aboutsummaryrefslogtreecommitdiff
path: root/drivers/platform/x86/intel_mid_thermal.c
blob: 3a578323122b7b18750de7d31ecb570b878cef43 (plain)
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
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
/*
 * intel_mid_thermal.c - Intel MID platform thermal driver
 *
 * Copyright (C) 2011 Intel Corporation
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.        See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 * Author: Durgadoss R <durgadoss.r@intel.com>
 */

#define pr_fmt(fmt) "intel_mid_thermal: " fmt

#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/param.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/pm.h>
#include <linux/thermal.h>

#include <asm/intel_scu_ipc.h>

/* Number of thermal sensors */
#define MSIC_THERMAL_SENSORS	4

/* ADC1 - thermal registers */
#define MSIC_THERM_ADC1CNTL1	0x1C0
#define MSIC_ADC_ENBL		0x10
#define MSIC_ADC_START		0x08

#define MSIC_THERM_ADC1CNTL3	0x1C2
#define MSIC_ADCTHERM_ENBL	0x04
#define MSIC_ADCRRDATA_ENBL	0x05
#define MSIC_CHANL_MASK_VAL	0x0F

#define MSIC_STOPBIT_MASK	16
#define MSIC_ADCTHERM_MASK	4
/* Number of ADC channels */
#define ADC_CHANLS_MAX		15
#define ADC_LOOP_MAX		(ADC_CHANLS_MAX - MSIC_THERMAL_SENSORS)

/* ADC channel code values */
#define SKIN_SENSOR0_CODE	0x08
#define SKIN_SENSOR1_CODE	0x09
#define SYS_SENSOR_CODE		0x0A
#define MSIC_DIE_SENSOR_CODE	0x03

#define SKIN_THERM_SENSOR0	0
#define SKIN_THERM_SENSOR1	1
#define SYS_THERM_SENSOR2	2
#define MSIC_DIE_THERM_SENSOR3	3

/* ADC code range */
#define ADC_MAX			977
#define ADC_MIN			162
#define ADC_VAL0C		887
#define ADC_VAL20C		720
#define ADC_VAL40C		508
#define ADC_VAL60C		315

/* ADC base addresses */
#define ADC_CHNL_START_ADDR	0x1C5	/* increments by 1 */
#define ADC_DATA_START_ADDR	0x1D4	/* increments by 2 */

/* MSIC die attributes */
#define MSIC_DIE_ADC_MIN	488
#define MSIC_DIE_ADC_MAX	1004

/* This holds the address of the first free ADC channel,
 * among the 15 channels
 */
static int channel_index;

struct platform_info {
	struct platform_device *pdev;
	struct thermal_zone_device *tzd[MSIC_THERMAL_SENSORS];
};

struct thermal_device_info {
	unsigned int chnl_addr;
	int direct;
	/* This holds the current temperature in millidegree celsius */
	long curr_temp;
};

/**
 * to_msic_die_temp - converts adc_val to msic_die temperature
 * @adc_val: ADC value to be converted
 *
 * Can sleep
 */
static int to_msic_die_temp(uint16_t adc_val)
{
	return (368 * (adc_val) / 1000) - 220;
}

/**
 * is_valid_adc - checks whether the adc code is within the defined range
 * @min: minimum value for the sensor
 * @max: maximum value for the sensor
 *
 * Can sleep
 */
static int is_valid_adc(uint16_t adc_val, uint16_t min, uint16_t max)
{
	return (adc_val >= min) && (adc_val <= max);
}

/**
 * adc_to_temp - converts the ADC code to temperature in C
 * @direct: true if ths channel is direct index
 * @adc_val: the adc_val that needs to be converted
 * @tp: temperature return value
 *
 * Linear approximation is used to covert the skin adc value into temperature.
 * This technique is used to avoid very long look-up table to get
 * the appropriate temp value from ADC value.
 * The adc code vs sensor temp curve is split into five parts
 * to achieve very close approximate temp value with less than
 * 0.5C error
 */
static int adc_to_temp(int direct, uint16_t adc_val, unsigned long *tp)
{
	int temp;

	/* Direct conversion for die temperature */
	if (direct) {
		if (is_valid_adc(adc_val, MSIC_DIE_ADC_MIN, MSIC_DIE_ADC_MAX)) {
			*tp = to_msic_die_temp(adc_val) * 1000;
			return 0;
		}
		return -ERANGE;
	}

	if (!is_valid_adc(adc_val, ADC_MIN, ADC_MAX))
		return -ERANGE;

	/* Linear approximation for skin temperature */
	if (adc_val > ADC_VAL0C)
		temp = 177 - (adc_val/5);
	else if ((adc_val <= ADC_VAL0C) && (adc_val > ADC_VAL20C))
		temp = 111 - (adc_val/8);
	else if ((adc_val <= ADC_VAL20C) && (adc_val > ADC_VAL40C))
		temp = 92 - (adc_val/10);
	else if ((adc_val <= ADC_VAL40C) && (adc_val > ADC_VAL60C))
		temp = 91 - (adc_val/10);
	else
		temp = 112 - (adc_val/6);

	/* Convert temperature in celsius to milli degree celsius */
	*tp = temp * 1000;
	return 0;
}

/**
 * mid_read_temp - read sensors for temperature
 * @temp: holds the current temperature for the sensor after reading
 *
 * reads the adc_code from the channel and converts it to real
 * temperature. The converted value is stored in temp.
 *
 * Can sleep
 */
static int mid_read_temp(struct thermal_zone_device *tzd, unsigned long *temp)
{
	struct thermal_device_info *td_info = tzd->devdata;
	uint16_t adc_val, addr;
	uint8_t data = 0;
	int ret;
	unsigned long curr_temp;


	addr = td_info->chnl_addr;

	/* Enable the msic for conversion before reading */
	ret = intel_scu_ipc_iowrite8(MSIC_THERM_ADC1CNTL3, MSIC_ADCRRDATA_ENBL);
	if (ret)
		return ret;

	/* Re-toggle the RRDATARD bit (temporary workaround) */
	ret = intel_scu_ipc_iowrite8(MSIC_THERM_ADC1CNTL3, MSIC_ADCTHERM_ENBL);
	if (ret)
		return ret;

	/* Read the higher bits of data */
	ret = intel_scu_ipc_ioread8(addr, &data);
	if (ret)
		return ret;

	/* Shift bits to accommodate the lower two data bits */
	adc_val = (data << 2);
	addr++;

	ret = intel_scu_ipc_ioread8(addr, &data);/* Read lower bits */
	if (ret)
		return ret;

	/* Adding lower two bits to the higher bits */
	data &= 03;
	adc_val += data;

	/* Convert ADC value to temperature */
	ret = adc_to_temp(td_info->direct, adc_val, &curr_temp);
	if (ret == 0)
		*temp = td_info->curr_temp = curr_temp;
	return ret;
}

/**
 * configure_adc - enables/disables the ADC for conversion
 * @val: zero: disables the ADC non-zero:enables the ADC
 *
 * Enable/Disable the ADC depending on the argument
 *
 * Can sleep
 */
static int configure_adc(int val)
{
	int ret;
	uint8_t data;

	ret = intel_scu_ipc_ioread8(MSIC_THERM_ADC1CNTL1, &data);
	if (ret)
		return ret;

	if (val) {
		/* Enable and start the ADC */
		data |= (MSIC_ADC_ENBL | MSIC_ADC_START);
	} else {
		/* Just stop the ADC */
		data &= (~MSIC_ADC_START);
	}
	return intel_scu_ipc_iowrite8(MSIC_THERM_ADC1CNTL1, data);
}

/**
 * set_up_therm_channel - enable thermal channel for conversion
 * @base_addr: index of free msic ADC channel
 *
 * Enable all the three channels for conversion
 *
 * Can sleep
 */
static int set_up_therm_channel(u16 base_addr)
{
	int ret;

	/* Enable all the sensor channels */
	ret = intel_scu_ipc_iowrite8(base_addr, SKIN_SENSOR0_CODE);
	if (ret)
		return ret;

	ret = intel_scu_ipc_iowrite8(base_addr + 1, SKIN_SENSOR1_CODE);
	if (ret)
		return ret;

	ret = intel_scu_ipc_iowrite8(base_addr + 2, SYS_SENSOR_CODE);
	if (ret)
		return ret;

	/* Since this is the last channel, set the stop bit
	 * to 1 by ORing the DIE_SENSOR_CODE with 0x10 */
	ret = intel_scu_ipc_iowrite8(base_addr + 3,
			(MSIC_DIE_SENSOR_CODE | 0x10));
	if (ret)
		return ret;

	/* Enable ADC and start it */
	return configure_adc(1);
}

/**
 * reset_stopbit - sets the stop bit to 0 on the given channel
 * @addr: address of the channel
 *
 * Can sleep
 */
static int reset_stopbit(uint16_t addr)
{
	int ret;
	uint8_t data;
	ret = intel_scu_ipc_ioread8(addr, &data);
	if (ret)
		return ret;
	/* Set the stop bit to zero */
	return intel_scu_ipc_iowrite8(addr, (data & 0xEF));
}

/**
 * find_free_channel - finds an empty channel for conversion
 *
 * If the ADC is not enabled then start using 0th channel
 * itself. Otherwise find an empty channel by looking for a
 * channel in which the stopbit is set to 1. returns the index
 * of the first free channel if succeeds or an error code.
 *
 * Context: can sleep
 *
 * FIXME: Ultimately the channel allocator will move into the intel_scu_ipc
 * code.
 */
static int find_free_channel(void)
{
	int ret;
	int i;
	uint8_t data;

	/* check whether ADC is enabled */
	ret = intel_scu_ipc_ioread8(MSIC_THERM_ADC1CNTL1, &data);
	if (ret)
		return ret;

	if ((data & MSIC_ADC_ENBL) == 0)
		return 0;

	/* ADC is already enabled; Looking for an empty channel */
	for (i = 0; i < ADC_CHANLS_MAX; i++) {
		ret = intel_scu_ipc_ioread8(ADC_CHNL_START_ADDR + i, &data);
		if (ret)
			return ret;

		if (data & MSIC_STOPBIT_MASK) {
			ret = i;
			break;
		}
	}
	return (ret > ADC_LOOP_MAX) ? (-EINVAL) : ret;
}

/**
 * mid_initialize_adc - initializing the ADC
 * @dev: our device structure
 *
 * Initialize the ADC for reading thermistor values. Can sleep.
 */
static int mid_initialize_adc(struct device *dev)
{
	u8  data;
	u16 base_addr;
	int ret;

	/*
	 * Ensure that adctherm is disabled before we
	 * initialize the ADC
	 */
	ret = intel_scu_ipc_ioread8(MSIC_THERM_ADC1CNTL3, &data);
	if (ret)
		return ret;

	if (data & MSIC_ADCTHERM_MASK)
		dev_warn(dev, "ADCTHERM already set");

	/* Index of the first channel in which the stop bit is set */
	channel_index = find_free_channel();
	if (channel_index < 0) {
		dev_err(dev, "No free ADC channels");
		return channel_index;
	}

	base_addr = ADC_CHNL_START_ADDR + channel_index;

	if (!(channel_index == 0 || channel_index == ADC_LOOP_MAX)) {
		/* Reset stop bit for channels other than 0 and 12 */
		ret = reset_stopbit(base_addr);
		if (ret)
			return ret;

		/* Index of the first free channel */
		base_addr++;
		channel_index++;
	}

	ret = set_up_therm_channel(base_addr);
	if (ret) {
		dev_err(dev, "unable to enable ADC");
		return ret;
	}
	dev_dbg(dev, "ADC initialization successful");
	return ret;
}

/**
 * initialize_sensor - sets default temp and timer ranges
 * @index: index of the sensor
 *
 * Context: can sleep
 */
static struct thermal_device_info *initialize_sensor(int index)
{
	struct thermal_device_info *td_info =
		kzalloc(sizeof(struct thermal_device_info), GFP_KERNEL);

	if (!td_info)
		return NULL;

	/* Set the base addr of the channel for this sensor */
	td_info->chnl_addr = ADC_DATA_START_ADDR + 2 * (channel_index + index);
	/* Sensor 3 is direct conversion */
	if (index == 3)
		td_info->direct = 1;
	return td_info;
}

/**
 * mid_thermal_resume - resume routine
 * @pdev: platform device structure
 *
 * mid thermal resume: re-initializes the adc. Can sleep.
 */
static int mid_thermal_resume(struct platform_device *pdev)
{
	return mid_initialize_adc(&pdev->dev);
}

/**
 * mid_thermal_suspend - suspend routine
 * @pdev: platform device structure
 *
 * mid thermal suspend implements the suspend functionality
 * by stopping the ADC. Can sleep.
 */
static int mid_thermal_suspend(struct platform_device *pdev, pm_message_t mesg)
{
	/*
	 * This just stops the ADC and does not disable it.
	 * temporary workaround until we have a generic ADC driver.
	 * If 0 is passed, it disables the ADC.
	 */
	return configure_adc(0);
}

/**
 * read_curr_temp - reads the current temperature and stores in temp
 * @temp: holds the current temperature value after reading
 *
 * Can sleep
 */
static int read_curr_temp(struct thermal_zone_device *tzd, unsigned long *temp)
{
	WARN_ON(tzd == NULL);
	return mid_read_temp(tzd, temp);
}

/* Can't be const */
static struct thermal_zone_device_ops tzd_ops = {
	.get_temp = read_curr_temp,
};

/**
 * mid_thermal_probe - mfld thermal initialize
 * @pdev: platform device structure
 *
 * mid thermal probe initializes the hardware and registers
 * all the sensors with the generic thermal framework. Can sleep.
 */
static int mid_thermal_probe(struct platform_device *pdev)
{
	static char *name[MSIC_THERMAL_SENSORS] = {
		"skin0", "skin1", "sys", "msicdie"
	};

	int ret;
	int i;
	struct platform_info *pinfo;

	pinfo = kzalloc(sizeof(struct platform_info), GFP_KERNEL);
	if (!pinfo)
		return -ENOMEM;

	/* Initializing the hardware */
	ret = mid_initialize_adc(&pdev->dev);
	if (ret) {
		dev_err(&pdev->dev, "ADC init failed");
		kfree(pinfo);
		return ret;
	}

	/* Register each sensor with the generic thermal framework*/
	for (i = 0; i < MSIC_THERMAL_SENSORS; i++) {
		pinfo->tzd[i] = thermal_zone_device_register(name[i],
				0, initialize_sensor(i), &tzd_ops, 0, 0, 0, 0);
		if (IS_ERR(pinfo->tzd[i]))
			goto reg_fail;
	}

	pinfo->pdev = pdev;
	platform_set_drvdata(pdev, pinfo);
	return 0;

reg_fail:
	ret = PTR_ERR(pinfo->tzd[i]);
	while (--i >= 0)
		thermal_zone_device_unregister(pinfo->tzd[i]);
	configure_adc(0);
	kfree(pinfo);
	return ret;
}

/**
 * mid_thermal_remove - mfld thermal finalize
 * @dev: platform device structure
 *
 * MLFD thermal remove unregisters all the sensors from the generic
 * thermal framework. Can sleep.
 */
static int mid_thermal_remove(struct platform_device *pdev)
{
	int i;
	struct platform_info *pinfo = platform_get_drvdata(pdev);

	for (i = 0; i < MSIC_THERMAL_SENSORS; i++)
		thermal_zone_device_unregister(pinfo->tzd[i]);

	kfree(pinfo);
	platform_set_drvdata(pdev, NULL);

	/* Stop the ADC */
	return configure_adc(0);
}

#define DRIVER_NAME "msic_sensor"

static const struct platform_device_id therm_id_table[] = {
	{ DRIVER_NAME, 1 },
	{ }
};

static struct platform_driver mid_thermal_driver = {
	.driver = {
		.name = DRIVER_NAME,
		.owner = THIS_MODULE,
	},
	.probe = mid_thermal_probe,
	.suspend = mid_thermal_suspend,
	.resume = mid_thermal_resume,
	.remove = __devexit_p(mid_thermal_remove),
	.id_table = therm_id_table,
};

static int __init mid_thermal_module_init(void)
{
	return platform_driver_register(&mid_thermal_driver);
}

static void __exit mid_thermal_module_exit(void)
{
	platform_driver_unregister(&mid_thermal_driver);
}

module_init(mid_thermal_module_init);
module_exit(mid_thermal_module_exit);

MODULE_AUTHOR("Durgadoss R <durgadoss.r@intel.com>");
MODULE_DESCRIPTION("Intel Medfield Platform Thermal Driver");
MODULE_LICENSE("GPL");