xref: /linux/drivers/hwmon/w83773g.c (revision 79790b6818e96c58fe2bffee1b418c16e64e7b80)
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 
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, &regval);
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], &regval_high);
81 	if (ret < 0)
82 		return ret;
83 
84 	ret = regmap_read(regmap, W83773_TEMP_LSB[index], &regval_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], &regval);
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], &regval_high);
112 	if (ret < 0)
113 		return ret;
114 
115 	ret = regmap_read(regmap, W83773_OFFSET_LSB[index], &regval_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, &regval);
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 * 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 
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 	.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