xref: /OK3568_Linux_fs/kernel/Documentation/misc-devices/ics932s401.rst (revision 4882a59341e53eb6f0b4789bf948001014eff981)
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2*4882a593SmuzhiyunKernel driver ics932s401
3*4882a593Smuzhiyun========================
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5*4882a593SmuzhiyunSupported chips:
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun  * IDT ICS932S401
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9*4882a593Smuzhiyun    Prefix: 'ics932s401'
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun    Addresses scanned: I2C 0x69
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13*4882a593Smuzhiyun    Datasheet: Publicly available at the IDT website
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15*4882a593SmuzhiyunAuthor: Darrick J. Wong
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17*4882a593SmuzhiyunDescription
18*4882a593Smuzhiyun-----------
19*4882a593Smuzhiyun
20*4882a593SmuzhiyunThis driver implements support for the IDT ICS932S401 chip family.
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22*4882a593SmuzhiyunThis chip has 4 clock outputs--a base clock for the CPU (which is likely
23*4882a593Smuzhiyunmultiplied to get the real CPU clock), a system clock, a PCI clock, a USB
24*4882a593Smuzhiyunclock, and a reference clock.  The driver reports selected and actual
25*4882a593Smuzhiyunfrequency.  If spread spectrum mode is enabled, the driver also reports by what
26*4882a593Smuzhiyunpercent the clock signal is being spread, which should be between 0 and -0.5%.
27*4882a593SmuzhiyunAll frequencies are reported in KHz.
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29*4882a593SmuzhiyunThe ICS932S401 monitors all inputs continuously. The driver will not read
30*4882a593Smuzhiyunthe registers more often than once every other second.
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32*4882a593SmuzhiyunSpecial Features
33*4882a593Smuzhiyun----------------
34*4882a593Smuzhiyun
35*4882a593SmuzhiyunThe clocks could be reprogrammed to increase system speed.  I will not help you
36*4882a593Smuzhiyundo this, as you risk damaging your system!
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