2 * ds1621.c - Part of lm_sensors, Linux kernel modules for hardware
4 * Christian W. Zuckschwerdt <zany@triq.net> 2000-11-23
5 * based on lm75.c by Frodo Looijaard <frodol@dds.nl>
6 * Ported to Linux 2.6 by Aurelien Jarno <aurelien@aurel32.net> with
7 * the help of Jean Delvare <jdelvare@suse.de>
9 * The DS1621 device is a digital temperature/thermometer with 9-bit
10 * resolution, a thermal alarm output (Tout), and user-defined minimum
11 * and maximum temperature thresholds (TH and TL).
13 * The DS1625, DS1631, DS1721, and DS1731 are pin compatible with the DS1621
14 * and similar in operation, with slight variations as noted in the device
15 * datasheets (please refer to www.maximintegrated.com for specific
16 * device information).
18 * Since the DS1621 was the first chipset supported by this driver,
19 * most comments will refer to this chipset, but are actually general
20 * and concern all supported chipsets, unless mentioned otherwise.
22 * This program is free software; you can redistribute it and/or modify
23 * it under the terms of the GNU General Public License as published by
24 * the Free Software Foundation; either version 2 of the License, or
25 * (at your option) any later version.
27 * This program is distributed in the hope that it will be useful,
28 * but WITHOUT ANY WARRANTY; without even the implied warranty of
29 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
30 * GNU General Public License for more details.
32 * You should have received a copy of the GNU General Public License
33 * along with this program; if not, write to the Free Software
34 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
37 #include <linux/module.h>
38 #include <linux/init.h>
39 #include <linux/slab.h>
40 #include <linux/jiffies.h>
41 #include <linux/i2c.h>
42 #include <linux/hwmon.h>
43 #include <linux/hwmon-sysfs.h>
44 #include <linux/err.h>
45 #include <linux/mutex.h>
46 #include <linux/sysfs.h>
47 #include <linux/kernel.h>
49 /* Supported devices */
50 enum chips
{ ds1621
, ds1625
, ds1631
, ds1721
, ds1731
};
52 /* Insmod parameters */
53 static int polarity
= -1;
54 module_param(polarity
, int, 0);
55 MODULE_PARM_DESC(polarity
, "Output's polarity: 0 = active high, 1 = active low");
58 * The Configuration/Status register
62 * |Done|THF |TLF |NVB | X | X |POL |1SHOT|
66 * |Done|THF |TLF |NVB | 1 | 0 |POL |1SHOT|
70 * |Done|THF |TLF |NVB | R1 | R0 |POL |1SHOT|
74 * |Done| X | X | U | R1 | R0 |POL |1SHOT|
80 #define DS1621_REG_CONFIG_NVB 0x10
81 #define DS1621_REG_CONFIG_RESOL 0x0C
82 #define DS1621_REG_CONFIG_POLARITY 0x02
83 #define DS1621_REG_CONFIG_1SHOT 0x01
84 #define DS1621_REG_CONFIG_DONE 0x80
86 #define DS1621_REG_CONFIG_RESOL_SHIFT 2
88 /* ds1721 conversion rates: {C/LSB, time(ms), resolution bit setting} */
89 static const unsigned short ds1721_convrates
[] = {
90 94, /* 9-bits (0.5, 93.75, RES[0..1] = 0 */
91 188, /* 10-bits (0.25, 187.5, RES[0..1] = 1 */
92 375, /* 11-bits (0.125, 375, RES[0..1] = 2 */
93 750, /* 12-bits (0.0625, 750, RES[0..1] = 3 */
96 #define DS1621_CONVERSION_MAX 750
97 #define DS1625_CONVERSION_MAX 500
99 #define DS1621_TEMP_MAX 125000
100 #define DS1621_TEMP_MIN (-55000)
102 /* The DS1621 temperature registers */
103 static const u8 DS1621_REG_TEMP
[3] = {
104 0xAA, /* input, word, RO */
105 0xA2, /* min, word, RW */
106 0xA1, /* max, word, RW */
108 #define DS1621_REG_CONF 0xAC /* byte, RW */
109 #define DS1621_COM_START 0xEE /* no data */
110 #define DS1721_COM_START 0x51 /* no data */
111 #define DS1621_COM_STOP 0x22 /* no data */
113 /* The DS1621 configuration register */
114 #define DS1621_ALARM_TEMP_HIGH 0x40
115 #define DS1621_ALARM_TEMP_LOW 0x20
118 #define ALARMS_FROM_REG(val) ((val) & \
119 (DS1621_ALARM_TEMP_HIGH | DS1621_ALARM_TEMP_LOW))
121 /* Each client has this additional data */
123 struct i2c_client
*client
;
124 struct mutex update_lock
;
125 char valid
; /* !=0 if following fields are valid */
126 unsigned long last_updated
; /* In jiffies */
127 enum chips kind
; /* device type */
129 u16 temp
[3]; /* Register values, word */
130 u8 conf
; /* Register encoding, combined */
131 u8 zbits
; /* Resolution encoded as number of
133 u16 update_interval
; /* Conversion rate in milliseconds */
136 static inline int DS1621_TEMP_FROM_REG(u16 reg
)
138 return DIV_ROUND_CLOSEST(((s16
)reg
/ 16) * 625, 10);
142 * TEMP: 0.001C/bit (-55C to +125C)
144 * - 1621, 1625: 0.5C/bit, 7 zero-bits
145 * - 1631, 1721, 1731: 0.0625C/bit, 4 zero-bits
147 static inline u16
DS1621_TEMP_TO_REG(long temp
, u8 zbits
)
149 temp
= clamp_val(temp
, DS1621_TEMP_MIN
, DS1621_TEMP_MAX
);
150 temp
= DIV_ROUND_CLOSEST(temp
* (1 << (8 - zbits
)), 1000) << zbits
;
154 static void ds1621_init_client(struct ds1621_data
*data
,
155 struct i2c_client
*client
)
157 u8 conf
, new_conf
, sreg
, resol
;
159 new_conf
= conf
= i2c_smbus_read_byte_data(client
, DS1621_REG_CONF
);
160 /* switch to continuous conversion mode */
161 new_conf
&= ~DS1621_REG_CONFIG_1SHOT
;
163 /* setup output polarity */
165 new_conf
&= ~DS1621_REG_CONFIG_POLARITY
;
166 else if (polarity
== 1)
167 new_conf
|= DS1621_REG_CONFIG_POLARITY
;
169 if (conf
!= new_conf
)
170 i2c_smbus_write_byte_data(client
, DS1621_REG_CONF
, new_conf
);
172 switch (data
->kind
) {
174 data
->update_interval
= DS1625_CONVERSION_MAX
;
176 sreg
= DS1621_COM_START
;
181 resol
= (new_conf
& DS1621_REG_CONFIG_RESOL
) >>
182 DS1621_REG_CONFIG_RESOL_SHIFT
;
183 data
->update_interval
= ds1721_convrates
[resol
];
184 data
->zbits
= 7 - resol
;
185 sreg
= DS1721_COM_START
;
188 data
->update_interval
= DS1621_CONVERSION_MAX
;
190 sreg
= DS1621_COM_START
;
194 /* start conversion */
195 i2c_smbus_write_byte(client
, sreg
);
198 static struct ds1621_data
*ds1621_update_client(struct device
*dev
)
200 struct ds1621_data
*data
= dev_get_drvdata(dev
);
201 struct i2c_client
*client
= data
->client
;
204 mutex_lock(&data
->update_lock
);
206 if (time_after(jiffies
, data
->last_updated
+ data
->update_interval
) ||
210 dev_dbg(&client
->dev
, "Starting ds1621 update\n");
212 data
->conf
= i2c_smbus_read_byte_data(client
, DS1621_REG_CONF
);
214 for (i
= 0; i
< ARRAY_SIZE(data
->temp
); i
++)
215 data
->temp
[i
] = i2c_smbus_read_word_swapped(client
,
218 /* reset alarms if necessary */
219 new_conf
= data
->conf
;
220 if (data
->temp
[0] > data
->temp
[1]) /* input > min */
221 new_conf
&= ~DS1621_ALARM_TEMP_LOW
;
222 if (data
->temp
[0] < data
->temp
[2]) /* input < max */
223 new_conf
&= ~DS1621_ALARM_TEMP_HIGH
;
224 if (data
->conf
!= new_conf
)
225 i2c_smbus_write_byte_data(client
, DS1621_REG_CONF
,
228 data
->last_updated
= jiffies
;
232 mutex_unlock(&data
->update_lock
);
237 static ssize_t
show_temp(struct device
*dev
, struct device_attribute
*da
,
240 struct sensor_device_attribute
*attr
= to_sensor_dev_attr(da
);
241 struct ds1621_data
*data
= ds1621_update_client(dev
);
242 return sprintf(buf
, "%d\n",
243 DS1621_TEMP_FROM_REG(data
->temp
[attr
->index
]));
246 static ssize_t
set_temp(struct device
*dev
, struct device_attribute
*da
,
247 const char *buf
, size_t count
)
249 struct sensor_device_attribute
*attr
= to_sensor_dev_attr(da
);
250 struct ds1621_data
*data
= dev_get_drvdata(dev
);
254 err
= kstrtol(buf
, 10, &val
);
258 mutex_lock(&data
->update_lock
);
259 data
->temp
[attr
->index
] = DS1621_TEMP_TO_REG(val
, data
->zbits
);
260 i2c_smbus_write_word_swapped(data
->client
, DS1621_REG_TEMP
[attr
->index
],
261 data
->temp
[attr
->index
]);
262 mutex_unlock(&data
->update_lock
);
266 static ssize_t
alarms_show(struct device
*dev
, struct device_attribute
*da
,
269 struct ds1621_data
*data
= ds1621_update_client(dev
);
270 return sprintf(buf
, "%d\n", ALARMS_FROM_REG(data
->conf
));
273 static ssize_t
show_alarm(struct device
*dev
, struct device_attribute
*da
,
276 struct sensor_device_attribute
*attr
= to_sensor_dev_attr(da
);
277 struct ds1621_data
*data
= ds1621_update_client(dev
);
278 return sprintf(buf
, "%d\n", !!(data
->conf
& attr
->index
));
281 static ssize_t
update_interval_show(struct device
*dev
,
282 struct device_attribute
*da
, char *buf
)
284 struct ds1621_data
*data
= dev_get_drvdata(dev
);
285 return scnprintf(buf
, PAGE_SIZE
, "%hu\n", data
->update_interval
);
288 static ssize_t
update_interval_store(struct device
*dev
,
289 struct device_attribute
*da
,
290 const char *buf
, size_t count
)
292 struct ds1621_data
*data
= dev_get_drvdata(dev
);
293 struct i2c_client
*client
= data
->client
;
294 unsigned long convrate
;
298 err
= kstrtoul(buf
, 10, &convrate
);
302 /* Convert rate into resolution bits */
303 while (resol
< (ARRAY_SIZE(ds1721_convrates
) - 1) &&
304 convrate
> ds1721_convrates
[resol
])
307 mutex_lock(&data
->update_lock
);
308 data
->conf
= i2c_smbus_read_byte_data(client
, DS1621_REG_CONF
);
309 data
->conf
&= ~DS1621_REG_CONFIG_RESOL
;
310 data
->conf
|= (resol
<< DS1621_REG_CONFIG_RESOL_SHIFT
);
311 i2c_smbus_write_byte_data(client
, DS1621_REG_CONF
, data
->conf
);
312 data
->update_interval
= ds1721_convrates
[resol
];
313 data
->zbits
= 7 - resol
;
314 mutex_unlock(&data
->update_lock
);
319 static DEVICE_ATTR_RO(alarms
);
320 static DEVICE_ATTR_RW(update_interval
);
322 static SENSOR_DEVICE_ATTR(temp1_input
, S_IRUGO
, show_temp
, NULL
, 0);
323 static SENSOR_DEVICE_ATTR(temp1_min
, S_IWUSR
| S_IRUGO
, show_temp
, set_temp
, 1);
324 static SENSOR_DEVICE_ATTR(temp1_max
, S_IWUSR
| S_IRUGO
, show_temp
, set_temp
, 2);
325 static SENSOR_DEVICE_ATTR(temp1_min_alarm
, S_IRUGO
, show_alarm
, NULL
,
326 DS1621_ALARM_TEMP_LOW
);
327 static SENSOR_DEVICE_ATTR(temp1_max_alarm
, S_IRUGO
, show_alarm
, NULL
,
328 DS1621_ALARM_TEMP_HIGH
);
330 static struct attribute
*ds1621_attributes
[] = {
331 &sensor_dev_attr_temp1_input
.dev_attr
.attr
,
332 &sensor_dev_attr_temp1_min
.dev_attr
.attr
,
333 &sensor_dev_attr_temp1_max
.dev_attr
.attr
,
334 &sensor_dev_attr_temp1_min_alarm
.dev_attr
.attr
,
335 &sensor_dev_attr_temp1_max_alarm
.dev_attr
.attr
,
336 &dev_attr_alarms
.attr
,
337 &dev_attr_update_interval
.attr
,
341 static umode_t
ds1621_attribute_visible(struct kobject
*kobj
,
342 struct attribute
*attr
, int index
)
344 struct device
*dev
= container_of(kobj
, struct device
, kobj
);
345 struct ds1621_data
*data
= dev_get_drvdata(dev
);
347 if (attr
== &dev_attr_update_interval
.attr
)
348 if (data
->kind
== ds1621
|| data
->kind
== ds1625
)
349 /* shhh, we're hiding update_interval */
354 static const struct attribute_group ds1621_group
= {
355 .attrs
= ds1621_attributes
,
356 .is_visible
= ds1621_attribute_visible
358 __ATTRIBUTE_GROUPS(ds1621
);
360 static int ds1621_probe(struct i2c_client
*client
,
361 const struct i2c_device_id
*id
)
363 struct ds1621_data
*data
;
364 struct device
*hwmon_dev
;
366 data
= devm_kzalloc(&client
->dev
, sizeof(struct ds1621_data
),
371 mutex_init(&data
->update_lock
);
373 data
->kind
= id
->driver_data
;
374 data
->client
= client
;
376 /* Initialize the DS1621 chip */
377 ds1621_init_client(data
, client
);
379 hwmon_dev
= devm_hwmon_device_register_with_groups(&client
->dev
,
382 return PTR_ERR_OR_ZERO(hwmon_dev
);
385 static const struct i2c_device_id ds1621_id
[] = {
386 { "ds1621", ds1621
},
387 { "ds1625", ds1625
},
388 { "ds1631", ds1631
},
389 { "ds1721", ds1721
},
390 { "ds1731", ds1731
},
393 MODULE_DEVICE_TABLE(i2c
, ds1621_id
);
395 /* This is the driver that will be inserted */
396 static struct i2c_driver ds1621_driver
= {
397 .class = I2C_CLASS_HWMON
,
401 .probe
= ds1621_probe
,
402 .id_table
= ds1621_id
,
405 module_i2c_driver(ds1621_driver
);
407 MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>");
408 MODULE_DESCRIPTION("DS1621 driver");
409 MODULE_LICENSE("GPL");