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