power: Also ask charger if charge done

Also check the actual charge controller bq25896's CHRG_STAT to see if
charging is complete.  Don't only rely on the battery fuel gauge
bq27220 reaching 100% to indicate charging is finished.

This more accurately reflects the actual charging status and
simplifies optionally reducing the battery charging voltage limit.
Keeping the fuel gauge check ensures that dis/connecting from USB will
still show as fully charged at default settings (no charge limit),
since the bq25896 takes a few seconds to detect charging is complete.

This adds a new function to the API:
furi_hal_power_is_charging_done()

Helps with #1158.

applications/services/power/power_service/power.c

@@ -99,7 +99,7 @@ void power_free(Power* power) {
 
 static void power_check_charging_state(Power* power) {
     if(furi_hal_power_is_charging()) {
-        if(power->info.charge == 100) {
+        if((power->info.charge == 100) || (furi_hal_power_is_charging_done())) {
             if(power->state != PowerStateCharged) {
                 notification_internal_message(power->notification, &sequence_charged);
                 power->state = PowerStateCharged;

firmware/targets/f7/api_symbols.csv

@@ -1,5 +1,5 @@
 entry,status,name,type,params
-Version,+,1.6,,
+Version,+,1.7,,
 Header,+,applications/services/bt/bt_service/bt.h,,
 Header,+,applications/services/cli/cli.h,,
 Header,+,applications/services/cli/cli_vcp.h,,
@@ -1141,6 +1141,7 @@ Function,+,furi_hal_power_insomnia_enter,void,
 Function,+,furi_hal_power_insomnia_exit,void,
 Function,-,furi_hal_power_insomnia_level,uint16_t,
 Function,+,furi_hal_power_is_charging,_Bool,
+Function,+,furi_hal_power_is_charging_done,_Bool,
 Function,+,furi_hal_power_is_otg_enabled,_Bool,
 Function,+,furi_hal_power_off,void,
 Function,+,furi_hal_power_reset,void,

firmware/targets/f7/furi_hal/furi_hal_power.c

@@ -266,6 +266,13 @@ bool furi_hal_power_is_charging() {
     return ret;
 }
 
+bool furi_hal_power_is_charging_done() {
+    furi_hal_i2c_acquire(&furi_hal_i2c_handle_power);
+    bool ret = bq25896_is_charging_done(&furi_hal_i2c_handle_power);
+    furi_hal_i2c_release(&furi_hal_i2c_handle_power);
+    return ret;
+}
+
 void furi_hal_power_shutdown() {
     furi_hal_power_insomnia_enter();
 

firmware/targets/furi_hal_include/furi_hal_power.h

@@ -85,6 +85,12 @@ uint8_t furi_hal_power_get_bat_health_pct();
  */
 bool furi_hal_power_is_charging();
 
+/** Get charge complete status
+ *
+ * @return     true if done charging and connected to charger
+ */
+bool furi_hal_power_is_charging_done();
+
 /** Switch MCU to SHUTDOWN */
 void furi_hal_power_shutdown();
 

lib/drivers/bq25896.c

@@ -81,7 +81,7 @@ void bq25896_poweroff(FuriHalI2cBusHandle* handle) {
         handle, BQ25896_ADDRESS, 0x09, *(uint8_t*)&bq25896_regs.r09, BQ25896_I2C_TIMEOUT);
 }
 
-bool bq25896_is_charging(FuriHalI2cBusHandle* handle) {
+ChrgStat bq25896_get_charge_status(FuriHalI2cBusHandle* handle) {
     furi_hal_i2c_read_mem(
         handle,
         BQ25896_ADDRESS,
@@ -91,7 +91,16 @@ bool bq25896_is_charging(FuriHalI2cBusHandle* handle) {
         BQ25896_I2C_TIMEOUT);
     furi_hal_i2c_read_reg_8(
         handle, BQ25896_ADDRESS, 0x0B, (uint8_t*)&bq25896_regs.r0B, BQ25896_I2C_TIMEOUT);
-    return bq25896_regs.r0B.CHRG_STAT != ChrgStatNo;
+    return bq25896_regs.r0B.CHRG_STAT;
+}
+
+bool bq25896_is_charging(FuriHalI2cBusHandle* handle) {
+    // Include precharge, fast charging, and charging termination done as "charging"
+    return bq25896_get_charge_status(handle) != ChrgStatNo;
+}
+
+bool bq25896_is_charging_done(FuriHalI2cBusHandle* handle) {
+    return bq25896_get_charge_status(handle) == ChrgStatDone;
 }
 
 void bq25896_enable_charging(FuriHalI2cBusHandle* handle) {

lib/drivers/bq25896.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#include "bq25896_reg.h"
+
 #include <stdbool.h>
 #include <stdint.h>
 #include <furi_hal_i2c.h>
@@ -10,9 +12,15 @@ void bq25896_init(FuriHalI2cBusHandle* handle);
 /** Send device into shipping mode */
 void bq25896_poweroff(FuriHalI2cBusHandle* handle);
 
+/** Get charging status */
+ChrgStat bq25896_get_charge_status(FuriHalI2cBusHandle* handle);
+
 /** Is currently charging */
 bool bq25896_is_charging(FuriHalI2cBusHandle* handle);
 
+/** Is charging completed while connected to charger */
+bool bq25896_is_charging_done(FuriHalI2cBusHandle* handle);
+
 /** Enable charging */
 void bq25896_enable_charging(FuriHalI2cBusHandle* handle);