pwrctl: Add latch output to power control
On the Zaius machine, the BMC signals that power up the CPU are gated by
a latch to protect against GPIO blips during BMC reset/power loss.
This adds an optional power GPIO configuration that controls the latch's
enable pin. Its behavior is to assert high when the op-pwrctl runs,
allowing power_up lines to propagate past their latches.
Signed-off-by: Xo Wang <xow@google.com>
Change-Id: Ibf0d1db771033cb9bba82575cca1bd21cfb3ad3d
diff --git a/libopenbmc_intf/power_gpio.c b/libopenbmc_intf/power_gpio.c
index 3f4b5a8..543281f 100644
--- a/libopenbmc_intf/power_gpio.c
+++ b/libopenbmc_intf/power_gpio.c
@@ -28,6 +28,7 @@
GError *error;
GVariant *value;
gchar *power_good_in_name;
+ gchar *latch_out_name;
GVariantIter *power_up_outs_iter;
GVariantIter *reset_outs_iter;
gchar *power_up_out_name;
@@ -66,9 +67,13 @@
g_assert(value != NULL);
memset(power_gpio, 0, sizeof(*power_gpio));
- g_variant_get(value, "(&sa(sb)a(sb))", &power_good_in_name,
- &power_up_outs_iter, &reset_outs_iter);
+ g_variant_get(value, "(&s&sa(sb)a(sb))", &power_good_in_name, &latch_out_name,
+ &power_up_outs_iter, &reset_outs_iter);
+ g_print("Power GPIO latch output %s\n", latch_out_name);
+ if(*latch_out_name != '\0') { /* latch is optional */
+ power_gpio->latch_out.name = strdup(latch_out_name);
+ }
g_print("Power GPIO power good input %s\n", power_good_in_name);
power_gpio->power_good_in.name = g_strdup(power_good_in_name);
power_gpio->num_power_up_outs = g_variant_iter_n_children(
@@ -109,6 +114,7 @@
void free_power_gpio(PowerGpio *power_gpio) {
int i;
+ g_free(power_gpio->latch_out.name);
g_free(power_gpio->power_good_in.name);
for(i = 0; i < power_gpio->num_power_up_outs; i++) {
g_free(power_gpio->power_up_outs[i].name);
diff --git a/libopenbmc_intf/power_gpio.h b/libopenbmc_intf/power_gpio.h
index f36a722..77e1c9c 100644
--- a/libopenbmc_intf/power_gpio.h
+++ b/libopenbmc_intf/power_gpio.h
@@ -23,6 +23,8 @@
#include "gpio.h"
typedef struct PowerGpio {
+ /* Optional active high pin enabling writes to latched power_up pins. */
+ GPIO latch_out; /* NULL name if not used. */
/* Active high pin that is asserted following successful host power up. */
GPIO power_good_in;
/* Selectable polarity pins enabling host power rails. */
diff --git a/op-pwrctl/power_control_obj.c b/op-pwrctl/power_control_obj.c
index cd13c68..679493c 100644
--- a/op-pwrctl/power_control_obj.c
+++ b/op-pwrctl/power_control_obj.c
@@ -208,6 +208,12 @@
uint8_t pgood_state;
// get gpio device paths
+ if(power_gpio->latch_out.name != NULL) { /* latch is optional */
+ rc = gpio_init(connection, &power_gpio->latch_out);
+ if(rc != GPIO_OK) {
+ error = rc;
+ }
+ }
rc = gpio_init(connection, &power_gpio->power_good_in);
if(rc != GPIO_OK) {
error = rc;
@@ -225,6 +231,26 @@
}
}
+ /* If there's a latch, it only needs to be set once. */
+ if(power_gpio->latch_out.name != NULL) {
+ do {
+ rc = gpio_open(&power_gpio->latch_out);
+ if(rc != GPIO_OK) {
+ /* Failures are non-fatal. */
+ break;
+ }
+ rc = gpio_write(&power_gpio->latch_out, 1);
+ gpio_close(&power_gpio->latch_out);
+ } while(0);
+ if (rc != GPIO_OK) {
+ error = rc;
+ g_print("PowerControl ERROR failed to assert latch %s rc=%d\n",
+ power_gpio->latch_out.name, rc);
+ } else {
+ g_print("PowerControl asserted latch %s\n", power_gpio->latch_out.name);
+ }
+ }
+
rc = gpio_open(&power_gpio->power_good_in);
if(rc != GPIO_OK) {
return rc;
diff --git a/pysystemmgr/system_manager.py b/pysystemmgr/system_manager.py
index 5ecc14f..6f4bf81 100644
--- a/pysystemmgr/system_manager.py
+++ b/pysystemmgr/system_manager.py
@@ -180,12 +180,13 @@
return r
@dbus.service.method(DBUS_NAME, in_signature='',
- out_signature='sa(sb)a(sb)')
+ out_signature='ssa(sb)a(sb)')
def getPowerConfiguration(self):
power_good_in = System.POWER_CONFIG.get('power_good_in', '')
+ latch_out = System.POWER_CONFIG.get('latch_out', '')
power_up_outs = System.POWER_CONFIG.get('power_up_outs', [])
reset_outs = System.POWER_CONFIG.get('reset_outs', [])
- r = [power_good_in, power_up_outs, reset_outs]
+ r = [power_good_in, latch_out, power_up_outs, reset_outs]
print "Power GPIO config: " + str(r)
return r