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