1 /*
2  * Hisilicon thermal sensor driver
3  *
4  * Copyright (c) 2014-2015 Hisilicon Limited.
5  * Copyright (c) 2014-2015 Linaro Limited.
6  *
7  * Xinwei Kong <kong.kongxinwei@hisilicon.com>
8  * Leo Yan <leo.yan@linaro.org>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License version 2 as
12  * published by the Free Software Foundation.
13  *
14  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
15  * kind, whether express or implied; without even the implied warranty
16  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17  * GNU General Public License for more details.
18  */
19 
20 #include <linux/cpufreq.h>
21 #include <linux/delay.h>
22 #include <linux/interrupt.h>
23 #include <linux/module.h>
24 #include <linux/platform_device.h>
25 #include <linux/io.h>
26 
27 #include "thermal_core.h"
28 
29 #define TEMP0_TH			(0x4)
30 #define TEMP0_RST_TH			(0x8)
31 #define TEMP0_CFG			(0xC)
32 #define TEMP0_EN			(0x10)
33 #define TEMP0_INT_EN			(0x14)
34 #define TEMP0_INT_CLR			(0x18)
35 #define TEMP0_RST_MSK			(0x1C)
36 #define TEMP0_VALUE			(0x28)
37 
38 #define HISI_TEMP_BASE			(-60)
39 #define HISI_TEMP_RESET			(100000)
40 
41 #define HISI_MAX_SENSORS		4
42 
43 struct hisi_thermal_sensor {
44 	struct hisi_thermal_data *thermal;
45 	struct thermal_zone_device *tzd;
46 
47 	long sensor_temp;
48 	uint32_t id;
49 	uint32_t thres_temp;
50 };
51 
52 struct hisi_thermal_data {
53 	struct mutex thermal_lock;    /* protects register data */
54 	struct platform_device *pdev;
55 	struct clk *clk;
56 	struct hisi_thermal_sensor sensors[HISI_MAX_SENSORS];
57 
58 	int irq, irq_bind_sensor;
59 	bool irq_enabled;
60 
61 	void __iomem *regs;
62 };
63 
64 /* in millicelsius */
65 static inline int _step_to_temp(int step)
66 {
67 	/*
68 	 * Every step equals (1 * 200) / 255 celsius, and finally
69 	 * need convert to millicelsius.
70 	 */
71 	return (HISI_TEMP_BASE * 1000 + (step * 200000 / 255));
72 }
73 
74 static inline long _temp_to_step(long temp)
75 {
76 	return ((temp - HISI_TEMP_BASE * 1000) * 255) / 200000;
77 }
78 
79 static long hisi_thermal_get_sensor_temp(struct hisi_thermal_data *data,
80 					 struct hisi_thermal_sensor *sensor)
81 {
82 	long val;
83 
84 	mutex_lock(&data->thermal_lock);
85 
86 	/* disable interrupt */
87 	writel(0x0, data->regs + TEMP0_INT_EN);
88 	writel(0x1, data->regs + TEMP0_INT_CLR);
89 
90 	/* disable module firstly */
91 	writel(0x0, data->regs + TEMP0_EN);
92 
93 	/* select sensor id */
94 	writel((sensor->id << 12), data->regs + TEMP0_CFG);
95 
96 	/* enable module */
97 	writel(0x1, data->regs + TEMP0_EN);
98 
99 	usleep_range(3000, 5000);
100 
101 	val = readl(data->regs + TEMP0_VALUE);
102 	val = _step_to_temp(val);
103 
104 	mutex_unlock(&data->thermal_lock);
105 
106 	return val;
107 }
108 
109 static void hisi_thermal_enable_bind_irq_sensor
110 			(struct hisi_thermal_data *data)
111 {
112 	struct hisi_thermal_sensor *sensor;
113 
114 	mutex_lock(&data->thermal_lock);
115 
116 	sensor = &data->sensors[data->irq_bind_sensor];
117 
118 	/* setting the hdak time */
119 	writel(0x0, data->regs + TEMP0_CFG);
120 
121 	/* disable module firstly */
122 	writel(0x0, data->regs + TEMP0_RST_MSK);
123 	writel(0x0, data->regs + TEMP0_EN);
124 
125 	/* select sensor id */
126 	writel((sensor->id << 12), data->regs + TEMP0_CFG);
127 
128 	/* enable for interrupt */
129 	writel(_temp_to_step(sensor->thres_temp) | 0x0FFFFFF00,
130 	       data->regs + TEMP0_TH);
131 
132 	writel(_temp_to_step(HISI_TEMP_RESET), data->regs + TEMP0_RST_TH);
133 
134 	/* enable module */
135 	writel(0x1, data->regs + TEMP0_RST_MSK);
136 	writel(0x1, data->regs + TEMP0_EN);
137 
138 	writel(0x0, data->regs + TEMP0_INT_CLR);
139 	writel(0x1, data->regs + TEMP0_INT_EN);
140 
141 	usleep_range(3000, 5000);
142 
143 	mutex_unlock(&data->thermal_lock);
144 }
145 
146 static void hisi_thermal_disable_sensor(struct hisi_thermal_data *data)
147 {
148 	mutex_lock(&data->thermal_lock);
149 
150 	/* disable sensor module */
151 	writel(0x0, data->regs + TEMP0_INT_EN);
152 	writel(0x0, data->regs + TEMP0_RST_MSK);
153 	writel(0x0, data->regs + TEMP0_EN);
154 
155 	mutex_unlock(&data->thermal_lock);
156 }
157 
158 static int hisi_thermal_get_temp(void *_sensor, int *temp)
159 {
160 	struct hisi_thermal_sensor *sensor = _sensor;
161 	struct hisi_thermal_data *data = sensor->thermal;
162 
163 	int sensor_id = -1, i;
164 	long max_temp = 0;
165 
166 	*temp = hisi_thermal_get_sensor_temp(data, sensor);
167 
168 	sensor->sensor_temp = *temp;
169 
170 	for (i = 0; i < HISI_MAX_SENSORS; i++) {
171 		if (!data->sensors[i].tzd)
172 			continue;
173 
174 		if (data->sensors[i].sensor_temp >= max_temp) {
175 			max_temp = data->sensors[i].sensor_temp;
176 			sensor_id = i;
177 		}
178 	}
179 
180 	/* If no sensor has been enabled, then skip to enable irq */
181 	if (sensor_id == -1)
182 		return 0;
183 
184 	mutex_lock(&data->thermal_lock);
185 	data->irq_bind_sensor = sensor_id;
186 	mutex_unlock(&data->thermal_lock);
187 
188 	dev_dbg(&data->pdev->dev, "id=%d, irq=%d, temp=%d, thres=%d\n",
189 		sensor->id, data->irq_enabled, *temp, sensor->thres_temp);
190 	/*
191 	 * Bind irq to sensor for two cases:
192 	 *   Reenable alarm IRQ if temperature below threshold;
193 	 *   if irq has been enabled, always set it;
194 	 */
195 	if (data->irq_enabled) {
196 		hisi_thermal_enable_bind_irq_sensor(data);
197 		return 0;
198 	}
199 
200 	if (max_temp < sensor->thres_temp) {
201 		data->irq_enabled = true;
202 		hisi_thermal_enable_bind_irq_sensor(data);
203 		enable_irq(data->irq);
204 	}
205 
206 	return 0;
207 }
208 
209 static struct thermal_zone_of_device_ops hisi_of_thermal_ops = {
210 	.get_temp = hisi_thermal_get_temp,
211 };
212 
213 static irqreturn_t hisi_thermal_alarm_irq(int irq, void *dev)
214 {
215 	struct hisi_thermal_data *data = dev;
216 
217 	disable_irq_nosync(irq);
218 	data->irq_enabled = false;
219 
220 	return IRQ_WAKE_THREAD;
221 }
222 
223 static irqreturn_t hisi_thermal_alarm_irq_thread(int irq, void *dev)
224 {
225 	struct hisi_thermal_data *data = dev;
226 	struct hisi_thermal_sensor *sensor;
227 	int i;
228 
229 	mutex_lock(&data->thermal_lock);
230 	sensor = &data->sensors[data->irq_bind_sensor];
231 
232 	dev_crit(&data->pdev->dev, "THERMAL ALARM: T > %d\n",
233 		 sensor->thres_temp / 1000);
234 	mutex_unlock(&data->thermal_lock);
235 
236 	for (i = 0; i < HISI_MAX_SENSORS; i++) {
237 		if (!data->sensors[i].tzd)
238 			continue;
239 
240 		thermal_zone_device_update(data->sensors[i].tzd,
241 					   THERMAL_EVENT_UNSPECIFIED);
242 	}
243 
244 	return IRQ_HANDLED;
245 }
246 
247 static int hisi_thermal_register_sensor(struct platform_device *pdev,
248 					struct hisi_thermal_data *data,
249 					struct hisi_thermal_sensor *sensor,
250 					int index)
251 {
252 	int ret, i;
253 	const struct thermal_trip *trip;
254 
255 	sensor->id = index;
256 	sensor->thermal = data;
257 
258 	sensor->tzd = devm_thermal_zone_of_sensor_register(&pdev->dev,
259 				sensor->id, sensor, &hisi_of_thermal_ops);
260 	if (IS_ERR(sensor->tzd)) {
261 		ret = PTR_ERR(sensor->tzd);
262 		sensor->tzd = NULL;
263 		dev_err(&pdev->dev, "failed to register sensor id %d: %d\n",
264 			sensor->id, ret);
265 		return ret;
266 	}
267 
268 	trip = of_thermal_get_trip_points(sensor->tzd);
269 
270 	for (i = 0; i < of_thermal_get_ntrips(sensor->tzd); i++) {
271 		if (trip[i].type == THERMAL_TRIP_PASSIVE) {
272 			sensor->thres_temp = trip[i].temperature;
273 			break;
274 		}
275 	}
276 
277 	return 0;
278 }
279 
280 static const struct of_device_id of_hisi_thermal_match[] = {
281 	{ .compatible = "hisilicon,tsensor" },
282 	{ /* end */ }
283 };
284 MODULE_DEVICE_TABLE(of, of_hisi_thermal_match);
285 
286 static void hisi_thermal_toggle_sensor(struct hisi_thermal_sensor *sensor,
287 				       bool on)
288 {
289 	struct thermal_zone_device *tzd = sensor->tzd;
290 
291 	tzd->ops->set_mode(tzd,
292 		on ? THERMAL_DEVICE_ENABLED : THERMAL_DEVICE_DISABLED);
293 }
294 
295 static int hisi_thermal_probe(struct platform_device *pdev)
296 {
297 	struct hisi_thermal_data *data;
298 	struct resource *res;
299 	int i;
300 	int ret;
301 
302 	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
303 	if (!data)
304 		return -ENOMEM;
305 
306 	mutex_init(&data->thermal_lock);
307 	data->pdev = pdev;
308 
309 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
310 	data->regs = devm_ioremap_resource(&pdev->dev, res);
311 	if (IS_ERR(data->regs)) {
312 		dev_err(&pdev->dev, "failed to get io address\n");
313 		return PTR_ERR(data->regs);
314 	}
315 
316 	data->irq = platform_get_irq(pdev, 0);
317 	if (data->irq < 0)
318 		return data->irq;
319 
320 	ret = devm_request_threaded_irq(&pdev->dev, data->irq,
321 					hisi_thermal_alarm_irq,
322 					hisi_thermal_alarm_irq_thread,
323 					0, "hisi_thermal", data);
324 	if (ret < 0) {
325 		dev_err(&pdev->dev, "failed to request alarm irq: %d\n", ret);
326 		return ret;
327 	}
328 
329 	platform_set_drvdata(pdev, data);
330 
331 	data->clk = devm_clk_get(&pdev->dev, "thermal_clk");
332 	if (IS_ERR(data->clk)) {
333 		ret = PTR_ERR(data->clk);
334 		if (ret != -EPROBE_DEFER)
335 			dev_err(&pdev->dev,
336 				"failed to get thermal clk: %d\n", ret);
337 		return ret;
338 	}
339 
340 	/* enable clock for thermal */
341 	ret = clk_prepare_enable(data->clk);
342 	if (ret) {
343 		dev_err(&pdev->dev, "failed to enable thermal clk: %d\n", ret);
344 		return ret;
345 	}
346 
347 	hisi_thermal_enable_bind_irq_sensor(data);
348 	irq_get_irqchip_state(data->irq, IRQCHIP_STATE_MASKED,
349 			      &data->irq_enabled);
350 
351 	for (i = 0; i < HISI_MAX_SENSORS; ++i) {
352 		ret = hisi_thermal_register_sensor(pdev, data,
353 						   &data->sensors[i], i);
354 		if (ret)
355 			dev_err(&pdev->dev,
356 				"failed to register thermal sensor: %d\n", ret);
357 		else
358 			hisi_thermal_toggle_sensor(&data->sensors[i], true);
359 	}
360 
361 	return 0;
362 }
363 
364 static int hisi_thermal_remove(struct platform_device *pdev)
365 {
366 	struct hisi_thermal_data *data = platform_get_drvdata(pdev);
367 	int i;
368 
369 	for (i = 0; i < HISI_MAX_SENSORS; i++) {
370 		struct hisi_thermal_sensor *sensor = &data->sensors[i];
371 
372 		if (!sensor->tzd)
373 			continue;
374 
375 		hisi_thermal_toggle_sensor(sensor, false);
376 	}
377 
378 	hisi_thermal_disable_sensor(data);
379 	clk_disable_unprepare(data->clk);
380 
381 	return 0;
382 }
383 
384 #ifdef CONFIG_PM_SLEEP
385 static int hisi_thermal_suspend(struct device *dev)
386 {
387 	struct hisi_thermal_data *data = dev_get_drvdata(dev);
388 
389 	hisi_thermal_disable_sensor(data);
390 	data->irq_enabled = false;
391 
392 	clk_disable_unprepare(data->clk);
393 
394 	return 0;
395 }
396 
397 static int hisi_thermal_resume(struct device *dev)
398 {
399 	struct hisi_thermal_data *data = dev_get_drvdata(dev);
400 
401 	clk_prepare_enable(data->clk);
402 
403 	data->irq_enabled = true;
404 	hisi_thermal_enable_bind_irq_sensor(data);
405 
406 	return 0;
407 }
408 #endif
409 
410 static SIMPLE_DEV_PM_OPS(hisi_thermal_pm_ops,
411 			 hisi_thermal_suspend, hisi_thermal_resume);
412 
413 static struct platform_driver hisi_thermal_driver = {
414 	.driver = {
415 		.name		= "hisi_thermal",
416 		.pm		= &hisi_thermal_pm_ops,
417 		.of_match_table = of_hisi_thermal_match,
418 	},
419 	.probe	= hisi_thermal_probe,
420 	.remove	= hisi_thermal_remove,
421 };
422 
423 module_platform_driver(hisi_thermal_driver);
424 
425 MODULE_AUTHOR("Xinwei Kong <kong.kongxinwei@hisilicon.com>");
426 MODULE_AUTHOR("Leo Yan <leo.yan@linaro.org>");
427 MODULE_DESCRIPTION("Hisilicon thermal driver");
428 MODULE_LICENSE("GPL v2");
429