drivers: fuelgauge: Add Onsemi LC709203F driver

Add driver for the Onsemi LC709203F fuel gauge

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

Author: DBS06

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.

drivers/fuel_gauge/lc709203f/emul_lc709203f.c

@@ -0,0 +1,271 @@
+/*
+ * Copyright (c) 2025 Philipp Steiner <[email protected]>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Emulator for lc709203f fuel gauge
+ */
+
+#include <string.h>
+#define DT_DRV_COMPAT onnn_lc709203f
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(EMUL_LC709203F);
+
+#include <zephyr/device.h>
+#include <zephyr/drivers/emul.h>
+#include <zephyr/drivers/i2c.h>
+#include <zephyr/drivers/i2c_emul.h>
+#include <zephyr/sys/byteorder.h>
+#include <zephyr/sys/crc.h>
+
+#include "lc709203f.h"
+
+/* You can store as many registers as you need.
+ * Note: The LC709203F typically uses 16-bit registers.
+ */
+struct lc709203f_emul_data {
+	/* This emulator object (required for i2c_emul). */
+	struct i2c_emul emul;
+	/* The I2C emulation config (pointer to our dev_config). */
+	const struct i2c_emul_api *api;
+	/* A backing store for registers in the device. */
+	uint16_t regs[0x1B]; /* or enough to hold all used registers */
+};
+
+struct lc709203f_emul_cfg {
+	/** I2C address of emulator */
+	uint16_t addr;
+};
+
+/* Polynomial to calculate CRC-8-ATM */
+#define LC709203F_CRC_POLYNOMIAL 0x07
+
+/* Reset handler (optional). You can reset internal state here if desired. */
+static int lc709203f_emul_reset(const struct emul *target)
+{
+	struct lc709203f_emul_data *data = (struct lc709203f_emul_data *)target->data;
+
+	memset(data->regs, 0, sizeof(data->regs));
+
+	/* Set default values for registers that your real hardware starts with */
+	data->regs[LC709203F_REG_BEFORE_RSOC] = 0x0000;       /* - */
+	data->regs[LC709203F_REG_THERMISTOR_B] = 0x0D34;      /* B -constant */
+	data->regs[LC709203F_REG_INITIAL_RSOC] = 0x0000;      /* - */
+	data->regs[LC709203F_REG_CELL_TEMPERATURE] = 0x0BA6;  /* 25.0 °C 298.2 °K -> */
+	data->regs[LC709203F_REG_CELL_VOLTAGE] = 3700;        /* 3.7 V in mV */
+	data->regs[LC709203F_REG_CURRENT_DIRECTION] = 0x0000; /* Auto mode */
+	data->regs[LC709203F_REG_APA] = 0x0000;               /* - */
+	data->regs[LC709203F_REG_APT] = 0x001E;               /* initial value */
+	data->regs[LC709203F_REG_RSOC] = 50;                  /* 50% battery level */
+	data->regs[LC709203F_REG_CELL_ITE] = 500;             /* 50.0% battery level */
+	data->regs[LC709203F_REG_IC_VERSION] = 0x1234;        /* Example chip ID */
+	data->regs[LC709203F_REG_BAT_PROFILE] = 0x0000;       /* - */
+	data->regs[LC709203F_REG_ALARM_LOW_RSOC] = 0x0008;    /* 8% */
+	data->regs[LC709203F_REG_ALARM_LOW_VOLTAGE] = 0x0000; /* initial value */
+	data->regs[LC709203F_REG_IC_POWER_MODE] = 0x0002;     /* - */
+	data->regs[LC709203F_REG_STATUS_BIT] = 0x0000;        /* initial value */
+	data->regs[LC709203F_REG_NUM_PARAMETER] = 0x0301;     /* - */
+
+	return 0;
+}
+
+static int emul_lc709203f_reg_write(const struct emul *target, uint8_t *buf, size_t len)
+{
+	struct lc709203f_emul_data *data = target->data;
+	const struct lc709203f_emul_cfg *lc709203f_emul_cfg = target->cfg;
+	const uint8_t reg = buf[0];
+	const uint16_t value = sys_get_le16(&buf[1]);
+	const uint8_t crc = buf[3];
+	uint8_t crc_buf[4];
+
+	crc_buf[0] = lc709203f_emul_cfg->addr << 1;
+	crc_buf[1] = reg;
+	crc_buf[2] = buf[1];
+	crc_buf[3] = buf[2];
+
+	const uint8_t crc_calc = crc8(crc_buf, sizeof(crc_buf), LC709203F_CRC_POLYNOMIAL, 0, false);
+
+	if (crc != crc_calc) {
+		LOG_ERR("CRC mismatch on reg 0x%02x", reg);
+		return -EIO;
+	}
+
+	switch (reg) {
+	case LC709203F_REG_RSOC:
+		data->regs[LC709203F_REG_RSOC] = value;
+		data->regs[LC709203F_REG_CELL_ITE] = value / 10;
+		break;
+	case LC709203F_REG_BEFORE_RSOC:
+	case LC709203F_REG_THERMISTOR_B:
+	case LC709203F_REG_INITIAL_RSOC:
+	case LC709203F_REG_CELL_TEMPERATURE:
+	case LC709203F_REG_CURRENT_DIRECTION:
+	case LC709203F_REG_APA:
+	case LC709203F_REG_APT:
+	case LC709203F_REG_BAT_PROFILE:
+	case LC709203F_REG_ALARM_LOW_RSOC:
+	case LC709203F_REG_ALARM_LOW_VOLTAGE:
+	case LC709203F_REG_IC_POWER_MODE:
+	case LC709203F_REG_STATUS_BIT:
+		data->regs[reg] = value;
+		break;
+	default:
+		LOG_ERR("Unknown or read only register 0x%x write", reg);
+		return -EIO;
+	}
+
+	LOG_INF("write 0x%x", reg);
+	return 0;
+}
+
+static int emul_lc709203f_reg_read(const struct emul *target, int reg, uint8_t *buf, size_t len)
+{
+	struct lc709203f_emul_data *data = target->data;
+	const struct lc709203f_emul_cfg *lc709203f_emul_cfg = target->cfg;
+	uint16_t val = 0;
+
+	switch (reg) {
+	case LC709203F_REG_CELL_TEMPERATURE:
+		if (data->regs[LC709203F_REG_STATUS_BIT] == 0x0000) {
+			LOG_ERR("Temperature obtaining method is not set to Thermistor mode, "
+				"instead its set to I2C mode");
+			return -EIO;
+		}
+	case LC709203F_REG_THERMISTOR_B:
+	case LC709203F_REG_CELL_VOLTAGE:
+	case LC709203F_REG_CURRENT_DIRECTION:
+	case LC709203F_REG_APA:
+	case LC709203F_REG_APT:
+	case LC709203F_REG_RSOC:
+	case LC709203F_REG_CELL_ITE:
+	case LC709203F_REG_IC_VERSION:
+	case LC709203F_REG_BAT_PROFILE:
+	case LC709203F_REG_ALARM_LOW_RSOC:
+	case LC709203F_REG_ALARM_LOW_VOLTAGE:
+	case LC709203F_REG_IC_POWER_MODE:
+	case LC709203F_REG_STATUS_BIT:
+	case LC709203F_REG_NUM_PARAMETER:
+		val = data->regs[reg];
+		break;
+	default:
+		LOG_ERR("Unknown or write only register 0x%x read", reg);
+		return -EIO;
+	}
+
+	sys_put_le16(val, buf);
+
+	uint8_t crc_buf[5];
+
+	/* Build buffer for CRC calculation */
+	crc_buf[0] = lc709203f_emul_cfg->addr << 1;
+	crc_buf[1] = reg;
+	crc_buf[2] = (lc709203f_emul_cfg->addr << 1) | 0x01;
+	crc_buf[3] = buf[0]; /* LSB */
+	crc_buf[4] = buf[1]; /* MSB */
+
+	/* Calculate CRC and write it into the receive buffer */
+	buf[2] = crc8(crc_buf, sizeof(crc_buf), LC709203F_CRC_POLYNOMIAL, 0, false);
+
+	return 0;
+}
+
+static int lc709203f_emul_transfer_i2c(const struct emul *target, struct i2c_msg *msgs,
+				       int num_msgs, int addr)
+{
+	int reg;
+
+	__ASSERT_NO_MSG(msgs && num_msgs);
+
+	i2c_dump_msgs_rw(target->dev, msgs, num_msgs, addr, false);
+	switch (num_msgs) {
+	case 1:
+		if (msgs->flags & I2C_MSG_READ) {
+			LOG_ERR("Unexpected read");
+			return -EIO;
+		}
+
+		if (msgs->len == 4) {
+			return emul_lc709203f_reg_write(target, msgs->buf, msgs->len);
+		}
+
+		LOG_ERR("Unexpected msg length %d", msgs->len);
+		return -EIO;
+
+	case 2:
+		if (msgs->flags & I2C_MSG_READ) {
+			LOG_ERR("Unexpected read");
+			return -EIO;
+		}
+		if (msgs->len != 1) {
+			LOG_ERR("Unexpected msg0 length %d", msgs->len);
+			return -EIO;
+		}
+		reg = msgs->buf[0];
+
+		/* Now process the 'read' part of the message */
+		msgs++;
+		if (msgs->flags & I2C_MSG_READ) {
+			if (msgs->len == 3) {
+				return emul_lc709203f_reg_read(target, reg, msgs->buf, msgs->len);
+			}
+
+			LOG_ERR("Unexpected msg length %d", msgs->len);
+			return -EIO;
+		}
+		LOG_ERR("Second message must be an I2C write");
+		return -EIO;
+	default:
+		LOG_ERR("Invalid number of messages: %d", num_msgs);
+		return -EIO;
+	}
+
+	return 0;
+}
+/* The I2C emulator API required by Zephyr. */
+static const struct i2c_emul_api lc709203f_emul_api_i2c = {
+	.transfer = lc709203f_emul_transfer_i2c,
+};
+
+#ifdef CONFIG_ZTEST
+#include <zephyr/ztest.h>
+
+/* Add test reset handlers in when using emulators with tests */
+#define LC709203F_EMUL_RESET_RULE_BEFORE(inst) lc709203f_emul_reset(EMUL_DT_GET(DT_DRV_INST(inst)));
+
+static void lc709203f_gauge_reset_rule_after(const struct ztest_unit_test *test, void *data)
+{
+	ARG_UNUSED(test);
+	ARG_UNUSED(data);
+
+	DT_INST_FOREACH_STATUS_OKAY(LC709203F_EMUL_RESET_RULE_BEFORE)
+}
+ZTEST_RULE(lc709203f_gauge_reset, NULL, lc709203f_gauge_reset_rule_after);
+#endif /* CONFIG_ZTEST */
+
+/**
+ * Set up a new emulator (I2C)
+ *
+ * @param emul Emulation information
+ * @param parent Device to emulate
+ * @return 0 indicating success (always)
+ */
+static int lc709203f_emul_init(const struct emul *target, const struct device *parent)
+{
+	ARG_UNUSED(parent);
+	lc709203f_emul_reset(target);
+	return 0;
+}
+
+/*
+ * Main instantiation macro.
+ */
+#define DEFINE_LC709203F_EMUL(n)                                                                   \
+	static struct lc709203f_emul_data lc709203f_emul_data_##n;                                 \
+	static const struct lc709203f_emul_cfg lc709203f_emul_cfg_##n = {                          \
+		.addr = DT_INST_REG_ADDR(n),                                                       \
+	};                                                                                         \
+	EMUL_DT_INST_DEFINE(n, lc709203f_emul_init, &lc709203f_emul_data_##n,                      \
+			    &lc709203f_emul_cfg_##n, &lc709203f_emul_api_i2c, NULL)
+
+DT_INST_FOREACH_STATUS_OKAY(DEFINE_LC709203F_EMUL);