path: root/Documentation
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authorJean Delvare <khali@linux-fr.org>2010-10-28 20:31:50 +0200
committerJean Delvare <khali@endymion.delvare>2010-10-28 20:31:50 +0200
commitf6c61cff8bcb58b8dfb645d4243a049908c02024 (patch)
treebff2919dcf335f38cb36bdbd27fd5c5870e4b0e9 /Documentation
parentc36364dbf38382ef6be2fb99a3ce361a679c0ecb (diff)
hwmon: (lm85) Add support for ADT7468 high-frequency PWM mode
The ADT7468 supports a high-frequency PWM output mode where all PWM outputs are driven by a 22.5 kHz clock. Add support for this mode, and document it, as it may surprise the user that setting one PWM output frequency also affects the other PWM outputs. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Darrick J. Wong <djwong@us.ibm.com> Acked-by: Guenter Roeck <guenter.roeck@ericsson.com>
Diffstat (limited to 'Documentation')
1 files changed, 7 insertions, 0 deletions
diff --git a/Documentation/hwmon/lm85 b/Documentation/hwmon/lm85
index 83cd5bb1ac7..239258a63c8 100644
--- a/Documentation/hwmon/lm85
+++ b/Documentation/hwmon/lm85
@@ -101,6 +101,13 @@ Devices has confirmed this "bug". The ADT7463 is reported to work as
described in the documentation. The current lm85 driver does not show the
offset register.
+The ADT7468 has a high-frequency PWM mode, where all PWM outputs are
+driven by a 22.5 kHz clock. This is a global mode, not per-PWM output,
+which means that setting any PWM frequency above 11.3 kHz will switch
+all 3 PWM outputs to a 22.5 kHz frequency. Conversely, setting any PWM
+frequency below 11.3 kHz will switch all 3 PWM outputs to a frequency
+between 10 and 100 Hz, which can then be tuned separately.
See the vendor datasheets for more information. There is application note
from National (AN-1260) with some additional information about the LM85.
The Analog Devices datasheet is very detailed and describes a procedure for