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author | Sebastian Leonhardt <sebastian.leonhardt@web.de> | 2015-09-10 23:57:25 +0200 |
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committer | Gerrit Rockbox <gerrit@rockbox.org> | 2015-09-24 23:06:18 +0200 |
commit | 399904a916f3b17d2d6ee5817d5f1a53ffe62d30 (patch) | |
tree | 4a633aed295148f68bf665c281cba8f219e8f0c5 | |
parent | 1cada1f8339d6b5f8506277f80e62aaef77ab774 (diff) | |
download | rockbox-399904a916f3b17d2d6ee5817d5f1a53ffe62d30.tar.gz rockbox-399904a916f3b17d2d6ee5817d5f1a53ffe62d30.zip |
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 67ce9e3ed9..3a014f7527 100644 --- a/firmware/drivers/audio/ak4537.c +++ b/firmware/drivers/audio/ak4537.c | |||
@@ -176,6 +176,12 @@ void audiohw_close(void) | |||
176 | /* power down the DAC */ | 176 | /* power down the DAC */ |
177 | akc_clear(AK4537_PM2, PMDAC); | 177 | akc_clear(AK4537_PM2, PMDAC); |
178 | 178 | ||
179 | /* Let the common voltage fall down before powering down headphone amp, | ||
180 | or a pop noise will occur. The fall time depends on the capacitor value | ||
181 | connected with the MUTET pin and is 100k*C up to 250k*C. | ||
182 | For Samsung YH devices (4.7uF) a minimum time of 470ms is needed. */ | ||
183 | udelay(800000); | ||
184 | |||
179 | /* power down the headphone amp */ | 185 | /* power down the headphone amp */ |
180 | akc_set(AK4537_SIGSEL2, HPL | HPR); | 186 | akc_set(AK4537_SIGSEL2, HPL | HPR); |
181 | 187 | ||
@@ -187,7 +193,6 @@ void audiohw_close(void) | |||
187 | 193 | ||
188 | /* power down VCOM */ | 194 | /* power down VCOM */ |
189 | akc_clear(AK4537_PM1, PMVCM); | 195 | akc_clear(AK4537_PM1, PMVCM); |
190 | udelay(100000); | ||
191 | 196 | ||
192 | akcodec_close(); /* target-specific */ | 197 | akcodec_close(); /* target-specific */ |
193 | } | 198 | } |