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_0:
  34         case PRID_REV_LOONGSON3A_R3_1:
  35                 reg = (reg & 0xffff)*731/0x4000 - 273;
  36                 break;
  37         }
  38         return (int)reg * 1000;
  39 }
  40
  41 static int nr_packages;
  42 static struct device *cpu_hwmon_dev;
  43
  44 static ssize_t get_hwmon_name(struct device *dev,
  45                         struct device_attribute *attr, char *buf);
  46 static SENSOR_DEVICE_ATTR(name, S_IRUGO, get_hwmon_name, NULL, 0);
  47
  48 static struct attribute *cpu_hwmon_attributes[] = {
  49         &sensor_dev_attr_name.dev_attr.attr,
  50         NULL
  51 };
  52
  53 /* Hwmon device attribute group */
  54 static struct attribute_group cpu_hwmon_attribute_group = {
  55         .attrs = cpu_hwmon_attributes,
  56 };
  57
  58 /* Hwmon device get name */
  59 static ssize_t get_hwmon_name(struct device *dev,
  60                         struct device_attribute *attr, char *buf)
  61 {
  62         return sprintf(buf, "cpu-hwmon\n");
  63 }
  64
  65 static ssize_t get_cpu_temp(struct device *dev,
  66                         struct device_attribute *attr, char *buf);
  67 static ssize_t cpu_temp_label(struct device *dev,
  68                         struct device_attribute *attr, char *buf);
  69
  70 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, get_cpu_temp, NULL, 1);
  71 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, cpu_temp_label, NULL, 1);
  72 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, get_cpu_temp, NULL, 2);
  73 static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, cpu_temp_label, NULL, 2);
  74 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, get_cpu_temp, NULL, 3);
  75 static SENSOR_DEVICE_ATTR(temp3_label, S_IRUGO, cpu_temp_label, NULL, 3);
  76 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, get_cpu_temp, NULL, 4);
  77 static SENSOR_DEVICE_ATTR(temp4_label, S_IRUGO, cpu_temp_label, NULL, 4);
  78
  79 static const struct attribute *hwmon_cputemp[4][3] = {
  80         {
  81                 &sensor_dev_attr_temp1_input.dev_attr.attr,
  82                 &sensor_dev_attr_temp1_label.dev_attr.attr,
  83                 NULL
  84         },
  85         {
  86                 &sensor_dev_attr_temp2_input.dev_attr.attr,
  87                 &sensor_dev_attr_temp2_label.dev_attr.attr,
  88                 NULL
  89         },
  90         {
  91                 &sensor_dev_attr_temp3_input.dev_attr.attr,
  92                 &sensor_dev_attr_temp3_label.dev_attr.attr,
  93                 NULL
  94         },
  95         {
  96                 &sensor_dev_attr_temp4_input.dev_attr.attr,
  97                 &sensor_dev_attr_temp4_label.dev_attr.attr,
  98                 NULL
  99         }
 100 };
 101
 102 static ssize_t cpu_temp_label(struct device *dev,
 103                         struct device_attribute *attr, char *buf)
 104 {
 105         int id = (to_sensor_dev_attr(attr))->index - 1;
 106         return sprintf(buf, "CPU %d Temperature\n", id);
 107 }
 108
 109 static ssize_t get_cpu_temp(struct device *dev,
 110                         struct device_attribute *attr, char *buf)
 111 {
 112         int id = (to_sensor_dev_attr(attr))->index - 1;
 113         int value = loongson3_cpu_temp(id);
 114         return sprintf(buf, "%d\n", value);
 115 }
 116
 117 static int create_sysfs_cputemp_files(struct kobject *kobj)
 118 {
 119         int i, ret = 0;
 120
 121         for (i=0; i<nr_packages; i++)
 122                 ret = sysfs_create_files(kobj, hwmon_cputemp[i]);
 123
 124         return ret;
 125 }
 126
 127 static void remove_sysfs_cputemp_files(struct kobject *kobj)
 128 {
 129         int i;
 130
 131         for (i=0; i<nr_packages; i++)
 132                 sysfs_remove_files(kobj, hwmon_cputemp[i]);
 133 }
 134
 135 #define CPU_THERMAL_THRESHOLD 90000
 136 static struct delayed_work thermal_work;
 137
 138 static void do_thermal_timer(struct work_struct *work)
 139 {
 140         int i, value, temp_max = 0;
 141
 142         for (i=0; i<nr_packages; i++) {
 143                 value = loongson3_cpu_temp(i);
 144                 if (value > temp_max)
 145                         temp_max = value;
 146         }
 147
 148         if (temp_max <= CPU_THERMAL_THRESHOLD)
 149                 schedule_delayed_work(&thermal_work, msecs_to_jiffies(5000));
 150         else
 151                 orderly_poweroff(true);
 152 }
 153
 154 static int __init loongson_hwmon_init(void)
 155 {
 156         int ret;
 157
 158         pr_info("Loongson Hwmon Enter...\n");
 159
 160         cpu_hwmon_dev = hwmon_device_register(NULL);
 161         if (IS_ERR(cpu_hwmon_dev)) {
 162                 ret = -ENOMEM;
 163                 pr_err("hwmon_device_register fail!\n");
 164                 goto fail_hwmon_device_register;
 165         }
 166
 167         nr_packages = loongson_sysconf.nr_cpus /
 168                 loongson_sysconf.cores_per_package;
 169
 170         ret = sysfs_create_group(&cpu_hwmon_dev->kobj,
 171                                 &cpu_hwmon_attribute_group);
 172         if (ret) {
 173                 pr_err("fail to create loongson hwmon!\n");
 174                 goto fail_sysfs_create_group_hwmon;
 175         }
 176
 177         ret = create_sysfs_cputemp_files(&cpu_hwmon_dev->kobj);
 178         if (ret) {
 179                 pr_err("fail to create cpu temperature interface!\n");
 180                 goto fail_create_sysfs_cputemp_files;
 181         }
 182
 183         INIT_DEFERRABLE_WORK(&thermal_work, do_thermal_timer);
 184         schedule_delayed_work(&thermal_work, msecs_to_jiffies(20000));
 185
 186         return ret;
 187
 188 fail_create_sysfs_cputemp_files:
 189         sysfs_remove_group(&cpu_hwmon_dev->kobj,
 190                                 &cpu_hwmon_attribute_group);
 191
 192 fail_sysfs_create_group_hwmon:
 193         hwmon_device_unregister(cpu_hwmon_dev);
 194
 195 fail_hwmon_device_register:
 196         return ret;
 197 }
 198
 199 static void __exit loongson_hwmon_exit(void)
 200 {
 201         cancel_delayed_work_sync(&thermal_work);
 202         remove_sysfs_cputemp_files(&cpu_hwmon_dev->kobj);
 203         sysfs_remove_group(&cpu_hwmon_dev->kobj,
 204                                 &cpu_hwmon_attribute_group);
 205         hwmon_device_unregister(cpu_hwmon_dev);
 206 }
 207
 208 module_init(loongson_hwmon_init);
 209 module_exit(loongson_hwmon_exit);
 210
 211 MODULE_AUTHOR("Yu Xiang <xiangy@lemote.com>");
 212 MODULE_AUTHOR("Huacai Chen <chenhc@lemote.com>");
 213 MODULE_DESCRIPTION("Loongson CPU Hwmon driver");
 214 MODULE_LICENSE("GPL");