| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Jose A. Perez de Azpillaga | 1339 | 100.00% | 1 | 100.00% |
| Total | 1339 | 1 |
// SPDX-License-Identifier: GPL-2.0+ /* * IIO driver for Broadcom APDS9999 Lux Light Sensor * * Copyright (C) 2026 * Author: Jose A. Perez de Azpillaga <azpijr@gmail.com> * * TODO: proximity sensor */ #include <linux/bitfield.h> #include <linux/bitops.h> #include <linux/cleanup.h> #include <linux/delay.h> #include <linux/i2c.h> #include <linux/iio/iio.h> #include <linux/iio/sysfs.h> #include <linux/math64.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/unaligned.h> #include <linux/units.h> #define APDS9999_REG_MAIN_CTRL 0x00 #define APDS9999_MAIN_CTRL_LS_EN BIT(1) #define APDS9999_REG_LS_MEAS_RATE 0x04 #define APDS9999_LS_RES_MASK GENMASK(6, 4) #define APDS9999_LS_RATE_MASK GENMASK(2, 0) #define APDS9999_REG_LS_GAIN 0x05 #define APDS9999_REG_PART_ID 0x06 #define APDS9999_REG_MAIN_STATUS 0x07 #define APDS9999_MAIN_STATUS_LS_DATA BIT(3) #define APDS9999_REG_LS_DATA_IR_0 0x0A #define APDS9999_REG_LS_DATA_GREEN_0 0x0D #define APDS9999_REG_LS_DATA_BLUE_0 0x10 #define APDS9999_REG_LS_DATA_RED_0 0x13 #define APDS9999_PART_ID 0xC2 #define APDS9999_GAIN_1X 0 #define APDS9999_GAIN_3X 1 #define APDS9999_GAIN_6X 2 #define APDS9999_GAIN_9X 3 #define APDS9999_GAIN_18X 4 static const int apds9999_gains[] = { [APDS9999_GAIN_1X] = 1, [APDS9999_GAIN_3X] = 3, [APDS9999_GAIN_6X] = 6, [APDS9999_GAIN_9X] = 9, [APDS9999_GAIN_18X] = 18, }; #define APDS9999_RES_20BIT 0 #define APDS9999_RES_19BIT 1 #define APDS9999_RES_18BIT 2 #define APDS9999_RES_17BIT 3 #define APDS9999_RES_16BIT 4 #define APDS9999_RES_13BIT 5 static const int apds9999_itimes_us[] = { [APDS9999_RES_20BIT] = 400 * USEC_PER_MSEC, [APDS9999_RES_19BIT] = 200 * USEC_PER_MSEC, [APDS9999_RES_18BIT] = 100 * USEC_PER_MSEC, [APDS9999_RES_17BIT] = 50 * USEC_PER_MSEC, [APDS9999_RES_16BIT] = 25 * USEC_PER_MSEC, [APDS9999_RES_13BIT] = 3125, }; #define APDS9999_RATE_25_MS 0 #define APDS9999_RATE_50_MS 1 #define APDS9999_RATE_100_MS 2 #define APDS9999_RATE_200_MS 3 #define APDS9999_RATE_500_MS 4 #define APDS9999_RATE_1000_MS 5 #define APDS9999_RATE_2000_MS 6 struct apds9999_data { struct i2c_client *client; /* lock: serializes access to device registers and cached values */ struct mutex lock; int als_gain_idx; int als_res; int als_rate; }; static void apds9999_standby(void *client) { i2c_smbus_write_byte_data(client, APDS9999_REG_MAIN_CTRL, 0); } /* * Apply power-on defaults: 18-bit / 100 ms resolution and rate, * 3x gain. These match the datasheet reset values. */ static int apds9999_init(struct apds9999_data *data) { struct device *dev = &data->client->dev; struct i2c_client *client = data->client; u8 regval; int ret; ret = devm_add_action_or_reset(dev, apds9999_standby, client); if (ret) return ret; guard(mutex)(&data->lock); regval = FIELD_PREP(APDS9999_LS_RES_MASK, APDS9999_RES_18BIT) | FIELD_PREP(APDS9999_LS_RATE_MASK, APDS9999_RATE_100_MS); ret = i2c_smbus_write_byte_data(client, APDS9999_REG_LS_MEAS_RATE, regval); if (ret) return ret; data->als_res = APDS9999_RES_18BIT; data->als_rate = APDS9999_RATE_100_MS; ret = i2c_smbus_write_byte_data(client, APDS9999_REG_LS_GAIN, APDS9999_GAIN_3X); if (ret) return ret; data->als_gain_idx = APDS9999_GAIN_3X; return i2c_smbus_write_byte_data(client, APDS9999_REG_MAIN_CTRL, APDS9999_MAIN_CTRL_LS_EN); } static int apds9999_read_channel(struct apds9999_data *data, u8 reg, u32 *counts) { struct i2c_client *client = data->client; u8 buf[3]; int ret, tries; guard(mutex)(&data->lock); /* * Poll MAIN_STATUS for new data. Timeout: ~2 integration periods * plus margin. Each try sleeps 20 ms. */ tries = max(2, (apds9999_itimes_us[data->als_res] * 2) / 20000); while (tries--) { ret = i2c_smbus_read_byte_data(client, APDS9999_REG_MAIN_STATUS); if (ret < 0) return ret; if (ret & APDS9999_MAIN_STATUS_LS_DATA) break; fsleep(20000); } if (tries < 0) return -ETIMEDOUT; ret = i2c_smbus_read_i2c_block_data(client, reg, sizeof(buf), buf); if (ret < 0) return ret; if (ret != sizeof(buf)) return -EIO; *counts = get_unaligned_le24(buf) & GENMASK(19, 0); return 0; } static int apds9999_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { struct apds9999_data *data = iio_priv(indio_dev); int gain, itime_us; u64 scale_nano; u32 counts; int ret; switch (mask) { case IIO_CHAN_INFO_RAW: ret = apds9999_read_channel(data, chan->address, &counts); if (ret) return ret; *val = (int)counts; return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: { u32 remainder; /* * Scale (lux per count) = 54 / (gain * integration_time_ms) * * The constant 54 is derived from the datasheet table: * at gain = 3x, itime = 100 ms -> 0.180 lux/count * -> C = 0.180 * 3 * 100 = 54 * * Expressed as IIO_VAL_INT_PLUS_NANO. */ gain = apds9999_gains[data->als_gain_idx]; itime_us = apds9999_itimes_us[data->als_res]; /* scale_nano = 54 * 1e12 / (gain * itime_us) nano-lux/count */ scale_nano = div_u64(54ULL * NSEC_PER_SEC * USEC_PER_MSEC, (u32)(gain * itime_us)); *val = (int)div_u64_rem(scale_nano, NSEC_PER_SEC, &remainder); *val2 = (int)remainder; return IIO_VAL_INT_PLUS_NANO; } case IIO_CHAN_INFO_INT_TIME: *val = 0; *val2 = apds9999_itimes_us[data->als_res]; return IIO_VAL_INT_PLUS_MICRO; default: return -EINVAL; } } static const struct iio_info apds9999_info = { .read_raw = apds9999_read_raw, }; /* * The green channel uses optical coating to approximate the human eye * spectral response. IIO_INTENSITY channels provide raw ADC data for * red, green, blue, and IR so userspace can compute weighted lux. */ static const struct iio_chan_spec apds9999_channels[] = { { .type = IIO_LIGHT, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME), .address = APDS9999_REG_LS_DATA_GREEN_0, }, { .type = IIO_INTENSITY, .modified = 1, .channel2 = IIO_MOD_LIGHT_RED, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME), .address = APDS9999_REG_LS_DATA_RED_0, }, { .type = IIO_INTENSITY, .modified = 1, .channel2 = IIO_MOD_LIGHT_GREEN, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME), .address = APDS9999_REG_LS_DATA_GREEN_0, }, { .type = IIO_INTENSITY, .modified = 1, .channel2 = IIO_MOD_LIGHT_BLUE, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME), .address = APDS9999_REG_LS_DATA_BLUE_0, }, { .type = IIO_INTENSITY, .modified = 1, .channel2 = IIO_MOD_LIGHT_IR, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME), .address = APDS9999_REG_LS_DATA_IR_0, }, }; static int apds9999_probe(struct i2c_client *client) { struct device *dev = &client->dev; struct apds9999_data *data; struct iio_dev *indio_dev; int ret, part_id; indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); if (!indio_dev) return -ENOMEM; data = iio_priv(indio_dev); data->client = client; ret = devm_mutex_init(dev, &data->lock); if (ret) return ret; part_id = i2c_smbus_read_byte_data(client, APDS9999_REG_PART_ID); if (part_id < 0) return dev_err_probe(dev, part_id, "failed to read PART_ID\n"); if (part_id != APDS9999_PART_ID) dev_info(dev, "unexpected PART_ID 0x%02x (expected 0x%02x)\n", part_id, APDS9999_PART_ID); ret = apds9999_init(data); if (ret) return dev_err_probe(dev, ret, "failed to initialize device\n"); indio_dev->name = "apds9999"; indio_dev->info = &apds9999_info; indio_dev->channels = apds9999_channels; indio_dev->num_channels = ARRAY_SIZE(apds9999_channels); indio_dev->modes = INDIO_DIRECT_MODE; ret = devm_iio_device_register(dev, indio_dev); if (ret) return dev_err_probe(dev, ret, "failed to register IIO device\n"); return 0; } static const struct i2c_device_id apds9999_id[] = { { .name = "apds9999" }, { } }; MODULE_DEVICE_TABLE(i2c, apds9999_id); static const struct of_device_id apds9999_of_match[] = { { .compatible = "brcm,apds9999" }, { } }; MODULE_DEVICE_TABLE(of, apds9999_of_match); static struct i2c_driver apds9999_driver = { .driver = { .name = "apds9999", .of_match_table = apds9999_of_match, }, .probe = apds9999_probe, .id_table = apds9999_id, }; module_i2c_driver(apds9999_driver); MODULE_AUTHOR("Jose A. Perez de Azpillaga <azpijr@gmail.com>"); MODULE_DESCRIPTION("APDS-9999 Lux Light Sensor IIO Driver"); MODULE_LICENSE("GPL");
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