1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
|
/*-----------------------------------------------------------------------*/
/* Low level disk I/O module skeleton for Petit FatFs (C)ChaN, 2014 */
/*-----------------------------------------------------------------------*/
#include "diskio.h"
#include "sd.h"
#include "spi.h"
#include "util.h"
static void spi_rx_multi(BYTE *buff, UINT cnt) {
do {
*buff++ = spi_rx();
} while (--cnt);
}
static int rcv_datablock(BYTE *buff, UINT btr) {
uint8_t token;
uint16_t count = 10000;
do token = spi_rx(); while (token == 0xff && --count);
if (token != 0xfe)
return 0;
spi_rx_multi(buff, btr);
spi_rx();
spi_rx();
return 1;
}
/*-----------------------------------------------------------------------*/
/* Initialize Disk Drive */
/*-----------------------------------------------------------------------*/
static DSTATUS status = STA_NODISK;
DSTATUS disk_status(BYTE pdrv) {
if (pdrv)
return STA_NOINIT;
return status;
}
DSTATUS disk_initialize (BYTE pdrv)
{
uint8_t n, cmd;
uint32_t tmr;
if (!status)
return 0;
#ifdef DEBUG
printf("Init SD\r\n");
#endif
if (sd_init())
return STA_NOINIT;
#ifdef DEBUG
printf("Done disk_initialize\r\n");
#endif
status = 0;
return 0;
}
/*-----------------------------------------------------------------------*/
/* Read Partial Sector */
/*-----------------------------------------------------------------------*/
DRESULT disk_read (
BYTE pdrv, /* Physical drive number (0) */
BYTE* buff, /* Pointer to the destination object */
DWORD sector, /* Sector number (LBA) */
UINT count /* Byte count (bit15:destination) */
)
{
DRESULT res = RES_ERROR;
BYTE rc;
UINT bc;
if (pdrv || !count)
return RES_PARERR;
if (status && STA_NOINIT)
return RES_NOTRDY;
sector *= 512;
if (count == 1) {
if ((sd_send_command(SD_READ_SINGLE_BLOCK, sector) == 0)
&& rcv_datablock(buff, 512))
count = 0;
} else if (sd_send_command(SD_READ_MULTIPLE_BLOCK, sector) == 0) {
do {
if (!rcv_datablock(buff, 512))
break;
buff += 512;
} while (--count);
sd_send_command(SD_STOP_TRANSMISSION, 0);
}
SD_DESELECT();
spi_rx();
return count ? RES_ERROR : RES_OK;
}
|
