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iio: chemical: vz89x: add support for VZ89TE part 

Add support the VZ89TE variant which removes the voc_short channel,
and has CRC check for data transactions.

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Matt Ranostay 2016-08-24 23:44:48 -07:00 committed by Jonathan Cameron
parent 8376882f16
commit 0a735aa07f
1 changed files with 98 additions and 15 deletions
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113
drivers/iio/chemical/vz89x.c
View File

@ -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:
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);