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