ns-thermal.c

 1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * Copyright (C) 2017 Rafał Miłecki <rafal@milecki.pl>
 4 */
 5
 6#include <linux/module.h>
 7#include <linux/of_address.h>
 8#include <linux/platform_device.h>
 9#include <linux/thermal.h>
10
11#define PVTMON_CONTROL0					0x00
12#define PVTMON_CONTROL0_SEL_MASK			0x0000000e
13#define PVTMON_CONTROL0_SEL_TEMP_MONITOR		0x00000000
14#define PVTMON_CONTROL0_SEL_TEST_MODE			0x0000000e
15#define PVTMON_STATUS					0x08
16
17static int ns_thermal_get_temp(struct thermal_zone_device *tz, int *temp)
18{
19	void __iomem *pvtmon = thermal_zone_device_priv(tz);
20	int offset = thermal_zone_get_offset(tz);
21	int slope = thermal_zone_get_slope(tz);
22	u32 val;
23
24	val = readl(pvtmon + PVTMON_CONTROL0);
25	if ((val & PVTMON_CONTROL0_SEL_MASK) != PVTMON_CONTROL0_SEL_TEMP_MONITOR) {
26		/* Clear current mode selection */
27		val &= ~PVTMON_CONTROL0_SEL_MASK;
28
29		/* Set temp monitor mode (it's the default actually) */
30		val |= PVTMON_CONTROL0_SEL_TEMP_MONITOR;
31
32		writel(val, pvtmon + PVTMON_CONTROL0);
33	}
34
35	val = readl(pvtmon + PVTMON_STATUS);
36	*temp = slope * val + offset;
37
38	return 0;
39}
40
41static const struct thermal_zone_device_ops ns_thermal_ops = {
42	.get_temp = ns_thermal_get_temp,
43};
44
45static int ns_thermal_probe(struct platform_device *pdev)
46{
47	struct device *dev = &pdev->dev;
48	struct thermal_zone_device *tz;
49	void __iomem *pvtmon;
50
51	pvtmon = of_iomap(dev_of_node(dev), 0);
52	if (WARN_ON(!pvtmon))
53		return -ENOENT;
54
55	tz = devm_thermal_of_zone_register(dev, 0,
56					   pvtmon,
57					   &ns_thermal_ops);
58	if (IS_ERR(tz)) {
59		iounmap(pvtmon);
60		return PTR_ERR(tz);
61	}
62
63	platform_set_drvdata(pdev, pvtmon);
64
65	return 0;
66}
67
68static void ns_thermal_remove(struct platform_device *pdev)
69{
70	void __iomem *pvtmon = platform_get_drvdata(pdev);
71
72	iounmap(pvtmon);
73}
74
75static const struct of_device_id ns_thermal_of_match[] = {
76	{ .compatible = "brcm,ns-thermal", },
77	{},
78};
79MODULE_DEVICE_TABLE(of, ns_thermal_of_match);
80
81static struct platform_driver ns_thermal_driver = {
82	.probe		= ns_thermal_probe,
83	.remove		= ns_thermal_remove,
84	.driver = {
85		.name = "ns-thermal",
86		.of_match_table = ns_thermal_of_match,
87	},
88};
89module_platform_driver(ns_thermal_driver);
90
91MODULE_AUTHOR("Rafał Miłecki <rafal@milecki.pl>");
92MODULE_DESCRIPTION("Northstar thermal driver");
93MODULE_LICENSE("GPL v2");