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 | |
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(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 | |
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 | |
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 |
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, level: 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 | |
79 | static 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 | |
107 | static 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 |
115 | static 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 | |
130 | static 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 | |
138 | static SIMPLE_DEV_PM_OPS(khadas_mcu_fan_pm, khadas_mcu_fan_suspend, |
139 | khadas_mcu_fan_resume); |
140 | |
141 | static const struct platform_device_id khadas_mcu_fan_id_table[] = { |
142 | { .name = "khadas-mcu-fan-ctrl" , }, |
143 | {}, |
144 | }; |
145 | MODULE_DEVICE_TABLE(platform, khadas_mcu_fan_id_table); |
146 | |
147 | static 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 | |
157 | module_platform_driver(khadas_mcu_fan_driver); |
158 | |
159 | MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>" ); |
160 | MODULE_DESCRIPTION("Khadas MCU FAN driver" ); |
161 | MODULE_LICENSE("GPL" ); |
162 | |