1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2017 IBM Corp.
4 *
5 * Driver for the Nuvoton W83773G SMBus temperature sensor IC.
6 * Supported models: W83773G
7 */
8
9 #include <linux/module.h>
10 #include <linux/init.h>
11 #include <linux/i2c.h>
12 #include <linux/hwmon.h>
13 #include <linux/hwmon-sysfs.h>
14 #include <linux/err.h>
15 #include <linux/of_device.h>
16 #include <linux/regmap.h>
17
18 /* W83773 has 3 channels */
19 #define W83773_CHANNELS 3
20
21 /* The W83773 registers */
22 #define W83773_CONVERSION_RATE_REG_READ 0x04
23 #define W83773_CONVERSION_RATE_REG_WRITE 0x0A
24 #define W83773_MANUFACTURER_ID_REG 0xFE
25 #define W83773_LOCAL_TEMP 0x00
26
27 static const u8 W83773_STATUS[2] = { 0x02, 0x17 };
28
29 static const u8 W83773_TEMP_LSB[2] = { 0x10, 0x25 };
30 static const u8 W83773_TEMP_MSB[2] = { 0x01, 0x24 };
31
32 static const u8 W83773_OFFSET_LSB[2] = { 0x12, 0x16 };
33 static const u8 W83773_OFFSET_MSB[2] = { 0x11, 0x15 };
34
35 /* this is the number of sensors in the device */
36 static const struct i2c_device_id w83773_id[] = {
37 { "w83773g" },
38 { }
39 };
40
41 MODULE_DEVICE_TABLE(i2c, w83773_id);
42
43 static const struct of_device_id __maybe_unused w83773_of_match[] = {
44 {
45 .compatible = "nuvoton,w83773g"
46 },
47 { },
48 };
49 MODULE_DEVICE_TABLE(of, w83773_of_match);
50
temp_of_local(s8 reg)51 static inline long temp_of_local(s8 reg)
52 {
53 return reg * 1000;
54 }
55
temp_of_remote(s8 hb,u8 lb)56 static inline long temp_of_remote(s8 hb, u8 lb)
57 {
58 return (hb << 3 | lb >> 5) * 125;
59 }
60
get_local_temp(struct regmap * regmap,long * val)61 static int get_local_temp(struct regmap *regmap, long *val)
62 {
63 unsigned int regval;
64 int ret;
65
66 ret = regmap_read(regmap, W83773_LOCAL_TEMP, ®val);
67 if (ret < 0)
68 return ret;
69
70 *val = temp_of_local(regval);
71 return 0;
72 }
73
get_remote_temp(struct regmap * regmap,int index,long * val)74 static int get_remote_temp(struct regmap *regmap, int index, long *val)
75 {
76 unsigned int regval_high;
77 unsigned int regval_low;
78 int ret;
79
80 ret = regmap_read(regmap, W83773_TEMP_MSB[index], ®val_high);
81 if (ret < 0)
82 return ret;
83
84 ret = regmap_read(regmap, W83773_TEMP_LSB[index], ®val_low);
85 if (ret < 0)
86 return ret;
87
88 *val = temp_of_remote(regval_high, regval_low);
89 return 0;
90 }
91
get_fault(struct regmap * regmap,int index,long * val)92 static int get_fault(struct regmap *regmap, int index, long *val)
93 {
94 unsigned int regval;
95 int ret;
96
97 ret = regmap_read(regmap, W83773_STATUS[index], ®val);
98 if (ret < 0)
99 return ret;
100
101 *val = (regval & 0x04) >> 2;
102 return 0;
103 }
104
get_offset(struct regmap * regmap,int index,long * val)105 static int get_offset(struct regmap *regmap, int index, long *val)
106 {
107 unsigned int regval_high;
108 unsigned int regval_low;
109 int ret;
110
111 ret = regmap_read(regmap, W83773_OFFSET_MSB[index], ®val_high);
112 if (ret < 0)
113 return ret;
114
115 ret = regmap_read(regmap, W83773_OFFSET_LSB[index], ®val_low);
116 if (ret < 0)
117 return ret;
118
119 *val = temp_of_remote(regval_high, regval_low);
120 return 0;
121 }
122
set_offset(struct regmap * regmap,int index,long val)123 static int set_offset(struct regmap *regmap, int index, long val)
124 {
125 int ret;
126 u8 high_byte;
127 u8 low_byte;
128
129 val = clamp_val(val, -127825, 127825);
130 /* offset value equals to (high_byte << 3 | low_byte >> 5) * 125 */
131 val /= 125;
132 high_byte = val >> 3;
133 low_byte = (val & 0x07) << 5;
134
135 ret = regmap_write(regmap, W83773_OFFSET_MSB[index], high_byte);
136 if (ret < 0)
137 return ret;
138
139 return regmap_write(regmap, W83773_OFFSET_LSB[index], low_byte);
140 }
141
get_update_interval(struct regmap * regmap,long * val)142 static int get_update_interval(struct regmap *regmap, long *val)
143 {
144 unsigned int regval;
145 int ret;
146
147 ret = regmap_read(regmap, W83773_CONVERSION_RATE_REG_READ, ®val);
148 if (ret < 0)
149 return ret;
150
151 *val = 16000 >> regval;
152 return 0;
153 }
154
set_update_interval(struct regmap * regmap,long val)155 static int set_update_interval(struct regmap *regmap, long val)
156 {
157 int rate;
158
159 /*
160 * For valid rates, interval can be calculated as
161 * interval = (1 << (8 - rate)) * 62.5;
162 * Rounded rate is therefore
163 * rate = 8 - __fls(interval * 8 / (62.5 * 7));
164 * Use clamp_val() to avoid overflows, and to ensure valid input
165 * for __fls.
166 */
167 val = clamp_val(val, 62, 16000) * 10;
168 rate = 8 - __fls((val * 8 / (625 * 7)));
169 return regmap_write(regmap, W83773_CONVERSION_RATE_REG_WRITE, rate);
170 }
171
w83773_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)172 static int w83773_read(struct device *dev, enum hwmon_sensor_types type,
173 u32 attr, int channel, long *val)
174 {
175 struct regmap *regmap = dev_get_drvdata(dev);
176
177 if (type == hwmon_chip) {
178 if (attr == hwmon_chip_update_interval)
179 return get_update_interval(regmap, val);
180 return -EOPNOTSUPP;
181 }
182
183 switch (attr) {
184 case hwmon_temp_input:
185 if (channel == 0)
186 return get_local_temp(regmap, val);
187 return get_remote_temp(regmap, channel - 1, val);
188 case hwmon_temp_fault:
189 return get_fault(regmap, channel - 1, val);
190 case hwmon_temp_offset:
191 return get_offset(regmap, channel - 1, val);
192 default:
193 return -EOPNOTSUPP;
194 }
195 }
196
w83773_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)197 static int w83773_write(struct device *dev, enum hwmon_sensor_types type,
198 u32 attr, int channel, long val)
199 {
200 struct regmap *regmap = dev_get_drvdata(dev);
201
202 if (type == hwmon_chip && attr == hwmon_chip_update_interval)
203 return set_update_interval(regmap, val);
204
205 if (type == hwmon_temp && attr == hwmon_temp_offset)
206 return set_offset(regmap, channel - 1, val);
207
208 return -EOPNOTSUPP;
209 }
210
w83773_is_visible(const void * data,enum hwmon_sensor_types type,u32 attr,int channel)211 static umode_t w83773_is_visible(const void *data, enum hwmon_sensor_types type,
212 u32 attr, int channel)
213 {
214 switch (type) {
215 case hwmon_chip:
216 switch (attr) {
217 case hwmon_chip_update_interval:
218 return 0644;
219 }
220 break;
221 case hwmon_temp:
222 switch (attr) {
223 case hwmon_temp_input:
224 case hwmon_temp_fault:
225 return 0444;
226 case hwmon_temp_offset:
227 return 0644;
228 }
229 break;
230 default:
231 break;
232 }
233 return 0;
234 }
235
236 static const struct hwmon_channel_info *w83773_info[] = {
237 HWMON_CHANNEL_INFO(chip,
238 HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL),
239 HWMON_CHANNEL_INFO(temp,
240 HWMON_T_INPUT,
241 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_OFFSET,
242 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_OFFSET),
243 NULL
244 };
245
246 static const struct hwmon_ops w83773_ops = {
247 .is_visible = w83773_is_visible,
248 .read = w83773_read,
249 .write = w83773_write,
250 };
251
252 static const struct hwmon_chip_info w83773_chip_info = {
253 .ops = &w83773_ops,
254 .info = w83773_info,
255 };
256
257 static const struct regmap_config w83773_regmap_config = {
258 .reg_bits = 8,
259 .val_bits = 8,
260 };
261
w83773_probe(struct i2c_client * client)262 static int w83773_probe(struct i2c_client *client)
263 {
264 struct device *dev = &client->dev;
265 struct device *hwmon_dev;
266 struct regmap *regmap;
267 int ret;
268
269 regmap = devm_regmap_init_i2c(client, &w83773_regmap_config);
270 if (IS_ERR(regmap)) {
271 dev_err(dev, "failed to allocate register map\n");
272 return PTR_ERR(regmap);
273 }
274
275 /* Set the conversion rate to 2 Hz */
276 ret = regmap_write(regmap, W83773_CONVERSION_RATE_REG_WRITE, 0x05);
277 if (ret < 0) {
278 dev_err(&client->dev, "error writing config rate register\n");
279 return ret;
280 }
281
282 i2c_set_clientdata(client, regmap);
283
284 hwmon_dev = devm_hwmon_device_register_with_info(dev,
285 client->name,
286 regmap,
287 &w83773_chip_info,
288 NULL);
289 return PTR_ERR_OR_ZERO(hwmon_dev);
290 }
291
292 static struct i2c_driver w83773_driver = {
293 .class = I2C_CLASS_HWMON,
294 .driver = {
295 .name = "w83773g",
296 .of_match_table = of_match_ptr(w83773_of_match),
297 },
298 .probe_new = w83773_probe,
299 .id_table = w83773_id,
300 };
301
302 module_i2c_driver(w83773_driver);
303
304 MODULE_AUTHOR("Lei YU <mine260309@gmail.com>");
305 MODULE_DESCRIPTION("W83773G temperature sensor driver");
306 MODULE_LICENSE("GPL");
307