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
max77620_thermal_read_temp(struct thermal_zone_device * tz,int * temp)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
max77620_thermal_irq(int irq,void * data)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
max77620_thermal_probe(struct platform_device * pdev)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 return 0;
143 }
144
145 static struct platform_device_id max77620_thermal_devtype[] = {
146 { .name = "max77620-thermal", },
147 {},
148 };
149 MODULE_DEVICE_TABLE(platform, max77620_thermal_devtype);
150
151 static 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
159 module_platform_driver(max77620_thermal_driver);
160
161 MODULE_DESCRIPTION("Max77620 Junction temperature Thermal driver");
162 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
163 MODULE_AUTHOR("Mallikarjun Kasoju <mkasoju@nvidia.com>");
164 MODULE_LICENSE("GPL v2");
165