On 25/08/16 07:44, Matt Ranostay wrote:
> Add support the VZ89TE variant which removes the voc_short channel,
> and has CRC check for data transactions.
>
> Signed-off-by: Matt Ranostay <mranostay@xxxxxxxxx>
Minor comment inline.
Applied to the togreg branch of iio.git - initially pushed
out as testing for the autobuilders to play with it.
Thanks,
Jonathan
> ---
> drivers/iio/chemical/vz89x.c | 113 +++++++++++++++++++++++++++++++++++++------
> 1 file changed, 98 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/iio/chemical/vz89x.c b/drivers/iio/chemical/vz89x.c
> index aa6ebc084e19..289d2919deea 100644
> --- a/drivers/iio/chemical/vz89x.c
> +++ b/drivers/iio/chemical/vz89x.c
> @@ -34,8 +34,17 @@
> #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;
> @@ -47,7 +56,7 @@ struct vz89x_data {
> int (*xfer)(struct vz89x_data *data, u8 cmd);
>
> unsigned long last_update;
> - u8 buffer[VZ89X_REG_MEASUREMENT_RD_SIZE];
> + u8 buffer[VZ89TE_REG_MEASUREMENT_RD_SIZE];
> };
>
> struct vz89x_chip_data {
> @@ -90,6 +99,40 @@ 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 = {
> + .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,
> + },
> },
> };
>
> @@ -121,13 +164,28 @@ static bool vz89x_measurement_is_valid(struct vz89x_data *data)
> 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[3] = { cmd, 0, 0};
> + u8 buf[6] = { cmd, 0, 0, 0, 0, 0xf3 };
>
> msg[0].addr = client->addr;
> msg[0].flags = client->flags;
> @@ -186,11 +244,24 @@ 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];
> + u8 *tmp = (u8 *) &data->buffer[chan->address];
>
> - return buf[0] | (buf[1] << 8);
> + 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,
> @@ -209,15 +280,15 @@ 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:
Hmm. This rework should probably have been in a separate 'pre' patch.
> + 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;
> }
> @@ -232,12 +303,12 @@ 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:
> @@ -265,10 +336,21 @@ static const struct vz89x_chip_data vz89x_chips[] = {
> .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);
> @@ -319,6 +401,7 @@ static int vz89x_probe(struct i2c_client *client,
>
> static const struct i2c_device_id vz89x_id[] = {
> { "vz89x", VZ89X },
> + { "vz89te", VZ89TE },
> { }
> };
> MODULE_DEVICE_TABLE(i2c, vz89x_id);
>
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