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59b78135 SW |
1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* | |
3 | * Broadcom AVS RO thermal sensor driver | |
4 | * | |
5 | * based on brcmstb_thermal | |
6 | * | |
7 | * Copyright (C) 2020 Stefan Wahren | |
8 | */ | |
9 | ||
10 | #include <linux/bitops.h> | |
11 | #include <linux/clk.h> | |
12 | #include <linux/device.h> | |
13 | #include <linux/err.h> | |
14 | #include <linux/io.h> | |
15 | #include <linux/kernel.h> | |
16 | #include <linux/mfd/syscon.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/platform_device.h> | |
19 | #include <linux/of_device.h> | |
20 | #include <linux/regmap.h> | |
21 | #include <linux/thermal.h> | |
22 | ||
23 | #include "../thermal_hwmon.h" | |
24 | ||
25 | #define AVS_RO_TEMP_STATUS 0x200 | |
26 | #define AVS_RO_TEMP_STATUS_VALID_MSK (BIT(16) | BIT(10)) | |
27 | #define AVS_RO_TEMP_STATUS_DATA_MSK GENMASK(9, 0) | |
28 | ||
29 | struct bcm2711_thermal_priv { | |
30 | struct regmap *regmap; | |
31 | struct thermal_zone_device *thermal; | |
32 | }; | |
33 | ||
34 | static int bcm2711_get_temp(void *data, int *temp) | |
35 | { | |
36 | struct bcm2711_thermal_priv *priv = data; | |
37 | int slope = thermal_zone_get_slope(priv->thermal); | |
38 | int offset = thermal_zone_get_offset(priv->thermal); | |
39 | u32 val; | |
40 | int ret; | |
41 | long t; | |
42 | ||
43 | ret = regmap_read(priv->regmap, AVS_RO_TEMP_STATUS, &val); | |
44 | if (ret) | |
45 | return ret; | |
46 | ||
47 | if (!(val & AVS_RO_TEMP_STATUS_VALID_MSK)) | |
48 | return -EIO; | |
49 | ||
50 | val &= AVS_RO_TEMP_STATUS_DATA_MSK; | |
51 | ||
52 | /* Convert a HW code to a temperature reading (millidegree celsius) */ | |
53 | t = slope * val + offset; | |
54 | ||
55 | *temp = t < 0 ? 0 : t; | |
56 | ||
57 | return 0; | |
58 | } | |
59 | ||
60 | static const struct thermal_zone_of_device_ops bcm2711_thermal_of_ops = { | |
61 | .get_temp = bcm2711_get_temp, | |
62 | }; | |
63 | ||
64 | static const struct of_device_id bcm2711_thermal_id_table[] = { | |
65 | { .compatible = "brcm,bcm2711-thermal" }, | |
66 | {}, | |
67 | }; | |
68 | MODULE_DEVICE_TABLE(of, bcm2711_thermal_id_table); | |
69 | ||
70 | static int bcm2711_thermal_probe(struct platform_device *pdev) | |
71 | { | |
72 | struct thermal_zone_device *thermal; | |
73 | struct bcm2711_thermal_priv *priv; | |
74 | struct device *dev = &pdev->dev; | |
75 | struct device_node *parent; | |
76 | struct regmap *regmap; | |
77 | int ret; | |
78 | ||
79 | priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); | |
80 | if (!priv) | |
81 | return -ENOMEM; | |
82 | ||
83 | /* get regmap from syscon node */ | |
84 | parent = of_get_parent(dev->of_node); /* parent should be syscon node */ | |
85 | regmap = syscon_node_to_regmap(parent); | |
86 | of_node_put(parent); | |
87 | if (IS_ERR(regmap)) { | |
88 | ret = PTR_ERR(regmap); | |
89 | dev_err(dev, "failed to get regmap: %d\n", ret); | |
90 | return ret; | |
91 | } | |
92 | priv->regmap = regmap; | |
93 | ||
94 | thermal = devm_thermal_zone_of_sensor_register(dev, 0, priv, | |
95 | &bcm2711_thermal_of_ops); | |
96 | if (IS_ERR(thermal)) { | |
97 | ret = PTR_ERR(thermal); | |
98 | dev_err(dev, "could not register sensor: %d\n", ret); | |
99 | return ret; | |
100 | } | |
101 | ||
102 | priv->thermal = thermal; | |
103 | ||
104 | thermal->tzp->no_hwmon = false; | |
ea21f589 | 105 | return thermal_add_hwmon_sysfs(thermal); |
59b78135 SW |
106 | } |
107 | ||
108 | static struct platform_driver bcm2711_thermal_driver = { | |
109 | .probe = bcm2711_thermal_probe, | |
110 | .driver = { | |
111 | .name = "bcm2711_thermal", | |
112 | .of_match_table = bcm2711_thermal_id_table, | |
113 | }, | |
114 | }; | |
115 | module_platform_driver(bcm2711_thermal_driver); | |
116 | ||
117 | MODULE_LICENSE("GPL"); | |
118 | MODULE_AUTHOR("Stefan Wahren"); | |
119 | MODULE_DESCRIPTION("Broadcom AVS RO thermal sensor driver"); |