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
25 /* common data structures */
26 struct ti_thermal_data {
27 struct cpufreq_policy *policy;
28 struct thermal_zone_device *ti_thermal;
29 struct thermal_zone_device *pcb_tz;
30 struct thermal_cooling_device *cool_dev;
31 struct ti_bandgap *bgp;
32 enum thermal_device_mode mode;
33 struct work_struct thermal_wq;
34 int sensor_id;
35 bool our_zone;
36 };
37
ti_thermal_work(struct work_struct * work)38 static void ti_thermal_work(struct work_struct *work)
39 {
40 struct ti_thermal_data *data = container_of(work,
41 struct ti_thermal_data, thermal_wq);
42
43 thermal_zone_device_update(data->ti_thermal, THERMAL_EVENT_UNSPECIFIED);
44
45 dev_dbg(&data->ti_thermal->device, "updated thermal zone %s\n",
46 data->ti_thermal->type);
47 }
48
49 /**
50 * ti_thermal_hotspot_temperature - returns sensor extrapolated temperature
51 * @t: omap sensor temperature
52 * @s: omap sensor slope value
53 * @c: omap sensor const value
54 */
ti_thermal_hotspot_temperature(int t,int s,int c)55 static inline int ti_thermal_hotspot_temperature(int t, int s, int c)
56 {
57 int delta = t * s / 1000 + c;
58
59 if (delta < 0)
60 delta = 0;
61
62 return t + delta;
63 }
64
65 /* thermal zone ops */
66 /* Get temperature callback function for thermal zone */
__ti_thermal_get_temp(void * devdata,int * temp)67 static inline int __ti_thermal_get_temp(void *devdata, int *temp)
68 {
69 struct thermal_zone_device *pcb_tz = NULL;
70 struct ti_thermal_data *data = devdata;
71 struct ti_bandgap *bgp;
72 const struct ti_temp_sensor *s;
73 int ret, tmp, slope, constant;
74 int pcb_temp;
75
76 if (!data)
77 return 0;
78
79 bgp = data->bgp;
80 s = &bgp->conf->sensors[data->sensor_id];
81
82 ret = ti_bandgap_read_temperature(bgp, data->sensor_id, &tmp);
83 if (ret)
84 return ret;
85
86 /* Default constants */
87 slope = thermal_zone_get_slope(data->ti_thermal);
88 constant = thermal_zone_get_offset(data->ti_thermal);
89
90 pcb_tz = data->pcb_tz;
91 /* In case pcb zone is available, use the extrapolation rule with it */
92 if (!IS_ERR(pcb_tz)) {
93 ret = thermal_zone_get_temp(pcb_tz, &pcb_temp);
94 if (!ret) {
95 tmp -= pcb_temp; /* got a valid PCB temp */
96 slope = s->slope_pcb;
97 constant = s->constant_pcb;
98 } else {
99 dev_err(bgp->dev,
100 "Failed to read PCB state. Using defaults\n");
101 ret = 0;
102 }
103 }
104 *temp = ti_thermal_hotspot_temperature(tmp, slope, constant);
105
106 return ret;
107 }
108
ti_thermal_get_temp(struct thermal_zone_device * thermal,int * temp)109 static inline int ti_thermal_get_temp(struct thermal_zone_device *thermal,
110 int *temp)
111 {
112 struct ti_thermal_data *data = thermal->devdata;
113
114 return __ti_thermal_get_temp(data, temp);
115 }
116
__ti_thermal_get_trend(void * p,int trip,enum thermal_trend * trend)117 static int __ti_thermal_get_trend(void *p, int trip, enum thermal_trend *trend)
118 {
119 struct ti_thermal_data *data = p;
120 struct ti_bandgap *bgp;
121 int id, tr, ret = 0;
122
123 bgp = data->bgp;
124 id = data->sensor_id;
125
126 ret = ti_bandgap_get_trend(bgp, id, &tr);
127 if (ret)
128 return ret;
129
130 if (tr > 0)
131 *trend = THERMAL_TREND_RAISING;
132 else if (tr < 0)
133 *trend = THERMAL_TREND_DROPPING;
134 else
135 *trend = THERMAL_TREND_STABLE;
136
137 return 0;
138 }
139
140 static const struct thermal_zone_of_device_ops ti_of_thermal_ops = {
141 .get_temp = __ti_thermal_get_temp,
142 .get_trend = __ti_thermal_get_trend,
143 };
144
145 static struct ti_thermal_data
ti_thermal_build_data(struct ti_bandgap * bgp,int id)146 *ti_thermal_build_data(struct ti_bandgap *bgp, int id)
147 {
148 struct ti_thermal_data *data;
149
150 data = devm_kzalloc(bgp->dev, sizeof(*data), GFP_KERNEL);
151 if (!data) {
152 dev_err(bgp->dev, "kzalloc fail\n");
153 return NULL;
154 }
155 data->sensor_id = id;
156 data->bgp = bgp;
157 data->mode = THERMAL_DEVICE_ENABLED;
158 /* pcb_tz will be either valid or PTR_ERR() */
159 data->pcb_tz = thermal_zone_get_zone_by_name("pcb");
160 INIT_WORK(&data->thermal_wq, ti_thermal_work);
161
162 return data;
163 }
164
ti_thermal_expose_sensor(struct ti_bandgap * bgp,int id,char * domain)165 int ti_thermal_expose_sensor(struct ti_bandgap *bgp, int id,
166 char *domain)
167 {
168 struct ti_thermal_data *data;
169 int interval;
170
171 data = ti_bandgap_get_sensor_data(bgp, id);
172
173 if (IS_ERR_OR_NULL(data))
174 data = ti_thermal_build_data(bgp, id);
175
176 if (!data)
177 return -EINVAL;
178
179 /* in case this is specified by DT */
180 data->ti_thermal = devm_thermal_zone_of_sensor_register(bgp->dev, id,
181 data, &ti_of_thermal_ops);
182 if (IS_ERR(data->ti_thermal)) {
183 dev_err(bgp->dev, "thermal zone device is NULL\n");
184 return PTR_ERR(data->ti_thermal);
185 }
186
187 interval = jiffies_to_msecs(data->ti_thermal->polling_delay_jiffies);
188
189 ti_bandgap_set_sensor_data(bgp, id, data);
190 ti_bandgap_write_update_interval(bgp, data->sensor_id, interval);
191
192 return 0;
193 }
194
ti_thermal_remove_sensor(struct ti_bandgap * bgp,int id)195 int ti_thermal_remove_sensor(struct ti_bandgap *bgp, int id)
196 {
197 struct ti_thermal_data *data;
198
199 data = ti_bandgap_get_sensor_data(bgp, id);
200
201 if (!IS_ERR_OR_NULL(data) && data->ti_thermal) {
202 if (data->our_zone)
203 thermal_zone_device_unregister(data->ti_thermal);
204 }
205
206 return 0;
207 }
208
ti_thermal_report_sensor_temperature(struct ti_bandgap * bgp,int id)209 int ti_thermal_report_sensor_temperature(struct ti_bandgap *bgp, int id)
210 {
211 struct ti_thermal_data *data;
212
213 data = ti_bandgap_get_sensor_data(bgp, id);
214
215 schedule_work(&data->thermal_wq);
216
217 return 0;
218 }
219
ti_thermal_register_cpu_cooling(struct ti_bandgap * bgp,int id)220 int ti_thermal_register_cpu_cooling(struct ti_bandgap *bgp, int id)
221 {
222 struct ti_thermal_data *data;
223 struct device_node *np = bgp->dev->of_node;
224
225 /*
226 * We are assuming here that if one deploys the zone
227 * using DT, then it must be aware that the cooling device
228 * loading has to happen via cpufreq driver.
229 */
230 if (of_find_property(np, "#thermal-sensor-cells", NULL))
231 return 0;
232
233 data = ti_bandgap_get_sensor_data(bgp, id);
234 if (!data || IS_ERR(data))
235 data = ti_thermal_build_data(bgp, id);
236
237 if (!data)
238 return -EINVAL;
239
240 data->policy = cpufreq_cpu_get(0);
241 if (!data->policy) {
242 pr_debug("%s: CPUFreq policy not found\n", __func__);
243 return -EPROBE_DEFER;
244 }
245
246 /* Register cooling device */
247 data->cool_dev = cpufreq_cooling_register(data->policy);
248 if (IS_ERR(data->cool_dev)) {
249 int ret = PTR_ERR(data->cool_dev);
250 dev_err(bgp->dev, "Failed to register cpu cooling device %d\n",
251 ret);
252 cpufreq_cpu_put(data->policy);
253
254 return ret;
255 }
256 ti_bandgap_set_sensor_data(bgp, id, data);
257
258 return 0;
259 }
260
ti_thermal_unregister_cpu_cooling(struct ti_bandgap * bgp,int id)261 int ti_thermal_unregister_cpu_cooling(struct ti_bandgap *bgp, int id)
262 {
263 struct ti_thermal_data *data;
264
265 data = ti_bandgap_get_sensor_data(bgp, id);
266
267 if (!IS_ERR_OR_NULL(data)) {
268 cpufreq_cooling_unregister(data->cool_dev);
269 if (data->policy)
270 cpufreq_cpu_put(data->policy);
271 }
272
273 return 0;
274 }
275