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ASoC: sta32x: add workaround for ESD reset issue

sta32x resets and loses all configuration during ESD test.
Work around by polling the CONFA register once a second
and restore all coeffcients and registers when CONFA
changes unexpectedly.

Signed-off-by: Johannes Stezenbach <js@sig21.net>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
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1 parent e012ba2 commit 3fb5eac50d66cab4a41177269432ffffcc3e67ac Johannes Stezenbach committed with broonie Nov 14, 2011
Showing with 50 additions and 1 deletion.
  1. +1 −0 include/sound/sta32x.h
  2. +49 −1 sound/soc/codecs/sta32x.c
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1 include/sound/sta32x.h
@@ -29,6 +29,7 @@ struct sta32x_platform_data {
int ch2_output_mapping;
int ch3_output_mapping;
int thermal_conf;
+ int needs_esd_watchdog;
};
#endif /* __LINUX_SND__STA32X_H */
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50 sound/soc/codecs/sta32x.c
@@ -27,6 +27,7 @@
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
+#include <linux/workqueue.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
@@ -80,6 +81,8 @@ struct sta32x_priv {
unsigned int format;
u32 coef_shadow[STA32X_COEF_COUNT];
+ struct delayed_work watchdog_work;
+ int shutdown;
};
static const DECLARE_TLV_DB_SCALE(mvol_tlv, -12700, 50, 1);
@@ -304,6 +307,46 @@ int sta32x_cache_sync(struct snd_soc_codec *codec)
return rc;
}
+/* work around ESD issue where sta32x resets and loses all configuration */
+static void sta32x_watchdog(struct work_struct *work)
+{
+ struct sta32x_priv *sta32x = container_of(work, struct sta32x_priv,
+ watchdog_work.work);
+ struct snd_soc_codec *codec = sta32x->codec;
+ unsigned int confa, confa_cached;
+
+ /* check if sta32x has reset itself */
+ confa_cached = snd_soc_read(codec, STA32X_CONFA);
+ codec->cache_bypass = 1;
+ confa = snd_soc_read(codec, STA32X_CONFA);
+ codec->cache_bypass = 0;
+ if (confa != confa_cached) {
+ codec->cache_sync = 1;
+ sta32x_cache_sync(codec);
+ }
+
+ if (!sta32x->shutdown)
+ schedule_delayed_work(&sta32x->watchdog_work,
+ round_jiffies_relative(HZ));
+}
+
+static void sta32x_watchdog_start(struct sta32x_priv *sta32x)
+{
+ if (sta32x->pdata->needs_esd_watchdog) {
+ sta32x->shutdown = 0;
+ schedule_delayed_work(&sta32x->watchdog_work,
+ round_jiffies_relative(HZ));
+ }
+}
+
+static void sta32x_watchdog_stop(struct sta32x_priv *sta32x)
+{
+ if (sta32x->pdata->needs_esd_watchdog) {
+ sta32x->shutdown = 1;
+ cancel_delayed_work_sync(&sta32x->watchdog_work);
+ }
+}
+
#define SINGLE_COEF(xname, index) \
{ .iface = SNDRV_CTL_ELEM_IFACE_MIXER, .name = xname, \
.info = sta32x_coefficient_info, \
@@ -714,6 +757,7 @@ static int sta32x_set_bias_level(struct snd_soc_codec *codec,
}
sta32x_cache_sync(codec);
+ sta32x_watchdog_start(sta32x);
}
/* Power up to mute */
@@ -730,7 +774,7 @@ static int sta32x_set_bias_level(struct snd_soc_codec *codec,
STA32X_CONFF_PWDN | STA32X_CONFF_EAPD,
STA32X_CONFF_PWDN);
msleep(300);
-
+ sta32x_watchdog_stop(sta32x);
regulator_bulk_disable(ARRAY_SIZE(sta32x->supplies),
sta32x->supplies);
break;
@@ -863,6 +907,9 @@ static int sta32x_probe(struct snd_soc_codec *codec)
sta32x->coef_shadow[60] = 0x400000;
sta32x->coef_shadow[61] = 0x400000;
+ if (sta32x->pdata->needs_esd_watchdog)
+ INIT_DELAYED_WORK(&sta32x->watchdog_work, sta32x_watchdog);
+
sta32x_set_bias_level(codec, SND_SOC_BIAS_STANDBY);
/* Bias level configuration will have done an extra enable */
regulator_bulk_disable(ARRAY_SIZE(sta32x->supplies), sta32x->supplies);
@@ -879,6 +926,7 @@ static int sta32x_remove(struct snd_soc_codec *codec)
{
struct sta32x_priv *sta32x = snd_soc_codec_get_drvdata(codec);
+ sta32x_watchdog_stop(sta32x);
sta32x_set_bias_level(codec, SND_SOC_BIAS_OFF);
regulator_bulk_disable(ARRAY_SIZE(sta32x->supplies), sta32x->supplies);
regulator_bulk_free(ARRAY_SIZE(sta32x->supplies), sta32x->supplies);

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