xref: /openbmc/linux/drivers/thermal/st/st_thermal.c (revision 2ef95331)
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, 0, 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