charger: add a driver for bq25180

Add a driver for the TI BQ25180. Implement enable/disable and current
set/get.

Signed-off-by: Fabio Baltieri <fabiobaltieri@google.com>

drivers/charger/CMakeLists.txt

@@ -4,6 +4,7 @@ zephyr_library()
 zephyr_syscall_header(${ZEPHYR_BASE}/include/zephyr/drivers/charger.h)
 
 zephyr_library_sources_ifdef(CONFIG_CHARGER_BQ24190 charger_bq24190.c)
+zephyr_library_sources_ifdef(CONFIG_CHARGER_BQ25180 charger_bq25180.c)
 zephyr_library_sources_ifdef(CONFIG_CHARGER_MAX20335 charger_max20335.c)
 zephyr_library_sources_ifdef(CONFIG_SBS_CHARGER sbs_charger.c)
 zephyr_library_sources_ifdef(CONFIG_USERSPACE charger_handlers.c)

drivers/charger/Kconfig

@@ -21,6 +21,7 @@ config CHARGER_INIT_PRIORITY
 
 source "drivers/charger/Kconfig.sbs_charger"
 source "drivers/charger/Kconfig.bq24190"
+source "drivers/charger/Kconfig.bq25180"
 source "drivers/charger/Kconfig.max20335"
 
 endif # CHARGER

drivers/charger/Kconfig.bq25180

@@ -0,0 +1,11 @@
+# Copyright 2024 Google LLC
+#
+# SPDX-License-Identifier: Apache-2.0
+
+config CHARGER_BQ25180
+	bool "BQ25180 Battery Charger"
+	default y
+	depends on DT_HAS_TI_BQ25180_ENABLED
+	select I2C
+	help
+	  Enable BQ25180 battery charger driver.

drivers/charger/charger_bq25180.c

@@ -0,0 +1,218 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * BQ25180 Datasheet: https://www.ti.com/lit/gpn/bq25180
+ */
+
+#define DT_DRV_COMPAT ti_bq25180
+
+#include <zephyr/device.h>
+#include <zephyr/drivers/charger.h>
+#include <zephyr/drivers/i2c.h>
+#include <zephyr/kernel.h>
+#include <zephyr/logging/log.h>
+#include <zephyr/sys/util.h>
+
+LOG_MODULE_REGISTER(bq25180, CONFIG_CHARGER_LOG_LEVEL);
+
+#define BQ25180_STAT0 0x00
+#define BQ25180_STAT1 0x01
+#define BQ25180_FLAG0 0x02
+#define BQ25180_VBAT_CTRL 0x03
+#define BQ25180_ICHG_CTRL 0x04
+#define BQ25180_IC_CTRL 0x07
+#define BQ25180_SHIP_RST 0x09
+#define BQ25180_MASK_ID 0x0c
+
+#define BQ25180_ICHG_CHG_DIS BIT(7)
+#define BQ25180_ICHG_MSK GENMASK(6, 0)
+#define BQ25180_WATCHDOG_SEL_1_MSK GENMASK(1, 0)
+#define BQ25180_WATCHDOG_DISABLE 0x03
+#define BQ25180_DEVICE_ID_MSK GENMASK(3, 0)
+#define BQ25180_DEVICE_ID 0x00
+#define BQ25180_SHIP_RST_EN_RST_SHIP_MSK GENMASK(6, 5)
+#define BQ25180_SHIP_RST_EN_RST_SHIP_ADAPTER 0x20
+#define BQ25180_SHIP_RST_EN_RST_SHIP_BUTTON 0x40
+
+/* Charging current limits */
+#define BQ25180_CURRENT_MIN_MA 5
+#define BQ25180_CURRENT_MAX_MA 1000
+
+struct bq25180_config {
+	struct i2c_dt_spec i2c;
+	uint32_t initial_current_microamp;
+};
+
+/*
+ * For ICHG <= 35mA = ICHGCODE + 5mA
+ * For ICHG > 35mA = 40 + ((ICHGCODE-31)*10)mA.
+ * Maximum programmable current = 1000mA
+ *
+ * Return: value between 0 and 127, negative on error.
+ */
+static int bq25180_ma_to_ichg(uint32_t current_ma, uint8_t *ichg)
+{
+	if (!IN_RANGE(current_ma, BQ25180_CURRENT_MIN_MA, BQ25180_CURRENT_MAX_MA)) {
+		LOG_WRN("charging current out of range: %dmA, "
+			"clamping to the nearest limit", current_ma);
+	}
+	current_ma = CLAMP(current_ma, BQ25180_CURRENT_MIN_MA, BQ25180_CURRENT_MAX_MA);
+
+	if (current_ma <= 35) {
+		*ichg = current_ma - 5;
+		return 0;
+	}
+
+	*ichg = (current_ma - 40) / 10 + 31;
+
+	return 0;
+}
+
+static uint32_t bq25180_ichg_to_ma(uint8_t ichg)
+{
+	ichg &= BQ25180_ICHG_MSK;
+
+	if (ichg <= 30) {
+		return (ichg + 5);
+	}
+
+	return (ichg - 31) * 10 + 40;
+}
+
+static int bq25183_charge_enable(const struct device *dev, const bool enable)
+{
+	const struct bq25180_config *cfg = dev->config;
+	uint8_t value = enable ? 0 : BQ25180_ICHG_CHG_DIS;
+	int ret;
+
+	ret = i2c_reg_update_byte_dt(&cfg->i2c, BQ25180_ICHG_CTRL,
+				     BQ25180_ICHG_CHG_DIS, value);
+	if (ret < 0) {
+		return ret;
+	}
+
+	return 0;
+}
+
+static int bq25180_set_charge_current(const struct device *dev,
+				      uint32_t const_charge_current_ua)
+{
+	const struct bq25180_config *cfg = dev->config;
+	uint8_t val;
+	int ret;
+
+	ret = bq25180_ma_to_ichg(const_charge_current_ua / 1000, &val);
+	if (ret < 0) {
+		return ret;
+	}
+
+	ret = i2c_reg_update_byte_dt(&cfg->i2c, BQ25180_ICHG_CTRL,
+				     BQ25180_ICHG_MSK, val);
+	if (ret < 0) {
+		return ret;
+	}
+
+	return 0;
+}
+
+static int bq25180_get_charge_current(const struct device *dev,
+				      uint32_t *const_charge_current_ua)
+{
+	const struct bq25180_config *cfg = dev->config;
+	uint8_t val;
+	int ret;
+
+	ret = i2c_reg_read_byte_dt(&cfg->i2c, BQ25180_ICHG_CTRL, &val);
+	if (ret < 0) {
+		return ret;
+	}
+
+	*const_charge_current_ua = bq25180_ichg_to_ma(val) * 1000;
+
+	return 0;
+}
+
+static int bq25180_get_prop(const struct device *dev, charger_prop_t prop,
+			    union charger_propval *val)
+{
+	switch (prop) {
+	case CHARGER_PROP_CONSTANT_CHARGE_CURRENT_UA:
+		return bq25180_get_charge_current(dev, &val->const_charge_current_ua);
+	default:
+		return -ENOTSUP;
+	}
+}
+
+static int bq25180_set_prop(const struct device *dev, charger_prop_t prop,
+			    const union charger_propval *val)
+{
+	switch (prop) {
+	case CHARGER_PROP_CONSTANT_CHARGE_CURRENT_UA:
+		return bq25180_set_charge_current(dev, val->const_charge_current_ua);
+	default:
+		return -ENOTSUP;
+	}
+}
+
+static const struct charger_driver_api bq25180_api = {
+	.get_property = bq25180_get_prop,
+	.set_property = bq25180_set_prop,
+	.charge_enable = bq25183_charge_enable,
+};
+
+static int bq25180_init(const struct device *dev)
+{
+	const struct bq25180_config *cfg = dev->config;
+	uint8_t val;
+	int ret;
+
+	ret = i2c_reg_read_byte_dt(&cfg->i2c, BQ25180_MASK_ID, &val);
+	if (ret < 0) {
+		return ret;
+	}
+
+	val &= BQ25180_DEVICE_ID_MSK;
+	if (val != BQ25180_DEVICE_ID) {
+		LOG_ERR("Invalid device id: %02x", val);
+		return -EINVAL;
+	}
+
+	/* Disable the watchdog */
+	ret = i2c_reg_update_byte_dt(&cfg->i2c, BQ25180_IC_CTRL,
+				     BQ25180_WATCHDOG_SEL_1_MSK,
+				     BQ25180_WATCHDOG_DISABLE);
+	if (ret < 0) {
+		return ret;
+	}
+
+	if (cfg->initial_current_microamp > 0) {
+		ret = bq25180_ma_to_ichg(cfg->initial_current_microamp / 1000, &val);
+		if (ret < 0) {
+			return ret;
+		}
+
+		ret = i2c_reg_update_byte_dt(&cfg->i2c, BQ25180_ICHG_CTRL,
+					     BQ25180_ICHG_MSK, val);
+		if (ret < 0) {
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+#define CHARGER_BQ25180_INIT(inst)								\
+	static const struct bq25180_config bq25180_config_##inst = {				\
+		.i2c = I2C_DT_SPEC_INST_GET(inst),						\
+		.initial_current_microamp = DT_INST_PROP(					\
+				inst, constant_charge_current_max_microamp),			\
+	};											\
+												\
+	DEVICE_DT_INST_DEFINE(inst, bq25180_init, NULL, NULL,					\
+			      &bq25180_config_##inst, POST_KERNEL,				\
+			      CONFIG_CHARGER_INIT_PRIORITY,					\
+			      &bq25180_api);
+
+DT_INST_FOREACH_STATUS_OKAY(CHARGER_BQ25180_INIT)

dts/bindings/charger/ti,bq25180.yaml

@@ -0,0 +1,30 @@
+# Copyright 2024 Google LLC
+# SPDX-License-Identifier: Apache-2.0
+
+description: |
+  BQ25180 I2C Controlled, 1-Cell, 1-A Linear Battery Charger with Power Path
+  and Ship Mode.
+
+  The device has a single child node for the charger. For example:
+
+  bq25180@6a {
+    compatible = "ti,bq25180";
+    reg = <0x6a>;
+
+    constant-charge-current-max-microamp = <500000>;
+  };
+
+compatible: "ti,bq25180"
+
+include: [battery.yaml, i2c-device.yaml]
+
+
+properties:
+  constant-charge-current-max-microamp:
+    type: int
+    default: 0
+    description: |
+      Charge current set at init time in uA, available range is 5 mA to 800 mA.
+      The value specified will be rounded down to the closest implemented
+      value. If set to 0 (default) skip setting the charge current value at
+      driver initialization.

tests/drivers/build_all/charger/i2c.dtsi

@@ -28,3 +28,9 @@ max20335@1 {
 		constant-charge-voltage-max-microvolt = <4050000>;
 	};
 };
+
+bq25180@2 {
+	compatible = "ti,bq25180";
+	reg = <0x2>;
+	constant-charge-current-max-microamp = <500000>;
+};