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linux/drivers/hwmon/lm83.c
Krzysztof Kozlowski 3c370243cb hwmon: lm83: constify pointers to hwmon_channel_info 
Statically allocated array of pointed to hwmon_channel_info can be made
const for safety.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2023-04-19 07:08:36 -07:00

468 lines
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* lm83.c - Part of lm_sensors, Linux kernel modules for hardware
* monitoring
* Copyright (C) 2003-2009 Jean Delvare <jdelvare@suse.de>
*
* Heavily inspired from the lm78, lm75 and adm1021 drivers. The LM83 is
* a sensor chip made by National Semiconductor. It reports up to four
* temperatures (its own plus up to three external ones) with a 1 deg
* resolution and a 3-4 deg accuracy. Complete datasheet can be obtained
* from National's website at:
* http://www.national.com/pf/LM/LM83.html
* Since the datasheet omits to give the chip stepping code, I give it
* here: 0x03 (at register 0xff).
*
* Also supports the LM82 temp sensor, which is basically a stripped down
* model of the LM83. Datasheet is here:
* http://www.national.com/pf/LM/LM82.html
*/
#include <linux/bits.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/hwmon.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/slab.h>
/*
* Addresses to scan
* Address is selected using 2 three-level pins, resulting in 9 possible
* addresses.
*/
static const unsigned short normal_i2c[] = {
0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
enum chips { lm83, lm82 };
/*
* The LM83 registers
* Manufacturer ID is 0x01 for National Semiconductor.
*/
#define LM83_REG_R_MAN_ID 0xFE
#define LM83_REG_R_CHIP_ID 0xFF
#define LM83_REG_R_CONFIG 0x03
#define LM83_REG_W_CONFIG 0x09
#define LM83_REG_R_STATUS1 0x02
#define LM83_REG_R_STATUS2 0x35
#define LM83_REG_R_LOCAL_TEMP 0x00
#define LM83_REG_R_LOCAL_HIGH 0x05
#define LM83_REG_W_LOCAL_HIGH 0x0B
#define LM83_REG_R_REMOTE1_TEMP 0x30
#define LM83_REG_R_REMOTE1_HIGH 0x38
#define LM83_REG_W_REMOTE1_HIGH 0x50
#define LM83_REG_R_REMOTE2_TEMP 0x01
#define LM83_REG_R_REMOTE2_HIGH 0x07
#define LM83_REG_W_REMOTE2_HIGH 0x0D
#define LM83_REG_R_REMOTE3_TEMP 0x31
#define LM83_REG_R_REMOTE3_HIGH 0x3A
#define LM83_REG_W_REMOTE3_HIGH 0x52
#define LM83_REG_R_TCRIT 0x42
#define LM83_REG_W_TCRIT 0x5A
static const u8 LM83_REG_TEMP[] = {
LM83_REG_R_LOCAL_TEMP,
LM83_REG_R_REMOTE1_TEMP,
LM83_REG_R_REMOTE2_TEMP,
LM83_REG_R_REMOTE3_TEMP,
};
static const u8 LM83_REG_MAX[] = {
LM83_REG_R_LOCAL_HIGH,
LM83_REG_R_REMOTE1_HIGH,
LM83_REG_R_REMOTE2_HIGH,
LM83_REG_R_REMOTE3_HIGH,
};
/* alarm and fault registers and bits, indexed by channel */
static const u8 LM83_ALARM_REG[] = {
LM83_REG_R_STATUS1, LM83_REG_R_STATUS2, LM83_REG_R_STATUS1, LM83_REG_R_STATUS2
};
static const u8 LM83_MAX_ALARM_BIT[] = {
BIT(6), BIT(7), BIT(4), BIT(4)
};
static const u8 LM83_CRIT_ALARM_BIT[] = {
BIT(0), BIT(0), BIT(1), BIT(1)
};
static const u8 LM83_FAULT_BIT[] = {
0, BIT(5), BIT(2), BIT(2)
};
/*
* Client data (each client gets its own)
*/
struct lm83_data {
struct regmap *regmap;
enum chips type;
};
/* regmap code */
static int lm83_regmap_reg_read(void *context, unsigned int reg, unsigned int *val)
{
struct i2c_client *client = context;
int ret;
ret = i2c_smbus_read_byte_data(client, reg);
if (ret < 0)
return ret;
*val = ret;
return 0;
}
/*
* The regmap write function maps read register addresses to write register
* addresses. This is necessary for regmap register caching to work.
* An alternative would be to clear the regmap cache whenever a register is
* written, but that would be much more expensive.
*/
static int lm83_regmap_reg_write(void *context, unsigned int reg, unsigned int val)
{
struct i2c_client *client = context;
switch (reg) {
case LM83_REG_R_CONFIG:
case LM83_REG_R_LOCAL_HIGH:
case LM83_REG_R_REMOTE2_HIGH:
reg += 0x06;
break;
case LM83_REG_R_REMOTE1_HIGH:
case LM83_REG_R_REMOTE3_HIGH:
case LM83_REG_R_TCRIT:
reg += 0x18;
break;
default:
break;
}
return i2c_smbus_write_byte_data(client, reg, val);
}
static bool lm83_regmap_is_volatile(struct device *dev, unsigned int reg)
{
switch (reg) {
case LM83_REG_R_LOCAL_TEMP:
case LM83_REG_R_REMOTE1_TEMP:
case LM83_REG_R_REMOTE2_TEMP:
case LM83_REG_R_REMOTE3_TEMP:
case LM83_REG_R_STATUS1:
case LM83_REG_R_STATUS2:
return true;
default:
return false;
}
}
static const struct regmap_config lm83_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.cache_type = REGCACHE_RBTREE,
.volatile_reg = lm83_regmap_is_volatile,
.reg_read = lm83_regmap_reg_read,
.reg_write = lm83_regmap_reg_write,
};
/* hwmon API */
static int lm83_temp_read(struct device *dev, u32 attr, int channel, long *val)
{
struct lm83_data *data = dev_get_drvdata(dev);
unsigned int regval;
int err;
switch (attr) {
case hwmon_temp_input:
err = regmap_read(data->regmap, LM83_REG_TEMP[channel], &regval);
if (err < 0)
return err;
*val = (s8)regval * 1000;
break;
case hwmon_temp_max:
err = regmap_read(data->regmap, LM83_REG_MAX[channel], &regval);
if (err < 0)
return err;
*val = (s8)regval * 1000;
break;
case hwmon_temp_crit:
err = regmap_read(data->regmap, LM83_REG_R_TCRIT, &regval);
if (err < 0)
return err;
*val = (s8)regval * 1000;
break;
case hwmon_temp_max_alarm:
err = regmap_read(data->regmap, LM83_ALARM_REG[channel], &regval);
if (err < 0)
return err;
*val = !!(regval & LM83_MAX_ALARM_BIT[channel]);
break;
case hwmon_temp_crit_alarm:
err = regmap_read(data->regmap, LM83_ALARM_REG[channel], &regval);
if (err < 0)
return err;
*val = !!(regval & LM83_CRIT_ALARM_BIT[channel]);
break;
case hwmon_temp_fault:
err = regmap_read(data->regmap, LM83_ALARM_REG[channel], &regval);
if (err < 0)
return err;
*val = !!(regval & LM83_FAULT_BIT[channel]);
break;
default:
return -EOPNOTSUPP;
}
return 0;
}
static int lm83_temp_write(struct device *dev, u32 attr, int channel, long val)
{
struct lm83_data *data = dev_get_drvdata(dev);
unsigned int regval;
int err;
regval = DIV_ROUND_CLOSEST(clamp_val(val, -128000, 127000), 1000);
switch (attr) {
case hwmon_temp_max:
err = regmap_write(data->regmap, LM83_REG_MAX[channel], regval);
if (err < 0)
return err;
break;
case hwmon_temp_crit:
err = regmap_write(data->regmap, LM83_REG_R_TCRIT, regval);
if (err < 0)
return err;
break;
default:
return -EOPNOTSUPP;
}
return 0;
}
static int lm83_chip_read(struct device *dev, u32 attr, int channel, long *val)
{
struct lm83_data *data = dev_get_drvdata(dev);
unsigned int regval;
int err;
switch (attr) {
case hwmon_chip_alarms:
err = regmap_read(data->regmap, LM83_REG_R_STATUS1, &regval);
if (err < 0)
return err;
*val = regval;
err = regmap_read(data->regmap, LM83_REG_R_STATUS2, &regval);
if (err < 0)
return err;
*val |= regval << 8;
return 0;
default:
return -EOPNOTSUPP;
}
return 0;
}
static int lm83_read(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long *val)
{
switch (type) {
case hwmon_chip:
return lm83_chip_read(dev, attr, channel, val);
case hwmon_temp:
return lm83_temp_read(dev, attr, channel, val);
default:
return -EOPNOTSUPP;
}
}
static int lm83_write(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long val)
{
switch (type) {
case hwmon_temp:
return lm83_temp_write(dev, attr, channel, val);
default:
return -EOPNOTSUPP;
}
}
static umode_t lm83_is_visible(const void *_data, enum hwmon_sensor_types type,
u32 attr, int channel)
{
const struct lm83_data *data = _data;
/*
* LM82 only supports a single external channel, modeled as channel 2.
*/
if (data->type == lm82 && (channel == 1 || channel == 3))
return 0;
switch (type) {
case hwmon_chip:
if (attr == hwmon_chip_alarms)
return 0444;
break;
case hwmon_temp:
switch (attr) {
case hwmon_temp_input:
case hwmon_temp_max_alarm:
case hwmon_temp_crit_alarm:
return 0444;
case hwmon_temp_fault:
if (channel)
return 0444;
break;
case hwmon_temp_max:
return 0644;
case hwmon_temp_crit:
if (channel == 2)
return 0644;
return 0444;
default:
break;
}
break;
default:
break;
}
return 0;
}
static const struct hwmon_channel_info * const lm83_info[] = {
HWMON_CHANNEL_INFO(chip, HWMON_C_ALARMS),
HWMON_CHANNEL_INFO(temp,
HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM,
HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT,
HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT,
HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT
),
NULL
};
static const struct hwmon_ops lm83_hwmon_ops = {
.is_visible = lm83_is_visible,
.read = lm83_read,
.write = lm83_write,
};
static const struct hwmon_chip_info lm83_chip_info = {
.ops = &lm83_hwmon_ops,
.info = lm83_info,
};
/* Return 0 if detection is successful, -ENODEV otherwise */
static int lm83_detect(struct i2c_client *client,
struct i2c_board_info *info)
{
struct i2c_adapter *adapter = client->adapter;
const char *name;
u8 man_id, chip_id;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
return -ENODEV;
/* Detection */
if ((i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1) & 0xA8) ||
(i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2) & 0x48) ||
(i2c_smbus_read_byte_data(client, LM83_REG_R_CONFIG) & 0x41)) {
dev_dbg(&adapter->dev, "LM83 detection failed at 0x%02x\n",
client->addr);
return -ENODEV;
}
/* Identification */
man_id = i2c_smbus_read_byte_data(client, LM83_REG_R_MAN_ID);
if (man_id != 0x01) /* National Semiconductor */
return -ENODEV;
chip_id = i2c_smbus_read_byte_data(client, LM83_REG_R_CHIP_ID);
switch (chip_id) {
case 0x03:
/*
* According to the LM82 datasheet dated March 2013, recent
* revisions of LM82 have a die revision of 0x03. This was
* confirmed with a real chip. Further details in this revision
* of the LM82 datasheet strongly suggest that LM82 is just a
* repackaged LM83. It is therefore impossible to distinguish
* those chips from LM83, and they will be misdetected as LM83.
*/
name = "lm83";
break;
case 0x01:
name = "lm82";
break;
default:
/* identification failed */
dev_dbg(&adapter->dev,
"Unsupported chip (man_id=0x%02X, chip_id=0x%02X)\n",
man_id, chip_id);
return -ENODEV;
}
strscpy(info->type, name, I2C_NAME_SIZE);
return 0;
}
static const struct i2c_device_id lm83_id[] = {
{ "lm83", lm83 },
{ "lm82", lm82 },
{ }
};
MODULE_DEVICE_TABLE(i2c, lm83_id);
static int lm83_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
struct device *hwmon_dev;
struct lm83_data *data;
data = devm_kzalloc(dev, sizeof(struct lm83_data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->regmap = devm_regmap_init(dev, NULL, client, &lm83_regmap_config);
if (IS_ERR(data->regmap))
return PTR_ERR(data->regmap);
data->type = i2c_match_id(lm83_id, client)->driver_data;
hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
data, &lm83_chip_info, NULL);
return PTR_ERR_OR_ZERO(hwmon_dev);
}
/*
* Driver data (common to all clients)
*/
static struct i2c_driver lm83_driver = {
.class = I2C_CLASS_HWMON,
.driver = {
.name = "lm83",
},
.probe_new = lm83_probe,
.id_table = lm83_id,
.detect = lm83_detect,
.address_list = normal_i2c,
};
module_i2c_driver(lm83_driver);
MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
MODULE_DESCRIPTION("LM83 driver");
MODULE_LICENSE("GPL");
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