circuitpython/lib/sdmmc/sdmmc_sd.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 <assert.h>

#include "sdmmc_common.h"

sdmmc_err_t sdmmc_init_sd_if_cond(sdmmc_card_t* card)
{
    /* SEND_IF_COND (CMD8) command is used to identify SDHC/SDXC cards.
     * SD v1 and non-SD cards will not respond to this command.
     */
    uint32_t host_ocr = get_host_ocr(card->host.io_voltage);
    sdmmc_err_t err = sdmmc_send_cmd_send_if_cond(card, host_ocr);
    if (err == SDMMC_OK) {
        ESP_LOGD(TAG, "SDHC/SDXC card");
        host_ocr |= SD_OCR_SDHC_CAP;
    } else if (err == SDMMC_ERR_TIMEOUT) {
        ESP_LOGD(TAG, "CMD8 timeout; not an SD v2.00 card");
    } else if (host_is_spi(card) && err == SDMMC_ERR_NOT_SUPPORTED) {
        ESP_LOGD(TAG, "CMD8 rejected; not an SD v2.00 card");
    } else {
        ESP_LOGE(TAG, "%s: send_if_cond (1) returned 0x%x", __func__, err);
        return err;
    }
    card->ocr = host_ocr;
    return SDMMC_OK;
}

sdmmc_err_t sdmmc_init_sd_blocklen(sdmmc_card_t* card)
{
    /* SDSC cards support configurable data block lengths.
     * We don't use this feature and set the block length to 512 bytes,
     * same as the block length for SDHC cards.
     */
    if ((card->ocr & SD_OCR_SDHC_CAP) == 0) {
        sdmmc_err_t err = sdmmc_send_cmd_set_blocklen(card, &card->csd);
        if (err != SDMMC_OK) {
            ESP_LOGE(TAG, "%s: set_blocklen returned 0x%x", __func__, err);
            return err;
        }
    }
    return SDMMC_OK;
}

sdmmc_err_t sdmmc_init_sd_scr(sdmmc_card_t* card)
{
    sdmmc_err_t err;
    /* Get the contents of SCR register: bus width and the version of SD spec
     * supported by the card.
     * In SD mode, this is the first command which uses D0 line. Errors at
     * this step usually indicate connection issue or lack of pull-up resistor.
     */
    err = sdmmc_send_cmd_send_scr(card, &card->scr);
    if (err != SDMMC_OK) {
        ESP_LOGE(TAG, "%s: send_scr (1) returned 0x%x", __func__, err);
        return err;
    }

    if ((card->scr.bus_width & SCR_SD_BUS_WIDTHS_4BIT)
            && (card->host.flags & SDMMC_HOST_FLAG_4BIT)) {
        card->log_bus_width = 2;
    } else {
        card->log_bus_width = 0;
    }
    return SDMMC_OK;
}

sdmmc_err_t sdmmc_init_sd_bus_width(sdmmc_card_t* card)
{
    int width = 1;
    if (card->log_bus_width == 2) {
        width = 4;
    } else if (card->log_bus_width == 3) {
        width = 8;
    }
    sdmmc_err_t err = sdmmc_send_cmd_set_bus_width(card, width);
    if (err != SDMMC_OK) {
        ESP_LOGE(TAG, "set_bus_width failed (0x%x)", err);
        return err;
    }
    return SDMMC_OK;
}

sdmmc_err_t sdmmc_init_sd_wait_data_ready(sdmmc_card_t* card)
{
    /* Wait for the card to be ready for data transfers */
    uint32_t status = 0;
    uint32_t count = 0;
    while (!host_is_spi(card) && !(status & MMC_R1_READY_FOR_DATA)) {
        // TODO: add some timeout here
        sdmmc_err_t err = sdmmc_send_cmd_send_status(card, &status);
        if (err != SDMMC_OK) {
            return err;
        }
        if (++count % 16 == 0) {
            ESP_LOGV(TAG, "waiting for card to become ready (%d)", count);
        }
    }
    return SDMMC_OK;
}

sdmmc_err_t sdmmc_send_cmd_switch_func(sdmmc_card_t* card,
        uint32_t mode, uint32_t group, uint32_t function,
        sdmmc_switch_func_rsp_t* resp)
{
    if (card->scr.sd_spec < SCR_SD_SPEC_VER_1_10 ||
        ((card->csd.card_command_class & SD_CSD_CCC_SWITCH) == 0)) {
            return SDMMC_ERR_NOT_SUPPORTED;
    }

    if (group == 0 ||
        group > SD_SFUNC_GROUP_MAX ||
        function > SD_SFUNC_FUNC_MAX) {
        return SDMMC_ERR_INVALID_ARG;
    }

    if (mode > 1) {
        return SDMMC_ERR_INVALID_ARG;
    }

    uint32_t group_shift = (group - 1) << 2;
    /* all functions which should not be affected are set to 0xf (no change) */
    uint32_t other_func_mask = (0x00ffffff & ~(0xf << group_shift));
    uint32_t func_val = (function << group_shift) | other_func_mask;

    sdmmc_command_t cmd = {
            .opcode = MMC_SWITCH,
            .flags = SCF_CMD_ADTC | SCF_CMD_READ | SCF_RSP_R1,
            .blklen = sizeof(sdmmc_switch_func_rsp_t),
            .data = resp->data,
            .datalen = sizeof(sdmmc_switch_func_rsp_t),
            .arg = (!!mode << 31) | func_val
    };

    sdmmc_err_t err = sdmmc_send_cmd(card, &cmd);
    if (err != SDMMC_OK) {
        ESP_LOGE(TAG, "%s: sdmmc_send_cmd returned 0x%x", __func__, err);
        return err;
    }
    sdmmc_flip_byte_order(resp->data, sizeof(sdmmc_switch_func_rsp_t));
    uint32_t resp_ver = SD_SFUNC_VER(resp->data);
    if (resp_ver == 0) {
        /* busy response is never sent */
    } else if (resp_ver == 1) {
        if (SD_SFUNC_BUSY(resp->data, group) & (1 << function)) {
            ESP_LOGD(TAG, "%s: response indicates function %d:%d is busy",
                    __func__, group, function);
            return SDMMC_ERR_BUSY;
        }
    } else {
        ESP_LOGD(TAG, "%s: got an invalid version of SWITCH_FUNC response: 0x%02x",
                __func__, resp_ver);
        return SDMMC_ERR_INVALID_RESPONSE;
    }
    return SDMMC_OK;
}

sdmmc_err_t sdmmc_enable_hs_mode(sdmmc_card_t* card)
{
    /* This will determine if the card supports SWITCH_FUNC command,
     * and high speed mode. If the cards supports both, this will enable
     * high speed mode at the card side.
     */
    if (card->scr.sd_spec < SCR_SD_SPEC_VER_1_10 ||
        ((card->csd.card_command_class & SD_CSD_CCC_SWITCH) == 0)) {
            return SDMMC_ERR_NOT_SUPPORTED;
    }
    sdmmc_switch_func_rsp_t response;

    sdmmc_err_t err = sdmmc_send_cmd_switch_func(card, 0, SD_ACCESS_MODE, 0, &response);
    if (err != SDMMC_OK) {
        ESP_LOGD(TAG, "%s: sdmmc_send_cmd_switch_func (1) returned 0x%x", __func__, err);
        return err;
    }
    uint32_t supported_mask = SD_SFUNC_SUPPORTED(response.data, 1);
    if ((supported_mask & BIT(SD_ACCESS_MODE_SDR25)) == 0) {
        return SDMMC_ERR_NOT_SUPPORTED;
    }
    err = sdmmc_send_cmd_switch_func(card, 1, SD_ACCESS_MODE, SD_ACCESS_MODE_SDR25, &response);
    if (err != SDMMC_OK) {
        ESP_LOGD(TAG, "%s: sdmmc_send_cmd_switch_func (2) returned 0x%x", __func__, err);
        return err;
    }

    return err;
}

sdmmc_err_t sdmmc_enable_hs_mode_and_check(sdmmc_card_t* card)
{
    /* All cards should support at least default speed */
    card->max_freq_khz = SDMMC_FREQ_DEFAULT;
    if (card->host.max_freq_khz <= card->max_freq_khz) {
        /* Host is configured to use low frequency, don't attempt to switch */
        card->max_freq_khz = card->host.max_freq_khz;
        return SDMMC_OK;
    }

    /* Try to enabled HS mode */
    sdmmc_err_t err = sdmmc_enable_hs_mode(card);
    if (err != SDMMC_OK) {
        return err;
    }
    /* HS mode has been enabled on the card.
     * Read CSD again, it should now indicate that the card supports
     * 50MHz clock.
     * Since SEND_CSD is allowed only in standby mode, and the card is currently in data transfer
     * mode, deselect the card first, then get the CSD, then select the card again. This step is
     * not required in SPI mode, since CMD7 (select_card) is not supported.
     */
    const bool is_spi = host_is_spi(card);
    if (!is_spi) {
        err = sdmmc_send_cmd_select_card(card, 0);
        if (err != SDMMC_OK) {
            ESP_LOGE(TAG, "%s: select_card (1) returned 0x%x", __func__, err);
            return err;
        }
    }
    err = sdmmc_send_cmd_send_csd(card, &card->csd);
    if (err != SDMMC_OK) {
        ESP_LOGE(TAG, "%s: send_csd returned 0x%x", __func__, err);
        return err;
    }
    if (!is_spi) {
        err = sdmmc_send_cmd_select_card(card, card->rca);
        if (err != SDMMC_OK) {
            ESP_LOGE(TAG, "%s: select_card (2) returned 0x%x", __func__, err);
            return err;
        }
    }

    if (card->csd.tr_speed != 50000000) {
        ESP_LOGW(TAG, "unexpected: after enabling HS mode, tr_speed=%d", card->csd.tr_speed);
        return SDMMC_ERR_NOT_SUPPORTED;
    }

    card->max_freq_khz = SDMMC_FREQ_HIGHSPEED;
    return SDMMC_OK;
}

sdmmc_err_t sdmmc_check_scr(sdmmc_card_t* card)
{
    /* If frequency switch has been performed, read SCR register one more time
     * and compare the result with the previous one. Use this simple check as
     * an indicator of potential signal integrity issues.
     */
    sdmmc_scr_t scr_tmp;
    sdmmc_err_t err = sdmmc_send_cmd_send_scr(card, &scr_tmp);
    if (err != SDMMC_OK) {
        ESP_LOGE(TAG, "%s: send_scr returned 0x%x", __func__, err);
        return err;
    }
    if (memcmp(&card->scr, &scr_tmp, sizeof(scr_tmp)) != 0) {
        ESP_LOGE(TAG, "got corrupted data after increasing clock frequency");
        return SDMMC_ERR_INVALID_RESPONSE;
    }
    return SDMMC_OK;
}

sdmmc_err_t sdmmc_init_spi_crc(sdmmc_card_t* card)
{
    /* In SD mode, CRC checks of data transfers are mandatory and performed
     * by the hardware. In SPI mode, CRC16 of data transfers is optional and
     * needs to be enabled.
     */
    assert(host_is_spi(card));
    sdmmc_err_t err = sdmmc_send_cmd_crc_on_off(card, true);
    if (err != SDMMC_OK) {
        ESP_LOGE(TAG, "%s: sdmmc_send_cmd_crc_on_off returned 0x%x", __func__, err);
        return err;
    }
    return SDMMC_OK;
}

sdmmc_err_t sdmmc_decode_cid(sdmmc_response_t resp, sdmmc_cid_t* out_cid)
{
    out_cid->mfg_id = SD_CID_MID(resp);
    out_cid->oem_id = SD_CID_OID(resp);
    SD_CID_PNM_CPY(resp, out_cid->name);
    out_cid->revision = SD_CID_REV(resp);
    out_cid->serial = SD_CID_PSN(resp);
    out_cid->date = SD_CID_MDT(resp);
    return SDMMC_OK;
}

sdmmc_err_t sdmmc_decode_csd(sdmmc_response_t response, sdmmc_csd_t* out_csd)
{
    out_csd->csd_ver = SD_CSD_CSDVER(response);
    switch (out_csd->csd_ver) {
    case SD_CSD_CSDVER_2_0:
        out_csd->capacity = SD_CSD_V2_CAPACITY(response);
        out_csd->read_block_len = SD_CSD_V2_BL_LEN;
        break;
    case SD_CSD_CSDVER_1_0:
        out_csd->capacity = SD_CSD_CAPACITY(response);
        out_csd->read_block_len = SD_CSD_READ_BL_LEN(response);
        break;
    default:
        ESP_LOGE(TAG, "unknown SD CSD structure version 0x%x", out_csd->csd_ver);
        return SDMMC_ERR_NOT_SUPPORTED;
    }
    out_csd->card_command_class = SD_CSD_CCC(response);
    int read_bl_size = 1 << out_csd->read_block_len;
    out_csd->sector_size = TSD_MIN(read_bl_size, 512);
    if (out_csd->sector_size < read_bl_size) {
        out_csd->capacity *= read_bl_size / out_csd->sector_size;
    }
    int speed = SD_CSD_SPEED(response);
    if (speed == SD_CSD_SPEED_50_MHZ) {
        out_csd->tr_speed = 50000000;
    } else {
        out_csd->tr_speed = 25000000;
    }
    return SDMMC_OK;
}

sdmmc_err_t sdmmc_decode_scr(uint32_t *raw_scr, sdmmc_scr_t* out_scr)
{
    sdmmc_response_t resp = { 0 };
    resp[1] = __builtin_bswap32(raw_scr[0]);
    resp[0] = __builtin_bswap32(raw_scr[1]);
    int ver = SCR_STRUCTURE(resp);
    if (ver != 0) {
        return SDMMC_ERR_NOT_SUPPORTED;
    }
    out_scr->sd_spec = SCR_SD_SPEC(resp);
    out_scr->bus_width = SCR_SD_BUS_WIDTHS(resp);
    return SDMMC_OK;
}