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, 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
 40static int nr_packages;
 41static struct device *cpu_hwmon_dev;
 42
 43static ssize_t get_hwmon_name(struct device *dev,
 44			struct device_attribute *attr, char *buf);
 45static SENSOR_DEVICE_ATTR(name, S_IRUGO, get_hwmon_name, NULL, 0);
 46
 47static struct attribute *cpu_hwmon_attributes[] = {
 48	&sensor_dev_attr_name.dev_attr.attr,
 49	NULL
 50};
 51
 52/* Hwmon device attribute group */
 53static struct attribute_group cpu_hwmon_attribute_group = {
 54	.attrs = cpu_hwmon_attributes,
 55};
 56
 57/* Hwmon device get name */
 58static 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
 64static ssize_t get_cpu_temp(struct device *dev,
 65			struct device_attribute *attr, char *buf);
 66static ssize_t cpu_temp_label(struct device *dev,
 67			struct device_attribute *attr, char *buf);
 68
 69static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, get_cpu_temp, NULL, 1);
 70static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, cpu_temp_label, NULL, 1);
 71static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, get_cpu_temp, NULL, 2);
 72static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, cpu_temp_label, NULL, 2);
 73static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, get_cpu_temp, NULL, 3);
 74static SENSOR_DEVICE_ATTR(temp3_label, S_IRUGO, cpu_temp_label, NULL, 3);
 75static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, get_cpu_temp, NULL, 4);
 76static SENSOR_DEVICE_ATTR(temp4_label, S_IRUGO, cpu_temp_label, NULL, 4);
 77
 78static 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
101static 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
108static 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
116static 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
126static 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
135static struct delayed_work thermal_work;
136
137static 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
153static 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
187fail_create_sysfs_cputemp_files:
188	sysfs_remove_group(&cpu_hwmon_dev->kobj,
189				&cpu_hwmon_attribute_group);
190
191fail_sysfs_create_group_hwmon:
192	hwmon_device_unregister(cpu_hwmon_dev);
193
194fail_hwmon_device_register:
195	return ret;
196}
197
198static 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
207module_init(loongson_hwmon_init);
208module_exit(loongson_hwmon_exit);
209
210MODULE_AUTHOR("Yu Xiang <xiangy@lemote.com>");
211MODULE_AUTHOR("Huacai Chen <chenhc@lemote.com>");
212MODULE_DESCRIPTION("Loongson CPU Hwmon driver");
213MODULE_LICENSE("GPL");