Loading...
Note: File does not exist in v3.1.
1/*
2 * Copyright 2013 Freescale Semiconductor, Inc.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 */
9
10#include <linux/clk.h>
11#include <linux/cpu_cooling.h>
12#include <linux/cpufreq.h>
13#include <linux/delay.h>
14#include <linux/device.h>
15#include <linux/init.h>
16#include <linux/interrupt.h>
17#include <linux/io.h>
18#include <linux/kernel.h>
19#include <linux/mfd/syscon.h>
20#include <linux/module.h>
21#include <linux/of.h>
22#include <linux/platform_device.h>
23#include <linux/regmap.h>
24#include <linux/slab.h>
25#include <linux/thermal.h>
26#include <linux/types.h>
27
28#define REG_SET 0x4
29#define REG_CLR 0x8
30#define REG_TOG 0xc
31
32#define MISC0 0x0150
33#define MISC0_REFTOP_SELBIASOFF (1 << 3)
34
35#define TEMPSENSE0 0x0180
36#define TEMPSENSE0_ALARM_VALUE_SHIFT 20
37#define TEMPSENSE0_ALARM_VALUE_MASK (0xfff << TEMPSENSE0_ALARM_VALUE_SHIFT)
38#define TEMPSENSE0_TEMP_CNT_SHIFT 8
39#define TEMPSENSE0_TEMP_CNT_MASK (0xfff << TEMPSENSE0_TEMP_CNT_SHIFT)
40#define TEMPSENSE0_FINISHED (1 << 2)
41#define TEMPSENSE0_MEASURE_TEMP (1 << 1)
42#define TEMPSENSE0_POWER_DOWN (1 << 0)
43
44#define TEMPSENSE1 0x0190
45#define TEMPSENSE1_MEASURE_FREQ 0xffff
46
47#define OCOTP_ANA1 0x04e0
48
49/* The driver supports 1 passive trip point and 1 critical trip point */
50enum imx_thermal_trip {
51 IMX_TRIP_PASSIVE,
52 IMX_TRIP_CRITICAL,
53 IMX_TRIP_NUM,
54};
55
56/*
57 * It defines the temperature in millicelsius for passive trip point
58 * that will trigger cooling action when crossed.
59 */
60#define IMX_TEMP_PASSIVE 85000
61
62#define IMX_POLLING_DELAY 2000 /* millisecond */
63#define IMX_PASSIVE_DELAY 1000
64
65#define FACTOR0 10000000
66#define FACTOR1 15976
67#define FACTOR2 4297157
68
69struct imx_thermal_data {
70 struct thermal_zone_device *tz;
71 struct thermal_cooling_device *cdev;
72 enum thermal_device_mode mode;
73 struct regmap *tempmon;
74 u32 c1, c2; /* See formula in imx_get_sensor_data() */
75 unsigned long temp_passive;
76 unsigned long temp_critical;
77 unsigned long alarm_temp;
78 unsigned long last_temp;
79 bool irq_enabled;
80 int irq;
81 struct clk *thermal_clk;
82};
83
84static void imx_set_alarm_temp(struct imx_thermal_data *data,
85 signed long alarm_temp)
86{
87 struct regmap *map = data->tempmon;
88 int alarm_value;
89
90 data->alarm_temp = alarm_temp;
91 alarm_value = (data->c2 - alarm_temp) / data->c1;
92 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_ALARM_VALUE_MASK);
93 regmap_write(map, TEMPSENSE0 + REG_SET, alarm_value <<
94 TEMPSENSE0_ALARM_VALUE_SHIFT);
95}
96
97static int imx_get_temp(struct thermal_zone_device *tz, unsigned long *temp)
98{
99 struct imx_thermal_data *data = tz->devdata;
100 struct regmap *map = data->tempmon;
101 unsigned int n_meas;
102 bool wait;
103 u32 val;
104
105 if (data->mode == THERMAL_DEVICE_ENABLED) {
106 /* Check if a measurement is currently in progress */
107 regmap_read(map, TEMPSENSE0, &val);
108 wait = !(val & TEMPSENSE0_FINISHED);
109 } else {
110 /*
111 * Every time we measure the temperature, we will power on the
112 * temperature sensor, enable measurements, take a reading,
113 * disable measurements, power off the temperature sensor.
114 */
115 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
116 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
117
118 wait = true;
119 }
120
121 /*
122 * According to the temp sensor designers, it may require up to ~17us
123 * to complete a measurement.
124 */
125 if (wait)
126 usleep_range(20, 50);
127
128 regmap_read(map, TEMPSENSE0, &val);
129
130 if (data->mode != THERMAL_DEVICE_ENABLED) {
131 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
132 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
133 }
134
135 if ((val & TEMPSENSE0_FINISHED) == 0) {
136 dev_dbg(&tz->device, "temp measurement never finished\n");
137 return -EAGAIN;
138 }
139
140 n_meas = (val & TEMPSENSE0_TEMP_CNT_MASK) >> TEMPSENSE0_TEMP_CNT_SHIFT;
141
142 /* See imx_get_sensor_data() for formula derivation */
143 *temp = data->c2 - n_meas * data->c1;
144
145 /* Update alarm value to next higher trip point */
146 if (data->alarm_temp == data->temp_passive && *temp >= data->temp_passive)
147 imx_set_alarm_temp(data, data->temp_critical);
148 if (data->alarm_temp == data->temp_critical && *temp < data->temp_passive) {
149 imx_set_alarm_temp(data, data->temp_passive);
150 dev_dbg(&tz->device, "thermal alarm off: T < %lu\n",
151 data->alarm_temp / 1000);
152 }
153
154 if (*temp != data->last_temp) {
155 dev_dbg(&tz->device, "millicelsius: %ld\n", *temp);
156 data->last_temp = *temp;
157 }
158
159 /* Reenable alarm IRQ if temperature below alarm temperature */
160 if (!data->irq_enabled && *temp < data->alarm_temp) {
161 data->irq_enabled = true;
162 enable_irq(data->irq);
163 }
164
165 return 0;
166}
167
168static int imx_get_mode(struct thermal_zone_device *tz,
169 enum thermal_device_mode *mode)
170{
171 struct imx_thermal_data *data = tz->devdata;
172
173 *mode = data->mode;
174
175 return 0;
176}
177
178static int imx_set_mode(struct thermal_zone_device *tz,
179 enum thermal_device_mode mode)
180{
181 struct imx_thermal_data *data = tz->devdata;
182 struct regmap *map = data->tempmon;
183
184 if (mode == THERMAL_DEVICE_ENABLED) {
185 tz->polling_delay = IMX_POLLING_DELAY;
186 tz->passive_delay = IMX_PASSIVE_DELAY;
187
188 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
189 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
190
191 if (!data->irq_enabled) {
192 data->irq_enabled = true;
193 enable_irq(data->irq);
194 }
195 } else {
196 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
197 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
198
199 tz->polling_delay = 0;
200 tz->passive_delay = 0;
201
202 if (data->irq_enabled) {
203 disable_irq(data->irq);
204 data->irq_enabled = false;
205 }
206 }
207
208 data->mode = mode;
209 thermal_zone_device_update(tz);
210
211 return 0;
212}
213
214static int imx_get_trip_type(struct thermal_zone_device *tz, int trip,
215 enum thermal_trip_type *type)
216{
217 *type = (trip == IMX_TRIP_PASSIVE) ? THERMAL_TRIP_PASSIVE :
218 THERMAL_TRIP_CRITICAL;
219 return 0;
220}
221
222static int imx_get_crit_temp(struct thermal_zone_device *tz,
223 unsigned long *temp)
224{
225 struct imx_thermal_data *data = tz->devdata;
226
227 *temp = data->temp_critical;
228 return 0;
229}
230
231static int imx_get_trip_temp(struct thermal_zone_device *tz, int trip,
232 unsigned long *temp)
233{
234 struct imx_thermal_data *data = tz->devdata;
235
236 *temp = (trip == IMX_TRIP_PASSIVE) ? data->temp_passive :
237 data->temp_critical;
238 return 0;
239}
240
241static int imx_set_trip_temp(struct thermal_zone_device *tz, int trip,
242 unsigned long temp)
243{
244 struct imx_thermal_data *data = tz->devdata;
245
246 if (trip == IMX_TRIP_CRITICAL)
247 return -EPERM;
248
249 if (temp > IMX_TEMP_PASSIVE)
250 return -EINVAL;
251
252 data->temp_passive = temp;
253
254 imx_set_alarm_temp(data, temp);
255
256 return 0;
257}
258
259static int imx_bind(struct thermal_zone_device *tz,
260 struct thermal_cooling_device *cdev)
261{
262 int ret;
263
264 ret = thermal_zone_bind_cooling_device(tz, IMX_TRIP_PASSIVE, cdev,
265 THERMAL_NO_LIMIT,
266 THERMAL_NO_LIMIT);
267 if (ret) {
268 dev_err(&tz->device,
269 "binding zone %s with cdev %s failed:%d\n",
270 tz->type, cdev->type, ret);
271 return ret;
272 }
273
274 return 0;
275}
276
277static int imx_unbind(struct thermal_zone_device *tz,
278 struct thermal_cooling_device *cdev)
279{
280 int ret;
281
282 ret = thermal_zone_unbind_cooling_device(tz, IMX_TRIP_PASSIVE, cdev);
283 if (ret) {
284 dev_err(&tz->device,
285 "unbinding zone %s with cdev %s failed:%d\n",
286 tz->type, cdev->type, ret);
287 return ret;
288 }
289
290 return 0;
291}
292
293static struct thermal_zone_device_ops imx_tz_ops = {
294 .bind = imx_bind,
295 .unbind = imx_unbind,
296 .get_temp = imx_get_temp,
297 .get_mode = imx_get_mode,
298 .set_mode = imx_set_mode,
299 .get_trip_type = imx_get_trip_type,
300 .get_trip_temp = imx_get_trip_temp,
301 .get_crit_temp = imx_get_crit_temp,
302 .set_trip_temp = imx_set_trip_temp,
303};
304
305static int imx_get_sensor_data(struct platform_device *pdev)
306{
307 struct imx_thermal_data *data = platform_get_drvdata(pdev);
308 struct regmap *map;
309 int t1, t2, n1, n2;
310 int ret;
311 u32 val;
312 u64 temp64;
313
314 map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
315 "fsl,tempmon-data");
316 if (IS_ERR(map)) {
317 ret = PTR_ERR(map);
318 dev_err(&pdev->dev, "failed to get sensor regmap: %d\n", ret);
319 return ret;
320 }
321
322 ret = regmap_read(map, OCOTP_ANA1, &val);
323 if (ret) {
324 dev_err(&pdev->dev, "failed to read sensor data: %d\n", ret);
325 return ret;
326 }
327
328 if (val == 0 || val == ~0) {
329 dev_err(&pdev->dev, "invalid sensor calibration data\n");
330 return -EINVAL;
331 }
332
333 /*
334 * Sensor data layout:
335 * [31:20] - sensor value @ 25C
336 * [19:8] - sensor value of hot
337 * [7:0] - hot temperature value
338 * Use universal formula now and only need sensor value @ 25C
339 * slope = 0.4297157 - (0.0015976 * 25C fuse)
340 */
341 n1 = val >> 20;
342 n2 = (val & 0xfff00) >> 8;
343 t2 = val & 0xff;
344 t1 = 25; /* t1 always 25C */
345
346 /*
347 * Derived from linear interpolation:
348 * slope = 0.4297157 - (0.0015976 * 25C fuse)
349 * slope = (FACTOR2 - FACTOR1 * n1) / FACTOR0
350 * (Nmeas - n1) / (Tmeas - t1) = slope
351 * We want to reduce this down to the minimum computation necessary
352 * for each temperature read. Also, we want Tmeas in millicelsius
353 * and we don't want to lose precision from integer division. So...
354 * Tmeas = (Nmeas - n1) / slope + t1
355 * milli_Tmeas = 1000 * (Nmeas - n1) / slope + 1000 * t1
356 * milli_Tmeas = -1000 * (n1 - Nmeas) / slope + 1000 * t1
357 * Let constant c1 = (-1000 / slope)
358 * milli_Tmeas = (n1 - Nmeas) * c1 + 1000 * t1
359 * Let constant c2 = n1 *c1 + 1000 * t1
360 * milli_Tmeas = c2 - Nmeas * c1
361 */
362 temp64 = FACTOR0;
363 temp64 *= 1000;
364 do_div(temp64, FACTOR1 * n1 - FACTOR2);
365 data->c1 = temp64;
366 data->c2 = n1 * data->c1 + 1000 * t1;
367
368 /*
369 * Set the default passive cooling trip point to 20 °C below the
370 * maximum die temperature. Can be changed from userspace.
371 */
372 data->temp_passive = 1000 * (t2 - 20);
373
374 /*
375 * The maximum die temperature is t2, let's give 5 °C cushion
376 * for noise and possible temperature rise between measurements.
377 */
378 data->temp_critical = 1000 * (t2 - 5);
379
380 return 0;
381}
382
383static irqreturn_t imx_thermal_alarm_irq(int irq, void *dev)
384{
385 struct imx_thermal_data *data = dev;
386
387 disable_irq_nosync(irq);
388 data->irq_enabled = false;
389
390 return IRQ_WAKE_THREAD;
391}
392
393static irqreturn_t imx_thermal_alarm_irq_thread(int irq, void *dev)
394{
395 struct imx_thermal_data *data = dev;
396
397 dev_dbg(&data->tz->device, "THERMAL ALARM: T > %lu\n",
398 data->alarm_temp / 1000);
399
400 thermal_zone_device_update(data->tz);
401
402 return IRQ_HANDLED;
403}
404
405static int imx_thermal_probe(struct platform_device *pdev)
406{
407 struct imx_thermal_data *data;
408 struct cpumask clip_cpus;
409 struct regmap *map;
410 int measure_freq;
411 int ret;
412
413 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
414 if (!data)
415 return -ENOMEM;
416
417 map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "fsl,tempmon");
418 if (IS_ERR(map)) {
419 ret = PTR_ERR(map);
420 dev_err(&pdev->dev, "failed to get tempmon regmap: %d\n", ret);
421 return ret;
422 }
423 data->tempmon = map;
424
425 data->irq = platform_get_irq(pdev, 0);
426 if (data->irq < 0)
427 return data->irq;
428
429 ret = devm_request_threaded_irq(&pdev->dev, data->irq,
430 imx_thermal_alarm_irq, imx_thermal_alarm_irq_thread,
431 0, "imx_thermal", data);
432 if (ret < 0) {
433 dev_err(&pdev->dev, "failed to request alarm irq: %d\n", ret);
434 return ret;
435 }
436
437 platform_set_drvdata(pdev, data);
438
439 ret = imx_get_sensor_data(pdev);
440 if (ret) {
441 dev_err(&pdev->dev, "failed to get sensor data\n");
442 return ret;
443 }
444
445 /* Make sure sensor is in known good state for measurements */
446 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
447 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
448 regmap_write(map, TEMPSENSE1 + REG_CLR, TEMPSENSE1_MEASURE_FREQ);
449 regmap_write(map, MISC0 + REG_SET, MISC0_REFTOP_SELBIASOFF);
450 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
451
452 cpumask_set_cpu(0, &clip_cpus);
453 data->cdev = cpufreq_cooling_register(&clip_cpus);
454 if (IS_ERR(data->cdev)) {
455 ret = PTR_ERR(data->cdev);
456 dev_err(&pdev->dev,
457 "failed to register cpufreq cooling device: %d\n", ret);
458 return ret;
459 }
460
461 data->tz = thermal_zone_device_register("imx_thermal_zone",
462 IMX_TRIP_NUM,
463 BIT(IMX_TRIP_PASSIVE), data,
464 &imx_tz_ops, NULL,
465 IMX_PASSIVE_DELAY,
466 IMX_POLLING_DELAY);
467 if (IS_ERR(data->tz)) {
468 ret = PTR_ERR(data->tz);
469 dev_err(&pdev->dev,
470 "failed to register thermal zone device %d\n", ret);
471 cpufreq_cooling_unregister(data->cdev);
472 return ret;
473 }
474
475 data->thermal_clk = devm_clk_get(&pdev->dev, NULL);
476 if (IS_ERR(data->thermal_clk)) {
477 dev_warn(&pdev->dev, "failed to get thermal clk!\n");
478 } else {
479 /*
480 * Thermal sensor needs clk on to get correct value, normally
481 * we should enable its clk before taking measurement and disable
482 * clk after measurement is done, but if alarm function is enabled,
483 * hardware will auto measure the temperature periodically, so we
484 * need to keep the clk always on for alarm function.
485 */
486 ret = clk_prepare_enable(data->thermal_clk);
487 if (ret)
488 dev_warn(&pdev->dev, "failed to enable thermal clk: %d\n", ret);
489 }
490
491 /* Enable measurements at ~ 10 Hz */
492 regmap_write(map, TEMPSENSE1 + REG_CLR, TEMPSENSE1_MEASURE_FREQ);
493 measure_freq = DIV_ROUND_UP(32768, 10); /* 10 Hz */
494 regmap_write(map, TEMPSENSE1 + REG_SET, measure_freq);
495 imx_set_alarm_temp(data, data->temp_passive);
496 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
497 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
498
499 data->irq_enabled = true;
500 data->mode = THERMAL_DEVICE_ENABLED;
501
502 return 0;
503}
504
505static int imx_thermal_remove(struct platform_device *pdev)
506{
507 struct imx_thermal_data *data = platform_get_drvdata(pdev);
508 struct regmap *map = data->tempmon;
509
510 /* Disable measurements */
511 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
512 if (!IS_ERR(data->thermal_clk))
513 clk_disable_unprepare(data->thermal_clk);
514
515 thermal_zone_device_unregister(data->tz);
516 cpufreq_cooling_unregister(data->cdev);
517
518 return 0;
519}
520
521#ifdef CONFIG_PM_SLEEP
522static int imx_thermal_suspend(struct device *dev)
523{
524 struct imx_thermal_data *data = dev_get_drvdata(dev);
525 struct regmap *map = data->tempmon;
526
527 /*
528 * Need to disable thermal sensor, otherwise, when thermal core
529 * try to get temperature before thermal sensor resume, a wrong
530 * temperature will be read as the thermal sensor is powered
531 * down.
532 */
533 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
534 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
535 data->mode = THERMAL_DEVICE_DISABLED;
536
537 return 0;
538}
539
540static int imx_thermal_resume(struct device *dev)
541{
542 struct imx_thermal_data *data = dev_get_drvdata(dev);
543 struct regmap *map = data->tempmon;
544
545 /* Enabled thermal sensor after resume */
546 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
547 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
548 data->mode = THERMAL_DEVICE_ENABLED;
549
550 return 0;
551}
552#endif
553
554static SIMPLE_DEV_PM_OPS(imx_thermal_pm_ops,
555 imx_thermal_suspend, imx_thermal_resume);
556
557static const struct of_device_id of_imx_thermal_match[] = {
558 { .compatible = "fsl,imx6q-tempmon", },
559 { /* end */ }
560};
561MODULE_DEVICE_TABLE(of, of_imx_thermal_match);
562
563static struct platform_driver imx_thermal = {
564 .driver = {
565 .name = "imx_thermal",
566 .owner = THIS_MODULE,
567 .pm = &imx_thermal_pm_ops,
568 .of_match_table = of_imx_thermal_match,
569 },
570 .probe = imx_thermal_probe,
571 .remove = imx_thermal_remove,
572};
573module_platform_driver(imx_thermal);
574
575MODULE_AUTHOR("Freescale Semiconductor, Inc.");
576MODULE_DESCRIPTION("Thermal driver for Freescale i.MX SoCs");
577MODULE_LICENSE("GPL v2");
578MODULE_ALIAS("platform:imx-thermal");