// SPDX-License-Identifier: GPL-2.0-or-later /* * lm92 - Hardware monitoring driver * Copyright (C) 2005-2008 Jean Delvare <[email protected]> * * Based on the lm90 driver, with some ideas taken from the lm_sensors * lm92 driver as well. * * The LM92 is a sensor chip made by National Semiconductor. It reports * its own temperature with a 0.0625 deg resolution and a 0.33 deg * accuracy. Complete datasheet can be obtained from National's website * at: * http://www.national.com/pf/LM/LM92.html * * This driver also supports the MAX6635 sensor chip made by Maxim. * This chip is compatible with the LM92, but has a lesser accuracy * (1.0 deg). Complete datasheet can be obtained from Maxim's website * at: * http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3074 * * Since the LM92 was the first chipset supported by this driver, most * comments will refer to this chipset, but are actually general and * concern all supported chipsets, unless mentioned otherwise. * * Support could easily be added for the National Semiconductor LM76 * and Maxim MAX6633 and MAX6634 chips, which are mostly compatible * with the LM92. */ #include <linux/module.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/i2c.h> #include <linux/hwmon.h> #include <linux/hwmon-sysfs.h> #include <linux/err.h> #include <linux/mutex.h> #include <linux/jiffies.h> /* * The LM92 and MAX6635 have 2 two-state pins for address selection, * resulting in 4 possible addresses. */ static const unsigned short normal_i2c[] = …; enum chips { … }; /* The LM92 registers */ #define LM92_REG_CONFIG … #define LM92_REG_TEMP … #define LM92_REG_TEMP_HYST … #define LM92_REG_TEMP_CRIT … #define LM92_REG_TEMP_LOW … #define LM92_REG_TEMP_HIGH … #define LM92_REG_MAN_ID … /* * The LM92 uses signed 13-bit values with LSB = 0.0625 degree Celsius, * left-justified in 16-bit registers. No rounding is done, with such * a resolution it's just not worth it. Note that the MAX6635 doesn't * make use of the 4 lower bits for limits (i.e. effective resolution * for limits is 1 degree Celsius). */ static inline int TEMP_FROM_REG(s16 reg) { … } static inline s16 TEMP_TO_REG(long val) { … } /* Alarm flags are stored in the 3 LSB of the temperature register */ static inline u8 ALARMS_FROM_REG(s16 reg) { … } enum temp_index { … }; static const u8 regs[t_num_regs] = …; /* Client data (each client gets its own) */ struct lm92_data { … }; /* * Sysfs attributes and callback functions */ static struct lm92_data *lm92_update_device(struct device *dev) { … } static ssize_t temp_show(struct device *dev, struct device_attribute *devattr, char *buf) { … } static ssize_t temp_store(struct device *dev, struct device_attribute *devattr, const char *buf, size_t count) { … } static ssize_t temp_hyst_show(struct device *dev, struct device_attribute *devattr, char *buf) { … } static ssize_t temp1_min_hyst_show(struct device *dev, struct device_attribute *attr, char *buf) { … } static ssize_t temp_hyst_store(struct device *dev, struct device_attribute *devattr, const char *buf, size_t count) { … } static ssize_t alarms_show(struct device *dev, struct device_attribute *attr, char *buf) { … } static ssize_t alarm_show(struct device *dev, struct device_attribute *attr, char *buf) { … } static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, t_input); static SENSOR_DEVICE_ATTR_RW(temp1_crit, temp, t_crit); static SENSOR_DEVICE_ATTR_RW(temp1_crit_hyst, temp_hyst, t_crit); static SENSOR_DEVICE_ATTR_RW(temp1_min, temp, t_min); static DEVICE_ATTR_RO(temp1_min_hyst); static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, t_max); static SENSOR_DEVICE_ATTR_RO(temp1_max_hyst, temp_hyst, t_max); static DEVICE_ATTR_RO(alarms); static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, alarm, 2); static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, alarm, 0); static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 1); /* * Detection and registration */ static void lm92_init_client(struct i2c_client *client) { … } static struct attribute *lm92_attrs[] = …; ATTRIBUTE_GROUPS(…); /* Return 0 if detection is successful, -ENODEV otherwise */ static int lm92_detect(struct i2c_client *new_client, struct i2c_board_info *info) { … } static int lm92_probe(struct i2c_client *new_client) { … } /* * Module and driver stuff */ static const struct i2c_device_id lm92_id[] = …; MODULE_DEVICE_TABLE(i2c, lm92_id); static struct i2c_driver lm92_driver = …; module_i2c_driver(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …;
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