1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * ds620.c - Support for temperature sensor and thermostat DS620
4 *
5 * Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de>
6 *
7 * based on ds1621.c by Christian W. Zuckschwerdt <zany@triq.net>
8 */
9
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/slab.h>
13 #include <linux/jiffies.h>
14 #include <linux/i2c.h>
15 #include <linux/hwmon.h>
16 #include <linux/hwmon-sysfs.h>
17 #include <linux/err.h>
18 #include <linux/mutex.h>
19 #include <linux/sysfs.h>
20 #include <linux/platform_data/ds620.h>
21
22 /*
23 * Many DS620 constants specified below
24 * 15 14 13 12 11 10 09 08
25 * |Done|NVB |THF |TLF |R1 |R0 |AUTOC|1SHOT|
26 *
27 * 07 06 05 04 03 02 01 00
28 * |PO2 |PO1 |A2 |A1 |A0 | | | |
29 */
30 #define DS620_REG_CONFIG_DONE 0x8000
31 #define DS620_REG_CONFIG_NVB 0x4000
32 #define DS620_REG_CONFIG_THF 0x2000
33 #define DS620_REG_CONFIG_TLF 0x1000
34 #define DS620_REG_CONFIG_R1 0x0800
35 #define DS620_REG_CONFIG_R0 0x0400
36 #define DS620_REG_CONFIG_AUTOC 0x0200
37 #define DS620_REG_CONFIG_1SHOT 0x0100
38 #define DS620_REG_CONFIG_PO2 0x0080
39 #define DS620_REG_CONFIG_PO1 0x0040
40 #define DS620_REG_CONFIG_A2 0x0020
41 #define DS620_REG_CONFIG_A1 0x0010
42 #define DS620_REG_CONFIG_A0 0x0008
43
44 /* The DS620 registers */
45 static const u8 DS620_REG_TEMP[3] = {
46 0xAA, /* input, word, RO */
47 0xA2, /* min, word, RW */
48 0xA0, /* max, word, RW */
49 };
50
51 #define DS620_REG_CONF 0xAC /* word, RW */
52 #define DS620_COM_START 0x51 /* no data */
53 #define DS620_COM_STOP 0x22 /* no data */
54
55 /* Each client has this additional data */
56 struct ds620_data {
57 struct i2c_client *client;
58 struct mutex update_lock;
59 bool valid; /* true if following fields are valid */
60 unsigned long last_updated; /* In jiffies */
61
62 s16 temp[3]; /* Register values, word */
63 };
64
ds620_init_client(struct i2c_client * client)65 static void ds620_init_client(struct i2c_client *client)
66 {
67 struct ds620_platform_data *ds620_info = dev_get_platdata(&client->dev);
68 u16 conf, new_conf;
69
70 new_conf = conf =
71 i2c_smbus_read_word_swapped(client, DS620_REG_CONF);
72
73 /* switch to continuous conversion mode */
74 new_conf &= ~DS620_REG_CONFIG_1SHOT;
75 /* already high at power-on, but don't trust the BIOS! */
76 new_conf |= DS620_REG_CONFIG_PO2;
77 /* thermostat mode according to platform data */
78 if (ds620_info && ds620_info->pomode == 1)
79 new_conf &= ~DS620_REG_CONFIG_PO1; /* PO_LOW */
80 else if (ds620_info && ds620_info->pomode == 2)
81 new_conf |= DS620_REG_CONFIG_PO1; /* PO_HIGH */
82 else
83 new_conf &= ~DS620_REG_CONFIG_PO2; /* always low */
84 /* with highest precision */
85 new_conf |= DS620_REG_CONFIG_R1 | DS620_REG_CONFIG_R0;
86
87 if (conf != new_conf)
88 i2c_smbus_write_word_swapped(client, DS620_REG_CONF, new_conf);
89
90 /* start conversion */
91 i2c_smbus_write_byte(client, DS620_COM_START);
92 }
93
ds620_update_client(struct device * dev)94 static struct ds620_data *ds620_update_client(struct device *dev)
95 {
96 struct ds620_data *data = dev_get_drvdata(dev);
97 struct i2c_client *client = data->client;
98 struct ds620_data *ret = data;
99
100 mutex_lock(&data->update_lock);
101
102 if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
103 || !data->valid) {
104 int i;
105 int res;
106
107 dev_dbg(&client->dev, "Starting ds620 update\n");
108
109 for (i = 0; i < ARRAY_SIZE(data->temp); i++) {
110 res = i2c_smbus_read_word_swapped(client,
111 DS620_REG_TEMP[i]);
112 if (res < 0) {
113 ret = ERR_PTR(res);
114 goto abort;
115 }
116
117 data->temp[i] = res;
118 }
119
120 data->last_updated = jiffies;
121 data->valid = true;
122 }
123 abort:
124 mutex_unlock(&data->update_lock);
125
126 return ret;
127 }
128
temp_show(struct device * dev,struct device_attribute * da,char * buf)129 static ssize_t temp_show(struct device *dev, struct device_attribute *da,
130 char *buf)
131 {
132 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
133 struct ds620_data *data = ds620_update_client(dev);
134
135 if (IS_ERR(data))
136 return PTR_ERR(data);
137
138 return sprintf(buf, "%d\n", ((data->temp[attr->index] / 8) * 625) / 10);
139 }
140
temp_store(struct device * dev,struct device_attribute * da,const char * buf,size_t count)141 static ssize_t temp_store(struct device *dev, struct device_attribute *da,
142 const char *buf, size_t count)
143 {
144 int res;
145 long val;
146
147 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
148 struct ds620_data *data = dev_get_drvdata(dev);
149 struct i2c_client *client = data->client;
150
151 res = kstrtol(buf, 10, &val);
152
153 if (res)
154 return res;
155
156 val = (clamp_val(val, -128000, 128000) * 10 / 625) * 8;
157
158 mutex_lock(&data->update_lock);
159 data->temp[attr->index] = val;
160 i2c_smbus_write_word_swapped(client, DS620_REG_TEMP[attr->index],
161 data->temp[attr->index]);
162 mutex_unlock(&data->update_lock);
163 return count;
164 }
165
alarm_show(struct device * dev,struct device_attribute * da,char * buf)166 static ssize_t alarm_show(struct device *dev, struct device_attribute *da,
167 char *buf)
168 {
169 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
170 struct ds620_data *data = ds620_update_client(dev);
171 struct i2c_client *client;
172 u16 conf, new_conf;
173 int res;
174
175 if (IS_ERR(data))
176 return PTR_ERR(data);
177
178 client = data->client;
179
180 /* reset alarms if necessary */
181 res = i2c_smbus_read_word_swapped(client, DS620_REG_CONF);
182 if (res < 0)
183 return res;
184
185 new_conf = conf = res;
186 new_conf &= ~attr->index;
187 if (conf != new_conf) {
188 res = i2c_smbus_write_word_swapped(client, DS620_REG_CONF,
189 new_conf);
190 if (res < 0)
191 return res;
192 }
193
194 return sprintf(buf, "%d\n", !!(conf & attr->index));
195 }
196
197 static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0);
198 static SENSOR_DEVICE_ATTR_RW(temp1_min, temp, 1);
199 static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, 2);
200 static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, alarm, DS620_REG_CONFIG_TLF);
201 static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, DS620_REG_CONFIG_THF);
202
203 static struct attribute *ds620_attrs[] = {
204 &sensor_dev_attr_temp1_input.dev_attr.attr,
205 &sensor_dev_attr_temp1_min.dev_attr.attr,
206 &sensor_dev_attr_temp1_max.dev_attr.attr,
207 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
208 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
209 NULL
210 };
211
212 ATTRIBUTE_GROUPS(ds620);
213
ds620_probe(struct i2c_client * client)214 static int ds620_probe(struct i2c_client *client)
215 {
216 struct device *dev = &client->dev;
217 struct device *hwmon_dev;
218 struct ds620_data *data;
219
220 data = devm_kzalloc(dev, sizeof(struct ds620_data), GFP_KERNEL);
221 if (!data)
222 return -ENOMEM;
223
224 data->client = client;
225 mutex_init(&data->update_lock);
226
227 /* Initialize the DS620 chip */
228 ds620_init_client(client);
229
230 hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
231 data, ds620_groups);
232 return PTR_ERR_OR_ZERO(hwmon_dev);
233 }
234
235 static const struct i2c_device_id ds620_id[] = {
236 {"ds620", 0},
237 {}
238 };
239
240 MODULE_DEVICE_TABLE(i2c, ds620_id);
241
242 /* This is the driver that will be inserted */
243 static struct i2c_driver ds620_driver = {
244 .class = I2C_CLASS_HWMON,
245 .driver = {
246 .name = "ds620",
247 },
248 .probe_new = ds620_probe,
249 .id_table = ds620_id,
250 };
251
252 module_i2c_driver(ds620_driver);
253
254 MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
255 MODULE_DESCRIPTION("DS620 driver");
256 MODULE_LICENSE("GPL");
257
