1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * max1619.c - Part of lm_sensors, Linux kernel modules for hardware
4  *             monitoring
5  * Copyright (C) 2003-2004 Oleksij Rempel <bug-track@fisher-privat.net>
6  *                         Jean Delvare <jdelvare@suse.de>
7  *
8  * Based on the lm90 driver. The MAX1619 is a sensor chip made by Maxim.
9  * It reports up to two temperatures (its own plus up to
10  * one external one). Complete datasheet can be
11  * obtained from Maxim's website at:
12  *   http://pdfserv.maxim-ic.com/en/ds/MAX1619.pdf
13  */
14 
15 #include <linux/err.h>
16 #include <linux/hwmon.h>
17 #include <linux/i2c.h>
18 #include <linux/init.h>
19 #include <linux/module.h>
20 #include <linux/regmap.h>
21 #include <linux/util_macros.h>
22 
23 static const unsigned short normal_i2c[] = {
24 	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
25 
26 #define MAX1619_REG_LOCAL_TEMP		0x00
27 #define MAX1619_REG_REMOTE_TEMP		0x01
28 #define MAX1619_REG_STATUS		0x02
29 #define MAX1619_REG_CONFIG		0x03
30 #define MAX1619_REG_CONVRATE		0x04
31 #define MAX1619_REG_REMOTE_HIGH		0x07
32 #define MAX1619_REG_REMOTE_LOW		0x08
33 #define MAX1619_REG_REMOTE_CRIT		0x10
34 #define MAX1619_REG_REMOTE_CRIT_HYST	0x11
35 #define MAX1619_REG_MAN_ID		0xFE
36 #define MAX1619_REG_CHIP_ID		0xFF
37 
get_alarms(struct regmap * regmap)38 static int get_alarms(struct regmap *regmap)
39 {
40 	static u32 regs[2] = { MAX1619_REG_STATUS, MAX1619_REG_CONFIG };
41 	u8 regdata[2];
42 	int ret;
43 
44 	ret = regmap_multi_reg_read(regmap, regs, regdata, 2);
45 	if (ret)
46 		return ret;
47 
48 	/* OVERT status bit may be reversed */
49 	if (!(regdata[1] & 0x20))
50 		regdata[0] ^= 0x02;
51 
52 	return regdata[0] & 0x1e;
53 }
54 
max1619_temp_read(struct regmap * regmap,u32 attr,int channel,long * val)55 static int max1619_temp_read(struct regmap *regmap, u32 attr, int channel, long *val)
56 {
57 	int reg = -1, alarm_bit = 0;
58 	u32 temp;
59 	int ret;
60 
61 	switch (attr) {
62 	case hwmon_temp_input:
63 		reg = channel ? MAX1619_REG_REMOTE_TEMP : MAX1619_REG_LOCAL_TEMP;
64 		break;
65 	case hwmon_temp_min:
66 		reg = MAX1619_REG_REMOTE_LOW;
67 		break;
68 	case hwmon_temp_max:
69 		reg = MAX1619_REG_REMOTE_HIGH;
70 		break;
71 	case hwmon_temp_crit:
72 		reg = MAX1619_REG_REMOTE_CRIT;
73 		break;
74 	case hwmon_temp_crit_hyst:
75 		reg = MAX1619_REG_REMOTE_CRIT_HYST;
76 		break;
77 	case hwmon_temp_min_alarm:
78 		alarm_bit = 3;
79 		break;
80 	case hwmon_temp_max_alarm:
81 		alarm_bit = 4;
82 		break;
83 	case hwmon_temp_crit_alarm:
84 		alarm_bit = 1;
85 		break;
86 	case hwmon_temp_fault:
87 		alarm_bit = 2;
88 		break;
89 	default:
90 		return -EOPNOTSUPP;
91 	}
92 	if (reg >= 0) {
93 		ret = regmap_read(regmap, reg, &temp);
94 		if (ret < 0)
95 			return ret;
96 		*val = sign_extend32(temp, 7) * 1000;
97 	} else {
98 		ret = get_alarms(regmap);
99 		if (ret < 0)
100 			return ret;
101 		*val = !!(ret & BIT(alarm_bit));
102 	}
103 	return 0;
104 }
105 
106 static u16 update_intervals[] = { 16000, 8000, 4000, 2000, 1000, 500, 250, 125 };
107 
max1619_chip_read(struct regmap * regmap,u32 attr,long * val)108 static int max1619_chip_read(struct regmap *regmap, u32 attr, long *val)
109 {
110 	int alarms, ret;
111 	u32 regval;
112 
113 	switch (attr) {
114 	case hwmon_chip_update_interval:
115 		ret = regmap_read(regmap, MAX1619_REG_CONVRATE, &regval);
116 		if (ret < 0)
117 			return ret;
118 		*val = update_intervals[regval & 7];
119 		break;
120 	case hwmon_chip_alarms:
121 		alarms = get_alarms(regmap);
122 		if (alarms < 0)
123 			return alarms;
124 		*val = alarms;
125 		break;
126 	default:
127 		return -EOPNOTSUPP;
128 	}
129 	return 0;
130 }
131 
max1619_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)132 static int max1619_read(struct device *dev, enum hwmon_sensor_types type,
133 			u32 attr, int channel, long *val)
134 {
135 	struct regmap *regmap = dev_get_drvdata(dev);
136 
137 	switch (type) {
138 	case hwmon_chip:
139 		return max1619_chip_read(regmap, attr, val);
140 	case hwmon_temp:
141 		return max1619_temp_read(regmap, attr, channel, val);
142 	default:
143 		return -EOPNOTSUPP;
144 	}
145 }
146 
max1619_chip_write(struct regmap * regmap,u32 attr,long val)147 static int max1619_chip_write(struct regmap *regmap, u32 attr, long val)
148 {
149 	switch (attr) {
150 	case hwmon_chip_update_interval:
151 		val = find_closest_descending(val, update_intervals, ARRAY_SIZE(update_intervals));
152 		return regmap_write(regmap, MAX1619_REG_CONVRATE, val);
153 	default:
154 		return -EOPNOTSUPP;
155 	}
156 }
157 
max1619_temp_write(struct regmap * regmap,u32 attr,int channel,long val)158 static int max1619_temp_write(struct regmap *regmap,
159 			      u32 attr, int channel, long val)
160 {
161 	int reg;
162 
163 	switch (attr) {
164 	case hwmon_temp_min:
165 		reg = MAX1619_REG_REMOTE_LOW;
166 		break;
167 	case hwmon_temp_max:
168 		reg = MAX1619_REG_REMOTE_HIGH;
169 		break;
170 	case hwmon_temp_crit:
171 		reg = MAX1619_REG_REMOTE_CRIT;
172 		break;
173 	case hwmon_temp_crit_hyst:
174 		reg = MAX1619_REG_REMOTE_CRIT_HYST;
175 		break;
176 	default:
177 		return -EOPNOTSUPP;
178 	}
179 	val = DIV_ROUND_CLOSEST(clamp_val(val, -128000, 127000), 1000);
180 	return regmap_write(regmap, reg, val);
181 }
182 
max1619_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)183 static int max1619_write(struct device *dev, enum hwmon_sensor_types type,
184 			 u32 attr, int channel, long val)
185 {
186 	struct regmap *regmap = dev_get_drvdata(dev);
187 
188 	switch (type) {
189 	case hwmon_chip:
190 		return max1619_chip_write(regmap, attr, val);
191 	case hwmon_temp:
192 		return max1619_temp_write(regmap, attr, channel, val);
193 	default:
194 		return -EOPNOTSUPP;
195 	}
196 }
197 
max1619_is_visible(const void * _data,enum hwmon_sensor_types type,u32 attr,int channel)198 static umode_t max1619_is_visible(const void *_data, enum hwmon_sensor_types type,
199 				  u32 attr, int channel)
200 {
201 	switch (type) {
202 	case hwmon_chip:
203 		switch (attr) {
204 		case hwmon_chip_update_interval:
205 			return 0644;
206 		case hwmon_chip_alarms:
207 			return 0444;
208 		default:
209 			break;
210 		}
211 		break;
212 	case hwmon_temp:
213 		switch (attr) {
214 		case hwmon_temp_input:
215 			return 0444;
216 		case hwmon_temp_min:
217 		case hwmon_temp_max:
218 		case hwmon_temp_crit:
219 		case hwmon_temp_crit_hyst:
220 			return 0644;
221 		case hwmon_temp_min_alarm:
222 		case hwmon_temp_max_alarm:
223 		case hwmon_temp_crit_alarm:
224 		case hwmon_temp_fault:
225 			return 0444;
226 		default:
227 			break;
228 		}
229 		break;
230 	default:
231 		break;
232 	}
233 	return 0;
234 }
235 
236 static const struct hwmon_channel_info * const max1619_info[] = {
237 	HWMON_CHANNEL_INFO(chip, HWMON_C_ALARMS | HWMON_C_UPDATE_INTERVAL),
238 	HWMON_CHANNEL_INFO(temp,
239 			   HWMON_T_INPUT,
240 			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
241 			   HWMON_T_CRIT | HWMON_T_CRIT_HYST |
242 			   HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM |
243 			   HWMON_T_CRIT_ALARM | HWMON_T_FAULT),
244 	NULL
245 };
246 
247 static const struct hwmon_ops max1619_hwmon_ops = {
248 	.is_visible = max1619_is_visible,
249 	.read = max1619_read,
250 	.write = max1619_write,
251 };
252 
253 static const struct hwmon_chip_info max1619_chip_info = {
254 	.ops = &max1619_hwmon_ops,
255 	.info = max1619_info,
256 };
257 
258 /* Return 0 if detection is successful, -ENODEV otherwise */
max1619_detect(struct i2c_client * client,struct i2c_board_info * info)259 static int max1619_detect(struct i2c_client *client,
260 			  struct i2c_board_info *info)
261 {
262 	struct i2c_adapter *adapter = client->adapter;
263 	int regval;
264 
265 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
266 		return -ENODEV;
267 
268 	regval = i2c_smbus_read_byte_data(client, MAX1619_REG_CONFIG);
269 	if (regval < 0 || (regval & 0x03))
270 		return -ENODEV;
271 	regval = i2c_smbus_read_byte_data(client, MAX1619_REG_CONVRATE);
272 	if (regval < 0 || regval > 0x07)
273 		return -ENODEV;
274 	regval = i2c_smbus_read_byte_data(client, MAX1619_REG_STATUS);
275 	if (regval < 0 || (regval & 0x61))
276 		return -ENODEV;
277 
278 	regval = i2c_smbus_read_byte_data(client, MAX1619_REG_MAN_ID);
279 	if (regval != 0x4d)
280 		return -ENODEV;
281 	regval = i2c_smbus_read_byte_data(client, MAX1619_REG_CHIP_ID);
282 	if (regval != 0x04)
283 		return -ENODEV;
284 
285 	strscpy(info->type, "max1619", I2C_NAME_SIZE);
286 
287 	return 0;
288 }
289 
max1619_init_chip(struct regmap * regmap)290 static int max1619_init_chip(struct regmap *regmap)
291 {
292 	int ret;
293 
294 	ret = regmap_write(regmap, MAX1619_REG_CONVRATE, 5);	/* 2 Hz */
295 	if (ret)
296 		return ret;
297 
298 	/* Start conversions */
299 	return regmap_clear_bits(regmap, MAX1619_REG_CONFIG, 0x40);
300 }
301 
302 /* regmap */
303 
max1619_reg_read(void * context,unsigned int reg,unsigned int * val)304 static int max1619_reg_read(void *context, unsigned int reg, unsigned int *val)
305 {
306 	int ret;
307 
308 	ret = i2c_smbus_read_byte_data(context, reg);
309 	if (ret < 0)
310 		return ret;
311 
312 	*val = ret;
313 	return 0;
314 }
315 
max1619_reg_write(void * context,unsigned int reg,unsigned int val)316 static int max1619_reg_write(void *context, unsigned int reg, unsigned int val)
317 {
318 	int offset = reg < MAX1619_REG_REMOTE_CRIT ? 6 : 2;
319 
320 	return i2c_smbus_write_byte_data(context, reg + offset, val);
321 }
322 
max1619_regmap_is_volatile(struct device * dev,unsigned int reg)323 static bool max1619_regmap_is_volatile(struct device *dev, unsigned int reg)
324 {
325 	return reg <= MAX1619_REG_STATUS;
326 }
327 
max1619_regmap_is_writeable(struct device * dev,unsigned int reg)328 static bool max1619_regmap_is_writeable(struct device *dev, unsigned int reg)
329 {
330 	return reg > MAX1619_REG_STATUS && reg <= MAX1619_REG_REMOTE_CRIT_HYST;
331 }
332 
333 static const struct regmap_config max1619_regmap_config = {
334 	.reg_bits = 8,
335 	.val_bits = 8,
336 	.max_register = MAX1619_REG_REMOTE_CRIT_HYST,
337 	.cache_type = REGCACHE_MAPLE,
338 	.volatile_reg = max1619_regmap_is_volatile,
339 	.writeable_reg = max1619_regmap_is_writeable,
340 };
341 
342 static const struct regmap_bus max1619_regmap_bus = {
343 	.reg_write = max1619_reg_write,
344 	.reg_read = max1619_reg_read,
345 };
346 
max1619_probe(struct i2c_client * client)347 static int max1619_probe(struct i2c_client *client)
348 {
349 	struct device *dev = &client->dev;
350 	struct device *hwmon_dev;
351 	struct regmap *regmap;
352 	int ret;
353 
354 	regmap = devm_regmap_init(dev, &max1619_regmap_bus, client,
355 				  &max1619_regmap_config);
356 	if (IS_ERR(regmap))
357 		return PTR_ERR(regmap);
358 
359 	ret = max1619_init_chip(regmap);
360 	if (ret)
361 		return ret;
362 
363 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
364 							 regmap, &max1619_chip_info, NULL);
365 	return PTR_ERR_OR_ZERO(hwmon_dev);
366 }
367 
368 static const struct i2c_device_id max1619_id[] = {
369 	{ "max1619" },
370 	{ }
371 };
372 MODULE_DEVICE_TABLE(i2c, max1619_id);
373 
374 #ifdef CONFIG_OF
375 static const struct of_device_id max1619_of_match[] = {
376 	{ .compatible = "maxim,max1619", },
377 	{},
378 };
379 
380 MODULE_DEVICE_TABLE(of, max1619_of_match);
381 #endif
382 
383 static struct i2c_driver max1619_driver = {
384 	.class		= I2C_CLASS_HWMON,
385 	.driver = {
386 		.name	= "max1619",
387 		.of_match_table = of_match_ptr(max1619_of_match),
388 	},
389 	.probe		= max1619_probe,
390 	.id_table	= max1619_id,
391 	.detect		= max1619_detect,
392 	.address_list	= normal_i2c,
393 };
394 
395 module_i2c_driver(max1619_driver);
396 
397 MODULE_AUTHOR("Oleksij Rempel <bug-track@fisher-privat.net>, Jean Delvare <jdelvare@suse.de>");
398 MODULE_DESCRIPTION("MAX1619 sensor driver");
399 MODULE_LICENSE("GPL");
400