| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Narcisa Ana Maria Vasile | 1839 | 81.37% | 4 | 40.00% |
| Manivannan Sadhasivam | 403 | 17.83% | 2 | 20.00% |
| Richard Lai | 16 | 0.71% | 3 | 30.00% |
| Thomas Gleixner | 2 | 0.09% | 1 | 10.00% |
| Total | 2260 | 10 |
// SPDX-License-Identifier: GPL-2.0-only /* * ccs811.c - Support for AMS CCS811 VOC Sensor * * Copyright (C) 2017 Narcisa Vasile <narcisaanamaria12@gmail.com> * * 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 <linux/delay.h> #include <linux/gpio/consumer.h> #include <linux/i2c.h> #include <linux/iio/iio.h> #include <linux/iio/buffer.h> #include <linux/iio/trigger.h> #include <linux/iio/triggered_buffer.h> #include <linux/iio/trigger_consumer.h> #include <linux/module.h> #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; }; 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; s16 buf[8]; /* s16 eCO2 + s16 TVOC + padding + 8 byte timestamp */ int ret; ret = i2c_smbus_read_i2c_block_data(client, CCS811_ALG_RESULT_DATA, 4, (u8 *)&buf); if (ret != 4) { dev_err(&client->dev, "cannot read sensor data\n"); goto err; } iio_push_to_buffers_with_timestamp(indio_dev, buf, 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) { 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->dev.parent = &client->dev; 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, indio_dev->id); if (!data->drdy_trig) { ret = -ENOMEM; goto err_poweroff; } data->drdy_trig->dev.parent = &client->dev; data->drdy_trig->ops = &ccs811_trigger_ops; iio_trigger_set_drvdata(data->drdy_trig, indio_dev); indio_dev->trig = data->drdy_trig; iio_trigger_get(indio_dev->trig); ret = iio_trigger_register(data->drdy_trig); if (ret) goto err_poweroff; } 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 int ccs811_remove(struct i2c_client *client) { struct iio_dev *indio_dev = i2c_get_clientdata(client); struct ccs811_data *data = iio_priv(indio_dev); iio_device_unregister(indio_dev); iio_triggered_buffer_cleanup(indio_dev); if (data->drdy_trig) iio_trigger_unregister(data->drdy_trig); return i2c_smbus_write_byte_data(client, CCS811_MEAS_MODE, CCS811_MODE_IDLE); } 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 <narcisaanamaria12@gmail.com>"); MODULE_DESCRIPTION("CCS811 volatile organic compounds sensor"); MODULE_LICENSE("GPL v2");
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