diff options
Diffstat (limited to 'circuitpython/lib/sdmmc/sdmmc_init.c')
| -rw-r--r-- | circuitpython/lib/sdmmc/sdmmc_init.c | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/circuitpython/lib/sdmmc/sdmmc_init.c b/circuitpython/lib/sdmmc/sdmmc_init.c new file mode 100644 index 0000000..de5c739 --- /dev/null +++ b/circuitpython/lib/sdmmc/sdmmc_init.c @@ -0,0 +1,123 @@ +/* + * 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" + +#define SDMMC_INIT_STEP(condition, function) \ + do { \ + if ((condition)) { \ + sdmmc_err_t err = (function)(card); \ + if (err != SDMMC_OK) { \ + ESP_LOGD(TAG, "%s: %s returned 0x%x", __func__, #function, err); \ + return err; \ + } \ + } \ + } while(0); + + +sdmmc_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 the contents of CID register*/ + SDMMC_INIT_STEP(is_mem, sdmmc_init_cid); + + /* Assign RCA */ + SDMMC_INIT_STEP(!is_spi, sdmmc_init_rca); + + /* Read and decode the contents of CSD register */ + SDMMC_INIT_STEP(is_mem, sdmmc_init_csd); + + /* Decode the contents of mmc CID register */ + SDMMC_INIT_STEP(is_mmc && !is_spi, sdmmc_init_mmc_decode_cid); + + /* 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: this is CMD line only, add data checks for eMMC */ + SDMMC_INIT_STEP(is_mmc, sdmmc_init_mmc_check_csd); + /* TODO: add similar checks for SDIO */ + + return SDMMC_OK; +} |