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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Lochnagar hardware monitoring features
4 *
5 * Copyright (c) 2016-2019 Cirrus Logic, Inc. and
6 * Cirrus Logic International Semiconductor Ltd.
7 *
8 * Author: Lucas Tanure <tanureal@opensource.cirrus.com>
9 */
10
11#include <linux/delay.h>
12#include <linux/hwmon.h>
13#include <linux/hwmon-sysfs.h>
14#include <linux/i2c.h>
15#include <linux/math64.h>
16#include <linux/mfd/lochnagar.h>
17#include <linux/mfd/lochnagar2_regs.h>
18#include <linux/module.h>
19#include <linux/of.h>
20#include <linux/of_device.h>
21#include <linux/platform_device.h>
22#include <linux/regmap.h>
23
24#define LN2_MAX_NSAMPLE 1023
25#define LN2_SAMPLE_US 1670
26
27#define LN2_CURR_UNITS 1000
28#define LN2_VOLT_UNITS 1000
29#define LN2_TEMP_UNITS 1000
30#define LN2_PWR_UNITS 1000000
31
32static const char * const lochnagar_chan_names[] = {
33 "DBVDD1",
34 "1V8 DSP",
35 "1V8 CDC",
36 "VDDCORE DSP",
37 "AVDD 1V8",
38 "SYSVDD",
39 "VDDCORE CDC",
40 "MICVDD",
41};
42
43struct lochnagar_hwmon {
44 struct regmap *regmap;
45
46 long power_nsamples[ARRAY_SIZE(lochnagar_chan_names)];
47
48 /* Lock to ensure only a single sensor is read at a time */
49 struct mutex sensor_lock;
50};
51
52enum lochnagar_measure_mode {
53 LN2_CURR = 0,
54 LN2_VOLT,
55 LN2_TEMP,
56};
57
58/**
59 * float_to_long - Convert ieee754 reading from hardware to an integer
60 *
61 * @data: Value read from the hardware
62 * @precision: Units to multiply up to eg. 1000 = milli, 1000000 = micro
63 *
64 * Return: Converted integer reading
65 *
66 * Depending on the measurement type the hardware returns an ieee754
67 * floating point value in either volts, amps or celsius. This function
68 * will convert that into an integer in a smaller unit such as micro-amps
69 * or milli-celsius. The hardware does not return NaN, so consideration of
70 * that is not required.
71 */
72static long float_to_long(u32 data, u32 precision)
73{
74 u64 man = data & 0x007FFFFF;
75 int exp = ((data & 0x7F800000) >> 23) - 127 - 23;
76 bool negative = data & 0x80000000;
77 long result;
78
79 man = (man + (1 << 23)) * precision;
80
81 if (fls64(man) + exp > (int)sizeof(long) * 8 - 1)
82 result = LONG_MAX;
83 else if (exp < 0)
84 result = (man + (1ull << (-exp - 1))) >> -exp;
85 else
86 result = man << exp;
87
88 return negative ? -result : result;
89}
90
91static int do_measurement(struct regmap *regmap, int chan,
92 enum lochnagar_measure_mode mode, int nsamples)
93{
94 unsigned int val;
95 int ret;
96
97 chan = 1 << (chan + LOCHNAGAR2_IMON_MEASURED_CHANNELS_SHIFT);
98
99 ret = regmap_write(regmap, LOCHNAGAR2_IMON_CTRL1,
100 LOCHNAGAR2_IMON_ENA_MASK | chan | mode);
101 if (ret < 0)
102 return ret;
103
104 ret = regmap_write(regmap, LOCHNAGAR2_IMON_CTRL2, nsamples);
105 if (ret < 0)
106 return ret;
107
108 ret = regmap_write(regmap, LOCHNAGAR2_IMON_CTRL3,
109 LOCHNAGAR2_IMON_CONFIGURE_MASK);
110 if (ret < 0)
111 return ret;
112
113 ret = regmap_read_poll_timeout(regmap, LOCHNAGAR2_IMON_CTRL3, val,
114 val & LOCHNAGAR2_IMON_DONE_MASK,
115 1000, 10000);
116 if (ret < 0)
117 return ret;
118
119 ret = regmap_write(regmap, LOCHNAGAR2_IMON_CTRL3,
120 LOCHNAGAR2_IMON_MEASURE_MASK);
121 if (ret < 0)
122 return ret;
123
124 /*
125 * Actual measurement time is ~1.67mS per sample, approximate this
126 * with a 1.5mS per sample msleep and then poll for success up to
127 * ~0.17mS * 1023 (LN2_MAX_NSAMPLES). Normally for smaller values
128 * of nsamples the poll will complete on the first loop due to
129 * other latency in the system.
130 */
131 msleep((nsamples * 3) / 2);
132
133 ret = regmap_read_poll_timeout(regmap, LOCHNAGAR2_IMON_CTRL3, val,
134 val & LOCHNAGAR2_IMON_DONE_MASK,
135 5000, 200000);
136 if (ret < 0)
137 return ret;
138
139 return regmap_write(regmap, LOCHNAGAR2_IMON_CTRL3, 0);
140}
141
142static int request_data(struct regmap *regmap, int chan, u32 *data)
143{
144 unsigned int val;
145 int ret;
146
147 ret = regmap_write(regmap, LOCHNAGAR2_IMON_CTRL4,
148 LOCHNAGAR2_IMON_DATA_REQ_MASK |
149 chan << LOCHNAGAR2_IMON_CH_SEL_SHIFT);
150 if (ret < 0)
151 return ret;
152
153 ret = regmap_read_poll_timeout(regmap, LOCHNAGAR2_IMON_CTRL4, val,
154 val & LOCHNAGAR2_IMON_DATA_RDY_MASK,
155 1000, 10000);
156 if (ret < 0)
157 return ret;
158
159 ret = regmap_read(regmap, LOCHNAGAR2_IMON_DATA1, &val);
160 if (ret < 0)
161 return ret;
162
163 *data = val << 16;
164
165 ret = regmap_read(regmap, LOCHNAGAR2_IMON_DATA2, &val);
166 if (ret < 0)
167 return ret;
168
169 *data |= val;
170
171 return regmap_write(regmap, LOCHNAGAR2_IMON_CTRL4, 0);
172}
173
174static int read_sensor(struct device *dev, int chan,
175 enum lochnagar_measure_mode mode, int nsamples,
176 unsigned int precision, long *val)
177{
178 struct lochnagar_hwmon *priv = dev_get_drvdata(dev);
179 struct regmap *regmap = priv->regmap;
180 u32 data;
181 int ret;
182
183 mutex_lock(&priv->sensor_lock);
184
185 ret = do_measurement(regmap, chan, mode, nsamples);
186 if (ret < 0) {
187 dev_err(dev, "Failed to perform measurement: %d\n", ret);
188 goto error;
189 }
190
191 ret = request_data(regmap, chan, &data);
192 if (ret < 0) {
193 dev_err(dev, "Failed to read measurement: %d\n", ret);
194 goto error;
195 }
196
197 *val = float_to_long(data, precision);
198
199error:
200 mutex_unlock(&priv->sensor_lock);
201
202 return ret;
203}
204
205static int read_power(struct device *dev, int chan, long *val)
206{
207 struct lochnagar_hwmon *priv = dev_get_drvdata(dev);
208 int nsamples = priv->power_nsamples[chan];
209 u64 power;
210 int ret;
211
212 if (!strcmp("SYSVDD", lochnagar_chan_names[chan])) {
213 power = 5 * LN2_PWR_UNITS;
214 } else {
215 ret = read_sensor(dev, chan, LN2_VOLT, 1, LN2_PWR_UNITS, val);
216 if (ret < 0)
217 return ret;
218
219 power = abs(*val);
220 }
221
222 ret = read_sensor(dev, chan, LN2_CURR, nsamples, LN2_PWR_UNITS, val);
223 if (ret < 0)
224 return ret;
225
226 power *= abs(*val);
227 power = DIV_ROUND_CLOSEST_ULL(power, LN2_PWR_UNITS);
228
229 if (power > LONG_MAX)
230 *val = LONG_MAX;
231 else
232 *val = power;
233
234 return 0;
235}
236
237static umode_t lochnagar_is_visible(const void *drvdata,
238 enum hwmon_sensor_types type,
239 u32 attr, int chan)
240{
241 switch (type) {
242 case hwmon_in:
243 if (!strcmp("SYSVDD", lochnagar_chan_names[chan]))
244 return 0;
245 break;
246 case hwmon_power:
247 if (attr == hwmon_power_average_interval)
248 return 0644;
249 break;
250 default:
251 break;
252 }
253
254 return 0444;
255}
256
257static int lochnagar_read(struct device *dev, enum hwmon_sensor_types type,
258 u32 attr, int chan, long *val)
259{
260 struct lochnagar_hwmon *priv = dev_get_drvdata(dev);
261 int interval;
262
263 switch (type) {
264 case hwmon_in:
265 return read_sensor(dev, chan, LN2_VOLT, 1, LN2_VOLT_UNITS, val);
266 case hwmon_curr:
267 return read_sensor(dev, chan, LN2_CURR, 1, LN2_CURR_UNITS, val);
268 case hwmon_temp:
269 return read_sensor(dev, chan, LN2_TEMP, 1, LN2_TEMP_UNITS, val);
270 case hwmon_power:
271 switch (attr) {
272 case hwmon_power_average:
273 return read_power(dev, chan, val);
274 case hwmon_power_average_interval:
275 interval = priv->power_nsamples[chan] * LN2_SAMPLE_US;
276 *val = DIV_ROUND_CLOSEST(interval, 1000);
277 return 0;
278 default:
279 return -EOPNOTSUPP;
280 }
281 default:
282 return -EOPNOTSUPP;
283 }
284}
285
286static int lochnagar_read_string(struct device *dev,
287 enum hwmon_sensor_types type, u32 attr,
288 int chan, const char **str)
289{
290 switch (type) {
291 case hwmon_in:
292 case hwmon_curr:
293 case hwmon_power:
294 *str = lochnagar_chan_names[chan];
295 return 0;
296 default:
297 return -EOPNOTSUPP;
298 }
299}
300
301static int lochnagar_write(struct device *dev, enum hwmon_sensor_types type,
302 u32 attr, int chan, long val)
303{
304 struct lochnagar_hwmon *priv = dev_get_drvdata(dev);
305
306 if (type != hwmon_power || attr != hwmon_power_average_interval)
307 return -EOPNOTSUPP;
308
309 val = clamp_t(long, val, 1, (LN2_MAX_NSAMPLE * LN2_SAMPLE_US) / 1000);
310 val = DIV_ROUND_CLOSEST(val * 1000, LN2_SAMPLE_US);
311
312 priv->power_nsamples[chan] = val;
313
314 return 0;
315}
316
317static const struct hwmon_ops lochnagar_ops = {
318 .is_visible = lochnagar_is_visible,
319 .read = lochnagar_read,
320 .read_string = lochnagar_read_string,
321 .write = lochnagar_write,
322};
323
324static const struct hwmon_channel_info *lochnagar_info[] = {
325 HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
326 HWMON_CHANNEL_INFO(in, HWMON_I_INPUT | HWMON_I_LABEL,
327 HWMON_I_INPUT | HWMON_I_LABEL,
328 HWMON_I_INPUT | HWMON_I_LABEL,
329 HWMON_I_INPUT | HWMON_I_LABEL,
330 HWMON_I_INPUT | HWMON_I_LABEL,
331 HWMON_I_INPUT | HWMON_I_LABEL,
332 HWMON_I_INPUT | HWMON_I_LABEL,
333 HWMON_I_INPUT | HWMON_I_LABEL),
334 HWMON_CHANNEL_INFO(curr, HWMON_C_INPUT | HWMON_C_LABEL,
335 HWMON_C_INPUT | HWMON_C_LABEL,
336 HWMON_C_INPUT | HWMON_C_LABEL,
337 HWMON_C_INPUT | HWMON_C_LABEL,
338 HWMON_C_INPUT | HWMON_C_LABEL,
339 HWMON_C_INPUT | HWMON_C_LABEL,
340 HWMON_C_INPUT | HWMON_C_LABEL,
341 HWMON_C_INPUT | HWMON_C_LABEL),
342 HWMON_CHANNEL_INFO(power, HWMON_P_AVERAGE | HWMON_P_AVERAGE_INTERVAL |
343 HWMON_P_LABEL,
344 HWMON_P_AVERAGE | HWMON_P_AVERAGE_INTERVAL |
345 HWMON_P_LABEL,
346 HWMON_P_AVERAGE | HWMON_P_AVERAGE_INTERVAL |
347 HWMON_P_LABEL,
348 HWMON_P_AVERAGE | HWMON_P_AVERAGE_INTERVAL |
349 HWMON_P_LABEL,
350 HWMON_P_AVERAGE | HWMON_P_AVERAGE_INTERVAL |
351 HWMON_P_LABEL,
352 HWMON_P_AVERAGE | HWMON_P_AVERAGE_INTERVAL |
353 HWMON_P_LABEL,
354 HWMON_P_AVERAGE | HWMON_P_AVERAGE_INTERVAL |
355 HWMON_P_LABEL,
356 HWMON_P_AVERAGE | HWMON_P_AVERAGE_INTERVAL |
357 HWMON_P_LABEL),
358 NULL
359};
360
361static const struct hwmon_chip_info lochnagar_chip_info = {
362 .ops = &lochnagar_ops,
363 .info = lochnagar_info,
364};
365
366static const struct of_device_id lochnagar_of_match[] = {
367 { .compatible = "cirrus,lochnagar2-hwmon" },
368 {}
369};
370MODULE_DEVICE_TABLE(of, lochnagar_of_match);
371
372static int lochnagar_hwmon_probe(struct platform_device *pdev)
373{
374 struct device *dev = &pdev->dev;
375 struct device *hwmon_dev;
376 struct lochnagar_hwmon *priv;
377 int i;
378
379 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
380 if (!priv)
381 return -ENOMEM;
382
383 mutex_init(&priv->sensor_lock);
384
385 priv->regmap = dev_get_regmap(dev->parent, NULL);
386 if (!priv->regmap) {
387 dev_err(dev, "No register map found\n");
388 return -EINVAL;
389 }
390
391 for (i = 0; i < ARRAY_SIZE(priv->power_nsamples); i++)
392 priv->power_nsamples[i] = 96;
393
394 hwmon_dev = devm_hwmon_device_register_with_info(dev, "Lochnagar", priv,
395 &lochnagar_chip_info,
396 NULL);
397
398 return PTR_ERR_OR_ZERO(hwmon_dev);
399}
400
401static struct platform_driver lochnagar_hwmon_driver = {
402 .driver = {
403 .name = "lochnagar-hwmon",
404 .of_match_table = lochnagar_of_match,
405 },
406 .probe = lochnagar_hwmon_probe,
407};
408module_platform_driver(lochnagar_hwmon_driver);
409
410MODULE_AUTHOR("Lucas Tanure <tanureal@opensource.cirrus.com>");
411MODULE_DESCRIPTION("Lochnagar hardware monitoring features");
412MODULE_LICENSE("GPL");