1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * OMAP thermal driver interface
4  *
5  * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
6  * Contact:
7  *   Eduardo Valentin <eduardo.valentin@ti.com>
8  */
9 
10 #include <linux/device.h>
11 #include <linux/err.h>
12 #include <linux/mutex.h>
13 #include <linux/gfp.h>
14 #include <linux/kernel.h>
15 #include <linux/workqueue.h>
16 #include <linux/thermal.h>
17 #include <linux/cpufreq.h>
18 #include <linux/cpumask.h>
19 #include <linux/cpu_cooling.h>
20 #include <linux/of.h>
21 
22 #include "ti-thermal.h"
23 #include "ti-bandgap.h"
24 #include "../thermal_hwmon.h"
25 
26 #define TI_BANDGAP_UPDATE_INTERVAL_MS 250
27 
28 /* common data structures */
29 struct ti_thermal_data {
30 	struct cpufreq_policy *policy;
31 	struct thermal_zone_device *ti_thermal;
32 	struct thermal_zone_device *pcb_tz;
33 	struct thermal_cooling_device *cool_dev;
34 	struct ti_bandgap *bgp;
35 	enum thermal_device_mode mode;
36 	struct work_struct thermal_wq;
37 	int sensor_id;
38 	bool our_zone;
39 };
40 
ti_thermal_work(struct work_struct * work)41 static void ti_thermal_work(struct work_struct *work)
42 {
43 	struct ti_thermal_data *data = container_of(work,
44 					struct ti_thermal_data, thermal_wq);
45 
46 	thermal_zone_device_update(data->ti_thermal, THERMAL_EVENT_UNSPECIFIED);
47 
48 	dev_dbg(data->bgp->dev, "updated thermal zone %s\n",
49 		thermal_zone_device_type(data->ti_thermal));
50 }
51 
52 /**
53  * ti_thermal_hotspot_temperature - returns sensor extrapolated temperature
54  * @t:	omap sensor temperature
55  * @s:	omap sensor slope value
56  * @c:	omap sensor const value
57  */
ti_thermal_hotspot_temperature(int t,int s,int c)58 static inline int ti_thermal_hotspot_temperature(int t, int s, int c)
59 {
60 	int delta = t * s / 1000 + c;
61 
62 	if (delta < 0)
63 		delta = 0;
64 
65 	return t + delta;
66 }
67 
68 /* thermal zone ops */
69 /* Get temperature callback function for thermal zone */
__ti_thermal_get_temp(struct thermal_zone_device * tz,int * temp)70 static inline int __ti_thermal_get_temp(struct thermal_zone_device *tz, int *temp)
71 {
72 	struct thermal_zone_device *pcb_tz = NULL;
73 	struct ti_thermal_data *data = thermal_zone_device_priv(tz);
74 	struct ti_bandgap *bgp;
75 	const struct ti_temp_sensor *s;
76 	int ret, tmp, slope, constant;
77 	int pcb_temp;
78 
79 	if (!data)
80 		return 0;
81 
82 	bgp = data->bgp;
83 	s = &bgp->conf->sensors[data->sensor_id];
84 
85 	ret = ti_bandgap_read_temperature(bgp, data->sensor_id, &tmp);
86 	if (ret)
87 		return ret;
88 
89 	/* Default constants */
90 	slope = thermal_zone_get_slope(tz);
91 	constant = thermal_zone_get_offset(tz);
92 
93 	pcb_tz = data->pcb_tz;
94 	/* In case pcb zone is available, use the extrapolation rule with it */
95 	if (!IS_ERR(pcb_tz)) {
96 		ret = thermal_zone_get_temp(pcb_tz, &pcb_temp);
97 		if (!ret) {
98 			tmp -= pcb_temp; /* got a valid PCB temp */
99 			slope = s->slope_pcb;
100 			constant = s->constant_pcb;
101 		} else {
102 			dev_err(bgp->dev,
103 				"Failed to read PCB state. Using defaults\n");
104 			ret = 0;
105 		}
106 	}
107 	*temp = ti_thermal_hotspot_temperature(tmp, slope, constant);
108 
109 	return ret;
110 }
111 
__ti_thermal_get_trend(struct thermal_zone_device * tz,const struct thermal_trip * trip,enum thermal_trend * trend)112 static int __ti_thermal_get_trend(struct thermal_zone_device *tz,
113 				  const struct thermal_trip *trip,
114 				  enum thermal_trend *trend)
115 {
116 	struct ti_thermal_data *data = thermal_zone_device_priv(tz);
117 	struct ti_bandgap *bgp;
118 	int id, tr, ret = 0;
119 
120 	bgp = data->bgp;
121 	id = data->sensor_id;
122 
123 	ret = ti_bandgap_get_trend(bgp, id, &tr);
124 	if (ret)
125 		return ret;
126 
127 	if (tr > 0)
128 		*trend = THERMAL_TREND_RAISING;
129 	else if (tr < 0)
130 		*trend = THERMAL_TREND_DROPPING;
131 	else
132 		*trend = THERMAL_TREND_STABLE;
133 
134 	return 0;
135 }
136 
137 static const struct thermal_zone_device_ops ti_of_thermal_ops = {
138 	.get_temp = __ti_thermal_get_temp,
139 	.get_trend = __ti_thermal_get_trend,
140 };
141 
142 static struct ti_thermal_data
ti_thermal_build_data(struct ti_bandgap * bgp,int id)143 *ti_thermal_build_data(struct ti_bandgap *bgp, int id)
144 {
145 	struct ti_thermal_data *data;
146 
147 	data = devm_kzalloc(bgp->dev, sizeof(*data), GFP_KERNEL);
148 	if (!data) {
149 		dev_err(bgp->dev, "kzalloc fail\n");
150 		return NULL;
151 	}
152 	data->sensor_id = id;
153 	data->bgp = bgp;
154 	data->mode = THERMAL_DEVICE_ENABLED;
155 	/* pcb_tz will be either valid or PTR_ERR() */
156 	data->pcb_tz = thermal_zone_get_zone_by_name("pcb");
157 	INIT_WORK(&data->thermal_wq, ti_thermal_work);
158 
159 	return data;
160 }
161 
ti_thermal_expose_sensor(struct ti_bandgap * bgp,int id,char * domain)162 int ti_thermal_expose_sensor(struct ti_bandgap *bgp, int id,
163 			     char *domain)
164 {
165 	struct ti_thermal_data *data;
166 
167 	data = ti_bandgap_get_sensor_data(bgp, id);
168 
169 	if (IS_ERR_OR_NULL(data))
170 		data = ti_thermal_build_data(bgp, id);
171 
172 	if (!data)
173 		return -EINVAL;
174 
175 	/* in case this is specified by DT */
176 	data->ti_thermal = devm_thermal_of_zone_register(bgp->dev, id,
177 					data, &ti_of_thermal_ops);
178 	if (IS_ERR(data->ti_thermal)) {
179 		dev_err(bgp->dev, "thermal zone device is NULL\n");
180 		return PTR_ERR(data->ti_thermal);
181 	}
182 
183 	ti_bandgap_set_sensor_data(bgp, id, data);
184 	ti_bandgap_write_update_interval(bgp, data->sensor_id,
185 					 TI_BANDGAP_UPDATE_INTERVAL_MS);
186 
187 	devm_thermal_add_hwmon_sysfs(bgp->dev, data->ti_thermal);
188 
189 	return 0;
190 }
191 
ti_thermal_remove_sensor(struct ti_bandgap * bgp,int id)192 int ti_thermal_remove_sensor(struct ti_bandgap *bgp, int id)
193 {
194 	struct ti_thermal_data *data;
195 
196 	data = ti_bandgap_get_sensor_data(bgp, id);
197 
198 	if (!IS_ERR_OR_NULL(data) && data->ti_thermal) {
199 		if (data->our_zone)
200 			thermal_zone_device_unregister(data->ti_thermal);
201 	}
202 
203 	return 0;
204 }
205 
ti_thermal_report_sensor_temperature(struct ti_bandgap * bgp,int id)206 int ti_thermal_report_sensor_temperature(struct ti_bandgap *bgp, int id)
207 {
208 	struct ti_thermal_data *data;
209 
210 	data = ti_bandgap_get_sensor_data(bgp, id);
211 
212 	schedule_work(&data->thermal_wq);
213 
214 	return 0;
215 }
216 
ti_thermal_register_cpu_cooling(struct ti_bandgap * bgp,int id)217 int ti_thermal_register_cpu_cooling(struct ti_bandgap *bgp, int id)
218 {
219 	struct ti_thermal_data *data;
220 	struct device_node *np = bgp->dev->of_node;
221 
222 	/*
223 	 * We are assuming here that if one deploys the zone
224 	 * using DT, then it must be aware that the cooling device
225 	 * loading has to happen via cpufreq driver.
226 	 */
227 	if (of_property_present(np, "#thermal-sensor-cells"))
228 		return 0;
229 
230 	data = ti_bandgap_get_sensor_data(bgp, id);
231 	if (!data || IS_ERR(data))
232 		data = ti_thermal_build_data(bgp, id);
233 
234 	if (!data)
235 		return -EINVAL;
236 
237 	data->policy = cpufreq_cpu_get(0);
238 	if (!data->policy) {
239 		pr_debug("%s: CPUFreq policy not found\n", __func__);
240 		return -EPROBE_DEFER;
241 	}
242 
243 	/* Register cooling device */
244 	data->cool_dev = cpufreq_cooling_register(data->policy);
245 	if (IS_ERR(data->cool_dev)) {
246 		int ret = PTR_ERR(data->cool_dev);
247 		dev_err(bgp->dev, "Failed to register cpu cooling device %d\n",
248 			ret);
249 		cpufreq_cpu_put(data->policy);
250 
251 		return ret;
252 	}
253 	ti_bandgap_set_sensor_data(bgp, id, data);
254 
255 	return 0;
256 }
257 
ti_thermal_unregister_cpu_cooling(struct ti_bandgap * bgp,int id)258 int ti_thermal_unregister_cpu_cooling(struct ti_bandgap *bgp, int id)
259 {
260 	struct ti_thermal_data *data;
261 
262 	data = ti_bandgap_get_sensor_data(bgp, id);
263 
264 	if (!IS_ERR_OR_NULL(data)) {
265 		cpufreq_cooling_unregister(data->cool_dev);
266 		if (data->policy)
267 			cpufreq_cpu_put(data->policy);
268 	}
269 
270 	return 0;
271 }
272