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linux/drivers/hwmon/ds1621.c
Andrew Davis 698d692cd8 hwmon: (ds1621) Remove use of i2c_match_id() 
The function i2c_match_id() is used to fetch the matching ID from
the i2c_device_id table. This is often used to then retrieve the
matching driver_data. This can be done in one step with the helper
i2c_get_match_data().

This helper has a couple other benefits:
 * It doesn't need the i2c_device_id passed in so we do not need
   to have that forward declared, allowing us to remove those or
   move the i2c_device_id table down to its more natural spot
   with the other module info.
 * It also checks for device match data, which allows for OF and
   ACPI based probing. That means we do not have to manually check
   those first and can remove those checks.

Signed-off-by: Andrew Davis <afd@ti.com>
Link: https://lore.kernel.org/r/20240403203633.914389-9-afd@ti.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2024-06-08 16:07:32 -07:00

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* ds1621.c - Part of lm_sensors, Linux kernel modules for hardware
* monitoring
* Christian W. Zuckschwerdt <zany@triq.net> 2000-11-23
* based on lm75.c by Frodo Looijaard <frodol@dds.nl>
* Ported to Linux 2.6 by Aurelien Jarno <aurelien@aurel32.net> with
* the help of Jean Delvare <jdelvare@suse.de>
*
* The DS1621 device is a digital temperature/thermometer with 9-bit
* resolution, a thermal alarm output (Tout), and user-defined minimum
* and maximum temperature thresholds (TH and TL).
*
* The DS1625, DS1631, DS1721, and DS1731 are pin compatible with the DS1621
* and similar in operation, with slight variations as noted in the device
* datasheets (please refer to www.maximintegrated.com for specific
* device information).
*
* Since the DS1621 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.
*/
#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>
#include <linux/sysfs.h>
#include <linux/kernel.h>
/* Supported devices */
enum chips { ds1621, ds1625, ds1631, ds1721, ds1731 };
/* Insmod parameters */
static int polarity = -1;
module_param(polarity, int, 0);
MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low");
/*
* The Configuration/Status register
*
* - DS1621:
* 7 6 5 4 3 2 1 0
* |Done|THF |TLF |NVB | X | X |POL |1SHOT|
*
* - DS1625:
* 7 6 5 4 3 2 1 0
* |Done|THF |TLF |NVB | 1 | 0 |POL |1SHOT|
*
* - DS1631, DS1731:
* 7 6 5 4 3 2 1 0
* |Done|THF |TLF |NVB | R1 | R0 |POL |1SHOT|
*
* - DS1721:
* 7 6 5 4 3 2 1 0
* |Done| X | X | U | R1 | R0 |POL |1SHOT|
*
* Where:
* - 'X' is Reserved
* - 'U' is Undefined
*/
#define DS1621_REG_CONFIG_NVB 0x10
#define DS1621_REG_CONFIG_RESOL 0x0C
#define DS1621_REG_CONFIG_POLARITY 0x02
#define DS1621_REG_CONFIG_1SHOT 0x01
#define DS1621_REG_CONFIG_DONE 0x80
#define DS1621_REG_CONFIG_RESOL_SHIFT 2
/* ds1721 conversion rates: {C/LSB, time(ms), resolution bit setting} */
static const unsigned short ds1721_convrates[] = {
94, /* 9-bits (0.5, 93.75, RES[0..1] = 0 */
188, /* 10-bits (0.25, 187.5, RES[0..1] = 1 */
375, /* 11-bits (0.125, 375, RES[0..1] = 2 */
750, /* 12-bits (0.0625, 750, RES[0..1] = 3 */
};
#define DS1621_CONVERSION_MAX 750
#define DS1625_CONVERSION_MAX 500
#define DS1621_TEMP_MAX 125000
#define DS1621_TEMP_MIN (-55000)
/* The DS1621 temperature registers */
static const u8 DS1621_REG_TEMP[3] = {
0xAA, /* input, word, RO */
0xA2, /* min, word, RW */
0xA1, /* max, word, RW */
};
#define DS1621_REG_CONF 0xAC /* byte, RW */
#define DS1621_COM_START 0xEE /* no data */
#define DS1721_COM_START 0x51 /* no data */
#define DS1621_COM_STOP 0x22 /* no data */
/* The DS1621 configuration register */
#define DS1621_ALARM_TEMP_HIGH 0x40
#define DS1621_ALARM_TEMP_LOW 0x20
/* Conversions */
#define ALARMS_FROM_REG(val) ((val) & \
(DS1621_ALARM_TEMP_HIGH | DS1621_ALARM_TEMP_LOW))
/* Each client has this additional data */
struct ds1621_data {
struct i2c_client *client;
struct mutex update_lock;
bool valid; /* true if following fields are valid */
unsigned long last_updated; /* In jiffies */
enum chips kind; /* device type */
u16 temp[3]; /* Register values, word */
u8 conf; /* Register encoding, combined */
u8 zbits; /* Resolution encoded as number of
* zero bits */
u16 update_interval; /* Conversion rate in milliseconds */
};
static inline int DS1621_TEMP_FROM_REG(u16 reg)
{
return DIV_ROUND_CLOSEST(((s16)reg / 16) * 625, 10);
}
/*
* TEMP: 0.001C/bit (-55C to +125C)
* REG:
* - 1621, 1625: 0.5C/bit, 7 zero-bits
* - 1631, 1721, 1731: 0.0625C/bit, 4 zero-bits
*/
static inline u16 DS1621_TEMP_TO_REG(long temp, u8 zbits)
{
temp = clamp_val(temp, DS1621_TEMP_MIN, DS1621_TEMP_MAX);
temp = DIV_ROUND_CLOSEST(temp * (1 << (8 - zbits)), 1000) << zbits;
return temp;
}
static void ds1621_init_client(struct ds1621_data *data,
struct i2c_client *client)
{
u8 conf, new_conf, sreg, resol;
new_conf = conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);
/* switch to continuous conversion mode */
new_conf &= ~DS1621_REG_CONFIG_1SHOT;
/* setup output polarity */
if (polarity == 0)
new_conf &= ~DS1621_REG_CONFIG_POLARITY;
else if (polarity == 1)
new_conf |= DS1621_REG_CONFIG_POLARITY;
if (conf != new_conf)
i2c_smbus_write_byte_data(client, DS1621_REG_CONF, new_conf);
switch (data->kind) {
case ds1625:
data->update_interval = DS1625_CONVERSION_MAX;
data->zbits = 7;
sreg = DS1621_COM_START;
break;
case ds1631:
case ds1721:
case ds1731:
resol = (new_conf & DS1621_REG_CONFIG_RESOL) >>
DS1621_REG_CONFIG_RESOL_SHIFT;
data->update_interval = ds1721_convrates[resol];
data->zbits = 7 - resol;
sreg = DS1721_COM_START;
break;
default:
data->update_interval = DS1621_CONVERSION_MAX;
data->zbits = 7;
sreg = DS1621_COM_START;
break;
}
/* start conversion */
i2c_smbus_write_byte(client, sreg);
}
static struct ds1621_data *ds1621_update_client(struct device *dev)
{
struct ds1621_data *data = dev_get_drvdata(dev);
struct i2c_client *client = data->client;
u8 new_conf;
mutex_lock(&data->update_lock);
if (time_after(jiffies, data->last_updated + data->update_interval) ||
!data->valid) {
int i;
dev_dbg(&client->dev, "Starting ds1621 update\n");
data->conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);
for (i = 0; i < ARRAY_SIZE(data->temp); i++)
data->temp[i] = i2c_smbus_read_word_swapped(client,
DS1621_REG_TEMP[i]);
/* reset alarms if necessary */
new_conf = data->conf;
if (data->temp[0] > data->temp[1]) /* input > min */
new_conf &= ~DS1621_ALARM_TEMP_LOW;
if (data->temp[0] < data->temp[2]) /* input < max */
new_conf &= ~DS1621_ALARM_TEMP_HIGH;
if (data->conf != new_conf)
i2c_smbus_write_byte_data(client, DS1621_REG_CONF,
new_conf);
data->last_updated = jiffies;
data->valid = true;
}
mutex_unlock(&data->update_lock);
return data;
}
static ssize_t temp_show(struct device *dev, struct device_attribute *da,
char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
struct ds1621_data *data = ds1621_update_client(dev);
return sprintf(buf, "%d\n",
DS1621_TEMP_FROM_REG(data->temp[attr->index]));
}
static ssize_t temp_store(struct device *dev, struct device_attribute *da,
const char *buf, size_t count)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
struct ds1621_data *data = dev_get_drvdata(dev);
long val;
int err;
err = kstrtol(buf, 10, &val);
if (err)
return err;
mutex_lock(&data->update_lock);
data->temp[attr->index] = DS1621_TEMP_TO_REG(val, data->zbits);
i2c_smbus_write_word_swapped(data->client, DS1621_REG_TEMP[attr->index],
data->temp[attr->index]);
mutex_unlock(&data->update_lock);
return count;
}
static ssize_t alarms_show(struct device *dev, struct device_attribute *da,
char *buf)
{
struct ds1621_data *data = ds1621_update_client(dev);
return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf));
}
static ssize_t alarm_show(struct device *dev, struct device_attribute *da,
char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
struct ds1621_data *data = ds1621_update_client(dev);
return sprintf(buf, "%d\n", !!(data->conf & attr->index));
}
static ssize_t update_interval_show(struct device *dev,
struct device_attribute *da, char *buf)
{
struct ds1621_data *data = dev_get_drvdata(dev);
return sysfs_emit(buf, "%hu\n", data->update_interval);
}
static ssize_t update_interval_store(struct device *dev,
struct device_attribute *da,
const char *buf, size_t count)
{
struct ds1621_data *data = dev_get_drvdata(dev);
struct i2c_client *client = data->client;
unsigned long convrate;
s32 err;
int resol = 0;
err = kstrtoul(buf, 10, &convrate);
if (err)
return err;
/* Convert rate into resolution bits */
while (resol < (ARRAY_SIZE(ds1721_convrates) - 1) &&
convrate > ds1721_convrates[resol])
resol++;
mutex_lock(&data->update_lock);
data->conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);
data->conf &= ~DS1621_REG_CONFIG_RESOL;
data->conf |= (resol << DS1621_REG_CONFIG_RESOL_SHIFT);
i2c_smbus_write_byte_data(client, DS1621_REG_CONF, data->conf);
data->update_interval = ds1721_convrates[resol];
data->zbits = 7 - resol;
mutex_unlock(&data->update_lock);
return count;
}
static DEVICE_ATTR_RO(alarms);
static DEVICE_ATTR_RW(update_interval);
static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0);
static SENSOR_DEVICE_ATTR_RW(temp1_min, temp, 1);
static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, 2);
static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, alarm, DS1621_ALARM_TEMP_LOW);
static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, DS1621_ALARM_TEMP_HIGH);
static struct attribute *ds1621_attributes[] = {
&sensor_dev_attr_temp1_input.dev_attr.attr,
&sensor_dev_attr_temp1_min.dev_attr.attr,
&sensor_dev_attr_temp1_max.dev_attr.attr,
&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
&dev_attr_alarms.attr,
&dev_attr_update_interval.attr,
NULL
};
static umode_t ds1621_attribute_visible(struct kobject *kobj,
struct attribute *attr, int index)
{
struct device *dev = kobj_to_dev(kobj);
struct ds1621_data *data = dev_get_drvdata(dev);
if (attr == &dev_attr_update_interval.attr)
if (data->kind == ds1621 || data->kind == ds1625)
/* shhh, we're hiding update_interval */
return 0;
return attr->mode;
}
static const struct attribute_group ds1621_group = {
.attrs = ds1621_attributes,
.is_visible = ds1621_attribute_visible
};
__ATTRIBUTE_GROUPS(ds1621);
static int ds1621_probe(struct i2c_client *client)
{
struct ds1621_data *data;
struct device *hwmon_dev;
data = devm_kzalloc(&client->dev, sizeof(struct ds1621_data),
GFP_KERNEL);
if (!data)
return -ENOMEM;
mutex_init(&data->update_lock);
data->kind = (uintptr_t)i2c_get_match_data(client);
data->client = client;
/* Initialize the DS1621 chip */
ds1621_init_client(data, client);
hwmon_dev = devm_hwmon_device_register_with_groups(&client->dev,
client->name, data,
ds1621_groups);
return PTR_ERR_OR_ZERO(hwmon_dev);
}
static const struct i2c_device_id ds1621_id[] = {
{ "ds1621", ds1621 },
{ "ds1625", ds1625 },
{ "ds1631", ds1631 },
{ "ds1721", ds1721 },
{ "ds1731", ds1731 },
{ }
};
MODULE_DEVICE_TABLE(i2c, ds1621_id);
/* This is the driver that will be inserted */
static struct i2c_driver ds1621_driver = {
.driver = {
.name = "ds1621",
},
.probe = ds1621_probe,
.id_table = ds1621_id,
};
module_i2c_driver(ds1621_driver);
MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>");
MODULE_DESCRIPTION("DS1621 driver");
MODULE_LICENSE("GPL");
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