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mainboard/google/reef: Set IOSSTATE for trackpad I2C GPIOs

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I2C data (GPIO_132) and Clk (GPIO_133) lines are pulled low during
standby states S3/S0ix. This causes leakage of power. To reduce the
leakage, we have to pull these lines high during S3/S0ix. This is
done by programming the IOSSTATE to HIz. Also note that we are using
the internal pull ups to keep at SOC at 1.8V and the I2C lines are
not floating.

BUG=chrome-os-partner:62428,chrome-os-partner:61651
TEST=Enter S3/S0ix. Measure trackpad power. It should be less
than 4mW. Also I2c lines should be pulled high in S3/S0ix.

Change-Id: I5570ac37ec3cc41f6463dd6b858fdb56a20a1733
Signed-off-by: Vaibhav Shankar <vaibhav.shankar@intel.com>
Reviewed-on: https://review.coreboot.org/18251
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins)
This commit is contained in:
Vaibhav Shankar 2017-01-27 11:37:30 -08:00 • committed by Martin Roth
commit f224e836c0
1 changed files with 4 additions and 2 deletions
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6
src/mainboard/google/reef/variants/baseboard/gpio.c
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@ -101,8 +101,10 @@ static const struct pad_config gpio_table[] = {
PAD_CFG_NF(GPIO_131, UP_2K, DEEP, NF1), /* LPSS_I2C3_SCL */
/* I2C4 - trackpad */
PAD_CFG_NF(GPIO_132, UP_2K, DEEP, NF1), /* LPSS_I2C4_SDA */
PAD_CFG_NF(GPIO_133, UP_2K, DEEP, NF1), /* LPSS_I2C4_SCL */
/* LPSS_I2C4_SDA */
PAD_CFG_NF_IOSSTATE(GPIO_132, UP_2K, DEEP, NF1, HIZCRx1),
/* LPSS_I2C4_SCL */
PAD_CFG_NF_IOSSTATE(GPIO_133, UP_2K, DEEP, NF1, HIZCRx1),
/* I2C5 -- pen with external pulls */
PAD_CFG_NF(GPIO_134, NONE, DEEP, NF1), /* LPSS_I2C5_SDA */