arch/powerpc/platforms/powernv/opal-sensor-groups.c

   1 /*
   2  * PowerNV OPAL Sensor-groups interface
   3  *
   4  * Copyright 2017 IBM Corp.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #define pr_fmt(fmt)     "opal-sensor-groups: " fmt
  13
  14 #include <linux/of.h>
  15 #include <linux/kobject.h>
  16 #include <linux/slab.h>
  17
  18 #include <asm/opal.h>
  19
  20 DEFINE_MUTEX(sg_mutex);
  21
  22 static struct kobject *sg_kobj;
  23
  24 struct sg_attr {
  25         u32 handle;
  26         struct kobj_attribute attr;
  27 };
  28
  29 static struct sensor_group {
  30         char name[20];
  31         struct attribute_group sg;
  32         struct sg_attr *sgattrs;
  33 } *sgs;
  34
  35 static ssize_t sg_store(struct kobject *kobj, struct kobj_attribute *attr,
  36                         const char *buf, size_t count)
  37 {
  38         struct sg_attr *sattr = container_of(attr, struct sg_attr, attr);
  39         struct opal_msg msg;
  40         u32 data;
  41         int ret, token;
  42
  43         ret = kstrtoint(buf, 0, &data);
  44         if (ret)
  45                 return ret;
  46
  47         if (data != 1)
  48                 return -EINVAL;
  49
  50         token = opal_async_get_token_interruptible();
  51         if (token < 0) {
  52                 pr_devel("Failed to get token\n");
  53                 return token;
  54         }
  55
  56         ret = mutex_lock_interruptible(&sg_mutex);
  57         if (ret)
  58                 goto out_token;
  59
  60         ret = opal_sensor_group_clear(sattr->handle, token);
  61         switch (ret) {
  62         case OPAL_ASYNC_COMPLETION:
  63                 ret = opal_async_wait_response(token, &msg);
  64                 if (ret) {
  65                         pr_devel("Failed to wait for the async response\n");
  66                         ret = -EIO;
  67                         goto out;
  68                 }
  69                 ret = opal_error_code(opal_get_async_rc(msg));
  70                 if (!ret)
  71                         ret = count;
  72                 break;
  73         case OPAL_SUCCESS:
  74                 ret = count;
  75                 break;
  76         default:
  77                 ret = opal_error_code(ret);
  78         }
  79
  80 out:
  81         mutex_unlock(&sg_mutex);
  82 out_token:
  83         opal_async_release_token(token);
  84         return ret;
  85 }
  86
  87 static struct sg_ops_info {
  88         int opal_no;
  89         const char *attr_name;
  90         ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
  91                         const char *buf, size_t count);
  92 } ops_info[] = {
  93         { OPAL_SENSOR_GROUP_CLEAR, "clear", sg_store },
  94 };
  95
  96 static void add_attr(int handle, struct sg_attr *attr, int index)
  97 {
  98         attr->handle = handle;
  99         sysfs_attr_init(&attr->attr.attr);
 100         attr->attr.attr.name = ops_info[index].attr_name;
 101         attr->attr.attr.mode = 0220;
 102         attr->attr.store = ops_info[index].store;
 103 }
 104
 105 static int add_attr_group(const __be32 *ops, int len, struct sensor_group *sg,
 106                            u32 handle)
 107 {
 108         int i, j;
 109         int count = 0;
 110
 111         for (i = 0; i < len; i++)
 112                 for (j = 0; j < ARRAY_SIZE(ops_info); j++)
 113                         if (be32_to_cpu(ops[i]) == ops_info[j].opal_no) {
 114                                 add_attr(handle, &sg->sgattrs[count], j);
 115                                 sg->sg.attrs[count] =
 116                                         &sg->sgattrs[count].attr.attr;
 117                                 count++;
 118                         }
 119
 120         return sysfs_create_group(sg_kobj, &sg->sg);
 121 }
 122
 123 static int get_nr_attrs(const __be32 *ops, int len)
 124 {
 125         int i, j;
 126         int nr_attrs = 0;
 127
 128         for (i = 0; i < len; i++)
 129                 for (j = 0; j < ARRAY_SIZE(ops_info); j++)
 130                         if (be32_to_cpu(ops[i]) == ops_info[j].opal_no)
 131                                 nr_attrs++;
 132
 133         return nr_attrs;
 134 }
 135
 136 void __init opal_sensor_groups_init(void)
 137 {
 138         struct device_node *sg, *node;
 139         int i = 0;
 140
 141         sg = of_find_compatible_node(NULL, NULL, "ibm,opal-sensor-group");
 142         if (!sg) {
 143                 pr_devel("Sensor groups node not found\n");
 144                 return;
 145         }
 146
 147         sgs = kcalloc(of_get_child_count(sg), sizeof(*sgs), GFP_KERNEL);
 148         if (!sgs)
 149                 return;
 150
 151         sg_kobj = kobject_create_and_add("sensor_groups", opal_kobj);
 152         if (!sg_kobj) {
 153                 pr_warn("Failed to create sensor group kobject\n");
 154                 goto out_sgs;
 155         }
 156
 157         for_each_child_of_node(sg, node) {
 158                 const __be32 *ops;
 159                 u32 sgid, len, nr_attrs, chipid;
 160
 161                 ops = of_get_property(node, "ops", &len);
 162                 if (!ops)
 163                         continue;
 164
 165                 nr_attrs = get_nr_attrs(ops, len);
 166                 if (!nr_attrs)
 167                         continue;
 168
 169                 sgs[i].sgattrs = kcalloc(nr_attrs, sizeof(struct sg_attr),
 170                                          GFP_KERNEL);
 171                 if (!sgs[i].sgattrs)
 172                         goto out_sgs_sgattrs;
 173
 174                 sgs[i].sg.attrs = kcalloc(nr_attrs + 1,
 175                                           sizeof(struct attribute *),
 176                                           GFP_KERNEL);
 177
 178                 if (!sgs[i].sg.attrs) {
 179                         kfree(sgs[i].sgattrs);
 180                         goto out_sgs_sgattrs;
 181                 }
 182
 183                 if (of_property_read_u32(node, "sensor-group-id", &sgid)) {
 184                         pr_warn("sensor-group-id property not found\n");
 185                         goto out_sgs_sgattrs;
 186                 }
 187
 188                 if (!of_property_read_u32(node, "ibm,chip-id", &chipid))
 189                         sprintf(sgs[i].name, "%s%d", node->name, chipid);
 190                 else
 191                         sprintf(sgs[i].name, "%s", node->name);
 192
 193                 sgs[i].sg.name = sgs[i].name;
 194                 if (add_attr_group(ops, len, &sgs[i], sgid)) {
 195                         pr_warn("Failed to create sensor attribute group %s\n",
 196                                 sgs[i].sg.name);
 197                         goto out_sgs_sgattrs;
 198                 }
 199                 i++;
 200         }
 201
 202         return;
 203
 204 out_sgs_sgattrs:
 205         while (--i >= 0) {
 206                 kfree(sgs[i].sgattrs);
 207                 kfree(sgs[i].sg.attrs);
 208         }
 209         kobject_put(sg_kobj);
 210 out_sgs:
 211         kfree(sgs);
 212 }