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 = 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
max77620_thermal_irq(int irq,void * data)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
max77620_thermal_probe(struct platform_device * pdev)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
