diff options
| author | Vic Yang <victoryang@chromium.org> | 2013-05-20 17:31:17 +0800 |
|---|---|---|
| committer | ChromeBot <chrome-bot@google.com> | 2013-05-20 10:11:04 -0700 |
| commit | 2d1268d891b525e71e3b268d0f90aa89137c008d (patch) | |
| tree | 5d6292ce072e368cacbe5c419ba14143928e627e | |
| parent | 70ada0603c88d0fc2e074768f99abc6e3fcf0fe1 (diff) | |
| download | chrome-ec-2d1268d891b525e71e3b268d0f90aa89137c008d.tar.gz | |
Draw more current when lower than 500mA
If the current value is lower than 500mA and voltage is higher than
4.55V, draw more current.
Also to make PWM duty cycle more stable, disable fast mode once we hit
low voltage condition.
BUG=chrome-os-partner:19486
TEST=Plug in a low voltage USB host. Check we draw more current.
BRANCH=spring
Change-Id: I91ee97ca15247d49427d4db34d17a0d0c55b2684
Signed-off-by: Vic Yang <victoryang@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/55722
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
| -rw-r--r-- | common/extpower_usb.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/common/extpower_usb.c b/common/extpower_usb.c index 3628c9541c..719527f4a3 100644 --- a/common/extpower_usb.c +++ b/common/extpower_usb.c @@ -69,6 +69,7 @@ enum ilim_config { #define PWM_CTRL_VBUS_HARD_LOW 4400 #define PWM_CTRL_VBUS_LOW 4500 #define PWM_CTRL_VBUS_HIGH 4700 /* Must be higher than 4.5V */ +#define PWM_CTRL_VBUS_HIGH_500MA 4550 /* Delay for signals to settle */ #define DELAY_POWER_MS 20 @@ -90,6 +91,7 @@ static int current_dev_type = TSU6721_TYPE_NONE; static int nominal_pwm_duty; static int current_pwm_duty; static int user_pwm_duty = -1; +static int pwm_fast_mode; static int pending_tsu6721_reset; @@ -315,7 +317,8 @@ static int pwm_get_next_lower(void) int fast_next = current_pwm_duty - PWM_CTRL_STEP_FAST_DOWN; if (current_limit_mode == LIMIT_AGGRESSIVE) { - if (fast_next >= nominal_pwm_duty - PWM_CTRL_OC_MARGIN && + if (pwm_fast_mode && + fast_next >= nominal_pwm_duty - PWM_CTRL_OC_MARGIN && fast_next >= over_current_pwm_duty) return MAX(fast_next, 0); if (current_pwm_duty > nominal_pwm_duty - @@ -340,6 +343,15 @@ static int pwm_check_vbus_low(int vbus, int battery_current) return vbus < PWM_CTRL_VBUS_HARD_LOW && current_pwm_duty < 100; } +static int pwm_check_vbus_high(int vbus) +{ + if (vbus > PWM_CTRL_VBUS_HIGH) + return 1; + if (vbus > PWM_CTRL_VBUS_HIGH_500MA && current_pwm_duty > I_LIMIT_500MA) + return 1; + return 0; +} + static void pwm_nominal_duty_cycle(int percent) { int dummy; @@ -351,6 +363,7 @@ static void pwm_nominal_duty_cycle(int percent) else set_pwm_duty_cycle(percent + PWM_CTRL_BEGIN_OFFSET); nominal_pwm_duty = percent; + pwm_fast_mode = 1; } static void adc_watch_toad(void) @@ -667,8 +680,9 @@ static void pwm_tweak(void) */ if (pwm_check_vbus_low(vbus, current)) { set_pwm_duty_cycle(current_pwm_duty + PWM_CTRL_STEP_UP); + pwm_fast_mode = 0; CPRINTF("[%T PWM duty up %d%%]\n", current_pwm_duty); - } else if (vbus > PWM_CTRL_VBUS_HIGH) { + } else if (pwm_check_vbus_high(vbus)) { next = pwm_get_next_lower(); if (next >= 0) { set_pwm_duty_cycle(next); |