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42bc4b8b08
This (re-)configures the I2C arbitration lines as floating inputs when the AP powers off, and restores them strictly before the AP powers on. This is intended to prevent leakage when the AP is off and arbitration is not needed. This CL does not impact the AP on/suspend case. Signed-off-by: David Hendricks <dhendrix@chromium.org> BRANCH=snow BUG=chrome-os-partner:12573,chrome-os-partner:12381 TEST=manual (see notes below) - PA4: SPI1_NSS / AP_CLAIM, input w/ pull-up when AP on - PA6: SPI1_MISO / EC_CLAIM, output when AP is on - Both floating when AP off 8 = input with pull up/down, 4 = floating input, 1 = output AP off (before this CL): > rw 0x40010800 read 0x40010800 = 0x41484144 > gpioget SPI1_NSS 0* SPI1_NSS > gpioget SPI1_MISO 1 SPI1_MISO AP off (after this CL): > rw 0x40010800 read 0x40010800 = 0x44444144 > gpioget SPI1_NSS 0* SPI1_NSS > gpioget SPI1_MISO 0* SPI1_MISO AP on or suspended (before and after this CL): > rw 0x40010800 read 0x40010800 = 0x81484144 > gpioget SPI1_NSS 1* SPI1_NSS > gpioget SPI1_MISO 1* SPI1_MISO Additional testing: - "pmu 10000" and "cros_test i2c" in u-boot only showed the FET2 control changing (as expected). - "pmu 10000" and "while [ 1 ] ; do i2cdump -f -y -r 0-24 4 0x48 b ; done" and ran "suspend_stress_test" for a couple dozen iterations. The registers only changed as expected (FET1 and FET6 turned off when suspending). Change-Id: I72f5cb1883d01b1faad6c2db65dfa09d477e1885 Reviewed-on: https://gerrit.chromium.org/gerrit/32078 Commit-Ready: David Hendricks <dhendrix@chromium.org> Reviewed-by: David Hendricks <dhendrix@chromium.org> Tested-by: David Hendricks <dhendrix@chromium.org>