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;
21 
22 	reg = LOONGSON_CHIPTEMP(cpu);
23 	if (loongson_sysconf.cputype == Loongson_3A)
24 		reg = (reg >> 8) & 0xff;
25 	else if (loongson_sysconf.cputype == Loongson_3B)
26 		reg = ((reg >> 8) & 0xff) - 100;
27 
28 	return (int)reg * 1000;
29 }
30 
31 static struct device *cpu_hwmon_dev;
32 
33 static ssize_t get_hwmon_name(struct device *dev,
34 			struct device_attribute *attr, char *buf);
35 static SENSOR_DEVICE_ATTR(name, S_IRUGO, get_hwmon_name, NULL, 0);
36 
37 static struct attribute *cpu_hwmon_attributes[] = {
38 	&sensor_dev_attr_name.dev_attr.attr,
39 	NULL
40 };
41 
42 /* Hwmon device attribute group */
43 static struct attribute_group cpu_hwmon_attribute_group = {
44 	.attrs = cpu_hwmon_attributes,
45 };
46 
47 /* Hwmon device get name */
48 static ssize_t get_hwmon_name(struct device *dev,
49 			struct device_attribute *attr, char *buf)
50 {
51 	return sprintf(buf, "cpu-hwmon\n");
52 }
53 
54 static ssize_t get_cpu0_temp(struct device *dev,
55 			struct device_attribute *attr, char *buf);
56 static ssize_t get_cpu1_temp(struct device *dev,
57 			struct device_attribute *attr, char *buf);
58 static ssize_t cpu0_temp_label(struct device *dev,
59 			struct device_attribute *attr, char *buf);
60 static ssize_t cpu1_temp_label(struct device *dev,
61 			struct device_attribute *attr, char *buf);
62 
63 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, get_cpu0_temp, NULL, 1);
64 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, cpu0_temp_label, NULL, 1);
65 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, get_cpu1_temp, NULL, 2);
66 static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, cpu1_temp_label, NULL, 2);
67 
68 static const struct attribute *hwmon_cputemp1[] = {
69 	&sensor_dev_attr_temp1_input.dev_attr.attr,
70 	&sensor_dev_attr_temp1_label.dev_attr.attr,
71 	NULL
72 };
73 
74 static const struct attribute *hwmon_cputemp2[] = {
75 	&sensor_dev_attr_temp2_input.dev_attr.attr,
76 	&sensor_dev_attr_temp2_label.dev_attr.attr,
77 	NULL
78 };
79 
80 static ssize_t cpu0_temp_label(struct device *dev,
81 			struct device_attribute *attr, char *buf)
82 {
83 	return sprintf(buf, "CPU 0 Temprature\n");
84 }
85 
86 static ssize_t cpu1_temp_label(struct device *dev,
87 			struct device_attribute *attr, char *buf)
88 {
89 	return sprintf(buf, "CPU 1 Temprature\n");
90 }
91 
92 static ssize_t get_cpu0_temp(struct device *dev,
93 			struct device_attribute *attr, char *buf)
94 {
95 	int value = loongson3_cpu_temp(0);
96 	return sprintf(buf, "%d\n", value);
97 }
98 
99 static ssize_t get_cpu1_temp(struct device *dev,
100 			struct device_attribute *attr, char *buf)
101 {
102 	int value = loongson3_cpu_temp(1);
103 	return sprintf(buf, "%d\n", value);
104 }
105 
106 static int create_sysfs_cputemp_files(struct kobject *kobj)
107 {
108 	int ret;
109 
110 	ret = sysfs_create_files(kobj, hwmon_cputemp1);
111 	if (ret)
112 		goto sysfs_create_temp1_fail;
113 
114 	if (loongson_sysconf.nr_cpus <= loongson_sysconf.cores_per_package)
115 		return 0;
116 
117 	ret = sysfs_create_files(kobj, hwmon_cputemp2);
118 	if (ret)
119 		goto sysfs_create_temp2_fail;
120 
121 	return 0;
122 
123 sysfs_create_temp2_fail:
124 	sysfs_remove_files(kobj, hwmon_cputemp1);
125 
126 sysfs_create_temp1_fail:
127 	return -1;
128 }
129 
130 static void remove_sysfs_cputemp_files(struct kobject *kobj)
131 {
132 	sysfs_remove_files(&cpu_hwmon_dev->kobj, hwmon_cputemp1);
133 
134 	if (loongson_sysconf.nr_cpus > loongson_sysconf.cores_per_package)
135 		sysfs_remove_files(&cpu_hwmon_dev->kobj, hwmon_cputemp2);
136 }
137 
138 #define CPU_THERMAL_THRESHOLD 90000
139 static struct delayed_work thermal_work;
140 
141 static void do_thermal_timer(struct work_struct *work)
142 {
143 	int value = loongson3_cpu_temp(0);
144 	if (value <= CPU_THERMAL_THRESHOLD)
145 		schedule_delayed_work(&thermal_work, msecs_to_jiffies(5000));
146 	else
147 		orderly_poweroff(true);
148 }
149 
150 static int __init loongson_hwmon_init(void)
151 {
152 	int ret;
153 
154 	pr_info("Loongson Hwmon Enter...\n");
155 
156 	cpu_hwmon_dev = hwmon_device_register(NULL);
157 	if (IS_ERR(cpu_hwmon_dev)) {
158 		ret = -ENOMEM;
159 		pr_err("hwmon_device_register fail!\n");
160 		goto fail_hwmon_device_register;
161 	}
162 
163 	ret = sysfs_create_group(&cpu_hwmon_dev->kobj,
164 				&cpu_hwmon_attribute_group);
165 	if (ret) {
166 		pr_err("fail to create loongson hwmon!\n");
167 		goto fail_sysfs_create_group_hwmon;
168 	}
169 
170 	ret = create_sysfs_cputemp_files(&cpu_hwmon_dev->kobj);
171 	if (ret) {
172 		pr_err("fail to create cpu temprature interface!\n");
173 		goto fail_create_sysfs_cputemp_files;
174 	}
175 
176 	INIT_DEFERRABLE_WORK(&thermal_work, do_thermal_timer);
177 	schedule_delayed_work(&thermal_work, msecs_to_jiffies(20000));
178 
179 	return ret;
180 
181 fail_create_sysfs_cputemp_files:
182 	sysfs_remove_group(&cpu_hwmon_dev->kobj,
183 				&cpu_hwmon_attribute_group);
184 
185 fail_sysfs_create_group_hwmon:
186 	hwmon_device_unregister(cpu_hwmon_dev);
187 
188 fail_hwmon_device_register:
189 	return ret;
190 }
191 
192 static void __exit loongson_hwmon_exit(void)
193 {
194 	cancel_delayed_work_sync(&thermal_work);
195 	remove_sysfs_cputemp_files(&cpu_hwmon_dev->kobj);
196 	sysfs_remove_group(&cpu_hwmon_dev->kobj,
197 				&cpu_hwmon_attribute_group);
198 	hwmon_device_unregister(cpu_hwmon_dev);
199 }
200 
201 module_init(loongson_hwmon_init);
202 module_exit(loongson_hwmon_exit);
203 
204 MODULE_AUTHOR("Yu Xiang <xiangy@lemote.com>");
205 MODULE_AUTHOR("Huacai Chen <chenhc@lemote.com>");
206 MODULE_DESCRIPTION("Loongson CPU Hwmon driver");
207 MODULE_LICENSE("GPL");
208