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-rw-r--r--drivers/iio/chemical/vz89x.c412
1 files changed, 412 insertions, 0 deletions
diff --git a/drivers/iio/chemical/vz89x.c b/drivers/iio/chemical/vz89x.c
new file mode 100644
index 000000000..e7e1c74a3
--- /dev/null
+++ b/drivers/iio/chemical/vz89x.c
@@ -0,0 +1,412 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * vz89x.c - Support for SGX Sensortech MiCS VZ89X VOC sensors
+ *
+ * Copyright (C) 2015-2018
+ * Author: Matt Ranostay <matt.ranostay@konsulko.com>
+ */
+
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/mod_devicetable.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define VZ89X_REG_MEASUREMENT 0x09
+#define VZ89X_REG_MEASUREMENT_RD_SIZE 6
+#define VZ89X_REG_MEASUREMENT_WR_SIZE 3
+
+#define VZ89X_VOC_CO2_IDX 0
+#define VZ89X_VOC_SHORT_IDX 1
+#define VZ89X_VOC_TVOC_IDX 2
+#define VZ89X_VOC_RESISTANCE_IDX 3
+
+#define VZ89TE_REG_MEASUREMENT 0x0c
+#define VZ89TE_REG_MEASUREMENT_RD_SIZE 7
+#define VZ89TE_REG_MEASUREMENT_WR_SIZE 6
+
+#define VZ89TE_VOC_TVOC_IDX 0
+#define VZ89TE_VOC_CO2_IDX 1
+#define VZ89TE_VOC_RESISTANCE_IDX 2
+
+enum {
+ VZ89X,
+ VZ89TE,
+};
+
+struct vz89x_chip_data;
+
+struct vz89x_data {
+ struct i2c_client *client;
+ const struct vz89x_chip_data *chip;
+ struct mutex lock;
+ int (*xfer)(struct vz89x_data *data, u8 cmd);
+
+ bool is_valid;
+ unsigned long last_update;
+ u8 buffer[VZ89TE_REG_MEASUREMENT_RD_SIZE];
+};
+
+struct vz89x_chip_data {
+ bool (*valid)(struct vz89x_data *data);
+ const struct iio_chan_spec *channels;
+ u8 num_channels;
+
+ u8 cmd;
+ u8 read_size;
+ u8 write_size;
+};
+
+static const struct iio_chan_spec vz89x_channels[] = {
+ {
+ .type = IIO_CONCENTRATION,
+ .channel2 = IIO_MOD_CO2,
+ .modified = 1,
+ .info_mask_separate =
+ BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_RAW),
+ .address = VZ89X_VOC_CO2_IDX,
+ },
+ {
+ .type = IIO_CONCENTRATION,
+ .channel2 = IIO_MOD_VOC,
+ .modified = 1,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ .address = VZ89X_VOC_SHORT_IDX,
+ .extend_name = "short",
+ },
+ {
+ .type = IIO_CONCENTRATION,
+ .channel2 = IIO_MOD_VOC,
+ .modified = 1,
+ .info_mask_separate =
+ BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_RAW),
+ .address = VZ89X_VOC_TVOC_IDX,
+ },
+ {
+ .type = IIO_RESISTANCE,
+ .info_mask_separate =
+ BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+ .address = VZ89X_VOC_RESISTANCE_IDX,
+ .scan_index = -1,
+ .scan_type = {
+ .endianness = IIO_LE,
+ },
+ },
+};
+
+static const struct iio_chan_spec vz89te_channels[] = {
+ {
+ .type = IIO_CONCENTRATION,
+ .channel2 = IIO_MOD_VOC,
+ .modified = 1,
+ .info_mask_separate =
+ BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_RAW),
+ .address = VZ89TE_VOC_TVOC_IDX,
+ },
+
+ {
+ .type = IIO_CONCENTRATION,
+ .channel2 = IIO_MOD_CO2,
+ .modified = 1,
+ .info_mask_separate =
+ BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_RAW),
+ .address = VZ89TE_VOC_CO2_IDX,
+ },
+ {
+ .type = IIO_RESISTANCE,
+ .info_mask_separate =
+ BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+ .address = VZ89TE_VOC_RESISTANCE_IDX,
+ .scan_index = -1,
+ .scan_type = {
+ .endianness = IIO_BE,
+ },
+ },
+};
+
+static IIO_CONST_ATTR(in_concentration_co2_scale, "0.00000698689");
+static IIO_CONST_ATTR(in_concentration_voc_scale, "0.00000000436681223");
+
+static struct attribute *vz89x_attributes[] = {
+ &iio_const_attr_in_concentration_co2_scale.dev_attr.attr,
+ &iio_const_attr_in_concentration_voc_scale.dev_attr.attr,
+ NULL,
+};
+
+static const struct attribute_group vz89x_attrs_group = {
+ .attrs = vz89x_attributes,
+};
+
+/*
+ * Chipset sometime updates in the middle of a reading causing it to reset the
+ * data pointer, and causing invalid reading of previous data.
+ * We can check for this by reading MSB of the resistance reading that is
+ * always zero, and by also confirming the VOC_short isn't zero.
+ */
+
+static bool vz89x_measurement_is_valid(struct vz89x_data *data)
+{
+ if (data->buffer[VZ89X_VOC_SHORT_IDX] == 0)
+ return true;
+
+ return !!(data->buffer[data->chip->read_size - 1] > 0);
+}
+
+/* VZ89TE device has a modified CRC-8 two complement check */
+static bool vz89te_measurement_is_valid(struct vz89x_data *data)
+{
+ u8 crc = 0;
+ int i, sum = 0;
+
+ for (i = 0; i < (data->chip->read_size - 1); i++) {
+ sum = crc + data->buffer[i];
+ crc = sum;
+ crc += sum / 256;
+ }
+
+ return !((0xff - crc) == data->buffer[data->chip->read_size - 1]);
+}
+
+static int vz89x_i2c_xfer(struct vz89x_data *data, u8 cmd)
+{
+ const struct vz89x_chip_data *chip = data->chip;
+ struct i2c_client *client = data->client;
+ struct i2c_msg msg[2];
+ int ret;
+ u8 buf[6] = { cmd, 0, 0, 0, 0, 0xf3 };
+
+ msg[0].addr = client->addr;
+ msg[0].flags = client->flags;
+ msg[0].len = chip->write_size;
+ msg[0].buf = (char *) &buf;
+
+ msg[1].addr = client->addr;
+ msg[1].flags = client->flags | I2C_M_RD;
+ msg[1].len = chip->read_size;
+ msg[1].buf = (char *) &data->buffer;
+
+ ret = i2c_transfer(client->adapter, msg, 2);
+
+ return (ret == 2) ? 0 : ret;
+}
+
+static int vz89x_smbus_xfer(struct vz89x_data *data, u8 cmd)
+{
+ struct i2c_client *client = data->client;
+ int ret;
+ int i;
+
+ ret = i2c_smbus_write_word_data(client, cmd, 0);
+ if (ret < 0)
+ return ret;
+
+ for (i = 0; i < data->chip->read_size; i++) {
+ ret = i2c_smbus_read_byte(client);
+ if (ret < 0)
+ return ret;
+ data->buffer[i] = ret;
+ }
+
+ return 0;
+}
+
+static int vz89x_get_measurement(struct vz89x_data *data)
+{
+ const struct vz89x_chip_data *chip = data->chip;
+ int ret;
+
+ /* sensor can only be polled once a second max per datasheet */
+ if (!time_after(jiffies, data->last_update + HZ))
+ return data->is_valid ? 0 : -EAGAIN;
+
+ data->is_valid = false;
+ data->last_update = jiffies;
+
+ ret = data->xfer(data, chip->cmd);
+ if (ret < 0)
+ return ret;
+
+ ret = chip->valid(data);
+ if (ret)
+ return -EAGAIN;
+
+ data->is_valid = true;
+
+ return 0;
+}
+
+static int vz89x_get_resistance_reading(struct vz89x_data *data,
+ struct iio_chan_spec const *chan,
+ int *val)
+{
+ u8 *tmp = &data->buffer[chan->address];
+
+ switch (chan->scan_type.endianness) {
+ case IIO_LE:
+ *val = le32_to_cpup((__le32 *) tmp) & GENMASK(23, 0);
+ break;
+ case IIO_BE:
+ *val = be32_to_cpup((__be32 *) tmp) >> 8;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int vz89x_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long mask)
+{
+ struct vz89x_data *data = iio_priv(indio_dev);
+ int ret = -EINVAL;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ mutex_lock(&data->lock);
+ ret = vz89x_get_measurement(data);
+ mutex_unlock(&data->lock);
+
+ if (ret)
+ return ret;
+
+ switch (chan->type) {
+ case IIO_CONCENTRATION:
+ *val = data->buffer[chan->address];
+ return IIO_VAL_INT;
+ case IIO_RESISTANCE:
+ ret = vz89x_get_resistance_reading(data, chan, val);
+ if (!ret)
+ return IIO_VAL_INT;
+ break;
+ default:
+ return -EINVAL;
+ }
+ break;
+ case IIO_CHAN_INFO_SCALE:
+ switch (chan->type) {
+ case IIO_RESISTANCE:
+ *val = 10;
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+ break;
+ case IIO_CHAN_INFO_OFFSET:
+ switch (chan->channel2) {
+ case IIO_MOD_CO2:
+ *val = 44;
+ *val2 = 250000;
+ return IIO_VAL_INT_PLUS_MICRO;
+ case IIO_MOD_VOC:
+ *val = -13;
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+ }
+
+ return ret;
+}
+
+static const struct iio_info vz89x_info = {
+ .attrs = &vz89x_attrs_group,
+ .read_raw = vz89x_read_raw,
+};
+
+static const struct vz89x_chip_data vz89x_chips[] = {
+ {
+ .valid = vz89x_measurement_is_valid,
+
+ .cmd = VZ89X_REG_MEASUREMENT,
+ .read_size = VZ89X_REG_MEASUREMENT_RD_SIZE,
+ .write_size = VZ89X_REG_MEASUREMENT_WR_SIZE,
+
+ .channels = vz89x_channels,
+ .num_channels = ARRAY_SIZE(vz89x_channels),
+ },
+ {
+ .valid = vz89te_measurement_is_valid,
+
+ .cmd = VZ89TE_REG_MEASUREMENT,
+ .read_size = VZ89TE_REG_MEASUREMENT_RD_SIZE,
+ .write_size = VZ89TE_REG_MEASUREMENT_WR_SIZE,
+
+ .channels = vz89te_channels,
+ .num_channels = ARRAY_SIZE(vz89te_channels),
+ },
+};
+
+static const struct of_device_id vz89x_dt_ids[] = {
+ { .compatible = "sgx,vz89x", .data = (void *) VZ89X },
+ { .compatible = "sgx,vz89te", .data = (void *) VZ89TE },
+ { }
+};
+MODULE_DEVICE_TABLE(of, vz89x_dt_ids);
+
+static int vz89x_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct device *dev = &client->dev;
+ struct iio_dev *indio_dev;
+ struct vz89x_data *data;
+ int chip_id;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+ if (!indio_dev)
+ return -ENOMEM;
+ data = iio_priv(indio_dev);
+
+ if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+ data->xfer = vz89x_i2c_xfer;
+ else if (i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BYTE))
+ data->xfer = vz89x_smbus_xfer;
+ else
+ return -EOPNOTSUPP;
+
+ if (!dev_fwnode(dev))
+ chip_id = id->driver_data;
+ else
+ chip_id = (unsigned long)device_get_match_data(dev);
+
+ i2c_set_clientdata(client, indio_dev);
+ data->client = client;
+ data->chip = &vz89x_chips[chip_id];
+ data->last_update = jiffies - HZ;
+ mutex_init(&data->lock);
+
+ indio_dev->info = &vz89x_info;
+ indio_dev->name = dev_name(dev);
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ indio_dev->channels = data->chip->channels;
+ indio_dev->num_channels = data->chip->num_channels;
+
+ return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct i2c_device_id vz89x_id[] = {
+ { "vz89x", VZ89X },
+ { "vz89te", VZ89TE },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, vz89x_id);
+
+static struct i2c_driver vz89x_driver = {
+ .driver = {
+ .name = "vz89x",
+ .of_match_table = vz89x_dt_ids,
+ },
+ .probe = vz89x_probe,
+ .id_table = vz89x_id,
+};
+module_i2c_driver(vz89x_driver);
+
+MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
+MODULE_DESCRIPTION("SGX Sensortech MiCS VZ89X VOC sensors");
+MODULE_LICENSE("GPL v2");