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