From nobody Sat Oct 4 14:13:15 2025 Received: from out-186.mta0.migadu.com (out-186.mta0.migadu.com [91.218.175.186]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8D08F3112C4 for ; Fri, 15 Aug 2025 16:47:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.186 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755276448; cv=none; b=DrbZ9NgDqGLmrqwLFQ6vcbp7/rIcGL1pWwqkbTwOL267lBTCyosYkibwkyYxrvjsjR6k4zlTtaKqkL/W5IGYqnLIC5iVDjBafYpW9qFNy6/vNPpv67v/p7k+8MC4qST/Appq5hvLQhgm+ap5253OBPEc18ssvaFLZO+k00dMJCg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755276448; c=relaxed/simple; bh=GnLf98a0XvBXfLq1B2oc1iFXcdrbZqoXmlyUC+Wy7h4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NToiEfQSXgYLm6ViMyOFJ6uO99TqHabGecJ64uPu/itNcClJ3MC+ngnJCnzFKA4Zmd3/uXstTBC5+G0NytuCQ9/tAhVWTXYYnlMCW9vTGZ0SXqedwXF7biNQ1ByehavcLmmtfcmE5x8qeezvqLmIChashjrZlwdD4dcF+XOe1rY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=watter.com; spf=pass smtp.mailfrom=linux.dev; arc=none smtp.client-ip=91.218.175.186 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=watter.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Ben Collins To: Jonathan Cameron , David Lechner , =?UTF-8?q?Nuno=20S=C3=A1?= , Andy Shevchenko Cc: Ben Collins , linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 3/5] iio: mcp9600: Recognize chip id for mcp9601 Date: Fri, 15 Aug 2025 16:46:05 +0000 Message-ID: <20250815164627.22002-4-bcollins@watter.com> In-Reply-To: <20250815164627.22002-1-bcollins@watter.com> References: <20250815164627.22002-1-bcollins@watter.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" 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. Signed-off-by: Ben Collins --- drivers/iio/temperature/Kconfig | 8 +++-- drivers/iio/temperature/mcp9600.c | 51 +++++++++++++++++++++++++------ 2 files changed, 46 insertions(+), 13 deletions(-) diff --git a/drivers/iio/temperature/Kconfig b/drivers/iio/temperature/Kcon= fig index 1244d8e17d504..e14ea6ebc7a24 100644 --- a/drivers/iio/temperature/Kconfig +++ b/drivers/iio/temperature/Kconfig @@ -173,11 +173,13 @@ config MAX31865 will be called max31865. =20 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 + and similar thermocouple EMF converters connected via I2C. =20 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/mc= p9600.c index 40906bb200ec9..c18ae17b6d82f 100644 --- a/drivers/iio/temperature/mcp9600.c +++ b/drivers/iio/temperature/mcp9600.c @@ -42,6 +42,7 @@ =20 /* MCP9600 device id value */ #define MCP9600_DEVICE_ID_MCP9600 0x40 +#define MCP9600_DEVICE_ID_MCP9601 0x41 =20 #define MCP9600_ALERT_COUNT 4 =20 @@ -123,6 +124,11 @@ static const struct iio_chan_spec mcp9600_channels[][2= ] =3D { MCP9600_CHANNELS(2, 0, 2, 0), /* Alerts: 1 2 3 4 */ }; =20 +struct mcp_chip_info { + u8 chip_id; + const char *chip_name; +}; + struct mcp9600_data { struct i2c_client *client; }; @@ -416,16 +422,29 @@ static int mcp9600_probe_alerts(struct iio_dev *indio= _dev) =20 static int mcp9600_probe(struct i2c_client *client) { + const struct mcp_chip_info *chip_info =3D i2c_get_match_data(client); struct iio_dev *indio_dev; struct mcp9600_data *data; - int ret, ch_sel; + int ch_sel, dev_id, ret; + + dev_id =3D i2c_smbus_read_byte_data(client, MCP9600_DEVICE_ID); + if (dev_id < 0) + return dev_err_probe(&client->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 !=3D chip_info->chip_id) + dev_warn(&client->dev, + "Expected id %02x, but device responded with %02\n", + chip_info->chip_id, dev_id); + break; =20 - ret =3D 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 !=3D MCP9600_DEVICE_ID_MCP9600) - dev_warn(&client->dev, "Expected ID %x, got %x\n", - MCP9600_DEVICE_ID_MCP9600, ret); + default: + dev_warn(&client->dev, "Unknown id %x, using %x\n", dev_id, + chip_info->chip_id); + } =20 indio_dev =3D devm_iio_device_alloc(&client->dev, sizeof(*data)); if (!indio_dev) @@ -439,7 +458,7 @@ static int mcp9600_probe(struct i2c_client *client) return ch_sel; =20 indio_dev->info =3D &mcp9600_info; - indio_dev->name =3D "mcp9600"; + indio_dev->name =3D chip_info->chip_name; indio_dev->modes =3D INDIO_DIRECT_MODE; indio_dev->channels =3D mcp9600_channels[ch_sel]; indio_dev->num_channels =3D ARRAY_SIZE(mcp9600_channels[ch_sel]); @@ -447,14 +466,26 @@ static int mcp9600_probe(struct i2c_client *client) return devm_iio_device_register(&client->dev, indio_dev); } =20 +static const struct mcp_chip_info mcp9600_chip_info =3D { + .chip_id =3D MCP9600_DEVICE_ID_MCP9600, + .chip_name =3D "mcp9600", +}; + +static const struct mcp_chip_info mcp9601_chip_info =3D { + .chip_id =3D MCP9600_DEVICE_ID_MCP9601, + .chip_name =3D "mcp9601", +}; + static const struct i2c_device_id mcp9600_id[] =3D { - { "mcp9600" }, + { "mcp9600", .driver_data =3D (kernel_ulong_t)&mcp9600_chip_info }, + { "mcp9601", .driver_data =3D (kernel_ulong_t)&mcp9601_chip_info }, { } }; MODULE_DEVICE_TABLE(i2c, mcp9600_id); =20 static const struct of_device_id mcp9600_of_match[] =3D { - { .compatible =3D "microchip,mcp9600" }, + { .compatible =3D "microchip,mcp9600", .data =3D &mcp9600_chip_info }, + { .compatible =3D "microchip,mcp9601", .data =3D &mcp9601_chip_info }, { } }; MODULE_DEVICE_TABLE(of, mcp9600_of_match); --=20 2.50.1