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
 43struct 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
 52struct 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 */
 65static 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
 74static inline long _temp_to_step(long temp)
 75{
 76	return ((temp - HISI_TEMP_BASE * 1000) * 255) / 200000;
 77}
 78
 79static 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
109static 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
146static 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
158static 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
209static struct thermal_zone_of_device_ops hisi_of_thermal_ops = {
210	.get_temp = hisi_thermal_get_temp,
211};
212
213static 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
223static 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
247static 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
280static const struct of_device_id of_hisi_thermal_match[] = {
281	{ .compatible = "hisilicon,tsensor" },
282	{ /* end */ }
283};
284MODULE_DEVICE_TABLE(of, of_hisi_thermal_match);
285
286static 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
295static 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
364static 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
385static 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
397static 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
410static SIMPLE_DEV_PM_OPS(hisi_thermal_pm_ops,
411			 hisi_thermal_suspend, hisi_thermal_resume);
412
413static 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
423module_platform_driver(hisi_thermal_driver);
424
425MODULE_AUTHOR("Xinwei Kong <kong.kongxinwei@hisilicon.com>");
426MODULE_AUTHOR("Leo Yan <leo.yan@linaro.org>");
427MODULE_DESCRIPTION("Hisilicon thermal driver");
428MODULE_LICENSE("GPL v2");