> Add support the VZ89TE variant which removes the voc_short channel,
> and has CRC check for data transactions.
comments below
> Signed-off-by: Matt Ranostay <mranostay@xxxxxxxxx>
> ---
> drivers/iio/chemical/vz89x.c | 149 +++++++++++++++++++++++++++++++++++--------
> 1 file changed, 123 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/iio/chemical/vz89x.c b/drivers/iio/chemical/vz89x.c
> index f498228e044d..0347761ebdba 100644
> --- a/drivers/iio/chemical/vz89x.c
> +++ b/drivers/iio/chemical/vz89x.c
> @@ -19,20 +19,33 @@
> #include <linux/mutex.h>
> #include <linux/init.h>
> #include <linux/i2c.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
>
> #include <linux/iio/iio.h>
> #include <linux/iio/sysfs.h>
>
> #define VZ89X_REG_MEASUREMENT 0x09
> +#define VZ89TE_REG_MEASUREMENT 0x0c
> +
> +#define VZ89X_REG_WRITE_SIZE 3
> +#define VZ89TE_REG_WRITE_SIZE 6
> +
> #define VZ89X_REG_MEASUREMENT_SIZE 6
> +#define VZ89TE_REG_MEASUREMENT_SIZE 7
>
> #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_VOC_TVOC_IDX 0
> +#define VZ89TE_VOC_CO2_IDX 1
> +#define VZ89TE_VOC_RESISTANCE_IDX 2
> +
> enum {
> VZ89X,
> + VZ89TE,
> };
>
> struct vz89x_data {
> @@ -79,6 +92,40 @@ static const struct iio_chan_spec vz89x_channels[] = {
> .info_mask_separate =
> BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
> .address = VZ89X_VOC_RESISTANCE_IDX,
> + .scan_index = -1,
> + .scan_type = {
scan_type with a scan_index of -1 is unexpected
> + .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,
> + },
> },
> };
>
> @@ -110,12 +157,27 @@ static int vz89x_measurement_is_valid(struct vz89x_data *data)
> return !!(data->buffer[data->read_size - 1] > 0);
> }
>
> +/* VZ89TE device has a modified CRC-8 two complement check */
> +static int vz89te_measurement_is_valid(struct vz89x_data *data)
return bool maybe?
> +{
> + u8 crc = 0;
> + int i, sum = 0;
> +
> + for (i = 0; i < (data->read_size - 1); i++) {
> + sum = crc + data->buffer[i];
> + crc = sum;
> + crc += sum / 256;
> + }
> +
> + return !((0xff - crc) == data->buffer[data->read_size - 1]);
> +}
> +
> static int vz89x_i2c_xfer(struct vz89x_data *data, u8 cmd)
> {
> struct i2c_client *client = data->client;
> struct i2c_msg msg[2];
> int ret;
> - u8 buf[3] = { cmd, 0, 0};
> + u8 buf[6] = { cmd, 0, 0, 0, 0, 0xf3};
>
> msg[0].addr = client->addr;
> msg[0].flags = client->flags;
> @@ -173,11 +235,24 @@ static int vz89x_get_measurement(struct vz89x_data *data)
> return 0;
> }
>
> -static int vz89x_get_resistance_reading(struct vz89x_data *data)
> +static int vz89x_get_resistance_reading(struct vz89x_data *data,
> + struct iio_chan_spec const *chan,
> + int *val)
> {
> - u8 *buf = &data->buffer[VZ89X_VOC_RESISTANCE_IDX];
> + u32 tmp = *((u32 *) ((u8 *) &data->buffer[chan->address]));
> +
> + switch (chan->scan_type.endianness) {
> + case IIO_LE:
> + *val = le32_to_cpu(tmp) & GENMASK(23, 0);
could use le32_to_cpup() probably
> + break;
> + case IIO_BE:
> + *val = be32_to_cpu(tmp) >> 8;
> + break;
> + default:
> + return -EINVAL;
> + }
>
> - return buf[0] | (buf[1] << 8);
> + return 0;
> }
>
> static int vz89x_read_raw(struct iio_dev *indio_dev,
> @@ -196,15 +271,15 @@ static int vz89x_read_raw(struct iio_dev *indio_dev,
> if (ret)
> return ret;
>
> - switch (chan->address) {
> - case VZ89X_VOC_CO2_IDX:
> - case VZ89X_VOC_SHORT_IDX:
> - case VZ89X_VOC_TVOC_IDX:
> + switch (chan->type) {
> + case IIO_CONCENTRATION:
> *val = data->buffer[chan->address];
> return IIO_VAL_INT;
> - case VZ89X_VOC_RESISTANCE_IDX:
> - *val = vz89x_get_resistance_reading(data);
> - 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;
> }
> @@ -219,12 +294,12 @@ static int vz89x_read_raw(struct iio_dev *indio_dev,
> }
> break;
> case IIO_CHAN_INFO_OFFSET:
> - switch (chan->address) {
> - case VZ89X_VOC_CO2_IDX:
> + switch (chan->channel2) {
> + case IIO_MOD_CO2:
> *val = 44;
> *val2 = 250000;
> return IIO_VAL_INT_PLUS_MICRO;
> - case VZ89X_VOC_TVOC_IDX:
> + case IIO_MOD_VOC:
> *val = -13;
> return IIO_VAL_INT;
> default:
> @@ -241,11 +316,20 @@ static const struct iio_info vz89x_info = {
> .driver_module = THIS_MODULE,
> };
>
> +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 iio_dev *indio_dev;
> struct vz89x_data *data;
> + const struct of_device_id *of_id;
> + int chip_id;
>
> indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> if (!indio_dev)
> @@ -260,13 +344,15 @@ static int vz89x_probe(struct i2c_client *client,
> else
> return -EOPNOTSUPP;
>
> + of_id = of_match_device(vz89x_dt_ids, &client->dev);
> + if (!of_id)
> + chip_id = id->driver_data;
> + else
> + chip_id = (unsigned long)of_id->data;
> +
> i2c_set_clientdata(client, indio_dev);
> data->client = client;
> data->last_update = jiffies - HZ;
> - data->cmd = VZ89X_REG_MEASUREMENT;
> - data->write_size = 3;
> - data->read_size = VZ89X_REG_MEASUREMENT_SIZE;
> - data->valid = &vz89x_measurement_is_valid;
> mutex_init(&data->lock);
>
> indio_dev->dev.parent = &client->dev;
> @@ -274,24 +360,35 @@ static int vz89x_probe(struct i2c_client *client,
> indio_dev->name = dev_name(&client->dev);
> indio_dev->modes = INDIO_DIRECT_MODE;
>
> - indio_dev->channels = vz89x_channels;
> - indio_dev->num_channels = ARRAY_SIZE(vz89x_channels);
> + switch (chip_id) {
> + case VZ89X:
> + indio_dev->channels = vz89x_channels;
> + indio_dev->num_channels = ARRAY_SIZE(vz89x_channels);
other drivers often use a constant chip_info struct which is used to
declare chip variants (less code, more data)
> + data->cmd = VZ89X_REG_MEASUREMENT;
> + data->write_size = VZ89X_REG_WRITE_SIZE;
> + data->read_size = VZ89X_REG_MEASUREMENT_SIZE;
> + data->valid = &vz89x_measurement_is_valid;
> + break;
> + case VZ89TE:
> + indio_dev->channels = vz89te_channels;
> + indio_dev->num_channels = ARRAY_SIZE(vz89te_channels);
> + data->cmd = VZ89TE_REG_MEASUREMENT;
> + data->write_size = VZ89TE_REG_WRITE_SIZE;
> + data->read_size = VZ89TE_REG_MEASUREMENT_SIZE;
> + data->valid = &vz89te_measurement_is_valid;
> + break;
> + }
>
> return devm_iio_device_register(&client->dev, indio_dev);
> }
>
> static const struct i2c_device_id vz89x_id[] = {
> { "vz89x", VZ89X },
> + { "vz89te", VZ89TE },
> { }
> };
> MODULE_DEVICE_TABLE(i2c, vz89x_id);
>
> -static const struct of_device_id vz89x_dt_ids[] = {
> - { .compatible = "sgx,vz89x", .data = (void *) VZ89X },
> - { }
> -};
> -MODULE_DEVICE_TABLE(of, vz89x_dt_ids);
> -
> static struct i2c_driver vz89x_driver = {
> .driver = {
> .name = "vz89x",
>
--
Peter Meerwald-Stadler
+43-664-2444418 (mobile)
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