linux/drivers/hwmon/lm77.c
Stephen Kitt 6748703856 hwmon: use simple i2c probe function
Many hwmon drivers don't use the id information provided by the old
i2c probe function, and the remainder can easily be adapted to the new
form ("probe_new") by calling i2c_match_id explicitly.

This avoids scanning the identifier tables during probes.

Drivers which didn't use the id are converted as-is; drivers which did
are modified as follows:

* if the information in i2c_client is sufficient, that's used instead
  (client->name);
* anything else is handled by calling i2c_match_id() with the same
  level of error-handling (if any) as before.

A few drivers aren't included in this patch because they have a
different set of maintainers. They will be covered by other patches.

Signed-off-by: Stephen Kitt <steve@sk2.org>
Link: https://lore.kernel.org/r/20200813160222.1503401-1-steve@sk2.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2020-09-23 09:42:39 -07:00

362 lines
9.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* lm77.c - Part of lm_sensors, Linux kernel modules for hardware
* monitoring
*
* Copyright (c) 2004 Andras BALI <drewie@freemail.hu>
*
* Heavily based on lm75.c by Frodo Looijaard <frodol@dds.nl>. The LM77
* is a temperature sensor and thermal window comparator with 0.5 deg
* resolution made by National Semiconductor. Complete datasheet can be
* obtained at their site:
* http://www.national.com/pf/LM/LM77.html
*/
#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 normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
I2C_CLIENT_END };
/* The LM77 registers */
#define LM77_REG_TEMP 0x00
#define LM77_REG_CONF 0x01
#define LM77_REG_TEMP_HYST 0x02
#define LM77_REG_TEMP_CRIT 0x03
#define LM77_REG_TEMP_MIN 0x04
#define LM77_REG_TEMP_MAX 0x05
enum temp_index {
t_input = 0,
t_crit,
t_min,
t_max,
t_hyst,
t_num_temp
};
static const u8 temp_regs[t_num_temp] = {
[t_input] = LM77_REG_TEMP,
[t_min] = LM77_REG_TEMP_MIN,
[t_max] = LM77_REG_TEMP_MAX,
[t_crit] = LM77_REG_TEMP_CRIT,
[t_hyst] = LM77_REG_TEMP_HYST,
};
/* Each client has this additional data */
struct lm77_data {
struct i2c_client *client;
struct mutex update_lock;
char valid;
unsigned long last_updated; /* In jiffies */
int temp[t_num_temp]; /* index using temp_index */
u8 alarms;
};
/* straight from the datasheet */
#define LM77_TEMP_MIN (-55000)
#define LM77_TEMP_MAX 125000
/*
* In the temperature registers, the low 3 bits are not part of the
* temperature values; they are the status bits.
*/
static inline s16 LM77_TEMP_TO_REG(int temp)
{
return (temp / 500) * 8;
}
static inline int LM77_TEMP_FROM_REG(s16 reg)
{
return (reg / 8) * 500;
}
/*
* All registers are word-sized, except for the configuration register.
* The LM77 uses the high-byte first convention.
*/
static u16 lm77_read_value(struct i2c_client *client, u8 reg)
{
if (reg == LM77_REG_CONF)
return i2c_smbus_read_byte_data(client, reg);
else
return i2c_smbus_read_word_swapped(client, reg);
}
static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value)
{
if (reg == LM77_REG_CONF)
return i2c_smbus_write_byte_data(client, reg, value);
else
return i2c_smbus_write_word_swapped(client, reg, value);
}
static struct lm77_data *lm77_update_device(struct device *dev)
{
struct lm77_data *data = dev_get_drvdata(dev);
struct i2c_client *client = data->client;
int i;
mutex_lock(&data->update_lock);
if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
|| !data->valid) {
dev_dbg(&client->dev, "Starting lm77 update\n");
for (i = 0; i < t_num_temp; i++) {
data->temp[i] =
LM77_TEMP_FROM_REG(lm77_read_value(client,
temp_regs[i]));
}
data->alarms =
lm77_read_value(client, LM77_REG_TEMP) & 0x0007;
data->last_updated = jiffies;
data->valid = 1;
}
mutex_unlock(&data->update_lock);
return data;
}
/* sysfs stuff */
static ssize_t temp_show(struct device *dev, struct device_attribute *devattr,
char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
struct lm77_data *data = lm77_update_device(dev);
return sprintf(buf, "%d\n", data->temp[attr->index]);
}
static ssize_t temp_hyst_show(struct device *dev,
struct device_attribute *devattr, char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
struct lm77_data *data = lm77_update_device(dev);
int nr = attr->index;
int temp;
temp = nr == t_min ? data->temp[nr] + data->temp[t_hyst] :
data->temp[nr] - data->temp[t_hyst];
return sprintf(buf, "%d\n", temp);
}
static ssize_t temp_store(struct device *dev,
struct device_attribute *devattr, const char *buf,
size_t count)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
struct lm77_data *data = dev_get_drvdata(dev);
struct i2c_client *client = data->client;
int nr = attr->index;
long val;
int err;
err = kstrtol(buf, 10, &val);
if (err)
return err;
val = clamp_val(val, LM77_TEMP_MIN, LM77_TEMP_MAX);
mutex_lock(&data->update_lock);
data->temp[nr] = val;
lm77_write_value(client, temp_regs[nr], LM77_TEMP_TO_REG(val));
mutex_unlock(&data->update_lock);
return count;
}
/*
* hysteresis is stored as a relative value on the chip, so it has to be
* converted first.
*/
static ssize_t temp_hyst_store(struct device *dev,
struct device_attribute *devattr,
const char *buf, size_t count)
{
struct lm77_data *data = dev_get_drvdata(dev);
struct i2c_client *client = data->client;
long val;
int err;
err = kstrtol(buf, 10, &val);
if (err)
return err;
mutex_lock(&data->update_lock);
val = clamp_val(data->temp[t_crit] - val, LM77_TEMP_MIN, LM77_TEMP_MAX);
data->temp[t_hyst] = val;
lm77_write_value(client, LM77_REG_TEMP_HYST,
LM77_TEMP_TO_REG(data->temp[t_hyst]));
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 lm77_data *data = lm77_update_device(dev);
return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1);
}
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_min, temp, t_min);
static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, t_max);
static SENSOR_DEVICE_ATTR_RW(temp1_crit_hyst, temp_hyst, t_crit);
static SENSOR_DEVICE_ATTR_RO(temp1_min_hyst, temp_hyst, t_min);
static SENSOR_DEVICE_ATTR_RO(temp1_max_hyst, temp_hyst, t_max);
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);
static struct attribute *lm77_attrs[] = {
&sensor_dev_attr_temp1_input.dev_attr.attr,
&sensor_dev_attr_temp1_crit.dev_attr.attr,
&sensor_dev_attr_temp1_min.dev_attr.attr,
&sensor_dev_attr_temp1_max.dev_attr.attr,
&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
&sensor_dev_attr_temp1_min_hyst.dev_attr.attr,
&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
NULL
};
ATTRIBUTE_GROUPS(lm77);
/* Return 0 if detection is successful, -ENODEV otherwise */
static int lm77_detect(struct i2c_client *client, struct i2c_board_info *info)
{
struct i2c_adapter *adapter = client->adapter;
int i, cur, conf, hyst, crit, min, max;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_SMBUS_WORD_DATA))
return -ENODEV;
/*
* Here comes the remaining detection. Since the LM77 has no
* register dedicated to identification, we have to rely on the
* following tricks:
*
* 1. the high 4 bits represent the sign and thus they should
* always be the same
* 2. the high 3 bits are unused in the configuration register
* 3. addresses 0x06 and 0x07 return the last read value
* 4. registers cycling over 8-address boundaries
*
* Word-sized registers are high-byte first.
*/
/* addresses cycling */
cur = i2c_smbus_read_word_data(client, 0);
conf = i2c_smbus_read_byte_data(client, 1);
hyst = i2c_smbus_read_word_data(client, 2);
crit = i2c_smbus_read_word_data(client, 3);
min = i2c_smbus_read_word_data(client, 4);
max = i2c_smbus_read_word_data(client, 5);
for (i = 8; i <= 0xff; i += 8) {
if (i2c_smbus_read_byte_data(client, i + 1) != conf
|| i2c_smbus_read_word_data(client, i + 2) != hyst
|| i2c_smbus_read_word_data(client, i + 3) != crit
|| i2c_smbus_read_word_data(client, i + 4) != min
|| i2c_smbus_read_word_data(client, i + 5) != max)
return -ENODEV;
}
/* sign bits */
if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0)
|| ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0)
|| ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0)
|| ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0)
|| ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0))
return -ENODEV;
/* unused bits */
if (conf & 0xe0)
return -ENODEV;
/* 0x06 and 0x07 return the last read value */
cur = i2c_smbus_read_word_data(client, 0);
if (i2c_smbus_read_word_data(client, 6) != cur
|| i2c_smbus_read_word_data(client, 7) != cur)
return -ENODEV;
hyst = i2c_smbus_read_word_data(client, 2);
if (i2c_smbus_read_word_data(client, 6) != hyst
|| i2c_smbus_read_word_data(client, 7) != hyst)
return -ENODEV;
min = i2c_smbus_read_word_data(client, 4);
if (i2c_smbus_read_word_data(client, 6) != min
|| i2c_smbus_read_word_data(client, 7) != min)
return -ENODEV;
strlcpy(info->type, "lm77", I2C_NAME_SIZE);
return 0;
}
static void lm77_init_client(struct i2c_client *client)
{
/* Initialize the LM77 chip - turn off shutdown mode */
int conf = lm77_read_value(client, LM77_REG_CONF);
if (conf & 1)
lm77_write_value(client, LM77_REG_CONF, conf & 0xfe);
}
static int lm77_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
struct device *hwmon_dev;
struct lm77_data *data;
data = devm_kzalloc(dev, sizeof(struct lm77_data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->client = client;
mutex_init(&data->update_lock);
/* Initialize the LM77 chip */
lm77_init_client(client);
hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
data, lm77_groups);
return PTR_ERR_OR_ZERO(hwmon_dev);
}
static const struct i2c_device_id lm77_id[] = {
{ "lm77", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, lm77_id);
/* This is the driver that will be inserted */
static struct i2c_driver lm77_driver = {
.class = I2C_CLASS_HWMON,
.driver = {
.name = "lm77",
},
.probe_new = lm77_probe,
.id_table = lm77_id,
.detect = lm77_detect,
.address_list = normal_i2c,
};
module_i2c_driver(lm77_driver);
MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>");
MODULE_DESCRIPTION("LM77 driver");
MODULE_LICENSE("GPL");