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1/*
2 * intel_mid_thermal.c - Intel MID platform thermal driver
3 *
4 * Copyright (C) 2011 Intel Corporation
5 *
6 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; version 2 of the License.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, write to the Free Software Foundation, Inc.,
19 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
20 *
21 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
22 * Author: Durgadoss R <durgadoss.r@intel.com>
23 */
24
25#define pr_fmt(fmt) "intel_mid_thermal: " fmt
26
27#include <linux/module.h>
28#include <linux/init.h>
29#include <linux/err.h>
30#include <linux/param.h>
31#include <linux/device.h>
32#include <linux/platform_device.h>
33#include <linux/slab.h>
34#include <linux/pm.h>
35#include <linux/thermal.h>
36
37#include <asm/intel_scu_ipc.h>
38
39/* Number of thermal sensors */
40#define MSIC_THERMAL_SENSORS 4
41
42/* ADC1 - thermal registers */
43#define MSIC_THERM_ADC1CNTL1 0x1C0
44#define MSIC_ADC_ENBL 0x10
45#define MSIC_ADC_START 0x08
46
47#define MSIC_THERM_ADC1CNTL3 0x1C2
48#define MSIC_ADCTHERM_ENBL 0x04
49#define MSIC_ADCRRDATA_ENBL 0x05
50#define MSIC_CHANL_MASK_VAL 0x0F
51
52#define MSIC_STOPBIT_MASK 16
53#define MSIC_ADCTHERM_MASK 4
54/* Number of ADC channels */
55#define ADC_CHANLS_MAX 15
56#define ADC_LOOP_MAX (ADC_CHANLS_MAX - MSIC_THERMAL_SENSORS)
57
58/* ADC channel code values */
59#define SKIN_SENSOR0_CODE 0x08
60#define SKIN_SENSOR1_CODE 0x09
61#define SYS_SENSOR_CODE 0x0A
62#define MSIC_DIE_SENSOR_CODE 0x03
63
64#define SKIN_THERM_SENSOR0 0
65#define SKIN_THERM_SENSOR1 1
66#define SYS_THERM_SENSOR2 2
67#define MSIC_DIE_THERM_SENSOR3 3
68
69/* ADC code range */
70#define ADC_MAX 977
71#define ADC_MIN 162
72#define ADC_VAL0C 887
73#define ADC_VAL20C 720
74#define ADC_VAL40C 508
75#define ADC_VAL60C 315
76
77/* ADC base addresses */
78#define ADC_CHNL_START_ADDR 0x1C5 /* increments by 1 */
79#define ADC_DATA_START_ADDR 0x1D4 /* increments by 2 */
80
81/* MSIC die attributes */
82#define MSIC_DIE_ADC_MIN 488
83#define MSIC_DIE_ADC_MAX 1004
84
85/* This holds the address of the first free ADC channel,
86 * among the 15 channels
87 */
88static int channel_index;
89
90struct platform_info {
91 struct platform_device *pdev;
92 struct thermal_zone_device *tzd[MSIC_THERMAL_SENSORS];
93};
94
95struct thermal_device_info {
96 unsigned int chnl_addr;
97 int direct;
98 /* This holds the current temperature in millidegree celsius */
99 long curr_temp;
100};
101
102/**
103 * to_msic_die_temp - converts adc_val to msic_die temperature
104 * @adc_val: ADC value to be converted
105 *
106 * Can sleep
107 */
108static int to_msic_die_temp(uint16_t adc_val)
109{
110 return (368 * (adc_val) / 1000) - 220;
111}
112
113/**
114 * is_valid_adc - checks whether the adc code is within the defined range
115 * @min: minimum value for the sensor
116 * @max: maximum value for the sensor
117 *
118 * Can sleep
119 */
120static int is_valid_adc(uint16_t adc_val, uint16_t min, uint16_t max)
121{
122 return (adc_val >= min) && (adc_val <= max);
123}
124
125/**
126 * adc_to_temp - converts the ADC code to temperature in C
127 * @direct: true if ths channel is direct index
128 * @adc_val: the adc_val that needs to be converted
129 * @tp: temperature return value
130 *
131 * Linear approximation is used to covert the skin adc value into temperature.
132 * This technique is used to avoid very long look-up table to get
133 * the appropriate temp value from ADC value.
134 * The adc code vs sensor temp curve is split into five parts
135 * to achieve very close approximate temp value with less than
136 * 0.5C error
137 */
138static int adc_to_temp(int direct, uint16_t adc_val, unsigned long *tp)
139{
140 int temp;
141
142 /* Direct conversion for die temperature */
143 if (direct) {
144 if (is_valid_adc(adc_val, MSIC_DIE_ADC_MIN, MSIC_DIE_ADC_MAX)) {
145 *tp = to_msic_die_temp(adc_val) * 1000;
146 return 0;
147 }
148 return -ERANGE;
149 }
150
151 if (!is_valid_adc(adc_val, ADC_MIN, ADC_MAX))
152 return -ERANGE;
153
154 /* Linear approximation for skin temperature */
155 if (adc_val > ADC_VAL0C)
156 temp = 177 - (adc_val/5);
157 else if ((adc_val <= ADC_VAL0C) && (adc_val > ADC_VAL20C))
158 temp = 111 - (adc_val/8);
159 else if ((adc_val <= ADC_VAL20C) && (adc_val > ADC_VAL40C))
160 temp = 92 - (adc_val/10);
161 else if ((adc_val <= ADC_VAL40C) && (adc_val > ADC_VAL60C))
162 temp = 91 - (adc_val/10);
163 else
164 temp = 112 - (adc_val/6);
165
166 /* Convert temperature in celsius to milli degree celsius */
167 *tp = temp * 1000;
168 return 0;
169}
170
171/**
172 * mid_read_temp - read sensors for temperature
173 * @temp: holds the current temperature for the sensor after reading
174 *
175 * reads the adc_code from the channel and converts it to real
176 * temperature. The converted value is stored in temp.
177 *
178 * Can sleep
179 */
180static int mid_read_temp(struct thermal_zone_device *tzd, unsigned long *temp)
181{
182 struct thermal_device_info *td_info = tzd->devdata;
183 uint16_t adc_val, addr;
184 uint8_t data = 0;
185 int ret;
186 unsigned long curr_temp;
187
188
189 addr = td_info->chnl_addr;
190
191 /* Enable the msic for conversion before reading */
192 ret = intel_scu_ipc_iowrite8(MSIC_THERM_ADC1CNTL3, MSIC_ADCRRDATA_ENBL);
193 if (ret)
194 return ret;
195
196 /* Re-toggle the RRDATARD bit (temporary workaround) */
197 ret = intel_scu_ipc_iowrite8(MSIC_THERM_ADC1CNTL3, MSIC_ADCTHERM_ENBL);
198 if (ret)
199 return ret;
200
201 /* Read the higher bits of data */
202 ret = intel_scu_ipc_ioread8(addr, &data);
203 if (ret)
204 return ret;
205
206 /* Shift bits to accommodate the lower two data bits */
207 adc_val = (data << 2);
208 addr++;
209
210 ret = intel_scu_ipc_ioread8(addr, &data);/* Read lower bits */
211 if (ret)
212 return ret;
213
214 /* Adding lower two bits to the higher bits */
215 data &= 03;
216 adc_val += data;
217
218 /* Convert ADC value to temperature */
219 ret = adc_to_temp(td_info->direct, adc_val, &curr_temp);
220 if (ret == 0)
221 *temp = td_info->curr_temp = curr_temp;
222 return ret;
223}
224
225/**
226 * configure_adc - enables/disables the ADC for conversion
227 * @val: zero: disables the ADC non-zero:enables the ADC
228 *
229 * Enable/Disable the ADC depending on the argument
230 *
231 * Can sleep
232 */
233static int configure_adc(int val)
234{
235 int ret;
236 uint8_t data;
237
238 ret = intel_scu_ipc_ioread8(MSIC_THERM_ADC1CNTL1, &data);
239 if (ret)
240 return ret;
241
242 if (val) {
243 /* Enable and start the ADC */
244 data |= (MSIC_ADC_ENBL | MSIC_ADC_START);
245 } else {
246 /* Just stop the ADC */
247 data &= (~MSIC_ADC_START);
248 }
249 return intel_scu_ipc_iowrite8(MSIC_THERM_ADC1CNTL1, data);
250}
251
252/**
253 * set_up_therm_channel - enable thermal channel for conversion
254 * @base_addr: index of free msic ADC channel
255 *
256 * Enable all the three channels for conversion
257 *
258 * Can sleep
259 */
260static int set_up_therm_channel(u16 base_addr)
261{
262 int ret;
263
264 /* Enable all the sensor channels */
265 ret = intel_scu_ipc_iowrite8(base_addr, SKIN_SENSOR0_CODE);
266 if (ret)
267 return ret;
268
269 ret = intel_scu_ipc_iowrite8(base_addr + 1, SKIN_SENSOR1_CODE);
270 if (ret)
271 return ret;
272
273 ret = intel_scu_ipc_iowrite8(base_addr + 2, SYS_SENSOR_CODE);
274 if (ret)
275 return ret;
276
277 /* Since this is the last channel, set the stop bit
278 * to 1 by ORing the DIE_SENSOR_CODE with 0x10 */
279 ret = intel_scu_ipc_iowrite8(base_addr + 3,
280 (MSIC_DIE_SENSOR_CODE | 0x10));
281 if (ret)
282 return ret;
283
284 /* Enable ADC and start it */
285 return configure_adc(1);
286}
287
288/**
289 * reset_stopbit - sets the stop bit to 0 on the given channel
290 * @addr: address of the channel
291 *
292 * Can sleep
293 */
294static int reset_stopbit(uint16_t addr)
295{
296 int ret;
297 uint8_t data;
298 ret = intel_scu_ipc_ioread8(addr, &data);
299 if (ret)
300 return ret;
301 /* Set the stop bit to zero */
302 return intel_scu_ipc_iowrite8(addr, (data & 0xEF));
303}
304
305/**
306 * find_free_channel - finds an empty channel for conversion
307 *
308 * If the ADC is not enabled then start using 0th channel
309 * itself. Otherwise find an empty channel by looking for a
310 * channel in which the stopbit is set to 1. returns the index
311 * of the first free channel if succeeds or an error code.
312 *
313 * Context: can sleep
314 *
315 * FIXME: Ultimately the channel allocator will move into the intel_scu_ipc
316 * code.
317 */
318static int find_free_channel(void)
319{
320 int ret;
321 int i;
322 uint8_t data;
323
324 /* check whether ADC is enabled */
325 ret = intel_scu_ipc_ioread8(MSIC_THERM_ADC1CNTL1, &data);
326 if (ret)
327 return ret;
328
329 if ((data & MSIC_ADC_ENBL) == 0)
330 return 0;
331
332 /* ADC is already enabled; Looking for an empty channel */
333 for (i = 0; i < ADC_CHANLS_MAX; i++) {
334 ret = intel_scu_ipc_ioread8(ADC_CHNL_START_ADDR + i, &data);
335 if (ret)
336 return ret;
337
338 if (data & MSIC_STOPBIT_MASK) {
339 ret = i;
340 break;
341 }
342 }
343 return (ret > ADC_LOOP_MAX) ? (-EINVAL) : ret;
344}
345
346/**
347 * mid_initialize_adc - initializing the ADC
348 * @dev: our device structure
349 *
350 * Initialize the ADC for reading thermistor values. Can sleep.
351 */
352static int mid_initialize_adc(struct device *dev)
353{
354 u8 data;
355 u16 base_addr;
356 int ret;
357
358 /*
359 * Ensure that adctherm is disabled before we
360 * initialize the ADC
361 */
362 ret = intel_scu_ipc_ioread8(MSIC_THERM_ADC1CNTL3, &data);
363 if (ret)
364 return ret;
365
366 if (data & MSIC_ADCTHERM_MASK)
367 dev_warn(dev, "ADCTHERM already set");
368
369 /* Index of the first channel in which the stop bit is set */
370 channel_index = find_free_channel();
371 if (channel_index < 0) {
372 dev_err(dev, "No free ADC channels");
373 return channel_index;
374 }
375
376 base_addr = ADC_CHNL_START_ADDR + channel_index;
377
378 if (!(channel_index == 0 || channel_index == ADC_LOOP_MAX)) {
379 /* Reset stop bit for channels other than 0 and 12 */
380 ret = reset_stopbit(base_addr);
381 if (ret)
382 return ret;
383
384 /* Index of the first free channel */
385 base_addr++;
386 channel_index++;
387 }
388
389 ret = set_up_therm_channel(base_addr);
390 if (ret) {
391 dev_err(dev, "unable to enable ADC");
392 return ret;
393 }
394 dev_dbg(dev, "ADC initialization successful");
395 return ret;
396}
397
398/**
399 * initialize_sensor - sets default temp and timer ranges
400 * @index: index of the sensor
401 *
402 * Context: can sleep
403 */
404static struct thermal_device_info *initialize_sensor(int index)
405{
406 struct thermal_device_info *td_info =
407 kzalloc(sizeof(struct thermal_device_info), GFP_KERNEL);
408
409 if (!td_info)
410 return NULL;
411
412 /* Set the base addr of the channel for this sensor */
413 td_info->chnl_addr = ADC_DATA_START_ADDR + 2 * (channel_index + index);
414 /* Sensor 3 is direct conversion */
415 if (index == 3)
416 td_info->direct = 1;
417 return td_info;
418}
419
420/**
421 * mid_thermal_resume - resume routine
422 * @pdev: platform device structure
423 *
424 * mid thermal resume: re-initializes the adc. Can sleep.
425 */
426static int mid_thermal_resume(struct platform_device *pdev)
427{
428 return mid_initialize_adc(&pdev->dev);
429}
430
431/**
432 * mid_thermal_suspend - suspend routine
433 * @pdev: platform device structure
434 *
435 * mid thermal suspend implements the suspend functionality
436 * by stopping the ADC. Can sleep.
437 */
438static int mid_thermal_suspend(struct platform_device *pdev, pm_message_t mesg)
439{
440 /*
441 * This just stops the ADC and does not disable it.
442 * temporary workaround until we have a generic ADC driver.
443 * If 0 is passed, it disables the ADC.
444 */
445 return configure_adc(0);
446}
447
448/**
449 * read_curr_temp - reads the current temperature and stores in temp
450 * @temp: holds the current temperature value after reading
451 *
452 * Can sleep
453 */
454static int read_curr_temp(struct thermal_zone_device *tzd, unsigned long *temp)
455{
456 WARN_ON(tzd == NULL);
457 return mid_read_temp(tzd, temp);
458}
459
460/* Can't be const */
461static struct thermal_zone_device_ops tzd_ops = {
462 .get_temp = read_curr_temp,
463};
464
465/**
466 * mid_thermal_probe - mfld thermal initialize
467 * @pdev: platform device structure
468 *
469 * mid thermal probe initializes the hardware and registers
470 * all the sensors with the generic thermal framework. Can sleep.
471 */
472static int mid_thermal_probe(struct platform_device *pdev)
473{
474 static char *name[MSIC_THERMAL_SENSORS] = {
475 "skin0", "skin1", "sys", "msicdie"
476 };
477
478 int ret;
479 int i;
480 struct platform_info *pinfo;
481
482 pinfo = kzalloc(sizeof(struct platform_info), GFP_KERNEL);
483 if (!pinfo)
484 return -ENOMEM;
485
486 /* Initializing the hardware */
487 ret = mid_initialize_adc(&pdev->dev);
488 if (ret) {
489 dev_err(&pdev->dev, "ADC init failed");
490 kfree(pinfo);
491 return ret;
492 }
493
494 /* Register each sensor with the generic thermal framework*/
495 for (i = 0; i < MSIC_THERMAL_SENSORS; i++) {
496 struct thermal_device_info *td_info = initialize_sensor(i);
497
498 if (!td_info) {
499 ret = -ENOMEM;
500 goto err;
501 }
502 pinfo->tzd[i] = thermal_zone_device_register(name[i],
503 0, td_info, &tzd_ops, 0, 0, 0, 0);
504 if (IS_ERR(pinfo->tzd[i])) {
505 kfree(td_info);
506 ret = PTR_ERR(pinfo->tzd[i]);
507 goto err;
508 }
509 }
510
511 pinfo->pdev = pdev;
512 platform_set_drvdata(pdev, pinfo);
513 return 0;
514
515err:
516 while (--i >= 0) {
517 kfree(pinfo->tzd[i]->devdata);
518 thermal_zone_device_unregister(pinfo->tzd[i]);
519 }
520 configure_adc(0);
521 kfree(pinfo);
522 return ret;
523}
524
525/**
526 * mid_thermal_remove - mfld thermal finalize
527 * @dev: platform device structure
528 *
529 * MLFD thermal remove unregisters all the sensors from the generic
530 * thermal framework. Can sleep.
531 */
532static int mid_thermal_remove(struct platform_device *pdev)
533{
534 int i;
535 struct platform_info *pinfo = platform_get_drvdata(pdev);
536
537 for (i = 0; i < MSIC_THERMAL_SENSORS; i++) {
538 kfree(pinfo->tzd[i]->devdata);
539 thermal_zone_device_unregister(pinfo->tzd[i]);
540 }
541
542 kfree(pinfo);
543 platform_set_drvdata(pdev, NULL);
544
545 /* Stop the ADC */
546 return configure_adc(0);
547}
548
549#define DRIVER_NAME "msic_sensor"
550
551static const struct platform_device_id therm_id_table[] = {
552 { DRIVER_NAME, 1 },
553 { }
554};
555
556static struct platform_driver mid_thermal_driver = {
557 .driver = {
558 .name = DRIVER_NAME,
559 .owner = THIS_MODULE,
560 },
561 .probe = mid_thermal_probe,
562 .suspend = mid_thermal_suspend,
563 .resume = mid_thermal_resume,
564 .remove = __devexit_p(mid_thermal_remove),
565 .id_table = therm_id_table,
566};
567
568static int __init mid_thermal_module_init(void)
569{
570 return platform_driver_register(&mid_thermal_driver);
571}
572
573static void __exit mid_thermal_module_exit(void)
574{
575 platform_driver_unregister(&mid_thermal_driver);
576}
577
578module_init(mid_thermal_module_init);
579module_exit(mid_thermal_module_exit);
580
581MODULE_AUTHOR("Durgadoss R <durgadoss.r@intel.com>");
582MODULE_DESCRIPTION("Intel Medfield Platform Thermal Driver");
583MODULE_LICENSE("GPL");
1/*
2 * intel_mid_thermal.c - Intel MID platform thermal driver
3 *
4 * Copyright (C) 2011 Intel Corporation
5 *
6 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; version 2 of the License.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, write to the Free Software Foundation, Inc.,
19 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
20 *
21 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
22 * Author: Durgadoss R <durgadoss.r@intel.com>
23 */
24
25#define pr_fmt(fmt) "intel_mid_thermal: " fmt
26
27#include <linux/module.h>
28#include <linux/init.h>
29#include <linux/err.h>
30#include <linux/param.h>
31#include <linux/device.h>
32#include <linux/platform_device.h>
33#include <linux/slab.h>
34#include <linux/pm.h>
35#include <linux/thermal.h>
36#include <linux/mfd/intel_msic.h>
37
38/* Number of thermal sensors */
39#define MSIC_THERMAL_SENSORS 4
40
41/* ADC1 - thermal registers */
42#define MSIC_ADC_ENBL 0x10
43#define MSIC_ADC_START 0x08
44
45#define MSIC_ADCTHERM_ENBL 0x04
46#define MSIC_ADCRRDATA_ENBL 0x05
47#define MSIC_CHANL_MASK_VAL 0x0F
48
49#define MSIC_STOPBIT_MASK 16
50#define MSIC_ADCTHERM_MASK 4
51/* Number of ADC channels */
52#define ADC_CHANLS_MAX 15
53#define ADC_LOOP_MAX (ADC_CHANLS_MAX - MSIC_THERMAL_SENSORS)
54
55/* ADC channel code values */
56#define SKIN_SENSOR0_CODE 0x08
57#define SKIN_SENSOR1_CODE 0x09
58#define SYS_SENSOR_CODE 0x0A
59#define MSIC_DIE_SENSOR_CODE 0x03
60
61#define SKIN_THERM_SENSOR0 0
62#define SKIN_THERM_SENSOR1 1
63#define SYS_THERM_SENSOR2 2
64#define MSIC_DIE_THERM_SENSOR3 3
65
66/* ADC code range */
67#define ADC_MAX 977
68#define ADC_MIN 162
69#define ADC_VAL0C 887
70#define ADC_VAL20C 720
71#define ADC_VAL40C 508
72#define ADC_VAL60C 315
73
74/* ADC base addresses */
75#define ADC_CHNL_START_ADDR INTEL_MSIC_ADC1ADDR0 /* increments by 1 */
76#define ADC_DATA_START_ADDR INTEL_MSIC_ADC1SNS0H /* increments by 2 */
77
78/* MSIC die attributes */
79#define MSIC_DIE_ADC_MIN 488
80#define MSIC_DIE_ADC_MAX 1004
81
82/* This holds the address of the first free ADC channel,
83 * among the 15 channels
84 */
85static int channel_index;
86
87struct platform_info {
88 struct platform_device *pdev;
89 struct thermal_zone_device *tzd[MSIC_THERMAL_SENSORS];
90};
91
92struct thermal_device_info {
93 unsigned int chnl_addr;
94 int direct;
95 /* This holds the current temperature in millidegree celsius */
96 long curr_temp;
97};
98
99/**
100 * to_msic_die_temp - converts adc_val to msic_die temperature
101 * @adc_val: ADC value to be converted
102 *
103 * Can sleep
104 */
105static int to_msic_die_temp(uint16_t adc_val)
106{
107 return (368 * (adc_val) / 1000) - 220;
108}
109
110/**
111 * is_valid_adc - checks whether the adc code is within the defined range
112 * @min: minimum value for the sensor
113 * @max: maximum value for the sensor
114 *
115 * Can sleep
116 */
117static int is_valid_adc(uint16_t adc_val, uint16_t min, uint16_t max)
118{
119 return (adc_val >= min) && (adc_val <= max);
120}
121
122/**
123 * adc_to_temp - converts the ADC code to temperature in C
124 * @direct: true if ths channel is direct index
125 * @adc_val: the adc_val that needs to be converted
126 * @tp: temperature return value
127 *
128 * Linear approximation is used to covert the skin adc value into temperature.
129 * This technique is used to avoid very long look-up table to get
130 * the appropriate temp value from ADC value.
131 * The adc code vs sensor temp curve is split into five parts
132 * to achieve very close approximate temp value with less than
133 * 0.5C error
134 */
135static int adc_to_temp(int direct, uint16_t adc_val, int *tp)
136{
137 int temp;
138
139 /* Direct conversion for die temperature */
140 if (direct) {
141 if (is_valid_adc(adc_val, MSIC_DIE_ADC_MIN, MSIC_DIE_ADC_MAX)) {
142 *tp = to_msic_die_temp(adc_val) * 1000;
143 return 0;
144 }
145 return -ERANGE;
146 }
147
148 if (!is_valid_adc(adc_val, ADC_MIN, ADC_MAX))
149 return -ERANGE;
150
151 /* Linear approximation for skin temperature */
152 if (adc_val > ADC_VAL0C)
153 temp = 177 - (adc_val/5);
154 else if ((adc_val <= ADC_VAL0C) && (adc_val > ADC_VAL20C))
155 temp = 111 - (adc_val/8);
156 else if ((adc_val <= ADC_VAL20C) && (adc_val > ADC_VAL40C))
157 temp = 92 - (adc_val/10);
158 else if ((adc_val <= ADC_VAL40C) && (adc_val > ADC_VAL60C))
159 temp = 91 - (adc_val/10);
160 else
161 temp = 112 - (adc_val/6);
162
163 /* Convert temperature in celsius to milli degree celsius */
164 *tp = temp * 1000;
165 return 0;
166}
167
168/**
169 * mid_read_temp - read sensors for temperature
170 * @temp: holds the current temperature for the sensor after reading
171 *
172 * reads the adc_code from the channel and converts it to real
173 * temperature. The converted value is stored in temp.
174 *
175 * Can sleep
176 */
177static int mid_read_temp(struct thermal_zone_device *tzd, int *temp)
178{
179 struct thermal_device_info *td_info = tzd->devdata;
180 uint16_t adc_val, addr;
181 uint8_t data = 0;
182 int ret;
183 int curr_temp;
184
185 addr = td_info->chnl_addr;
186
187 /* Enable the msic for conversion before reading */
188 ret = intel_msic_reg_write(INTEL_MSIC_ADC1CNTL3, MSIC_ADCRRDATA_ENBL);
189 if (ret)
190 return ret;
191
192 /* Re-toggle the RRDATARD bit (temporary workaround) */
193 ret = intel_msic_reg_write(INTEL_MSIC_ADC1CNTL3, MSIC_ADCTHERM_ENBL);
194 if (ret)
195 return ret;
196
197 /* Read the higher bits of data */
198 ret = intel_msic_reg_read(addr, &data);
199 if (ret)
200 return ret;
201
202 /* Shift bits to accommodate the lower two data bits */
203 adc_val = (data << 2);
204 addr++;
205
206 ret = intel_msic_reg_read(addr, &data);/* Read lower bits */
207 if (ret)
208 return ret;
209
210 /* Adding lower two bits to the higher bits */
211 data &= 03;
212 adc_val += data;
213
214 /* Convert ADC value to temperature */
215 ret = adc_to_temp(td_info->direct, adc_val, &curr_temp);
216 if (ret == 0)
217 *temp = td_info->curr_temp = curr_temp;
218 return ret;
219}
220
221/**
222 * configure_adc - enables/disables the ADC for conversion
223 * @val: zero: disables the ADC non-zero:enables the ADC
224 *
225 * Enable/Disable the ADC depending on the argument
226 *
227 * Can sleep
228 */
229static int configure_adc(int val)
230{
231 int ret;
232 uint8_t data;
233
234 ret = intel_msic_reg_read(INTEL_MSIC_ADC1CNTL1, &data);
235 if (ret)
236 return ret;
237
238 if (val) {
239 /* Enable and start the ADC */
240 data |= (MSIC_ADC_ENBL | MSIC_ADC_START);
241 } else {
242 /* Just stop the ADC */
243 data &= (~MSIC_ADC_START);
244 }
245 return intel_msic_reg_write(INTEL_MSIC_ADC1CNTL1, data);
246}
247
248/**
249 * set_up_therm_channel - enable thermal channel for conversion
250 * @base_addr: index of free msic ADC channel
251 *
252 * Enable all the three channels for conversion
253 *
254 * Can sleep
255 */
256static int set_up_therm_channel(u16 base_addr)
257{
258 int ret;
259
260 /* Enable all the sensor channels */
261 ret = intel_msic_reg_write(base_addr, SKIN_SENSOR0_CODE);
262 if (ret)
263 return ret;
264
265 ret = intel_msic_reg_write(base_addr + 1, SKIN_SENSOR1_CODE);
266 if (ret)
267 return ret;
268
269 ret = intel_msic_reg_write(base_addr + 2, SYS_SENSOR_CODE);
270 if (ret)
271 return ret;
272
273 /* Since this is the last channel, set the stop bit
274 * to 1 by ORing the DIE_SENSOR_CODE with 0x10 */
275 ret = intel_msic_reg_write(base_addr + 3,
276 (MSIC_DIE_SENSOR_CODE | 0x10));
277 if (ret)
278 return ret;
279
280 /* Enable ADC and start it */
281 return configure_adc(1);
282}
283
284/**
285 * reset_stopbit - sets the stop bit to 0 on the given channel
286 * @addr: address of the channel
287 *
288 * Can sleep
289 */
290static int reset_stopbit(uint16_t addr)
291{
292 int ret;
293 uint8_t data;
294 ret = intel_msic_reg_read(addr, &data);
295 if (ret)
296 return ret;
297 /* Set the stop bit to zero */
298 return intel_msic_reg_write(addr, (data & 0xEF));
299}
300
301/**
302 * find_free_channel - finds an empty channel for conversion
303 *
304 * If the ADC is not enabled then start using 0th channel
305 * itself. Otherwise find an empty channel by looking for a
306 * channel in which the stopbit is set to 1. returns the index
307 * of the first free channel if succeeds or an error code.
308 *
309 * Context: can sleep
310 *
311 * FIXME: Ultimately the channel allocator will move into the intel_scu_ipc
312 * code.
313 */
314static int find_free_channel(void)
315{
316 int ret;
317 int i;
318 uint8_t data;
319
320 /* check whether ADC is enabled */
321 ret = intel_msic_reg_read(INTEL_MSIC_ADC1CNTL1, &data);
322 if (ret)
323 return ret;
324
325 if ((data & MSIC_ADC_ENBL) == 0)
326 return 0;
327
328 /* ADC is already enabled; Looking for an empty channel */
329 for (i = 0; i < ADC_CHANLS_MAX; i++) {
330 ret = intel_msic_reg_read(ADC_CHNL_START_ADDR + i, &data);
331 if (ret)
332 return ret;
333
334 if (data & MSIC_STOPBIT_MASK) {
335 ret = i;
336 break;
337 }
338 }
339 return (ret > ADC_LOOP_MAX) ? (-EINVAL) : ret;
340}
341
342/**
343 * mid_initialize_adc - initializing the ADC
344 * @dev: our device structure
345 *
346 * Initialize the ADC for reading thermistor values. Can sleep.
347 */
348static int mid_initialize_adc(struct device *dev)
349{
350 u8 data;
351 u16 base_addr;
352 int ret;
353
354 /*
355 * Ensure that adctherm is disabled before we
356 * initialize the ADC
357 */
358 ret = intel_msic_reg_read(INTEL_MSIC_ADC1CNTL3, &data);
359 if (ret)
360 return ret;
361
362 data &= ~MSIC_ADCTHERM_MASK;
363 ret = intel_msic_reg_write(INTEL_MSIC_ADC1CNTL3, data);
364 if (ret)
365 return ret;
366
367 /* Index of the first channel in which the stop bit is set */
368 channel_index = find_free_channel();
369 if (channel_index < 0) {
370 dev_err(dev, "No free ADC channels");
371 return channel_index;
372 }
373
374 base_addr = ADC_CHNL_START_ADDR + channel_index;
375
376 if (!(channel_index == 0 || channel_index == ADC_LOOP_MAX)) {
377 /* Reset stop bit for channels other than 0 and 12 */
378 ret = reset_stopbit(base_addr);
379 if (ret)
380 return ret;
381
382 /* Index of the first free channel */
383 base_addr++;
384 channel_index++;
385 }
386
387 ret = set_up_therm_channel(base_addr);
388 if (ret) {
389 dev_err(dev, "unable to enable ADC");
390 return ret;
391 }
392 dev_dbg(dev, "ADC initialization successful");
393 return ret;
394}
395
396/**
397 * initialize_sensor - sets default temp and timer ranges
398 * @index: index of the sensor
399 *
400 * Context: can sleep
401 */
402static struct thermal_device_info *initialize_sensor(int index)
403{
404 struct thermal_device_info *td_info =
405 kzalloc(sizeof(struct thermal_device_info), GFP_KERNEL);
406
407 if (!td_info)
408 return NULL;
409
410 /* Set the base addr of the channel for this sensor */
411 td_info->chnl_addr = ADC_DATA_START_ADDR + 2 * (channel_index + index);
412 /* Sensor 3 is direct conversion */
413 if (index == 3)
414 td_info->direct = 1;
415 return td_info;
416}
417
418#ifdef CONFIG_PM_SLEEP
419/**
420 * mid_thermal_resume - resume routine
421 * @dev: device structure
422 *
423 * mid thermal resume: re-initializes the adc. Can sleep.
424 */
425static int mid_thermal_resume(struct device *dev)
426{
427 return mid_initialize_adc(dev);
428}
429
430/**
431 * mid_thermal_suspend - suspend routine
432 * @dev: device structure
433 *
434 * mid thermal suspend implements the suspend functionality
435 * by stopping the ADC. Can sleep.
436 */
437static int mid_thermal_suspend(struct device *dev)
438{
439 /*
440 * This just stops the ADC and does not disable it.
441 * temporary workaround until we have a generic ADC driver.
442 * If 0 is passed, it disables the ADC.
443 */
444 return configure_adc(0);
445}
446#endif
447
448static SIMPLE_DEV_PM_OPS(mid_thermal_pm,
449 mid_thermal_suspend, mid_thermal_resume);
450
451/**
452 * read_curr_temp - reads the current temperature and stores in temp
453 * @temp: holds the current temperature value after reading
454 *
455 * Can sleep
456 */
457static int read_curr_temp(struct thermal_zone_device *tzd, int *temp)
458{
459 WARN_ON(tzd == NULL);
460 return mid_read_temp(tzd, temp);
461}
462
463/* Can't be const */
464static struct thermal_zone_device_ops tzd_ops = {
465 .get_temp = read_curr_temp,
466};
467
468/**
469 * mid_thermal_probe - mfld thermal initialize
470 * @pdev: platform device structure
471 *
472 * mid thermal probe initializes the hardware and registers
473 * all the sensors with the generic thermal framework. Can sleep.
474 */
475static int mid_thermal_probe(struct platform_device *pdev)
476{
477 static char *name[MSIC_THERMAL_SENSORS] = {
478 "skin0", "skin1", "sys", "msicdie"
479 };
480
481 int ret;
482 int i;
483 struct platform_info *pinfo;
484
485 pinfo = devm_kzalloc(&pdev->dev, sizeof(struct platform_info),
486 GFP_KERNEL);
487 if (!pinfo)
488 return -ENOMEM;
489
490 /* Initializing the hardware */
491 ret = mid_initialize_adc(&pdev->dev);
492 if (ret) {
493 dev_err(&pdev->dev, "ADC init failed");
494 return ret;
495 }
496
497 /* Register each sensor with the generic thermal framework*/
498 for (i = 0; i < MSIC_THERMAL_SENSORS; i++) {
499 struct thermal_device_info *td_info = initialize_sensor(i);
500
501 if (!td_info) {
502 ret = -ENOMEM;
503 goto err;
504 }
505 pinfo->tzd[i] = thermal_zone_device_register(name[i],
506 0, 0, td_info, &tzd_ops, NULL, 0, 0);
507 if (IS_ERR(pinfo->tzd[i])) {
508 kfree(td_info);
509 ret = PTR_ERR(pinfo->tzd[i]);
510 goto err;
511 }
512 }
513
514 pinfo->pdev = pdev;
515 platform_set_drvdata(pdev, pinfo);
516 return 0;
517
518err:
519 while (--i >= 0) {
520 kfree(pinfo->tzd[i]->devdata);
521 thermal_zone_device_unregister(pinfo->tzd[i]);
522 }
523 configure_adc(0);
524 return ret;
525}
526
527/**
528 * mid_thermal_remove - mfld thermal finalize
529 * @dev: platform device structure
530 *
531 * MLFD thermal remove unregisters all the sensors from the generic
532 * thermal framework. Can sleep.
533 */
534static int mid_thermal_remove(struct platform_device *pdev)
535{
536 int i;
537 struct platform_info *pinfo = platform_get_drvdata(pdev);
538
539 for (i = 0; i < MSIC_THERMAL_SENSORS; i++) {
540 kfree(pinfo->tzd[i]->devdata);
541 thermal_zone_device_unregister(pinfo->tzd[i]);
542 }
543
544 /* Stop the ADC */
545 return configure_adc(0);
546}
547
548#define DRIVER_NAME "msic_thermal"
549
550static const struct platform_device_id therm_id_table[] = {
551 { DRIVER_NAME, 1 },
552 { }
553};
554MODULE_DEVICE_TABLE(platform, therm_id_table);
555
556static struct platform_driver mid_thermal_driver = {
557 .driver = {
558 .name = DRIVER_NAME,
559 .pm = &mid_thermal_pm,
560 },
561 .probe = mid_thermal_probe,
562 .remove = mid_thermal_remove,
563 .id_table = therm_id_table,
564};
565
566module_platform_driver(mid_thermal_driver);
567
568MODULE_AUTHOR("Durgadoss R <durgadoss.r@intel.com>");
569MODULE_DESCRIPTION("Intel Medfield Platform Thermal Driver");
570MODULE_LICENSE("GPL");