bybrooklyn/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-04-18 06:44:00 -04:00
Code Issues Packages Projects Releases Wiki Activity

iio: mcp9600: Add support for thermocouple-type

Browse Source 
dt-bindings documentation for this driver claims to support
thermocouple-type, but the driver does not actually make use of
the property.

Implement usage of the property to configure the chip for the
selected thermocouple-type.

Signed-off-by: Ben Collins <bcollins@watter.com>
Reviewed-by: David Lechner <dlechner@baylibre.com>
Link: https://patch.msgid.link/20250822-upstream-changes-v8-5-40bb1739e3e2@watter.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Ben Collins
2025-08-22 09:23:54 -04:00
committed by Jonathan Cameron
parent 5efd60c974
commit 46809b9f43
1 changed files with 70 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

71
drivers/iio/temperature/mcp9600.c
View File

@@ -22,11 +22,15 @@
#include <linux/iio/events.h>
#include <linux/iio/iio.h>
#include <dt-bindings/iio/temperature/thermocouple.h>
/* MCP9600 registers */
#define MCP9600_HOT_JUNCTION 0x00
#define MCP9600_COLD_JUNCTION 0x02
#define MCP9600_STATUS 0x04
#define MCP9600_STATUS_ALERT(x) BIT(x)
#define MCP9600_SENSOR_CFG 0x05
#define MCP9600_SENSOR_TYPE_MASK GENMASK(6, 4)
#define MCP9600_ALERT_CFG1 0x08
#define MCP9600_ALERT_CFG(x) (MCP9600_ALERT_CFG1 + (x - 1))
#define MCP9600_ALERT_CFG_ENABLE BIT(0)
@@ -66,6 +70,30 @@ static const char * const mcp9600_alert_name[MCP9600_ALERT_COUNT] = {
[MCP9600_ALERT4] = "alert4",
};
/* Map between dt-bindings enum and the chip's type value */
static const unsigned int mcp9600_type_map[] = {
[THERMOCOUPLE_TYPE_K] = 0,
[THERMOCOUPLE_TYPE_J] = 1,
[THERMOCOUPLE_TYPE_T] = 2,
[THERMOCOUPLE_TYPE_N] = 3,
[THERMOCOUPLE_TYPE_S] = 4,
[THERMOCOUPLE_TYPE_E] = 5,
[THERMOCOUPLE_TYPE_B] = 6,
[THERMOCOUPLE_TYPE_R] = 7,
};
/* Map thermocouple type to a char for iio info in sysfs */
static const int mcp9600_tc_types[] = {
[THERMOCOUPLE_TYPE_K] = 'K',
[THERMOCOUPLE_TYPE_J] = 'J',
[THERMOCOUPLE_TYPE_T] = 'T',
[THERMOCOUPLE_TYPE_N] = 'N',
[THERMOCOUPLE_TYPE_S] = 'S',
[THERMOCOUPLE_TYPE_E] = 'E',
[THERMOCOUPLE_TYPE_B] = 'B',
[THERMOCOUPLE_TYPE_R] = 'R',
};
static const struct iio_event_spec mcp9600_events[] = {
{
.type = IIO_EV_TYPE_THRESH,
@@ -90,14 +118,34 @@ struct mcp_chip_info {
struct mcp9600_data {
struct i2c_client *client;
u32 thermocouple_type;
};
static int mcp9600_config(struct mcp9600_data *data)
{
struct i2c_client *client = data->client;
int ret;
u8 cfg;
cfg = FIELD_PREP(MCP9600_SENSOR_TYPE_MASK,
mcp9600_type_map[data->thermocouple_type]);
ret = i2c_smbus_write_byte_data(client, MCP9600_SENSOR_CFG, cfg);
if (ret < 0) {
dev_err(&client->dev, "Failed to set sensor configuration\n");
return ret;
}
return 0;
}
#define MCP9600_CHANNELS(hj_num_ev, hj_ev_spec_off, cj_num_ev, cj_ev_spec_off) \
{ \
{ \
.type = IIO_TEMP, \
.address = MCP9600_HOT_JUNCTION, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_THERMOCOUPLE_TYPE) | \
BIT(IIO_CHAN_INFO_SCALE), \
.event_spec = &mcp9600_events[hj_ev_spec_off], \
.num_event_specs = hj_num_ev, \
@@ -165,6 +213,9 @@ static int mcp9600_read_raw(struct iio_dev *indio_dev,
*val = 62;
*val2 = 500000;
return IIO_VAL_INT_PLUS_MICRO;
case IIO_CHAN_INFO_THERMOCOUPLE_TYPE:
*val = mcp9600_tc_types[data->thermocouple_type];
return IIO_VAL_CHAR;
default:
return -EINVAL;
}
@@ -426,7 +477,7 @@ static int mcp9600_probe(struct i2c_client *client)
const struct mcp_chip_info *chip_info;
struct iio_dev *indio_dev;
struct mcp9600_data *data;
int ch_sel, dev_id;
int ch_sel, dev_id, ret;
chip_info = i2c_get_match_data(client);
if (!chip_info)
@@ -458,6 +509,24 @@ static int mcp9600_probe(struct i2c_client *client)
data = iio_priv(indio_dev);
data->client = client;
/* Accept type from dt with default of Type-K. */
data->thermocouple_type = THERMOCOUPLE_TYPE_K;
ret = device_property_read_u32(dev, "thermocouple-type",
&data->thermocouple_type);
if (ret && ret != -EINVAL)
return dev_err_probe(dev, ret,
"Error reading thermocouple-type property\n");
if (data->thermocouple_type >= ARRAY_SIZE(mcp9600_type_map))
return dev_err_probe(dev, -EINVAL,
"Invalid thermocouple-type property %u.\n",
data->thermocouple_type);
/* Set initial config. */
ret = mcp9600_config(data);
if (ret)
return ret;
ch_sel = mcp9600_probe_alerts(indio_dev);
if (ch_sel < 0)
return ch_sel;