diff options
| author | Naresh G Solanki <naresh.solanki@intel.com> | 2017-06-19 15:07:44 +0530 |
|---|---|---|
| committer | Furquan Shaikh <furquan@google.com> | 2017-07-12 05:52:33 +0000 |
| commit | 3d384486190c37e8162543fed53da0a7040712d9 (patch) | |
| tree | f60b497d4497ded76192a74bc08c07f0f1da856a /src/mainboard | |
| parent | 3214bc4ecca20bb44aa9a94f164c7fb4feb76c0b (diff) | |
mb/google/soraka: Do not reset PMIC during sleep
1. Due to reset signal, PMIC loses its internal register state. This
causes PMIC to be in improper state after sleep.
2. The intent of reset signal is to reset internal state of PMIC (which
happens once during power on), hence avoid asserting reset signal
when not needed.
3. As per PMIC (TPS68470) datasheet, device can be kept in SLEEP mode
when not in use to save max possible power.
To fix the same, do not reset PMIC while entering sleep.
By keeping PMIC in SLEEP mode, Power consumption is < 1uW (Typ) upto
3.63uW (Max). Refs: TPS68470 datasheet.
Measured value: 0.66uW
TEST= Build the firmware for Soraka & boot to OS. Do S3 resume & check
whether PMIC internal registers state are preserved.
Change-Id: I93ce4d76b0376b64ae6d1067aca0fd7467af3582
Signed-off-by: Naresh G Solanki <naresh.solanki@intel.com>
Reviewed-on: https://review.coreboot.org/20264
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Diffstat (limited to 'src/mainboard')
| -rw-r--r-- | src/mainboard/google/poppy/smihandler.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/src/mainboard/google/poppy/smihandler.c b/src/mainboard/google/poppy/smihandler.c index 30b009dd6f..1a86d0f773 100644 --- a/src/mainboard/google/poppy/smihandler.c +++ b/src/mainboard/google/poppy/smihandler.c @@ -29,8 +29,7 @@ void mainboard_smi_espi_handler(void) static void mainboard_gpio_smi_sleep(void) { - /* Hold camera device in reset and then power it down. */ - gpio_set(EN_CAM_PMIC_RST_L, 0); + /* Power down camera PMIC */ gpio_set(EN_PP3300_DX_CAM, 0); } |