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
19 struct khadas_mcu_fan_ctx {
20 struct khadas_mcu *mcu;
21 unsigned int level;
22 struct thermal_cooling_device *cdev;
23 };
24
khadas_mcu_fan_set_level(struct khadas_mcu_fan_ctx * ctx,unsigned int level)25 static 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(ctx->mcu->regmap, KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG,
31 level);
32 if (ret)
33 return ret;
34
35 ctx->level = level;
36
37 return 0;
38 }
39
khadas_mcu_fan_get_max_state(struct thermal_cooling_device * cdev,unsigned long * state)40 static 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
khadas_mcu_fan_get_cur_state(struct thermal_cooling_device * cdev,unsigned long * state)48 static 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
58 static int
khadas_mcu_fan_set_cur_state(struct thermal_cooling_device * cdev,unsigned long state)59 khadas_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, state);
71 }
72
73 static 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
khadas_mcu_fan_probe(struct platform_device * pdev)79 static int khadas_mcu_fan_probe(struct platform_device *pdev)
80 {
81 struct khadas_mcu *mcu = dev_get_drvdata(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, sizeof(*ctx), GFP_KERNEL);
88 if (!ctx)
89 return -ENOMEM;
90 ctx->mcu = mcu;
91 platform_set_drvdata(pdev, ctx);
92
93 cdev = devm_thermal_of_cooling_device_register(dev->parent,
94 dev->parent->of_node, "khadas-mcu-fan", ctx,
95 &khadas_mcu_fan_cooling_ops);
96 if (IS_ERR(cdev)) {
97 ret = PTR_ERR(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 thermal_cdev_update(cdev);
104
105 return 0;
106 }
107
khadas_mcu_fan_shutdown(struct platform_device * pdev)108 static void khadas_mcu_fan_shutdown(struct platform_device *pdev)
109 {
110 struct khadas_mcu_fan_ctx *ctx = platform_get_drvdata(pdev);
111
112 khadas_mcu_fan_set_level(ctx, 0);
113 }
114
115 #ifdef CONFIG_PM_SLEEP
khadas_mcu_fan_suspend(struct device * dev)116 static int khadas_mcu_fan_suspend(struct device *dev)
117 {
118 struct khadas_mcu_fan_ctx *ctx = dev_get_drvdata(dev);
119 unsigned int level_save = ctx->level;
120 int ret;
121
122 ret = khadas_mcu_fan_set_level(ctx, 0);
123 if (ret)
124 return ret;
125
126 ctx->level = level_save;
127
128 return 0;
129 }
130
khadas_mcu_fan_resume(struct device * dev)131 static int khadas_mcu_fan_resume(struct device *dev)
132 {
133 struct khadas_mcu_fan_ctx *ctx = dev_get_drvdata(dev);
134
135 return khadas_mcu_fan_set_level(ctx, ctx->level);
136 }
137 #endif
138
139 static SIMPLE_DEV_PM_OPS(khadas_mcu_fan_pm, khadas_mcu_fan_suspend,
140 khadas_mcu_fan_resume);
141
142 static const struct platform_device_id khadas_mcu_fan_id_table[] = {
143 { .name = "khadas-mcu-fan-ctrl", },
144 {},
145 };
146 MODULE_DEVICE_TABLE(platform, khadas_mcu_fan_id_table);
147
148 static struct platform_driver khadas_mcu_fan_driver = {
149 .probe = khadas_mcu_fan_probe,
150 .shutdown = khadas_mcu_fan_shutdown,
151 .driver = {
152 .name = "khadas-mcu-fan-ctrl",
153 .pm = &khadas_mcu_fan_pm,
154 },
155 .id_table = khadas_mcu_fan_id_table,
156 };
157
158 module_platform_driver(khadas_mcu_fan_driver);
159
160 MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
161 MODULE_DESCRIPTION("Khadas MCU FAN driver");
162 MODULE_LICENSE("GPL");
163