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authorDarrick J. Wong <djwong@us.ibm.com>2008-11-12 13:27:04 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2008-11-12 17:17:18 -0800
commita412ae3fb90ab49072b82c8cfa1e3e60d2b27005 (patch)
treea145d9346dc1a97eb21dc0c86bcaf62c7cd8c359 /Documentation
parentc0b4e3ab0c769913438aeb078535ff117eeba5fb (diff)
downloadlinux-a412ae3fb90ab49072b82c8cfa1e3e60d2b27005.tar.bz2
ics932s401: new clock generator chip driver
The ics932s401 is a clock generator chip. This driver allows users to read the current clock outputs. Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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+Kernel driver ics932s401
+======================
+
+Supported chips:
+ * IDT ICS932S401
+ Prefix: 'ics932s401'
+ Addresses scanned: I2C 0x69
+ Datasheet: Publically available at the IDT website
+
+Author: Darrick J. Wong
+
+Description
+-----------
+
+This driver implements support for the IDT ICS932S401 chip family.
+
+This chip has 4 clock outputs--a base clock for the CPU (which is likely
+multiplied to get the real CPU clock), a system clock, a PCI clock, a USB
+clock, and a reference clock. The driver reports selected and actual
+frequency. If spread spectrum mode is enabled, the driver also reports by what
+percent the clock signal is being spread, which should be between 0 and -0.5%.
+All frequencies are reported in KHz.
+
+The ICS932S401 monitors all inputs continuously. The driver will not read
+the registers more often than once every other second.
+
+Special Features
+----------------
+
+The clocks could be reprogrammed to increase system speed. I will not help you
+do this, as you risk damaging your system!