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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 | struct device *dev; | |
57 | unsigned long interpolated_temp; | |
58 | unsigned int cur_index; | |
59 | }; | |
60 | ||
61 | /* Callback to get current temperature */ | |
62 | static int db8500_thermal_get_temp(struct thermal_zone_device *tz, int *temp) | |
63 | { | |
64 | struct db8500_thermal_zone *th = thermal_zone_device_priv(tz); | |
65 | ||
66 | /* | |
67 | * TODO: There is no PRCMU interface to get temperature data currently, | |
68 | * so a pseudo temperature is returned , it works for thermal framework | |
69 | * and this will be fixed when the PRCMU interface is available. | |
70 | */ | |
71 | *temp = th->interpolated_temp; | |
72 | ||
73 | return 0; | |
74 | } | |
75 | ||
76 | static const struct thermal_zone_device_ops thdev_ops = { | |
77 | .get_temp = db8500_thermal_get_temp, | |
78 | }; | |
79 | ||
80 | static void db8500_thermal_update_config(struct db8500_thermal_zone *th, | |
81 | unsigned int idx, | |
82 | unsigned long next_low, | |
83 | unsigned long next_high) | |
84 | { | |
85 | prcmu_stop_temp_sense(); | |
86 | ||
87 | th->cur_index = idx; | |
88 | th->interpolated_temp = (next_low + next_high)/2; | |
89 | ||
90 | /* | |
91 | * The PRCMU accept absolute temperatures in celsius so divide | |
92 | * down the millicelsius with 1000 | |
93 | */ | |
94 | prcmu_config_hotmon((u8)(next_low/1000), (u8)(next_high/1000)); | |
95 | prcmu_start_temp_sense(PRCMU_DEFAULT_MEASURE_TIME); | |
96 | } | |
97 | ||
98 | static irqreturn_t prcmu_low_irq_handler(int irq, void *irq_data) | |
99 | { | |
100 | struct db8500_thermal_zone *th = irq_data; | |
101 | unsigned int idx = th->cur_index; | |
102 | unsigned long next_low, next_high; | |
103 | ||
104 | if (idx == 0) | |
105 | /* Meaningless for thermal management, ignoring it */ | |
106 | return IRQ_HANDLED; | |
107 | ||
108 | if (idx == 1) { | |
109 | next_high = db8500_thermal_points[0]; | |
110 | next_low = PRCMU_DEFAULT_LOW_TEMP; | |
111 | } else { | |
112 | next_high = db8500_thermal_points[idx - 1]; | |
113 | next_low = db8500_thermal_points[idx - 2]; | |
114 | } | |
115 | idx -= 1; | |
116 | ||
117 | db8500_thermal_update_config(th, idx, next_low, next_high); | |
118 | dev_dbg(th->dev, | |
119 | "PRCMU set max %ld, min %ld\n", next_high, next_low); | |
120 | ||
121 | thermal_zone_device_update(th->tz, THERMAL_EVENT_UNSPECIFIED); | |
122 | ||
123 | return IRQ_HANDLED; | |
124 | } | |
125 | ||
126 | static irqreturn_t prcmu_high_irq_handler(int irq, void *irq_data) | |
127 | { | |
128 | struct db8500_thermal_zone *th = irq_data; | |
129 | unsigned int idx = th->cur_index; | |
130 | unsigned long next_low, next_high; | |
131 | int num_points = ARRAY_SIZE(db8500_thermal_points); | |
132 | ||
133 | if (idx < num_points - 1) { | |
134 | next_high = db8500_thermal_points[idx+1]; | |
135 | next_low = db8500_thermal_points[idx]; | |
136 | idx += 1; | |
137 | ||
138 | db8500_thermal_update_config(th, idx, next_low, next_high); | |
139 | ||
140 | dev_dbg(th->dev, | |
141 | "PRCMU set max %ld, min %ld\n", next_high, next_low); | |
142 | } else if (idx == num_points - 1) | |
143 | /* So we roof out 1 degree over the max point */ | |
144 | th->interpolated_temp = db8500_thermal_points[idx] + 1; | |
145 | ||
146 | thermal_zone_device_update(th->tz, THERMAL_EVENT_UNSPECIFIED); | |
147 | ||
148 | return IRQ_HANDLED; | |
149 | } | |
150 | ||
151 | static int db8500_thermal_probe(struct platform_device *pdev) | |
152 | { | |
153 | struct db8500_thermal_zone *th = NULL; | |
154 | struct device *dev = &pdev->dev; | |
155 | int low_irq, high_irq, ret = 0; | |
156 | ||
157 | th = devm_kzalloc(dev, sizeof(*th), GFP_KERNEL); | |
158 | if (!th) | |
159 | return -ENOMEM; | |
160 | ||
161 | th->dev = dev; | |
162 | ||
163 | low_irq = platform_get_irq_byname(pdev, "IRQ_HOTMON_LOW"); | |
164 | if (low_irq < 0) | |
165 | return low_irq; | |
166 | ||
167 | ret = devm_request_threaded_irq(dev, low_irq, NULL, | |
168 | prcmu_low_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT, | |
169 | "dbx500_temp_low", th); | |
170 | if (ret < 0) { | |
171 | dev_err(dev, "failed to allocate temp low irq\n"); | |
172 | return ret; | |
173 | } | |
174 | ||
175 | high_irq = platform_get_irq_byname(pdev, "IRQ_HOTMON_HIGH"); | |
176 | if (high_irq < 0) | |
177 | return high_irq; | |
178 | ||
179 | ret = devm_request_threaded_irq(dev, high_irq, NULL, | |
180 | prcmu_high_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT, | |
181 | "dbx500_temp_high", th); | |
182 | if (ret < 0) { | |
183 | dev_err(dev, "failed to allocate temp high irq\n"); | |
184 | return ret; | |
185 | } | |
186 | ||
187 | /* register of thermal sensor and get info from DT */ | |
188 | th->tz = devm_thermal_of_zone_register(dev, 0, th, &thdev_ops); | |
189 | if (IS_ERR(th->tz)) { | |
190 | dev_err(dev, "register thermal zone sensor failed\n"); | |
191 | return PTR_ERR(th->tz); | |
192 | } | |
193 | dev_info(dev, "thermal zone sensor registered\n"); | |
194 | ||
195 | /* Start measuring at the lowest point */ | |
196 | db8500_thermal_update_config(th, 0, PRCMU_DEFAULT_LOW_TEMP, | |
197 | db8500_thermal_points[0]); | |
198 | ||
199 | platform_set_drvdata(pdev, th); | |
200 | ||
201 | return 0; | |
202 | } | |
203 | ||
204 | static int db8500_thermal_suspend(struct platform_device *pdev, | |
205 | pm_message_t state) | |
206 | { | |
207 | prcmu_stop_temp_sense(); | |
208 | ||
209 | return 0; | |
210 | } | |
211 | ||
212 | static int db8500_thermal_resume(struct platform_device *pdev) | |
213 | { | |
214 | struct db8500_thermal_zone *th = platform_get_drvdata(pdev); | |
215 | ||
216 | /* Resume and start measuring at the lowest point */ | |
217 | db8500_thermal_update_config(th, 0, PRCMU_DEFAULT_LOW_TEMP, | |
218 | db8500_thermal_points[0]); | |
219 | ||
220 | return 0; | |
221 | } | |
222 | ||
223 | static const struct of_device_id db8500_thermal_match[] = { | |
224 | { .compatible = "stericsson,db8500-thermal" }, | |
225 | {}, | |
226 | }; | |
227 | MODULE_DEVICE_TABLE(of, db8500_thermal_match); | |
228 | ||
229 | static struct platform_driver db8500_thermal_driver = { | |
230 | .driver = { | |
231 | .name = "db8500-thermal", | |
232 | .of_match_table = db8500_thermal_match, | |
233 | }, | |
234 | .probe = db8500_thermal_probe, | |
235 | .suspend = db8500_thermal_suspend, | |
236 | .resume = db8500_thermal_resume, | |
237 | }; | |
238 | ||
239 | module_platform_driver(db8500_thermal_driver); | |
240 | ||
241 | MODULE_AUTHOR("Hongbo Zhang <hongbo.zhang@stericsson.com>"); | |
242 | MODULE_DESCRIPTION("DB8500 thermal driver"); | |
243 | MODULE_LICENSE("GPL"); |