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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 <[email protected]>
6 * Jean Delvare <[email protected]>
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
23static 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
38static 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
55static 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
106static u16 update_intervals[] = { 16000, 8000, 4000, 2000, 1000, 500, 250, 125 };
107
108static 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
132static 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
147static 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
158static 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
183static 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
198static 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
236static 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
247static const struct hwmon_ops max1619_hwmon_ops = {
248 .is_visible = max1619_is_visible,
249 .read = max1619_read,
250 .write = max1619_write,
251};
252
253static 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 */
259static 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
290static 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
304static 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
316static 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
323static bool max1619_regmap_is_volatile(struct device *dev, unsigned int reg)
324{
325 return reg <= MAX1619_REG_STATUS;
326}
327
328static 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
333static 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
342static const struct regmap_bus max1619_regmap_bus = {
343 .reg_write = max1619_reg_write,
344 .reg_read = max1619_reg_read,
345};
346
347static 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
368static const struct i2c_device_id max1619_id[] = {
369 { .name = "max1619" },
370 { }
371};
372MODULE_DEVICE_TABLE(i2c, max1619_id);
373
374#ifdef CONFIG_OF
375static const struct of_device_id max1619_of_match[] = {
376 { .compatible = "maxim,max1619", },
377 {},
378};
379
380MODULE_DEVICE_TABLE(of, max1619_of_match);
381#endif
382
383static 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
395module_i2c_driver(max1619_driver);
396
397MODULE_AUTHOR("Oleksij Rempel <[email protected]>, Jean Delvare <[email protected]>");
398MODULE_DESCRIPTION("MAX1619 sensor driver");
399MODULE_LICENSE("GPL");