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Code

tornado/fw/mmc-hw.c: complete hardware driver (untested)

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This commit is contained in:
Werner Almesberger 2012-12-04 11:56:56 -03:00
parent a1c7a948d2
commit 4064698884
1 changed files with 64 additions and 9 deletions
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73
tornado/fw/mmc-hw.c
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@ -13,43 +13,98 @@
#include <stdint.h>
#define F_CPU 8000000UL
#include <util/delay.h>
#include "io.h"
#include "mmc-hw.h"
/*
* Pin assignment from
* http://alumni.cs.ucr.edu/~amitra/sdcard/ProdManualSDCardv1.9.pdf
*
* Pin SD mode SPI mode
* 1 DAT3 Chip Select (active low)
* 2 CMD MOSI
* 3 VSS VSS
* 4 VDD VDD
* 5 CLK Clock
* 6 VSS VSS
* 7 DAT0 MISO
*/
#define MMC_nCS CARD_DAT3
#define MMC_MOSI CARD_CMD
#define MMC_CLK CARD_CLK
#define MMC_MISO CARD_DAT0
void mmc_select(void)
{
// CS = 0;
CLR(MMC_nCS);
}
void mmc_deselect(void)
{
// CS = 1;
SET(MMC_nCS);
}
uint8_t mmc_recv(void)
{
// MSB first
return 0;
uint8_t i, v = 0;
for (i = 0; i != 8; i++) {
SET(MMC_CLK);
v = (v << 1) | PIN(MMC_MISO);
CLR(MMC_CLK);
}
return v;
}
void mmc_send(uint8_t v)
{
// MSB first
uint8_t i;
for (i = 0; i != 8; i++) {
if (v & 0x80)
SET(MMC_MOSI);
else
CLR(MMC_MOSI);
SET(MMC_CLK);
CLR(MMC_CLK);
v <<= 1;
}
}
void mmc_activate(void)
{
// set pull-ups
// VDD = 1;
SET(MMC_nCS);
CLR(MMC_CLK);
OUT(MMC_nCS);
OUT(MMC_MOSI);
OUT(MMC_CLK);
IN(MMC_MISO);
CLR(CARD_nPWR);
_delay_ms(10);
}
void mmc_deactivate(void)
{
// set directions
// VDD = 0;
CLR(MMC_CLK);
CLR(MMC_nCS);
CLR(MMC_MOSI);
CLR(MMC_MISO);
SET(CARD_nPWR);
_delay_ms(10);
OUT(MMC_MISO);
}