_fill_defaults(sgtl5000); + if (ret) + return ret; + ret = snd_soc_register_codec(&client->dev, &sgtl5000_driver, &sgtl5000_dai, 1); return ret; -- 2.11.0