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