drivers/greybus/hd.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Greybus Host Device
   4  *
   5  * Copyright 2014-2015 Google Inc.
   6  * Copyright 2014-2015 Linaro Ltd.
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/slab.h>
  11 #include <linux/greybus.h>
  12
  13 #include "greybus_trace.h"
  14
  15 EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_create);
  16 EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_release);
  17 EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_add);
  18 EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_del);
  19 EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_in);
  20 EXPORT_TRACEPOINT_SYMBOL_GPL(gb_message_submit);
  21
  22 static struct ida gb_hd_bus_id_map;
  23
  24 int gb_hd_output(struct gb_host_device *hd, void *req, u16 size, u8 cmd,
  25                  bool async)
  26 {
  27         if (!hd || !hd->driver || !hd->driver->output)
  28                 return -EINVAL;
  29         return hd->driver->output(hd, req, size, cmd, async);
  30 }
  31 EXPORT_SYMBOL_GPL(gb_hd_output);
  32
  33 static ssize_t bus_id_show(struct device *dev,
  34                            struct device_attribute *attr, char *buf)
  35 {
  36         struct gb_host_device *hd = to_gb_host_device(dev);
  37
  38         return sprintf(buf, "%d\n", hd->bus_id);
  39 }
  40 static DEVICE_ATTR_RO(bus_id);
  41
  42 static struct attribute *bus_attrs[] = {
  43         &dev_attr_bus_id.attr,
  44         NULL
  45 };
  46 ATTRIBUTE_GROUPS(bus);
  47
  48 int gb_hd_cport_reserve(struct gb_host_device *hd, u16 cport_id)
  49 {
  50         struct ida *id_map = &hd->cport_id_map;
  51         int ret;
  52
  53         ret = ida_simple_get(id_map, cport_id, cport_id + 1, GFP_KERNEL);
  54         if (ret < 0) {
  55                 dev_err(&hd->dev, "failed to reserve cport %u\n", cport_id);
  56                 return ret;
  57         }
  58
  59         return 0;
  60 }
  61 EXPORT_SYMBOL_GPL(gb_hd_cport_reserve);
  62
  63 void gb_hd_cport_release_reserved(struct gb_host_device *hd, u16 cport_id)
  64 {
  65         struct ida *id_map = &hd->cport_id_map;
  66
  67         ida_simple_remove(id_map, cport_id);
  68 }
  69 EXPORT_SYMBOL_GPL(gb_hd_cport_release_reserved);
  70
  71 /* Locking: Caller guarantees serialisation */
  72 int gb_hd_cport_allocate(struct gb_host_device *hd, int cport_id,
  73                          unsigned long flags)
  74 {
  75         struct ida *id_map = &hd->cport_id_map;
  76         int ida_start, ida_end;
  77
  78         if (hd->driver->cport_allocate)
  79                 return hd->driver->cport_allocate(hd, cport_id, flags);
  80
  81         if (cport_id < 0) {
  82                 ida_start = 0;
  83                 ida_end = hd->num_cports;
  84         } else if (cport_id < hd->num_cports) {
  85                 ida_start = cport_id;
  86                 ida_end = cport_id + 1;
  87         } else {
  88                 dev_err(&hd->dev, "cport %d not available\n", cport_id);
  89                 return -EINVAL;
  90         }
  91
  92         return ida_simple_get(id_map, ida_start, ida_end, GFP_KERNEL);
  93 }
  94
  95 /* Locking: Caller guarantees serialisation */
  96 void gb_hd_cport_release(struct gb_host_device *hd, u16 cport_id)
  97 {
  98         if (hd->driver->cport_release) {
  99                 hd->driver->cport_release(hd, cport_id);
 100                 return;
 101         }
 102
 103         ida_simple_remove(&hd->cport_id_map, cport_id);
 104 }
 105
 106 static void gb_hd_release(struct device *dev)
 107 {
 108         struct gb_host_device *hd = to_gb_host_device(dev);
 109
 110         trace_gb_hd_release(hd);
 111
 112         if (hd->svc)
 113                 gb_svc_put(hd->svc);
 114         ida_simple_remove(&gb_hd_bus_id_map, hd->bus_id);
 115         ida_destroy(&hd->cport_id_map);
 116         kfree(hd);
 117 }
 118
 119 struct device_type greybus_hd_type = {
 120         .name           = "greybus_host_device",
 121         .release        = gb_hd_release,
 122 };
 123
 124 struct gb_host_device *gb_hd_create(struct gb_hd_driver *driver,
 125                                     struct device *parent,
 126                                     size_t buffer_size_max,
 127                                     size_t num_cports)
 128 {
 129         struct gb_host_device *hd;
 130         int ret;
 131
 132         /*
 133          * Validate that the driver implements all of the callbacks
 134          * so that we don't have to every time we make them.
 135          */
 136         if ((!driver->message_send) || (!driver->message_cancel)) {
 137                 dev_err(parent, "mandatory hd-callbacks missing\n");
 138                 return ERR_PTR(-EINVAL);
 139         }
 140
 141         if (buffer_size_max < GB_OPERATION_MESSAGE_SIZE_MIN) {
 142                 dev_err(parent, "greybus host-device buffers too small\n");
 143                 return ERR_PTR(-EINVAL);
 144         }
 145
 146         if (num_cports == 0 || num_cports > CPORT_ID_MAX + 1) {
 147                 dev_err(parent, "Invalid number of CPorts: %zu\n", num_cports);
 148                 return ERR_PTR(-EINVAL);
 149         }
 150
 151         /*
 152          * Make sure to never allocate messages larger than what the Greybus
 153          * protocol supports.
 154          */
 155         if (buffer_size_max > GB_OPERATION_MESSAGE_SIZE_MAX) {
 156                 dev_warn(parent, "limiting buffer size to %u\n",
 157                          GB_OPERATION_MESSAGE_SIZE_MAX);
 158                 buffer_size_max = GB_OPERATION_MESSAGE_SIZE_MAX;
 159         }
 160
 161         hd = kzalloc(sizeof(*hd) + driver->hd_priv_size, GFP_KERNEL);
 162         if (!hd)
 163                 return ERR_PTR(-ENOMEM);
 164
 165         ret = ida_simple_get(&gb_hd_bus_id_map, 1, 0, GFP_KERNEL);
 166         if (ret < 0) {
 167                 kfree(hd);
 168                 return ERR_PTR(ret);
 169         }
 170         hd->bus_id = ret;
 171
 172         hd->driver = driver;
 173         INIT_LIST_HEAD(&hd->modules);
 174         INIT_LIST_HEAD(&hd->connections);
 175         ida_init(&hd->cport_id_map);
 176         hd->buffer_size_max = buffer_size_max;
 177         hd->num_cports = num_cports;
 178
 179         hd->dev.parent = parent;
 180         hd->dev.bus = &greybus_bus_type;
 181         hd->dev.type = &greybus_hd_type;
 182         hd->dev.groups = bus_groups;
 183         hd->dev.dma_mask = hd->dev.parent->dma_mask;
 184         device_initialize(&hd->dev);
 185         dev_set_name(&hd->dev, "greybus%d", hd->bus_id);
 186
 187         trace_gb_hd_create(hd);
 188
 189         hd->svc = gb_svc_create(hd);
 190         if (!hd->svc) {
 191                 dev_err(&hd->dev, "failed to create svc\n");
 192                 put_device(&hd->dev);
 193                 return ERR_PTR(-ENOMEM);
 194         }
 195
 196         return hd;
 197 }
 198 EXPORT_SYMBOL_GPL(gb_hd_create);
 199
 200 int gb_hd_add(struct gb_host_device *hd)
 201 {
 202         int ret;
 203
 204         ret = device_add(&hd->dev);
 205         if (ret)
 206                 return ret;
 207
 208         ret = gb_svc_add(hd->svc);
 209         if (ret) {
 210                 device_del(&hd->dev);
 211                 return ret;
 212         }
 213
 214         trace_gb_hd_add(hd);
 215
 216         return 0;
 217 }
 218 EXPORT_SYMBOL_GPL(gb_hd_add);
 219
 220 void gb_hd_del(struct gb_host_device *hd)
 221 {
 222         trace_gb_hd_del(hd);
 223
 224         /*
 225          * Tear down the svc and flush any on-going hotplug processing before
 226          * removing the remaining interfaces.
 227          */
 228         gb_svc_del(hd->svc);
 229
 230         device_del(&hd->dev);
 231 }
 232 EXPORT_SYMBOL_GPL(gb_hd_del);
 233
 234 void gb_hd_shutdown(struct gb_host_device *hd)
 235 {
 236         gb_svc_del(hd->svc);
 237 }
 238 EXPORT_SYMBOL_GPL(gb_hd_shutdown);
 239
 240 void gb_hd_put(struct gb_host_device *hd)
 241 {
 242         put_device(&hd->dev);
 243 }
 244 EXPORT_SYMBOL_GPL(gb_hd_put);
 245
 246 int __init gb_hd_init(void)
 247 {
 248         ida_init(&gb_hd_bus_id_map);
 249
 250         return 0;
 251 }
 252
 253 void gb_hd_exit(void)
 254 {
 255         ida_destroy(&gb_hd_bus_id_map);
 256 }