1/*
2 * ST Thermal Sensor Driver core routines
3 * Author: Ajit Pal Singh <ajitpal.singh@st.com>
4 *
5 * Copyright (C) 2003-2014 STMicroelectronics (R&D) Limited
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 */
13
14#include <linux/clk.h>
15#include <linux/module.h>
16#include <linux/of.h>
17#include <linux/of_device.h>
18
19#include "st_thermal.h"
20
21/* The Thermal Framework expects millidegrees */
22#define mcelsius(temp)			((temp) * 1000)
23
24/*
25 * Function to allocate regfields which are common
26 * between syscfg and memory mapped based sensors
27 */
28static int st_thermal_alloc_regfields(struct st_thermal_sensor *sensor)
29{
30	struct device *dev = sensor->dev;
31	struct regmap *regmap = sensor->regmap;
32	const struct reg_field *reg_fields = sensor->cdata->reg_fields;
33
34	sensor->dcorrect = devm_regmap_field_alloc(dev, regmap,
35						   reg_fields[DCORRECT]);
36
37	sensor->overflow = devm_regmap_field_alloc(dev, regmap,
38						   reg_fields[OVERFLOW]);
39
40	sensor->temp_data = devm_regmap_field_alloc(dev, regmap,
41						    reg_fields[DATA]);
42
43	if (IS_ERR(sensor->dcorrect) ||
44	    IS_ERR(sensor->overflow) ||
45	    IS_ERR(sensor->temp_data)) {
46		dev_err(dev, "failed to allocate common regfields\n");
47		return -EINVAL;
48	}
49
50	return sensor->ops->alloc_regfields(sensor);
51}
52
53static int st_thermal_sensor_on(struct st_thermal_sensor *sensor)
54{
55	int ret;
56	struct device *dev = sensor->dev;
57
58	ret = clk_prepare_enable(sensor->clk);
59	if (ret) {
60		dev_err(dev, "failed to enable clk\n");
61		return ret;
62	}
63
64	ret = sensor->ops->power_ctrl(sensor, POWER_ON);
65	if (ret) {
66		dev_err(dev, "failed to power on sensor\n");
67		clk_disable_unprepare(sensor->clk);
68	}
69
70	return ret;
71}
72
73static int st_thermal_sensor_off(struct st_thermal_sensor *sensor)
74{
75	int ret;
76
77	ret = sensor->ops->power_ctrl(sensor, POWER_OFF);
78	if (ret)
79		return ret;
80
81	clk_disable_unprepare(sensor->clk);
82
83	return 0;
84}
85
86static int st_thermal_calibration(struct st_thermal_sensor *sensor)
87{
88	int ret;
89	unsigned int val;
90	struct device *dev = sensor->dev;
91
92	/* Check if sensor calibration data is already written */
93	ret = regmap_field_read(sensor->dcorrect, &val);
94	if (ret) {
95		dev_err(dev, "failed to read calibration data\n");
96		return ret;
97	}
98
99	if (!val) {
100		/*
101		 * Sensor calibration value not set by bootloader,
102		 * default calibration data to be used
103		 */
104		ret = regmap_field_write(sensor->dcorrect,
105					 sensor->cdata->calibration_val);
106		if (ret)
107			dev_err(dev, "failed to set calibration data\n");
108	}
109
110	return ret;
111}
112
113/* Callback to get temperature from HW*/
114static int st_thermal_get_temp(struct thermal_zone_device *th,
115		unsigned long *temperature)
116{
117	struct st_thermal_sensor *sensor = th->devdata;
118	struct device *dev = sensor->dev;
119	unsigned int temp;
120	unsigned int overflow;
121	int ret;
122
123	ret = regmap_field_read(sensor->overflow, &overflow);
124	if (ret)
125		return ret;
126	if (overflow)
127		return -EIO;
128
129	ret = regmap_field_read(sensor->temp_data, &temp);
130	if (ret)
131		return ret;
132
133	temp += sensor->cdata->temp_adjust_val;
134	temp = mcelsius(temp);
135
136	dev_dbg(dev, "temperature: %d\n", temp);
137
138	*temperature = temp;
139
140	return 0;
141}
142
143static int st_thermal_get_trip_type(struct thermal_zone_device *th,
144				int trip, enum thermal_trip_type *type)
145{
146	struct st_thermal_sensor *sensor = th->devdata;
147	struct device *dev = sensor->dev;
148
149	switch (trip) {
150	case 0:
151		*type = THERMAL_TRIP_CRITICAL;
152		break;
153	default:
154		dev_err(dev, "invalid trip point\n");
155		return -EINVAL;
156	}
157
158	return 0;
159}
160
161static int st_thermal_get_trip_temp(struct thermal_zone_device *th,
162				    int trip, unsigned long *temp)
163{
164	struct st_thermal_sensor *sensor = th->devdata;
165	struct device *dev = sensor->dev;
166
167	switch (trip) {
168	case 0:
169		*temp = mcelsius(sensor->cdata->crit_temp);
170		break;
171	default:
172		dev_err(dev, "Invalid trip point\n");
173		return -EINVAL;
174	}
175
176	return 0;
177}
178
179static struct thermal_zone_device_ops st_tz_ops = {
180	.get_temp	= st_thermal_get_temp,
181	.get_trip_type	= st_thermal_get_trip_type,
182	.get_trip_temp	= st_thermal_get_trip_temp,
183};
184
185int st_thermal_register(struct platform_device *pdev,
186			const struct of_device_id *st_thermal_of_match)
187{
188	struct st_thermal_sensor *sensor;
189	struct device *dev = &pdev->dev;
190	struct device_node *np = dev->of_node;
191	const struct of_device_id *match;
192
193	int polling_delay;
194	int ret;
195
196	if (!np) {
197		dev_err(dev, "device tree node not found\n");
198		return -EINVAL;
199	}
200
201	sensor = devm_kzalloc(dev, sizeof(*sensor), GFP_KERNEL);
202	if (!sensor)
203		return -ENOMEM;
204
205	sensor->dev = dev;
206
207	match = of_match_device(st_thermal_of_match, dev);
208	if (!(match && match->data))
209		return -EINVAL;
210
211	sensor->cdata = match->data;
212	if (!sensor->cdata->ops)
213		return -EINVAL;
214
215	sensor->ops = sensor->cdata->ops;
216
217	ret = sensor->ops->regmap_init(sensor);
218	if (ret)
219		return ret;
220
221	ret = st_thermal_alloc_regfields(sensor);
222	if (ret)
223		return ret;
224
225	sensor->clk = devm_clk_get(dev, "thermal");
226	if (IS_ERR(sensor->clk)) {
227		dev_err(dev, "failed to fetch clock\n");
228		return PTR_ERR(sensor->clk);
229	}
230
231	if (sensor->ops->register_enable_irq) {
232		ret = sensor->ops->register_enable_irq(sensor);
233		if (ret)
234			return ret;
235	}
236
237	ret = st_thermal_sensor_on(sensor);
238	if (ret)
239		return ret;
240
241	ret = st_thermal_calibration(sensor);
242	if (ret)
243		goto sensor_off;
244
245	polling_delay = sensor->ops->register_enable_irq ? 0 : 1000;
246
247	sensor->thermal_dev =
248		thermal_zone_device_register(dev_name(dev), 1, 0, sensor,
249					     &st_tz_ops, NULL, 0, polling_delay);
250	if (IS_ERR(sensor->thermal_dev)) {
251		dev_err(dev, "failed to register thermal zone device\n");
252		ret = PTR_ERR(sensor->thermal_dev);
253		goto sensor_off;
254	}
255
256	platform_set_drvdata(pdev, sensor);
257
258	return 0;
259
260sensor_off:
261	st_thermal_sensor_off(sensor);
262
263	return ret;
264}
265EXPORT_SYMBOL_GPL(st_thermal_register);
266
267int st_thermal_unregister(struct platform_device *pdev)
268{
269	struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);
270
271	st_thermal_sensor_off(sensor);
272	thermal_zone_device_unregister(sensor->thermal_dev);
273
274	return 0;
275}
276EXPORT_SYMBOL_GPL(st_thermal_unregister);
277
278#ifdef CONFIG_PM_SLEEP
279static int st_thermal_suspend(struct device *dev)
280{
281	struct platform_device *pdev = to_platform_device(dev);
282	struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);
283
284	return st_thermal_sensor_off(sensor);
285}
286
287static int st_thermal_resume(struct device *dev)
288{
289	int ret;
290	struct platform_device *pdev = to_platform_device(dev);
291	struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);
292
293	ret = st_thermal_sensor_on(sensor);
294	if (ret)
295		return ret;
296
297	ret = st_thermal_calibration(sensor);
298	if (ret)
299		return ret;
300
301	if (sensor->ops->enable_irq) {
302		ret = sensor->ops->enable_irq(sensor);
303		if (ret)
304			return ret;
305	}
306
307	return 0;
308}
309#endif
310
311SIMPLE_DEV_PM_OPS(st_thermal_pm_ops, st_thermal_suspend, st_thermal_resume);
312EXPORT_SYMBOL_GPL(st_thermal_pm_ops);
313
314MODULE_AUTHOR("STMicroelectronics (R&D) Limited <ajitpal.singh@st.com>");
315MODULE_DESCRIPTION("STMicroelectronics STi SoC Thermal Sensor Driver");
316MODULE_LICENSE("GPL v2");
317