drivers/staging/greybus/hd.c

   1 /*
   2  * Greybus Host Device
   3  *
   4  * Copyright 2014-2015 Google Inc.
   5  * Copyright 2014-2015 Linaro Ltd.
   6  *
   7  * Released under the GPLv2 only.
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/slab.h>
  12
  13 #include "greybus.h"
  14 #include "greybus_trace.h"
  15
  16 EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_create);
  17 EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_release);
  18 EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_add);
  19 EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_del);
  20 EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_in);
  21 EXPORT_TRACEPOINT_SYMBOL_GPL(gb_message_submit);
  22
  23 static struct ida gb_hd_bus_id_map;
  24
  25 int gb_hd_output(struct gb_host_device *hd, void *req, u16 size, u8 cmd,
  26                  bool async)
  27 {
  28         if (!hd || !hd->driver || !hd->driver->output)
  29                 return -EINVAL;
  30         return hd->driver->output(hd, req, size, cmd, async);
  31 }
  32 EXPORT_SYMBOL_GPL(gb_hd_output);
  33
  34 static ssize_t bus_id_show(struct device *dev,
  35                                 struct device_attribute *attr, char *buf)
  36 {
  37         struct gb_host_device *hd = to_gb_host_device(dev);
  38
  39         return sprintf(buf, "%d\n", hd->bus_id);
  40 }
  41 static DEVICE_ATTR_RO(bus_id);
  42
  43 static struct attribute *bus_attrs[] = {
  44         &dev_attr_bus_id.attr,
  45         NULL
  46 };
  47 ATTRIBUTE_GROUPS(bus);
  48
  49 int gb_hd_cport_reserve(struct gb_host_device *hd, u16 cport_id)
  50 {
  51         struct ida *id_map = &hd->cport_id_map;
  52         int ret;
  53
  54         ret = ida_simple_get(id_map, cport_id, cport_id + 1, GFP_KERNEL);
  55         if (ret < 0) {
  56                 dev_err(&hd->dev, "failed to reserve cport %u\n", cport_id);
  57                 return ret;
  58         }
  59
  60         return 0;
  61 }
  62 EXPORT_SYMBOL_GPL(gb_hd_cport_reserve);
  63
  64 void gb_hd_cport_release_reserved(struct gb_host_device *hd, u16 cport_id)
  65 {
  66         struct ida *id_map = &hd->cport_id_map;
  67
  68         ida_simple_remove(id_map, cport_id);
  69 }
  70 EXPORT_SYMBOL_GPL(gb_hd_cport_release_reserved);
  71
  72 /* Locking: Caller guarantees serialisation */
  73 int gb_hd_cport_allocate(struct gb_host_device *hd, int cport_id,
  74                                 unsigned long flags)
  75 {
  76         struct ida *id_map = &hd->cport_id_map;
  77         int ida_start, ida_end;
  78
  79         if (hd->driver->cport_allocate)
  80                 return hd->driver->cport_allocate(hd, cport_id, flags);
  81
  82         if (cport_id < 0) {
  83                 ida_start = 0;
  84                 ida_end = hd->num_cports;
  85         } else if (cport_id < hd->num_cports) {
  86                 ida_start = cport_id;
  87                 ida_end = cport_id + 1;
  88         } else {
  89                 dev_err(&hd->dev, "cport %d not available\n", cport_id);
  90                 return -EINVAL;
  91         }
  92
  93         return ida_simple_get(id_map, ida_start, ida_end, GFP_KERNEL);
  94 }
  95
  96 /* Locking: Caller guarantees serialisation */
  97 void gb_hd_cport_release(struct gb_host_device *hd, u16 cport_id)
  98 {
  99         if (hd->driver->cport_release) {
 100                 hd->driver->cport_release(hd, cport_id);
 101                 return;
 102         }
 103
 104         ida_simple_remove(&hd->cport_id_map, cport_id);
 105 }
 106
 107 static void gb_hd_release(struct device *dev)
 108 {
 109         struct gb_host_device *hd = to_gb_host_device(dev);
 110
 111         trace_gb_hd_release(hd);
 112
 113         if (hd->svc)
 114                 gb_svc_put(hd->svc);
 115         ida_simple_remove(&gb_hd_bus_id_map, hd->bus_id);
 116         ida_destroy(&hd->cport_id_map);
 117         kfree(hd);
 118 }
 119
 120 struct device_type greybus_hd_type = {
 121         .name           = "greybus_host_device",
 122         .release        = gb_hd_release,
 123 };
 124
 125 struct gb_host_device *gb_hd_create(struct gb_hd_driver *driver,
 126                                         struct device *parent,
 127                                         size_t buffer_size_max,
 128                                         size_t num_cports)
 129 {
 130         struct gb_host_device *hd;
 131         int ret;
 132
 133         /*
 134          * Validate that the driver implements all of the callbacks
 135          * so that we don't have to every time we make them.
 136          */
 137         if ((!driver->message_send) || (!driver->message_cancel)) {
 138                 dev_err(parent, "mandatory hd-callbacks missing\n");
 139                 return ERR_PTR(-EINVAL);
 140         }
 141
 142         if (buffer_size_max < GB_OPERATION_MESSAGE_SIZE_MIN) {
 143                 dev_err(parent, "greybus host-device buffers too small\n");
 144                 return ERR_PTR(-EINVAL);
 145         }
 146
 147         if (num_cports == 0 || num_cports > CPORT_ID_MAX + 1) {
 148                 dev_err(parent, "Invalid number of CPorts: %zu\n", num_cports);
 149                 return ERR_PTR(-EINVAL);
 150         }
 151
 152         /*
 153          * Make sure to never allocate messages larger than what the Greybus
 154          * protocol supports.
 155          */
 156         if (buffer_size_max > GB_OPERATION_MESSAGE_SIZE_MAX) {
 157                 dev_warn(parent, "limiting buffer size to %u\n",
 158                          GB_OPERATION_MESSAGE_SIZE_MAX);
 159                 buffer_size_max = GB_OPERATION_MESSAGE_SIZE_MAX;
 160         }
 161
 162         hd = kzalloc(sizeof(*hd) + driver->hd_priv_size, GFP_KERNEL);
 163         if (!hd)
 164                 return ERR_PTR(-ENOMEM);
 165
 166         ret = ida_simple_get(&gb_hd_bus_id_map, 1, 0, GFP_KERNEL);
 167         if (ret < 0) {
 168                 kfree(hd);
 169                 return ERR_PTR(ret);
 170         }
 171         hd->bus_id = ret;
 172
 173         hd->driver = driver;
 174         INIT_LIST_HEAD(&hd->modules);
 175         INIT_LIST_HEAD(&hd->connections);
 176         ida_init(&hd->cport_id_map);
 177         hd->buffer_size_max = buffer_size_max;
 178         hd->num_cports = num_cports;
 179
 180         hd->dev.parent = parent;
 181         hd->dev.bus = &greybus_bus_type;
 182         hd->dev.type = &greybus_hd_type;
 183         hd->dev.groups = bus_groups;
 184         hd->dev.dma_mask = hd->dev.parent->dma_mask;
 185         device_initialize(&hd->dev);
 186         dev_set_name(&hd->dev, "greybus%d", hd->bus_id);
 187
 188         trace_gb_hd_create(hd);
 189
 190         hd->svc = gb_svc_create(hd);
 191         if (!hd->svc) {
 192                 dev_err(&hd->dev, "failed to create svc\n");
 193                 put_device(&hd->dev);
 194                 return ERR_PTR(-ENOMEM);
 195         }
 196
 197         return hd;
 198 }
 199 EXPORT_SYMBOL_GPL(gb_hd_create);
 200
 201 int gb_hd_add(struct gb_host_device *hd)
 202 {
 203         int ret;
 204
 205         ret = device_add(&hd->dev);
 206         if (ret)
 207                 return ret;
 208
 209         ret = gb_svc_add(hd->svc);
 210         if (ret) {
 211                 device_del(&hd->dev);
 212                 return ret;
 213         }
 214
 215         trace_gb_hd_add(hd);
 216
 217         return 0;
 218 }
 219 EXPORT_SYMBOL_GPL(gb_hd_add);
 220
 221 void gb_hd_del(struct gb_host_device *hd)
 222 {
 223         trace_gb_hd_del(hd);
 224
 225         /*
 226          * Tear down the svc and flush any on-going hotplug processing before
 227          * removing the remaining interfaces.
 228          */
 229         gb_svc_del(hd->svc);
 230
 231         device_del(&hd->dev);
 232 }
 233 EXPORT_SYMBOL_GPL(gb_hd_del);
 234
 235 void gb_hd_shutdown(struct gb_host_device *hd)
 236 {
 237         gb_svc_del(hd->svc);
 238 }
 239 EXPORT_SYMBOL_GPL(gb_hd_shutdown);
 240
 241 void gb_hd_put(struct gb_host_device *hd)
 242 {
 243         put_device(&hd->dev);
 244 }
 245 EXPORT_SYMBOL_GPL(gb_hd_put);
 246
 247 int __init gb_hd_init(void)
 248 {
 249         ida_init(&gb_hd_bus_id_map);
 250
 251         return 0;
 252 }
 253
 254 void gb_hd_exit(void)
 255 {
 256         ida_destroy(&gb_hd_bus_id_map);
 257 }