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linux/drivers/hwmon/max1619.c
Guenter Roeck 90368fa397 hwmon: (max1619) Improve chip detection code 
Bail out immediately if reading any of the registers used for chip
detection fails, or if it returns an unexpected value. Drop all log
messages from detection code.

Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2024-07-31 10:43:53 -07:00

400 lines
9.3 KiB
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* max1619.c - Part of lm_sensors, Linux kernel modules for hardware
* monitoring
* Copyright (C) 2003-2004 Oleksij Rempel <bug-track@fisher-privat.net>
* Jean Delvare <jdelvare@suse.de>
*
* Based on the lm90 driver. The MAX1619 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://pdfserv.maxim-ic.com/en/ds/MAX1619.pdf
*/
#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/util_macros.h>
static const unsigned short normal_i2c[] = {
0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
#define MAX1619_REG_LOCAL_TEMP 0x00
#define MAX1619_REG_REMOTE_TEMP 0x01
#define MAX1619_REG_STATUS 0x02
#define MAX1619_REG_CONFIG 0x03
#define MAX1619_REG_CONVRATE 0x04
#define MAX1619_REG_REMOTE_HIGH 0x07
#define MAX1619_REG_REMOTE_LOW 0x08
#define MAX1619_REG_REMOTE_CRIT 0x10
#define MAX1619_REG_REMOTE_CRIT_HYST 0x11
#define MAX1619_REG_MAN_ID 0xFE
#define MAX1619_REG_CHIP_ID 0xFF
static int get_alarms(struct regmap *regmap)
{
static u32 regs[2] = { MAX1619_REG_STATUS, MAX1619_REG_CONFIG };
u8 regdata[2];
int ret;
ret = regmap_multi_reg_read(regmap, regs, regdata, 2);
if (ret)
return ret;
/* OVERT status bit may be reversed */
if (!(regdata[1] & 0x20))
regdata[0] ^= 0x02;
return regdata[0] & 0x1e;
}
static int max1619_temp_read(struct regmap *regmap, u32 attr, int channel, long *val)
{
int reg = -1, alarm_bit = 0;
u32 temp;
int ret;
switch (attr) {
case hwmon_temp_input:
reg = channel ? MAX1619_REG_REMOTE_TEMP : MAX1619_REG_LOCAL_TEMP;
break;
case hwmon_temp_min:
reg = MAX1619_REG_REMOTE_LOW;
break;
case hwmon_temp_max:
reg = MAX1619_REG_REMOTE_HIGH;
break;
case hwmon_temp_crit:
reg = MAX1619_REG_REMOTE_CRIT;
break;
case hwmon_temp_crit_hyst:
reg = MAX1619_REG_REMOTE_CRIT_HYST;
break;
case hwmon_temp_min_alarm:
alarm_bit = 3;
break;
case hwmon_temp_max_alarm:
alarm_bit = 4;
break;
case hwmon_temp_crit_alarm:
alarm_bit = 1;
break;
case hwmon_temp_fault:
alarm_bit = 2;
break;
default:
return -EOPNOTSUPP;
}
if (reg >= 0) {
ret = regmap_read(regmap, reg, &temp);
if (ret < 0)
return ret;
*val = sign_extend32(temp, 7) * 1000;
} else {
ret = get_alarms(regmap);
if (ret < 0)
return ret;
*val = !!(ret & BIT(alarm_bit));
}
return 0;
}
static u16 update_intervals[] = { 16000, 8000, 4000, 2000, 1000, 500, 250, 125 };
static int max1619_chip_read(struct regmap *regmap, u32 attr, long *val)
{
int alarms, ret;
u32 regval;
switch (attr) {
case hwmon_chip_update_interval:
ret = regmap_read(regmap, MAX1619_REG_CONVRATE, &regval);
if (ret < 0)
return ret;
*val = update_intervals[regval & 7];
break;
case hwmon_chip_alarms:
alarms = get_alarms(regmap);
if (alarms < 0)
return alarms;
*val = alarms;
break;
default:
return -EOPNOTSUPP;
}
return 0;
}
static int max1619_read(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long *val)
{
struct regmap *regmap = dev_get_drvdata(dev);
switch (type) {
case hwmon_chip:
return max1619_chip_read(regmap, attr, val);
case hwmon_temp:
return max1619_temp_read(regmap, attr, channel, val);
default:
return -EOPNOTSUPP;
}
}
static int max1619_chip_write(struct regmap *regmap, u32 attr, long val)
{
switch (attr) {
case hwmon_chip_update_interval:
val = find_closest_descending(val, update_intervals, ARRAY_SIZE(update_intervals));
return regmap_write(regmap, MAX1619_REG_CONVRATE, val);
default:
return -EOPNOTSUPP;
}
}
static int max1619_temp_write(struct regmap *regmap,
u32 attr, int channel, long val)
{
int reg;
switch (attr) {
case hwmon_temp_min:
reg = MAX1619_REG_REMOTE_LOW;
break;
case hwmon_temp_max:
reg = MAX1619_REG_REMOTE_HIGH;
break;
case hwmon_temp_crit:
reg = MAX1619_REG_REMOTE_CRIT;
break;
case hwmon_temp_crit_hyst:
reg = MAX1619_REG_REMOTE_CRIT_HYST;
break;
default:
return -EOPNOTSUPP;
}
val = DIV_ROUND_CLOSEST(clamp_val(val, -128000, 127000), 1000);
return regmap_write(regmap, reg, val);
}
static int max1619_write(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long val)
{
struct regmap *regmap = dev_get_drvdata(dev);
switch (type) {
case hwmon_chip:
return max1619_chip_write(regmap, attr, val);
case hwmon_temp:
return max1619_temp_write(regmap, attr, channel, val);
default:
return -EOPNOTSUPP;
}
}
static umode_t max1619_is_visible(const void *_data, enum hwmon_sensor_types type,
u32 attr, int channel)
{
switch (type) {
case hwmon_chip:
switch (attr) {
case hwmon_chip_update_interval:
return 0644;
case hwmon_chip_alarms:
return 0444;
default:
break;
}
break;
case hwmon_temp:
switch (attr) {
case hwmon_temp_input:
return 0444;
case hwmon_temp_min:
case hwmon_temp_max:
case hwmon_temp_crit:
case hwmon_temp_crit_hyst:
return 0644;
case hwmon_temp_min_alarm:
case hwmon_temp_max_alarm:
case hwmon_temp_crit_alarm:
case hwmon_temp_fault:
return 0444;
default:
break;
}
break;
default:
break;
}
return 0;
}
static const struct hwmon_channel_info * const max1619_info[] = {
HWMON_CHANNEL_INFO(chip, HWMON_C_ALARMS | HWMON_C_UPDATE_INTERVAL),
HWMON_CHANNEL_INFO(temp,
HWMON_T_INPUT,
HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
HWMON_T_CRIT | HWMON_T_CRIT_HYST |
HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM |
HWMON_T_CRIT_ALARM | HWMON_T_FAULT),
NULL
};
static const struct hwmon_ops max1619_hwmon_ops = {
.is_visible = max1619_is_visible,
.read = max1619_read,
.write = max1619_write,
};
static const struct hwmon_chip_info max1619_chip_info = {
.ops = &max1619_hwmon_ops,
.info = max1619_info,
};
/* Return 0 if detection is successful, -ENODEV otherwise */
static int max1619_detect(struct i2c_client *client,
struct i2c_board_info *info)
{
struct i2c_adapter *adapter = client->adapter;
int regval;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
return -ENODEV;
regval = i2c_smbus_read_byte_data(client, MAX1619_REG_CONFIG);
if (regval < 0 || (regval & 0x03))
return -ENODEV;
regval = i2c_smbus_read_byte_data(client, MAX1619_REG_CONVRATE);
if (regval < 0 || regval > 0x07)
return -ENODEV;
regval = i2c_smbus_read_byte_data(client, MAX1619_REG_STATUS);
if (regval < 0 || (regval & 0x61))
return -ENODEV;
regval = i2c_smbus_read_byte_data(client, MAX1619_REG_MAN_ID);
if (regval != 0x4d)
return -ENODEV;
regval = i2c_smbus_read_byte_data(client, MAX1619_REG_CHIP_ID);
if (regval != 0x04)
return -ENODEV;
strscpy(info->type, "max1619", I2C_NAME_SIZE);
return 0;
}
static int max1619_init_chip(struct regmap *regmap)
{
int ret;
ret = regmap_write(regmap, MAX1619_REG_CONVRATE, 5); /* 2 Hz */
if (ret)
return ret;
/* Start conversions */
return regmap_clear_bits(regmap, MAX1619_REG_CONFIG, 0x40);
}
/* regmap */
static int max1619_reg_read(void *context, unsigned int reg, unsigned int *val)
{
int ret;
ret = i2c_smbus_read_byte_data(context, reg);
if (ret < 0)
return ret;
*val = ret;
return 0;
}
static int max1619_reg_write(void *context, unsigned int reg, unsigned int val)
{
int offset = reg < MAX1619_REG_REMOTE_CRIT ? 6 : 2;
return i2c_smbus_write_byte_data(context, reg + offset, val);
}
static bool max1619_regmap_is_volatile(struct device *dev, unsigned int reg)
{
return reg <= MAX1619_REG_STATUS;
}
static bool max1619_regmap_is_writeable(struct device *dev, unsigned int reg)
{
return reg > MAX1619_REG_STATUS && reg <= MAX1619_REG_REMOTE_CRIT_HYST;
}
static const struct regmap_config max1619_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = MAX1619_REG_REMOTE_CRIT_HYST,
.cache_type = REGCACHE_MAPLE,
.volatile_reg = max1619_regmap_is_volatile,
.writeable_reg = max1619_regmap_is_writeable,
};
static const struct regmap_bus max1619_regmap_bus = {
.reg_write = max1619_reg_write,
.reg_read = max1619_reg_read,
};
static int max1619_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
struct device *hwmon_dev;
struct regmap *regmap;
int ret;
regmap = devm_regmap_init(dev, &max1619_regmap_bus, client,
&max1619_regmap_config);
if (IS_ERR(regmap))
return PTR_ERR(regmap);
ret = max1619_init_chip(regmap);
if (ret)
return ret;
hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
regmap, &max1619_chip_info, NULL);
return PTR_ERR_OR_ZERO(hwmon_dev);
}
static const struct i2c_device_id max1619_id[] = {
{ "max1619" },
{ }
};
MODULE_DEVICE_TABLE(i2c, max1619_id);
#ifdef CONFIG_OF
static const struct of_device_id max1619_of_match[] = {
{ .compatible = "maxim,max1619", },
{},
};
MODULE_DEVICE_TABLE(of, max1619_of_match);
#endif
static struct i2c_driver max1619_driver = {
.class = I2C_CLASS_HWMON,
.driver = {
.name = "max1619",
.of_match_table = of_match_ptr(max1619_of_match),
},
.probe = max1619_probe,
.id_table = max1619_id,
.detect = max1619_detect,
.address_list = normal_i2c,
};
module_i2c_driver(max1619_driver);
MODULE_AUTHOR("Oleksij Rempel <bug-track@fisher-privat.net>, Jean Delvare <jdelvare@suse.de>");
MODULE_DESCRIPTION("MAX1619 sensor driver");
MODULE_LICENSE("GPL");
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