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7060aa36 NI |
1 | /* |
2 | * Kirkwood thermal sensor driver | |
3 | * | |
4 | * Copyright (C) 2012 Nobuhiro Iwamatsu <iwamatsu@nigauri.org> | |
5 | * | |
6 | * This software is licensed under the terms of the GNU General Public | |
7 | * License version 2, as published by the Free Software Foundation, and | |
8 | * may be copied, distributed, and modified under those terms. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | */ | |
16 | #include <linux/device.h> | |
17 | #include <linux/err.h> | |
18 | #include <linux/io.h> | |
19 | #include <linux/kernel.h> | |
20 | #include <linux/of.h> | |
21 | #include <linux/module.h> | |
22 | #include <linux/platform_device.h> | |
23 | #include <linux/thermal.h> | |
24 | ||
25 | #define KIRKWOOD_THERMAL_VALID_OFFSET 9 | |
26 | #define KIRKWOOD_THERMAL_VALID_MASK 0x1 | |
27 | #define KIRKWOOD_THERMAL_TEMP_OFFSET 10 | |
28 | #define KIRKWOOD_THERMAL_TEMP_MASK 0x1FF | |
29 | ||
30 | /* Kirkwood Thermal Sensor Dev Structure */ | |
31 | struct kirkwood_thermal_priv { | |
32 | void __iomem *sensor; | |
33 | }; | |
34 | ||
35 | static int kirkwood_get_temp(struct thermal_zone_device *thermal, | |
36 | unsigned long *temp) | |
37 | { | |
38 | unsigned long reg; | |
39 | struct kirkwood_thermal_priv *priv = thermal->devdata; | |
40 | ||
41 | reg = readl_relaxed(priv->sensor); | |
42 | ||
43 | /* Valid check */ | |
44 | if (!(reg >> KIRKWOOD_THERMAL_VALID_OFFSET) & | |
45 | KIRKWOOD_THERMAL_VALID_MASK) { | |
46 | dev_err(&thermal->device, | |
47 | "Temperature sensor reading not valid\n"); | |
48 | return -EIO; | |
49 | } | |
50 | ||
51 | /* | |
52 | * Calculate temperature. See Section 8.10.1 of the 88AP510, | |
53 | * datasheet, which has the same sensor. | |
54 | * Documentation/arm/Marvell/README | |
55 | */ | |
56 | reg = (reg >> KIRKWOOD_THERMAL_TEMP_OFFSET) & | |
57 | KIRKWOOD_THERMAL_TEMP_MASK; | |
58 | *temp = ((2281638UL - (7298*reg)) / 10); | |
59 | ||
60 | return 0; | |
61 | } | |
62 | ||
63 | static struct thermal_zone_device_ops ops = { | |
64 | .get_temp = kirkwood_get_temp, | |
65 | }; | |
66 | ||
67 | static const struct of_device_id kirkwood_thermal_id_table[] = { | |
68 | { .compatible = "marvell,kirkwood-thermal" }, | |
69 | {} | |
70 | }; | |
71 | ||
72 | static int kirkwood_thermal_probe(struct platform_device *pdev) | |
73 | { | |
74 | struct thermal_zone_device *thermal = NULL; | |
75 | struct kirkwood_thermal_priv *priv; | |
76 | struct resource *res; | |
77 | ||
78 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
79 | if (!res) { | |
80 | dev_err(&pdev->dev, "Failed to get platform resource\n"); | |
81 | return -ENODEV; | |
82 | } | |
83 | ||
84 | priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); | |
85 | if (!priv) | |
86 | return -ENOMEM; | |
87 | ||
aa3b5d22 SK |
88 | priv->sensor = devm_ioremap_resource(&pdev->dev, res); |
89 | if (IS_ERR(priv->sensor)) | |
90 | return PTR_ERR(priv->sensor); | |
7060aa36 NI |
91 | |
92 | thermal = thermal_zone_device_register("kirkwood_thermal", 0, 0, | |
93 | priv, &ops, NULL, 0, 0); | |
94 | if (IS_ERR(thermal)) { | |
95 | dev_err(&pdev->dev, | |
96 | "Failed to register thermal zone device\n"); | |
97 | return PTR_ERR(thermal); | |
98 | } | |
99 | ||
100 | platform_set_drvdata(pdev, thermal); | |
101 | ||
102 | return 0; | |
103 | } | |
104 | ||
105 | static int kirkwood_thermal_exit(struct platform_device *pdev) | |
106 | { | |
107 | struct thermal_zone_device *kirkwood_thermal = | |
108 | platform_get_drvdata(pdev); | |
109 | ||
110 | thermal_zone_device_unregister(kirkwood_thermal); | |
111 | platform_set_drvdata(pdev, NULL); | |
112 | ||
113 | return 0; | |
114 | } | |
115 | ||
116 | MODULE_DEVICE_TABLE(of, kirkwood_thermal_id_table); | |
117 | ||
118 | static struct platform_driver kirkwood_thermal_driver = { | |
119 | .probe = kirkwood_thermal_probe, | |
120 | .remove = kirkwood_thermal_exit, | |
121 | .driver = { | |
122 | .name = "kirkwood_thermal", | |
123 | .owner = THIS_MODULE, | |
124 | .of_match_table = of_match_ptr(kirkwood_thermal_id_table), | |
125 | }, | |
126 | }; | |
127 | ||
128 | module_platform_driver(kirkwood_thermal_driver); | |
129 | ||
130 | MODULE_AUTHOR("Nobuhiro Iwamatsu <iwamatsu@nigauri.org>"); | |
131 | MODULE_DESCRIPTION("kirkwood thermal driver"); | |
132 | MODULE_LICENSE("GPL"); |