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 
25 struct 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 
47 static int max77620_thermal_read_temp(struct thermal_zone_device *tz, int *temp)
48 {
49 	struct max77620_therm_info *mtherm = tz->devdata;
50 	unsigned int val;
51 	int ret;
52 
53 	ret = regmap_read(mtherm->rmap, MAX77620_REG_STATLBT, &val);
54 	if (ret < 0) {
55 		dev_err(mtherm->dev, "Failed to read STATLBT: %d\n", ret);
56 		return ret;
57 	}
58 
59 	if (val & MAX77620_IRQ_TJALRM2_MASK)
60 		*temp = MAX77620_TJALARM2_TEMP;
61 	else if (val & MAX77620_IRQ_TJALRM1_MASK)
62 		*temp = MAX77620_TJALARM1_TEMP;
63 	else
64 		*temp = MAX77620_NORMAL_OPERATING_TEMP;
65 
66 	return 0;
67 }
68 
69 static const struct thermal_zone_device_ops max77620_thermal_ops = {
70 	.get_temp = max77620_thermal_read_temp,
71 };
72 
73 static irqreturn_t max77620_thermal_irq(int irq, void *data)
74 {
75 	struct max77620_therm_info *mtherm = data;
76 
77 	if (irq == mtherm->irq_tjalarm1)
78 		dev_warn(mtherm->dev, "Junction Temp Alarm1(120C) occurred\n");
79 	else if (irq == mtherm->irq_tjalarm2)
80 		dev_crit(mtherm->dev, "Junction Temp Alarm2(140C) occurred\n");
81 
82 	thermal_zone_device_update(mtherm->tz_device,
83 				   THERMAL_EVENT_UNSPECIFIED);
84 
85 	return IRQ_HANDLED;
86 }
87 
88 static int max77620_thermal_probe(struct platform_device *pdev)
89 {
90 	struct max77620_therm_info *mtherm;
91 	int ret;
92 
93 	mtherm = devm_kzalloc(&pdev->dev, sizeof(*mtherm), GFP_KERNEL);
94 	if (!mtherm)
95 		return -ENOMEM;
96 
97 	mtherm->irq_tjalarm1 = platform_get_irq(pdev, 0);
98 	mtherm->irq_tjalarm2 = platform_get_irq(pdev, 1);
99 	if ((mtherm->irq_tjalarm1 < 0) || (mtherm->irq_tjalarm2 < 0)) {
100 		dev_err(&pdev->dev, "Alarm irq number not available\n");
101 		return -EINVAL;
102 	}
103 
104 	mtherm->dev = &pdev->dev;
105 	mtherm->rmap = dev_get_regmap(pdev->dev.parent, NULL);
106 	if (!mtherm->rmap) {
107 		dev_err(&pdev->dev, "Failed to get parent regmap\n");
108 		return -ENODEV;
109 	}
110 
111 	/*
112 	 * The reference taken to the parent's node which will be balanced on
113 	 * reprobe or on platform-device release.
114 	 */
115 	device_set_of_node_from_dev(&pdev->dev, pdev->dev.parent);
116 
117 	mtherm->tz_device = devm_thermal_of_zone_register(&pdev->dev, 0,
118 				mtherm, &max77620_thermal_ops);
119 	if (IS_ERR(mtherm->tz_device)) {
120 		ret = PTR_ERR(mtherm->tz_device);
121 		dev_err(&pdev->dev, "Failed to register thermal zone: %d\n",
122 			ret);
123 		return ret;
124 	}
125 
126 	ret = devm_request_threaded_irq(&pdev->dev, mtherm->irq_tjalarm1, NULL,
127 					max77620_thermal_irq,
128 					IRQF_ONESHOT | IRQF_SHARED,
129 					dev_name(&pdev->dev), mtherm);
130 	if (ret < 0) {
131 		dev_err(&pdev->dev, "Failed to request irq1: %d\n", ret);
132 		return ret;
133 	}
134 
135 	ret = devm_request_threaded_irq(&pdev->dev, mtherm->irq_tjalarm2, NULL,
136 					max77620_thermal_irq,
137 					IRQF_ONESHOT | IRQF_SHARED,
138 					dev_name(&pdev->dev), mtherm);
139 	if (ret < 0) {
140 		dev_err(&pdev->dev, "Failed to request irq2: %d\n", ret);
141 		return ret;
142 	}
143 
144 	platform_set_drvdata(pdev, mtherm);
145 
146 	return 0;
147 }
148 
149 static struct platform_device_id max77620_thermal_devtype[] = {
150 	{ .name = "max77620-thermal", },
151 	{},
152 };
153 MODULE_DEVICE_TABLE(platform, max77620_thermal_devtype);
154 
155 static struct platform_driver max77620_thermal_driver = {
156 	.driver = {
157 		.name = "max77620-thermal",
158 	},
159 	.probe = max77620_thermal_probe,
160 	.id_table = max77620_thermal_devtype,
161 };
162 
163 module_platform_driver(max77620_thermal_driver);
164 
165 MODULE_DESCRIPTION("Max77620 Junction temperature Thermal driver");
166 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
167 MODULE_AUTHOR("Mallikarjun Kasoju <mkasoju@nvidia.com>");
168 MODULE_LICENSE("GPL v2");
169