drivers/mmc/core/host.c

   1 /*
   2  *  linux/drivers/mmc/core/host.c
   3  *
   4  *  Copyright (C) 2003 Russell King, All Rights Reserved.
   5  *  Copyright (C) 2007-2008 Pierre Ossman
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  *  MMC host class device management
  12  */
  13
  14 #include <linux/device.h>
  15 #include <linux/err.h>
  16 #include <linux/idr.h>
  17 #include <linux/pagemap.h>
  18 #include <linux/leds.h>
  19 #include <linux/slab.h>
  20 #include <linux/suspend.h>
  21
  22 #include <linux/mmc/host.h>
  23
  24 #include "core.h"
  25 #include "host.h"
  26
  27 #define cls_dev_to_mmc_host(d)  container_of(d, struct mmc_host, class_dev)
  28
  29 static void mmc_host_classdev_release(struct device *dev)
  30 {
  31         struct mmc_host *host = cls_dev_to_mmc_host(dev);
  32         kfree(host);
  33 }
  34
  35 static struct class mmc_host_class = {
  36         .name           = "mmc_host",
  37         .dev_release    = mmc_host_classdev_release,
  38 };
  39
  40 int mmc_register_host_class(void)
  41 {
  42         return class_register(&mmc_host_class);
  43 }
  44
  45 void mmc_unregister_host_class(void)
  46 {
  47         class_unregister(&mmc_host_class);
  48 }
  49
  50 static DEFINE_IDR(mmc_host_idr);
  51 static DEFINE_SPINLOCK(mmc_host_lock);
  52
  53 /**
  54  *      mmc_alloc_host - initialise the per-host structure.
  55  *      @extra: sizeof private data structure
  56  *      @dev: pointer to host device model structure
  57  *
  58  *      Initialise the per-host structure.
  59  */
  60 struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
  61 {
  62         int err;
  63         struct mmc_host *host;
  64
  65         if (!idr_pre_get(&mmc_host_idr, GFP_KERNEL))
  66                 return NULL;
  67
  68         host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
  69         if (!host)
  70                 return NULL;
  71
  72         spin_lock(&mmc_host_lock);
  73         err = idr_get_new(&mmc_host_idr, host, &host->index);
  74         spin_unlock(&mmc_host_lock);
  75         if (err)
  76                 goto free;
  77
  78         dev_set_name(&host->class_dev, "mmc%d", host->index);
  79
  80         host->parent = dev;
  81         host->class_dev.parent = dev;
  82         host->class_dev.class = &mmc_host_class;
  83         device_initialize(&host->class_dev);
  84
  85         spin_lock_init(&host->lock);
  86         init_waitqueue_head(&host->wq);
  87         INIT_DELAYED_WORK(&host->detect, mmc_rescan);
  88         INIT_DELAYED_WORK_DEFERRABLE(&host->disable, mmc_host_deeper_disable);
  89 #ifdef CONFIG_PM
  90         host->pm_notify.notifier_call = mmc_pm_notify;
  91 #endif
  92
  93         /*
  94          * By default, hosts do not support SGIO or large requests.
  95          * They have to set these according to their abilities.
  96          */
  97         host->max_segs = 1;
  98         host->max_seg_size = PAGE_CACHE_SIZE;
  99
 100         host->max_req_size = PAGE_CACHE_SIZE;
 101         host->max_blk_size = 512;
 102         host->max_blk_count = PAGE_CACHE_SIZE / 512;
 103
 104         return host;
 105
 106 free:
 107         kfree(host);
 108         return NULL;
 109 }
 110
 111 EXPORT_SYMBOL(mmc_alloc_host);
 112
 113 /**
 114  *      mmc_add_host - initialise host hardware
 115  *      @host: mmc host
 116  *
 117  *      Register the host with the driver model. The host must be
 118  *      prepared to start servicing requests before this function
 119  *      completes.
 120  */
 121 int mmc_add_host(struct mmc_host *host)
 122 {
 123         int err;
 124
 125         WARN_ON((host->caps & MMC_CAP_SDIO_IRQ) &&
 126                 !host->ops->enable_sdio_irq);
 127
 128         led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
 129
 130         err = device_add(&host->class_dev);
 131         if (err)
 132                 return err;
 133
 134 #ifdef CONFIG_DEBUG_FS
 135         mmc_add_host_debugfs(host);
 136 #endif
 137
 138         mmc_start_host(host);
 139         register_pm_notifier(&host->pm_notify);
 140
 141         return 0;
 142 }
 143
 144 EXPORT_SYMBOL(mmc_add_host);
 145
 146 /**
 147  *      mmc_remove_host - remove host hardware
 148  *      @host: mmc host
 149  *
 150  *      Unregister and remove all cards associated with this host,
 151  *      and power down the MMC bus. No new requests will be issued
 152  *      after this function has returned.
 153  */
 154 void mmc_remove_host(struct mmc_host *host)
 155 {
 156         unregister_pm_notifier(&host->pm_notify);
 157         mmc_stop_host(host);
 158
 159 #ifdef CONFIG_DEBUG_FS
 160         mmc_remove_host_debugfs(host);
 161 #endif
 162
 163         device_del(&host->class_dev);
 164
 165         led_trigger_unregister_simple(host->led);
 166 }
 167
 168 EXPORT_SYMBOL(mmc_remove_host);
 169
 170 /**
 171  *      mmc_free_host - free the host structure
 172  *      @host: mmc host
 173  *
 174  *      Free the host once all references to it have been dropped.
 175  */
 176 void mmc_free_host(struct mmc_host *host)
 177 {
 178         spin_lock(&mmc_host_lock);
 179         idr_remove(&mmc_host_idr, host->index);
 180         spin_unlock(&mmc_host_lock);
 181
 182         put_device(&host->class_dev);
 183 }
 184
 185 EXPORT_SYMBOL(mmc_free_host);
 186