// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (c) 2011 David George <david.george@ska.ac.za> * * based on adm1021.c * some credit to Christoph Scheurer, but largely a rewrite */ #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> /* Addresses to scan */ static const unsigned short max1668_addr_list[] = { 0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END }; /* max1668 registers */ #define MAX1668_REG_TEMP(nr) (nr) #define MAX1668_REG_STAT1 0x05 #define MAX1668_REG_STAT2 0x06 #define MAX1668_REG_MAN_ID 0xfe #define MAX1668_REG_DEV_ID 0xff /* limits */ /* write high limits */ #define MAX1668_REG_LIMH_WR(nr) (0x13 + 2 * (nr)) /* write low limits */ #define MAX1668_REG_LIML_WR(nr) (0x14 + 2 * (nr)) /* read high limits */ #define MAX1668_REG_LIMH_RD(nr) (0x08 + 2 * (nr)) /* read low limits */ #define MAX1668_REG_LIML_RD(nr) (0x09 + 2 * (nr)) /* manufacturer and device ID Constants */ #define MAN_ID_MAXIM 0x4d #define DEV_ID_MAX1668 0x3 #define DEV_ID_MAX1805 0x5 #define DEV_ID_MAX1989 0xb /* read only mode module parameter */ static bool read_only; module_param(read_only, bool, 0); MODULE_PARM_DESC(read_only, "Don't set any values, read only mode"); enum chips { max1668, max1805, max1989 }; struct max1668_data { struct i2c_client *client; const struct attribute_group *groups[3]; enum chips type; struct mutex update_lock; char valid; /* !=0 if following fields are valid */ unsigned long last_updated; /* In jiffies */ /* 1x local and 4x remote */ s8 temp_max[5]; s8 temp_min[5]; s8 temp[5]; u16 alarms; }; static struct max1668_data *max1668_update_device(struct device *dev) { struct max1668_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; struct max1668_data *ret = data; s32 val; int i; mutex_lock(&data->update_lock); if (data->valid && !time_after(jiffies, data->last_updated + HZ + HZ / 2)) goto abort; for (i = 0; i < 5; i++) { val = i2c_smbus_read_byte_data(client, MAX1668_REG_TEMP(i)); if (unlikely(val < 0)) { ret = ERR_PTR(val); goto abort; } data->temp[i] = (s8) val; val = i2c_smbus_read_byte_data(client, MAX1668_REG_LIMH_RD(i)); if (unlikely(val < 0)) { ret = ERR_PTR(val); goto abort; } data->temp_max[i] = (s8) val; val = i2c_smbus_read_byte_data(client, MAX1668_REG_LIML_RD(i)); if (unlikely(val < 0)) { ret = ERR_PTR(val); goto abort; } data->temp_min[i] = (s8) val; } val = i2c_smbus_read_byte_data(client, MAX1668_REG_STAT1); if (unlikely(val < 0)) { ret = ERR_PTR(val); goto abort; } data->alarms = val << 8; val = i2c_smbus_read_byte_data(client, MAX1668_REG_STAT2); if (unlikely(val < 0)) { ret = ERR_PTR(val); goto abort; } data->alarms |= val; data->last_updated = jiffies; data->valid = 1; abort: mutex_unlock(&data->update_lock); return ret; } static ssize_t show_temp(struct device *dev, struct device_attribute *devattr, char *buf) { int index = to_sensor_dev_attr(devattr)->index; struct max1668_data *data = max1668_update_device(dev); if (IS_ERR(data)) return PTR_ERR(data); return sprintf(buf, "%d\n", data->temp[index] * 1000); } static ssize_t show_temp_max(struct device *dev, struct device_attribute *devattr, char *buf) { int index = to_sensor_dev_attr(devattr)->index; struct max1668_data *data = max1668_update_device(dev); if (IS_ERR(data)) return PTR_ERR(data); return sprintf(buf, "%d\n", data->temp_max[index] * 1000); } static ssize_t show_temp_min(struct device *dev, struct device_attribute *devattr, char *buf) { int index = to_sensor_dev_attr(devattr)->index; struct max1668_data *data = max1668_update_device(dev); if (IS_ERR(data)) return PTR_ERR(data); return sprintf(buf, "%d\n", data->temp_min[index] * 1000); } static ssize_t show_alarm(struct device *dev, struct device_attribute *attr, char *buf) { int index = to_sensor_dev_attr(attr)->index; struct max1668_data *data = max1668_update_device(dev); if (IS_ERR(data)) return PTR_ERR(data); return sprintf(buf, "%u\n", (data->alarms >> index) & 0x1); } static ssize_t show_fault(struct device *dev, struct device_attribute *devattr, char *buf) { int index = to_sensor_dev_attr(devattr)->index; struct max1668_data *data = max1668_update_device(dev); if (IS_ERR(data)) return PTR_ERR(data); return sprintf(buf, "%u\n", (data->alarms & (1 << 12)) && data->temp[index] == 127); } static ssize_t set_temp_max(struct device *dev, struct device_attribute *devattr, const char *buf, size_t count) { int index = to_sensor_dev_attr(devattr)->index; struct max1668_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; long temp; int ret; ret = kstrtol(buf, 10, &temp); if (ret < 0) return ret; mutex_lock(&data->update_lock); data->temp_max[index] = clamp_val(temp/1000, -128, 127); ret = i2c_smbus_write_byte_data(client, MAX1668_REG_LIMH_WR(index), data->temp_max[index]); if (ret < 0) count = ret; mutex_unlock(&data->update_lock); return count; } static ssize_t set_temp_min(struct device *dev, struct device_attribute *devattr, const char *buf, size_t count) { int index = to_sensor_dev_attr(devattr)->index; struct max1668_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; long temp; int ret; ret = kstrtol(buf, 10, &temp); if (ret < 0) return ret; mutex_lock(&data->update_lock); data->temp_min[index] = clamp_val(temp/1000, -128, 127); ret = i2c_smbus_write_byte_data(client, MAX1668_REG_LIML_WR(index), data->temp_min[index]); if (ret < 0) count = ret; mutex_unlock(&data->update_lock); return count; } static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0); static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp_max, set_temp_max, 0); static SENSOR_DEVICE_ATTR(temp1_min, S_IRUGO, show_temp_min, set_temp_min, 0); static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1); static SENSOR_DEVICE_ATTR(temp2_max, S_IRUGO, show_temp_max, set_temp_max, 1); static SENSOR_DEVICE_ATTR(temp2_min, S_IRUGO, show_temp_min, set_temp_min, 1); static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 2); static SENSOR_DEVICE_ATTR(temp3_max, S_IRUGO, show_temp_max, set_temp_max, 2); static SENSOR_DEVICE_ATTR(temp3_min, S_IRUGO, show_temp_min, set_temp_min, 2); static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp, NULL, 3); static SENSOR_DEVICE_ATTR(temp4_max, S_IRUGO, show_temp_max, set_temp_max, 3); static SENSOR_DEVICE_ATTR(temp4_min, S_IRUGO, show_temp_min, set_temp_min, 3); static SENSOR_DEVICE_ATTR(temp5_input, S_IRUGO, show_temp, NULL, 4); static SENSOR_DEVICE_ATTR(temp5_max, S_IRUGO, show_temp_max, set_temp_max, 4); static SENSOR_DEVICE_ATTR(temp5_min, S_IRUGO, show_temp_min, set_temp_min, 4); static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 14); static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 13); static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_alarm, NULL, 7); static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 6); static SENSOR_DEVICE_ATTR(temp3_min_alarm, S_IRUGO, show_alarm, NULL, 5); static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_alarm, NULL, 4); static SENSOR_DEVICE_ATTR(temp4_min_alarm, S_IRUGO, show_alarm, NULL, 3); static SENSOR_DEVICE_ATTR(temp4_max_alarm, S_IRUGO, show_alarm, NULL, 2); static SENSOR_DEVICE_ATTR(temp5_min_alarm, S_IRUGO, show_alarm, NULL, 1); static SENSOR_DEVICE_ATTR(temp5_max_alarm, S_IRUGO, show_alarm, NULL, 0); static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_fault, NULL, 1); static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_fault, NULL, 2); static SENSOR_DEVICE_ATTR(temp4_fault, S_IRUGO, show_fault, NULL, 3); static SENSOR_DEVICE_ATTR(temp5_fault, S_IRUGO, show_fault, NULL, 4); /* Attributes common to MAX1668, MAX1989 and MAX1805 */ static struct attribute *max1668_attribute_common[] = { &sensor_dev_attr_temp1_max.dev_attr.attr, &sensor_dev_attr_temp1_min.dev_attr.attr, &sensor_dev_attr_temp1_input.dev_attr.attr, &sensor_dev_attr_temp2_max.dev_attr.attr, &sensor_dev_attr_temp2_min.dev_attr.attr, &sensor_dev_attr_temp2_input.dev_attr.attr, &sensor_dev_attr_temp3_max.dev_attr.attr, &sensor_dev_attr_temp3_min.dev_attr.attr, &sensor_dev_attr_temp3_input.dev_attr.attr, &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, &sensor_dev_attr_temp2_max_alarm.dev_attr.attr, &sensor_dev_attr_temp2_min_alarm.dev_attr.attr, &sensor_dev_attr_temp3_max_alarm.dev_attr.attr, &sensor_dev_attr_temp3_min_alarm.dev_attr.attr, &sensor_dev_attr_temp2_fault.dev_attr.attr, &sensor_dev_attr_temp3_fault.dev_attr.attr, NULL }; /* Attributes not present on MAX1805 */ static struct attribute *max1668_attribute_unique[] = { &sensor_dev_attr_temp4_max.dev_attr.attr, &sensor_dev_attr_temp4_min.dev_attr.attr, &sensor_dev_attr_temp4_input.dev_attr.attr, &sensor_dev_attr_temp5_max.dev_attr.attr, &sensor_dev_attr_temp5_min.dev_attr.attr, &sensor_dev_attr_temp5_input.dev_attr.attr, &sensor_dev_attr_temp4_max_alarm.dev_attr.attr, &sensor_dev_attr_temp4_min_alarm.dev_attr.attr, &sensor_dev_attr_temp5_max_alarm.dev_attr.attr, &sensor_dev_attr_temp5_min_alarm.dev_attr.attr, &sensor_dev_attr_temp4_fault.dev_attr.attr, &sensor_dev_attr_temp5_fault.dev_attr.attr, NULL }; static umode_t max1668_attribute_mode(struct kobject *kobj, struct attribute *attr, int index) { umode_t ret = S_IRUGO; if (read_only) return ret; if (attr == &sensor_dev_attr_temp1_max.dev_attr.attr || attr == &sensor_dev_attr_temp2_max.dev_attr.attr || attr == &sensor_dev_attr_temp3_max.dev_attr.attr || attr == &sensor_dev_attr_temp4_max.dev_attr.attr || attr == &sensor_dev_attr_temp5_max.dev_attr.attr || attr == &sensor_dev_attr_temp1_min.dev_attr.attr || attr == &sensor_dev_attr_temp2_min.dev_attr.attr || attr == &sensor_dev_attr_temp3_min.dev_attr.attr || attr == &sensor_dev_attr_temp4_min.dev_attr.attr || attr == &sensor_dev_attr_temp5_min.dev_attr.attr) ret |= S_IWUSR; return ret; } static const struct attribute_group max1668_group_common = { .attrs = max1668_attribute_common, .is_visible = max1668_attribute_mode }; static const struct attribute_group max1668_group_unique = { .attrs = max1668_attribute_unique, .is_visible = max1668_attribute_mode }; /* Return 0 if detection is successful, -ENODEV otherwise */ static int max1668_detect(struct i2c_client *client, struct i2c_board_info *info) { struct i2c_adapter *adapter = client->adapter; const char *type_name; int man_id, dev_id; if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) return -ENODEV; /* Check for unsupported part */ man_id = i2c_smbus_read_byte_data(client, MAX1668_REG_MAN_ID); if (man_id != MAN_ID_MAXIM) return -ENODEV; dev_id = i2c_smbus_read_byte_data(client, MAX1668_REG_DEV_ID); if (dev_id < 0) return -ENODEV; type_name = NULL; if (dev_id == DEV_ID_MAX1668) type_name = "max1668"; else if (dev_id == DEV_ID_MAX1805) type_name = "max1805"; else if (dev_id == DEV_ID_MAX1989) type_name = "max1989"; if (!type_name) return -ENODEV; strlcpy(info->type, type_name, I2C_NAME_SIZE); return 0; } static int max1668_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct i2c_adapter *adapter = client->adapter; struct device *dev = &client->dev; struct device *hwmon_dev; struct max1668_data *data; if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) return -ENODEV; data = devm_kzalloc(dev, sizeof(struct max1668_data), GFP_KERNEL); if (!data) return -ENOMEM; data->client = client; data->type = id->driver_data; mutex_init(&data->update_lock); /* sysfs hooks */ data->groups[0] = &max1668_group_common; if (data->type == max1668 || data->type == max1989) data->groups[1] = &max1668_group_unique; hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, data, data->groups); return PTR_ERR_OR_ZERO(hwmon_dev); } static const struct i2c_device_id max1668_id[] = { { "max1668", max1668 }, { "max1805", max1805 }, { "max1989", max1989 }, { } }; MODULE_DEVICE_TABLE(i2c, max1668_id); /* This is the driver that will be inserted */ static struct i2c_driver max1668_driver = { .class = I2C_CLASS_HWMON, .driver = { .name = "max1668", }, .probe = max1668_probe, .id_table = max1668_id, .detect = max1668_detect, .address_list = max1668_addr_list, }; module_i2c_driver(max1668_driver); MODULE_AUTHOR("David George <david.george@ska.ac.za>"); MODULE_DESCRIPTION("MAX1668 remote temperature sensor driver"); MODULE_LICENSE("GPL");