drivers/staging/greybus/bundle.c

   1 /*
   2  * Greybus bundles
   3  *
   4  * Copyright 2014-2015 Google Inc.
   5  * Copyright 2014-2015 Linaro Ltd.
   6  *
   7  * Released under the GPLv2 only.
   8  */
   9
  10 #include "greybus.h"
  11
  12 static ssize_t bundle_class_show(struct device *dev,
  13                                  struct device_attribute *attr, char *buf)
  14 {
  15         struct gb_bundle *bundle = to_gb_bundle(dev);
  16
  17         return sprintf(buf, "0x%02x\n", bundle->class);
  18 }
  19 static DEVICE_ATTR_RO(bundle_class);
  20
  21 static ssize_t bundle_id_show(struct device *dev,
  22                               struct device_attribute *attr, char *buf)
  23 {
  24         struct gb_bundle *bundle = to_gb_bundle(dev);
  25
  26         return sprintf(buf, "%u\n", bundle->id);
  27 }
  28 static DEVICE_ATTR_RO(bundle_id);
  29
  30 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
  31                           char *buf)
  32 {
  33         struct gb_bundle *bundle = to_gb_bundle(dev);
  34
  35         if (bundle->state == NULL)
  36                 return sprintf(buf, "\n");
  37
  38         return sprintf(buf, "%s\n", bundle->state);
  39 }
  40
  41 static ssize_t state_store(struct device *dev, struct device_attribute *attr,
  42                            const char *buf, size_t size)
  43 {
  44         struct gb_bundle *bundle = to_gb_bundle(dev);
  45
  46         kfree(bundle->state);
  47         bundle->state = kstrdup(buf, GFP_KERNEL);
  48         if (!bundle->state)
  49                 return -ENOMEM;
  50
  51         /* Tell userspace that the file contents changed */
  52         sysfs_notify(&bundle->dev.kobj, NULL, "state");
  53
  54         return size;
  55 }
  56 static DEVICE_ATTR_RW(state);
  57
  58
  59 static struct attribute *bundle_attrs[] = {
  60         &dev_attr_bundle_class.attr,
  61         &dev_attr_bundle_id.attr,
  62         &dev_attr_state.attr,
  63         NULL,
  64 };
  65
  66 ATTRIBUTE_GROUPS(bundle);
  67
  68 static struct gb_bundle *gb_bundle_find(struct gb_interface *intf,
  69                                                         u8 bundle_id)
  70 {
  71         struct gb_bundle *bundle;
  72
  73         list_for_each_entry(bundle, &intf->bundles, links) {
  74                 if (bundle->id == bundle_id)
  75                         return bundle;
  76         }
  77
  78         return NULL;
  79 }
  80
  81 static void gb_bundle_release(struct device *dev)
  82 {
  83         struct gb_bundle *bundle = to_gb_bundle(dev);
  84         struct gb_connection *connection;
  85         struct gb_connection *tmp;
  86
  87         list_for_each_entry_safe(connection, tmp, &bundle->connections,
  88                                                                 bundle_links) {
  89                 gb_connection_destroy(connection);
  90         }
  91
  92         kfree(bundle->state);
  93         kfree(bundle);
  94 }
  95
  96 struct device_type greybus_bundle_type = {
  97         .name =         "greybus_bundle",
  98         .release =      gb_bundle_release,
  99 };
 100
 101 /*
 102  * Create a gb_bundle structure to represent a discovered
 103  * bundle.  Returns a pointer to the new bundle or a null
 104  * pointer if a failure occurs due to memory exhaustion.
 105  */
 106 struct gb_bundle *gb_bundle_create(struct gb_interface *intf, u8 bundle_id,
 107                                    u8 class)
 108 {
 109         struct gb_bundle *bundle;
 110
 111         /*
 112          * Reject any attempt to reuse a bundle id.  We initialize
 113          * these serially, so there's no need to worry about keeping
 114          * the interface bundle list locked here.
 115          */
 116         if (gb_bundle_find(intf, bundle_id)) {
 117                 dev_err(&intf->dev, "duplicate bundle id %u\n", bundle_id);
 118                 return NULL;
 119         }
 120
 121         bundle = kzalloc(sizeof(*bundle), GFP_KERNEL);
 122         if (!bundle)
 123                 return NULL;
 124
 125         bundle->intf = intf;
 126         bundle->id = bundle_id;
 127         bundle->class = class;
 128         INIT_LIST_HEAD(&bundle->connections);
 129
 130         bundle->dev.parent = &intf->dev;
 131         bundle->dev.bus = &greybus_bus_type;
 132         bundle->dev.type = &greybus_bundle_type;
 133         bundle->dev.groups = bundle_groups;
 134         device_initialize(&bundle->dev);
 135         dev_set_name(&bundle->dev, "%s.%d", dev_name(&intf->dev), bundle_id);
 136
 137         list_add(&bundle->links, &intf->bundles);
 138
 139         return bundle;
 140 }
 141
 142 int gb_bundle_add(struct gb_bundle *bundle)
 143 {
 144         int ret;
 145
 146         ret = device_add(&bundle->dev);
 147         if (ret) {
 148                 dev_err(&bundle->dev, "failed to register bundle: %d\n", ret);
 149                 return ret;
 150         }
 151
 152         return 0;
 153 }
 154
 155 /*
 156  * Tear down a previously set up bundle.
 157  */
 158 void gb_bundle_destroy(struct gb_bundle *bundle)
 159 {
 160         if (device_is_registered(&bundle->dev))
 161                 device_del(&bundle->dev);
 162
 163         list_del(&bundle->links);
 164
 165         put_device(&bundle->dev);
 166 }