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 + (step * 200 / 255)) * 1000;
72 }
73 
74 static inline long _temp_to_step(long temp)
75 {
76 	return ((temp / 1000 - HISI_TEMP_BASE) * 255 / 200);
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, long *temp)
159 {
160 	struct hisi_thermal_sensor *sensor = _sensor;
161 	struct hisi_thermal_data *data = sensor->thermal;
162 
163 	int sensor_id = 0, 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].sensor_temp >= max_temp) {
172 			max_temp = data->sensors[i].sensor_temp;
173 			sensor_id = i;
174 		}
175 	}
176 
177 	mutex_lock(&data->thermal_lock);
178 	data->irq_bind_sensor = sensor_id;
179 	mutex_unlock(&data->thermal_lock);
180 
181 	dev_dbg(&data->pdev->dev, "id=%d, irq=%d, temp=%ld, thres=%d\n",
182 		sensor->id, data->irq_enabled, *temp, sensor->thres_temp);
183 	/*
184 	 * Bind irq to sensor for two cases:
185 	 *   Reenable alarm IRQ if temperature below threshold;
186 	 *   if irq has been enabled, always set it;
187 	 */
188 	if (data->irq_enabled) {
189 		hisi_thermal_enable_bind_irq_sensor(data);
190 		return 0;
191 	}
192 
193 	if (max_temp < sensor->thres_temp) {
194 		data->irq_enabled = true;
195 		hisi_thermal_enable_bind_irq_sensor(data);
196 		enable_irq(data->irq);
197 	}
198 
199 	return 0;
200 }
201 
202 static struct thermal_zone_of_device_ops hisi_of_thermal_ops = {
203 	.get_temp = hisi_thermal_get_temp,
204 };
205 
206 static irqreturn_t hisi_thermal_alarm_irq(int irq, void *dev)
207 {
208 	struct hisi_thermal_data *data = dev;
209 
210 	disable_irq_nosync(irq);
211 	data->irq_enabled = false;
212 
213 	return IRQ_WAKE_THREAD;
214 }
215 
216 static irqreturn_t hisi_thermal_alarm_irq_thread(int irq, void *dev)
217 {
218 	struct hisi_thermal_data *data = dev;
219 	struct hisi_thermal_sensor *sensor;
220 	int i;
221 
222 	mutex_lock(&data->thermal_lock);
223 	sensor = &data->sensors[data->irq_bind_sensor];
224 
225 	dev_crit(&data->pdev->dev, "THERMAL ALARM: T > %d\n",
226 		 sensor->thres_temp / 1000);
227 	mutex_unlock(&data->thermal_lock);
228 
229 	for (i = 0; i < HISI_MAX_SENSORS; i++)
230 		thermal_zone_device_update(data->sensors[i].tzd);
231 
232 	return IRQ_HANDLED;
233 }
234 
235 static int hisi_thermal_register_sensor(struct platform_device *pdev,
236 					struct hisi_thermal_data *data,
237 					struct hisi_thermal_sensor *sensor,
238 					int index)
239 {
240 	int ret, i;
241 	const struct thermal_trip *trip;
242 
243 	sensor->id = index;
244 	sensor->thermal = data;
245 
246 	sensor->tzd = thermal_zone_of_sensor_register(&pdev->dev, sensor->id,
247 				sensor, &hisi_of_thermal_ops);
248 	if (IS_ERR(sensor->tzd)) {
249 		ret = PTR_ERR(sensor->tzd);
250 		dev_err(&pdev->dev, "failed to register sensor id %d: %d\n",
251 			sensor->id, ret);
252 		return ret;
253 	}
254 
255 	trip = of_thermal_get_trip_points(sensor->tzd);
256 
257 	for (i = 0; i < of_thermal_get_ntrips(sensor->tzd); i++) {
258 		if (trip[i].type == THERMAL_TRIP_PASSIVE) {
259 			sensor->thres_temp = trip[i].temperature;
260 			break;
261 		}
262 	}
263 
264 	return 0;
265 }
266 
267 static const struct of_device_id of_hisi_thermal_match[] = {
268 	{ .compatible = "hisilicon,tsensor" },
269 	{ /* end */ }
270 };
271 MODULE_DEVICE_TABLE(of, of_hisi_thermal_match);
272 
273 static void hisi_thermal_toggle_sensor(struct hisi_thermal_sensor *sensor,
274 				       bool on)
275 {
276 	struct thermal_zone_device *tzd = sensor->tzd;
277 
278 	tzd->ops->set_mode(tzd,
279 		on ? THERMAL_DEVICE_ENABLED : THERMAL_DEVICE_DISABLED);
280 }
281 
282 static int hisi_thermal_probe(struct platform_device *pdev)
283 {
284 	struct hisi_thermal_data *data;
285 	struct resource *res;
286 	int i;
287 	int ret;
288 
289 	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
290 	if (!data)
291 		return -ENOMEM;
292 
293 	mutex_init(&data->thermal_lock);
294 	data->pdev = pdev;
295 
296 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
297 	data->regs = devm_ioremap_resource(&pdev->dev, res);
298 	if (IS_ERR(data->regs)) {
299 		dev_err(&pdev->dev, "failed to get io address\n");
300 		return PTR_ERR(data->regs);
301 	}
302 
303 	data->irq = platform_get_irq(pdev, 0);
304 	if (data->irq < 0)
305 		return data->irq;
306 
307 	ret = devm_request_threaded_irq(&pdev->dev, data->irq,
308 					hisi_thermal_alarm_irq,
309 					hisi_thermal_alarm_irq_thread,
310 					0, "hisi_thermal", data);
311 	if (ret < 0) {
312 		dev_err(&pdev->dev, "failed to request alarm irq: %d\n", ret);
313 		return ret;
314 	}
315 
316 	platform_set_drvdata(pdev, data);
317 
318 	data->clk = devm_clk_get(&pdev->dev, "thermal_clk");
319 	if (IS_ERR(data->clk)) {
320 		ret = PTR_ERR(data->clk);
321 		if (ret != -EPROBE_DEFER)
322 			dev_err(&pdev->dev,
323 				"failed to get thermal clk: %d\n", ret);
324 		return ret;
325 	}
326 
327 	/* enable clock for thermal */
328 	ret = clk_prepare_enable(data->clk);
329 	if (ret) {
330 		dev_err(&pdev->dev, "failed to enable thermal clk: %d\n", ret);
331 		return ret;
332 	}
333 
334 	for (i = 0; i < HISI_MAX_SENSORS; ++i) {
335 		ret = hisi_thermal_register_sensor(pdev, data,
336 						   &data->sensors[i], i);
337 		if (ret) {
338 			dev_err(&pdev->dev,
339 				"failed to register thermal sensor: %d\n", ret);
340 			goto err_get_sensor_data;
341 		}
342 	}
343 
344 	hisi_thermal_enable_bind_irq_sensor(data);
345 	data->irq_enabled = true;
346 
347 	for (i = 0; i < HISI_MAX_SENSORS; i++)
348 		hisi_thermal_toggle_sensor(&data->sensors[i], true);
349 
350 	return 0;
351 
352 err_get_sensor_data:
353 	clk_disable_unprepare(data->clk);
354 
355 	return ret;
356 }
357 
358 static int hisi_thermal_remove(struct platform_device *pdev)
359 {
360 	struct hisi_thermal_data *data = platform_get_drvdata(pdev);
361 	int i;
362 
363 	for (i = 0; i < HISI_MAX_SENSORS; i++) {
364 		struct hisi_thermal_sensor *sensor = &data->sensors[i];
365 
366 		hisi_thermal_toggle_sensor(sensor, false);
367 		thermal_zone_of_sensor_unregister(&pdev->dev, sensor->tzd);
368 	}
369 
370 	hisi_thermal_disable_sensor(data);
371 	clk_disable_unprepare(data->clk);
372 
373 	return 0;
374 }
375 
376 #ifdef CONFIG_PM_SLEEP
377 static int hisi_thermal_suspend(struct device *dev)
378 {
379 	struct hisi_thermal_data *data = dev_get_drvdata(dev);
380 
381 	hisi_thermal_disable_sensor(data);
382 	data->irq_enabled = false;
383 
384 	clk_disable_unprepare(data->clk);
385 
386 	return 0;
387 }
388 
389 static int hisi_thermal_resume(struct device *dev)
390 {
391 	struct hisi_thermal_data *data = dev_get_drvdata(dev);
392 
393 	clk_prepare_enable(data->clk);
394 
395 	data->irq_enabled = true;
396 	hisi_thermal_enable_bind_irq_sensor(data);
397 
398 	return 0;
399 }
400 #endif
401 
402 static SIMPLE_DEV_PM_OPS(hisi_thermal_pm_ops,
403 			 hisi_thermal_suspend, hisi_thermal_resume);
404 
405 static struct platform_driver hisi_thermal_driver = {
406 	.driver = {
407 		.name		= "hisi_thermal",
408 		.owner		= THIS_MODULE,
409 		.pm		= &hisi_thermal_pm_ops,
410 		.of_match_table = of_hisi_thermal_match,
411 	},
412 	.probe	= hisi_thermal_probe,
413 	.remove	= hisi_thermal_remove,
414 };
415 
416 module_platform_driver(hisi_thermal_driver);
417 
418 MODULE_AUTHOR("Xinwei Kong <kong.kongxinwei@hisilicon.com>");
419 MODULE_AUTHOR("Leo Yan <leo.yan@linaro.org>");
420 MODULE_DESCRIPTION("Hisilicon thermal driver");
421 MODULE_LICENSE("GPL v2");
422