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