1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Junction temperature thermal driver for Maxim Max77620.
4 *
5 * Copyright (c) 2016, NVIDIA CORPORATION.  All rights reserved.
6 *
7 * Author: Laxman Dewangan <ldewangan@nvidia.com>
8 *	   Mallikarjun Kasoju <mkasoju@nvidia.com>
9 */
10
11#include <linux/irq.h>
12#include <linux/interrupt.h>
13#include <linux/mfd/max77620.h>
14#include <linux/module.h>
15#include <linux/of.h>
16#include <linux/platform_device.h>
17#include <linux/regmap.h>
18#include <linux/slab.h>
19#include <linux/thermal.h>
20
21#define MAX77620_NORMAL_OPERATING_TEMP	100000
22#define MAX77620_TJALARM1_TEMP		120000
23#define MAX77620_TJALARM2_TEMP		140000
24
25struct max77620_therm_info {
26	struct device			*dev;
27	struct regmap			*rmap;
28	struct thermal_zone_device	*tz_device;
29	int				irq_tjalarm1;
30	int				irq_tjalarm2;
31};
32
33/**
34 * max77620_thermal_read_temp: Read PMIC die temperatue.
35 * @data:	Device specific data.
36 * @temp:	Temperature in millidegrees Celsius
37 *
38 * The actual temperature of PMIC die is not available from PMIC.
39 * PMIC only tells the status if it has crossed or not the threshold level
40 * of 120degC or 140degC.
41 * If threshold has not been crossed then assume die temperature as 100degC
42 * else 120degC or 140deG based on the PMIC die temp threshold status.
43 *
44 * Return 0 on success otherwise error number to show reason of failure.
45 */
46
47static int max77620_thermal_read_temp(struct thermal_zone_device *tz, int *temp)
48{
49	struct max77620_therm_info *mtherm = thermal_zone_device_priv(tz);
50	unsigned int val;
51	int ret;
52
53	ret = regmap_read(mtherm->rmap, MAX77620_REG_STATLBT, &val);
54	if (ret < 0)
55		return ret;
56
57	if (val & MAX77620_IRQ_TJALRM2_MASK)
58		*temp = MAX77620_TJALARM2_TEMP;
59	else if (val & MAX77620_IRQ_TJALRM1_MASK)
60		*temp = MAX77620_TJALARM1_TEMP;
61	else
62		*temp = MAX77620_NORMAL_OPERATING_TEMP;
63
64	return 0;
65}
66
67static const struct thermal_zone_device_ops max77620_thermal_ops = {
68	.get_temp = max77620_thermal_read_temp,
69};
70
71static irqreturn_t max77620_thermal_irq(int irq, void *data)
72{
73	struct max77620_therm_info *mtherm = data;
74
75	if (irq == mtherm->irq_tjalarm1)
76		dev_warn(mtherm->dev, "Junction Temp Alarm1(120C) occurred\n");
77	else if (irq == mtherm->irq_tjalarm2)
78		dev_crit(mtherm->dev, "Junction Temp Alarm2(140C) occurred\n");
79
80	thermal_zone_device_update(mtherm->tz_device,
81				   THERMAL_EVENT_UNSPECIFIED);
82
83	return IRQ_HANDLED;
84}
85
86static int max77620_thermal_probe(struct platform_device *pdev)
87{
88	struct max77620_therm_info *mtherm;
89	int ret;
90
91	mtherm = devm_kzalloc(&pdev->dev, sizeof(*mtherm), GFP_KERNEL);
92	if (!mtherm)
93		return -ENOMEM;
94
95	mtherm->irq_tjalarm1 = platform_get_irq(pdev, 0);
96	mtherm->irq_tjalarm2 = platform_get_irq(pdev, 1);
97	if ((mtherm->irq_tjalarm1 < 0) || (mtherm->irq_tjalarm2 < 0)) {
98		dev_err(&pdev->dev, "Alarm irq number not available\n");
99		return -EINVAL;
100	}
101
102	mtherm->dev = &pdev->dev;
103	mtherm->rmap = dev_get_regmap(pdev->dev.parent, NULL);
104	if (!mtherm->rmap) {
105		dev_err(&pdev->dev, "Failed to get parent regmap\n");
106		return -ENODEV;
107	}
108
109	/*
110	 * The reference taken to the parent's node which will be balanced on
111	 * reprobe or on platform-device release.
112	 */
113	device_set_of_node_from_dev(&pdev->dev, pdev->dev.parent);
114
115	mtherm->tz_device = devm_thermal_of_zone_register(&pdev->dev, 0,
116				mtherm, &max77620_thermal_ops);
117	if (IS_ERR(mtherm->tz_device)) {
118		ret = PTR_ERR(mtherm->tz_device);
119		dev_err(&pdev->dev, "Failed to register thermal zone: %d\n",
120			ret);
121		return ret;
122	}
123
124	ret = devm_request_threaded_irq(&pdev->dev, mtherm->irq_tjalarm1, NULL,
125					max77620_thermal_irq,
126					IRQF_ONESHOT | IRQF_SHARED,
127					dev_name(&pdev->dev), mtherm);
128	if (ret < 0) {
129		dev_err(&pdev->dev, "Failed to request irq1: %d\n", ret);
130		return ret;
131	}
132
133	ret = devm_request_threaded_irq(&pdev->dev, mtherm->irq_tjalarm2, NULL,
134					max77620_thermal_irq,
135					IRQF_ONESHOT | IRQF_SHARED,
136					dev_name(&pdev->dev), mtherm);
137	if (ret < 0) {
138		dev_err(&pdev->dev, "Failed to request irq2: %d\n", ret);
139		return ret;
140	}
141
142	return 0;
143}
144
145static struct platform_device_id max77620_thermal_devtype[] = {
146	{ .name = "max77620-thermal", },
147	{},
148};
149MODULE_DEVICE_TABLE(platform, max77620_thermal_devtype);
150
151static struct platform_driver max77620_thermal_driver = {
152	.driver = {
153		.name = "max77620-thermal",
154	},
155	.probe = max77620_thermal_probe,
156	.id_table = max77620_thermal_devtype,
157};
158
159module_platform_driver(max77620_thermal_driver);
160
161MODULE_DESCRIPTION("Max77620 Junction temperature Thermal driver");
162MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
163MODULE_AUTHOR("Mallikarjun Kasoju <mkasoju@nvidia.com>");
164MODULE_LICENSE("GPL v2");
165