esp-idf/components/sdmmc/sdmmc_init.c

/*
 * Copyright (c) 2006 Uwe Stuehler <uwe@openbsd.org>
 * Adaptations to ESP-IDF Copyright (c) 2016-2018 Espressif Systems (Shanghai) PTE LTD
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "sdmmc_common.h"

static const char* TAG = "sdmmc_init";

#define SDMMC_INIT_STEP(condition, function) \
    do { \
        if ((condition)) { \
            esp_err_t err = (function)(card); \
            if (err != ESP_OK) { \
                ESP_LOGD(TAG, "%s: %s returned 0x%x", __func__, #function, err); \
                return err; \
            } \
        } \
    } while(0);


esp_err_t sdmmc_card_init(const sdmmc_host_t* config, sdmmc_card_t* card)
{
    memset(card, 0, sizeof(*card));
    memcpy(&card->host, config, sizeof(*config));
    const bool is_spi = host_is_spi(card);
    const bool always = true;
    const bool io_supported = true;

    /* Check if host flags are compatible with slot configuration. */
    SDMMC_INIT_STEP(!is_spi, sdmmc_fix_host_flags);

    /* Reset SDIO (CMD52, RES) before re-initializing IO (CMD5). */
    SDMMC_INIT_STEP(io_supported, sdmmc_io_reset);

    /* GO_IDLE_STATE (CMD0) command resets the card */
    SDMMC_INIT_STEP(always, sdmmc_send_cmd_go_idle_state);

    /* SEND_IF_COND (CMD8) command is used to identify SDHC/SDXC cards. */
    SDMMC_INIT_STEP(always, sdmmc_init_sd_if_cond);

    /* IO_SEND_OP_COND(CMD5), Determine if the card is an IO card. */
    SDMMC_INIT_STEP(io_supported, sdmmc_init_io);

    const bool is_mem = card->is_mem;
    const bool is_sdio = !is_mem;

    /* Enable CRC16 checks for data transfers in SPI mode */
    SDMMC_INIT_STEP(is_spi, sdmmc_init_spi_crc);

    /* Use SEND_OP_COND to set up card OCR */
    SDMMC_INIT_STEP(is_mem, sdmmc_init_ocr);

    const bool is_mmc = is_mem && card->is_mmc;
    const bool is_sdmem = is_mem && !is_mmc;

    ESP_LOGD(TAG, "%s: card type is %s", __func__,
            is_sdio ? "SDIO" : is_mmc ? "MMC" : "SD");

    /* Read and decode the contents of CID register and assign RCA */
    SDMMC_INIT_STEP(always, sdmmc_init_cid);

    /* Read and decode the contents of CSD register */
    SDMMC_INIT_STEP(is_mem, sdmmc_init_csd);

    /* Switch the card from stand-by mode to data transfer mode (not needed if
     * SPI interface is used). This is needed to issue SET_BLOCKLEN and
     * SEND_SCR commands.
     */
    SDMMC_INIT_STEP(!is_spi, sdmmc_init_select_card);

    /* SD memory cards:
     * Set block len for SDSC cards to 512 bytes (same as SDHC)
     * Read SCR
     * Wait to enter data transfer state
     */
    SDMMC_INIT_STEP(is_sdmem, sdmmc_init_sd_blocklen);
    SDMMC_INIT_STEP(is_sdmem, sdmmc_init_sd_scr);
    SDMMC_INIT_STEP(is_sdmem, sdmmc_init_sd_wait_data_ready);

    /* MMC cards: read CXD */
    SDMMC_INIT_STEP(is_mmc, sdmmc_init_mmc_read_ext_csd);

    /* Try to switch card to HS mode if the card supports it.
     * Set card->max_freq_khz value accordingly.
     */
    SDMMC_INIT_STEP(always, sdmmc_init_card_hs_mode);

    /* Set bus width. One call for every kind of card, then one for the host */
    if (!is_spi) {
        SDMMC_INIT_STEP(is_sdmem, sdmmc_init_sd_bus_width);
        SDMMC_INIT_STEP(is_sdio, sdmmc_init_io_bus_width);
        SDMMC_INIT_STEP(is_mmc, sdmmc_init_mmc_bus_width);
        SDMMC_INIT_STEP(always, sdmmc_init_host_bus_width);
    }

    /* Switch to the host to use card->max_freq_khz frequency. */
    SDMMC_INIT_STEP(always, sdmmc_init_host_frequency);

    /* Sanity check after switching the bus mode and frequency */
    SDMMC_INIT_STEP(is_sdmem, sdmmc_check_scr);
    /* TODO: add similar checks for eMMC and SDIO */

    return ESP_OK;
}