drivers/platform/mips/cpu_hwmon.c

   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");