1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * db8500_thermal.c - DB8500 Thermal Management Implementation
4 *
5 * Copyright (C) 2012 ST-Ericsson
6 * Copyright (C) 2012-2019 Linaro Ltd.
7 *
8 * Authors: Hongbo Zhang, Linus Walleij
9 */
10
11 #include <linux/cpu_cooling.h>
12 #include <linux/interrupt.h>
13 #include <linux/mfd/dbx500-prcmu.h>
14 #include <linux/module.h>
15 #include <linux/of.h>
16 #include <linux/platform_device.h>
17 #include <linux/slab.h>
18 #include <linux/thermal.h>
19
20 #define PRCMU_DEFAULT_MEASURE_TIME 0xFFF
21 #define PRCMU_DEFAULT_LOW_TEMP 0
22
23 /**
24 * db8500_thermal_points - the interpolation points that trigger
25 * interrupts
26 */
27 static const unsigned long db8500_thermal_points[] = {
28 15000,
29 20000,
30 25000,
31 30000,
32 35000,
33 40000,
34 45000,
35 50000,
36 55000,
37 60000,
38 65000,
39 70000,
40 75000,
41 80000,
42 /*
43 * This is where things start to get really bad for the
44 * SoC and the thermal zones should be set up to trigger
45 * critical temperature at 85000 mC so we don't get above
46 * this point.
47 */
48 85000,
49 90000,
50 95000,
51 100000,
52 };
53
54 struct db8500_thermal_zone {
55 struct thermal_zone_device *tz;
56 unsigned long interpolated_temp;
57 unsigned int cur_index;
58 };
59
60 /* Callback to get current temperature */
db8500_thermal_get_temp(struct thermal_zone_device * tz,int * temp)61 static int db8500_thermal_get_temp(struct thermal_zone_device *tz, int *temp)
62 {
63 struct db8500_thermal_zone *th = tz->devdata;
64
65 /*
66 * TODO: There is no PRCMU interface to get temperature data currently,
67 * so a pseudo temperature is returned , it works for thermal framework
68 * and this will be fixed when the PRCMU interface is available.
69 */
70 *temp = th->interpolated_temp;
71
72 return 0;
73 }
74
75 static const struct thermal_zone_device_ops thdev_ops = {
76 .get_temp = db8500_thermal_get_temp,
77 };
78
db8500_thermal_update_config(struct db8500_thermal_zone * th,unsigned int idx,unsigned long next_low,unsigned long next_high)79 static void db8500_thermal_update_config(struct db8500_thermal_zone *th,
80 unsigned int idx,
81 unsigned long next_low,
82 unsigned long next_high)
83 {
84 prcmu_stop_temp_sense();
85
86 th->cur_index = idx;
87 th->interpolated_temp = (next_low + next_high)/2;
88
89 /*
90 * The PRCMU accept absolute temperatures in celsius so divide
91 * down the millicelsius with 1000
92 */
93 prcmu_config_hotmon((u8)(next_low/1000), (u8)(next_high/1000));
94 prcmu_start_temp_sense(PRCMU_DEFAULT_MEASURE_TIME);
95 }
96
prcmu_low_irq_handler(int irq,void * irq_data)97 static irqreturn_t prcmu_low_irq_handler(int irq, void *irq_data)
98 {
99 struct db8500_thermal_zone *th = irq_data;
100 unsigned int idx = th->cur_index;
101 unsigned long next_low, next_high;
102
103 if (idx == 0)
104 /* Meaningless for thermal management, ignoring it */
105 return IRQ_HANDLED;
106
107 if (idx == 1) {
108 next_high = db8500_thermal_points[0];
109 next_low = PRCMU_DEFAULT_LOW_TEMP;
110 } else {
111 next_high = db8500_thermal_points[idx - 1];
112 next_low = db8500_thermal_points[idx - 2];
113 }
114 idx -= 1;
115
116 db8500_thermal_update_config(th, idx, next_low, next_high);
117 dev_dbg(&th->tz->device,
118 "PRCMU set max %ld, min %ld\n", next_high, next_low);
119
120 thermal_zone_device_update(th->tz, THERMAL_EVENT_UNSPECIFIED);
121
122 return IRQ_HANDLED;
123 }
124
prcmu_high_irq_handler(int irq,void * irq_data)125 static irqreturn_t prcmu_high_irq_handler(int irq, void *irq_data)
126 {
127 struct db8500_thermal_zone *th = irq_data;
128 unsigned int idx = th->cur_index;
129 unsigned long next_low, next_high;
130 int num_points = ARRAY_SIZE(db8500_thermal_points);
131
132 if (idx < num_points - 1) {
133 next_high = db8500_thermal_points[idx+1];
134 next_low = db8500_thermal_points[idx];
135 idx += 1;
136
137 db8500_thermal_update_config(th, idx, next_low, next_high);
138
139 dev_dbg(&th->tz->device,
140 "PRCMU set max %ld, min %ld\n", next_high, next_low);
141 } else if (idx == num_points - 1)
142 /* So we roof out 1 degree over the max point */
143 th->interpolated_temp = db8500_thermal_points[idx] + 1;
144
145 thermal_zone_device_update(th->tz, THERMAL_EVENT_UNSPECIFIED);
146
147 return IRQ_HANDLED;
148 }
149
db8500_thermal_probe(struct platform_device * pdev)150 static int db8500_thermal_probe(struct platform_device *pdev)
151 {
152 struct db8500_thermal_zone *th = NULL;
153 struct device *dev = &pdev->dev;
154 int low_irq, high_irq, ret = 0;
155
156 th = devm_kzalloc(dev, sizeof(*th), GFP_KERNEL);
157 if (!th)
158 return -ENOMEM;
159
160 low_irq = platform_get_irq_byname(pdev, "IRQ_HOTMON_LOW");
161 if (low_irq < 0)
162 return low_irq;
163
164 ret = devm_request_threaded_irq(dev, low_irq, NULL,
165 prcmu_low_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT,
166 "dbx500_temp_low", th);
167 if (ret < 0) {
168 dev_err(dev, "failed to allocate temp low irq\n");
169 return ret;
170 }
171
172 high_irq = platform_get_irq_byname(pdev, "IRQ_HOTMON_HIGH");
173 if (high_irq < 0)
174 return high_irq;
175
176 ret = devm_request_threaded_irq(dev, high_irq, NULL,
177 prcmu_high_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT,
178 "dbx500_temp_high", th);
179 if (ret < 0) {
180 dev_err(dev, "failed to allocate temp high irq\n");
181 return ret;
182 }
183
184 /* register of thermal sensor and get info from DT */
185 th->tz = devm_thermal_of_zone_register(dev, 0, th, &thdev_ops);
186 if (IS_ERR(th->tz)) {
187 dev_err(dev, "register thermal zone sensor failed\n");
188 return PTR_ERR(th->tz);
189 }
190 dev_info(dev, "thermal zone sensor registered\n");
191
192 /* Start measuring at the lowest point */
193 db8500_thermal_update_config(th, 0, PRCMU_DEFAULT_LOW_TEMP,
194 db8500_thermal_points[0]);
195
196 platform_set_drvdata(pdev, th);
197
198 return 0;
199 }
200
db8500_thermal_suspend(struct platform_device * pdev,pm_message_t state)201 static int db8500_thermal_suspend(struct platform_device *pdev,
202 pm_message_t state)
203 {
204 prcmu_stop_temp_sense();
205
206 return 0;
207 }
208
db8500_thermal_resume(struct platform_device * pdev)209 static int db8500_thermal_resume(struct platform_device *pdev)
210 {
211 struct db8500_thermal_zone *th = platform_get_drvdata(pdev);
212
213 /* Resume and start measuring at the lowest point */
214 db8500_thermal_update_config(th, 0, PRCMU_DEFAULT_LOW_TEMP,
215 db8500_thermal_points[0]);
216
217 return 0;
218 }
219
220 static const struct of_device_id db8500_thermal_match[] = {
221 { .compatible = "stericsson,db8500-thermal" },
222 {},
223 };
224 MODULE_DEVICE_TABLE(of, db8500_thermal_match);
225
226 static struct platform_driver db8500_thermal_driver = {
227 .driver = {
228 .name = "db8500-thermal",
229 .of_match_table = of_match_ptr(db8500_thermal_match),
230 },
231 .probe = db8500_thermal_probe,
232 .suspend = db8500_thermal_suspend,
233 .resume = db8500_thermal_resume,
234 };
235
236 module_platform_driver(db8500_thermal_driver);
237
238 MODULE_AUTHOR("Hongbo Zhang <hongbo.zhang@stericsson.com>");
239 MODULE_DESCRIPTION("DB8500 thermal driver");
240 MODULE_LICENSE("GPL");
241