summaryrefslogtreecommitdiffstats
path: root/drivers/thermal/st/st_thermal.c
blob: be637e6b01d217f9ab54929fbb93322fb5ca086a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
/*
 * ST Thermal Sensor Driver core routines
 * Author: Ajit Pal Singh <ajitpal.singh@st.com>
 *
 * Copyright (C) 2003-2014 STMicroelectronics (R&D) Limited
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 */

#include <linux/clk.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>

#include "st_thermal.h"

/* The Thermal Framework expects millidegrees */
#define mcelsius(temp)			((temp) * 1000)

/*
 * Function to allocate regfields which are common
 * between syscfg and memory mapped based sensors
 */
static int st_thermal_alloc_regfields(struct st_thermal_sensor *sensor)
{
	struct device *dev = sensor->dev;
	struct regmap *regmap = sensor->regmap;
	const struct reg_field *reg_fields = sensor->cdata->reg_fields;

	sensor->dcorrect = devm_regmap_field_alloc(dev, regmap,
						   reg_fields[DCORRECT]);

	sensor->overflow = devm_regmap_field_alloc(dev, regmap,
						   reg_fields[OVERFLOW]);

	sensor->temp_data = devm_regmap_field_alloc(dev, regmap,
						    reg_fields[DATA]);

	if (IS_ERR(sensor->dcorrect) ||
	    IS_ERR(sensor->overflow) ||
	    IS_ERR(sensor->temp_data)) {
		dev_err(dev, "failed to allocate common regfields\n");
		return -EINVAL;
	}

	return sensor->ops->alloc_regfields(sensor);
}

static int st_thermal_sensor_on(struct st_thermal_sensor *sensor)
{
	int ret;
	struct device *dev = sensor->dev;

	ret = clk_prepare_enable(sensor->clk);
	if (ret) {
		dev_err(dev, "failed to enable clk\n");
		return ret;
	}

	ret = sensor->ops->power_ctrl(sensor, POWER_ON);
	if (ret) {
		dev_err(dev, "failed to power on sensor\n");
		clk_disable_unprepare(sensor->clk);
	}

	return ret;
}

static int st_thermal_sensor_off(struct st_thermal_sensor *sensor)
{
	int ret;

	ret = sensor->ops->power_ctrl(sensor, POWER_OFF);
	if (ret)
		return ret;

	clk_disable_unprepare(sensor->clk);

	return 0;
}

static int st_thermal_calibration(struct st_thermal_sensor *sensor)
{
	int ret;
	unsigned int val;
	struct device *dev = sensor->dev;

	/* Check if sensor calibration data is already written */
	ret = regmap_field_read(sensor->dcorrect, &val);
	if (ret) {
		dev_err(dev, "failed to read calibration data\n");
		return ret;
	}

	if (!val) {
		/*
		 * Sensor calibration value not set by bootloader,
		 * default calibration data to be used
		 */
		ret = regmap_field_write(sensor->dcorrect,
					 sensor->cdata->calibration_val);
		if (ret)
			dev_err(dev, "failed to set calibration data\n");
	}

	return ret;
}

/* Callback to get temperature from HW*/
static int st_thermal_get_temp(struct thermal_zone_device *th, int *temperature)
{
	struct st_thermal_sensor *sensor = th->devdata;
	struct device *dev = sensor->dev;
	unsigned int temp;
	unsigned int overflow;
	int ret;

	ret = regmap_field_read(sensor->overflow, &overflow);
	if (ret)
		return ret;
	if (overflow)
		return -EIO;

	ret = regmap_field_read(sensor->temp_data, &temp);
	if (ret)
		return ret;

	temp += sensor->cdata->temp_adjust_val;
	temp = mcelsius(temp);

	dev_dbg(dev, "temperature: %d\n", temp);

	*temperature = temp;

	return 0;
}

static int st_thermal_get_trip_type(struct thermal_zone_device *th,
				int trip, enum thermal_trip_type *type)
{
	struct st_thermal_sensor *sensor = th->devdata;
	struct device *dev = sensor->dev;

	switch (trip) {
	case 0:
		*type = THERMAL_TRIP_CRITICAL;
		break;
	default:
		dev_err(dev, "invalid trip point\n");
		return -EINVAL;
	}

	return 0;
}

static int st_thermal_get_trip_temp(struct thermal_zone_device *th,
				    int trip, int *temp)
{
	struct st_thermal_sensor *sensor = th->devdata;
	struct device *dev = sensor->dev;

	switch (trip) {
	case 0:
		*temp = mcelsius(sensor->cdata->crit_temp);
		break;
	default:
		dev_err(dev, "Invalid trip point\n");
		return -EINVAL;
	}

	return 0;
}

static struct thermal_zone_device_ops st_tz_ops = {
	.get_temp	= st_thermal_get_temp,
	.get_trip_type	= st_thermal_get_trip_type,
	.get_trip_temp	= st_thermal_get_trip_temp,
};

int st_thermal_register(struct platform_device *pdev,
			const struct of_device_id *st_thermal_of_match)
{
	struct st_thermal_sensor *sensor;
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	const struct of_device_id *match;

	int polling_delay;
	int ret;

	if (!np) {
		dev_err(dev, "device tree node not found\n");
		return -EINVAL;
	}

	sensor = devm_kzalloc(dev, sizeof(*sensor), GFP_KERNEL);
	if (!sensor)
		return -ENOMEM;

	sensor->dev = dev;

	match = of_match_device(st_thermal_of_match, dev);
	if (!(match && match->data))
		return -EINVAL;

	sensor->cdata = match->data;
	if (!sensor->cdata->ops)
		return -EINVAL;

	sensor->ops = sensor->cdata->ops;

	ret = (sensor->ops->regmap_init)(sensor);
	if (ret)
		return ret;

	ret = st_thermal_alloc_regfields(sensor);
	if (ret)
		return ret;

	sensor->clk = devm_clk_get(dev, "thermal");
	if (IS_ERR(sensor->clk)) {
		dev_err(dev, "failed to fetch clock\n");
		return PTR_ERR(sensor->clk);
	}

	if (sensor->ops->register_enable_irq) {
		ret = sensor->ops->register_enable_irq(sensor);
		if (ret)
			return ret;
	}

	ret = st_thermal_sensor_on(sensor);
	if (ret)
		return ret;

	ret = st_thermal_calibration(sensor);
	if (ret)
		goto sensor_off;

	polling_delay = sensor->ops->register_enable_irq ? 0 : 1000;

	sensor->thermal_dev =
		thermal_zone_device_register(dev_name(dev), 1, 0, sensor,
					     &st_tz_ops, NULL, 0, polling_delay);
	if (IS_ERR(sensor->thermal_dev)) {
		dev_err(dev, "failed to register thermal zone device\n");
		ret = PTR_ERR(sensor->thermal_dev);
		goto sensor_off;
	}

	platform_set_drvdata(pdev, sensor);

	return 0;

sensor_off:
	st_thermal_sensor_off(sensor);

	return ret;
}
EXPORT_SYMBOL_GPL(st_thermal_register);

int st_thermal_unregister(struct platform_device *pdev)
{
	struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);

	st_thermal_sensor_off(sensor);
	thermal_zone_device_unregister(sensor->thermal_dev);

	return 0;
}
EXPORT_SYMBOL_GPL(st_thermal_unregister);

#ifdef CONFIG_PM_SLEEP
static int st_thermal_suspend(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);

	return st_thermal_sensor_off(sensor);
}

static int st_thermal_resume(struct device *dev)
{
	int ret;
	struct platform_device *pdev = to_platform_device(dev);
	struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);

	ret = st_thermal_sensor_on(sensor);
	if (ret)
		return ret;

	ret = st_thermal_calibration(sensor);
	if (ret)
		return ret;

	if (sensor->ops->enable_irq) {
		ret = sensor->ops->enable_irq(sensor);
		if (ret)
			return ret;
	}

	return 0;
}
#endif

SIMPLE_DEV_PM_OPS(st_thermal_pm_ops, st_thermal_suspend, st_thermal_resume);
EXPORT_SYMBOL_GPL(st_thermal_pm_ops);

MODULE_AUTHOR("STMicroelectronics (R&D) Limited <ajitpal.singh@st.com>");
MODULE_DESCRIPTION("STMicroelectronics STi SoC Thermal Sensor Driver");
MODULE_LICENSE("GPL v2");
OpenPOWER on IntegriCloud