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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// SPDX-License-Identifier: GPL-2.0
2/*
3 * Intel MID platform thermal driver
4 *
5 * Copyright (C) 2011 Intel Corporation
6 *
7 * Author: Durgadoss R <durgadoss.r@intel.com>
8 */
9
10#define pr_fmt(fmt) "intel_mid_thermal: " fmt
11
12#include <linux/device.h>
13#include <linux/err.h>
14#include <linux/mfd/intel_msic.h>
15#include <linux/module.h>
16#include <linux/param.h>
17#include <linux/platform_device.h>
18#include <linux/pm.h>
19#include <linux/slab.h>
20#include <linux/thermal.h>
21
22/* Number of thermal sensors */
23#define MSIC_THERMAL_SENSORS 4
24
25/* ADC1 - thermal registers */
26#define MSIC_ADC_ENBL 0x10
27#define MSIC_ADC_START 0x08
28
29#define MSIC_ADCTHERM_ENBL 0x04
30#define MSIC_ADCRRDATA_ENBL 0x05
31#define MSIC_CHANL_MASK_VAL 0x0F
32
33#define MSIC_STOPBIT_MASK 16
34#define MSIC_ADCTHERM_MASK 4
35/* Number of ADC channels */
36#define ADC_CHANLS_MAX 15
37#define ADC_LOOP_MAX (ADC_CHANLS_MAX - MSIC_THERMAL_SENSORS)
38
39/* ADC channel code values */
40#define SKIN_SENSOR0_CODE 0x08
41#define SKIN_SENSOR1_CODE 0x09
42#define SYS_SENSOR_CODE 0x0A
43#define MSIC_DIE_SENSOR_CODE 0x03
44
45#define SKIN_THERM_SENSOR0 0
46#define SKIN_THERM_SENSOR1 1
47#define SYS_THERM_SENSOR2 2
48#define MSIC_DIE_THERM_SENSOR3 3
49
50/* ADC code range */
51#define ADC_MAX 977
52#define ADC_MIN 162
53#define ADC_VAL0C 887
54#define ADC_VAL20C 720
55#define ADC_VAL40C 508
56#define ADC_VAL60C 315
57
58/* ADC base addresses */
59#define ADC_CHNL_START_ADDR INTEL_MSIC_ADC1ADDR0 /* increments by 1 */
60#define ADC_DATA_START_ADDR INTEL_MSIC_ADC1SNS0H /* increments by 2 */
61
62/* MSIC die attributes */
63#define MSIC_DIE_ADC_MIN 488
64#define MSIC_DIE_ADC_MAX 1004
65
66/* This holds the address of the first free ADC channel,
67 * among the 15 channels
68 */
69static int channel_index;
70
71struct platform_info {
72 struct platform_device *pdev;
73 struct thermal_zone_device *tzd[MSIC_THERMAL_SENSORS];
74};
75
76struct thermal_device_info {
77 unsigned int chnl_addr;
78 int direct;
79 /* This holds the current temperature in millidegree celsius */
80 long curr_temp;
81};
82
83/**
84 * to_msic_die_temp - converts adc_val to msic_die temperature
85 * @adc_val: ADC value to be converted
86 *
87 * Can sleep
88 */
89static int to_msic_die_temp(uint16_t adc_val)
90{
91 return (368 * (adc_val) / 1000) - 220;
92}
93
94/**
95 * is_valid_adc - checks whether the adc code is within the defined range
96 * @min: minimum value for the sensor
97 * @max: maximum value for the sensor
98 *
99 * Can sleep
100 */
101static int is_valid_adc(uint16_t adc_val, uint16_t min, uint16_t max)
102{
103 return (adc_val >= min) && (adc_val <= max);
104}
105
106/**
107 * adc_to_temp - converts the ADC code to temperature in C
108 * @direct: true if ths channel is direct index
109 * @adc_val: the adc_val that needs to be converted
110 * @tp: temperature return value
111 *
112 * Linear approximation is used to covert the skin adc value into temperature.
113 * This technique is used to avoid very long look-up table to get
114 * the appropriate temp value from ADC value.
115 * The adc code vs sensor temp curve is split into five parts
116 * to achieve very close approximate temp value with less than
117 * 0.5C error
118 */
119static int adc_to_temp(int direct, uint16_t adc_val, int *tp)
120{
121 int temp;
122
123 /* Direct conversion for die temperature */
124 if (direct) {
125 if (is_valid_adc(adc_val, MSIC_DIE_ADC_MIN, MSIC_DIE_ADC_MAX)) {
126 *tp = to_msic_die_temp(adc_val) * 1000;
127 return 0;
128 }
129 return -ERANGE;
130 }
131
132 if (!is_valid_adc(adc_val, ADC_MIN, ADC_MAX))
133 return -ERANGE;
134
135 /* Linear approximation for skin temperature */
136 if (adc_val > ADC_VAL0C)
137 temp = 177 - (adc_val/5);
138 else if ((adc_val <= ADC_VAL0C) && (adc_val > ADC_VAL20C))
139 temp = 111 - (adc_val/8);
140 else if ((adc_val <= ADC_VAL20C) && (adc_val > ADC_VAL40C))
141 temp = 92 - (adc_val/10);
142 else if ((adc_val <= ADC_VAL40C) && (adc_val > ADC_VAL60C))
143 temp = 91 - (adc_val/10);
144 else
145 temp = 112 - (adc_val/6);
146
147 /* Convert temperature in celsius to milli degree celsius */
148 *tp = temp * 1000;
149 return 0;
150}
151
152/**
153 * mid_read_temp - read sensors for temperature
154 * @temp: holds the current temperature for the sensor after reading
155 *
156 * reads the adc_code from the channel and converts it to real
157 * temperature. The converted value is stored in temp.
158 *
159 * Can sleep
160 */
161static int mid_read_temp(struct thermal_zone_device *tzd, int *temp)
162{
163 struct thermal_device_info *td_info = tzd->devdata;
164 uint16_t adc_val, addr;
165 uint8_t data = 0;
166 int ret;
167 int curr_temp;
168
169 addr = td_info->chnl_addr;
170
171 /* Enable the msic for conversion before reading */
172 ret = intel_msic_reg_write(INTEL_MSIC_ADC1CNTL3, MSIC_ADCRRDATA_ENBL);
173 if (ret)
174 return ret;
175
176 /* Re-toggle the RRDATARD bit (temporary workaround) */
177 ret = intel_msic_reg_write(INTEL_MSIC_ADC1CNTL3, MSIC_ADCTHERM_ENBL);
178 if (ret)
179 return ret;
180
181 /* Read the higher bits of data */
182 ret = intel_msic_reg_read(addr, &data);
183 if (ret)
184 return ret;
185
186 /* Shift bits to accommodate the lower two data bits */
187 adc_val = (data << 2);
188 addr++;
189
190 ret = intel_msic_reg_read(addr, &data);/* Read lower bits */
191 if (ret)
192 return ret;
193
194 /* Adding lower two bits to the higher bits */
195 data &= 03;
196 adc_val += data;
197
198 /* Convert ADC value to temperature */
199 ret = adc_to_temp(td_info->direct, adc_val, &curr_temp);
200 if (ret == 0)
201 *temp = td_info->curr_temp = curr_temp;
202 return ret;
203}
204
205/**
206 * configure_adc - enables/disables the ADC for conversion
207 * @val: zero: disables the ADC non-zero:enables the ADC
208 *
209 * Enable/Disable the ADC depending on the argument
210 *
211 * Can sleep
212 */
213static int configure_adc(int val)
214{
215 int ret;
216 uint8_t data;
217
218 ret = intel_msic_reg_read(INTEL_MSIC_ADC1CNTL1, &data);
219 if (ret)
220 return ret;
221
222 if (val) {
223 /* Enable and start the ADC */
224 data |= (MSIC_ADC_ENBL | MSIC_ADC_START);
225 } else {
226 /* Just stop the ADC */
227 data &= (~MSIC_ADC_START);
228 }
229 return intel_msic_reg_write(INTEL_MSIC_ADC1CNTL1, data);
230}
231
232/**
233 * set_up_therm_channel - enable thermal channel for conversion
234 * @base_addr: index of free msic ADC channel
235 *
236 * Enable all the three channels for conversion
237 *
238 * Can sleep
239 */
240static int set_up_therm_channel(u16 base_addr)
241{
242 int ret;
243
244 /* Enable all the sensor channels */
245 ret = intel_msic_reg_write(base_addr, SKIN_SENSOR0_CODE);
246 if (ret)
247 return ret;
248
249 ret = intel_msic_reg_write(base_addr + 1, SKIN_SENSOR1_CODE);
250 if (ret)
251 return ret;
252
253 ret = intel_msic_reg_write(base_addr + 2, SYS_SENSOR_CODE);
254 if (ret)
255 return ret;
256
257 /* Since this is the last channel, set the stop bit
258 * to 1 by ORing the DIE_SENSOR_CODE with 0x10 */
259 ret = intel_msic_reg_write(base_addr + 3,
260 (MSIC_DIE_SENSOR_CODE | 0x10));
261 if (ret)
262 return ret;
263
264 /* Enable ADC and start it */
265 return configure_adc(1);
266}
267
268/**
269 * reset_stopbit - sets the stop bit to 0 on the given channel
270 * @addr: address of the channel
271 *
272 * Can sleep
273 */
274static int reset_stopbit(uint16_t addr)
275{
276 int ret;
277 uint8_t data;
278 ret = intel_msic_reg_read(addr, &data);
279 if (ret)
280 return ret;
281 /* Set the stop bit to zero */
282 return intel_msic_reg_write(addr, (data & 0xEF));
283}
284
285/**
286 * find_free_channel - finds an empty channel for conversion
287 *
288 * If the ADC is not enabled then start using 0th channel
289 * itself. Otherwise find an empty channel by looking for a
290 * channel in which the stopbit is set to 1. returns the index
291 * of the first free channel if succeeds or an error code.
292 *
293 * Context: can sleep
294 *
295 * FIXME: Ultimately the channel allocator will move into the intel_scu_ipc
296 * code.
297 */
298static int find_free_channel(void)
299{
300 int ret;
301 int i;
302 uint8_t data;
303
304 /* check whether ADC is enabled */
305 ret = intel_msic_reg_read(INTEL_MSIC_ADC1CNTL1, &data);
306 if (ret)
307 return ret;
308
309 if ((data & MSIC_ADC_ENBL) == 0)
310 return 0;
311
312 /* ADC is already enabled; Looking for an empty channel */
313 for (i = 0; i < ADC_CHANLS_MAX; i++) {
314 ret = intel_msic_reg_read(ADC_CHNL_START_ADDR + i, &data);
315 if (ret)
316 return ret;
317
318 if (data & MSIC_STOPBIT_MASK) {
319 ret = i;
320 break;
321 }
322 }
323 return (ret > ADC_LOOP_MAX) ? (-EINVAL) : ret;
324}
325
326/**
327 * mid_initialize_adc - initializing the ADC
328 * @dev: our device structure
329 *
330 * Initialize the ADC for reading thermistor values. Can sleep.
331 */
332static int mid_initialize_adc(struct device *dev)
333{
334 u8 data;
335 u16 base_addr;
336 int ret;
337
338 /*
339 * Ensure that adctherm is disabled before we
340 * initialize the ADC
341 */
342 ret = intel_msic_reg_read(INTEL_MSIC_ADC1CNTL3, &data);
343 if (ret)
344 return ret;
345
346 data &= ~MSIC_ADCTHERM_MASK;
347 ret = intel_msic_reg_write(INTEL_MSIC_ADC1CNTL3, data);
348 if (ret)
349 return ret;
350
351 /* Index of the first channel in which the stop bit is set */
352 channel_index = find_free_channel();
353 if (channel_index < 0) {
354 dev_err(dev, "No free ADC channels");
355 return channel_index;
356 }
357
358 base_addr = ADC_CHNL_START_ADDR + channel_index;
359
360 if (!(channel_index == 0 || channel_index == ADC_LOOP_MAX)) {
361 /* Reset stop bit for channels other than 0 and 12 */
362 ret = reset_stopbit(base_addr);
363 if (ret)
364 return ret;
365
366 /* Index of the first free channel */
367 base_addr++;
368 channel_index++;
369 }
370
371 ret = set_up_therm_channel(base_addr);
372 if (ret) {
373 dev_err(dev, "unable to enable ADC");
374 return ret;
375 }
376 dev_dbg(dev, "ADC initialization successful");
377 return ret;
378}
379
380/**
381 * initialize_sensor - sets default temp and timer ranges
382 * @index: index of the sensor
383 *
384 * Context: can sleep
385 */
386static struct thermal_device_info *initialize_sensor(int index)
387{
388 struct thermal_device_info *td_info =
389 kzalloc(sizeof(struct thermal_device_info), GFP_KERNEL);
390
391 if (!td_info)
392 return NULL;
393
394 /* Set the base addr of the channel for this sensor */
395 td_info->chnl_addr = ADC_DATA_START_ADDR + 2 * (channel_index + index);
396 /* Sensor 3 is direct conversion */
397 if (index == 3)
398 td_info->direct = 1;
399 return td_info;
400}
401
402#ifdef CONFIG_PM_SLEEP
403/**
404 * mid_thermal_resume - resume routine
405 * @dev: device structure
406 *
407 * mid thermal resume: re-initializes the adc. Can sleep.
408 */
409static int mid_thermal_resume(struct device *dev)
410{
411 return mid_initialize_adc(dev);
412}
413
414/**
415 * mid_thermal_suspend - suspend routine
416 * @dev: device structure
417 *
418 * mid thermal suspend implements the suspend functionality
419 * by stopping the ADC. Can sleep.
420 */
421static int mid_thermal_suspend(struct device *dev)
422{
423 /*
424 * This just stops the ADC and does not disable it.
425 * temporary workaround until we have a generic ADC driver.
426 * If 0 is passed, it disables the ADC.
427 */
428 return configure_adc(0);
429}
430#endif
431
432static SIMPLE_DEV_PM_OPS(mid_thermal_pm,
433 mid_thermal_suspend, mid_thermal_resume);
434
435/**
436 * read_curr_temp - reads the current temperature and stores in temp
437 * @temp: holds the current temperature value after reading
438 *
439 * Can sleep
440 */
441static int read_curr_temp(struct thermal_zone_device *tzd, int *temp)
442{
443 WARN_ON(tzd == NULL);
444 return mid_read_temp(tzd, temp);
445}
446
447/* Can't be const */
448static struct thermal_zone_device_ops tzd_ops = {
449 .get_temp = read_curr_temp,
450};
451
452/**
453 * mid_thermal_probe - mfld thermal initialize
454 * @pdev: platform device structure
455 *
456 * mid thermal probe initializes the hardware and registers
457 * all the sensors with the generic thermal framework. Can sleep.
458 */
459static int mid_thermal_probe(struct platform_device *pdev)
460{
461 static char *name[MSIC_THERMAL_SENSORS] = {
462 "skin0", "skin1", "sys", "msicdie"
463 };
464
465 int ret;
466 int i;
467 struct platform_info *pinfo;
468
469 pinfo = devm_kzalloc(&pdev->dev, sizeof(struct platform_info),
470 GFP_KERNEL);
471 if (!pinfo)
472 return -ENOMEM;
473
474 /* Initializing the hardware */
475 ret = mid_initialize_adc(&pdev->dev);
476 if (ret) {
477 dev_err(&pdev->dev, "ADC init failed");
478 return ret;
479 }
480
481 /* Register each sensor with the generic thermal framework*/
482 for (i = 0; i < MSIC_THERMAL_SENSORS; i++) {
483 struct thermal_device_info *td_info = initialize_sensor(i);
484
485 if (!td_info) {
486 ret = -ENOMEM;
487 goto err;
488 }
489 pinfo->tzd[i] = thermal_zone_device_register(name[i],
490 0, 0, td_info, &tzd_ops, NULL, 0, 0);
491 if (IS_ERR(pinfo->tzd[i])) {
492 kfree(td_info);
493 ret = PTR_ERR(pinfo->tzd[i]);
494 goto err;
495 }
496 ret = thermal_zone_device_enable(pinfo->tzd[i]);
497 if (ret) {
498 kfree(td_info);
499 thermal_zone_device_unregister(pinfo->tzd[i]);
500 goto err;
501 }
502 }
503
504 pinfo->pdev = pdev;
505 platform_set_drvdata(pdev, pinfo);
506 return 0;
507
508err:
509 while (--i >= 0) {
510 kfree(pinfo->tzd[i]->devdata);
511 thermal_zone_device_unregister(pinfo->tzd[i]);
512 }
513 configure_adc(0);
514 return ret;
515}
516
517/**
518 * mid_thermal_remove - mfld thermal finalize
519 * @dev: platform device structure
520 *
521 * MLFD thermal remove unregisters all the sensors from the generic
522 * thermal framework. Can sleep.
523 */
524static int mid_thermal_remove(struct platform_device *pdev)
525{
526 int i;
527 struct platform_info *pinfo = platform_get_drvdata(pdev);
528
529 for (i = 0; i < MSIC_THERMAL_SENSORS; i++) {
530 kfree(pinfo->tzd[i]->devdata);
531 thermal_zone_device_unregister(pinfo->tzd[i]);
532 }
533
534 /* Stop the ADC */
535 return configure_adc(0);
536}
537
538#define DRIVER_NAME "msic_thermal"
539
540static const struct platform_device_id therm_id_table[] = {
541 { DRIVER_NAME, 1 },
542 { }
543};
544MODULE_DEVICE_TABLE(platform, therm_id_table);
545
546static struct platform_driver mid_thermal_driver = {
547 .driver = {
548 .name = DRIVER_NAME,
549 .pm = &mid_thermal_pm,
550 },
551 .probe = mid_thermal_probe,
552 .remove = mid_thermal_remove,
553 .id_table = therm_id_table,
554};
555
556module_platform_driver(mid_thermal_driver);
557
558MODULE_AUTHOR("Durgadoss R <durgadoss.r@intel.com>");
559MODULE_DESCRIPTION("Intel Medfield Platform Thermal Driver");
560MODULE_LICENSE("GPL v2");