Feat |>[eta4662] Add eta4662 driver and read out the device id

Author: Jiyun-Yang

src/fw/drivers/battery/battery_obelix.c

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "drivers/battery.h"
+
+#include "drivers/exti.h"
+#include "drivers/gpio.h"
+#include "board/board.h"
+#include "drivers/otp.h"
+#include "drivers/periph_config.h"
+#include "system/logging.h"
+
+#include <mcu.h>
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "charger_eta4662.h"
+
+
+
+void battery_init(void) {
+  chager_init();
+}
+
+
+int battery_get_millivolts(void) {
+  //ADCVoltageMonitorReading info = battery_read_voltage_monitor();
+
+  // Apologies for the madness numbers.
+  // The previous implementation had some approximations in it. The battery voltage is scaled
+  // down by a pair of resistors (750k at the top, 470k at the bottom), resulting in a required
+  // scaling of (75 + 47) / 47 or roughly 2.56x, but the previous implementation also required
+  // fudging the numbers a bit in order to approximate for leakage current (a 73/64 multiple
+  // was arbitrarily increased to 295/256). In order to match this previous arbitrary scaling
+  // I've chosen new numbers that provide 2.62x scaling, which is the previous 2.56x with the
+  // same amount of fudging applied.
+
+  return 3600;//battery_convert_reading_to_millivolts(info, 3599, 1373);
+}
+

src/fw/drivers/battery/charger_eta4662.c

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "drivers/battery.h"
+#include "drivers/gpio.h"
+#include "drivers/pmic.h"
+#include "system/logging.h"
+#include "system/passert.h"
+#include "drivers/i2c.h"
+
+static bool prv_read_register(uint8_t register_address, uint8_t *result) {
+  i2c_use(I2C_ETA4662);
+  bool rv = i2c_read_register(I2C_ETA4662, register_address, result);
+  i2c_release(I2C_ETA4662);
+  return rv;
+}
+
+static bool prv_write_register(uint8_t register_address, uint8_t datum) {
+  i2c_use(I2C_ETA4662);
+  bool rv = i2c_write_register(I2C_ETA4662, register_address, datum);
+  i2c_release(I2C_ETA4662);
+  return rv;
+}
+
+void chager_init(void) {
+  // pmic_init() needs to happen, but I think it will happen elsewhere first
+  // It may be okay to just init the pmic here again
+  uint8_t rv;
+  bool found = prv_read_register(0x0B, &rv);
+  if (found) {
+    PBL_LOG(LOG_LEVEL_DEBUG, "Found ETA4662 with ID register ID:%02x", rv);
+  } else {
+    PBL_LOG(LOG_LEVEL_ERROR, "Failed to read the ETA4662 ID register");
+  }
+  return;
+}
+
+
+bool battery_charge_controller_thinks_we_are_charging_impl(void) {
+  return false;//pmic_is_charging();
+}
+
+bool battery_is_usb_connected_impl(void) {
+  return false;//pmic_is_usb_connected();
+}
+
+void battery_set_charge_enable(bool charging_enabled) {
+  //pmic_set_charger_state(charging_enabled);
+}
+
+// TODO
+// This is my understanding from Figure 9 of the datasheet:
+// Charger off -> Pre charge -> Fast Charge (constant current) ->
+// Fast Charge (constant voltage) -> Maintain Charge -> Maintain Charge Done
+//
+// The Pre Charge and Charge Termination currents are programmed via I2C
+// The Fast Charge current is determined by Rset
+//
+// There doesn't seem to be a way to change the current in constant current mode
+void battery_set_fast_charge(bool fast_charge_enabled) {
+
+}

src/fw/drivers/battery/charger_eta4662.h

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+extern void chager_init(void);

src/fw/drivers/wscript_build

@@ -214,6 +214,7 @@ elif bld.is_obelix_bb():
             'driver_motor',
             'driver_imu',
             'driver_touch',
+            'driver_battery'
         ],
     ) 
 elif bld.is_obelix():
@@ -227,6 +228,7 @@ elif bld.is_obelix():
             'driver_flash',
             'driver_gpio_defaults',
             'driver_imu'
+            'driver_battery'
         ],
     )    
 
@@ -419,6 +421,29 @@ elif bld.is_asterix():
             'root_includes',
         ],
     )
+elif bld.is_obelix_bb():
+    bld.objects(
+        name='driver_battery',
+        source=[
+            'battery/battery_obelix.c',
+            'battery/charger_eta4662.c',
+        ],
+        use=[
+            'fw_includes',
+            'root_includes',
+        ],
+    )
+elif bld.is_obelix():
+    bld.objects(
+        name='driver_battery',
+        source=[
+            'sf32lb/stubs/battery.c',
+        ],
+        use=[
+            'fw_includes',
+            'root_includes',
+        ],
+    )
 else:
     bld.objects(
         name='driver_battery',
@@ -1644,7 +1669,7 @@ if mcu_family == 'SF32LB':
             'flash/cd_flash_driver.c',
             'battery/battery_common.c',
             # 'display/jdi/jdi.c',
-            'sf32lb/stubs/battery.c',
+            #'sf32lb/stubs/battery.c',
             'i2c.c',
             'sf32lb/i2c_hal.c',
             'sf32lb/pwm.c',