1 /*
2  * intel_quark_dts_thermal.c
3  *
4  * This file is provided under a dual BSD/GPLv2 license.  When using or
5  * redistributing this file, you may do so under either license.
6  *
7  * GPL LICENSE SUMMARY
8  *
9  * Copyright(c) 2015 Intel Corporation.
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of version 2 of the GNU General Public License as
13  * published by the Free Software Foundation.
14  *
15  * This program is distributed in the hope that it will be useful, but
16  *  WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18  * General Public License for more details.
19  *
20  * Contact Information:
21  *  Ong Boon Leong <boon.leong.ong@intel.com>
22  *  Intel Malaysia, Penang
23  *
24  * BSD LICENSE
25  *
26  * Copyright(c) 2015 Intel Corporation.
27  *
28  * Redistribution and use in source and binary forms, with or without
29  * modification, are permitted provided that the following conditions
30  * are met:
31  *
32  *   * Redistributions of source code must retain the above copyright
33  *     notice, this list of conditions and the following disclaimer.
34  *   * Redistributions in binary form must reproduce the above copyright
35  *     notice, this list of conditions and the following disclaimer in
36  *     the documentation and/or other materials provided with the
37  *     distribution.
38  *   * Neither the name of Intel Corporation nor the names of its
39  *     contributors may be used to endorse or promote products derived
40  *     from this software without specific prior written permission.
41  *
42  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
43  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
44  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
45  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
46  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
47  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
48  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
49  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
50  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
51  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
52  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
53  *
54  * Quark DTS thermal driver is implemented by referencing
55  * intel_soc_dts_thermal.c.
56  */
57 
58 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
59 
60 #include <linux/module.h>
61 #include <linux/slab.h>
62 #include <linux/interrupt.h>
63 #include <linux/thermal.h>
64 #include <asm/cpu_device_id.h>
65 #include <asm/iosf_mbi.h>
66 
67 /* DTS reset is programmed via QRK_MBI_UNIT_SOC */
68 #define QRK_DTS_REG_OFFSET_RESET	0x34
69 #define QRK_DTS_RESET_BIT		BIT(0)
70 
71 /* DTS enable is programmed via QRK_MBI_UNIT_RMU */
72 #define QRK_DTS_REG_OFFSET_ENABLE	0xB0
73 #define QRK_DTS_ENABLE_BIT		BIT(15)
74 
75 /* Temperature Register is read via QRK_MBI_UNIT_RMU */
76 #define QRK_DTS_REG_OFFSET_TEMP		0xB1
77 #define QRK_DTS_MASK_TEMP		0xFF
78 #define QRK_DTS_OFFSET_TEMP		0
79 #define QRK_DTS_OFFSET_REL_TEMP		16
80 #define QRK_DTS_TEMP_BASE		50
81 
82 /* Programmable Trip Point Register is configured via QRK_MBI_UNIT_RMU */
83 #define QRK_DTS_REG_OFFSET_PTPS		0xB2
84 #define QRK_DTS_MASK_TP_THRES		0xFF
85 #define QRK_DTS_SHIFT_TP		8
86 #define QRK_DTS_ID_TP_CRITICAL		0
87 #define QRK_DTS_SAFE_TP_THRES		105
88 
89 /* Thermal Sensor Register Lock */
90 #define QRK_DTS_REG_OFFSET_LOCK		0x71
91 #define QRK_DTS_LOCK_BIT		BIT(5)
92 
93 /* Quark DTS has 2 trip points: hot & catastrophic */
94 #define QRK_MAX_DTS_TRIPS	2
95 /* If DTS not locked, all trip points are configurable */
96 #define QRK_DTS_WR_MASK_SET	0x3
97 /* If DTS locked, all trip points are not configurable */
98 #define QRK_DTS_WR_MASK_CLR	0
99 
100 #define DEFAULT_POLL_DELAY	2000
101 
102 struct soc_sensor_entry {
103 	bool locked;
104 	u32 store_ptps;
105 	u32 store_dts_enable;
106 	struct thermal_zone_device *tzone;
107 };
108 
109 static struct soc_sensor_entry *soc_dts;
110 
111 static int polling_delay = DEFAULT_POLL_DELAY;
112 module_param(polling_delay, int, 0644);
113 MODULE_PARM_DESC(polling_delay,
114 	"Polling interval for checking trip points (in milliseconds)");
115 
116 static DEFINE_MUTEX(dts_update_mutex);
117 
soc_dts_enable(struct thermal_zone_device * tzd)118 static int soc_dts_enable(struct thermal_zone_device *tzd)
119 {
120 	u32 out;
121 	struct soc_sensor_entry *aux_entry = tzd->devdata;
122 	int ret;
123 
124 	ret = iosf_mbi_read(QRK_MBI_UNIT_RMU, MBI_REG_READ,
125 			    QRK_DTS_REG_OFFSET_ENABLE, &out);
126 	if (ret)
127 		return ret;
128 
129 	if (out & QRK_DTS_ENABLE_BIT)
130 		return 0;
131 
132 	if (!aux_entry->locked) {
133 		out |= QRK_DTS_ENABLE_BIT;
134 		ret = iosf_mbi_write(QRK_MBI_UNIT_RMU, MBI_REG_WRITE,
135 				     QRK_DTS_REG_OFFSET_ENABLE, out);
136 		if (ret)
137 			return ret;
138 	} else {
139 		pr_info("DTS is locked. Cannot enable DTS\n");
140 		ret = -EPERM;
141 	}
142 
143 	return ret;
144 }
145 
soc_dts_disable(struct thermal_zone_device * tzd)146 static int soc_dts_disable(struct thermal_zone_device *tzd)
147 {
148 	u32 out;
149 	struct soc_sensor_entry *aux_entry = tzd->devdata;
150 	int ret;
151 
152 	ret = iosf_mbi_read(QRK_MBI_UNIT_RMU, MBI_REG_READ,
153 			    QRK_DTS_REG_OFFSET_ENABLE, &out);
154 	if (ret)
155 		return ret;
156 
157 	if (!(out & QRK_DTS_ENABLE_BIT))
158 		return 0;
159 
160 	if (!aux_entry->locked) {
161 		out &= ~QRK_DTS_ENABLE_BIT;
162 		ret = iosf_mbi_write(QRK_MBI_UNIT_RMU, MBI_REG_WRITE,
163 				     QRK_DTS_REG_OFFSET_ENABLE, out);
164 
165 		if (ret)
166 			return ret;
167 	} else {
168 		pr_info("DTS is locked. Cannot disable DTS\n");
169 		ret = -EPERM;
170 	}
171 
172 	return ret;
173 }
174 
_get_trip_temp(int trip,int * temp)175 static int _get_trip_temp(int trip, int *temp)
176 {
177 	int status;
178 	u32 out;
179 
180 	mutex_lock(&dts_update_mutex);
181 	status = iosf_mbi_read(QRK_MBI_UNIT_RMU, MBI_REG_READ,
182 			       QRK_DTS_REG_OFFSET_PTPS, &out);
183 	mutex_unlock(&dts_update_mutex);
184 
185 	if (status)
186 		return status;
187 
188 	/*
189 	 * Thermal Sensor Programmable Trip Point Register has 8-bit
190 	 * fields for critical (catastrophic) and hot set trip point
191 	 * thresholds. The threshold value is always offset by its
192 	 * temperature base (50 degree Celsius).
193 	 */
194 	*temp = (out >> (trip * QRK_DTS_SHIFT_TP)) & QRK_DTS_MASK_TP_THRES;
195 	*temp -= QRK_DTS_TEMP_BASE;
196 
197 	return 0;
198 }
199 
sys_get_trip_temp(struct thermal_zone_device * tzd,int trip,int * temp)200 static inline int sys_get_trip_temp(struct thermal_zone_device *tzd,
201 				int trip, int *temp)
202 {
203 	return _get_trip_temp(trip, temp);
204 }
205 
sys_get_crit_temp(struct thermal_zone_device * tzd,int * temp)206 static inline int sys_get_crit_temp(struct thermal_zone_device *tzd, int *temp)
207 {
208 	return _get_trip_temp(QRK_DTS_ID_TP_CRITICAL, temp);
209 }
210 
update_trip_temp(struct soc_sensor_entry * aux_entry,int trip,int temp)211 static int update_trip_temp(struct soc_sensor_entry *aux_entry,
212 				int trip, int temp)
213 {
214 	u32 out;
215 	u32 temp_out;
216 	u32 store_ptps;
217 	int ret;
218 
219 	mutex_lock(&dts_update_mutex);
220 	if (aux_entry->locked) {
221 		ret = -EPERM;
222 		goto failed;
223 	}
224 
225 	ret = iosf_mbi_read(QRK_MBI_UNIT_RMU, MBI_REG_READ,
226 			    QRK_DTS_REG_OFFSET_PTPS, &store_ptps);
227 	if (ret)
228 		goto failed;
229 
230 	/*
231 	 * Protection against unsafe trip point thresdhold value.
232 	 * As Quark X1000 data-sheet does not provide any recommendation
233 	 * regarding the safe trip point threshold value to use, we choose
234 	 * the safe value according to the threshold value set by UEFI BIOS.
235 	 */
236 	if (temp > QRK_DTS_SAFE_TP_THRES)
237 		temp = QRK_DTS_SAFE_TP_THRES;
238 
239 	/*
240 	 * Thermal Sensor Programmable Trip Point Register has 8-bit
241 	 * fields for critical (catastrophic) and hot set trip point
242 	 * thresholds. The threshold value is always offset by its
243 	 * temperature base (50 degree Celsius).
244 	 */
245 	temp_out = temp + QRK_DTS_TEMP_BASE;
246 	out = (store_ptps & ~(QRK_DTS_MASK_TP_THRES <<
247 		(trip * QRK_DTS_SHIFT_TP)));
248 	out |= (temp_out & QRK_DTS_MASK_TP_THRES) <<
249 		(trip * QRK_DTS_SHIFT_TP);
250 
251 	ret = iosf_mbi_write(QRK_MBI_UNIT_RMU, MBI_REG_WRITE,
252 			     QRK_DTS_REG_OFFSET_PTPS, out);
253 
254 failed:
255 	mutex_unlock(&dts_update_mutex);
256 	return ret;
257 }
258 
sys_set_trip_temp(struct thermal_zone_device * tzd,int trip,int temp)259 static inline int sys_set_trip_temp(struct thermal_zone_device *tzd, int trip,
260 				int temp)
261 {
262 	return update_trip_temp(tzd->devdata, trip, temp);
263 }
264 
sys_get_trip_type(struct thermal_zone_device * thermal,int trip,enum thermal_trip_type * type)265 static int sys_get_trip_type(struct thermal_zone_device *thermal,
266 		int trip, enum thermal_trip_type *type)
267 {
268 	if (trip)
269 		*type = THERMAL_TRIP_HOT;
270 	else
271 		*type = THERMAL_TRIP_CRITICAL;
272 
273 	return 0;
274 }
275 
sys_get_curr_temp(struct thermal_zone_device * tzd,int * temp)276 static int sys_get_curr_temp(struct thermal_zone_device *tzd,
277 				int *temp)
278 {
279 	u32 out;
280 	int ret;
281 
282 	mutex_lock(&dts_update_mutex);
283 	ret = iosf_mbi_read(QRK_MBI_UNIT_RMU, MBI_REG_READ,
284 			    QRK_DTS_REG_OFFSET_TEMP, &out);
285 	mutex_unlock(&dts_update_mutex);
286 
287 	if (ret)
288 		return ret;
289 
290 	/*
291 	 * Thermal Sensor Temperature Register has 8-bit field
292 	 * for temperature value (offset by temperature base
293 	 * 50 degree Celsius).
294 	 */
295 	out = (out >> QRK_DTS_OFFSET_TEMP) & QRK_DTS_MASK_TEMP;
296 	*temp = out - QRK_DTS_TEMP_BASE;
297 
298 	return 0;
299 }
300 
sys_change_mode(struct thermal_zone_device * tzd,enum thermal_device_mode mode)301 static int sys_change_mode(struct thermal_zone_device *tzd,
302 			   enum thermal_device_mode mode)
303 {
304 	int ret;
305 
306 	mutex_lock(&dts_update_mutex);
307 	if (mode == THERMAL_DEVICE_ENABLED)
308 		ret = soc_dts_enable(tzd);
309 	else
310 		ret = soc_dts_disable(tzd);
311 	mutex_unlock(&dts_update_mutex);
312 
313 	return ret;
314 }
315 
316 static struct thermal_zone_device_ops tzone_ops = {
317 	.get_temp = sys_get_curr_temp,
318 	.get_trip_temp = sys_get_trip_temp,
319 	.get_trip_type = sys_get_trip_type,
320 	.set_trip_temp = sys_set_trip_temp,
321 	.get_crit_temp = sys_get_crit_temp,
322 	.change_mode = sys_change_mode,
323 };
324 
free_soc_dts(struct soc_sensor_entry * aux_entry)325 static void free_soc_dts(struct soc_sensor_entry *aux_entry)
326 {
327 	if (aux_entry) {
328 		if (!aux_entry->locked) {
329 			mutex_lock(&dts_update_mutex);
330 			iosf_mbi_write(QRK_MBI_UNIT_RMU, MBI_REG_WRITE,
331 				       QRK_DTS_REG_OFFSET_ENABLE,
332 				       aux_entry->store_dts_enable);
333 
334 			iosf_mbi_write(QRK_MBI_UNIT_RMU, MBI_REG_WRITE,
335 				       QRK_DTS_REG_OFFSET_PTPS,
336 				       aux_entry->store_ptps);
337 			mutex_unlock(&dts_update_mutex);
338 		}
339 		thermal_zone_device_unregister(aux_entry->tzone);
340 		kfree(aux_entry);
341 	}
342 }
343 
alloc_soc_dts(void)344 static struct soc_sensor_entry *alloc_soc_dts(void)
345 {
346 	struct soc_sensor_entry *aux_entry;
347 	int err;
348 	u32 out;
349 	int wr_mask;
350 
351 	aux_entry = kzalloc(sizeof(*aux_entry), GFP_KERNEL);
352 	if (!aux_entry) {
353 		err = -ENOMEM;
354 		return ERR_PTR(-ENOMEM);
355 	}
356 
357 	/* Check if DTS register is locked */
358 	err = iosf_mbi_read(QRK_MBI_UNIT_RMU, MBI_REG_READ,
359 			    QRK_DTS_REG_OFFSET_LOCK, &out);
360 	if (err)
361 		goto err_ret;
362 
363 	if (out & QRK_DTS_LOCK_BIT) {
364 		aux_entry->locked = true;
365 		wr_mask = QRK_DTS_WR_MASK_CLR;
366 	} else {
367 		aux_entry->locked = false;
368 		wr_mask = QRK_DTS_WR_MASK_SET;
369 	}
370 
371 	/* Store DTS default state if DTS registers are not locked */
372 	if (!aux_entry->locked) {
373 		/* Store DTS default enable for restore on exit */
374 		err = iosf_mbi_read(QRK_MBI_UNIT_RMU, MBI_REG_READ,
375 				    QRK_DTS_REG_OFFSET_ENABLE,
376 				    &aux_entry->store_dts_enable);
377 		if (err)
378 			goto err_ret;
379 
380 		/* Store DTS default PTPS register for restore on exit */
381 		err = iosf_mbi_read(QRK_MBI_UNIT_RMU, MBI_REG_READ,
382 				    QRK_DTS_REG_OFFSET_PTPS,
383 				    &aux_entry->store_ptps);
384 		if (err)
385 			goto err_ret;
386 	}
387 
388 	aux_entry->tzone = thermal_zone_device_register("quark_dts",
389 			QRK_MAX_DTS_TRIPS,
390 			wr_mask,
391 			aux_entry, &tzone_ops, NULL, 0, polling_delay);
392 	if (IS_ERR(aux_entry->tzone)) {
393 		err = PTR_ERR(aux_entry->tzone);
394 		goto err_ret;
395 	}
396 
397 	err = thermal_zone_device_enable(aux_entry->tzone);
398 	if (err)
399 		goto err_aux_status;
400 
401 	return aux_entry;
402 
403 err_aux_status:
404 	thermal_zone_device_unregister(aux_entry->tzone);
405 err_ret:
406 	kfree(aux_entry);
407 	return ERR_PTR(err);
408 }
409 
410 static const struct x86_cpu_id qrk_thermal_ids[] __initconst  = {
411 	X86_MATCH_VENDOR_FAM_MODEL(INTEL, 5, INTEL_FAM5_QUARK_X1000, NULL),
412 	{}
413 };
414 MODULE_DEVICE_TABLE(x86cpu, qrk_thermal_ids);
415 
intel_quark_thermal_init(void)416 static int __init intel_quark_thermal_init(void)
417 {
418 	int err = 0;
419 
420 	if (!x86_match_cpu(qrk_thermal_ids) || !iosf_mbi_available())
421 		return -ENODEV;
422 
423 	soc_dts = alloc_soc_dts();
424 	if (IS_ERR(soc_dts)) {
425 		err = PTR_ERR(soc_dts);
426 		goto err_free;
427 	}
428 
429 	return 0;
430 
431 err_free:
432 	free_soc_dts(soc_dts);
433 	return err;
434 }
435 
intel_quark_thermal_exit(void)436 static void __exit intel_quark_thermal_exit(void)
437 {
438 	free_soc_dts(soc_dts);
439 }
440 
441 module_init(intel_quark_thermal_init)
442 module_exit(intel_quark_thermal_exit)
443 
444 MODULE_DESCRIPTION("Intel Quark DTS Thermal Driver");
445 MODULE_AUTHOR("Ong Boon Leong <boon.leong.ong@intel.com>");
446 MODULE_LICENSE("Dual BSD/GPL");
447