From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- drivers/iio/chemical/ccs811.c | 578 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 578 insertions(+) create mode 100644 drivers/iio/chemical/ccs811.c (limited to 'drivers/iio/chemical/ccs811.c') diff --git a/drivers/iio/chemical/ccs811.c b/drivers/iio/chemical/ccs811.c new file mode 100644 index 0000000000..87741f155c --- /dev/null +++ b/drivers/iio/chemical/ccs811.c @@ -0,0 +1,578 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ccs811.c - Support for AMS CCS811 VOC Sensor + * + * Copyright (C) 2017 Narcisa Vasile + * + * Datasheet: ams.com/content/download/951091/2269479/CCS811_DS000459_3-00.pdf + * + * IIO driver for AMS CCS811 (I2C address 0x5A/0x5B set by ADDR Low/High) + * + * TODO: + * 1. Make the drive mode selectable form userspace + * 2. Add support for interrupts + * 3. Adjust time to wait for data to be ready based on selected operation mode + * 4. Read error register and put the information in logs + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define CCS811_STATUS 0x00 +#define CCS811_MEAS_MODE 0x01 +#define CCS811_ALG_RESULT_DATA 0x02 +#define CCS811_RAW_DATA 0x03 +#define CCS811_HW_ID 0x20 +#define CCS811_HW_ID_VALUE 0x81 +#define CCS811_HW_VERSION 0x21 +#define CCS811_HW_VERSION_VALUE 0x10 +#define CCS811_HW_VERSION_MASK 0xF0 +#define CCS811_ERR 0xE0 +/* Used to transition from boot to application mode */ +#define CCS811_APP_START 0xF4 +#define CCS811_SW_RESET 0xFF + +/* Status register flags */ +#define CCS811_STATUS_ERROR BIT(0) +#define CCS811_STATUS_DATA_READY BIT(3) +#define CCS811_STATUS_APP_VALID_MASK BIT(4) +#define CCS811_STATUS_APP_VALID_LOADED BIT(4) +/* + * Value of FW_MODE bit of STATUS register describes the sensor's state: + * 0: Firmware is in boot mode, this allows new firmware to be loaded + * 1: Firmware is in application mode. CCS811 is ready to take ADC measurements + */ +#define CCS811_STATUS_FW_MODE_MASK BIT(7) +#define CCS811_STATUS_FW_MODE_APPLICATION BIT(7) + +/* Measurement modes */ +#define CCS811_MODE_IDLE 0x00 +#define CCS811_MODE_IAQ_1SEC 0x10 +#define CCS811_MODE_IAQ_10SEC 0x20 +#define CCS811_MODE_IAQ_60SEC 0x30 +#define CCS811_MODE_RAW_DATA 0x40 + +#define CCS811_MEAS_MODE_INTERRUPT BIT(3) + +#define CCS811_VOLTAGE_MASK 0x3FF + +struct ccs811_reading { + __be16 co2; + __be16 voc; + u8 status; + u8 error; + __be16 raw_data; +} __attribute__((__packed__)); + +struct ccs811_data { + struct i2c_client *client; + struct mutex lock; /* Protect readings */ + struct ccs811_reading buffer; + struct iio_trigger *drdy_trig; + struct gpio_desc *wakeup_gpio; + bool drdy_trig_on; + /* Ensures correct alignment of timestamp if present */ + struct { + s16 channels[2]; + s64 ts __aligned(8); + } scan; +}; + +static const struct iio_chan_spec ccs811_channels[] = { + { + .type = IIO_CURRENT, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + .scan_index = -1, + }, { + .type = IIO_VOLTAGE, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + .scan_index = -1, + }, { + .type = IIO_CONCENTRATION, + .channel2 = IIO_MOD_CO2, + .modified = 1, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + .scan_index = 0, + .scan_type = { + .sign = 'u', + .realbits = 16, + .storagebits = 16, + .endianness = IIO_BE, + }, + }, { + .type = IIO_CONCENTRATION, + .channel2 = IIO_MOD_VOC, + .modified = 1, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + .scan_index = 1, + .scan_type = { + .sign = 'u', + .realbits = 16, + .storagebits = 16, + .endianness = IIO_BE, + }, + }, + IIO_CHAN_SOFT_TIMESTAMP(2), +}; + +/* + * The CCS811 powers-up in boot mode. A setup write to CCS811_APP_START will + * transition the sensor to application mode. + */ +static int ccs811_start_sensor_application(struct i2c_client *client) +{ + int ret; + + ret = i2c_smbus_read_byte_data(client, CCS811_STATUS); + if (ret < 0) + return ret; + + if ((ret & CCS811_STATUS_FW_MODE_APPLICATION)) + return 0; + + if ((ret & CCS811_STATUS_APP_VALID_MASK) != + CCS811_STATUS_APP_VALID_LOADED) + return -EIO; + + ret = i2c_smbus_write_byte(client, CCS811_APP_START); + if (ret < 0) + return ret; + + ret = i2c_smbus_read_byte_data(client, CCS811_STATUS); + if (ret < 0) + return ret; + + if ((ret & CCS811_STATUS_FW_MODE_MASK) != + CCS811_STATUS_FW_MODE_APPLICATION) { + dev_err(&client->dev, "Application failed to start. Sensor is still in boot mode.\n"); + return -EIO; + } + + return 0; +} + +static int ccs811_setup(struct i2c_client *client) +{ + int ret; + + ret = ccs811_start_sensor_application(client); + if (ret < 0) + return ret; + + return i2c_smbus_write_byte_data(client, CCS811_MEAS_MODE, + CCS811_MODE_IAQ_1SEC); +} + +static void ccs811_set_wakeup(struct ccs811_data *data, bool enable) +{ + if (!data->wakeup_gpio) + return; + + gpiod_set_value(data->wakeup_gpio, enable); + + if (enable) + usleep_range(50, 60); + else + usleep_range(20, 30); +} + +static int ccs811_get_measurement(struct ccs811_data *data) +{ + int ret, tries = 11; + + ccs811_set_wakeup(data, true); + + /* Maximum waiting time: 1s, as measurements are made every second */ + while (tries-- > 0) { + ret = i2c_smbus_read_byte_data(data->client, CCS811_STATUS); + if (ret < 0) + return ret; + + if ((ret & CCS811_STATUS_DATA_READY) || tries == 0) + break; + msleep(100); + } + if (!(ret & CCS811_STATUS_DATA_READY)) + return -EIO; + + ret = i2c_smbus_read_i2c_block_data(data->client, + CCS811_ALG_RESULT_DATA, 8, + (char *)&data->buffer); + ccs811_set_wakeup(data, false); + + return ret; +} + +static int ccs811_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct ccs811_data *data = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = iio_device_claim_direct_mode(indio_dev); + if (ret) + return ret; + mutex_lock(&data->lock); + ret = ccs811_get_measurement(data); + if (ret < 0) { + mutex_unlock(&data->lock); + iio_device_release_direct_mode(indio_dev); + return ret; + } + + switch (chan->type) { + case IIO_VOLTAGE: + *val = be16_to_cpu(data->buffer.raw_data) & + CCS811_VOLTAGE_MASK; + ret = IIO_VAL_INT; + break; + case IIO_CURRENT: + *val = be16_to_cpu(data->buffer.raw_data) >> 10; + ret = IIO_VAL_INT; + break; + case IIO_CONCENTRATION: + switch (chan->channel2) { + case IIO_MOD_CO2: + *val = be16_to_cpu(data->buffer.co2); + ret = IIO_VAL_INT; + break; + case IIO_MOD_VOC: + *val = be16_to_cpu(data->buffer.voc); + ret = IIO_VAL_INT; + break; + default: + ret = -EINVAL; + } + break; + default: + ret = -EINVAL; + } + mutex_unlock(&data->lock); + iio_device_release_direct_mode(indio_dev); + + return ret; + + case IIO_CHAN_INFO_SCALE: + switch (chan->type) { + case IIO_VOLTAGE: + *val = 1; + *val2 = 612903; + return IIO_VAL_INT_PLUS_MICRO; + case IIO_CURRENT: + *val = 0; + *val2 = 1000; + return IIO_VAL_INT_PLUS_MICRO; + case IIO_CONCENTRATION: + switch (chan->channel2) { + case IIO_MOD_CO2: + *val = 0; + *val2 = 100; + return IIO_VAL_INT_PLUS_MICRO; + case IIO_MOD_VOC: + *val = 0; + *val2 = 100; + return IIO_VAL_INT_PLUS_NANO; + default: + return -EINVAL; + } + default: + return -EINVAL; + } + default: + return -EINVAL; + } +} + +static const struct iio_info ccs811_info = { + .read_raw = ccs811_read_raw, +}; + +static int ccs811_set_trigger_state(struct iio_trigger *trig, + bool state) +{ + struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); + struct ccs811_data *data = iio_priv(indio_dev); + int ret; + + ret = i2c_smbus_read_byte_data(data->client, CCS811_MEAS_MODE); + if (ret < 0) + return ret; + + if (state) + ret |= CCS811_MEAS_MODE_INTERRUPT; + else + ret &= ~CCS811_MEAS_MODE_INTERRUPT; + + data->drdy_trig_on = state; + + return i2c_smbus_write_byte_data(data->client, CCS811_MEAS_MODE, ret); +} + +static const struct iio_trigger_ops ccs811_trigger_ops = { + .set_trigger_state = ccs811_set_trigger_state, +}; + +static irqreturn_t ccs811_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + struct ccs811_data *data = iio_priv(indio_dev); + struct i2c_client *client = data->client; + int ret; + + ret = i2c_smbus_read_i2c_block_data(client, CCS811_ALG_RESULT_DATA, + sizeof(data->scan.channels), + (u8 *)data->scan.channels); + if (ret != 4) { + dev_err(&client->dev, "cannot read sensor data\n"); + goto err; + } + + iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, + iio_get_time_ns(indio_dev)); + +err: + iio_trigger_notify_done(indio_dev->trig); + + return IRQ_HANDLED; +} + +static irqreturn_t ccs811_data_rdy_trigger_poll(int irq, void *private) +{ + struct iio_dev *indio_dev = private; + struct ccs811_data *data = iio_priv(indio_dev); + + if (data->drdy_trig_on) + iio_trigger_poll(data->drdy_trig); + + return IRQ_HANDLED; +} + +static int ccs811_reset(struct i2c_client *client) +{ + struct gpio_desc *reset_gpio; + int ret; + + reset_gpio = devm_gpiod_get_optional(&client->dev, "reset", + GPIOD_OUT_LOW); + if (IS_ERR(reset_gpio)) + return PTR_ERR(reset_gpio); + + /* Try to reset using nRESET pin if available else do SW reset */ + if (reset_gpio) { + gpiod_set_value(reset_gpio, 1); + usleep_range(20, 30); + gpiod_set_value(reset_gpio, 0); + } else { + /* + * As per the datasheet, this sequence of values needs to be + * written to the SW_RESET register for triggering the soft + * reset in the device and placing it in boot mode. + */ + static const u8 reset_seq[] = { + 0x11, 0xE5, 0x72, 0x8A, + }; + + ret = i2c_smbus_write_i2c_block_data(client, CCS811_SW_RESET, + sizeof(reset_seq), reset_seq); + if (ret < 0) { + dev_err(&client->dev, "Failed to reset sensor\n"); + return ret; + } + } + + /* tSTART delay required after reset */ + usleep_range(1000, 2000); + + return 0; +} + +static int ccs811_probe(struct i2c_client *client) +{ + const struct i2c_device_id *id = i2c_client_get_device_id(client); + struct iio_dev *indio_dev; + struct ccs811_data *data; + int ret; + + if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE + | I2C_FUNC_SMBUS_BYTE_DATA + | I2C_FUNC_SMBUS_READ_I2C_BLOCK)) + return -EOPNOTSUPP; + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); + if (!indio_dev) + return -ENOMEM; + + data = iio_priv(indio_dev); + i2c_set_clientdata(client, indio_dev); + data->client = client; + + data->wakeup_gpio = devm_gpiod_get_optional(&client->dev, "wakeup", + GPIOD_OUT_HIGH); + if (IS_ERR(data->wakeup_gpio)) + return PTR_ERR(data->wakeup_gpio); + + ccs811_set_wakeup(data, true); + + ret = ccs811_reset(client); + if (ret) { + ccs811_set_wakeup(data, false); + return ret; + } + + /* Check hardware id (should be 0x81 for this family of devices) */ + ret = i2c_smbus_read_byte_data(client, CCS811_HW_ID); + if (ret < 0) { + ccs811_set_wakeup(data, false); + return ret; + } + + if (ret != CCS811_HW_ID_VALUE) { + dev_err(&client->dev, "hardware id doesn't match CCS81x\n"); + ccs811_set_wakeup(data, false); + return -ENODEV; + } + + ret = i2c_smbus_read_byte_data(client, CCS811_HW_VERSION); + if (ret < 0) { + ccs811_set_wakeup(data, false); + return ret; + } + + if ((ret & CCS811_HW_VERSION_MASK) != CCS811_HW_VERSION_VALUE) { + dev_err(&client->dev, "no CCS811 sensor\n"); + ccs811_set_wakeup(data, false); + return -ENODEV; + } + + ret = ccs811_setup(client); + if (ret < 0) { + ccs811_set_wakeup(data, false); + return ret; + } + + ccs811_set_wakeup(data, false); + + mutex_init(&data->lock); + + indio_dev->name = id->name; + indio_dev->info = &ccs811_info; + indio_dev->modes = INDIO_DIRECT_MODE; + + indio_dev->channels = ccs811_channels; + indio_dev->num_channels = ARRAY_SIZE(ccs811_channels); + + if (client->irq > 0) { + ret = devm_request_threaded_irq(&client->dev, client->irq, + ccs811_data_rdy_trigger_poll, + NULL, + IRQF_TRIGGER_FALLING | + IRQF_ONESHOT, + "ccs811_irq", indio_dev); + if (ret) { + dev_err(&client->dev, "irq request error %d\n", -ret); + goto err_poweroff; + } + + data->drdy_trig = devm_iio_trigger_alloc(&client->dev, + "%s-dev%d", + indio_dev->name, + iio_device_id(indio_dev)); + if (!data->drdy_trig) { + ret = -ENOMEM; + goto err_poweroff; + } + + data->drdy_trig->ops = &ccs811_trigger_ops; + iio_trigger_set_drvdata(data->drdy_trig, indio_dev); + ret = iio_trigger_register(data->drdy_trig); + if (ret) + goto err_poweroff; + + indio_dev->trig = iio_trigger_get(data->drdy_trig); + } + + ret = iio_triggered_buffer_setup(indio_dev, NULL, + ccs811_trigger_handler, NULL); + + if (ret < 0) { + dev_err(&client->dev, "triggered buffer setup failed\n"); + goto err_trigger_unregister; + } + + ret = iio_device_register(indio_dev); + if (ret < 0) { + dev_err(&client->dev, "unable to register iio device\n"); + goto err_buffer_cleanup; + } + return 0; + +err_buffer_cleanup: + iio_triggered_buffer_cleanup(indio_dev); +err_trigger_unregister: + if (data->drdy_trig) + iio_trigger_unregister(data->drdy_trig); +err_poweroff: + i2c_smbus_write_byte_data(client, CCS811_MEAS_MODE, CCS811_MODE_IDLE); + + return ret; +} + +static void ccs811_remove(struct i2c_client *client) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(client); + struct ccs811_data *data = iio_priv(indio_dev); + int ret; + + iio_device_unregister(indio_dev); + iio_triggered_buffer_cleanup(indio_dev); + if (data->drdy_trig) + iio_trigger_unregister(data->drdy_trig); + + ret = i2c_smbus_write_byte_data(client, CCS811_MEAS_MODE, + CCS811_MODE_IDLE); + if (ret) + dev_warn(&client->dev, "Failed to power down device (%pe)\n", + ERR_PTR(ret)); +} + +static const struct i2c_device_id ccs811_id[] = { + {"ccs811", 0}, + { } +}; +MODULE_DEVICE_TABLE(i2c, ccs811_id); + +static const struct of_device_id ccs811_dt_ids[] = { + { .compatible = "ams,ccs811" }, + { } +}; +MODULE_DEVICE_TABLE(of, ccs811_dt_ids); + +static struct i2c_driver ccs811_driver = { + .driver = { + .name = "ccs811", + .of_match_table = ccs811_dt_ids, + }, + .probe = ccs811_probe, + .remove = ccs811_remove, + .id_table = ccs811_id, +}; +module_i2c_driver(ccs811_driver); + +MODULE_AUTHOR("Narcisa Vasile "); +MODULE_DESCRIPTION("CCS811 volatile organic compounds sensor"); +MODULE_LICENSE("GPL v2"); -- cgit v1.2.3