1 #include <linux/err.h>
2 #include <linux/module.h>
3 #include <linux/reboot.h>
4 #include <linux/jiffies.h>
5 #include <linux/hwmon.h>
6 #include <linux/hwmon-sysfs.h>
7 
8 #include <loongson.h>
9 #include <boot_param.h>
10 #include <loongson_hwmon.h>
11 
12 /*
13  * Loongson-3 series cpu has two sensors inside,
14  * each of them from 0 to 255,
15  * if more than 127, that is dangerous.
16  * here only provide sensor1 data, because it always hot than sensor0
17  */
18 int loongson3_cpu_temp(int cpu)
19 {
20 	u32 reg, prid_rev;
21 
22 	reg = LOONGSON_CHIPTEMP(cpu);
23 	prid_rev = read_c0_prid() & PRID_REV_MASK;
24 	switch (prid_rev) {
25 	case PRID_REV_LOONGSON3A_R1:
26 		reg = (reg >> 8) & 0xff;
27 		break;
28 	case PRID_REV_LOONGSON3A_R2:
29 	case PRID_REV_LOONGSON3B_R1:
30 	case PRID_REV_LOONGSON3B_R2:
31 		reg = ((reg >> 8) & 0xff) - 100;
32 		break;
33 	case PRID_REV_LOONGSON3A_R3_0:
34 	case PRID_REV_LOONGSON3A_R3_1:
35 		reg = (reg & 0xffff)*731/0x4000 - 273;
36 		break;
37 	}
38 	return (int)reg * 1000;
39 }
40 
41 static int nr_packages;
42 static struct device *cpu_hwmon_dev;
43 
44 static ssize_t get_hwmon_name(struct device *dev,
45 			struct device_attribute *attr, char *buf);
46 static SENSOR_DEVICE_ATTR(name, S_IRUGO, get_hwmon_name, NULL, 0);
47 
48 static struct attribute *cpu_hwmon_attributes[] = {
49 	&sensor_dev_attr_name.dev_attr.attr,
50 	NULL
51 };
52 
53 /* Hwmon device attribute group */
54 static struct attribute_group cpu_hwmon_attribute_group = {
55 	.attrs = cpu_hwmon_attributes,
56 };
57 
58 /* Hwmon device get name */
59 static ssize_t get_hwmon_name(struct device *dev,
60 			struct device_attribute *attr, char *buf)
61 {
62 	return sprintf(buf, "cpu-hwmon\n");
63 }
64 
65 static ssize_t get_cpu_temp(struct device *dev,
66 			struct device_attribute *attr, char *buf);
67 static ssize_t cpu_temp_label(struct device *dev,
68 			struct device_attribute *attr, char *buf);
69 
70 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, get_cpu_temp, NULL, 1);
71 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, cpu_temp_label, NULL, 1);
72 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, get_cpu_temp, NULL, 2);
73 static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, cpu_temp_label, NULL, 2);
74 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, get_cpu_temp, NULL, 3);
75 static SENSOR_DEVICE_ATTR(temp3_label, S_IRUGO, cpu_temp_label, NULL, 3);
76 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, get_cpu_temp, NULL, 4);
77 static SENSOR_DEVICE_ATTR(temp4_label, S_IRUGO, cpu_temp_label, NULL, 4);
78 
79 static const struct attribute *hwmon_cputemp[4][3] = {
80 	{
81 		&sensor_dev_attr_temp1_input.dev_attr.attr,
82 		&sensor_dev_attr_temp1_label.dev_attr.attr,
83 		NULL
84 	},
85 	{
86 		&sensor_dev_attr_temp2_input.dev_attr.attr,
87 		&sensor_dev_attr_temp2_label.dev_attr.attr,
88 		NULL
89 	},
90 	{
91 		&sensor_dev_attr_temp3_input.dev_attr.attr,
92 		&sensor_dev_attr_temp3_label.dev_attr.attr,
93 		NULL
94 	},
95 	{
96 		&sensor_dev_attr_temp4_input.dev_attr.attr,
97 		&sensor_dev_attr_temp4_label.dev_attr.attr,
98 		NULL
99 	}
100 };
101 
102 static ssize_t cpu_temp_label(struct device *dev,
103 			struct device_attribute *attr, char *buf)
104 {
105 	int id = (to_sensor_dev_attr(attr))->index - 1;
106 	return sprintf(buf, "CPU %d Temperature\n", id);
107 }
108 
109 static ssize_t get_cpu_temp(struct device *dev,
110 			struct device_attribute *attr, char *buf)
111 {
112 	int id = (to_sensor_dev_attr(attr))->index - 1;
113 	int value = loongson3_cpu_temp(id);
114 	return sprintf(buf, "%d\n", value);
115 }
116 
117 static int create_sysfs_cputemp_files(struct kobject *kobj)
118 {
119 	int i, ret = 0;
120 
121 	for (i=0; i<nr_packages; i++)
122 		ret = sysfs_create_files(kobj, hwmon_cputemp[i]);
123 
124 	return ret;
125 }
126 
127 static void remove_sysfs_cputemp_files(struct kobject *kobj)
128 {
129 	int i;
130 
131 	for (i=0; i<nr_packages; i++)
132 		sysfs_remove_files(kobj, hwmon_cputemp[i]);
133 }
134 
135 #define CPU_THERMAL_THRESHOLD 90000
136 static struct delayed_work thermal_work;
137 
138 static void do_thermal_timer(struct work_struct *work)
139 {
140 	int i, value, temp_max = 0;
141 
142 	for (i=0; i<nr_packages; i++) {
143 		value = loongson3_cpu_temp(i);
144 		if (value > temp_max)
145 			temp_max = value;
146 	}
147 
148 	if (temp_max <= CPU_THERMAL_THRESHOLD)
149 		schedule_delayed_work(&thermal_work, msecs_to_jiffies(5000));
150 	else
151 		orderly_poweroff(true);
152 }
153 
154 static int __init loongson_hwmon_init(void)
155 {
156 	int ret;
157 
158 	pr_info("Loongson Hwmon Enter...\n");
159 
160 	cpu_hwmon_dev = hwmon_device_register(NULL);
161 	if (IS_ERR(cpu_hwmon_dev)) {
162 		ret = -ENOMEM;
163 		pr_err("hwmon_device_register fail!\n");
164 		goto fail_hwmon_device_register;
165 	}
166 
167 	nr_packages = loongson_sysconf.nr_cpus /
168 		loongson_sysconf.cores_per_package;
169 
170 	ret = sysfs_create_group(&cpu_hwmon_dev->kobj,
171 				&cpu_hwmon_attribute_group);
172 	if (ret) {
173 		pr_err("fail to create loongson hwmon!\n");
174 		goto fail_sysfs_create_group_hwmon;
175 	}
176 
177 	ret = create_sysfs_cputemp_files(&cpu_hwmon_dev->kobj);
178 	if (ret) {
179 		pr_err("fail to create cpu temperature interface!\n");
180 		goto fail_create_sysfs_cputemp_files;
181 	}
182 
183 	INIT_DEFERRABLE_WORK(&thermal_work, do_thermal_timer);
184 	schedule_delayed_work(&thermal_work, msecs_to_jiffies(20000));
185 
186 	return ret;
187 
188 fail_create_sysfs_cputemp_files:
189 	sysfs_remove_group(&cpu_hwmon_dev->kobj,
190 				&cpu_hwmon_attribute_group);
191 
192 fail_sysfs_create_group_hwmon:
193 	hwmon_device_unregister(cpu_hwmon_dev);
194 
195 fail_hwmon_device_register:
196 	return ret;
197 }
198 
199 static void __exit loongson_hwmon_exit(void)
200 {
201 	cancel_delayed_work_sync(&thermal_work);
202 	remove_sysfs_cputemp_files(&cpu_hwmon_dev->kobj);
203 	sysfs_remove_group(&cpu_hwmon_dev->kobj,
204 				&cpu_hwmon_attribute_group);
205 	hwmon_device_unregister(cpu_hwmon_dev);
206 }
207 
208 module_init(loongson_hwmon_init);
209 module_exit(loongson_hwmon_exit);
210 
211 MODULE_AUTHOR("Yu Xiang <xiangy@lemote.com>");
212 MODULE_AUTHOR("Huacai Chen <chenhc@lemote.com>");
213 MODULE_DESCRIPTION("Loongson CPU Hwmon driver");
214 MODULE_LICENSE("GPL");
215