1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/err.h>
3 #include <linux/module.h>
4 #include <linux/reboot.h>
5 #include <linux/jiffies.h>
6 #include <linux/hwmon.h>
7 #include <linux/hwmon-sysfs.h>
8 
9 #include <loongson.h>
10 #include <boot_param.h>
11 #include <loongson_hwmon.h>
12 #include <loongson_regs.h>
13 
14 static int csr_temp_enable;
15 
16 /*
17  * Loongson-3 series cpu has two sensors inside,
18  * each of them from 0 to 255,
19  * if more than 127, that is dangerous.
20  * here only provide sensor1 data, because it always hot than sensor0
21  */
22 int loongson3_cpu_temp(int cpu)
23 {
24 	u32 reg, prid_rev;
25 
26 	if (csr_temp_enable) {
27 		reg = (csr_readl(LOONGSON_CSR_CPUTEMP) & 0xff);
28 		goto out;
29 	}
30 
31 	reg = LOONGSON_CHIPTEMP(cpu);
32 	prid_rev = read_c0_prid() & PRID_REV_MASK;
33 
34 	switch (prid_rev) {
35 	case PRID_REV_LOONGSON3A_R1:
36 		reg = (reg >> 8) & 0xff;
37 		break;
38 	case PRID_REV_LOONGSON3B_R1:
39 	case PRID_REV_LOONGSON3B_R2:
40 	case PRID_REV_LOONGSON3A_R2_0:
41 	case PRID_REV_LOONGSON3A_R2_1:
42 		reg = ((reg >> 8) & 0xff) - 100;
43 		break;
44 	case PRID_REV_LOONGSON3A_R3_0:
45 	case PRID_REV_LOONGSON3A_R3_1:
46 	default:
47 		reg = (reg & 0xffff) * 731 / 0x4000 - 273;
48 		break;
49 	}
50 
51 out:
52 	return (int)reg * 1000;
53 }
54 
55 static int nr_packages;
56 static struct device *cpu_hwmon_dev;
57 
58 static ssize_t cpu_temp_label(struct device *dev,
59 			struct device_attribute *attr, char *buf)
60 {
61 	int id = (to_sensor_dev_attr(attr))->index - 1;
62 
63 	return sprintf(buf, "CPU %d Temperature\n", id);
64 }
65 
66 static ssize_t get_cpu_temp(struct device *dev,
67 			struct device_attribute *attr, char *buf)
68 {
69 	int id = (to_sensor_dev_attr(attr))->index - 1;
70 	int value = loongson3_cpu_temp(id);
71 
72 	return sprintf(buf, "%d\n", value);
73 }
74 
75 static SENSOR_DEVICE_ATTR(temp1_input, 0444, get_cpu_temp, NULL, 1);
76 static SENSOR_DEVICE_ATTR(temp1_label, 0444, cpu_temp_label, NULL, 1);
77 static SENSOR_DEVICE_ATTR(temp2_input, 0444, get_cpu_temp, NULL, 2);
78 static SENSOR_DEVICE_ATTR(temp2_label, 0444, cpu_temp_label, NULL, 2);
79 static SENSOR_DEVICE_ATTR(temp3_input, 0444, get_cpu_temp, NULL, 3);
80 static SENSOR_DEVICE_ATTR(temp3_label, 0444, cpu_temp_label, NULL, 3);
81 static SENSOR_DEVICE_ATTR(temp4_input, 0444, get_cpu_temp, NULL, 4);
82 static SENSOR_DEVICE_ATTR(temp4_label, 0444, cpu_temp_label, NULL, 4);
83 
84 static struct attribute *cpu_hwmon_attributes[] = {
85 	&sensor_dev_attr_temp1_input.dev_attr.attr,
86 	&sensor_dev_attr_temp1_label.dev_attr.attr,
87 	&sensor_dev_attr_temp2_input.dev_attr.attr,
88 	&sensor_dev_attr_temp2_label.dev_attr.attr,
89 	&sensor_dev_attr_temp3_input.dev_attr.attr,
90 	&sensor_dev_attr_temp3_label.dev_attr.attr,
91 	&sensor_dev_attr_temp4_input.dev_attr.attr,
92 	&sensor_dev_attr_temp4_label.dev_attr.attr,
93 	NULL
94 };
95 
96 static umode_t cpu_hwmon_is_visible(struct kobject *kobj,
97 				    struct attribute *attr, int i)
98 {
99 	int id = i / 2;
100 
101 	if (id < nr_packages)
102 		return attr->mode;
103 	return 0;
104 }
105 
106 static struct attribute_group cpu_hwmon_group = {
107 	.attrs = cpu_hwmon_attributes,
108 	.is_visible = cpu_hwmon_is_visible,
109 };
110 
111 static const struct attribute_group *cpu_hwmon_groups[] = {
112 	&cpu_hwmon_group,
113 	NULL
114 };
115 
116 #define CPU_THERMAL_THRESHOLD 90000
117 static struct delayed_work thermal_work;
118 
119 static void do_thermal_timer(struct work_struct *work)
120 {
121 	int i, value;
122 
123 	for (i = 0; i < nr_packages; i++) {
124 		value = loongson3_cpu_temp(i);
125 		if (value > CPU_THERMAL_THRESHOLD) {
126 			pr_emerg("Power off due to high temp: %d\n", value);
127 			orderly_poweroff(true);
128 		}
129 	}
130 
131 	schedule_delayed_work(&thermal_work, msecs_to_jiffies(5000));
132 }
133 
134 static int __init loongson_hwmon_init(void)
135 {
136 	pr_info("Loongson Hwmon Enter...\n");
137 
138 	if (cpu_has_csr())
139 		csr_temp_enable = csr_readl(LOONGSON_CSR_FEATURES) &
140 				  LOONGSON_CSRF_TEMP;
141 
142 	if (!csr_temp_enable && !loongson_chiptemp[0])
143 		return -ENODEV;
144 
145 	nr_packages = loongson_sysconf.nr_cpus /
146 		loongson_sysconf.cores_per_package;
147 
148 	cpu_hwmon_dev = hwmon_device_register_with_groups(NULL, "cpu_hwmon",
149 							  NULL, cpu_hwmon_groups);
150 	if (IS_ERR(cpu_hwmon_dev)) {
151 		pr_err("hwmon_device_register fail!\n");
152 		return PTR_ERR(cpu_hwmon_dev);
153 	}
154 
155 	INIT_DEFERRABLE_WORK(&thermal_work, do_thermal_timer);
156 	schedule_delayed_work(&thermal_work, msecs_to_jiffies(20000));
157 
158 	return 0;
159 }
160 
161 static void __exit loongson_hwmon_exit(void)
162 {
163 	cancel_delayed_work_sync(&thermal_work);
164 	hwmon_device_unregister(cpu_hwmon_dev);
165 }
166 
167 module_init(loongson_hwmon_init);
168 module_exit(loongson_hwmon_exit);
169 
170 MODULE_AUTHOR("Yu Xiang <xiangy@lemote.com>");
171 MODULE_AUTHOR("Huacai Chen <chenhc@lemote.com>");
172 MODULE_DESCRIPTION("Loongson CPU Hwmon driver");
173 MODULE_LICENSE("GPL");
174