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 #include "greybus_trace.h"
  12
  13 static ssize_t bundle_class_show(struct device *dev,
  14                                  struct device_attribute *attr, char *buf)
  15 {
  16         struct gb_bundle *bundle = to_gb_bundle(dev);
  17
  18         return sprintf(buf, "0x%02x\n", bundle->class);
  19 }
  20 static DEVICE_ATTR_RO(bundle_class);
  21
  22 static ssize_t bundle_id_show(struct device *dev,
  23                               struct device_attribute *attr, char *buf)
  24 {
  25         struct gb_bundle *bundle = to_gb_bundle(dev);
  26
  27         return sprintf(buf, "%u\n", bundle->id);
  28 }
  29 static DEVICE_ATTR_RO(bundle_id);
  30
  31 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
  32                           char *buf)
  33 {
  34         struct gb_bundle *bundle = to_gb_bundle(dev);
  35
  36         if (bundle->state == NULL)
  37                 return sprintf(buf, "\n");
  38
  39         return sprintf(buf, "%s\n", bundle->state);
  40 }
  41
  42 static ssize_t state_store(struct device *dev, struct device_attribute *attr,
  43                            const char *buf, size_t size)
  44 {
  45         struct gb_bundle *bundle = to_gb_bundle(dev);
  46
  47         kfree(bundle->state);
  48         bundle->state = kstrdup(buf, GFP_KERNEL);
  49         if (!bundle->state)
  50                 return -ENOMEM;
  51
  52         /* Tell userspace that the file contents changed */
  53         sysfs_notify(&bundle->dev.kobj, NULL, "state");
  54
  55         return size;
  56 }
  57 static DEVICE_ATTR_RW(state);
  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
  85         trace_gb_bundle_release(bundle);
  86
  87         kfree(bundle->state);
  88         kfree(bundle->cport_desc);
  89         kfree(bundle);
  90 }
  91
  92 #ifdef CONFIG_PM
  93 static void gb_bundle_disable_all_connections(struct gb_bundle *bundle)
  94 {
  95         struct gb_connection *connection;
  96
  97         list_for_each_entry(connection, &bundle->connections, bundle_links)
  98                 gb_connection_disable(connection);
  99 }
 100
 101 static void gb_bundle_enable_all_connections(struct gb_bundle *bundle)
 102 {
 103         struct gb_connection *connection;
 104
 105         list_for_each_entry(connection, &bundle->connections, bundle_links)
 106                 gb_connection_enable(connection);
 107 }
 108
 109 static int gb_bundle_suspend(struct device *dev)
 110 {
 111         struct gb_bundle *bundle = to_gb_bundle(dev);
 112         const struct dev_pm_ops *pm = dev->driver->pm;
 113         int ret;
 114
 115         if (pm && pm->runtime_suspend) {
 116                 ret = pm->runtime_suspend(&bundle->dev);
 117                 if (ret)
 118                         return ret;
 119         } else {
 120                 gb_bundle_disable_all_connections(bundle);
 121         }
 122
 123         ret = gb_control_bundle_suspend(bundle->intf->control, bundle->id);
 124         if (ret) {
 125                 if (pm && pm->runtime_resume)
 126                         ret = pm->runtime_resume(dev);
 127                 else
 128                         gb_bundle_enable_all_connections(bundle);
 129
 130                 return ret;
 131         }
 132
 133         return 0;
 134 }
 135
 136 static int gb_bundle_resume(struct device *dev)
 137 {
 138         struct gb_bundle *bundle = to_gb_bundle(dev);
 139         const struct dev_pm_ops *pm = dev->driver->pm;
 140         int ret;
 141
 142         ret = gb_control_bundle_resume(bundle->intf->control, bundle->id);
 143         if (ret)
 144                 return ret;
 145
 146         if (pm && pm->runtime_resume) {
 147                 ret = pm->runtime_resume(dev);
 148                 if (ret)
 149                         return ret;
 150         } else {
 151                 gb_bundle_enable_all_connections(bundle);
 152         }
 153
 154         return 0;
 155 }
 156
 157 static int gb_bundle_idle(struct device *dev)
 158 {
 159         pm_runtime_mark_last_busy(dev);
 160         pm_request_autosuspend(dev);
 161
 162         return 0;
 163 }
 164 #endif
 165
 166 static const struct dev_pm_ops gb_bundle_pm_ops = {
 167         SET_RUNTIME_PM_OPS(gb_bundle_suspend, gb_bundle_resume, gb_bundle_idle)
 168 };
 169
 170 struct device_type greybus_bundle_type = {
 171         .name =         "greybus_bundle",
 172         .release =      gb_bundle_release,
 173         .pm =           &gb_bundle_pm_ops,
 174 };
 175
 176 /*
 177  * Create a gb_bundle structure to represent a discovered
 178  * bundle.  Returns a pointer to the new bundle or a null
 179  * pointer if a failure occurs due to memory exhaustion.
 180  */
 181 struct gb_bundle *gb_bundle_create(struct gb_interface *intf, u8 bundle_id,
 182                                    u8 class)
 183 {
 184         struct gb_bundle *bundle;
 185
 186         if (bundle_id == BUNDLE_ID_NONE) {
 187                 dev_err(&intf->dev, "can't use bundle id %u\n", bundle_id);
 188                 return NULL;
 189         }
 190
 191         /*
 192          * Reject any attempt to reuse a bundle id.  We initialize
 193          * these serially, so there's no need to worry about keeping
 194          * the interface bundle list locked here.
 195          */
 196         if (gb_bundle_find(intf, bundle_id)) {
 197                 dev_err(&intf->dev, "duplicate bundle id %u\n", bundle_id);
 198                 return NULL;
 199         }
 200
 201         bundle = kzalloc(sizeof(*bundle), GFP_KERNEL);
 202         if (!bundle)
 203                 return NULL;
 204
 205         bundle->intf = intf;
 206         bundle->id = bundle_id;
 207         bundle->class = class;
 208         INIT_LIST_HEAD(&bundle->connections);
 209
 210         bundle->dev.parent = &intf->dev;
 211         bundle->dev.bus = &greybus_bus_type;
 212         bundle->dev.type = &greybus_bundle_type;
 213         bundle->dev.groups = bundle_groups;
 214         bundle->dev.dma_mask = intf->dev.dma_mask;
 215         device_initialize(&bundle->dev);
 216         dev_set_name(&bundle->dev, "%s.%d", dev_name(&intf->dev), bundle_id);
 217
 218         list_add(&bundle->links, &intf->bundles);
 219
 220         trace_gb_bundle_create(bundle);
 221
 222         return bundle;
 223 }
 224
 225 int gb_bundle_add(struct gb_bundle *bundle)
 226 {
 227         int ret;
 228
 229         ret = device_add(&bundle->dev);
 230         if (ret) {
 231                 dev_err(&bundle->dev, "failed to register bundle: %d\n", ret);
 232                 return ret;
 233         }
 234
 235         trace_gb_bundle_add(bundle);
 236
 237         return 0;
 238 }
 239
 240 /*
 241  * Tear down a previously set up bundle.
 242  */
 243 void gb_bundle_destroy(struct gb_bundle *bundle)
 244 {
 245         trace_gb_bundle_destroy(bundle);
 246
 247         if (device_is_registered(&bundle->dev))
 248                 device_del(&bundle->dev);
 249
 250         list_del(&bundle->links);
 251
 252         put_device(&bundle->dev);
 253 }