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![Guenter Roeck](/assets/img/avatar_default.png)
Convert to use regmap. Leave caching to regmap and drop the register update function. While this can result in additional read operations if the temperature register is read continuously, it avoids re-reading the limit registers and thus overall reduces complexity. Signed-off-by: Guenter Roeck <linux@roeck-us.net>
526 lines
14 KiB
C
526 lines
14 KiB
C
/*
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* lm75.c - Part of lm_sensors, Linux kernel modules for hardware
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* monitoring
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* Copyright (c) 1998, 1999 Frodo Looijaard <frodol@dds.nl>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/jiffies.h>
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#include <linux/i2c.h>
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#include <linux/hwmon.h>
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#include <linux/hwmon-sysfs.h>
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#include <linux/err.h>
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#include <linux/of.h>
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#include <linux/regmap.h>
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#include <linux/thermal.h>
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#include "lm75.h"
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/*
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* This driver handles the LM75 and compatible digital temperature sensors.
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*/
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enum lm75_type { /* keep sorted in alphabetical order */
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adt75,
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ds1775,
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ds75,
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ds7505,
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g751,
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lm75,
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lm75a,
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lm75b,
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max6625,
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max6626,
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mcp980x,
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stds75,
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tcn75,
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tmp100,
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tmp101,
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tmp105,
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tmp112,
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tmp175,
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tmp275,
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tmp75,
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tmp75c,
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};
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/* Addresses scanned */
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static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
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0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
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/* The LM75 registers */
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#define LM75_REG_TEMP 0x00
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#define LM75_REG_CONF 0x01
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#define LM75_REG_HYST 0x02
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#define LM75_REG_MAX 0x03
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/* Each client has this additional data */
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struct lm75_data {
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struct i2c_client *client;
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struct regmap *regmap;
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u8 orig_conf;
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u8 resolution; /* In bits, between 9 and 12 */
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u8 resolution_limits;
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unsigned int sample_time; /* In ms */
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};
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/*-----------------------------------------------------------------------*/
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static inline long lm75_reg_to_mc(s16 temp, u8 resolution)
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{
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return ((temp >> (16 - resolution)) * 1000) >> (resolution - 8);
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}
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/* sysfs attributes for hwmon */
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static int lm75_read_temp(void *dev, int *temp)
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{
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struct lm75_data *data = dev_get_drvdata(dev);
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unsigned int _temp;
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int err;
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err = regmap_read(data->regmap, LM75_REG_TEMP, &_temp);
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if (err < 0)
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return err;
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*temp = lm75_reg_to_mc(_temp, data->resolution);
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return 0;
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}
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static ssize_t show_temp(struct device *dev, struct device_attribute *da,
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char *buf)
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{
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struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
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struct lm75_data *data = dev_get_drvdata(dev);
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unsigned int temp = 0;
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int err;
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err = regmap_read(data->regmap, attr->index, &temp);
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if (err < 0)
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return err;
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return sprintf(buf, "%ld\n", lm75_reg_to_mc(temp, data->resolution));
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}
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static ssize_t set_temp(struct device *dev, struct device_attribute *da,
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const char *buf, size_t count)
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{
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struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
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struct lm75_data *data = dev_get_drvdata(dev);
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long temp;
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int error;
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u8 resolution;
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error = kstrtol(buf, 10, &temp);
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if (error)
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return error;
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/*
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* Resolution of limit registers is assumed to be the same as the
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* temperature input register resolution unless given explicitly.
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*/
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if (attr->index && data->resolution_limits)
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resolution = data->resolution_limits;
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else
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resolution = data->resolution;
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temp = clamp_val(temp, LM75_TEMP_MIN, LM75_TEMP_MAX);
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temp = DIV_ROUND_CLOSEST(temp << (resolution - 8),
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1000) << (16 - resolution);
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error = regmap_write(data->regmap, attr->index, temp);
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if (error < 0)
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return error;
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return count;
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}
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static ssize_t show_update_interval(struct device *dev,
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struct device_attribute *da, char *buf)
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{
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struct lm75_data *data = dev_get_drvdata(dev);
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return sprintf(buf, "%u\n", data->sample_time);
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}
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static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
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show_temp, set_temp, LM75_REG_MAX);
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static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
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show_temp, set_temp, LM75_REG_HYST);
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static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, LM75_REG_TEMP);
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static DEVICE_ATTR(update_interval, S_IRUGO, show_update_interval, NULL);
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static struct attribute *lm75_attrs[] = {
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&sensor_dev_attr_temp1_input.dev_attr.attr,
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&sensor_dev_attr_temp1_max.dev_attr.attr,
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&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
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&dev_attr_update_interval.attr,
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NULL
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};
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ATTRIBUTE_GROUPS(lm75);
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static const struct thermal_zone_of_device_ops lm75_of_thermal_ops = {
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.get_temp = lm75_read_temp,
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};
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/*-----------------------------------------------------------------------*/
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/* device probe and removal */
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static bool lm75_is_writeable_reg(struct device *dev, unsigned int reg)
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{
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return reg != LM75_REG_TEMP;
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}
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static bool lm75_is_volatile_reg(struct device *dev, unsigned int reg)
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{
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return reg == LM75_REG_TEMP;
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}
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static const struct regmap_config lm75_regmap_config = {
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.reg_bits = 8,
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.val_bits = 16,
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.max_register = LM75_REG_MAX,
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.writeable_reg = lm75_is_writeable_reg,
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.volatile_reg = lm75_is_volatile_reg,
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.val_format_endian = REGMAP_ENDIAN_BIG,
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.cache_type = REGCACHE_RBTREE,
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.use_single_rw = true,
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};
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static void lm75_remove(void *data)
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{
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struct lm75_data *lm75 = data;
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struct i2c_client *client = lm75->client;
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i2c_smbus_write_byte_data(client, LM75_REG_CONF, lm75->orig_conf);
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}
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static int
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lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
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{
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struct device *dev = &client->dev;
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struct device *hwmon_dev;
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struct lm75_data *data;
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int status;
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u8 set_mask, clr_mask;
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int new;
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enum lm75_type kind = id->driver_data;
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if (!i2c_check_functionality(client->adapter,
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I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
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return -EIO;
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data = devm_kzalloc(dev, sizeof(struct lm75_data), GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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data->client = client;
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data->regmap = devm_regmap_init_i2c(client, &lm75_regmap_config);
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if (IS_ERR(data->regmap))
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return PTR_ERR(data->regmap);
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/* Set to LM75 resolution (9 bits, 1/2 degree C) and range.
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* Then tweak to be more precise when appropriate.
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*/
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set_mask = 0;
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clr_mask = LM75_SHUTDOWN; /* continuous conversions */
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switch (kind) {
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case adt75:
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clr_mask |= 1 << 5; /* not one-shot mode */
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data->resolution = 12;
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data->sample_time = MSEC_PER_SEC / 8;
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break;
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case ds1775:
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case ds75:
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case stds75:
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clr_mask |= 3 << 5;
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set_mask |= 2 << 5; /* 11-bit mode */
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data->resolution = 11;
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data->sample_time = MSEC_PER_SEC;
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break;
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case ds7505:
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set_mask |= 3 << 5; /* 12-bit mode */
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data->resolution = 12;
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data->sample_time = MSEC_PER_SEC / 4;
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break;
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case g751:
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case lm75:
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case lm75a:
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data->resolution = 9;
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data->sample_time = MSEC_PER_SEC / 2;
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break;
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case lm75b:
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data->resolution = 11;
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data->sample_time = MSEC_PER_SEC / 4;
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break;
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case max6625:
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data->resolution = 9;
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data->sample_time = MSEC_PER_SEC / 4;
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break;
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case max6626:
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data->resolution = 12;
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data->resolution_limits = 9;
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data->sample_time = MSEC_PER_SEC / 4;
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break;
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case tcn75:
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data->resolution = 9;
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data->sample_time = MSEC_PER_SEC / 8;
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break;
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case mcp980x:
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data->resolution_limits = 9;
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/* fall through */
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case tmp100:
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case tmp101:
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set_mask |= 3 << 5; /* 12-bit mode */
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data->resolution = 12;
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data->sample_time = MSEC_PER_SEC;
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clr_mask |= 1 << 7; /* not one-shot mode */
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break;
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case tmp112:
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set_mask |= 3 << 5; /* 12-bit mode */
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clr_mask |= 1 << 7; /* not one-shot mode */
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data->resolution = 12;
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data->sample_time = MSEC_PER_SEC / 4;
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break;
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case tmp105:
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case tmp175:
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case tmp275:
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case tmp75:
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set_mask |= 3 << 5; /* 12-bit mode */
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clr_mask |= 1 << 7; /* not one-shot mode */
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data->resolution = 12;
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data->sample_time = MSEC_PER_SEC / 2;
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break;
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case tmp75c:
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clr_mask |= 1 << 5; /* not one-shot mode */
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data->resolution = 12;
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data->sample_time = MSEC_PER_SEC / 4;
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break;
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}
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/* configure as specified */
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status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
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if (status < 0) {
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dev_dbg(dev, "Can't read config? %d\n", status);
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return status;
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}
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data->orig_conf = status;
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new = status & ~clr_mask;
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new |= set_mask;
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if (status != new)
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i2c_smbus_write_byte_data(client, LM75_REG_CONF, new);
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devm_add_action(dev, lm75_remove, data);
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dev_dbg(dev, "Config %02x\n", new);
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hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
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data, lm75_groups);
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if (IS_ERR(hwmon_dev))
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return PTR_ERR(hwmon_dev);
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devm_thermal_zone_of_sensor_register(hwmon_dev, 0,
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hwmon_dev,
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&lm75_of_thermal_ops);
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dev_info(dev, "%s: sensor '%s'\n", dev_name(hwmon_dev), client->name);
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return 0;
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}
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static const struct i2c_device_id lm75_ids[] = {
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{ "adt75", adt75, },
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{ "ds1775", ds1775, },
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{ "ds75", ds75, },
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{ "ds7505", ds7505, },
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{ "g751", g751, },
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{ "lm75", lm75, },
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{ "lm75a", lm75a, },
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{ "lm75b", lm75b, },
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{ "max6625", max6625, },
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{ "max6626", max6626, },
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{ "mcp980x", mcp980x, },
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{ "stds75", stds75, },
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{ "tcn75", tcn75, },
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{ "tmp100", tmp100, },
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{ "tmp101", tmp101, },
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{ "tmp105", tmp105, },
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{ "tmp112", tmp112, },
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{ "tmp175", tmp175, },
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{ "tmp275", tmp275, },
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{ "tmp75", tmp75, },
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{ "tmp75c", tmp75c, },
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{ /* LIST END */ }
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};
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MODULE_DEVICE_TABLE(i2c, lm75_ids);
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#define LM75A_ID 0xA1
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/* Return 0 if detection is successful, -ENODEV otherwise */
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static int lm75_detect(struct i2c_client *new_client,
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struct i2c_board_info *info)
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{
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struct i2c_adapter *adapter = new_client->adapter;
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int i;
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int conf, hyst, os;
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bool is_lm75a = 0;
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if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
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I2C_FUNC_SMBUS_WORD_DATA))
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return -ENODEV;
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/*
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* Now, we do the remaining detection. There is no identification-
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* dedicated register so we have to rely on several tricks:
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* unused bits, registers cycling over 8-address boundaries,
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* addresses 0x04-0x07 returning the last read value.
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* The cycling+unused addresses combination is not tested,
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* since it would significantly slow the detection down and would
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* hardly add any value.
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*
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* The National Semiconductor LM75A is different than earlier
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* LM75s. It has an ID byte of 0xaX (where X is the chip
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* revision, with 1 being the only revision in existence) in
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* register 7, and unused registers return 0xff rather than the
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* last read value.
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*
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* Note that this function only detects the original National
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* Semiconductor LM75 and the LM75A. Clones from other vendors
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* aren't detected, on purpose, because they are typically never
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* found on PC hardware. They are found on embedded designs where
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* they can be instantiated explicitly so detection is not needed.
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* The absence of identification registers on all these clones
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* would make their exhaustive detection very difficult and weak,
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* and odds are that the driver would bind to unsupported devices.
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*/
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/* Unused bits */
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conf = i2c_smbus_read_byte_data(new_client, 1);
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if (conf & 0xe0)
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return -ENODEV;
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/* First check for LM75A */
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if (i2c_smbus_read_byte_data(new_client, 7) == LM75A_ID) {
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/* LM75A returns 0xff on unused registers so
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just to be sure we check for that too. */
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if (i2c_smbus_read_byte_data(new_client, 4) != 0xff
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|| i2c_smbus_read_byte_data(new_client, 5) != 0xff
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|| i2c_smbus_read_byte_data(new_client, 6) != 0xff)
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return -ENODEV;
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is_lm75a = 1;
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hyst = i2c_smbus_read_byte_data(new_client, 2);
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os = i2c_smbus_read_byte_data(new_client, 3);
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} else { /* Traditional style LM75 detection */
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/* Unused addresses */
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hyst = i2c_smbus_read_byte_data(new_client, 2);
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if (i2c_smbus_read_byte_data(new_client, 4) != hyst
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|| i2c_smbus_read_byte_data(new_client, 5) != hyst
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|| i2c_smbus_read_byte_data(new_client, 6) != hyst
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|| i2c_smbus_read_byte_data(new_client, 7) != hyst)
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return -ENODEV;
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os = i2c_smbus_read_byte_data(new_client, 3);
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if (i2c_smbus_read_byte_data(new_client, 4) != os
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|| i2c_smbus_read_byte_data(new_client, 5) != os
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|| i2c_smbus_read_byte_data(new_client, 6) != os
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|| i2c_smbus_read_byte_data(new_client, 7) != os)
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return -ENODEV;
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}
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/*
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* It is very unlikely that this is a LM75 if both
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* hysteresis and temperature limit registers are 0.
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*/
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if (hyst == 0 && os == 0)
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return -ENODEV;
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/* Addresses cycling */
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for (i = 8; i <= 248; i += 40) {
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if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
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|| i2c_smbus_read_byte_data(new_client, i + 2) != hyst
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|| i2c_smbus_read_byte_data(new_client, i + 3) != os)
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return -ENODEV;
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if (is_lm75a && i2c_smbus_read_byte_data(new_client, i + 7)
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!= LM75A_ID)
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return -ENODEV;
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}
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strlcpy(info->type, is_lm75a ? "lm75a" : "lm75", I2C_NAME_SIZE);
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return 0;
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}
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#ifdef CONFIG_PM
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static int lm75_suspend(struct device *dev)
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{
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int status;
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struct i2c_client *client = to_i2c_client(dev);
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status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
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if (status < 0) {
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dev_dbg(&client->dev, "Can't read config? %d\n", status);
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return status;
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}
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status = status | LM75_SHUTDOWN;
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i2c_smbus_write_byte_data(client, LM75_REG_CONF, status);
|
|
return 0;
|
|
}
|
|
|
|
static int lm75_resume(struct device *dev)
|
|
{
|
|
int status;
|
|
struct i2c_client *client = to_i2c_client(dev);
|
|
status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
|
|
if (status < 0) {
|
|
dev_dbg(&client->dev, "Can't read config? %d\n", status);
|
|
return status;
|
|
}
|
|
status = status & ~LM75_SHUTDOWN;
|
|
i2c_smbus_write_byte_data(client, LM75_REG_CONF, status);
|
|
return 0;
|
|
}
|
|
|
|
static const struct dev_pm_ops lm75_dev_pm_ops = {
|
|
.suspend = lm75_suspend,
|
|
.resume = lm75_resume,
|
|
};
|
|
#define LM75_DEV_PM_OPS (&lm75_dev_pm_ops)
|
|
#else
|
|
#define LM75_DEV_PM_OPS NULL
|
|
#endif /* CONFIG_PM */
|
|
|
|
static struct i2c_driver lm75_driver = {
|
|
.class = I2C_CLASS_HWMON,
|
|
.driver = {
|
|
.name = "lm75",
|
|
.pm = LM75_DEV_PM_OPS,
|
|
},
|
|
.probe = lm75_probe,
|
|
.id_table = lm75_ids,
|
|
.detect = lm75_detect,
|
|
.address_list = normal_i2c,
|
|
};
|
|
|
|
module_i2c_driver(lm75_driver);
|
|
|
|
MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
|
|
MODULE_DESCRIPTION("LM75 driver");
|
|
MODULE_LICENSE("GPL");
|