diff options
author | Wai-Hong Tam <waihong@google.com> | 2018-09-19 15:10:57 -0700 |
---|---|---|
committer | chrome-bot <chrome-bot@chromium.org> | 2018-10-30 01:04:51 -0700 |
commit | b47ed2a108c679de26be89fa258931ddf040e446 (patch) | |
tree | a170884ea21d2a7c21f0a72ed06d299a11ed857b /power | |
parent | 5f068e277ba6de108615aa3190ccb14b316b67f0 (diff) | |
download | chrome-ec-b47ed2a108c679de26be89fa258931ddf040e446.tar.gz |
cheza: Monitor the WARM_RESET_L signal to hold AP
This change is a backup solution if JTAG_SRST gets fused out.
The WARM_RESET_L signal is wired to JTAG_SRST, such that we can
hold AP when servo/H1 programs the AP SPI flash. But when JTAG_SRST
gets fused out (just in case it happens), still have a way to hold
AP, i.e. overdriving the AP_RST_L and PS_HOLD signals.
The WARM_RESET_L signal is pulled by a rail from PMIC, the same as
POWER_GOOD. The drop of WARM_RESET_L may be caused by either servo/
cr50 holds the signal or its pull-up rail drops. We should handle
both cases.
Also add WARM_RESET_L as one of the power signals for debug purpose.
BRANCH=none
BUG=b:78194018, b:112723105, b:112564635
TEST=Ran "dut-control warm_reset:on" and "dut-control warm_reset:off".
Scoped the signal of AP_RST_L and PS_HOLD to verify the correctness.
Verified AP hold and back booting up.
TEST=Changed to the gpio.inc to swap LID_OPEN and WARM_RESET_L and
ran "dut-control lid_open:no" and "dut-control lid_open:yes" to emualte
the case JTAG_SRST gets fused out. Scoped the signal correctness.
Verified AP hold and back booting up. Ran flashrom to program AP SPI
flash through servo.
Change-Id: I71ebd920171da9994192f7742675feb7cb39ce2f
Signed-off-by: Wai-Hong Tam <waihong@google.com>
Reviewed-on: https://chromium-review.googlesource.com/1234743
Diffstat (limited to 'power')
-rw-r--r-- | power/sdm845.c | 65 |
1 files changed, 64 insertions, 1 deletions
diff --git a/power/sdm845.c b/power/sdm845.c index 6c5f033b44..36e041f96d 100644 --- a/power/sdm845.c +++ b/power/sdm845.c @@ -89,6 +89,9 @@ static char power_button_was_pressed; /* 1 if lid-open event has been detected */ static char lid_opened; +/* 1 if AP_RST_L and PS_HOLD is overdriven by EC */ +static char ap_rst_overdriven; + /* * 1 if power state is controlled by special functions, like a console command * or an interrupt handler, for bypassing POWER_GOOD lost trigger. It is @@ -153,6 +156,64 @@ void chipset_reset_request_interrupt(enum gpio_signal signal) hook_call_deferred(&chipset_reset_request_handler_data, 0); } +void chipset_warm_reset_interrupt(enum gpio_signal signal) +{ + /* + * The warm_reset signal is pulled-up by a rail from PMIC. If the + * warm_reset drops, it means: + * * Servo or Cr50 holds the signal, or + * * its pull-up rail POWER_GOOD drops. + */ + if (!gpio_get_level(GPIO_WARM_RESET_L)) { + if (gpio_get_level(GPIO_POWER_GOOD)) { + /* + * Servo or Cr50 holds the WARM_RESET_L signal. + * + * Overdrive AP_RST_L to hold AP. Overdrive PS_HOLD to + * emulate AP being up to trick the PMIC into thinking + * there’s nothing weird going on. + */ + ap_rst_overdriven = 1; + gpio_set_flags(GPIO_PS_HOLD, GPIO_INT_BOTH | + GPIO_SEL_1P8V | GPIO_OUT_HIGH); + gpio_set_flags(GPIO_AP_RST_L, GPIO_INT_BOTH | + GPIO_SEL_1P8V | GPIO_OUT_LOW); + } else { + /* + * The pull-up rail POWER_GOOD drops. + * + * High-Z both AP_RST_L and PS_HOLD to restore their + * states. + */ + gpio_set_flags(GPIO_AP_RST_L, GPIO_INT_BOTH | + GPIO_SEL_1P8V); + gpio_set_flags(GPIO_PS_HOLD, GPIO_INT_BOTH | + GPIO_SEL_1P8V); + ap_rst_overdriven = 0; + } + } else { + if (ap_rst_overdriven) { + /* + * Servo or Cr50 releases the WARM_RESET_L signal. + * + * High-Z both AP_RST_L and PS_HOLD to restore their + * state. Cold reset the PMIC, doing S0->S5->S0 + * transition, to recover the system. + */ + gpio_set_flags(GPIO_AP_RST_L, GPIO_INT_BOTH | + GPIO_SEL_1P8V); + gpio_set_flags(GPIO_PS_HOLD, GPIO_INT_BOTH | + GPIO_SEL_1P8V); + ap_rst_overdriven = 0; + + /* TODO(b/112723105): Do S0->S5->S0 transition here. */ + } + /* If not overdriven, just a normal power-up, do nothing. */ + } + + power_signal_interrupt(signal); +} + static void sdm845_lid_event(void) { /* Power task only cares about lid-open events */ @@ -328,8 +389,10 @@ enum power_state power_chipset_init(void) int init_power_state; uint32_t reset_flags = system_get_reset_flags(); - /* Enable reboot control input from AP */ + /* Enable interrupts */ gpio_enable_interrupt(GPIO_AP_RST_REQ); + gpio_enable_interrupt(GPIO_WARM_RESET_L); + gpio_enable_interrupt(GPIO_POWER_GOOD); /* * Force the AP shutdown unless we are doing SYSJUMP. Otherwise, |