1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * ST Thermal Sensor Driver core routines
4  * Author: Ajit Pal Singh <ajitpal.singh@st.com>
5  *
6  * Copyright (C) 2003-2014 STMicroelectronics (R&D) Limited
7  */
8 
9 #include <linux/clk.h>
10 #include <linux/module.h>
11 #include <linux/of.h>
12 #include <linux/of_device.h>
13 
14 #include "st_thermal.h"
15 
16 /* The Thermal Framework expects millidegrees */
17 #define mcelsius(temp)			((temp) * 1000)
18 
19 /*
20  * Function to allocate regfields which are common
21  * between syscfg and memory mapped based sensors
22  */
st_thermal_alloc_regfields(struct st_thermal_sensor * sensor)23 static int st_thermal_alloc_regfields(struct st_thermal_sensor *sensor)
24 {
25 	struct device *dev = sensor->dev;
26 	struct regmap *regmap = sensor->regmap;
27 	const struct reg_field *reg_fields = sensor->cdata->reg_fields;
28 
29 	sensor->dcorrect = devm_regmap_field_alloc(dev, regmap,
30 						   reg_fields[DCORRECT]);
31 
32 	sensor->overflow = devm_regmap_field_alloc(dev, regmap,
33 						   reg_fields[OVERFLOW]);
34 
35 	sensor->temp_data = devm_regmap_field_alloc(dev, regmap,
36 						    reg_fields[DATA]);
37 
38 	if (IS_ERR(sensor->dcorrect) ||
39 	    IS_ERR(sensor->overflow) ||
40 	    IS_ERR(sensor->temp_data)) {
41 		dev_err(dev, "failed to allocate common regfields\n");
42 		return -EINVAL;
43 	}
44 
45 	return sensor->ops->alloc_regfields(sensor);
46 }
47 
st_thermal_sensor_on(struct st_thermal_sensor * sensor)48 static int st_thermal_sensor_on(struct st_thermal_sensor *sensor)
49 {
50 	int ret;
51 	struct device *dev = sensor->dev;
52 
53 	ret = clk_prepare_enable(sensor->clk);
54 	if (ret) {
55 		dev_err(dev, "failed to enable clk\n");
56 		return ret;
57 	}
58 
59 	ret = sensor->ops->power_ctrl(sensor, POWER_ON);
60 	if (ret) {
61 		dev_err(dev, "failed to power on sensor\n");
62 		clk_disable_unprepare(sensor->clk);
63 	}
64 
65 	return ret;
66 }
67 
st_thermal_sensor_off(struct st_thermal_sensor * sensor)68 static int st_thermal_sensor_off(struct st_thermal_sensor *sensor)
69 {
70 	int ret;
71 
72 	ret = sensor->ops->power_ctrl(sensor, POWER_OFF);
73 	if (ret)
74 		return ret;
75 
76 	clk_disable_unprepare(sensor->clk);
77 
78 	return 0;
79 }
80 
st_thermal_calibration(struct st_thermal_sensor * sensor)81 static int st_thermal_calibration(struct st_thermal_sensor *sensor)
82 {
83 	int ret;
84 	unsigned int val;
85 	struct device *dev = sensor->dev;
86 
87 	/* Check if sensor calibration data is already written */
88 	ret = regmap_field_read(sensor->dcorrect, &val);
89 	if (ret) {
90 		dev_err(dev, "failed to read calibration data\n");
91 		return ret;
92 	}
93 
94 	if (!val) {
95 		/*
96 		 * Sensor calibration value not set by bootloader,
97 		 * default calibration data to be used
98 		 */
99 		ret = regmap_field_write(sensor->dcorrect,
100 					 sensor->cdata->calibration_val);
101 		if (ret)
102 			dev_err(dev, "failed to set calibration data\n");
103 	}
104 
105 	return ret;
106 }
107 
108 /* Callback to get temperature from HW*/
st_thermal_get_temp(struct thermal_zone_device * th,int * temperature)109 static int st_thermal_get_temp(struct thermal_zone_device *th, int *temperature)
110 {
111 	struct st_thermal_sensor *sensor = th->devdata;
112 	struct device *dev = sensor->dev;
113 	unsigned int temp;
114 	unsigned int overflow;
115 	int ret;
116 
117 	ret = regmap_field_read(sensor->overflow, &overflow);
118 	if (ret)
119 		return ret;
120 	if (overflow)
121 		return -EIO;
122 
123 	ret = regmap_field_read(sensor->temp_data, &temp);
124 	if (ret)
125 		return ret;
126 
127 	temp += sensor->cdata->temp_adjust_val;
128 	temp = mcelsius(temp);
129 
130 	dev_dbg(dev, "temperature: %d\n", temp);
131 
132 	*temperature = temp;
133 
134 	return 0;
135 }
136 
st_thermal_get_trip_type(struct thermal_zone_device * th,int trip,enum thermal_trip_type * type)137 static int st_thermal_get_trip_type(struct thermal_zone_device *th,
138 				int trip, enum thermal_trip_type *type)
139 {
140 	struct st_thermal_sensor *sensor = th->devdata;
141 	struct device *dev = sensor->dev;
142 
143 	switch (trip) {
144 	case 0:
145 		*type = THERMAL_TRIP_CRITICAL;
146 		break;
147 	default:
148 		dev_err(dev, "invalid trip point\n");
149 		return -EINVAL;
150 	}
151 
152 	return 0;
153 }
154 
st_thermal_get_trip_temp(struct thermal_zone_device * th,int trip,int * temp)155 static int st_thermal_get_trip_temp(struct thermal_zone_device *th,
156 				    int trip, int *temp)
157 {
158 	struct st_thermal_sensor *sensor = th->devdata;
159 	struct device *dev = sensor->dev;
160 
161 	switch (trip) {
162 	case 0:
163 		*temp = mcelsius(sensor->cdata->crit_temp);
164 		break;
165 	default:
166 		dev_err(dev, "Invalid trip point\n");
167 		return -EINVAL;
168 	}
169 
170 	return 0;
171 }
172 
173 static struct thermal_zone_device_ops st_tz_ops = {
174 	.get_temp	= st_thermal_get_temp,
175 	.get_trip_type	= st_thermal_get_trip_type,
176 	.get_trip_temp	= st_thermal_get_trip_temp,
177 };
178 
st_thermal_register(struct platform_device * pdev,const struct of_device_id * st_thermal_of_match)179 int st_thermal_register(struct platform_device *pdev,
180 			const struct of_device_id *st_thermal_of_match)
181 {
182 	struct st_thermal_sensor *sensor;
183 	struct device *dev = &pdev->dev;
184 	struct device_node *np = dev->of_node;
185 	const struct of_device_id *match;
186 
187 	int polling_delay;
188 	int ret;
189 
190 	if (!np) {
191 		dev_err(dev, "device tree node not found\n");
192 		return -EINVAL;
193 	}
194 
195 	sensor = devm_kzalloc(dev, sizeof(*sensor), GFP_KERNEL);
196 	if (!sensor)
197 		return -ENOMEM;
198 
199 	sensor->dev = dev;
200 
201 	match = of_match_device(st_thermal_of_match, dev);
202 	if (!(match && match->data))
203 		return -EINVAL;
204 
205 	sensor->cdata = match->data;
206 	if (!sensor->cdata->ops)
207 		return -EINVAL;
208 
209 	sensor->ops = sensor->cdata->ops;
210 
211 	ret = (sensor->ops->regmap_init)(sensor);
212 	if (ret)
213 		return ret;
214 
215 	ret = st_thermal_alloc_regfields(sensor);
216 	if (ret)
217 		return ret;
218 
219 	sensor->clk = devm_clk_get(dev, "thermal");
220 	if (IS_ERR(sensor->clk)) {
221 		dev_err(dev, "failed to fetch clock\n");
222 		return PTR_ERR(sensor->clk);
223 	}
224 
225 	if (sensor->ops->register_enable_irq) {
226 		ret = sensor->ops->register_enable_irq(sensor);
227 		if (ret)
228 			return ret;
229 	}
230 
231 	ret = st_thermal_sensor_on(sensor);
232 	if (ret)
233 		return ret;
234 
235 	ret = st_thermal_calibration(sensor);
236 	if (ret)
237 		goto sensor_off;
238 
239 	polling_delay = sensor->ops->register_enable_irq ? 0 : 1000;
240 
241 	sensor->thermal_dev =
242 		thermal_zone_device_register(dev_name(dev), 1, 0, sensor,
243 					     &st_tz_ops, NULL, 0, polling_delay);
244 	if (IS_ERR(sensor->thermal_dev)) {
245 		dev_err(dev, "failed to register thermal zone device\n");
246 		ret = PTR_ERR(sensor->thermal_dev);
247 		goto sensor_off;
248 	}
249 	ret = thermal_zone_device_enable(sensor->thermal_dev);
250 	if (ret)
251 		goto tzd_unregister;
252 
253 	platform_set_drvdata(pdev, sensor);
254 
255 	return 0;
256 
257 tzd_unregister:
258 	thermal_zone_device_unregister(sensor->thermal_dev);
259 sensor_off:
260 	st_thermal_sensor_off(sensor);
261 
262 	return ret;
263 }
264 EXPORT_SYMBOL_GPL(st_thermal_register);
265 
st_thermal_unregister(struct platform_device * pdev)266 int st_thermal_unregister(struct platform_device *pdev)
267 {
268 	struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);
269 
270 	st_thermal_sensor_off(sensor);
271 	thermal_zone_device_unregister(sensor->thermal_dev);
272 
273 	return 0;
274 }
275 EXPORT_SYMBOL_GPL(st_thermal_unregister);
276 
277 #ifdef CONFIG_PM_SLEEP
st_thermal_suspend(struct device * dev)278 static int st_thermal_suspend(struct device *dev)
279 {
280 	struct st_thermal_sensor *sensor = dev_get_drvdata(dev);
281 
282 	return st_thermal_sensor_off(sensor);
283 }
284 
st_thermal_resume(struct device * dev)285 static int st_thermal_resume(struct device *dev)
286 {
287 	int ret;
288 	struct st_thermal_sensor *sensor = dev_get_drvdata(dev);
289 
290 	ret = st_thermal_sensor_on(sensor);
291 	if (ret)
292 		return ret;
293 
294 	ret = st_thermal_calibration(sensor);
295 	if (ret)
296 		return ret;
297 
298 	if (sensor->ops->enable_irq) {
299 		ret = sensor->ops->enable_irq(sensor);
300 		if (ret)
301 			return ret;
302 	}
303 
304 	return 0;
305 }
306 #endif
307 
308 SIMPLE_DEV_PM_OPS(st_thermal_pm_ops, st_thermal_suspend, st_thermal_resume);
309 EXPORT_SYMBOL_GPL(st_thermal_pm_ops);
310 
311 MODULE_AUTHOR("STMicroelectronics (R&D) Limited <ajitpal.singh@st.com>");
312 MODULE_DESCRIPTION("STMicroelectronics STi SoC Thermal Sensor Driver");
313 MODULE_LICENSE("GPL v2");
314