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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/hwmon/max6642.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/hwmon/max6642.c')
-rw-r--r--drivers/hwmon/max6642.c314
1 files changed, 314 insertions, 0 deletions
diff --git a/drivers/hwmon/max6642.c b/drivers/hwmon/max6642.c
new file mode 100644
index 000000000..47ea34ff7
--- /dev/null
+++ b/drivers/hwmon/max6642.c
@@ -0,0 +1,314 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Driver for +/-1 degree C, SMBus-Compatible Remote/Local Temperature Sensor
+ * with Overtemperature Alarm
+ *
+ * Copyright (C) 2011 AppearTV AS
+ *
+ * Derived from:
+ *
+ * Based on the max1619 driver.
+ * Copyright (C) 2003-2004 Oleksij Rempel <bug-track@fisher-privat.net>
+ * Jean Delvare <jdelvare@suse.de>
+ *
+ * The MAX6642 is a sensor chip made by Maxim.
+ * It reports up to two temperatures (its own plus up to
+ * one external one). Complete datasheet can be
+ * obtained from Maxim's website at:
+ * http://datasheets.maxim-ic.com/en/ds/MAX6642.pdf
+ */
+
+
+#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/mutex.h>
+#include <linux/sysfs.h>
+
+static const unsigned short normal_i2c[] = {
+ 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
+
+/*
+ * The MAX6642 registers
+ */
+
+#define MAX6642_REG_R_MAN_ID 0xFE
+#define MAX6642_REG_R_CONFIG 0x03
+#define MAX6642_REG_W_CONFIG 0x09
+#define MAX6642_REG_R_STATUS 0x02
+#define MAX6642_REG_R_LOCAL_TEMP 0x00
+#define MAX6642_REG_R_LOCAL_TEMPL 0x11
+#define MAX6642_REG_R_LOCAL_HIGH 0x05
+#define MAX6642_REG_W_LOCAL_HIGH 0x0B
+#define MAX6642_REG_R_REMOTE_TEMP 0x01
+#define MAX6642_REG_R_REMOTE_TEMPL 0x10
+#define MAX6642_REG_R_REMOTE_HIGH 0x07
+#define MAX6642_REG_W_REMOTE_HIGH 0x0D
+
+/*
+ * Conversions
+ */
+
+static int temp_from_reg10(int val)
+{
+ return val * 250;
+}
+
+static int temp_from_reg(int val)
+{
+ return val * 1000;
+}
+
+static int temp_to_reg(int val)
+{
+ return val / 1000;
+}
+
+/*
+ * Client data (each client gets its own)
+ */
+
+struct max6642_data {
+ struct i2c_client *client;
+ struct mutex update_lock;
+ bool valid; /* zero until following fields are valid */
+ unsigned long last_updated; /* in jiffies */
+
+ /* registers values */
+ u16 temp_input[2]; /* local/remote */
+ u16 temp_high[2]; /* local/remote */
+ u8 alarms;
+};
+
+/*
+ * Real code
+ */
+
+static void max6642_init_client(struct max6642_data *data,
+ struct i2c_client *client)
+{
+ u8 config;
+
+ /*
+ * Start the conversions.
+ */
+ config = i2c_smbus_read_byte_data(client, MAX6642_REG_R_CONFIG);
+ if (config & 0x40)
+ i2c_smbus_write_byte_data(client, MAX6642_REG_W_CONFIG,
+ config & 0xBF); /* run */
+
+ data->temp_high[0] = i2c_smbus_read_byte_data(client,
+ MAX6642_REG_R_LOCAL_HIGH);
+ data->temp_high[1] = i2c_smbus_read_byte_data(client,
+ MAX6642_REG_R_REMOTE_HIGH);
+}
+
+/* Return 0 if detection is successful, -ENODEV otherwise */
+static int max6642_detect(struct i2c_client *client,
+ struct i2c_board_info *info)
+{
+ struct i2c_adapter *adapter = client->adapter;
+ u8 reg_config, reg_status, man_id;
+
+ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+ return -ENODEV;
+
+ /* identification */
+ man_id = i2c_smbus_read_byte_data(client, MAX6642_REG_R_MAN_ID);
+ if (man_id != 0x4D)
+ return -ENODEV;
+
+ /* sanity check */
+ if (i2c_smbus_read_byte_data(client, 0x04) != 0x4D
+ || i2c_smbus_read_byte_data(client, 0x06) != 0x4D
+ || i2c_smbus_read_byte_data(client, 0xff) != 0x4D)
+ return -ENODEV;
+
+ /*
+ * We read the config and status register, the 4 lower bits in the
+ * config register should be zero and bit 5, 3, 1 and 0 should be
+ * zero in the status register.
+ */
+ reg_config = i2c_smbus_read_byte_data(client, MAX6642_REG_R_CONFIG);
+ if ((reg_config & 0x0f) != 0x00)
+ return -ENODEV;
+
+ /* in between, another round of sanity checks */
+ if (i2c_smbus_read_byte_data(client, 0x04) != reg_config
+ || i2c_smbus_read_byte_data(client, 0x06) != reg_config
+ || i2c_smbus_read_byte_data(client, 0xff) != reg_config)
+ return -ENODEV;
+
+ reg_status = i2c_smbus_read_byte_data(client, MAX6642_REG_R_STATUS);
+ if ((reg_status & 0x2b) != 0x00)
+ return -ENODEV;
+
+ strscpy(info->type, "max6642", I2C_NAME_SIZE);
+
+ return 0;
+}
+
+static struct max6642_data *max6642_update_device(struct device *dev)
+{
+ struct max6642_data *data = dev_get_drvdata(dev);
+ struct i2c_client *client = data->client;
+ u16 val, tmp;
+
+ mutex_lock(&data->update_lock);
+
+ if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
+ dev_dbg(dev, "Updating max6642 data.\n");
+ val = i2c_smbus_read_byte_data(client,
+ MAX6642_REG_R_LOCAL_TEMPL);
+ tmp = (val >> 6) & 3;
+ val = i2c_smbus_read_byte_data(client,
+ MAX6642_REG_R_LOCAL_TEMP);
+ val = (val << 2) | tmp;
+ data->temp_input[0] = val;
+ val = i2c_smbus_read_byte_data(client,
+ MAX6642_REG_R_REMOTE_TEMPL);
+ tmp = (val >> 6) & 3;
+ val = i2c_smbus_read_byte_data(client,
+ MAX6642_REG_R_REMOTE_TEMP);
+ val = (val << 2) | tmp;
+ data->temp_input[1] = val;
+ data->alarms = i2c_smbus_read_byte_data(client,
+ MAX6642_REG_R_STATUS);
+
+ data->last_updated = jiffies;
+ data->valid = true;
+ }
+
+ mutex_unlock(&data->update_lock);
+
+ return data;
+}
+
+/*
+ * Sysfs stuff
+ */
+
+static ssize_t temp_max10_show(struct device *dev,
+ struct device_attribute *dev_attr, char *buf)
+{
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
+ struct max6642_data *data = max6642_update_device(dev);
+
+ return sprintf(buf, "%d\n",
+ temp_from_reg10(data->temp_input[attr->index]));
+}
+
+static ssize_t temp_max_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr);
+ struct max6642_data *data = max6642_update_device(dev);
+
+ return sprintf(buf, "%d\n", temp_from_reg(data->temp_high[attr2->nr]));
+}
+
+static ssize_t temp_max_store(struct device *dev,
+ struct device_attribute *attr, const char *buf,
+ size_t count)
+{
+ struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr);
+ struct max6642_data *data = dev_get_drvdata(dev);
+ unsigned long val;
+ int err;
+
+ err = kstrtoul(buf, 10, &val);
+ if (err < 0)
+ return err;
+
+ mutex_lock(&data->update_lock);
+ data->temp_high[attr2->nr] = clamp_val(temp_to_reg(val), 0, 255);
+ i2c_smbus_write_byte_data(data->client, attr2->index,
+ data->temp_high[attr2->nr]);
+ mutex_unlock(&data->update_lock);
+ return count;
+}
+
+static ssize_t alarm_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ int bitnr = to_sensor_dev_attr(attr)->index;
+ struct max6642_data *data = max6642_update_device(dev);
+ return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
+}
+
+static SENSOR_DEVICE_ATTR_RO(temp1_input, temp_max10, 0);
+static SENSOR_DEVICE_ATTR_RO(temp2_input, temp_max10, 1);
+static SENSOR_DEVICE_ATTR_2_RW(temp1_max, temp_max, 0,
+ MAX6642_REG_W_LOCAL_HIGH);
+static SENSOR_DEVICE_ATTR_2_RW(temp2_max, temp_max, 1,
+ MAX6642_REG_W_REMOTE_HIGH);
+static SENSOR_DEVICE_ATTR_RO(temp2_fault, alarm, 2);
+static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 6);
+static SENSOR_DEVICE_ATTR_RO(temp2_max_alarm, alarm, 4);
+
+static struct attribute *max6642_attrs[] = {
+ &sensor_dev_attr_temp1_input.dev_attr.attr,
+ &sensor_dev_attr_temp2_input.dev_attr.attr,
+ &sensor_dev_attr_temp1_max.dev_attr.attr,
+ &sensor_dev_attr_temp2_max.dev_attr.attr,
+
+ &sensor_dev_attr_temp2_fault.dev_attr.attr,
+ &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
+ &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(max6642);
+
+static int max6642_probe(struct i2c_client *client)
+{
+ struct device *dev = &client->dev;
+ struct max6642_data *data;
+ struct device *hwmon_dev;
+
+ data = devm_kzalloc(dev, sizeof(struct max6642_data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->client = client;
+ mutex_init(&data->update_lock);
+
+ /* Initialize the MAX6642 chip */
+ max6642_init_client(data, client);
+
+ hwmon_dev = devm_hwmon_device_register_with_groups(&client->dev,
+ client->name, data,
+ max6642_groups);
+ return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+/*
+ * Driver data (common to all clients)
+ */
+
+static const struct i2c_device_id max6642_id[] = {
+ { "max6642", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, max6642_id);
+
+static struct i2c_driver max6642_driver = {
+ .class = I2C_CLASS_HWMON,
+ .driver = {
+ .name = "max6642",
+ },
+ .probe_new = max6642_probe,
+ .id_table = max6642_id,
+ .detect = max6642_detect,
+ .address_list = normal_i2c,
+};
+
+module_i2c_driver(max6642_driver);
+
+MODULE_AUTHOR("Per Dalen <per.dalen@appeartv.com>");
+MODULE_DESCRIPTION("MAX6642 sensor driver");
+MODULE_LICENSE("GPL");