1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
|
// SPDX-License-Identifier: GPL-2.0
/*
* Lochnagar hardware monitoring features
*
* Copyright (c) 2016-2019 Cirrus Logic, Inc. and
* Cirrus Logic International Semiconductor Ltd.
*
* Author: Lucas Tanure <tanureal@opensource.cirrus.com>
*/
#include <linux/delay.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/i2c.h>
#include <linux/math64.h>
#include <linux/mfd/lochnagar.h>
#include <linux/mfd/lochnagar2_regs.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#define LN2_MAX_NSAMPLE 1023
#define LN2_SAMPLE_US 1670
#define LN2_CURR_UNITS 1000
#define LN2_VOLT_UNITS 1000
#define LN2_TEMP_UNITS 1000
#define LN2_PWR_UNITS 1000000
static const char * const lochnagar_chan_names[] = {
"DBVDD1",
"1V8 DSP",
"1V8 CDC",
"VDDCORE DSP",
"AVDD 1V8",
"SYSVDD",
"VDDCORE CDC",
"MICVDD",
};
struct lochnagar_hwmon {
struct regmap *regmap;
long power_nsamples[ARRAY_SIZE(lochnagar_chan_names)];
/* Lock to ensure only a single sensor is read at a time */
struct mutex sensor_lock;
};
enum lochnagar_measure_mode {
LN2_CURR = 0,
LN2_VOLT,
LN2_TEMP,
};
/**
* float_to_long - Convert ieee754 reading from hardware to an integer
*
* @data: Value read from the hardware
* @precision: Units to multiply up to eg. 1000 = milli, 1000000 = micro
*
* Return: Converted integer reading
*
* Depending on the measurement type the hardware returns an ieee754
* floating point value in either volts, amps or celsius. This function
* will convert that into an integer in a smaller unit such as micro-amps
* or milli-celsius. The hardware does not return NaN, so consideration of
* that is not required.
*/
static long float_to_long(u32 data, u32 precision)
{
u64 man = data & 0x007FFFFF;
int exp = ((data & 0x7F800000) >> 23) - 127 - 23;
bool negative = data & 0x80000000;
long result;
man = (man + (1 << 23)) * precision;
if (fls64(man) + exp > (int)sizeof(long) * 8 - 1)
result = LONG_MAX;
else if (exp < 0)
result = (man + (1ull << (-exp - 1))) >> -exp;
else
result = man << exp;
return negative ? -result : result;
}
static int do_measurement(struct regmap *regmap, int chan,
enum lochnagar_measure_mode mode, int nsamples)
{
unsigned int val;
int ret;
chan = 1 << (chan + LOCHNAGAR2_IMON_MEASURED_CHANNELS_SHIFT);
ret = regmap_write(regmap, LOCHNAGAR2_IMON_CTRL1,
LOCHNAGAR2_IMON_ENA_MASK | chan | mode);
if (ret < 0)
return ret;
ret = regmap_write(regmap, LOCHNAGAR2_IMON_CTRL2, nsamples);
if (ret < 0)
return ret;
ret = regmap_write(regmap, LOCHNAGAR2_IMON_CTRL3,
LOCHNAGAR2_IMON_CONFIGURE_MASK);
if (ret < 0)
return ret;
ret = regmap_read_poll_timeout(regmap, LOCHNAGAR2_IMON_CTRL3, val,
val & LOCHNAGAR2_IMON_DONE_MASK,
1000, 10000);
if (ret < 0)
return ret;
ret = regmap_write(regmap, LOCHNAGAR2_IMON_CTRL3,
LOCHNAGAR2_IMON_MEASURE_MASK);
if (ret < 0)
return ret;
/*
* Actual measurement time is ~1.67mS per sample, approximate this
* with a 1.5mS per sample msleep and then poll for success up to
* ~0.17mS * 1023 (LN2_MAX_NSAMPLES). Normally for smaller values
* of nsamples the poll will complete on the first loop due to
* other latency in the system.
*/
msleep((nsamples * 3) / 2);
ret = regmap_read_poll_timeout(regmap, LOCHNAGAR2_IMON_CTRL3, val,
val & LOCHNAGAR2_IMON_DONE_MASK,
5000, 200000);
if (ret < 0)
return ret;
return regmap_write(regmap, LOCHNAGAR2_IMON_CTRL3, 0);
}
static int request_data(struct regmap *regmap, int chan, u32 *data)
{
unsigned int val;
int ret;
ret = regmap_write(regmap, LOCHNAGAR2_IMON_CTRL4,
LOCHNAGAR2_IMON_DATA_REQ_MASK |
chan << LOCHNAGAR2_IMON_CH_SEL_SHIFT);
if (ret < 0)
return ret;
ret = regmap_read_poll_timeout(regmap, LOCHNAGAR2_IMON_CTRL4, val,
val & LOCHNAGAR2_IMON_DATA_RDY_MASK,
1000, 10000);
if (ret < 0)
return ret;
ret = regmap_read(regmap, LOCHNAGAR2_IMON_DATA1, &val);
if (ret < 0)
return ret;
*data = val << 16;
ret = regmap_read(regmap, LOCHNAGAR2_IMON_DATA2, &val);
if (ret < 0)
return ret;
*data |= val;
return regmap_write(regmap, LOCHNAGAR2_IMON_CTRL4, 0);
}
static int read_sensor(struct device *dev, int chan,
enum lochnagar_measure_mode mode, int nsamples,
unsigned int precision, long *val)
{
struct lochnagar_hwmon *priv = dev_get_drvdata(dev);
struct regmap *regmap = priv->regmap;
u32 data;
int ret;
mutex_lock(&priv->sensor_lock);
ret = do_measurement(regmap, chan, mode, nsamples);
if (ret < 0) {
dev_err(dev, "Failed to perform measurement: %d\n", ret);
goto error;
}
ret = request_data(regmap, chan, &data);
if (ret < 0) {
dev_err(dev, "Failed to read measurement: %d\n", ret);
goto error;
}
*val = float_to_long(data, precision);
error:
mutex_unlock(&priv->sensor_lock);
return ret;
}
static int read_power(struct device *dev, int chan, long *val)
{
struct lochnagar_hwmon *priv = dev_get_drvdata(dev);
int nsamples = priv->power_nsamples[chan];
u64 power;
int ret;
if (!strcmp("SYSVDD", lochnagar_chan_names[chan])) {
power = 5 * LN2_PWR_UNITS;
} else {
ret = read_sensor(dev, chan, LN2_VOLT, 1, LN2_PWR_UNITS, val);
if (ret < 0)
return ret;
power = abs(*val);
}
ret = read_sensor(dev, chan, LN2_CURR, nsamples, LN2_PWR_UNITS, val);
if (ret < 0)
return ret;
power *= abs(*val);
power = DIV_ROUND_CLOSEST_ULL(power, LN2_PWR_UNITS);
if (power > LONG_MAX)
*val = LONG_MAX;
else
*val = power;
return 0;
}
static umode_t lochnagar_is_visible(const void *drvdata,
enum hwmon_sensor_types type,
u32 attr, int chan)
{
switch (type) {
case hwmon_in:
if (!strcmp("SYSVDD", lochnagar_chan_names[chan]))
return 0;
break;
case hwmon_power:
if (attr == hwmon_power_average_interval)
return 0644;
break;
default:
break;
}
return 0444;
}
static int lochnagar_read(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int chan, long *val)
{
struct lochnagar_hwmon *priv = dev_get_drvdata(dev);
int interval;
switch (type) {
case hwmon_in:
return read_sensor(dev, chan, LN2_VOLT, 1, LN2_VOLT_UNITS, val);
case hwmon_curr:
return read_sensor(dev, chan, LN2_CURR, 1, LN2_CURR_UNITS, val);
case hwmon_temp:
return read_sensor(dev, chan, LN2_TEMP
|