sd.c

#include <rtthread.h>
#include <dfs_fs.h>
#include <lpc214x.h>

#include "sd.h"

static struct rt_device sd;
static struct dfs_partition part;

static rt_err_t rt_sdcard_init(rt_device_t dev)
{
    return RT_EOK;
}

static rt_err_t rt_sdcard_open(rt_device_t dev, rt_uint16_t oflag)
{
	return RT_EOK;
}

static rt_err_t rt_sdcard_close(rt_device_t dev)
{
	return RT_EOK;
}

static rt_size_t rt_sdcard_read(rt_device_t dev, rt_off_t pos, void* buffer, rt_size_t size)
{
    /* append partition offset */
    pos += part.offset * 512;

    return 0;
}

static rt_size_t rt_sdcard_write (rt_device_t dev, rt_off_t pos, const void* buffer, rt_size_t size)
{
    /* append partition offset */
    pos += part.offset * 512;

    return 0;
}

static rt_err_t rt_sdcard_control(rt_device_t dev, rt_uint8_t cmd, void *args)
{
	return RT_EOK;
}

void rt_hw_sdcard_init()
{
    rt_size_t length;
	rt_uint8_t* sector;

    /* sdcard hardware init */

	sd.type     = RT_Device_Class_Block;
	sd.init 	= rt_sdcard_init;
	sd.open 	= rt_sdcard_open;
	sd.close    = rt_sdcard_close;
	sd.read 	= rt_sdcard_read;
	sd.write    = rt_sdcard_write;
	sd.control  = rt_sdcard_control;
	sd.user_data  = RT_NULL;

	/* get the first sector to read partition table */
	sector = (rt_uint8_t*) rt_malloc (512);
	if (sector == RT_NULL)
	{
		rt_kprintf("allocate partition sector buffer failed\n");
		return;
	}

	length = rt_sdcard_read((rt_device_t)&sd, 0, sector, 512);
	if (length == 512)
	{
		rt_err_t status;

		/* get the first partition */
		status = dfs_filesystem_get_partition(&part, sector, 0);
		if (status != RT_EOK)
		{
			/* there is no partition table */
			part.offset = 0;
			part.size   = 0;
		}
	}
	else
	{
		/* there is no partition table */
		part.offset = 0;
		part.size   = 0;
	}

	rt_device_register(&sd,
		"sd", RT_DEVICE_FLAG_RDWR);
}