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 = thermal_zone_device_priv(th);
112 unsigned int temp;
113 unsigned int overflow;
114 int ret;
115
116 ret = regmap_field_read(sensor->overflow, &overflow);
117 if (ret)
118 return ret;
119 if (overflow)
120 return -EIO;
121
122 ret = regmap_field_read(sensor->temp_data, &temp);
123 if (ret)
124 return ret;
125
126 temp += sensor->cdata->temp_adjust_val;
127 temp = mcelsius(temp);
128
129 *temperature = temp;
130
131 return 0;
132 }
133
134 static struct thermal_zone_device_ops st_tz_ops = {
135 .get_temp = st_thermal_get_temp,
136 };
137
138 static struct thermal_trip trip;
139
st_thermal_register(struct platform_device * pdev,const struct of_device_id * st_thermal_of_match)140 int st_thermal_register(struct platform_device *pdev,
141 const struct of_device_id *st_thermal_of_match)
142 {
143 struct st_thermal_sensor *sensor;
144 struct device *dev = &pdev->dev;
145 struct device_node *np = dev->of_node;
146 const struct of_device_id *match;
147
148 int polling_delay;
149 int ret;
150
151 if (!np) {
152 dev_err(dev, "device tree node not found\n");
153 return -EINVAL;
154 }
155
156 sensor = devm_kzalloc(dev, sizeof(*sensor), GFP_KERNEL);
157 if (!sensor)
158 return -ENOMEM;
159
160 sensor->dev = dev;
161
162 match = of_match_device(st_thermal_of_match, dev);
163 if (!(match && match->data))
164 return -EINVAL;
165
166 sensor->cdata = match->data;
167 if (!sensor->cdata->ops)
168 return -EINVAL;
169
170 sensor->ops = sensor->cdata->ops;
171
172 ret = (sensor->ops->regmap_init)(sensor);
173 if (ret)
174 return ret;
175
176 ret = st_thermal_alloc_regfields(sensor);
177 if (ret)
178 return ret;
179
180 sensor->clk = devm_clk_get(dev, "thermal");
181 if (IS_ERR(sensor->clk)) {
182 dev_err(dev, "failed to fetch clock\n");
183 return PTR_ERR(sensor->clk);
184 }
185
186 if (sensor->ops->register_enable_irq) {
187 ret = sensor->ops->register_enable_irq(sensor);
188 if (ret)
189 return ret;
190 }
191
192 ret = st_thermal_sensor_on(sensor);
193 if (ret)
194 return ret;
195
196 ret = st_thermal_calibration(sensor);
197 if (ret)
198 goto sensor_off;
199
200 polling_delay = sensor->ops->register_enable_irq ? 0 : 1000;
201
202 trip.temperature = sensor->cdata->crit_temp;
203 trip.type = THERMAL_TRIP_CRITICAL;
204
205 sensor->thermal_dev =
206 thermal_zone_device_register_with_trips(dev_name(dev), &trip, 1, sensor,
207 &st_tz_ops, NULL, 0, polling_delay);
208 if (IS_ERR(sensor->thermal_dev)) {
209 dev_err(dev, "failed to register thermal zone device\n");
210 ret = PTR_ERR(sensor->thermal_dev);
211 goto sensor_off;
212 }
213 ret = thermal_zone_device_enable(sensor->thermal_dev);
214 if (ret)
215 goto tzd_unregister;
216
217 platform_set_drvdata(pdev, sensor);
218
219 return 0;
220
221 tzd_unregister:
222 thermal_zone_device_unregister(sensor->thermal_dev);
223 sensor_off:
224 st_thermal_sensor_off(sensor);
225
226 return ret;
227 }
228 EXPORT_SYMBOL_GPL(st_thermal_register);
229
st_thermal_unregister(struct platform_device * pdev)230 void st_thermal_unregister(struct platform_device *pdev)
231 {
232 struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);
233
234 st_thermal_sensor_off(sensor);
235 thermal_zone_device_unregister(sensor->thermal_dev);
236 }
237 EXPORT_SYMBOL_GPL(st_thermal_unregister);
238
239 #ifdef CONFIG_PM_SLEEP
st_thermal_suspend(struct device * dev)240 static int st_thermal_suspend(struct device *dev)
241 {
242 struct st_thermal_sensor *sensor = dev_get_drvdata(dev);
243
244 return st_thermal_sensor_off(sensor);
245 }
246
st_thermal_resume(struct device * dev)247 static int st_thermal_resume(struct device *dev)
248 {
249 int ret;
250 struct st_thermal_sensor *sensor = dev_get_drvdata(dev);
251
252 ret = st_thermal_sensor_on(sensor);
253 if (ret)
254 return ret;
255
256 ret = st_thermal_calibration(sensor);
257 if (ret)
258 return ret;
259
260 if (sensor->ops->enable_irq) {
261 ret = sensor->ops->enable_irq(sensor);
262 if (ret)
263 return ret;
264 }
265
266 return 0;
267 }
268 #endif
269
270 SIMPLE_DEV_PM_OPS(st_thermal_pm_ops, st_thermal_suspend, st_thermal_resume);
271 EXPORT_SYMBOL_GPL(st_thermal_pm_ops);
272
273 MODULE_AUTHOR("STMicroelectronics (R&D) Limited <ajitpal.singh@st.com>");
274 MODULE_DESCRIPTION("STMicroelectronics STi SoC Thermal Sensor Driver");
275 MODULE_LICENSE("GPL v2");
276