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         snprintf(host->class_dev.bus_id, BUS_ID_SIZE,
  77                  "mmc%d", host->index);
  78
  79         host->parent = dev;
  80         host->class_dev.parent = dev;
  81         host->class_dev.class = &mmc_host_class;
  82         device_initialize(&host->class_dev);
  83
  84         spin_lock_init(&host->lock);
  85         init_waitqueue_head(&host->wq);
  86         INIT_DELAYED_WORK(&host->detect, mmc_rescan);
  87
  88         /*
  89          * By default, hosts do not support SGIO or large requests.
  90          * They have to set these according to their abilities.
  91          */
  92         host->max_hw_segs = 1;
  93         host->max_phys_segs = 1;
  94         host->max_seg_size = PAGE_CACHE_SIZE;
  95
  96         host->max_req_size = PAGE_CACHE_SIZE;
  97         host->max_blk_size = 512;
  98         host->max_blk_count = PAGE_CACHE_SIZE / 512;
  99
 100         return host;
 101
 102 free:
 103         kfree(host);
 104         return NULL;
 105 }
 106
 107 EXPORT_SYMBOL(mmc_alloc_host);
 108
 109 /**
 110  *      mmc_add_host - initialise host hardware
 111  *      @host: mmc host
 112  *
 113  *      Register the host with the driver model. The host must be
 114  *      prepared to start servicing requests before this function
 115  *      completes.
 116  */
 117 int mmc_add_host(struct mmc_host *host)
 118 {
 119         int err;
 120
 121         WARN_ON((host->caps & MMC_CAP_SDIO_IRQ) &&
 122                 !host->ops->enable_sdio_irq);
 123
 124         led_trigger_register_simple(host->class_dev.bus_id, &host->led);
 125
 126         err = device_add(&host->class_dev);
 127         if (err)
 128                 return err;
 129
 130         mmc_start_host(host);
 131
 132         return 0;
 133 }
 134
 135 EXPORT_SYMBOL(mmc_add_host);
 136
 137 /**
 138  *      mmc_remove_host - remove host hardware
 139  *      @host: mmc host
 140  *
 141  *      Unregister and remove all cards associated with this host,
 142  *      and power down the MMC bus. No new requests will be issued
 143  *      after this function has returned.
 144  */
 145 void mmc_remove_host(struct mmc_host *host)
 146 {
 147         mmc_stop_host(host);
 148
 149         device_del(&host->class_dev);
 150
 151         led_trigger_unregister_simple(host->led);
 152 }
 153
 154 EXPORT_SYMBOL(mmc_remove_host);
 155
 156 /**
 157  *      mmc_free_host - free the host structure
 158  *      @host: mmc host
 159  *
 160  *      Free the host once all references to it have been dropped.
 161  */
 162 void mmc_free_host(struct mmc_host *host)
 163 {
 164         spin_lock(&mmc_host_lock);
 165         idr_remove(&mmc_host_idr, host->index);
 166         spin_unlock(&mmc_host_lock);
 167
 168         put_device(&host->class_dev);
 169 }
 170
 171 EXPORT_SYMBOL(mmc_free_host);
 172