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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#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/**
419 * mid_thermal_resume - resume routine
420 * @dev: device structure
421 *
422 * mid thermal resume: re-initializes the adc. Can sleep.
423 */
424static int mid_thermal_resume(struct device *dev)
425{
426 return mid_initialize_adc(dev);
427}
428
429/**
430 * mid_thermal_suspend - suspend routine
431 * @dev: device structure
432 *
433 * mid thermal suspend implements the suspend functionality
434 * by stopping the ADC. Can sleep.
435 */
436static int mid_thermal_suspend(struct device *dev)
437{
438 /*
439 * This just stops the ADC and does not disable it.
440 * temporary workaround until we have a generic ADC driver.
441 * If 0 is passed, it disables the ADC.
442 */
443 return configure_adc(0);
444}
445
446static SIMPLE_DEV_PM_OPS(mid_thermal_pm,
447 mid_thermal_suspend, mid_thermal_resume);
448
449/**
450 * read_curr_temp - reads the current temperature and stores in temp
451 * @temp: holds the current temperature value after reading
452 *
453 * Can sleep
454 */
455static int read_curr_temp(struct thermal_zone_device *tzd, int *temp)
456{
457 WARN_ON(tzd == NULL);
458 return mid_read_temp(tzd, temp);
459}
460
461/* Can't be const */
462static struct thermal_zone_device_ops tzd_ops = {
463 .get_temp = read_curr_temp,
464};
465
466/**
467 * mid_thermal_probe - mfld thermal initialize
468 * @pdev: platform device structure
469 *
470 * mid thermal probe initializes the hardware and registers
471 * all the sensors with the generic thermal framework. Can sleep.
472 */
473static int mid_thermal_probe(struct platform_device *pdev)
474{
475 static char *name[MSIC_THERMAL_SENSORS] = {
476 "skin0", "skin1", "sys", "msicdie"
477 };
478
479 int ret;
480 int i;
481 struct platform_info *pinfo;
482
483 pinfo = devm_kzalloc(&pdev->dev, sizeof(struct platform_info),
484 GFP_KERNEL);
485 if (!pinfo)
486 return -ENOMEM;
487
488 /* Initializing the hardware */
489 ret = mid_initialize_adc(&pdev->dev);
490 if (ret) {
491 dev_err(&pdev->dev, "ADC init failed");
492 return ret;
493 }
494
495 /* Register each sensor with the generic thermal framework*/
496 for (i = 0; i < MSIC_THERMAL_SENSORS; i++) {
497 struct thermal_device_info *td_info = initialize_sensor(i);
498
499 if (!td_info) {
500 ret = -ENOMEM;
501 goto err;
502 }
503 pinfo->tzd[i] = thermal_zone_device_register(name[i],
504 0, 0, td_info, &tzd_ops, NULL, 0, 0);
505 if (IS_ERR(pinfo->tzd[i])) {
506 kfree(td_info);
507 ret = PTR_ERR(pinfo->tzd[i]);
508 goto err;
509 }
510 }
511
512 pinfo->pdev = pdev;
513 platform_set_drvdata(pdev, pinfo);
514 return 0;
515
516err:
517 while (--i >= 0) {
518 kfree(pinfo->tzd[i]->devdata);
519 thermal_zone_device_unregister(pinfo->tzd[i]);
520 }
521 configure_adc(0);
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 /* Stop the ADC */
543 return configure_adc(0);
544}
545
546#define DRIVER_NAME "msic_thermal"
547
548static const struct platform_device_id therm_id_table[] = {
549 { DRIVER_NAME, 1 },
550 { "msic_thermal", 1 },
551 { }
552};
553
554static struct platform_driver mid_thermal_driver = {
555 .driver = {
556 .name = DRIVER_NAME,
557 .pm = &mid_thermal_pm,
558 },
559 .probe = mid_thermal_probe,
560 .remove = mid_thermal_remove,
561 .id_table = therm_id_table,
562};
563
564module_platform_driver(mid_thermal_driver);
565
566MODULE_AUTHOR("Durgadoss R <durgadoss.r@intel.com>");
567MODULE_DESCRIPTION("Intel Medfield Platform Thermal Driver");
568MODULE_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 }
497
498 pinfo->pdev = pdev;
499 platform_set_drvdata(pdev, pinfo);
500 return 0;
501
502err:
503 while (--i >= 0) {
504 kfree(pinfo->tzd[i]->devdata);
505 thermal_zone_device_unregister(pinfo->tzd[i]);
506 }
507 configure_adc(0);
508 return ret;
509}
510
511/**
512 * mid_thermal_remove - mfld thermal finalize
513 * @dev: platform device structure
514 *
515 * MLFD thermal remove unregisters all the sensors from the generic
516 * thermal framework. Can sleep.
517 */
518static int mid_thermal_remove(struct platform_device *pdev)
519{
520 int i;
521 struct platform_info *pinfo = platform_get_drvdata(pdev);
522
523 for (i = 0; i < MSIC_THERMAL_SENSORS; i++) {
524 kfree(pinfo->tzd[i]->devdata);
525 thermal_zone_device_unregister(pinfo->tzd[i]);
526 }
527
528 /* Stop the ADC */
529 return configure_adc(0);
530}
531
532#define DRIVER_NAME "msic_thermal"
533
534static const struct platform_device_id therm_id_table[] = {
535 { DRIVER_NAME, 1 },
536 { }
537};
538MODULE_DEVICE_TABLE(platform, therm_id_table);
539
540static struct platform_driver mid_thermal_driver = {
541 .driver = {
542 .name = DRIVER_NAME,
543 .pm = &mid_thermal_pm,
544 },
545 .probe = mid_thermal_probe,
546 .remove = mid_thermal_remove,
547 .id_table = therm_id_table,
548};
549
550module_platform_driver(mid_thermal_driver);
551
552MODULE_AUTHOR("Durgadoss R <durgadoss.r@intel.com>");
553MODULE_DESCRIPTION("Intel Medfield Platform Thermal Driver");
554MODULE_LICENSE("GPL v2");