feat(core): rework soc limit to battery model dependant soc target.

[no changelog]

core/embed/sys/power_manager/inc/sys/power_manager.h

@@ -193,11 +193,21 @@ pm_status_t pm_charging_disable(void);
 pm_status_t pm_charging_set_max_current(uint16_t current_ma);
 
 /**
- * @brief Set the battery State of Charge limit for operations
- * @param limit SoC limit percentage (0-100%)
+ * @brief Set the battery State of Charge precharge target.
+ *
+ * Charging controller will continously compare taget SoC charging voltage from
+ * battery model (temperature dependant) with the actual battery voltage and if
+ * the battery voltage is above the target, charging is stopped. If the battery
+ * voltage also cross the charging voltage target, Fuel gauge SoC estimate is
+ * enforced with the target value.
+ *
+ * Setting value to `100` disables the precharge target and charging cycle will
+ * be driven with PMIC driver.
+ *
+ * @param target SoC target percentage (0-100%)
  * @return pm_status_t Status code indicating success or failure
  */
-pm_status_t pm_set_soc_limit(uint8_t limit);
+pm_status_t pm_set_soc_target(uint8_t target);
 
 /**
  * @brief Suspends driver activity so the CPU can enter low-power mode.

core/embed/sys/power_manager/stm32u5/power_manager.c

@@ -156,8 +156,8 @@ pm_status_t pm_init(bool inherit_state) {
   // Enable charging by default to max current
   drv->charging_enabled = true;
 
-  // Set default SOC limit and max charging current limit
-  drv->soc_limit = 100;
+  // Set default SOC target and max charging current limit
+  drv->soc_target = 100;
   drv->charging_current_max_limit_ma = PM_BATTERY_CHARGING_CURRENT_MAX;
 
   // Fuel gauge SoC available, set fuel_gauge initialized.
@@ -527,23 +527,19 @@ static bool pm_load_recovery_data(pm_recovery_data_t* recovery) {
   return true;
 }
 
-pm_status_t pm_set_soc_limit(uint8_t limit) {
+pm_status_t pm_set_soc_target(uint8_t target) {
   pm_driver_t* drv = &g_pm;
 
   if (!drv->initialized) {
     return PM_NOT_INITIALIZED;
   }
 
-  if (limit > 100) {
-    return PM_ERROR;
-  }
-
-  if (limit <= PM_SOC_LIMIT_HYSTERESIS) {
+  if (target > 100) {
     return PM_ERROR;
   }
 
   irq_key_t irq_key = irq_lock();
-  drv->soc_limit = limit;
+  drv->soc_target = target;
   irq_unlock(irq_key);
 
   return PM_OK;

core/embed/sys/power_manager/stm32u5/power_manager_internal.h

@@ -35,7 +35,6 @@
 #define PM_BATTERY_UNDERVOLT_RECOVERY_THR_V 3.1f
 #define PM_BATTERY_UNDERVOLT_RECOVERY_WPC_THR_V 3.2f
 #define PM_BATTERY_LOW_THRESHOLD_SOC 15
-#define PM_SOC_LIMIT_HYSTERESIS 5
 #define PM_BATTERY_CHARGING_CURRENT_MAX PMIC_CHARGING_LIMIT_MAX
 #define PM_BATTERY_CHARGING_CURRENT_MIN PMIC_CHARGING_LIMIT_MIN
 #define PM_BATTERY_SAMPLING_BUF_SIZE 10
@@ -85,8 +84,9 @@ typedef struct {
   uint8_t bat_sampling_buf_tail_idx;
   uint8_t bat_sampling_buf_head_idx;
   uint8_t soc_ceiled;
-  uint8_t soc_limit;
-  bool soc_limit_reached;
+
+  uint8_t soc_target;
+  bool soc_target_reached;
 
   // Battery charging state
   bool charging_enabled;

core/embed/sys/power_manager/stm32u5/power_monitoring.c

@@ -24,6 +24,7 @@
 #include <sys/systick.h>
 #include <trezor_rtl.h>
 
+#include "../fuel_gauge/battery_model.h"
 #include "../fuel_gauge/fuel_gauge.h"
 #include "../stwlc38/stwlc38.h"
 #include "power_manager_internal.h"
@@ -167,15 +168,33 @@ void pm_charging_controller(pm_driver_t* drv) {
     pmic_set_charging_limit(drv->charging_current_target_ma);
   }
 
-  if ((drv->soc_ceiled >= drv->soc_limit) && (drv->soc_limit != 100)) {
-    drv->soc_limit_reached = true;
-  } else if ((drv->soc_limit == 100) ||
-             (drv->soc_ceiled < (drv->soc_limit - PM_SOC_LIMIT_HYSTERESIS))) {
-    drv->soc_limit_reached = false;
+  if (drv->soc_target == 100) {
+    drv->soc_target_reached = false;
+  } else {
+    // Translate SoC target to charging voltage via battery model
+    float target_ocv_voltage_v =
+        battery_ocv(drv->soc_target / 100.0f, drv->pmic_data.ntc_temp, false);
+
+    float battery_ocv_v = battery_meas_to_ocv(
+        drv->pmic_data.vbat, drv->pmic_data.ibat, drv->pmic_data.ntc_temp);
+
+    if (battery_ocv_v > target_ocv_voltage_v) {
+      // current voltage is within tight bounds of target voltage,
+      // we may also force SoC estimate to target value.
+      if (battery_ocv_v < target_ocv_voltage_v + 0.15) {
+        fuel_gauge_set_soc(&drv->fuel_gauge,
+                           (drv->soc_target / 100.0f) - 0.0001f,
+                           drv->fuel_gauge.P);
+      }
+
+      drv->soc_target_reached = true;
+
+    } else if (drv->soc_ceiled < drv->soc_target) {
+      drv->soc_target_reached = false;
+    }
   }
 
-  if (drv->soc_limit_reached) {
-    // Set charging current limit to 0
+  if (drv->soc_target_reached) {
     drv->charging_current_target_ma = 0;
   }