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