2 * ST Thermal Sensor Driver core routines
3 * Author: Ajit Pal Singh <ajitpal.singh@st.com>
5 * Copyright (C) 2003-2014 STMicroelectronics (R&D) Limited
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.
14 #include <linux/clk.h>
15 #include <linux/module.h>
17 #include <linux/of_device.h>
19 #include "st_thermal.h"
21 /* The Thermal Framework expects millidegrees */
22 #define mcelsius(temp) ((temp) * 1000)
25 * Function to allocate regfields which are common
26 * between syscfg and memory mapped based sensors
28 static int st_thermal_alloc_regfields(struct st_thermal_sensor *sensor)
30 struct device *dev = sensor->dev;
31 struct regmap *regmap = sensor->regmap;
32 const struct reg_field *reg_fields = sensor->cdata->reg_fields;
34 sensor->dcorrect = devm_regmap_field_alloc(dev, regmap,
35 reg_fields[DCORRECT]);
37 sensor->overflow = devm_regmap_field_alloc(dev, regmap,
38 reg_fields[OVERFLOW]);
40 sensor->temp_data = devm_regmap_field_alloc(dev, regmap,
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");
50 return sensor->ops->alloc_regfields(sensor);
53 static int st_thermal_sensor_on(struct st_thermal_sensor *sensor)
56 struct device *dev = sensor->dev;
58 ret = clk_prepare_enable(sensor->clk);
60 dev_err(dev, "failed to enable clk\n");
64 ret = sensor->ops->power_ctrl(sensor, POWER_ON);
66 dev_err(dev, "failed to power on sensor\n");
67 clk_disable_unprepare(sensor->clk);
73 static int st_thermal_sensor_off(struct st_thermal_sensor *sensor)
77 ret = sensor->ops->power_ctrl(sensor, POWER_OFF);
81 clk_disable_unprepare(sensor->clk);
86 static int st_thermal_calibration(struct st_thermal_sensor *sensor)
90 struct device *dev = sensor->dev;
92 /* Check if sensor calibration data is already written */
93 ret = regmap_field_read(sensor->dcorrect, &val);
95 dev_err(dev, "failed to read calibration data\n");
101 * Sensor calibration value not set by bootloader,
102 * default calibration data to be used
104 ret = regmap_field_write(sensor->dcorrect,
105 sensor->cdata->calibration_val);
107 dev_err(dev, "failed to set calibration data\n");
113 /* Callback to get temperature from HW*/
114 static int st_thermal_get_temp(struct thermal_zone_device *th,
115 unsigned long *temperature)
117 struct st_thermal_sensor *sensor = th->devdata;
118 struct device *dev = sensor->dev;
120 unsigned int overflow;
123 ret = regmap_field_read(sensor->overflow, &overflow);
129 ret = regmap_field_read(sensor->temp_data, &temp);
133 temp += sensor->cdata->temp_adjust_val;
134 temp = mcelsius(temp);
136 dev_dbg(dev, "temperature: %d\n", temp);
143 static int st_thermal_get_trip_type(struct thermal_zone_device *th,
144 int trip, enum thermal_trip_type *type)
146 struct st_thermal_sensor *sensor = th->devdata;
147 struct device *dev = sensor->dev;
151 *type = THERMAL_TRIP_CRITICAL;
154 dev_err(dev, "invalid trip point\n");
161 static int st_thermal_get_trip_temp(struct thermal_zone_device *th,
162 int trip, unsigned long *temp)
164 struct st_thermal_sensor *sensor = th->devdata;
165 struct device *dev = sensor->dev;
169 *temp = mcelsius(sensor->cdata->crit_temp);
172 dev_err(dev, "Invalid trip point\n");
179 static 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,
185 int st_thermal_register(struct platform_device *pdev,
186 const struct of_device_id *st_thermal_of_match)
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;
197 dev_err(dev, "device tree node not found\n");
201 sensor = devm_kzalloc(dev, sizeof(*sensor), GFP_KERNEL);
207 match = of_match_device(st_thermal_of_match, dev);
208 if (!(match && match->data))
211 sensor->cdata = match->data;
212 if (!sensor->cdata->ops)
215 sensor->ops = sensor->cdata->ops;
217 ret = (sensor->ops->regmap_init)(sensor);
221 ret = st_thermal_alloc_regfields(sensor);
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);
231 if (sensor->ops->register_enable_irq) {
232 ret = sensor->ops->register_enable_irq(sensor);
237 ret = st_thermal_sensor_on(sensor);
241 ret = st_thermal_calibration(sensor);
245 polling_delay = sensor->ops->register_enable_irq ? 0 : 1000;
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);
256 platform_set_drvdata(pdev, sensor);
261 st_thermal_sensor_off(sensor);
265 EXPORT_SYMBOL_GPL(st_thermal_register);
267 int st_thermal_unregister(struct platform_device *pdev)
269 struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);
271 st_thermal_sensor_off(sensor);
272 thermal_zone_device_unregister(sensor->thermal_dev);
276 EXPORT_SYMBOL_GPL(st_thermal_unregister);
278 #ifdef CONFIG_PM_SLEEP
279 static int st_thermal_suspend(struct device *dev)
281 struct platform_device *pdev = to_platform_device(dev);
282 struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);
284 return st_thermal_sensor_off(sensor);
287 static int st_thermal_resume(struct device *dev)
290 struct platform_device *pdev = to_platform_device(dev);
291 struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);
293 ret = st_thermal_sensor_on(sensor);
297 ret = st_thermal_calibration(sensor);
301 if (sensor->ops->enable_irq) {
302 ret = sensor->ops->enable_irq(sensor);
311 SIMPLE_DEV_PM_OPS(st_thermal_pm_ops, st_thermal_suspend, st_thermal_resume);
312 EXPORT_SYMBOL_GPL(st_thermal_pm_ops);
314 MODULE_AUTHOR("STMicroelectronics (R&D) Limited <ajitpal.singh@st.com>");
315 MODULE_DESCRIPTION("STMicroelectronics STi SoC Thermal Sensor Driver");
316 MODULE_LICENSE("GPL v2");