Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma
[sfrench/cifs-2.6.git] / drivers / hwmon / ltc2945.c
1 /*
2  * Driver for Linear Technology LTC2945 I2C Power Monitor
3  *
4  * Copyright (c) 2014 Guenter Roeck
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  */
16
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/err.h>
20 #include <linux/slab.h>
21 #include <linux/i2c.h>
22 #include <linux/hwmon.h>
23 #include <linux/hwmon-sysfs.h>
24 #include <linux/jiffies.h>
25 #include <linux/regmap.h>
26
27 /* chip registers */
28 #define LTC2945_CONTROL                 0x00
29 #define LTC2945_ALERT                   0x01
30 #define LTC2945_STATUS                  0x02
31 #define LTC2945_FAULT                   0x03
32 #define LTC2945_POWER_H                 0x05
33 #define LTC2945_MAX_POWER_H             0x08
34 #define LTC2945_MIN_POWER_H             0x0b
35 #define LTC2945_MAX_POWER_THRES_H       0x0e
36 #define LTC2945_MIN_POWER_THRES_H       0x11
37 #define LTC2945_SENSE_H                 0x14
38 #define LTC2945_MAX_SENSE_H             0x16
39 #define LTC2945_MIN_SENSE_H             0x18
40 #define LTC2945_MAX_SENSE_THRES_H       0x1a
41 #define LTC2945_MIN_SENSE_THRES_H       0x1c
42 #define LTC2945_VIN_H                   0x1e
43 #define LTC2945_MAX_VIN_H               0x20
44 #define LTC2945_MIN_VIN_H               0x22
45 #define LTC2945_MAX_VIN_THRES_H         0x24
46 #define LTC2945_MIN_VIN_THRES_H         0x26
47 #define LTC2945_ADIN_H                  0x28
48 #define LTC2945_MAX_ADIN_H              0x2a
49 #define LTC2945_MIN_ADIN_H              0x2c
50 #define LTC2945_MAX_ADIN_THRES_H        0x2e
51 #define LTC2945_MIN_ADIN_THRES_H        0x30
52 #define LTC2945_MIN_ADIN_THRES_L        0x31
53
54 /* Fault register bits */
55
56 #define FAULT_ADIN_UV           (1 << 0)
57 #define FAULT_ADIN_OV           (1 << 1)
58 #define FAULT_VIN_UV            (1 << 2)
59 #define FAULT_VIN_OV            (1 << 3)
60 #define FAULT_SENSE_UV          (1 << 4)
61 #define FAULT_SENSE_OV          (1 << 5)
62 #define FAULT_POWER_UV          (1 << 6)
63 #define FAULT_POWER_OV          (1 << 7)
64
65 /* Control register bits */
66
67 #define CONTROL_MULT_SELECT     (1 << 0)
68 #define CONTROL_TEST_MODE       (1 << 4)
69
70 static inline bool is_power_reg(u8 reg)
71 {
72         return reg < LTC2945_SENSE_H;
73 }
74
75 /* Return the value from the given register in uW, mV, or mA */
76 static long long ltc2945_reg_to_val(struct device *dev, u8 reg)
77 {
78         struct regmap *regmap = dev_get_drvdata(dev);
79         unsigned int control;
80         u8 buf[3];
81         long long val;
82         int ret;
83
84         ret = regmap_bulk_read(regmap, reg, buf,
85                                is_power_reg(reg) ? 3 : 2);
86         if (ret < 0)
87                 return ret;
88
89         if (is_power_reg(reg)) {
90                 /* power */
91                 val = (buf[0] << 16) + (buf[1] << 8) + buf[2];
92         } else {
93                 /* current, voltage */
94                 val = (buf[0] << 4) + (buf[1] >> 4);
95         }
96
97         switch (reg) {
98         case LTC2945_POWER_H:
99         case LTC2945_MAX_POWER_H:
100         case LTC2945_MIN_POWER_H:
101         case LTC2945_MAX_POWER_THRES_H:
102         case LTC2945_MIN_POWER_THRES_H:
103                 /*
104                  * Convert to uW by assuming current is measured with
105                  * an 1mOhm sense resistor, similar to current
106                  * measurements.
107                  * Control register bit 0 selects if voltage at SENSE+/VDD
108                  * or voltage at ADIN is used to measure power.
109                  */
110                 ret = regmap_read(regmap, LTC2945_CONTROL, &control);
111                 if (ret < 0)
112                         return ret;
113                 if (control & CONTROL_MULT_SELECT) {
114                         /* 25 mV * 25 uV = 0.625 uV resolution. */
115                         val *= 625LL;
116                 } else {
117                         /* 0.5 mV * 25 uV = 0.0125 uV resolution. */
118                         val = (val * 25LL) >> 1;
119                 }
120                 break;
121         case LTC2945_VIN_H:
122         case LTC2945_MAX_VIN_H:
123         case LTC2945_MIN_VIN_H:
124         case LTC2945_MAX_VIN_THRES_H:
125         case LTC2945_MIN_VIN_THRES_H:
126                 /* 25 mV resolution. Convert to mV. */
127                 val *= 25;
128                 break;
129         case LTC2945_ADIN_H:
130         case LTC2945_MAX_ADIN_H:
131         case LTC2945_MIN_ADIN_THRES_H:
132         case LTC2945_MAX_ADIN_THRES_H:
133         case LTC2945_MIN_ADIN_H:
134                 /* 0.5mV resolution. Convert to mV. */
135                 val = val >> 1;
136                 break;
137         case LTC2945_SENSE_H:
138         case LTC2945_MAX_SENSE_H:
139         case LTC2945_MIN_SENSE_H:
140         case LTC2945_MAX_SENSE_THRES_H:
141         case LTC2945_MIN_SENSE_THRES_H:
142                 /*
143                  * 25 uV resolution. Convert to current as measured with
144                  * an 1 mOhm sense resistor, in mA. If a different sense
145                  * resistor is installed, calculate the actual current by
146                  * dividing the reported current by the sense resistor value
147                  * in mOhm.
148                  */
149                 val *= 25;
150                 break;
151         default:
152                 return -EINVAL;
153         }
154         return val;
155 }
156
157 static int ltc2945_val_to_reg(struct device *dev, u8 reg,
158                               unsigned long val)
159 {
160         struct regmap *regmap = dev_get_drvdata(dev);
161         unsigned int control;
162         int ret;
163
164         switch (reg) {
165         case LTC2945_POWER_H:
166         case LTC2945_MAX_POWER_H:
167         case LTC2945_MIN_POWER_H:
168         case LTC2945_MAX_POWER_THRES_H:
169         case LTC2945_MIN_POWER_THRES_H:
170                 /*
171                  * Convert to register value by assuming current is measured
172                  * with an 1mOhm sense resistor, similar to current
173                  * measurements.
174                  * Control register bit 0 selects if voltage at SENSE+/VDD
175                  * or voltage at ADIN is used to measure power, which in turn
176                  * determines register calculations.
177                  */
178                 ret = regmap_read(regmap, LTC2945_CONTROL, &control);
179                 if (ret < 0)
180                         return ret;
181                 if (control & CONTROL_MULT_SELECT) {
182                         /* 25 mV * 25 uV = 0.625 uV resolution. */
183                         val = DIV_ROUND_CLOSEST(val, 625);
184                 } else {
185                         /*
186                          * 0.5 mV * 25 uV = 0.0125 uV resolution.
187                          * Divide first to avoid overflow;
188                          * accept loss of accuracy.
189                          */
190                         val = DIV_ROUND_CLOSEST(val, 25) * 2;
191                 }
192                 break;
193         case LTC2945_VIN_H:
194         case LTC2945_MAX_VIN_H:
195         case LTC2945_MIN_VIN_H:
196         case LTC2945_MAX_VIN_THRES_H:
197         case LTC2945_MIN_VIN_THRES_H:
198                 /* 25 mV resolution. */
199                 val /= 25;
200                 break;
201         case LTC2945_ADIN_H:
202         case LTC2945_MAX_ADIN_H:
203         case LTC2945_MIN_ADIN_THRES_H:
204         case LTC2945_MAX_ADIN_THRES_H:
205         case LTC2945_MIN_ADIN_H:
206                 /* 0.5mV resolution. */
207                 val *= 2;
208                 break;
209         case LTC2945_SENSE_H:
210         case LTC2945_MAX_SENSE_H:
211         case LTC2945_MIN_SENSE_H:
212         case LTC2945_MAX_SENSE_THRES_H:
213         case LTC2945_MIN_SENSE_THRES_H:
214                 /*
215                  * 25 uV resolution. Convert to current as measured with
216                  * an 1 mOhm sense resistor, in mA. If a different sense
217                  * resistor is installed, calculate the actual current by
218                  * dividing the reported current by the sense resistor value
219                  * in mOhm.
220                  */
221                 val = DIV_ROUND_CLOSEST(val, 25);
222                 break;
223         default:
224                 return -EINVAL;
225         }
226         return val;
227 }
228
229 static ssize_t ltc2945_value_show(struct device *dev,
230                                   struct device_attribute *da, char *buf)
231 {
232         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
233         long long value;
234
235         value = ltc2945_reg_to_val(dev, attr->index);
236         if (value < 0)
237                 return value;
238         return snprintf(buf, PAGE_SIZE, "%lld\n", value);
239 }
240
241 static ssize_t ltc2945_value_store(struct device *dev,
242                                    struct device_attribute *da,
243                                    const char *buf, size_t count)
244 {
245         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
246         struct regmap *regmap = dev_get_drvdata(dev);
247         u8 reg = attr->index;
248         unsigned long val;
249         u8 regbuf[3];
250         int num_regs;
251         int regval;
252         int ret;
253
254         ret = kstrtoul(buf, 10, &val);
255         if (ret)
256                 return ret;
257
258         /* convert to register value, then clamp and write result */
259         regval = ltc2945_val_to_reg(dev, reg, val);
260         if (is_power_reg(reg)) {
261                 regval = clamp_val(regval, 0, 0xffffff);
262                 regbuf[0] = regval >> 16;
263                 regbuf[1] = (regval >> 8) & 0xff;
264                 regbuf[2] = regval;
265                 num_regs = 3;
266         } else {
267                 regval = clamp_val(regval, 0, 0xfff) << 4;
268                 regbuf[0] = regval >> 8;
269                 regbuf[1] = regval & 0xff;
270                 num_regs = 2;
271         }
272         ret = regmap_bulk_write(regmap, reg, regbuf, num_regs);
273         return ret < 0 ? ret : count;
274 }
275
276 static ssize_t ltc2945_history_store(struct device *dev,
277                                      struct device_attribute *da,
278                                      const char *buf, size_t count)
279 {
280         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
281         struct regmap *regmap = dev_get_drvdata(dev);
282         u8 reg = attr->index;
283         int num_regs = is_power_reg(reg) ? 3 : 2;
284         u8 buf_min[3] = { 0xff, 0xff, 0xff };
285         u8 buf_max[3] = { 0, 0, 0 };
286         unsigned long val;
287         int ret;
288
289         ret = kstrtoul(buf, 10, &val);
290         if (ret)
291                 return ret;
292         if (val != 1)
293                 return -EINVAL;
294
295         ret = regmap_update_bits(regmap, LTC2945_CONTROL, CONTROL_TEST_MODE,
296                                  CONTROL_TEST_MODE);
297
298         /* Reset minimum */
299         ret = regmap_bulk_write(regmap, reg, buf_min, num_regs);
300         if (ret)
301                 return ret;
302
303         switch (reg) {
304         case LTC2945_MIN_POWER_H:
305                 reg = LTC2945_MAX_POWER_H;
306                 break;
307         case LTC2945_MIN_SENSE_H:
308                 reg = LTC2945_MAX_SENSE_H;
309                 break;
310         case LTC2945_MIN_VIN_H:
311                 reg = LTC2945_MAX_VIN_H;
312                 break;
313         case LTC2945_MIN_ADIN_H:
314                 reg = LTC2945_MAX_ADIN_H;
315                 break;
316         default:
317                 WARN_ONCE(1, "Bad register: 0x%x\n", reg);
318                 return -EINVAL;
319         }
320         /* Reset maximum */
321         ret = regmap_bulk_write(regmap, reg, buf_max, num_regs);
322
323         /* Try resetting test mode even if there was an error */
324         regmap_update_bits(regmap, LTC2945_CONTROL, CONTROL_TEST_MODE, 0);
325
326         return ret ? : count;
327 }
328
329 static ssize_t ltc2945_bool_show(struct device *dev,
330                                  struct device_attribute *da, char *buf)
331 {
332         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
333         struct regmap *regmap = dev_get_drvdata(dev);
334         unsigned int fault;
335         int ret;
336
337         ret = regmap_read(regmap, LTC2945_FAULT, &fault);
338         if (ret < 0)
339                 return ret;
340
341         fault &= attr->index;
342         if (fault)              /* Clear reported faults in chip register */
343                 regmap_update_bits(regmap, LTC2945_FAULT, attr->index, 0);
344
345         return snprintf(buf, PAGE_SIZE, "%d\n", !!fault);
346 }
347
348 /* Input voltages */
349
350 static SENSOR_DEVICE_ATTR_RO(in1_input, ltc2945_value, LTC2945_VIN_H);
351 static SENSOR_DEVICE_ATTR_RW(in1_min, ltc2945_value, LTC2945_MIN_VIN_THRES_H);
352 static SENSOR_DEVICE_ATTR_RW(in1_max, ltc2945_value, LTC2945_MAX_VIN_THRES_H);
353 static SENSOR_DEVICE_ATTR_RO(in1_lowest, ltc2945_value, LTC2945_MIN_VIN_H);
354 static SENSOR_DEVICE_ATTR_RO(in1_highest, ltc2945_value, LTC2945_MAX_VIN_H);
355 static SENSOR_DEVICE_ATTR_WO(in1_reset_history, ltc2945_history,
356                              LTC2945_MIN_VIN_H);
357
358 static SENSOR_DEVICE_ATTR_RO(in2_input, ltc2945_value, LTC2945_ADIN_H);
359 static SENSOR_DEVICE_ATTR_RW(in2_min, ltc2945_value, LTC2945_MIN_ADIN_THRES_H);
360 static SENSOR_DEVICE_ATTR_RW(in2_max, ltc2945_value, LTC2945_MAX_ADIN_THRES_H);
361 static SENSOR_DEVICE_ATTR_RO(in2_lowest, ltc2945_value, LTC2945_MIN_ADIN_H);
362 static SENSOR_DEVICE_ATTR_RO(in2_highest, ltc2945_value, LTC2945_MAX_ADIN_H);
363 static SENSOR_DEVICE_ATTR_WO(in2_reset_history, ltc2945_history,
364                              LTC2945_MIN_ADIN_H);
365
366 /* Voltage alarms */
367
368 static SENSOR_DEVICE_ATTR_RO(in1_min_alarm, ltc2945_bool, FAULT_VIN_UV);
369 static SENSOR_DEVICE_ATTR_RO(in1_max_alarm, ltc2945_bool, FAULT_VIN_OV);
370 static SENSOR_DEVICE_ATTR_RO(in2_min_alarm, ltc2945_bool, FAULT_ADIN_UV);
371 static SENSOR_DEVICE_ATTR_RO(in2_max_alarm, ltc2945_bool, FAULT_ADIN_OV);
372
373 /* Currents (via sense resistor) */
374
375 static SENSOR_DEVICE_ATTR_RO(curr1_input, ltc2945_value, LTC2945_SENSE_H);
376 static SENSOR_DEVICE_ATTR_RW(curr1_min, ltc2945_value,
377                              LTC2945_MIN_SENSE_THRES_H);
378 static SENSOR_DEVICE_ATTR_RW(curr1_max, ltc2945_value,
379                              LTC2945_MAX_SENSE_THRES_H);
380 static SENSOR_DEVICE_ATTR_RO(curr1_lowest, ltc2945_value, LTC2945_MIN_SENSE_H);
381 static SENSOR_DEVICE_ATTR_RO(curr1_highest, ltc2945_value,
382                              LTC2945_MAX_SENSE_H);
383 static SENSOR_DEVICE_ATTR_WO(curr1_reset_history, ltc2945_history,
384                              LTC2945_MIN_SENSE_H);
385
386 /* Current alarms */
387
388 static SENSOR_DEVICE_ATTR_RO(curr1_min_alarm, ltc2945_bool, FAULT_SENSE_UV);
389 static SENSOR_DEVICE_ATTR_RO(curr1_max_alarm, ltc2945_bool, FAULT_SENSE_OV);
390
391 /* Power */
392
393 static SENSOR_DEVICE_ATTR_RO(power1_input, ltc2945_value, LTC2945_POWER_H);
394 static SENSOR_DEVICE_ATTR_RW(power1_min, ltc2945_value,
395                              LTC2945_MIN_POWER_THRES_H);
396 static SENSOR_DEVICE_ATTR_RW(power1_max, ltc2945_value,
397                              LTC2945_MAX_POWER_THRES_H);
398 static SENSOR_DEVICE_ATTR_RO(power1_input_lowest, ltc2945_value,
399                              LTC2945_MIN_POWER_H);
400 static SENSOR_DEVICE_ATTR_RO(power1_input_highest, ltc2945_value,
401                              LTC2945_MAX_POWER_H);
402 static SENSOR_DEVICE_ATTR_WO(power1_reset_history, ltc2945_history,
403                              LTC2945_MIN_POWER_H);
404
405 /* Power alarms */
406
407 static SENSOR_DEVICE_ATTR_RO(power1_min_alarm, ltc2945_bool, FAULT_POWER_UV);
408 static SENSOR_DEVICE_ATTR_RO(power1_max_alarm, ltc2945_bool, FAULT_POWER_OV);
409
410 static struct attribute *ltc2945_attrs[] = {
411         &sensor_dev_attr_in1_input.dev_attr.attr,
412         &sensor_dev_attr_in1_min.dev_attr.attr,
413         &sensor_dev_attr_in1_max.dev_attr.attr,
414         &sensor_dev_attr_in1_lowest.dev_attr.attr,
415         &sensor_dev_attr_in1_highest.dev_attr.attr,
416         &sensor_dev_attr_in1_reset_history.dev_attr.attr,
417         &sensor_dev_attr_in1_min_alarm.dev_attr.attr,
418         &sensor_dev_attr_in1_max_alarm.dev_attr.attr,
419
420         &sensor_dev_attr_in2_input.dev_attr.attr,
421         &sensor_dev_attr_in2_min.dev_attr.attr,
422         &sensor_dev_attr_in2_max.dev_attr.attr,
423         &sensor_dev_attr_in2_lowest.dev_attr.attr,
424         &sensor_dev_attr_in2_highest.dev_attr.attr,
425         &sensor_dev_attr_in2_reset_history.dev_attr.attr,
426         &sensor_dev_attr_in2_min_alarm.dev_attr.attr,
427         &sensor_dev_attr_in2_max_alarm.dev_attr.attr,
428
429         &sensor_dev_attr_curr1_input.dev_attr.attr,
430         &sensor_dev_attr_curr1_min.dev_attr.attr,
431         &sensor_dev_attr_curr1_max.dev_attr.attr,
432         &sensor_dev_attr_curr1_lowest.dev_attr.attr,
433         &sensor_dev_attr_curr1_highest.dev_attr.attr,
434         &sensor_dev_attr_curr1_reset_history.dev_attr.attr,
435         &sensor_dev_attr_curr1_min_alarm.dev_attr.attr,
436         &sensor_dev_attr_curr1_max_alarm.dev_attr.attr,
437
438         &sensor_dev_attr_power1_input.dev_attr.attr,
439         &sensor_dev_attr_power1_min.dev_attr.attr,
440         &sensor_dev_attr_power1_max.dev_attr.attr,
441         &sensor_dev_attr_power1_input_lowest.dev_attr.attr,
442         &sensor_dev_attr_power1_input_highest.dev_attr.attr,
443         &sensor_dev_attr_power1_reset_history.dev_attr.attr,
444         &sensor_dev_attr_power1_min_alarm.dev_attr.attr,
445         &sensor_dev_attr_power1_max_alarm.dev_attr.attr,
446
447         NULL,
448 };
449 ATTRIBUTE_GROUPS(ltc2945);
450
451 static const struct regmap_config ltc2945_regmap_config = {
452         .reg_bits = 8,
453         .val_bits = 8,
454         .max_register = LTC2945_MIN_ADIN_THRES_L,
455 };
456
457 static int ltc2945_probe(struct i2c_client *client,
458                          const struct i2c_device_id *id)
459 {
460         struct device *dev = &client->dev;
461         struct device *hwmon_dev;
462         struct regmap *regmap;
463
464         regmap = devm_regmap_init_i2c(client, &ltc2945_regmap_config);
465         if (IS_ERR(regmap)) {
466                 dev_err(dev, "failed to allocate register map\n");
467                 return PTR_ERR(regmap);
468         }
469
470         /* Clear faults */
471         regmap_write(regmap, LTC2945_FAULT, 0x00);
472
473         hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
474                                                            regmap,
475                                                            ltc2945_groups);
476         return PTR_ERR_OR_ZERO(hwmon_dev);
477 }
478
479 static const struct i2c_device_id ltc2945_id[] = {
480         {"ltc2945", 0},
481         { }
482 };
483
484 MODULE_DEVICE_TABLE(i2c, ltc2945_id);
485
486 static struct i2c_driver ltc2945_driver = {
487         .driver = {
488                    .name = "ltc2945",
489                    },
490         .probe = ltc2945_probe,
491         .id_table = ltc2945_id,
492 };
493
494 module_i2c_driver(ltc2945_driver);
495
496 MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
497 MODULE_DESCRIPTION("LTC2945 driver");
498 MODULE_LICENSE("GPL");