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 */
 18int loongson3_cpu_temp(int cpu)
 19{
 20	u32 reg;
 21
 22	reg = LOONGSON_CHIPTEMP(cpu);
 23	if ((read_c0_prid() & PRID_REV_MASK) == PRID_REV_LOONGSON3A_R1)
 24		reg = (reg >> 8) & 0xff;
 25	else
 26		reg = ((reg >> 8) & 0xff) - 100;
 27
 28	return (int)reg * 1000;
 29}
 30
 31static struct device *cpu_hwmon_dev;
 32
 33static ssize_t get_hwmon_name(struct device *dev,
 34			struct device_attribute *attr, char *buf);
 35static SENSOR_DEVICE_ATTR(name, S_IRUGO, get_hwmon_name, NULL, 0);
 36
 37static struct attribute *cpu_hwmon_attributes[] = {
 38	&sensor_dev_attr_name.dev_attr.attr,
 39	NULL
 40};
 41
 42/* Hwmon device attribute group */
 43static struct attribute_group cpu_hwmon_attribute_group = {
 44	.attrs = cpu_hwmon_attributes,
 45};
 46
 47/* Hwmon device get name */
 48static 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
 54static ssize_t get_cpu0_temp(struct device *dev,
 55			struct device_attribute *attr, char *buf);
 56static ssize_t get_cpu1_temp(struct device *dev,
 57			struct device_attribute *attr, char *buf);
 58static ssize_t cpu0_temp_label(struct device *dev,
 59			struct device_attribute *attr, char *buf);
 60static ssize_t cpu1_temp_label(struct device *dev,
 61			struct device_attribute *attr, char *buf);
 62
 63static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, get_cpu0_temp, NULL, 1);
 64static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, cpu0_temp_label, NULL, 1);
 65static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, get_cpu1_temp, NULL, 2);
 66static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, cpu1_temp_label, NULL, 2);
 67
 68static 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
 74static 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
 80static ssize_t cpu0_temp_label(struct device *dev,
 81			struct device_attribute *attr, char *buf)
 82{
 83	return sprintf(buf, "CPU 0 Temperature\n");
 84}
 85
 86static ssize_t cpu1_temp_label(struct device *dev,
 87			struct device_attribute *attr, char *buf)
 88{
 89	return sprintf(buf, "CPU 1 Temperature\n");
 90}
 91
 92static 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
 99static 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
106static 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
123sysfs_create_temp2_fail:
124	sysfs_remove_files(kobj, hwmon_cputemp1);
125
126sysfs_create_temp1_fail:
127	return -1;
128}
129
130static 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
139static struct delayed_work thermal_work;
140
141static 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
150static 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 temperature 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
181fail_create_sysfs_cputemp_files:
182	sysfs_remove_group(&cpu_hwmon_dev->kobj,
183				&cpu_hwmon_attribute_group);
184
185fail_sysfs_create_group_hwmon:
186	hwmon_device_unregister(cpu_hwmon_dev);
187
188fail_hwmon_device_register:
189	return ret;
190}
191
192static 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
201module_init(loongson_hwmon_init);
202module_exit(loongson_hwmon_exit);
203
204MODULE_AUTHOR("Yu Xiang <xiangy@lemote.com>");
205MODULE_AUTHOR("Huacai Chen <chenhc@lemote.com>");
206MODULE_DESCRIPTION("Loongson CPU Hwmon driver");
207MODULE_LICENSE("GPL");