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/of.h>
19 #include <linux/platform_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
bcm2711_get_temp(struct thermal_zone_device * tz,int * temp)34 static int bcm2711_get_temp(struct thermal_zone_device *tz, int *temp)
35 {
36 struct bcm2711_thermal_priv *priv = thermal_zone_device_priv(tz);
37 int slope = thermal_zone_get_slope(tz);
38 int offset = thermal_zone_get_offset(tz);
39 u32 val;
40 int ret;
41
42 ret = regmap_read(priv->regmap, AVS_RO_TEMP_STATUS, &val);
43 if (ret)
44 return ret;
45
46 if (!(val & AVS_RO_TEMP_STATUS_VALID_MSK))
47 return -EIO;
48
49 val &= AVS_RO_TEMP_STATUS_DATA_MSK;
50
51 /* Convert a HW code to a temperature reading (millidegree celsius) */
52 *temp = slope * val + offset;
53
54 return 0;
55 }
56
57 static const struct thermal_zone_device_ops bcm2711_thermal_of_ops = {
58 .get_temp = bcm2711_get_temp,
59 };
60
61 static const struct of_device_id bcm2711_thermal_id_table[] = {
62 { .compatible = "brcm,bcm2711-thermal" },
63 {},
64 };
65 MODULE_DEVICE_TABLE(of, bcm2711_thermal_id_table);
66
bcm2711_thermal_probe(struct platform_device * pdev)67 static int bcm2711_thermal_probe(struct platform_device *pdev)
68 {
69 struct thermal_zone_device *thermal;
70 struct bcm2711_thermal_priv *priv;
71 struct device *dev = &pdev->dev;
72 struct device_node *parent;
73 struct regmap *regmap;
74 int ret;
75
76 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
77 if (!priv)
78 return -ENOMEM;
79
80 /* get regmap from syscon node */
81 parent = of_get_parent(dev->of_node); /* parent should be syscon node */
82 regmap = syscon_node_to_regmap(parent);
83 of_node_put(parent);
84 if (IS_ERR(regmap)) {
85 ret = PTR_ERR(regmap);
86 dev_err(dev, "failed to get regmap: %d\n", ret);
87 return ret;
88 }
89 priv->regmap = regmap;
90
91 thermal = devm_thermal_of_zone_register(dev, 0, priv,
92 &bcm2711_thermal_of_ops);
93 if (IS_ERR(thermal)) {
94 ret = PTR_ERR(thermal);
95 dev_err(dev, "could not register sensor: %d\n", ret);
96 return ret;
97 }
98
99 priv->thermal = thermal;
100
101 return thermal_add_hwmon_sysfs(thermal);
102 }
103
104 static struct platform_driver bcm2711_thermal_driver = {
105 .probe = bcm2711_thermal_probe,
106 .driver = {
107 .name = "bcm2711_thermal",
108 .of_match_table = bcm2711_thermal_id_table,
109 },
110 };
111 module_platform_driver(bcm2711_thermal_driver);
112
113 MODULE_LICENSE("GPL");
114 MODULE_AUTHOR("Stefan Wahren");
115 MODULE_DESCRIPTION("Broadcom AVS RO thermal sensor driver");
116