drivers: fuelgauge: Add Onsemi LC709203F driver

Add driver for the Onsemi LC709203F fuel gauge

Signed-off-by: Philipp Steiner <[email protected]>

Author: DBS06

boards/adafruit/feather_esp32s2/doc/adafruit_feather_esp32s2.rst

@@ -16,7 +16,7 @@ Hardware
 - 320KB SRAM, 4MB flash + 2MB PSRAM
 - USB-C directly connected to the ESP32-S2 for USB
 - LiPo connector and built-in battery charging when powered via USB-C
-- LC709203 or MAX17048 fuel gauge for battery voltage and state-of-charge reporting
+- LC709203F or MAX17048 fuel gauge for battery voltage and state-of-charge reporting
 - Built-in NeoPixel indicator RGB LED
 - STEMMA QT connector for I2C devices, with switchable power for low-power mode
 
@@ -28,12 +28,10 @@ Hardware
      overlay. All boards, except the `Adafruit ESP32-S2 Feather with BME280 Sensor`_ have a
      space for it, but will not be shipped with.
    - As of May 31, 2023 - Adafruit has changed the battery monitor chip from the
-     now-discontinued LC709203 to the MAX17048. Check the back silkscreen of your Feather to
+     now-discontinued LC709203F to the MAX17048. Check the back silkscreen of your Feather to
      see which chip you have.
-   - For the MAX17048 a driver in zephyr exists and is supported, but needs to be added via
-     a devicetree overlay.
-   - For the LC709203 a driver does'nt exists yet and the fuel gauge for boards with this IC
-     is not available.
+   - For the MAX17048 and LC709203F a driver in zephyr exists and is supported, but needs to be
+     added via a devicetree overlay.
    - For the `Adafruit ESP32-S2 Feather`_ there are two different Revisions ``rev B`` and
      ``rev C``. The ``rev C`` board has revised the power circuitry for the NeoPixel and I2C
      QT port. Instead of a transistor the ``rev C`` has a LDO regulator. To enable the
@@ -311,14 +309,38 @@ There is a sample available to verify that the MAX17048 fuel gauge on the board
 functioning correctly with Zephyr:
 
 .. note::
-   As of May 31, 2023 Adafruit changed the battery monitor chip from the now-discontinued LC709203
+   As of May 31, 2023 Adafruit changed the battery monitor chip from the now-discontinued LC709203F
    to the MAX17048.
 
 .. zephyr-app-commands::
    :zephyr-app: samples/fuel_gauge/max17048/
    :board: adafruit_feather_esp32s2@C
    :goals: build flash
 
+Testing the Fuel Gauge (LC709203F)
+*********************************
+
+There is a sample available to verify that the LC709203F fuel gauge on the board are
+functioning correctly with Zephyr:
+
+.. note::
+   As of May 31, 2023 Adafruit changed the battery monitor chip from the now-discontinued LC709203F
+   to the MAX17048.
+
+**Rev B**
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/fuel_gauge/lc709203f/
+   :board: adafruit_feather_esp32s2@B
+   :goals: build flash
+
+**Rev C**
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/fuel_gauge/lc709203f/
+   :board: adafruit_feather_esp32s2@C
+   :goals: build flash
+
 Testing Wi-Fi
 *************
 

boards/adafruit/feather_esp32s2/doc/adafruit_feather_esp32s2_tft.rst

@@ -16,7 +16,7 @@ Hardware
 - 320KB SRAM, 4MB flash + 2MB PSRAM
 - USB-C directly connected to the ESP32-S2 for USB
 - LiPo connector and built-in battery charging when powered via USB-C
-- LC709203 or MAX17048 fuel gauge for battery voltage and state-of-charge reporting
+- LC709203F or MAX17048 fuel gauge for battery voltage and state-of-charge reporting
 - Charging indicator LED, user LED, reset and boot buttons.
 - Built-in NeoPixel indicator RGB LED
 - STEMMA QT connector for I2C devices, with switchable power for low-power mode
@@ -26,12 +26,10 @@ Hardware
 
    - The board has a space for a BME280, but will not be shipped with.
    - As of May 31, 2023 - Adafruit has changed the battery monitor chip from the
-     now-discontinued LC709203 to the MAX17048. Check the back silkscreen of your Feather to
+     now-discontinued LC709203F to the MAX17048. Check the back silkscreen of your Feather to
      see which chip you have.
-   - For the MAX17048 a driver in zephyr exists and is supported, but needs to be added via
-     a devicetree overlay.
-   - For the LC709203 a driver does'nt exists yet and the fuel gauge for boards with this IC
-     is not available.
+   - For the MAX17048 and LC709203F a driver in zephyr exists and is supported, but needs to be
+     added via a devicetree overlay.
 
 Supported Features
 ==================
@@ -259,14 +257,29 @@ There is a sample available to verify that the MAX17048 fuel gauge on the board
 functioning correctly with Zephyr:
 
 .. note::
-   As of May 31, 2023 Adafruit changed the battery monitor chip from the now-discontinued LC709203
+   As of May 31, 2023 Adafruit changed the battery monitor chip from the now-discontinued LC709203F
    to the MAX17048.
 
 .. zephyr-app-commands::
    :zephyr-app: samples/fuel_gauge/max17048/
    :board: adafruit_feather_esp32s2_tft
    :goals: build flash
 
+Testing the Fuel Gauge (LC709203F)
+*********************************
+
+There is a sample available to verify that the LC709203F fuel gauge on the board are
+functioning correctly with Zephyr:
+
+.. note::
+   As of May 31, 2023 Adafruit changed the battery monitor chip from the now-discontinued LC709203F
+   to the MAX17048.
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/fuel_gauge/lc709203f/
+   :board: adafruit_feather_esp32s2_tft
+   :goals: build flash
+
 Testing Wi-Fi
 *************
 

boards/adafruit/feather_esp32s2/doc/adafruit_feather_esp32s2_tft_reverse.rst

@@ -16,7 +16,7 @@ Hardware
 - 320KB SRAM, 4MB flash + 2MB PSRAM
 - USB-C directly connected to the ESP32-S2 for USB
 - LiPo connector and built-in battery charging when powered via USB-C
-- LC709203 or MAX17048 fuel gauge for battery voltage and state-of-charge reporting
+- MAX17048 fuel gauge for battery voltage and state-of-charge reporting
 - Charging indicator LED, user LED, reset and boot buttons and has 2 additional buttons.
 - Built-in NeoPixel indicator RGB LED
 - 240x135 pixel IPS TFT color display with 1.14" diagonal and ST7789 chipset.
@@ -255,10 +255,6 @@ Testing the Fuel Gauge (MAX17048)
 There is a sample available to verify that the MAX17048 fuel gauge on the board are
 functioning correctly with Zephyr:
 
-.. note::
-   As of May 31, 2023 Adafruit changed the battery monitor chip from the now-discontinued LC709203
-   to the MAX17048.
-
 .. zephyr-app-commands::
    :zephyr-app: samples/fuel_gauge/max17048/
    :board: adafruit_feather_esp32s2_tft_reverse

drivers/fuel_gauge/CMakeLists.txt

@@ -6,6 +6,7 @@ add_subdirectory_ifdef(CONFIG_SBS_GAUGE_NEW_API		sbs_gauge)
 add_subdirectory_ifdef(CONFIG_FUEL_GAUGE_COMPOSITE	composite)
 add_subdirectory_ifdef(CONFIG_MAX17048		max17048)
 add_subdirectory_ifdef(CONFIG_BQ27Z746		bq27z746)
+add_subdirectory_ifdef(CONFIG_LC709203F		lc709203f)
 
 zephyr_library_sources_ifdef(CONFIG_USERSPACE fuel_gauge_syscall_handlers.c)
 

drivers/fuel_gauge/Kconfig

@@ -23,5 +23,6 @@ source "drivers/fuel_gauge/max17048/Kconfig"
 source "drivers/fuel_gauge/sbs_gauge/Kconfig"
 source "drivers/fuel_gauge/bq27z746/Kconfig"
 source "drivers/fuel_gauge/composite/Kconfig"
+source "drivers/fuel_gauge/lc709203f/Kconfig"
 
 endif # FUEL_GAUGE

drivers/fuel_gauge/lc709203f/CMakeLists.txt

@@ -0,0 +1,6 @@
+zephyr_library()
+
+zephyr_library_sources(lc709203f.c)
+
+zephyr_include_directories_ifdef(CONFIG_EMUL_LC709203F .)
+zephyr_library_sources_ifdef(CONFIG_EMUL_LC709203F ./emul_lc709203f.c)

drivers/fuel_gauge/lc709203f/Kconfig

@@ -0,0 +1,20 @@
+# Copyright (c) 2025 Philipp Steiner <[email protected]>
+#
+# SPDX-License-Identifier: Apache-2.0
+
+config LC709203F
+	bool "LC709203F Fuel Gauge"
+	default y
+	depends on DT_HAS_ONNN_LC709203F_ENABLED
+	select I2C
+	help
+	  Enable I2C-based driver for LC709203F Fuel Gauge.
+
+config EMUL_LC709203F
+	bool "Emulate an LC709203F fuel gague"
+	default y
+	depends on EMUL
+	depends on LC709203F
+	help
+	  It provides readings which follow a simple sequence, thus allowing
+	  test code to check that things are working as expected.