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(tzd: 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(low: (u8)(next_low/1000), high: (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, size: 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, irq: low_irq, NULL, |
168 | thread_fn: prcmu_low_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT, |
169 | devname: "dbx500_temp_low" , dev_id: 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, irq: high_irq, NULL, |
180 | thread_fn: prcmu_high_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT, |
181 | devname: "dbx500_temp_high" , dev_id: 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, id: 0, data: th, ops: &thdev_ops); |
189 | if (IS_ERR(ptr: th->tz)) { |
190 | dev_err(dev, "register thermal zone sensor failed\n" ); |
191 | return PTR_ERR(ptr: 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, idx: 0, PRCMU_DEFAULT_LOW_TEMP, |
197 | next_high: db8500_thermal_points[0]); |
198 | |
199 | platform_set_drvdata(pdev, data: 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, idx: 0, PRCMU_DEFAULT_LOW_TEMP, |
218 | next_high: 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" ); |
244 | |