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From: Jarkko Nikula <jhnikula@gmail.com>
To: alsa-devel@alsa-project.org
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>,
	Peter Ujfalusi <peter.ujfalusi@nokia.com>,
	Liam Girdwood <lrg@slimlogic.co.uk>
Subject: [PATCH] ASoC: tpa6130a2: Revisit power-up sequence
Date: Mon,  8 Nov 2010 10:57:57 +0200	[thread overview]
Message-ID: <1289206677-11886-1-git-send-email-jhnikula@gmail.com> (raw)

There are no known problems with current power-up sequence which first sets
the /shutdown pin high and then enables the supply. However, swap the order
so that the device is kept in shutdown/reset mode during the supply voltage
transition since slowly rising voltages can usually cause problems if the
device is not kept in reset.

Signed-off-by: Jarkko Nikula <jhnikula@gmail.com>
Cc: Peter Ujfalusi <peter.ujfalusi@nokia.com>
---
 sound/soc/codecs/tpa6130a2.c |    7 +++----
 1 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/sound/soc/codecs/tpa6130a2.c b/sound/soc/codecs/tpa6130a2.c
index f9a92ea..9b98107 100644
--- a/sound/soc/codecs/tpa6130a2.c
+++ b/sound/soc/codecs/tpa6130a2.c
@@ -126,16 +126,15 @@ static int tpa6130a2_power(int power)
 
 	mutex_lock(&data->mutex);
 	if (power && !data->power_state) {
-		/* Power on */
-		if (data->power_gpio >= 0)
-			gpio_set_value(data->power_gpio, 1);
-
 		ret = regulator_enable(data->supply);
 		if (ret != 0) {
 			dev_err(&tpa6130a2_client->dev,
 				"Failed to enable supply: %d\n", ret);
 			goto exit;
 		}
+		/* Power on */
+		if (data->power_gpio >= 0)
+			gpio_set_value(data->power_gpio, 1);
 
 		data->power_state = 1;
 		ret = tpa6130a2_initialize();
-- 
1.7.2.3

             reply	other threads:[~2010-11-08  8:57 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-11-08  8:57 Jarkko Nikula [this message]
2010-11-08  9:38 ` [PATCH] ASoC: tpa6130a2: Revisit power-up sequence Peter Ujfalusi
2010-11-08 11:36 ` Mark Brown
2010-11-09 21:39 ` Liam Girdwood

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