Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
iio: mcp9600: Add support for thermocouple-type
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>
authored by
Ben Collins
and committed by
Jonathan Cameron
46809b9f
5efd60c9
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-1
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-1
drivers/iio/temperature/mcp9600.c
+70
-1
drivers/iio/temperature/mcp9600.c
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#include <linux/iio/events.h>
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#include <linux/iio/iio.h>
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#include <dt-bindings/iio/temperature/thermocouple.h>
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/* MCP9600 registers */
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#define MCP9600_HOT_JUNCTION 0x00
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#define MCP9600_COLD_JUNCTION 0x02
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#define MCP9600_STATUS 0x04
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#define MCP9600_STATUS_ALERT(x) BIT(x)
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#define MCP9600_SENSOR_CFG 0x05
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#define MCP9600_SENSOR_TYPE_MASK GENMASK(6, 4)
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#define MCP9600_ALERT_CFG1 0x08
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#define MCP9600_ALERT_CFG(x) (MCP9600_ALERT_CFG1 + (x - 1))
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#define MCP9600_ALERT_CFG_ENABLE BIT(0)
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[MCP9600_ALERT4] = "alert4",
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};
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/* Map between dt-bindings enum and the chip's type value */
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static const unsigned int mcp9600_type_map[] = {
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[THERMOCOUPLE_TYPE_K] = 0,
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[THERMOCOUPLE_TYPE_J] = 1,
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[THERMOCOUPLE_TYPE_T] = 2,
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[THERMOCOUPLE_TYPE_N] = 3,
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[THERMOCOUPLE_TYPE_S] = 4,
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[THERMOCOUPLE_TYPE_E] = 5,
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[THERMOCOUPLE_TYPE_B] = 6,
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[THERMOCOUPLE_TYPE_R] = 7,
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};
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/* Map thermocouple type to a char for iio info in sysfs */
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static const int mcp9600_tc_types[] = {
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[THERMOCOUPLE_TYPE_K] = 'K',
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[THERMOCOUPLE_TYPE_J] = 'J',
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[THERMOCOUPLE_TYPE_T] = 'T',
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[THERMOCOUPLE_TYPE_N] = 'N',
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[THERMOCOUPLE_TYPE_S] = 'S',
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[THERMOCOUPLE_TYPE_E] = 'E',
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[THERMOCOUPLE_TYPE_B] = 'B',
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[THERMOCOUPLE_TYPE_R] = 'R',
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};
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static const struct iio_event_spec mcp9600_events[] = {
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{
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.type = IIO_EV_TYPE_THRESH,
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struct mcp9600_data {
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struct i2c_client *client;
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u32 thermocouple_type;
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};
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static int mcp9600_config(struct mcp9600_data *data)
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{
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struct i2c_client *client = data->client;
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int ret;
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u8 cfg;
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cfg = FIELD_PREP(MCP9600_SENSOR_TYPE_MASK,
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mcp9600_type_map[data->thermocouple_type]);
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ret = i2c_smbus_write_byte_data(client, MCP9600_SENSOR_CFG, cfg);
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if (ret < 0) {
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dev_err(&client->dev, "Failed to set sensor configuration\n");
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return ret;
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}
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return 0;
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}
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#define MCP9600_CHANNELS(hj_num_ev, hj_ev_spec_off, cj_num_ev, cj_ev_spec_off) \
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{ \
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.type = IIO_TEMP, \
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.address = MCP9600_HOT_JUNCTION, \
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
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BIT(IIO_CHAN_INFO_THERMOCOUPLE_TYPE) | \
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BIT(IIO_CHAN_INFO_SCALE), \
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.event_spec = &mcp9600_events[hj_ev_spec_off], \
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.num_event_specs = hj_num_ev, \
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*val = 62;
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*val2 = 500000;
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return IIO_VAL_INT_PLUS_MICRO;
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case IIO_CHAN_INFO_THERMOCOUPLE_TYPE:
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*val = mcp9600_tc_types[data->thermocouple_type];
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return IIO_VAL_CHAR;
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default:
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return -EINVAL;
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}
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const struct mcp_chip_info *chip_info;
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struct iio_dev *indio_dev;
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struct mcp9600_data *data;
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int ch_sel, dev_id;
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int ch_sel, dev_id, ret;
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chip_info = i2c_get_match_data(client);
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if (!chip_info)
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data = iio_priv(indio_dev);
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data->client = client;
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/* Accept type from dt with default of Type-K. */
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data->thermocouple_type = THERMOCOUPLE_TYPE_K;
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ret = device_property_read_u32(dev, "thermocouple-type",
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&data->thermocouple_type);
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if (ret && ret != -EINVAL)
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return dev_err_probe(dev, ret,
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"Error reading thermocouple-type property\n");
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if (data->thermocouple_type >= ARRAY_SIZE(mcp9600_type_map))
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return dev_err_probe(dev, -EINVAL,
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"Invalid thermocouple-type property %u.\n",
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data->thermocouple_type);
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/* Set initial config. */
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ret = mcp9600_config(data);
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if (ret)
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return ret;
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ch_sel = mcp9600_probe_alerts(indio_dev);
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if (ch_sel < 0)