1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Khadas MCU Controlled FAN driver
4 *
5 * Copyright (C) 2020 BayLibre SAS
6 * Author(s): Neil Armstrong <narmstrong@baylibre.com>
7 */
8
9#include <linux/module.h>
10#include <linux/of.h>
11#include <linux/platform_device.h>
12#include <linux/mfd/khadas-mcu.h>
13#include <linux/regmap.h>
14#include <linux/sysfs.h>
15#include <linux/thermal.h>
16
17#define MAX_LEVEL 3
18
19struct khadas_mcu_fan_ctx {
20 struct khadas_mcu *mcu;
21 unsigned int level;
22 struct thermal_cooling_device *cdev;
23};
24
25static int khadas_mcu_fan_set_level(struct khadas_mcu_fan_ctx *ctx,
26 unsigned int level)
27{
28 int ret;
29
30 ret = regmap_write(map: ctx->mcu->regmap, KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG,
31 val: level);
32 if (ret)
33 return ret;
34
35 ctx->level = level;
36
37 return 0;
38}
39
40static int khadas_mcu_fan_get_max_state(struct thermal_cooling_device *cdev,
41 unsigned long *state)
42{
43 *state = MAX_LEVEL;
44
45 return 0;
46}
47
48static int khadas_mcu_fan_get_cur_state(struct thermal_cooling_device *cdev,
49 unsigned long *state)
50{
51 struct khadas_mcu_fan_ctx *ctx = cdev->devdata;
52
53 *state = ctx->level;
54
55 return 0;
56}
57
58static int
59khadas_mcu_fan_set_cur_state(struct thermal_cooling_device *cdev,
60 unsigned long state)
61{
62 struct khadas_mcu_fan_ctx *ctx = cdev->devdata;
63
64 if (state > MAX_LEVEL)
65 return -EINVAL;
66
67 if (state == ctx->level)
68 return 0;
69
70 return khadas_mcu_fan_set_level(ctx, level: state);
71}
72
73static const struct thermal_cooling_device_ops khadas_mcu_fan_cooling_ops = {
74 .get_max_state = khadas_mcu_fan_get_max_state,
75 .get_cur_state = khadas_mcu_fan_get_cur_state,
76 .set_cur_state = khadas_mcu_fan_set_cur_state,
77};
78
79static int khadas_mcu_fan_probe(struct platform_device *pdev)
80{
81 struct khadas_mcu *mcu = dev_get_drvdata(dev: pdev->dev.parent);
82 struct thermal_cooling_device *cdev;
83 struct device *dev = &pdev->dev;
84 struct khadas_mcu_fan_ctx *ctx;
85 int ret;
86
87 ctx = devm_kzalloc(dev, size: sizeof(*ctx), GFP_KERNEL);
88 if (!ctx)
89 return -ENOMEM;
90 ctx->mcu = mcu;
91 platform_set_drvdata(pdev, data: ctx);
92
93 cdev = devm_thermal_of_cooling_device_register(dev: dev->parent,
94 np: dev->parent->of_node, type: "khadas-mcu-fan", devdata: ctx,
95 ops: &khadas_mcu_fan_cooling_ops);
96 if (IS_ERR(ptr: cdev)) {
97 ret = PTR_ERR(ptr: cdev);
98 dev_err(dev, "Failed to register khadas-mcu-fan as cooling device: %d\n",
99 ret);
100 return ret;
101 }
102 ctx->cdev = cdev;
103
104 return 0;
105}
106
107static void khadas_mcu_fan_shutdown(struct platform_device *pdev)
108{
109 struct khadas_mcu_fan_ctx *ctx = platform_get_drvdata(pdev);
110
111 khadas_mcu_fan_set_level(ctx, level: 0);
112}
113
114#ifdef CONFIG_PM_SLEEP
115static int khadas_mcu_fan_suspend(struct device *dev)
116{
117 struct khadas_mcu_fan_ctx *ctx = dev_get_drvdata(dev);
118 unsigned int level_save = ctx->level;
119 int ret;
120
121 ret = khadas_mcu_fan_set_level(ctx, level: 0);
122 if (ret)
123 return ret;
124
125 ctx->level = level_save;
126
127 return 0;
128}
129
130static int khadas_mcu_fan_resume(struct device *dev)
131{
132 struct khadas_mcu_fan_ctx *ctx = dev_get_drvdata(dev);
133
134 return khadas_mcu_fan_set_level(ctx, level: ctx->level);
135}
136#endif
137
138static SIMPLE_DEV_PM_OPS(khadas_mcu_fan_pm, khadas_mcu_fan_suspend,
139 khadas_mcu_fan_resume);
140
141static const struct platform_device_id khadas_mcu_fan_id_table[] = {
142 { .name = "khadas-mcu-fan-ctrl", },
143 {},
144};
145MODULE_DEVICE_TABLE(platform, khadas_mcu_fan_id_table);
146
147static struct platform_driver khadas_mcu_fan_driver = {
148 .probe = khadas_mcu_fan_probe,
149 .shutdown = khadas_mcu_fan_shutdown,
150 .driver = {
151 .name = "khadas-mcu-fan-ctrl",
152 .pm = &khadas_mcu_fan_pm,
153 },
154 .id_table = khadas_mcu_fan_id_table,
155};
156
157module_platform_driver(khadas_mcu_fan_driver);
158
159MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
160MODULE_DESCRIPTION("Khadas MCU FAN driver");
161MODULE_LICENSE("GPL");
162

source code of linux/drivers/thermal/khadas_mcu_fan.c