From bcab78e41c47fc4edc19ad217d78ed2e8ee20c28 Mon Sep 17 00:00:00 2001 From: Borislav Kereziev Date: Tue, 13 May 2025 21:58:39 +0100 Subject: [PATCH] drivers: sensor: Add support for BH1730 ambient light sensor This commit adds support for BH1730 ambient light sensor. Signed-off-by: Borislav Kereziev --- drivers/sensor/rohm/CMakeLists.txt | 1 + drivers/sensor/rohm/Kconfig | 1 + drivers/sensor/rohm/bh1730/CMakeLists.txt | 5 + drivers/sensor/rohm/bh1730/Kconfig | 12 + drivers/sensor/rohm/bh1730/bh1730.c | 306 ++++++++++++++++++++++ dts/bindings/sensor/rohm,bh1730.yaml | 37 +++ tests/drivers/build_all/sensor/i2c.dtsi | 5 + 7 files changed, 367 insertions(+) create mode 100644 drivers/sensor/rohm/bh1730/CMakeLists.txt create mode 100644 drivers/sensor/rohm/bh1730/Kconfig create mode 100644 drivers/sensor/rohm/bh1730/bh1730.c create mode 100644 dts/bindings/sensor/rohm,bh1730.yaml diff --git a/drivers/sensor/rohm/CMakeLists.txt b/drivers/sensor/rohm/CMakeLists.txt index 629421e3272f..724ec378d0e9 100644 --- a/drivers/sensor/rohm/CMakeLists.txt +++ b/drivers/sensor/rohm/CMakeLists.txt @@ -3,5 +3,6 @@ # zephyr-keep-sorted-start add_subdirectory_ifdef(CONFIG_BD8LB600FS_DIAGNOSTICS bd8lb600fs) +add_subdirectory_ifdef(CONFIG_BH1730 bh1730) add_subdirectory_ifdef(CONFIG_BH1750 bh1750) # zephyr-keep-sorted-stop diff --git a/drivers/sensor/rohm/Kconfig b/drivers/sensor/rohm/Kconfig index c03de16d89e7..ed8256200d88 100644 --- a/drivers/sensor/rohm/Kconfig +++ b/drivers/sensor/rohm/Kconfig @@ -3,5 +3,6 @@ # zephyr-keep-sorted-start source "drivers/sensor/rohm/bd8lb600fs/Kconfig" +source "drivers/sensor/rohm/bh1730/Kconfig" source "drivers/sensor/rohm/bh1750/Kconfig" # zephyr-keep-sorted-stop diff --git a/drivers/sensor/rohm/bh1730/CMakeLists.txt b/drivers/sensor/rohm/bh1730/CMakeLists.txt new file mode 100644 index 000000000000..3a3f4b2c0137 --- /dev/null +++ b/drivers/sensor/rohm/bh1730/CMakeLists.txt @@ -0,0 +1,5 @@ +# SPDX-License-Identifier: Apache-2.0 + +zephyr_library() + +zephyr_library_sources(bh1730.c) diff --git a/drivers/sensor/rohm/bh1730/Kconfig b/drivers/sensor/rohm/bh1730/Kconfig new file mode 100644 index 000000000000..f00f3b349fe3 --- /dev/null +++ b/drivers/sensor/rohm/bh1730/Kconfig @@ -0,0 +1,12 @@ +# BH1730 ambient light sensor configuration options + +# Copyright (c) 2025, Borislav Kereziev +# SPDX-License-Identifier: Apache-2.0 + +config BH1730 + bool "BH1730 Ambient Light Sensor" + default y + depends on DT_HAS_ROHM_BH1730_ENABLED + select I2C + help + Enable driver for BH1730 ambient light sensor. diff --git a/drivers/sensor/rohm/bh1730/bh1730.c b/drivers/sensor/rohm/bh1730/bh1730.c new file mode 100644 index 000000000000..e0d673cd6d44 --- /dev/null +++ b/drivers/sensor/rohm/bh1730/bh1730.c @@ -0,0 +1,306 @@ +/* + * Copyright (c) 2025, Borislav Kereziev + * + * SPDX-License-Identifier: Apache-2.0 + */ + +#define DT_DRV_COMPAT rohm_bh1730 + +#include +#include +#include +#include + +LOG_MODULE_REGISTER(BH1730, CONFIG_SENSOR_LOG_LEVEL); + +#define BH1730_REG_CONTROL 0x00 +#define BH1730_REG_TIMING 0x01 +#define BH1730_REG_GAIN 0x07 +#define BH1730_REG_ID 0x12 +#define BH1730_REG_DATA0LOW 0x14 +#define BH1730_REG_DATA0HIGH 0x15 +#define BH1730_REG_DATA1LOW 0x16 +#define BH1730_REG_DATA1HIGH 0x17 + +#define BH1730_PART_ID 0x71 +#define BH1730_GAIN_DEFAULT 0x0 +#define BH1730_ITIME_DEFAULT 0xDA +#define BH1730_CONTROL_ADC_EN_POWER_ON_SINGLE_READING 0x0B +#define BH1730_CONTROL_ADC_EN_POWER_ON 0x03 +#define BH1730_CONTROL_ADC_DATA_UPDATED (1 << 4) +#define BH1730_TINT 2.8E-9 /* Internal clock period Tint */ + +#define BH1730_CMD 0x80 /* Command register CMD bit */ +#define BH1730_CMD_ADDR_MASK 0x1F + +/* Data definitions */ + +struct bh1730_data { + uint16_t data0; /* visible light */ + uint16_t data1; /* infrared light */ +}; + +struct bh1730_config { + struct i2c_dt_spec i2c; + uint8_t gain; + uint8_t itime; +}; + +/* Prototypes */ + +static int bh1730_reg_read_8(const struct device *dev, uint8_t reg, uint8_t *val); +static int bh1730_reg_write_8(const struct device *dev, uint8_t reg, uint8_t val); +static int bh1730_data_read(const struct device *dev, uint16_t *data0, uint16_t *data1); +static uint32_t bh1730_get_integration_time_ms(uint8_t itime_reg); +static uint8_t bh1730_get_gain(uint8_t gain_reg_val); +static uint32_t bh1730_calculate_lux(uint16_t data0, uint16_t data1, uint8_t itime_reg, + uint8_t gain_reg); +static int bh1730_sample_fetch(const struct device *dev, enum sensor_channel chan); +static int bh1730_sample_get(const struct device *dev, enum sensor_channel chan, + struct sensor_value *val); +static int bh1730_init(const struct device *dev); + +/* Functions */ + +static int bh1730_reg_read_8(const struct device *dev, uint8_t reg, uint8_t *val) +{ + const struct bh1730_config *cfg = dev->config; + uint8_t cmd = BH1730_CMD | (reg & BH1730_CMD_ADDR_MASK); + + return i2c_write_read_dt(&cfg->i2c, &cmd, sizeof(cmd), val, sizeof(*val)); +} + +static int bh1730_reg_write_8(const struct device *dev, uint8_t reg, uint8_t val) +{ + const struct bh1730_config *cfg = dev->config; + uint8_t cmd = BH1730_CMD | (reg & BH1730_CMD_ADDR_MASK); + uint8_t buf[2] = {cmd, val}; + + return i2c_write_dt(&cfg->i2c, buf, sizeof(buf)); +} + +static int bh1730_data_read(const struct device *dev, uint16_t *data0, uint16_t *data1) +{ + const struct bh1730_config *cfg = dev->config; + + /* Ensure data has been updated */ + uint8_t control_reg = 0x0; + int err = bh1730_reg_read_8(dev, BH1730_REG_CONTROL, &control_reg); + + if (err) { + LOG_ERR("Failed reading CONTROL register"); + return -EIO; + } + if ((control_reg & BH1730_CONTROL_ADC_DATA_UPDATED) == 0) { + LOG_ERR("Data not updated"); + return -ENODATA; + } + + /* Read data0 and data1 bytes */ + uint8_t buffer[4] = {0}; + uint8_t cmd = BH1730_CMD | BH1730_REG_DATA0LOW; + + err = i2c_write_read_dt(&cfg->i2c, &cmd, sizeof(cmd), &buffer, sizeof(buffer)); + if (err) { + return -EIO; + } + + /* Data is shifted LSB first from sensor - swap */ + *data0 = (buffer[1] << 8 | buffer[0]); + *data1 = (buffer[3] << 8 | buffer[2]); + + return 0; +} + +static inline uint32_t bh1730_get_integration_time_ms(uint8_t itime_reg) +{ + /* Convert register to integration time in ms */ + const uint32_t K_scaled = 2699200; /* 2.8e-6 * 964 * 1000 * 1e6 */ + uint32_t integration_time_ms; + + integration_time_ms = (K_scaled * (256 - itime_reg)) / 1000000; + + return integration_time_ms; +} + +static inline uint8_t bh1730_get_gain(uint8_t gain_reg_val) +{ + /* Convert register value to gain */ + if (gain_reg_val == 0x0) { + return 1; + } + if (gain_reg_val == 0x01) { + return 2; + } + if (gain_reg_val == 0x02) { + return 64; + } + if (gain_reg_val == 0x03) { + return 128; + } + + return 1; +} + +static uint32_t bh1730_calculate_lux(uint16_t data0, uint16_t data1, uint8_t itime_reg, + uint8_t gain_reg) +{ + /* Check page 13 of datasheet for lux calculation formula */ + const uint32_t SCALE = 1000; + const uint32_t scale1026 = 102600; /* 102.6 * 1000 */ + + /* prevent division by zero */ + if (data0 == 0) { + return 0; + } + + uint32_t itime_ms = bh1730_get_integration_time_ms(itime_reg); + uint8_t gain = bh1730_get_gain(gain_reg); + + /* Compute ratio = (DATA1 / DATA0) scaled by 1000 */ + uint32_t ratio = ((uint32_t)data1 * SCALE) / data0; + uint32_t k0_scaled, k1_scaled; + + if (ratio < 260) { + k0_scaled = 1290; + k1_scaled = 2733; + } else if (ratio < 550) { + k0_scaled = 795; + k1_scaled = 859; + } else if (ratio < 1090) { + k0_scaled = 510; + k1_scaled = 345; + } else if (ratio < 2130) { + k0_scaled = 276; + k1_scaled = 130; + } else { + return 0; + } + + /* Compute numerator (scaled values, may be negative → use int64_t) */ + int64_t numerator = (int64_t)data0 * k0_scaled - (int64_t)data1 * k1_scaled; + uint64_t denominator = (uint64_t)gain * scale1026; + + if (numerator <= 0 || denominator == 0) { + return 0; + } + + uint32_t lux = (uint32_t)((numerator * itime_ms) / denominator); + + return lux; +} + +static int bh1730_sample_fetch(const struct device *dev, enum sensor_channel chan) +{ + struct bh1730_data *data = dev->data; + const struct bh1730_config *cfg = dev->config; + + if ((chan != SENSOR_CHAN_ALL) && (chan != SENSOR_CHAN_LIGHT)) { + LOG_ERR("Unsupported channel %d", chan); + return -ENOTSUP; + } + + /* Trigger measurement */ + int ret = bh1730_reg_write_8(dev, BH1730_REG_CONTROL, + BH1730_CONTROL_ADC_EN_POWER_ON_SINGLE_READING); + if (ret) { + LOG_ERR("Failed writing to CONTROL register"); + return -EIO; + } + + /* Wait for conversion */ + int32_t sleep_period_ms = bh1730_get_integration_time_ms(cfg->itime); + + k_msleep(sleep_period_ms); + + /* Read conversion result from device */ + ret = bh1730_data_read(dev, &data->data0, &data->data1); + if (ret) { + LOG_ERR("Failed reading data from sensor"); + return -EIO; + } + + return 0; +} + +static int bh1730_sample_get(const struct device *dev, enum sensor_channel chan, + struct sensor_value *val) +{ + struct bh1730_data *data = dev->data; + const struct bh1730_config *cfg = dev->config; + + if (chan != SENSOR_CHAN_ALL && chan != SENSOR_CHAN_LIGHT) { + return -ENOTSUP; + } + + uint32_t lux = bh1730_calculate_lux(data->data0, data->data1, cfg->itime, cfg->gain); + + val->val1 = lux; + val->val2 = 0; + + return 0; +} + +static int bh1730_init(const struct device *dev) +{ + const struct bh1730_config *cfg = dev->config; + int ret = 0; + + LOG_DBG("Initializing"); + + if (!i2c_is_ready_dt(&cfg->i2c)) { + LOG_ERR("I2C device not ready"); + return -ENODEV; + } + + /* Ensure BH1730 has valid ID */ + uint8_t val = 0; + + ret = bh1730_reg_read_8(dev, BH1730_REG_ID, &val); + if (ret != 0) { + LOG_ERR("Failed reading ID reg"); + return -ENODEV; + } + + /* Part number in bits 7:4 */ + if ((val >> 4) != (BH1730_PART_ID >> 4)) { + LOG_ERR("Part number does not match, received 0x%1X", val >> 4); + return -ENODEV; + } + + /* Configure part with gain */ + if (cfg->gain != BH1730_GAIN_DEFAULT) { + ret = bh1730_reg_write_8(dev, BH1730_REG_GAIN, cfg->gain); + if (ret) { + LOG_ERR("Failed writing to gain register"); + return -EIO; + } + } + + /* Configure part with itime */ + if (cfg->itime != BH1730_ITIME_DEFAULT) { + ret = bh1730_reg_write_8(dev, BH1730_REG_TIMING, cfg->itime); + if (ret) { + LOG_ERR("Failed writing to ITIME register"); + return -EIO; + } + } + + return ret; +} + +static DEVICE_API(sensor, bh1730_api) = {.sample_fetch = bh1730_sample_fetch, + .channel_get = bh1730_sample_get}; + +#define BH1730_DEFINE(inst) \ + static struct bh1730_data bh1730_data_##inst; \ + static const struct bh1730_config bh1730_config_##inst = { \ + .i2c = I2C_DT_SPEC_INST_GET(inst), \ + .gain = DT_INST_PROP(inst, gain), \ + .itime = DT_INST_PROP(inst, itime), \ + }; \ + SENSOR_DEVICE_DT_INST_DEFINE(inst, bh1730_init, NULL, &bh1730_data_##inst, \ + &bh1730_config_##inst, POST_KERNEL, \ + CONFIG_SENSOR_INIT_PRIORITY, &bh1730_api); + +DT_INST_FOREACH_STATUS_OKAY(BH1730_DEFINE) diff --git a/dts/bindings/sensor/rohm,bh1730.yaml b/dts/bindings/sensor/rohm,bh1730.yaml new file mode 100644 index 000000000000..0bd36c54ed43 --- /dev/null +++ b/dts/bindings/sensor/rohm,bh1730.yaml @@ -0,0 +1,37 @@ +# Copyright (c) 2025, Borislav Kereziev +# SPDX-License-Identifier: Apache-2.0 + +description: Rohm BH1730 ambient light sensor. + +compatible: "rohm,bh1730" + +include: [sensor-device.yaml, i2c-device.yaml] + +properties: + gain: + type: int + default: 0 + description: | + ADC resolution setting + 0 = x1 gain mode + 1 = x2 gain mode + 2 = x64 gain mode + 3 = x128 gain mode + Lower gain values (x1 and x2) reduce sensitivity and prevent + saturation in brighter environments. + Higher gain values (x64 and x128) result in higher sensitivity, + which are useful in low-light environments. + The default corresponds to the reset value of the GAIN register. + enum: + - 0 + - 1 + - 2 + - 3 + itime: + type: int + default: 0xDA + description: | + ITIME value in TIMING register determines integration time. + Higher values result in longer integration time and + increased accuracy. + The default corresponds to the reset value of the TIMING register. diff --git a/tests/drivers/build_all/sensor/i2c.dtsi b/tests/drivers/build_all/sensor/i2c.dtsi index b3e46bd853c2..b31c6d65bd59 100644 --- a/tests/drivers/build_all/sensor/i2c.dtsi +++ b/tests/drivers/build_all/sensor/i2c.dtsi @@ -1302,3 +1302,8 @@ test_i2c_rm3100: rm3100@b2 { reg = <0xb2>; int-gpios = <&test_gpio 0 0>; }; + +test_i2c_bh1730: bh1730@b3 { + compatible = "rohm,bh1730"; + reg = <0xb3>; +};