From 5efd60c974a2c2647a2ce87fb2e396011274cfed Mon Sep 17 00:00:00 2001 From: Ben Collins Date: Fri, 22 Aug 2025 09:23:53 -0400 Subject: [PATCH] iio: mcp9600: Recognize chip id for mcp9601 The current driver works with mcp9601, but emits a warning because it does not recognize the chip id. MCP9601 is a superset of MCP9600. The drivers works without changes on this chipset. However, the 9601 chip supports open/closed-circuit detection if wired properly, so we'll need to be able to differentiate between them. Moved "struct mcp9600_data" up in the file since a later patch will need it and chip_info before the declarations. Signed-off-by: Ben Collins Reviewed-by: David Lechner Link: https://patch.msgid.link/20250822-upstream-changes-v8-4-40bb1739e3e2@watter.com Signed-off-by: Jonathan Cameron --- drivers/iio/temperature/Kconfig | 8 ++-- drivers/iio/temperature/mcp9600.c | 68 +++++++++++++++++++++++-------- 2 files changed, 57 insertions(+), 19 deletions(-) diff --git a/drivers/iio/temperature/Kconfig b/drivers/iio/temperature/Kconfig index 1244d8e17d504..9328b2250aced 100644 --- a/drivers/iio/temperature/Kconfig +++ b/drivers/iio/temperature/Kconfig @@ -173,11 +173,13 @@ config MAX31865 will be called max31865. config MCP9600 - tristate "MCP9600 thermocouple EMF converter" + tristate "MCP9600 and similar thermocouple EMF converters" depends on I2C help - If you say yes here you get support for MCP9600 - thermocouple EMF converter connected via I2C. + If you say yes here you get support for... + - MCP9600 + - MCP9601 + ...thermocouple EMF converters connected via I2C. This driver can also be built as a module. If so, the module will be called mcp9600. diff --git a/drivers/iio/temperature/mcp9600.c b/drivers/iio/temperature/mcp9600.c index 40906bb200ec9..51ed780ea72fa 100644 --- a/drivers/iio/temperature/mcp9600.c +++ b/drivers/iio/temperature/mcp9600.c @@ -42,6 +42,7 @@ /* MCP9600 device id value */ #define MCP9600_DEVICE_ID_MCP9600 0x40 +#define MCP9600_DEVICE_ID_MCP9601 0x41 #define MCP9600_ALERT_COUNT 4 @@ -82,6 +83,15 @@ static const struct iio_event_spec mcp9600_events[] = { }, }; +struct mcp_chip_info { + u8 chip_id; + const char *chip_name; +}; + +struct mcp9600_data { + struct i2c_client *client; +}; + #define MCP9600_CHANNELS(hj_num_ev, hj_ev_spec_off, cj_num_ev, cj_ev_spec_off) \ { \ { \ @@ -123,10 +133,6 @@ static const struct iio_chan_spec mcp9600_channels[][2] = { MCP9600_CHANNELS(2, 0, 2, 0), /* Alerts: 1 2 3 4 */ }; -struct mcp9600_data { - struct i2c_client *client; -}; - static int mcp9600_read(struct mcp9600_data *data, struct iio_chan_spec const *chan, int *val) { @@ -416,18 +422,36 @@ static int mcp9600_probe_alerts(struct iio_dev *indio_dev) static int mcp9600_probe(struct i2c_client *client) { + struct device *dev = &client->dev; + const struct mcp_chip_info *chip_info; struct iio_dev *indio_dev; struct mcp9600_data *data; - int ret, ch_sel; + int ch_sel, dev_id; + + chip_info = i2c_get_match_data(client); + if (!chip_info) + return dev_err_probe(dev, -ENODEV, + "No chip-info found for device\n"); + + dev_id = i2c_smbus_read_byte_data(client, MCP9600_DEVICE_ID); + if (dev_id < 0) + return dev_err_probe(dev, dev_id, "Failed to read device ID\n"); + + switch (dev_id) { + case MCP9600_DEVICE_ID_MCP9600: + case MCP9600_DEVICE_ID_MCP9601: + if (dev_id != chip_info->chip_id) + dev_warn(dev, + "Expected id %02x, but device responded with %02x\n", + chip_info->chip_id, dev_id); + break; - ret = i2c_smbus_read_byte_data(client, MCP9600_DEVICE_ID); - if (ret < 0) - return dev_err_probe(&client->dev, ret, "Failed to read device ID\n"); - if (ret != MCP9600_DEVICE_ID_MCP9600) - dev_warn(&client->dev, "Expected ID %x, got %x\n", - MCP9600_DEVICE_ID_MCP9600, ret); + default: + dev_warn(dev, "Unknown id %x, using %x\n", dev_id, + chip_info->chip_id); + } - indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); + indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); if (!indio_dev) return -ENOMEM; @@ -439,22 +463,34 @@ static int mcp9600_probe(struct i2c_client *client) return ch_sel; indio_dev->info = &mcp9600_info; - indio_dev->name = "mcp9600"; + indio_dev->name = chip_info->chip_name; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->channels = mcp9600_channels[ch_sel]; indio_dev->num_channels = ARRAY_SIZE(mcp9600_channels[ch_sel]); - return devm_iio_device_register(&client->dev, indio_dev); + return devm_iio_device_register(dev, indio_dev); } +static const struct mcp_chip_info mcp9600_chip_info = { + .chip_id = MCP9600_DEVICE_ID_MCP9600, + .chip_name = "mcp9600", +}; + +static const struct mcp_chip_info mcp9601_chip_info = { + .chip_id = MCP9600_DEVICE_ID_MCP9601, + .chip_name = "mcp9601", +}; + static const struct i2c_device_id mcp9600_id[] = { - { "mcp9600" }, + { "mcp9600", .driver_data = (kernel_ulong_t)&mcp9600_chip_info }, + { "mcp9601", .driver_data = (kernel_ulong_t)&mcp9601_chip_info }, { } }; MODULE_DEVICE_TABLE(i2c, mcp9600_id); static const struct of_device_id mcp9600_of_match[] = { - { .compatible = "microchip,mcp9600" }, + { .compatible = "microchip,mcp9600", .data = &mcp9600_chip_info }, + { .compatible = "microchip,mcp9601", .data = &mcp9601_chip_info }, { } }; MODULE_DEVICE_TABLE(of, mcp9600_of_match); -- 2.47.3