基于QualComm的mmc driver解析（Kernel-3.10）——（2）sdio总线

sdio总线的注册函数也是在core.c 文件中调用注册的：

ret = sdio_register_bus();
if (ret)
goto unregister_host_class;

sdio_register_bus

在sdio_bus.c 文件中定义：

int sdio_register_bus(void)
{
return bus_register(&sdio_bus_type);
}

sdio_register_bus

通过

bus_register

函数注册了sdio总线， sdio总线的结构体定义如下：

static struct bus_type sdio_bus_type = {
.name       = "sdio",
.dev_attrs  = sdio_dev_attrs,
.match      = sdio_bus_match,
.uevent     = sdio_bus_uevent,
.probe      = sdio_bus_probe,
.remove     = sdio_bus_remove,
.pm     = SDIO_PM_OPS_PTR,
};

总线名字为sdio，

sdio_dev_attrs

在bus目录下创建属性节点。

sdio_bus_match

函数定义：

static int sdio_bus_match(struct device *dev, struct device_driver *drv)
{
struct sdio_func *func = dev_to_sdio_func(dev);
struct sdio_driver *sdrv = to_sdio_driver(drv);

if (sdio_match_device(func, sdrv))
return 1;

return 0;
}

调用

sdio_match_device

:

static const struct sdio_device_id *sdio_match_device(struct sdio_func *func,
struct sdio_driver *sdrv)
{
const struct sdio_device_id *ids;

ids = sdrv->id_table;

if (ids) {
while (ids->class || ids->vendor || ids->device) {
if (sdio_match_one(func, ids))
return ids;
ids++;
}
}

return NULL;
}

以上两个函数是driver 匹配device使用的函数。

sdio_bus_probe

函数：

static int sdio_bus_probe(struct device *dev)
{
struct sdio_driver *drv = to_sdio_driver(dev->driver);
struct sdio_func *func = dev_to_sdio_func(dev);
const struct sdio_device_id *id;
int ret;

id = sdio_match_device(func, drv);
if (!id)
return -ENODEV;

/* Unbound SDIO functions are always suspended.
* During probe, the function is set active and the usage count
* is incremented.  If the driver supports runtime PM,
* it should call pm_runtime_put_noidle() in its probe routine and
* pm_runtime_get_noresume() in its remove routine.
*/
if (func->card->host->caps & MMC_CAP_POWER_OFF_CARD) {
ret = pm_runtime_get_sync(dev);
if (ret < 0)
goto disable_runtimepm;
}

/* Set the default block size so the driver is sure it's something
* sensible. */
sdio_claim_host(func);
ret = sdio_set_block_size(func, 0);
sdio_release_host(func);
if (ret)
goto disable_runtimepm;

ret = drv->probe(func, id);
if (ret)
goto disable_runtimepm;

return 0;

disable_runtimepm:
if (func->card->host->caps & MMC_CAP_POWER_OFF_CARD)
pm_runtime_put_noidle(dev);
return ret;
}