diff options
| author | Philip Chen <philipchen@google.com> | 2018-03-29 19:45:38 -0700 |
|---|---|---|
| committer | chrome-bot <chrome-bot@chromium.org> | 2018-03-31 01:56:30 -0700 |
| commit | 1a3851353892f7e26182e224a3a298e8f46dfa04 (patch) | |
| tree | d001800afe0db160df3b6a5bbd2c8c420476036d /driver | |
| parent | 375ecebcb74efcba906b12219ac73e37d3952799 (diff) | |
| download | chrome-ec-1a3851353892f7e26182e224a3a298e8f46dfa04.tar.gz | |
battery/max17055: Report BP_NOT_SURE before battery detection finishes
After a POR, max17055 takes ~2.5 seconds to finish the detection
for battery absence.
Let's report BP_NOT_SURE instead of the default BP_YES when the battery
detection result is not settled yet.
BUG=b:72697658
BRANCH=scarlet
TEST=boot scarlet w/o battery and confirm battery_is_present()
never return BP_YES before reporting BP_NO
Change-Id: Ia549b4b78a7403ce2c82802841b78bdd514c6200
Signed-off-by: Philip Chen <philipchen@google.com>
Reviewed-on: https://chromium-review.googlesource.com/989313
Commit-Ready: Philip Chen <philipchen@chromium.org>
Tested-by: Philip Chen <philipchen@chromium.org>
Reviewed-by: Philip Chen <philipchen@chromium.org>
Diffstat (limited to 'driver')
| -rw-r--r-- | driver/battery/max17055.c | 38 | ||||
| -rw-r--r-- | driver/battery/max17055.h | 2 |
2 files changed, 37 insertions, 3 deletions
diff --git a/driver/battery/max17055.c b/driver/battery/max17055.c index 05a6d7a5ae..99662284a6 100644 --- a/driver/battery/max17055.c +++ b/driver/battery/max17055.c @@ -18,6 +18,12 @@ #define CPRINTS(format, args...) cprints(CC_CHARGER, format, ## args) /* + * For max17055 to finish battery presence detection, this is the minimal time + * we have to wait since the last POR. LSB = 175ms. + */ +#define RELIABLE_BATT_DETECT_TIME 0x10 + +/* * Convert the register values to the units that match * smart battery protocol. */ @@ -219,12 +225,38 @@ int battery_status(int *status) enum battery_present battery_is_present(void) { - int status = 0; + int reg = 0; + static uint8_t batt_pres_sure; - if (max17055_read(REG_STATUS, &status)) + if (max17055_read(REG_STATUS, ®)) return BP_NOT_SURE; - if (status & STATUS_BST) + + if (reg & STATUS_BST) return BP_NO; + + if (!batt_pres_sure) { + /* + * The battery detection result is not reliable within + * ~2.8 secs since POR. + */ + if (!max17055_read(REG_TIMERH, ®)) { + /* + * The LSB of TIMERH reg is 3.2 hrs. If the reg has a + * nonzero value, battery detection must have been + * settled. + */ + if (reg) { + batt_pres_sure = 1; + return BP_YES; + } + if (!max17055_read(REG_TIMER, ®) && + ((uint32_t)reg > RELIABLE_BATT_DETECT_TIME)) { + batt_pres_sure = 1; + return BP_YES; + } + } + return BP_NOT_SURE; + } return BP_YES; } diff --git a/driver/battery/max17055.h b/driver/battery/max17055.h index be070e9896..5a3764d9de 100644 --- a/driver/battery/max17055.h +++ b/driver/battery/max17055.h @@ -37,12 +37,14 @@ #define REG_TEMPCO 0x39 #define REG_EMPTY_VOLTAGE 0x3a #define REG_FSTAT 0x3d +#define REG_TIMER 0x3e #define REG_QR_TABLE30 0x42 #define REG_DQACC 0x45 #define REG_DPACC 0x46 #define REG_STATUS2 0xb0 #define REG_HIBCFG 0xba #define REG_CONFIG2 0xbb +#define REG_TIMERH 0xbe #define REG_MODELCFG 0xdb /* Status reg (0x00) flags */ |