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 = 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 
67 static const struct thermal_zone_device_ops max77620_thermal_ops = {
68 	.get_temp = max77620_thermal_read_temp,
69 };
70 
71 static 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 
86 static 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 	platform_set_drvdata(pdev, mtherm);
143 
144 	return 0;
145 }
146 
147 static struct platform_device_id max77620_thermal_devtype[] = {
148 	{ .name = "max77620-thermal", },
149 	{},
150 };
151 MODULE_DEVICE_TABLE(platform, max77620_thermal_devtype);
152 
153 static struct platform_driver max77620_thermal_driver = {
154 	.driver = {
155 		.name = "max77620-thermal",
156 	},
157 	.probe = max77620_thermal_probe,
158 	.id_table = max77620_thermal_devtype,
159 };
160 
161 module_platform_driver(max77620_thermal_driver);
162 
163 MODULE_DESCRIPTION("Max77620 Junction temperature Thermal driver");
164 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
165 MODULE_AUTHOR("Mallikarjun Kasoju <mkasoju@nvidia.com>");
166 MODULE_LICENSE("GPL v2");
167