1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * ds1621.c - Part of lm_sensors, Linux kernel modules for hardware
5 * Christian W. Zuckschwerdt <zany@triq.net> 2000-11-23
6 * based on lm75.c by Frodo Looijaard <frodol@dds.nl>
7 * Ported to Linux 2.6 by Aurelien Jarno <aurelien@aurel32.net> with
8 * the help of Jean Delvare <jdelvare@suse.de>
10 * The DS1621 device is a digital temperature/thermometer with 9-bit
11 * resolution, a thermal alarm output (Tout), and user-defined minimum
12 * and maximum temperature thresholds (TH and TL).
14 * The DS1625, DS1631, DS1721, and DS1731 are pin compatible with the DS1621
15 * and similar in operation, with slight variations as noted in the device
16 * datasheets (please refer to www.maximintegrated.com for specific
17 * device information).
19 * Since the DS1621 was the first chipset supported by this driver,
20 * most comments will refer to this chipset, but are actually general
21 * and concern all supported chipsets, unless mentioned otherwise.
24 #include <linux/module.h>
25 #include <linux/init.h>
26 #include <linux/slab.h>
27 #include <linux/jiffies.h>
28 #include <linux/i2c.h>
29 #include <linux/hwmon.h>
30 #include <linux/hwmon-sysfs.h>
31 #include <linux/err.h>
32 #include <linux/mutex.h>
33 #include <linux/sysfs.h>
34 #include <linux/kernel.h>
36 /* Supported devices */
37 enum chips
{ ds1621
, ds1625
, ds1631
, ds1721
, ds1731
};
39 /* Insmod parameters */
40 static int polarity
= -1;
41 module_param(polarity
, int, 0);
42 MODULE_PARM_DESC(polarity
, "Output's polarity: 0 = active high, 1 = active low");
45 * The Configuration/Status register
49 * |Done|THF |TLF |NVB | X | X |POL |1SHOT|
53 * |Done|THF |TLF |NVB | 1 | 0 |POL |1SHOT|
57 * |Done|THF |TLF |NVB | R1 | R0 |POL |1SHOT|
61 * |Done| X | X | U | R1 | R0 |POL |1SHOT|
67 #define DS1621_REG_CONFIG_NVB 0x10
68 #define DS1621_REG_CONFIG_RESOL 0x0C
69 #define DS1621_REG_CONFIG_POLARITY 0x02
70 #define DS1621_REG_CONFIG_1SHOT 0x01
71 #define DS1621_REG_CONFIG_DONE 0x80
73 #define DS1621_REG_CONFIG_RESOL_SHIFT 2
75 /* ds1721 conversion rates: {C/LSB, time(ms), resolution bit setting} */
76 static const unsigned short ds1721_convrates
[] = {
77 94, /* 9-bits (0.5, 93.75, RES[0..1] = 0 */
78 188, /* 10-bits (0.25, 187.5, RES[0..1] = 1 */
79 375, /* 11-bits (0.125, 375, RES[0..1] = 2 */
80 750, /* 12-bits (0.0625, 750, RES[0..1] = 3 */
83 #define DS1621_CONVERSION_MAX 750
84 #define DS1625_CONVERSION_MAX 500
86 #define DS1621_TEMP_MAX 125000
87 #define DS1621_TEMP_MIN (-55000)
89 /* The DS1621 temperature registers */
90 static const u8 DS1621_REG_TEMP
[3] = {
91 0xAA, /* input, word, RO */
92 0xA2, /* min, word, RW */
93 0xA1, /* max, word, RW */
95 #define DS1621_REG_CONF 0xAC /* byte, RW */
96 #define DS1621_COM_START 0xEE /* no data */
97 #define DS1721_COM_START 0x51 /* no data */
98 #define DS1621_COM_STOP 0x22 /* no data */
100 /* The DS1621 configuration register */
101 #define DS1621_ALARM_TEMP_HIGH 0x40
102 #define DS1621_ALARM_TEMP_LOW 0x20
105 #define ALARMS_FROM_REG(val) ((val) & \
106 (DS1621_ALARM_TEMP_HIGH | DS1621_ALARM_TEMP_LOW))
108 /* Each client has this additional data */
110 struct i2c_client
*client
;
111 struct mutex update_lock
;
112 char valid
; /* !=0 if following fields are valid */
113 unsigned long last_updated
; /* In jiffies */
114 enum chips kind
; /* device type */
116 u16 temp
[3]; /* Register values, word */
117 u8 conf
; /* Register encoding, combined */
118 u8 zbits
; /* Resolution encoded as number of
120 u16 update_interval
; /* Conversion rate in milliseconds */
123 static inline int DS1621_TEMP_FROM_REG(u16 reg
)
125 return DIV_ROUND_CLOSEST(((s16
)reg
/ 16) * 625, 10);
129 * TEMP: 0.001C/bit (-55C to +125C)
131 * - 1621, 1625: 0.5C/bit, 7 zero-bits
132 * - 1631, 1721, 1731: 0.0625C/bit, 4 zero-bits
134 static inline u16
DS1621_TEMP_TO_REG(long temp
, u8 zbits
)
136 temp
= clamp_val(temp
, DS1621_TEMP_MIN
, DS1621_TEMP_MAX
);
137 temp
= DIV_ROUND_CLOSEST(temp
* (1 << (8 - zbits
)), 1000) << zbits
;
141 static void ds1621_init_client(struct ds1621_data
*data
,
142 struct i2c_client
*client
)
144 u8 conf
, new_conf
, sreg
, resol
;
146 new_conf
= conf
= i2c_smbus_read_byte_data(client
, DS1621_REG_CONF
);
147 /* switch to continuous conversion mode */
148 new_conf
&= ~DS1621_REG_CONFIG_1SHOT
;
150 /* setup output polarity */
152 new_conf
&= ~DS1621_REG_CONFIG_POLARITY
;
153 else if (polarity
== 1)
154 new_conf
|= DS1621_REG_CONFIG_POLARITY
;
156 if (conf
!= new_conf
)
157 i2c_smbus_write_byte_data(client
, DS1621_REG_CONF
, new_conf
);
159 switch (data
->kind
) {
161 data
->update_interval
= DS1625_CONVERSION_MAX
;
163 sreg
= DS1621_COM_START
;
168 resol
= (new_conf
& DS1621_REG_CONFIG_RESOL
) >>
169 DS1621_REG_CONFIG_RESOL_SHIFT
;
170 data
->update_interval
= ds1721_convrates
[resol
];
171 data
->zbits
= 7 - resol
;
172 sreg
= DS1721_COM_START
;
175 data
->update_interval
= DS1621_CONVERSION_MAX
;
177 sreg
= DS1621_COM_START
;
181 /* start conversion */
182 i2c_smbus_write_byte(client
, sreg
);
185 static struct ds1621_data
*ds1621_update_client(struct device
*dev
)
187 struct ds1621_data
*data
= dev_get_drvdata(dev
);
188 struct i2c_client
*client
= data
->client
;
191 mutex_lock(&data
->update_lock
);
193 if (time_after(jiffies
, data
->last_updated
+ data
->update_interval
) ||
197 dev_dbg(&client
->dev
, "Starting ds1621 update\n");
199 data
->conf
= i2c_smbus_read_byte_data(client
, DS1621_REG_CONF
);
201 for (i
= 0; i
< ARRAY_SIZE(data
->temp
); i
++)
202 data
->temp
[i
] = i2c_smbus_read_word_swapped(client
,
205 /* reset alarms if necessary */
206 new_conf
= data
->conf
;
207 if (data
->temp
[0] > data
->temp
[1]) /* input > min */
208 new_conf
&= ~DS1621_ALARM_TEMP_LOW
;
209 if (data
->temp
[0] < data
->temp
[2]) /* input < max */
210 new_conf
&= ~DS1621_ALARM_TEMP_HIGH
;
211 if (data
->conf
!= new_conf
)
212 i2c_smbus_write_byte_data(client
, DS1621_REG_CONF
,
215 data
->last_updated
= jiffies
;
219 mutex_unlock(&data
->update_lock
);
224 static ssize_t
temp_show(struct device
*dev
, struct device_attribute
*da
,
227 struct sensor_device_attribute
*attr
= to_sensor_dev_attr(da
);
228 struct ds1621_data
*data
= ds1621_update_client(dev
);
229 return sprintf(buf
, "%d\n",
230 DS1621_TEMP_FROM_REG(data
->temp
[attr
->index
]));
233 static ssize_t
temp_store(struct device
*dev
, struct device_attribute
*da
,
234 const char *buf
, size_t count
)
236 struct sensor_device_attribute
*attr
= to_sensor_dev_attr(da
);
237 struct ds1621_data
*data
= dev_get_drvdata(dev
);
241 err
= kstrtol(buf
, 10, &val
);
245 mutex_lock(&data
->update_lock
);
246 data
->temp
[attr
->index
] = DS1621_TEMP_TO_REG(val
, data
->zbits
);
247 i2c_smbus_write_word_swapped(data
->client
, DS1621_REG_TEMP
[attr
->index
],
248 data
->temp
[attr
->index
]);
249 mutex_unlock(&data
->update_lock
);
253 static ssize_t
alarms_show(struct device
*dev
, struct device_attribute
*da
,
256 struct ds1621_data
*data
= ds1621_update_client(dev
);
257 return sprintf(buf
, "%d\n", ALARMS_FROM_REG(data
->conf
));
260 static ssize_t
alarm_show(struct device
*dev
, struct device_attribute
*da
,
263 struct sensor_device_attribute
*attr
= to_sensor_dev_attr(da
);
264 struct ds1621_data
*data
= ds1621_update_client(dev
);
265 return sprintf(buf
, "%d\n", !!(data
->conf
& attr
->index
));
268 static ssize_t
update_interval_show(struct device
*dev
,
269 struct device_attribute
*da
, char *buf
)
271 struct ds1621_data
*data
= dev_get_drvdata(dev
);
272 return scnprintf(buf
, PAGE_SIZE
, "%hu\n", data
->update_interval
);
275 static ssize_t
update_interval_store(struct device
*dev
,
276 struct device_attribute
*da
,
277 const char *buf
, size_t count
)
279 struct ds1621_data
*data
= dev_get_drvdata(dev
);
280 struct i2c_client
*client
= data
->client
;
281 unsigned long convrate
;
285 err
= kstrtoul(buf
, 10, &convrate
);
289 /* Convert rate into resolution bits */
290 while (resol
< (ARRAY_SIZE(ds1721_convrates
) - 1) &&
291 convrate
> ds1721_convrates
[resol
])
294 mutex_lock(&data
->update_lock
);
295 data
->conf
= i2c_smbus_read_byte_data(client
, DS1621_REG_CONF
);
296 data
->conf
&= ~DS1621_REG_CONFIG_RESOL
;
297 data
->conf
|= (resol
<< DS1621_REG_CONFIG_RESOL_SHIFT
);
298 i2c_smbus_write_byte_data(client
, DS1621_REG_CONF
, data
->conf
);
299 data
->update_interval
= ds1721_convrates
[resol
];
300 data
->zbits
= 7 - resol
;
301 mutex_unlock(&data
->update_lock
);
306 static DEVICE_ATTR_RO(alarms
);
307 static DEVICE_ATTR_RW(update_interval
);
309 static SENSOR_DEVICE_ATTR_RO(temp1_input
, temp
, 0);
310 static SENSOR_DEVICE_ATTR_RW(temp1_min
, temp
, 1);
311 static SENSOR_DEVICE_ATTR_RW(temp1_max
, temp
, 2);
312 static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm
, alarm
, DS1621_ALARM_TEMP_LOW
);
313 static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm
, alarm
, DS1621_ALARM_TEMP_HIGH
);
315 static struct attribute
*ds1621_attributes
[] = {
316 &sensor_dev_attr_temp1_input
.dev_attr
.attr
,
317 &sensor_dev_attr_temp1_min
.dev_attr
.attr
,
318 &sensor_dev_attr_temp1_max
.dev_attr
.attr
,
319 &sensor_dev_attr_temp1_min_alarm
.dev_attr
.attr
,
320 &sensor_dev_attr_temp1_max_alarm
.dev_attr
.attr
,
321 &dev_attr_alarms
.attr
,
322 &dev_attr_update_interval
.attr
,
326 static umode_t
ds1621_attribute_visible(struct kobject
*kobj
,
327 struct attribute
*attr
, int index
)
329 struct device
*dev
= kobj_to_dev(kobj
);
330 struct ds1621_data
*data
= dev_get_drvdata(dev
);
332 if (attr
== &dev_attr_update_interval
.attr
)
333 if (data
->kind
== ds1621
|| data
->kind
== ds1625
)
334 /* shhh, we're hiding update_interval */
339 static const struct attribute_group ds1621_group
= {
340 .attrs
= ds1621_attributes
,
341 .is_visible
= ds1621_attribute_visible
343 __ATTRIBUTE_GROUPS(ds1621
);
345 static const struct i2c_device_id ds1621_id
[];
347 static int ds1621_probe(struct i2c_client
*client
)
349 struct ds1621_data
*data
;
350 struct device
*hwmon_dev
;
352 data
= devm_kzalloc(&client
->dev
, sizeof(struct ds1621_data
),
357 mutex_init(&data
->update_lock
);
359 data
->kind
= i2c_match_id(ds1621_id
, client
)->driver_data
;
360 data
->client
= client
;
362 /* Initialize the DS1621 chip */
363 ds1621_init_client(data
, client
);
365 hwmon_dev
= devm_hwmon_device_register_with_groups(&client
->dev
,
368 return PTR_ERR_OR_ZERO(hwmon_dev
);
371 static const struct i2c_device_id ds1621_id
[] = {
372 { "ds1621", ds1621
},
373 { "ds1625", ds1625
},
374 { "ds1631", ds1631
},
375 { "ds1721", ds1721
},
376 { "ds1731", ds1731
},
379 MODULE_DEVICE_TABLE(i2c
, ds1621_id
);
381 /* This is the driver that will be inserted */
382 static struct i2c_driver ds1621_driver
= {
383 .class = I2C_CLASS_HWMON
,
387 .probe_new
= ds1621_probe
,
388 .id_table
= ds1621_id
,
391 module_i2c_driver(ds1621_driver
);
393 MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>");
394 MODULE_DESCRIPTION("DS1621 driver");
395 MODULE_LICENSE("GPL");