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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  11
  12 #include <linux/kernel.h>
  13 #include <linux/slab.h>
  14
  15 #include "greybus.h"
  16
  17
  18 static struct ida gb_hd_bus_id_map;
  19
  20 int gb_hd_output(struct gb_host_device *hd, void *req, u16 size, u8 cmd,
  21                  bool async)
  22 {
  23         if (!hd || !hd->driver || !hd->driver->output)
  24                 return -EINVAL;
  25         return hd->driver->output(hd, req, size, cmd, async);
  26 }
  27 EXPORT_SYMBOL_GPL(gb_hd_output);
  28
  29 static void gb_hd_release(struct device *dev)
  30 {
  31         struct gb_host_device *hd = to_gb_host_device(dev);
  32
  33         if (hd->svc)
  34                 gb_svc_put(hd->svc);
  35         ida_simple_remove(&gb_hd_bus_id_map, hd->bus_id);
  36         ida_destroy(&hd->cport_id_map);
  37         kfree(hd);
  38 }
  39
  40 struct device_type greybus_hd_type = {
  41         .name           = "greybus_host_device",
  42         .release        = gb_hd_release,
  43 };
  44
  45 struct gb_host_device *gb_hd_create(struct gb_hd_driver *driver,
  46                                         struct device *parent,
  47                                         size_t buffer_size_max,
  48                                         size_t num_cports)
  49 {
  50         struct gb_host_device *hd;
  51         int ret;
  52
  53         /*
  54          * Validate that the driver implements all of the callbacks
  55          * so that we don't have to every time we make them.
  56          */
  57         if ((!driver->message_send) || (!driver->message_cancel)) {
  58                 pr_err("Must implement all gb_hd_driver callbacks!\n");
  59                 return ERR_PTR(-EINVAL);
  60         }
  61
  62         if (buffer_size_max < GB_OPERATION_MESSAGE_SIZE_MIN) {
  63                 dev_err(parent, "greybus host-device buffers too small\n");
  64                 return ERR_PTR(-EINVAL);
  65         }
  66
  67         if (num_cports == 0 || num_cports > CPORT_ID_MAX + 1) {
  68                 dev_err(parent, "Invalid number of CPorts: %zu\n", num_cports);
  69                 return ERR_PTR(-EINVAL);
  70         }
  71
  72         /*
  73          * Make sure to never allocate messages larger than what the Greybus
  74          * protocol supports.
  75          */
  76         if (buffer_size_max > GB_OPERATION_MESSAGE_SIZE_MAX) {
  77                 dev_warn(parent, "limiting buffer size to %u\n",
  78                          GB_OPERATION_MESSAGE_SIZE_MAX);
  79                 buffer_size_max = GB_OPERATION_MESSAGE_SIZE_MAX;
  80         }
  81
  82         hd = kzalloc(sizeof(*hd) + driver->hd_priv_size, GFP_KERNEL);
  83         if (!hd)
  84                 return ERR_PTR(-ENOMEM);
  85
  86         ret = ida_simple_get(&gb_hd_bus_id_map, 1, 0, GFP_KERNEL);
  87         if (ret < 0) {
  88                 kfree(hd);
  89                 return ERR_PTR(ret);
  90         }
  91         hd->bus_id = ret;
  92
  93         hd->driver = driver;
  94         INIT_LIST_HEAD(&hd->interfaces);
  95         INIT_LIST_HEAD(&hd->connections);
  96         ida_init(&hd->cport_id_map);
  97         hd->buffer_size_max = buffer_size_max;
  98         hd->num_cports = num_cports;
  99
 100         hd->dev.parent = parent;
 101         hd->dev.bus = &greybus_bus_type;
 102         hd->dev.type = &greybus_hd_type;
 103         hd->dev.dma_mask = hd->dev.parent->dma_mask;
 104         device_initialize(&hd->dev);
 105         dev_set_name(&hd->dev, "greybus%d", hd->bus_id);
 106
 107         hd->svc = gb_svc_create(hd);
 108         if (!hd->svc) {
 109                 dev_err(&hd->dev, "failed to create svc\n");
 110                 put_device(&hd->dev);
 111                 return ERR_PTR(-ENOMEM);
 112         }
 113
 114         return hd;
 115 }
 116 EXPORT_SYMBOL_GPL(gb_hd_create);
 117
 118 int gb_hd_add(struct gb_host_device *hd)
 119 {
 120         int ret;
 121
 122         ret = device_add(&hd->dev);
 123         if (ret)
 124                 return ret;
 125
 126         ret = gb_svc_add(hd->svc);
 127         if (ret) {
 128                 device_del(&hd->dev);
 129                 return ret;
 130         }
 131
 132         return 0;
 133 }
 134 EXPORT_SYMBOL_GPL(gb_hd_add);
 135
 136 void gb_hd_del(struct gb_host_device *hd)
 137 {
 138         gb_interfaces_remove(hd);
 139
 140         gb_svc_del(hd->svc);
 141
 142         device_del(&hd->dev);
 143 }
 144 EXPORT_SYMBOL_GPL(gb_hd_del);
 145
 146 void gb_hd_put(struct gb_host_device *hd)
 147 {
 148         put_device(&hd->dev);
 149 }
 150 EXPORT_SYMBOL_GPL(gb_hd_put);
 151
 152 int __init gb_hd_init(void)
 153 {
 154         ida_init(&gb_hd_bus_id_map);
 155
 156         return 0;
 157 }
 158
 159 void gb_hd_exit(void)
 160 {
 161         ida_destroy(&gb_hd_bus_id_map);
 162 }