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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /drivers/hwmon/tmp421.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'drivers/hwmon/tmp421.c')
-rw-r--r--drivers/hwmon/tmp421.c483
1 files changed, 483 insertions, 0 deletions
diff --git a/drivers/hwmon/tmp421.c b/drivers/hwmon/tmp421.c
new file mode 100644
index 000000000..ed00ccfdd
--- /dev/null
+++ b/drivers/hwmon/tmp421.c
@@ -0,0 +1,483 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* tmp421.c
+ *
+ * Copyright (C) 2009 Andre Prendel <andre.prendel@gmx.de>
+ * Preliminary support by:
+ * Melvin Rook, Raymond Ng
+ */
+
+/*
+ * Driver for the Texas Instruments TMP421 SMBus temperature sensor IC.
+ * Supported models: TMP421, TMP422, TMP423, TMP441, TMP442
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/jiffies.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/sysfs.h>
+
+/* Addresses to scan */
+static const unsigned short normal_i2c[] = { 0x2a, 0x4c, 0x4d, 0x4e, 0x4f,
+ I2C_CLIENT_END };
+
+enum chips { tmp421, tmp422, tmp423, tmp441, tmp442 };
+
+#define MAX_CHANNELS 4
+/* The TMP421 registers */
+#define TMP421_STATUS_REG 0x08
+#define TMP421_CONFIG_REG_1 0x09
+#define TMP421_CONFIG_REG_2 0x0A
+#define TMP421_CONFIG_REG_REN(x) (BIT(3 + (x)))
+#define TMP421_CONFIG_REG_REN_MASK GENMASK(6, 3)
+#define TMP421_CONVERSION_RATE_REG 0x0B
+#define TMP421_N_FACTOR_REG_1 0x21
+#define TMP421_MANUFACTURER_ID_REG 0xFE
+#define TMP421_DEVICE_ID_REG 0xFF
+
+static const u8 TMP421_TEMP_MSB[MAX_CHANNELS] = { 0x00, 0x01, 0x02, 0x03 };
+static const u8 TMP421_TEMP_LSB[MAX_CHANNELS] = { 0x10, 0x11, 0x12, 0x13 };
+
+/* Flags */
+#define TMP421_CONFIG_SHUTDOWN 0x40
+#define TMP421_CONFIG_RANGE 0x04
+
+/* Manufacturer / Device ID's */
+#define TMP421_MANUFACTURER_ID 0x55
+#define TMP421_DEVICE_ID 0x21
+#define TMP422_DEVICE_ID 0x22
+#define TMP423_DEVICE_ID 0x23
+#define TMP441_DEVICE_ID 0x41
+#define TMP442_DEVICE_ID 0x42
+
+static const struct i2c_device_id tmp421_id[] = {
+ { .name = "tmp421", .driver_data = 2 },
+ { .name = "tmp422", .driver_data = 3 },
+ { .name = "tmp423", .driver_data = 4 },
+ { .name = "tmp441", .driver_data = 2 },
+ { .name = "tmp442", .driver_data = 3 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, tmp421_id);
+
+static const struct of_device_id __maybe_unused tmp421_of_match[] = {
+ {
+ .compatible = "ti,tmp421",
+ .data = (void *)2
+ },
+ {
+ .compatible = "ti,tmp422",
+ .data = (void *)3
+ },
+ {
+ .compatible = "ti,tmp423",
+ .data = (void *)4
+ },
+ {
+ .compatible = "ti,tmp441",
+ .data = (void *)2
+ },
+ {
+ .compatible = "ti,tmp442",
+ .data = (void *)3
+ },
+ { },
+};
+MODULE_DEVICE_TABLE(of, tmp421_of_match);
+
+struct tmp421_channel {
+ const char *label;
+ bool enabled;
+ s16 temp;
+};
+
+struct tmp421_data {
+ struct i2c_client *client;
+ u32 temp_config[MAX_CHANNELS + 1];
+ struct hwmon_channel_info temp_info;
+ const struct hwmon_channel_info *info[2];
+ struct hwmon_chip_info chip;
+ bool valid;
+ unsigned long last_updated;
+ unsigned long channels;
+ u8 config;
+ struct tmp421_channel channel[MAX_CHANNELS];
+};
+
+static int temp_from_raw(u16 reg, bool extended)
+{
+ /* Mask out status bits */
+ int temp = reg & ~0xf;
+
+ if (extended)
+ temp = temp - 64 * 256;
+ else
+ temp = (s16)temp;
+
+ return DIV_ROUND_CLOSEST(temp * 1000, 256);
+}
+
+static int tmp421_update_device(struct tmp421_data *data)
+{
+ struct i2c_client *client = data->client;
+ int ret = 0;
+ int i;
+
+ if (time_after(jiffies, data->last_updated + (HZ / 2)) ||
+ !data->valid) {
+ data->valid = false;
+ ret = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
+ if (ret < 0)
+ return ret;
+ data->config = ret;
+
+ for (i = 0; i < data->channels; i++) {
+ ret = i2c_smbus_read_byte_data(client, TMP421_TEMP_MSB[i]);
+ if (ret < 0)
+ return ret;
+ data->channel[i].temp = ret << 8;
+
+ ret = i2c_smbus_read_byte_data(client, TMP421_TEMP_LSB[i]);
+ if (ret < 0)
+ return ret;
+ data->channel[i].temp |= ret;
+ }
+ data->last_updated = jiffies;
+ data->valid = true;
+ }
+ return 0;
+}
+
+static int tmp421_enable_channels(struct tmp421_data *data)
+{
+ int err;
+ struct i2c_client *client = data->client;
+ struct device *dev = &client->dev;
+ int old = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_2);
+ int new, i;
+
+ if (old < 0) {
+ dev_err(dev, "error reading register, can't disable channels\n");
+ return old;
+ }
+
+ new = old & ~TMP421_CONFIG_REG_REN_MASK;
+ for (i = 0; i < data->channels; i++)
+ if (data->channel[i].enabled)
+ new |= TMP421_CONFIG_REG_REN(i);
+
+ if (new == old)
+ return 0;
+
+ err = i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_2, new);
+ if (err < 0)
+ dev_err(dev, "error writing register, can't disable channels\n");
+
+ return err;
+}
+
+static int tmp421_read(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long *val)
+{
+ struct tmp421_data *tmp421 = dev_get_drvdata(dev);
+ int ret = 0;
+
+ ret = tmp421_update_device(tmp421);
+ if (ret)
+ return ret;
+
+ switch (attr) {
+ case hwmon_temp_input:
+ if (!tmp421->channel[channel].enabled)
+ return -ENODATA;
+ *val = temp_from_raw(tmp421->channel[channel].temp,
+ tmp421->config & TMP421_CONFIG_RANGE);
+ return 0;
+ case hwmon_temp_fault:
+ if (!tmp421->channel[channel].enabled)
+ return -ENODATA;
+ /*
+ * Any of OPEN or /PVLD bits indicate a hardware mulfunction
+ * and the conversion result may be incorrect
+ */
+ *val = !!(tmp421->channel[channel].temp & 0x03);
+ return 0;
+ case hwmon_temp_enable:
+ *val = tmp421->channel[channel].enabled;
+ return 0;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+}
+
+static int tmp421_read_string(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, const char **str)
+{
+ struct tmp421_data *data = dev_get_drvdata(dev);
+
+ *str = data->channel[channel].label;
+
+ return 0;
+}
+
+static int tmp421_write(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long val)
+{
+ struct tmp421_data *data = dev_get_drvdata(dev);
+ int ret;
+
+ switch (attr) {
+ case hwmon_temp_enable:
+ data->channel[channel].enabled = val;
+ ret = tmp421_enable_channels(data);
+ break;
+ default:
+ ret = -EOPNOTSUPP;
+ }
+
+ return ret;
+}
+
+static umode_t tmp421_is_visible(const void *data, enum hwmon_sensor_types type,
+ u32 attr, int channel)
+{
+ switch (attr) {
+ case hwmon_temp_fault:
+ case hwmon_temp_input:
+ case hwmon_temp_label:
+ return 0444;
+ case hwmon_temp_enable:
+ return 0644;
+ default:
+ return 0;
+ }
+}
+
+static int tmp421_init_client(struct tmp421_data *data)
+{
+ int config, config_orig;
+ struct i2c_client *client = data->client;
+
+ /* Set the conversion rate to 2 Hz */
+ i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05);
+
+ /* Start conversions (disable shutdown if necessary) */
+ config = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
+ if (config < 0) {
+ dev_err(&client->dev,
+ "Could not read configuration register (%d)\n", config);
+ return config;
+ }
+
+ config_orig = config;
+ config &= ~TMP421_CONFIG_SHUTDOWN;
+
+ if (config != config_orig) {
+ dev_info(&client->dev, "Enable monitoring chip\n");
+ i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_1, config);
+ }
+
+ return tmp421_enable_channels(data);
+}
+
+static int tmp421_detect(struct i2c_client *client,
+ struct i2c_board_info *info)
+{
+ enum chips kind;
+ struct i2c_adapter *adapter = client->adapter;
+ static const char * const names[] = {
+ "TMP421", "TMP422", "TMP423",
+ "TMP441", "TMP442"
+ };
+ int addr = client->addr;
+ u8 reg;
+
+ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+ return -ENODEV;
+
+ reg = i2c_smbus_read_byte_data(client, TMP421_MANUFACTURER_ID_REG);
+ if (reg != TMP421_MANUFACTURER_ID)
+ return -ENODEV;
+
+ reg = i2c_smbus_read_byte_data(client, TMP421_CONVERSION_RATE_REG);
+ if (reg & 0xf8)
+ return -ENODEV;
+
+ reg = i2c_smbus_read_byte_data(client, TMP421_STATUS_REG);
+ if (reg & 0x7f)
+ return -ENODEV;
+
+ reg = i2c_smbus_read_byte_data(client, TMP421_DEVICE_ID_REG);
+ switch (reg) {
+ case TMP421_DEVICE_ID:
+ kind = tmp421;
+ break;
+ case TMP422_DEVICE_ID:
+ if (addr == 0x2a)
+ return -ENODEV;
+ kind = tmp422;
+ break;
+ case TMP423_DEVICE_ID:
+ if (addr != 0x4c && addr != 0x4d)
+ return -ENODEV;
+ kind = tmp423;
+ break;
+ case TMP441_DEVICE_ID:
+ kind = tmp441;
+ break;
+ case TMP442_DEVICE_ID:
+ if (addr != 0x4c && addr != 0x4d)
+ return -ENODEV;
+ kind = tmp442;
+ break;
+ default:
+ return -ENODEV;
+ }
+
+ strscpy(info->type, tmp421_id[kind].name, I2C_NAME_SIZE);
+ dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n",
+ names[kind], client->addr);
+
+ return 0;
+}
+
+static int tmp421_probe_child_from_dt(struct i2c_client *client,
+ struct device_node *child,
+ struct tmp421_data *data)
+
+{
+ struct device *dev = &client->dev;
+ u32 i;
+ s32 val;
+ int err;
+
+ err = of_property_read_u32(child, "reg", &i);
+ if (err) {
+ dev_err(dev, "missing reg property of %pOFn\n", child);
+ return err;
+ }
+
+ if (i >= data->channels) {
+ dev_err(dev, "invalid reg %d of %pOFn\n", i, child);
+ return -EINVAL;
+ }
+
+ err = of_property_read_string(child, "label", &data->channel[i].label);
+ if (err == -ENODATA || err == -EILSEQ) {
+ dev_err(dev, "invalid label property in %pOFn\n", child);
+ return err;
+ }
+ if (data->channel[i].label)
+ data->temp_config[i] |= HWMON_T_LABEL;
+
+ data->channel[i].enabled = of_device_is_available(child);
+
+ err = of_property_read_s32(child, "ti,n-factor", &val);
+ if (!err) {
+ if (i == 0) {
+ dev_err(dev, "n-factor can't be set for internal channel\n");
+ return -EINVAL;
+ }
+
+ if (val > 127 || val < -128) {
+ dev_err(dev, "n-factor for channel %d invalid (%d)\n",
+ i, val);
+ return -EINVAL;
+ }
+ i2c_smbus_write_byte_data(client, TMP421_N_FACTOR_REG_1 + i - 1,
+ val);
+ }
+
+ return 0;
+}
+
+static int tmp421_probe_from_dt(struct i2c_client *client, struct tmp421_data *data)
+{
+ struct device *dev = &client->dev;
+ const struct device_node *np = dev->of_node;
+ int err;
+
+ for_each_child_of_node_scoped(np, child) {
+ if (strcmp(child->name, "channel"))
+ continue;
+
+ err = tmp421_probe_child_from_dt(client, child, data);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
+static const struct hwmon_ops tmp421_ops = {
+ .is_visible = tmp421_is_visible,
+ .read = tmp421_read,
+ .read_string = tmp421_read_string,
+ .write = tmp421_write,
+};
+
+static int tmp421_probe(struct i2c_client *client)
+{
+ struct device *dev = &client->dev;
+ struct device *hwmon_dev;
+ struct tmp421_data *data;
+ int i, err;
+
+ data = devm_kzalloc(dev, sizeof(struct tmp421_data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->channels = (unsigned long)i2c_get_match_data(client);
+ data->client = client;
+
+ for (i = 0; i < data->channels; i++) {
+ data->temp_config[i] = HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_ENABLE;
+ data->channel[i].enabled = true;
+ }
+
+ err = tmp421_probe_from_dt(client, data);
+ if (err)
+ return err;
+
+ err = tmp421_init_client(data);
+ if (err)
+ return err;
+
+ data->chip.ops = &tmp421_ops;
+ data->chip.info = data->info;
+
+ data->info[0] = &data->temp_info;
+
+ data->temp_info.type = hwmon_temp;
+ data->temp_info.config = data->temp_config;
+
+ hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
+ data,
+ &data->chip,
+ NULL);
+ return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static struct i2c_driver tmp421_driver = {
+ .class = I2C_CLASS_HWMON,
+ .driver = {
+ .name = "tmp421",
+ .of_match_table = of_match_ptr(tmp421_of_match),
+ },
+ .probe = tmp421_probe,
+ .id_table = tmp421_id,
+ .detect = tmp421_detect,
+ .address_list = normal_i2c,
+};
+
+module_i2c_driver(tmp421_driver);
+
+MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>");
+MODULE_DESCRIPTION("Texas Instruments TMP421/422/423/441/442 temperature sensor driver");
+MODULE_LICENSE("GPL");