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.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 | |
51 | static inline long temp_of_local(s8 reg) |
52 | { |
53 | return reg * 1000; |
54 | } |
55 | |
56 | static inline long temp_of_remote(s8 hb, u8 lb) |
57 | { |
58 | return (hb << 3 | lb >> 5) * 125; |
59 | } |
60 | |
61 | static int get_local_temp(struct regmap *regmap, long *val) |
62 | { |
63 | unsigned int regval; |
64 | int ret; |
65 | |
66 | ret = regmap_read(map: regmap, W83773_LOCAL_TEMP, val: ®val); |
67 | if (ret < 0) |
68 | return ret; |
69 | |
70 | *val = temp_of_local(reg: regval); |
71 | return 0; |
72 | } |
73 | |
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(map: regmap, reg: W83773_TEMP_MSB[index], val: ®val_high); |
81 | if (ret < 0) |
82 | return ret; |
83 | |
84 | ret = regmap_read(map: regmap, reg: W83773_TEMP_LSB[index], val: ®val_low); |
85 | if (ret < 0) |
86 | return ret; |
87 | |
88 | *val = temp_of_remote(hb: regval_high, lb: regval_low); |
89 | return 0; |
90 | } |
91 | |
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(map: regmap, reg: W83773_STATUS[index], val: ®val); |
98 | if (ret < 0) |
99 | return ret; |
100 | |
101 | *val = (regval & 0x04) >> 2; |
102 | return 0; |
103 | } |
104 | |
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(map: regmap, reg: W83773_OFFSET_MSB[index], val: ®val_high); |
112 | if (ret < 0) |
113 | return ret; |
114 | |
115 | ret = regmap_read(map: regmap, reg: W83773_OFFSET_LSB[index], val: ®val_low); |
116 | if (ret < 0) |
117 | return ret; |
118 | |
119 | *val = temp_of_remote(hb: regval_high, lb: regval_low); |
120 | return 0; |
121 | } |
122 | |
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(map: regmap, reg: W83773_OFFSET_MSB[index], val: high_byte); |
136 | if (ret < 0) |
137 | return ret; |
138 | |
139 | return regmap_write(map: regmap, reg: W83773_OFFSET_LSB[index], val: low_byte); |
140 | } |
141 | |
142 | static int get_update_interval(struct regmap *regmap, long *val) |
143 | { |
144 | unsigned int regval; |
145 | int ret; |
146 | |
147 | ret = regmap_read(map: regmap, W83773_CONVERSION_RATE_REG_READ, val: ®val); |
148 | if (ret < 0) |
149 | return ret; |
150 | |
151 | *val = 16000 >> regval; |
152 | return 0; |
153 | } |
154 | |
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(word: (val * 8 / (625 * 7))); |
169 | return regmap_write(map: regmap, W83773_CONVERSION_RATE_REG_WRITE, val: rate); |
170 | } |
171 | |
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, index: channel - 1, val); |
188 | case hwmon_temp_fault: |
189 | return get_fault(regmap, index: channel - 1, val); |
190 | case hwmon_temp_offset: |
191 | return get_offset(regmap, index: channel - 1, val); |
192 | default: |
193 | return -EOPNOTSUPP; |
194 | } |
195 | } |
196 | |
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, index: channel - 1, val); |
207 | |
208 | return -EOPNOTSUPP; |
209 | } |
210 | |
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 * const 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 | |
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(ptr: regmap)) { |
271 | dev_err(dev, "failed to allocate register map\n" ); |
272 | return PTR_ERR(ptr: regmap); |
273 | } |
274 | |
275 | /* Set the conversion rate to 2 Hz */ |
276 | ret = regmap_write(map: regmap, W83773_CONVERSION_RATE_REG_WRITE, val: 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, data: regmap); |
283 | |
284 | hwmon_dev = devm_hwmon_device_register_with_info(dev, |
285 | name: client->name, |
286 | drvdata: regmap, |
287 | info: &w83773_chip_info, |
288 | NULL); |
289 | return PTR_ERR_OR_ZERO(ptr: hwmon_dev); |
290 | } |
291 | |
292 | static struct i2c_driver w83773_driver = { |
293 | .driver = { |
294 | .name = "w83773g" , |
295 | .of_match_table = of_match_ptr(w83773_of_match), |
296 | }, |
297 | .probe = w83773_probe, |
298 | .id_table = w83773_id, |
299 | }; |
300 | |
301 | module_i2c_driver(w83773_driver); |
302 | |
303 | MODULE_AUTHOR("Lei YU <mine260309@gmail.com>" ); |
304 | MODULE_DESCRIPTION("W83773G temperature sensor driver" ); |
305 | MODULE_LICENSE("GPL" ); |
306 | |