projects / people / ms / u-boot.git / blame
| Commit | Line | Data |
|---|---|---|
| 1592ef85 RM |
1 | How to use SD/MMC cards with Atmel SoCs having MCI hardware |
| 2 | ----------------------------------------------------------- | |
| 3 | 2010-08-16 Reinhard Meyer <reinhard.meyer@emk-elektronik.de> | |
| 4 | ||
| 5 | This is a new approach to use Atmel MCI hardware with the | |
| 6 | general MMC framework. Therefore it benefits from that | |
| 7 | framework's abilities to handle SDHC Cards and the ability | |
| 8 | to write blocks. | |
| 9 | ||
| 10 | - AT91SAM9XE512 (tested, will definitely work with XE128 and XE256) | |
| 11 | - AT91SAM9260 (not tested, but MCI is to AT91SAM9XE) | |
| 12 | - AT91SAM9G20 (not tested, should work) | |
| 13 | ||
| daab59ac | 14 | It should work with all other ATMEL devices that have MCI. |
| 1592ef85 RM |
15 | |
| 16 | The generic driver does NOT assign port pins to the MCI block | |
| 17 | nor does it start the MCI clock. This has to be handled in a | |
| 18 | board/SoC specific manner before the driver is initialized: | |
| 19 | ||
| 20 | example: this is added to at91sam9260_devices.c: | |
| 21 | ||
| c9abb426 | 22 | #if defined(CONFIG_GENERIC_ATMEL_MCI) |
| 1592ef85 RM |
23 | void at91_mci_hw_init(void) |
| 24 | { | |
| 25 | at91_set_a_periph(AT91_PIO_PORTA, 8, PUP); /* MCCK */ | |
| 26 | #if defined(CONFIG_ATMEL_MCI_PORTB) | |
| 27 | at91_set_b_periph(AT91_PIO_PORTA, 1, PUP); /* MCCDB */ | |
| 28 | at91_set_b_periph(AT91_PIO_PORTA, 0, PUP); /* MCDB0 */ | |
| 29 | at91_set_b_periph(AT91_PIO_PORTA, 5, PUP); /* MCDB1 */ | |
| 30 | at91_set_b_periph(AT91_PIO_PORTA, 4, PUP); /* MCDB2 */ | |
| 31 | at91_set_b_periph(AT91_PIO_PORTA, 3, PUP); /* MCDB3 */ | |
| 32 | #else | |
| 33 | at91_set_a_periph(AT91_PIO_PORTA, 7, PUP); /* MCCDA */ | |
| 34 | at91_set_a_periph(AT91_PIO_PORTA, 6, PUP); /* MCDA0 */ | |
| 35 | at91_set_a_periph(AT91_PIO_PORTA, 9, PUP); /* MCDA1 */ | |
| 36 | at91_set_a_periph(AT91_PIO_PORTA, 10, PUP); /* MCDA2 */ | |
| 37 | at91_set_a_periph(AT91_PIO_PORTA, 11, PUP); /* MCDA3 */ | |
| 38 | #endif | |
| 39 | } | |
| 40 | #endif | |
| 41 | ||
| 42 | the board specific file need added: | |
| 43 | ... | |
| 44 | #ifdef CONFIG_GENERIC_ATMEL_MCI | |
| 45 | # include <mmc.h> | |
| 46 | #endif | |
| 47 | ... | |
| 48 | #ifdef CONFIG_GENERIC_ATMEL_MCI | |
| 49 | /* this is a weak define that we are overriding */ | |
| 50 | int board_mmc_init(bd_t *bd) | |
| 51 | { | |
| 52 | /* Enable clock */ | |
| 53 | at91_sys_write(AT91_PMC_PCER, 1 << AT91SAM9260_ID_MCI); | |
| 54 | at91_mci_hw_init(); | |
| 55 | ||
| 56 | /* This calls the atmel_mci_init in gen_atmel_mci.c */ | |
| 57 | return atmel_mci_init((void *)AT91_BASE_MCI); | |
| 58 | } | |
| 59 | ||
| 60 | /* this is a weak define that we are overriding */ | |
| 314284b1 | 61 | int board_mmc_getcd(struct mmc *mmc) |
| 1592ef85 | 62 | { |
| 314284b1 | 63 | return !at91_get_gpio_value(CONFIG_SYS_MMC_CD_PIN); |
| 1592ef85 RM |
64 | } |
| 65 | ||
| 66 | #endif | |
| 67 | ||
| 68 | and the board definition files needs: | |
| 69 | ||
| 70 | /* SD/MMC card */ | |
| 1592ef85 RM |
71 | #define CONFIG_GENERIC_ATMEL_MCI 1 |
| 72 | #define CONFIG_ATMEL_MCI_PORTB 1 /* Atmel XE-EK uses port B */ | |
| 73 | #define CONFIG_SYS_MMC_CD_PIN AT91_PIN_PC9 | |
| 74 | #define CONFIG_CMD_MMC 1 |