u-boot/doc/README.atmel_mci
Masahiro Yamada 54925327fa mmc: move CONFIG_GENERIC_MMC to Kconfig
Now, CONFIG_GENERIC_MMC seems equivalent to CONFIG_MMC.

Let's create an entry for "config GENERIC_MMC" with "default MMC",
then convert all macro defines in headers to Kconfig.  Almost all
of the defines will go away.

I see only two exceptions:
  configs/blanche_defconfig
  configs/sandbox_noblk_defconfig

They define CONFIG_GENERIC_MMC, but not CONFIG_MMC.  Something
might be wrong with these two boards, so should be checked later.

Anyway, this is the output of the moveconfig tool.

This commit was created as follows:

[1] create a config entry in drivers/mmc/Kconfig

[2] tools/moveconfig.py -r HEAD GENERIC_MMC

[3] manual clean-up of garbage comments in doc/README.* and
    include/configs/*.h

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
2017-01-31 21:50:47 +09:00

76 lines
2.3 KiB
Plaintext

How to use SD/MMC cards with Atmel SoCs having MCI hardware
-----------------------------------------------------------
2010-08-16 Reinhard Meyer <reinhard.meyer@emk-elektronik.de>
This is a new approach to use Atmel MCI hardware with the
general MMC framework. Therefore it benefits from that
framework's abilities to handle SDHC Cards and the ability
to write blocks.
- AT91SAM9XE512 (tested, will definitely work with XE128 and XE256)
- AT91SAM9260 (not tested, but MCI is to AT91SAM9XE)
- AT91SAM9G20 (not tested, should work)
It should work with all other ATMEL devices that have MCI,
including AVR32.
The generic driver does NOT assign port pins to the MCI block
nor does it start the MCI clock. This has to be handled in a
board/SoC specific manner before the driver is initialized:
example: this is added to at91sam9260_devices.c:
#if defined(CONFIG_GENERIC_ATMEL_MCI)
void at91_mci_hw_init(void)
{
at91_set_a_periph(AT91_PIO_PORTA, 8, PUP); /* MCCK */
#if defined(CONFIG_ATMEL_MCI_PORTB)
at91_set_b_periph(AT91_PIO_PORTA, 1, PUP); /* MCCDB */
at91_set_b_periph(AT91_PIO_PORTA, 0, PUP); /* MCDB0 */
at91_set_b_periph(AT91_PIO_PORTA, 5, PUP); /* MCDB1 */
at91_set_b_periph(AT91_PIO_PORTA, 4, PUP); /* MCDB2 */
at91_set_b_periph(AT91_PIO_PORTA, 3, PUP); /* MCDB3 */
#else
at91_set_a_periph(AT91_PIO_PORTA, 7, PUP); /* MCCDA */
at91_set_a_periph(AT91_PIO_PORTA, 6, PUP); /* MCDA0 */
at91_set_a_periph(AT91_PIO_PORTA, 9, PUP); /* MCDA1 */
at91_set_a_periph(AT91_PIO_PORTA, 10, PUP); /* MCDA2 */
at91_set_a_periph(AT91_PIO_PORTA, 11, PUP); /* MCDA3 */
#endif
}
#endif
the board specific file need added:
...
#ifdef CONFIG_GENERIC_ATMEL_MCI
# include <mmc.h>
#endif
...
#ifdef CONFIG_GENERIC_ATMEL_MCI
/* this is a weak define that we are overriding */
int board_mmc_init(bd_t *bd)
{
/* Enable clock */
at91_sys_write(AT91_PMC_PCER, 1 << AT91SAM9260_ID_MCI);
at91_mci_hw_init();
/* This calls the atmel_mci_init in gen_atmel_mci.c */
return atmel_mci_init((void *)AT91_BASE_MCI);
}
/* this is a weak define that we are overriding */
int board_mmc_getcd(struct mmc *mmc)
{
return !at91_get_gpio_value(CONFIG_SYS_MMC_CD_PIN);
}
#endif
and the board definition files needs:
/* SD/MMC card */
#define CONFIG_GENERIC_ATMEL_MCI 1
#define CONFIG_ATMEL_MCI_PORTB 1 /* Atmel XE-EK uses port B */
#define CONFIG_SYS_MMC_CD_PIN AT91_PIN_PC9
#define CONFIG_CMD_MMC 1