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authorTimur Tabi <timur@freescale.com>2010-07-21 16:56:19 -0500
committerKumar Gala <galak@kernel.crashing.org>2010-10-07 09:49:47 -0500
commita2d12f88129a0a1a7c18630b7a48ade22a48416e (patch)
treeacda8b16207894aabd2627f05119500eeee88c8c /doc
parentb6bde930901b1375264865b979507eb25806cb77 (diff)
downloadu-boot-linaro-stable-a2d12f88129a0a1a7c18630b7a48ade22a48416e.tar.gz
p1022ds: add audclk hwconfig setting to enable codec reference clock
The Freescale P1022DS can use either a 12.288MHz or a 11.2896MHz reference clock for the audio codec, but by default both are disabled. Add a 'audclk' hwconfig option that allows the user to choose which clock he wants. The 12.288MHz clock allows the codec to use sampling rates of 16, 24, 32, 48, 64, and 96KHz. The 11.2896 clock allows 14700, 22050, 29400, 44100, 58800, and 88200Hz. Also configure a pin muxing to select some SSI signals, which will disable I2C1. Signed-off-by: Timur Tabi <timur@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
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diff --git a/doc/README.fsl-hwconfig b/doc/README.fsl-hwconfig
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+Freescale-specific 'hwconfig' options.
+
+This file documents Freescale-specific key:value pairs for the 'hwconfig'
+option. See README.hwconfig for general information about 'hwconfig'.
+
+audclk
+ Specific to the P1022DS reference board.
+
+ This option specifies which of the two oscillator frequencies should be
+ routed to the Wolfson WM8776 codec. The ngPIXIS can be programmed to
+ route either a 11.2896MHz or a 12.288MHz clock. The default is
+ 12.288MHz. This option has two effects. First, the MUX on the board
+ will be programmed accordingly. Second, the clock-frequency property
+ in the codec node in the device tree will be updated to the correct
+ value.
+
+ 'audclk:11'
+ Select the 11.2896MHz clock
+
+ 'audclk:12'
+ Select the 12.288MHz clock