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| author | Sebastian Leonhardt <sebastian.leonhardt@web.de> | 2015-09-10 23:57:25 +0200 |
|---|---|---|
| committer | Gerrit Rockbox <gerrit@rockbox.org> | 2015-09-24 23:06:18 +0200 |
| commit | 399904a916f3b17d2d6ee5817d5f1a53ffe62d30 (patch) | |
| tree | 4a633aed295148f68bf665c281cba8f219e8f0c5 | |
| parent | 1cada1f8339d6b5f8506277f80e62aaef77ab774 (diff) | |
| download | rockbox-399904a916f3b17d2d6ee5817d5f1a53ffe62d30.zip rockbox-399904a916f3b17d2d6ee5817d5f1a53ffe62d30.tar.gz rockbox-399904a916f3b17d2d6ee5817d5f1a53ffe62d30.tar.bz2 rockbox-399904a916f3b17d2d6ee5817d5f1a53ffe62d30.tar.xz | |
Samsung YHxxx: reduce pop noise on power down
Change-Id: Ifc82ac1051ed05527393838d8aa93bde65287b5d
| -rw-r--r-- | firmware/drivers/audio/ak4537.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/firmware/drivers/audio/ak4537.c b/firmware/drivers/audio/ak4537.c index 67ce9e3..3a014f7 100644 --- a/firmware/drivers/audio/ak4537.c +++ b/firmware/drivers/audio/ak4537.c @@ -176,6 +176,12 @@ void audiohw_close(void) /* power down the DAC */ akc_clear(AK4537_PM2, PMDAC); + /* Let the common voltage fall down before powering down headphone amp, + or a pop noise will occur. The fall time depends on the capacitor value + connected with the MUTET pin and is 100k*C up to 250k*C. + For Samsung YH devices (4.7uF) a minimum time of 470ms is needed. */ + udelay(800000); + /* power down the headphone amp */ akc_set(AK4537_SIGSEL2, HPL | HPR); @@ -187,7 +193,6 @@ void audiohw_close(void) /* power down VCOM */ akc_clear(AK4537_PM1, PMVCM); - udelay(100000); akcodec_close(); /* target-specific */ } |