/* * Copyright (c) 2006 Uwe Stuehler * 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 #include "sdmmc_common.h" #include "esp_attr.h" #include "esp_compiler.h" #define CIS_TUPLE(NAME) (cis_tuple_t) {.code=CISTPL_CODE_##NAME, .name=#NAME, .func=&cis_tuple_func_default, } #define CIS_TUPLE_WITH_FUNC(NAME, FUNC) (cis_tuple_t) {.code=CISTPL_CODE_##NAME, .name=#NAME, .func=&(FUNC), } #define CIS_CHECK_SIZE(SIZE, MINIMAL) do {int store_size = (SIZE); if((store_size) < (MINIMAL)) return ESP_ERR_INVALID_SIZE;} while(0) #define CIS_CHECK_UNSUPPORTED(COND) do {if(!(COND)) return ESP_ERR_NOT_SUPPORTED;} while(0) #define CIS_GET_MINIMAL_SIZE 32 typedef esp_err_t (*cis_tuple_info_func_t)(const void* tuple_info, uint8_t* data, FILE* fp); typedef struct { int code; const char *name; cis_tuple_info_func_t func; } cis_tuple_t; static const char* TAG = "sdmmc_io"; static esp_err_t cis_tuple_func_default(const void* p, uint8_t* data, FILE* fp); static esp_err_t cis_tuple_func_manfid(const void* p, uint8_t* data, FILE* fp); static esp_err_t cis_tuple_func_cftable_entry(const void* p, uint8_t* data, FILE* fp); static esp_err_t cis_tuple_func_end(const void* p, uint8_t* data, FILE* fp); static const cis_tuple_t cis_table[] = { CIS_TUPLE(NULL), CIS_TUPLE(DEVICE), CIS_TUPLE(CHKSUM), CIS_TUPLE(VERS1), CIS_TUPLE(ALTSTR), CIS_TUPLE(CONFIG), CIS_TUPLE_WITH_FUNC(CFTABLE_ENTRY, cis_tuple_func_cftable_entry), CIS_TUPLE_WITH_FUNC(MANFID, cis_tuple_func_manfid), CIS_TUPLE(FUNCID), CIS_TUPLE(FUNCE), CIS_TUPLE(VENDER_BEGIN), CIS_TUPLE(VENDER_END), CIS_TUPLE(SDIO_STD), CIS_TUPLE(SDIO_EXT), CIS_TUPLE_WITH_FUNC(END, cis_tuple_func_end), }; esp_err_t sdmmc_io_reset(sdmmc_card_t* card) { uint8_t sdio_reset = CCCR_CTL_RES; esp_err_t err = sdmmc_io_rw_direct(card, 0, SD_IO_CCCR_CTL, SD_ARG_CMD52_WRITE, &sdio_reset); if (err == ESP_ERR_TIMEOUT || (host_is_spi(card) && err == ESP_ERR_NOT_SUPPORTED)) { /* Non-IO cards are allowed to time out (in SD mode) or * return "invalid command" error (in SPI mode). */ } else if (err == ESP_ERR_NOT_FOUND) { ESP_LOGD(TAG, "%s: card not present", __func__); return err; } else if (err != ESP_OK) { ESP_LOGE(TAG, "%s: unexpected return: 0x%x", __func__, err ); return err; } return ESP_OK; } esp_err_t sdmmc_init_io(sdmmc_card_t* card) { /* IO_SEND_OP_COND(CMD5), Determine if the card is an IO card. * Non-IO cards will not respond to this command. */ esp_err_t err = sdmmc_io_send_op_cond(card, 0, &card->ocr); if (err != ESP_OK) { ESP_LOGD(TAG, "%s: io_send_op_cond (1) returned 0x%x; not IO card", __func__, err); card->is_sdio = 0; card->is_mem = 1; } else { card->is_sdio = 1; if (card->ocr & SD_IO_OCR_MEM_PRESENT) { ESP_LOGD(TAG, "%s: Combination card", __func__); card->is_mem = 1; } else { ESP_LOGD(TAG, "%s: IO-only card", __func__); card->is_mem = 0; } card->num_io_functions = SD_IO_OCR_NUM_FUNCTIONS(card->ocr); ESP_LOGD(TAG, "%s: number of IO functions: %d", __func__, card->num_io_functions); if (card->num_io_functions == 0) { card->is_sdio = 0; } uint32_t host_ocr = get_host_ocr(card->host.io_voltage); host_ocr &= card->ocr; err = sdmmc_io_send_op_cond(card, host_ocr, &card->ocr); if (err != ESP_OK) { ESP_LOGE(TAG, "%s: sdmmc_io_send_op_cond (1) returned 0x%x", __func__, err); return err; } err = sdmmc_io_enable_int(card); if (err != ESP_OK) { ESP_LOGD(TAG, "%s: sdmmc_enable_int failed (0x%x)", __func__, err); } } return ESP_OK; } esp_err_t sdmmc_init_io_bus_width(sdmmc_card_t* card) { esp_err_t err; card->log_bus_width = 0; if (card->host.flags & SDMMC_HOST_FLAG_4BIT) { uint8_t card_cap = 0; err = sdmmc_io_rw_direct(card, 0, SD_IO_CCCR_CARD_CAP, SD_ARG_CMD52_READ, &card_cap); if (err != ESP_OK) { ESP_LOGE(TAG, "%s: sdmmc_io_rw_direct (read SD_IO_CCCR_CARD_CAP) returned 0x%0x", __func__, err); return err; } ESP_LOGD(TAG, "IO card capabilities byte: %02x", card_cap); if (!(card_cap & CCCR_CARD_CAP_LSC) || (card_cap & CCCR_CARD_CAP_4BLS)) { // This card supports 4-bit bus mode uint8_t bus_width = CCCR_BUS_WIDTH_4; err = sdmmc_io_rw_direct(card, 0, SD_IO_CCCR_BUS_WIDTH, SD_ARG_CMD52_WRITE, &bus_width); if (err != ESP_OK) { ESP_LOGE(TAG, "%s: sdmmc_io_rw_direct (write SD_IO_CCCR_BUS_WIDTH) returned 0x%0x", __func__, err); return err; } card->log_bus_width = 2; } } return ESP_OK; } esp_err_t sdmmc_io_enable_hs_mode(sdmmc_card_t* card) { /* If the host is configured to use low frequency, don't attempt to switch */ if (card->host.max_freq_khz < SDMMC_FREQ_DEFAULT) { card->max_freq_khz = card->host.max_freq_khz; return ESP_OK; } else if (card->host.max_freq_khz < SDMMC_FREQ_HIGHSPEED) { card->max_freq_khz = SDMMC_FREQ_DEFAULT; return ESP_OK; } /* For IO cards, do write + read operation on "High Speed" register, * setting EHS bit. If both EHS and SHS read back as set, then HS mode * has been enabled. */ uint8_t val = CCCR_HIGHSPEED_ENABLE; esp_err_t err = sdmmc_io_rw_direct(card, 0, SD_IO_CCCR_HIGHSPEED, SD_ARG_CMD52_WRITE | SD_ARG_CMD52_EXCHANGE, &val); if (err != ESP_OK) { ESP_LOGD(TAG, "%s: sdmmc_io_rw_direct returned 0x%x", __func__, err); return err; } ESP_LOGD(TAG, "%s: CCCR_HIGHSPEED=0x%02x", __func__, val); const uint8_t hs_mask = CCCR_HIGHSPEED_ENABLE | CCCR_HIGHSPEED_SUPPORT; if ((val & hs_mask) != hs_mask) { return ESP_ERR_NOT_SUPPORTED; } card->max_freq_khz = SDMMC_FREQ_HIGHSPEED; return ESP_OK; } esp_err_t sdmmc_io_send_op_cond(sdmmc_card_t* card, uint32_t ocr, uint32_t *ocrp) { esp_err_t err = ESP_OK; sdmmc_command_t cmd = { .flags = SCF_CMD_BCR | SCF_RSP_R4, .arg = ocr, .opcode = SD_IO_SEND_OP_COND }; for (size_t i = 0; i < 100; i++) { err = sdmmc_send_cmd(card, &cmd); if (err != ESP_OK) { break; } if ((MMC_R4(cmd.response) & SD_IO_OCR_MEM_READY) || ocr == 0) { break; } err = ESP_ERR_TIMEOUT; vTaskDelay(SDMMC_IO_SEND_OP_COND_DELAY_MS / portTICK_PERIOD_MS); } if (err == ESP_OK && ocrp != NULL) *ocrp = MMC_R4(cmd.response); return err; } esp_err_t sdmmc_io_rw_direct(sdmmc_card_t* card, int func, uint32_t reg, uint32_t arg, uint8_t *byte) { esp_err_t err; sdmmc_command_t cmd = { .flags = SCF_CMD_AC | SCF_RSP_R5, .arg = 0, .opcode = SD_IO_RW_DIRECT }; arg |= (func & SD_ARG_CMD52_FUNC_MASK) << SD_ARG_CMD52_FUNC_SHIFT; arg |= (reg & SD_ARG_CMD52_REG_MASK) << SD_ARG_CMD52_REG_SHIFT; arg |= (*byte & SD_ARG_CMD52_DATA_MASK) << SD_ARG_CMD52_DATA_SHIFT; cmd.arg = arg; err = sdmmc_send_cmd(card, &cmd); if (err != ESP_OK) { ESP_LOGV(TAG, "%s: sdmmc_send_cmd returned 0x%x", __func__, err); return err; } *byte = SD_R5_DATA(cmd.response); return ESP_OK; } esp_err_t sdmmc_io_read_byte(sdmmc_card_t* card, uint32_t function, uint32_t addr, uint8_t *out_byte) { esp_err_t ret = sdmmc_io_rw_direct(card, function, addr, SD_ARG_CMD52_READ, out_byte); if (unlikely(ret != ESP_OK)) { ESP_LOGE(TAG, "%s: sdmmc_io_rw_direct (read 0x%" PRIx32 ") returned 0x%x", __func__, addr, ret); } return ret; } esp_err_t sdmmc_io_write_byte(sdmmc_card_t* card, uint32_t function, uint32_t addr, uint8_t in_byte, uint8_t* out_byte) { uint8_t tmp_byte = in_byte; esp_err_t ret = sdmmc_io_rw_direct(card, function, addr, SD_ARG_CMD52_WRITE | SD_ARG_CMD52_EXCHANGE, &tmp_byte); if (unlikely(ret != ESP_OK)) { ESP_LOGE(TAG, "%s: sdmmc_io_rw_direct (write 0x%" PRIu32 ") returned 0x%x", __func__, addr, ret); return ret; } if (out_byte != NULL) { *out_byte = tmp_byte; } return ESP_OK; } esp_err_t sdmmc_io_rw_extended(sdmmc_card_t* card, int func, uint32_t reg, int arg, void *datap, size_t datalen) { esp_err_t err; const int buflen = (datalen + 3) & (~3); //round up to 4 sdmmc_command_t cmd = { .flags = SCF_CMD_AC | SCF_RSP_R5, .arg = 0, .opcode = SD_IO_RW_EXTENDED, .data = datap, .datalen = datalen, .buflen = buflen, .blklen = SDMMC_IO_BLOCK_SIZE /* TODO: read max block size from CIS */ }; esp_dma_mem_info_t dma_mem_info; card->host.get_dma_info(card->host.slot, &dma_mem_info); if (unlikely(datalen > 0 && !esp_dma_is_buffer_alignment_satisfied(datap, buflen, dma_mem_info))) { if (datalen > SDMMC_IO_BLOCK_SIZE || card->host.dma_aligned_buffer == NULL) { // User gives unaligned buffer while `SDMMC_HOST_FLAG_ALLOC_ALIGNED_BUF` not set. return ESP_ERR_INVALID_ARG; } memset(card->host.dma_aligned_buffer, 0xcc, SDMMC_IO_BLOCK_SIZE); memcpy(card->host.dma_aligned_buffer, datap, datalen); cmd.data = card->host.dma_aligned_buffer; cmd.buflen = SDMMC_IO_BLOCK_SIZE; } uint32_t count; /* number of bytes or blocks, depending on transfer mode */ if (arg & SD_ARG_CMD53_BLOCK_MODE) { if (cmd.datalen % cmd.blklen != 0) { return ESP_ERR_INVALID_SIZE; } count = cmd.datalen / cmd.blklen; } else { if (datalen > SDMMC_IO_BLOCK_SIZE) { /* TODO: split into multiple operations? */ return ESP_ERR_INVALID_SIZE; } if (datalen == SDMMC_IO_BLOCK_SIZE) { count = 0; // See 5.3.1 SDIO simplified spec } else { count = datalen; } cmd.blklen = datalen; } arg |= (func & SD_ARG_CMD53_FUNC_MASK) << SD_ARG_CMD53_FUNC_SHIFT; arg |= (reg & SD_ARG_CMD53_REG_MASK) << SD_ARG_CMD53_REG_SHIFT; arg |= (count & SD_ARG_CMD53_LENGTH_MASK) << SD_ARG_CMD53_LENGTH_SHIFT; cmd.arg = arg; if ((arg & SD_ARG_CMD53_WRITE) == 0) { cmd.flags |= SCF_CMD_READ; } err = sdmmc_send_cmd(card, &cmd); if (datalen > 0 && cmd.data == card->host.dma_aligned_buffer) { assert(datalen <= SDMMC_IO_BLOCK_SIZE); memcpy(datap, card->host.dma_aligned_buffer, datalen); } if (err != ESP_OK) { ESP_LOGE(TAG, "%s: sdmmc_send_cmd returned 0x%x", __func__, err); return err; } return ESP_OK; } esp_err_t sdmmc_io_read_bytes(sdmmc_card_t* card, uint32_t function, uint32_t addr, void* dst, size_t size) { /* host quirk: SDIO transfer with length not divisible by 4 bytes * has to be split into two transfers: one with aligned length, * the other one for the remaining 1-3 bytes. */ uint8_t *pc_dst = dst; while (size > 0) { size_t size_aligned = size & (~3); size_t will_transfer = size_aligned > 0 ? size_aligned : size; // Note: sdmmc_io_rw_extended has an internal timeout, // typically SDMMC_DEFAULT_CMD_TIMEOUT_MS esp_err_t err = sdmmc_io_rw_extended(card, function, addr, SD_ARG_CMD53_READ | SD_ARG_CMD53_INCREMENT, pc_dst, will_transfer); if (unlikely(err != ESP_OK)) { return err; } pc_dst += will_transfer; size -= will_transfer; addr += will_transfer; } return ESP_OK; } esp_err_t sdmmc_io_write_bytes(sdmmc_card_t* card, uint32_t function, uint32_t addr, const void* src, size_t size) { /* same host quirk as in sdmmc_io_read_bytes */ const uint8_t *pc_src = (const uint8_t*) src; while (size > 0) { size_t size_aligned = size & (~3); size_t will_transfer = size_aligned > 0 ? size_aligned : size; // Note: sdmmc_io_rw_extended has an internal timeout, // typically SDMMC_DEFAULT_CMD_TIMEOUT_MS esp_err_t err = sdmmc_io_rw_extended(card, function, addr, SD_ARG_CMD53_WRITE | SD_ARG_CMD53_INCREMENT, (void*) pc_src, will_transfer); if (unlikely(err != ESP_OK)) { return err; } pc_src += will_transfer; size -= will_transfer; addr += will_transfer; } return ESP_OK; } esp_err_t sdmmc_io_read_blocks(sdmmc_card_t* card, uint32_t function, uint32_t addr, void* dst, size_t size) { esp_dma_mem_info_t dma_mem_info; card->host.get_dma_info(card->host.slot, &dma_mem_info); if (unlikely(!esp_dma_is_buffer_alignment_satisfied(dst, size, dma_mem_info))) { return ESP_ERR_INVALID_ARG; } return sdmmc_io_rw_extended(card, function, addr, SD_ARG_CMD53_READ | SD_ARG_CMD53_INCREMENT | SD_ARG_CMD53_BLOCK_MODE, dst, size); } esp_err_t sdmmc_io_write_blocks(sdmmc_card_t* card, uint32_t function, uint32_t addr, const void* src, size_t size) { esp_dma_mem_info_t dma_mem_info; card->host.get_dma_info(card->host.slot, &dma_mem_info); if (unlikely(!esp_dma_is_buffer_alignment_satisfied(src, size, dma_mem_info))) { return ESP_ERR_INVALID_ARG; } return sdmmc_io_rw_extended(card, function, addr, SD_ARG_CMD53_WRITE | SD_ARG_CMD53_INCREMENT | SD_ARG_CMD53_BLOCK_MODE, (void*) src, size); } esp_err_t sdmmc_io_enable_int(sdmmc_card_t* card) { if (card->host.io_int_enable == NULL) { return ESP_ERR_NOT_SUPPORTED; } return (*card->host.io_int_enable)(card->host.slot); } esp_err_t sdmmc_io_wait_int(sdmmc_card_t* card, TickType_t timeout_ticks) { if (card->host.io_int_wait == NULL) { return ESP_ERR_NOT_SUPPORTED; } return (*card->host.io_int_wait)(card->host.slot, timeout_ticks); } /* * Print the CIS information of a CIS card, currently only ESP slave supported. */ static esp_err_t cis_tuple_func_default(const void* p, uint8_t* data, FILE* fp) { const cis_tuple_t* tuple = (const cis_tuple_t*)p; uint8_t code = *(data++); int size = *(data++); if (tuple) { fprintf(fp, "TUPLE: %s, size: %d: ", tuple->name, size); } else { fprintf(fp, "TUPLE: unknown(%02X), size: %d: ", code, size); } for (int i = 0; i < size; i++) fprintf(fp, "%02X ", *(data++)); fprintf(fp, "\n"); return ESP_OK; } static esp_err_t cis_tuple_func_manfid(const void* p, uint8_t* data, FILE* fp) { const cis_tuple_t* tuple = (const cis_tuple_t*)p; data++; int size = *(data++); fprintf(fp, "TUPLE: %s, size: %d\n", tuple->name, size); CIS_CHECK_SIZE(size, 4); fprintf(fp, " MANF: %04X, CARD: %04X\n", *(uint16_t*)(data), *(uint16_t*)(data+2)); return ESP_OK; } static esp_err_t cis_tuple_func_end(const void* p, uint8_t* data, FILE* fp) { const cis_tuple_t* tuple = (const cis_tuple_t*)p; fprintf(fp, "TUPLE: %s\n", tuple->name); return ESP_OK; } static esp_err_t cis_tuple_func_cftable_entry(const void* p, uint8_t* data, FILE* fp) { const cis_tuple_t* tuple = (const cis_tuple_t*)p; data++; int size = *(data++); fprintf(fp, "TUPLE: %s, size: %d\n", tuple->name, size); CIS_CHECK_SIZE(size, 2); CIS_CHECK_SIZE(size--, 1); bool interface = data[0] & BIT(7); bool def = data[0] & BIT(6); int conf_ent_num = data[0] & 0x3F; fprintf(fp, " INDX: %02X, Intface: %d, Default: %d, Conf-Entry-Num: %d\n", *(data++), interface, def, conf_ent_num); if (interface) { CIS_CHECK_SIZE(size--, 1); fprintf(fp, " IF: %02X\n", *(data++)); } CIS_CHECK_SIZE(size--, 1); bool misc = data[0] & BIT(7); int mem_space = (data[0] >> 5 )&(0x3); bool irq = data[0] & BIT(4); bool io_sp = data[0] & BIT(3); bool timing = data[0] & BIT(2); int power = data[0] & 3; fprintf(fp, " FS: %02X, misc: %d, mem_space: %d, irq: %d, io_space: %d, timing: %d, power: %d\n", *(data++), misc, mem_space, irq, io_sp, timing, power); CIS_CHECK_UNSUPPORTED(power == 0); //power descriptor is not handled yet CIS_CHECK_UNSUPPORTED(!timing); //timing descriptor is not handled yet CIS_CHECK_UNSUPPORTED(!io_sp); //io space descriptor is not handled yet if (irq) { CIS_CHECK_SIZE(size--, 1); bool mask = data[0] & BIT(4); fprintf(fp, " IR: %02X, mask: %d, ",*(data++), mask); if (mask) { CIS_CHECK_SIZE(size, 2); size-=2; fprintf(fp, " IRQ: %02X %02X\n", data[0], data[1]); data+=2; } } if (mem_space) { CIS_CHECK_SIZE(size, 2); size-=2; CIS_CHECK_UNSUPPORTED(mem_space==1); //other cases not handled yet int len = *(uint16_t*)data; fprintf(fp, " LEN: %04X\n", len); data+=2; } CIS_CHECK_UNSUPPORTED(misc==0); //misc descriptor is not handled yet return ESP_OK; } static const cis_tuple_t* get_tuple(uint8_t code) { for (int i = 0; i < sizeof(cis_table)/sizeof(cis_tuple_t); i++) { if (code == cis_table[i].code) return &cis_table[i]; } return NULL; } esp_err_t sdmmc_io_print_cis_info(uint8_t* buffer, size_t buffer_size, FILE* fp) { ESP_LOG_BUFFER_HEXDUMP("CIS", buffer, buffer_size, ESP_LOG_DEBUG); if (!fp) fp = stdout; uint8_t* cis = buffer; do { const cis_tuple_t* tuple = get_tuple(cis[0]); int size = cis[1]; esp_err_t ret = ESP_OK; if (tuple) { ret = tuple->func(tuple, cis, fp); } else { ret = cis_tuple_func_default(NULL, cis, fp); } if (ret != ESP_OK) return ret; cis += 2 + size; if (tuple && tuple->code == CISTPL_CODE_END) break; } while (cis < buffer + buffer_size) ; return ESP_OK; } /** * Check tuples in the buffer. * * @param buf Buffer to check * @param buffer_size Size of the buffer * @param inout_cis_offset * - input: the last cis_offset, relative to the beginning of the buf. -1 if * this buffer begin with the tuple length, otherwise should be no smaller than * zero. * - output: when the end tuple found, output offset of the CISTPL_CODE_END * byte + 1 (relative to the beginning of the buffer; when not found, output * the address of next tuple code. * * @return true if found, false if haven't. */ static bool check_tuples_in_buffer(uint8_t* buf, int buffer_size, int* inout_cis_offset) { int cis_offset = *inout_cis_offset; if (cis_offset == -1) { //the CIS code is checked in the last buffer, skip to next tuple cis_offset += buf[0] + 2; } assert(cis_offset >= 0); while (1) { if (cis_offset < buffer_size) { //A CIS code in the buffer, check it if (buf[cis_offset] == CISTPL_CODE_END) { *inout_cis_offset = cis_offset + 1; return true; } } if (cis_offset + 1 < buffer_size) { cis_offset += buf[cis_offset+1] + 2; } else { break; } } *inout_cis_offset = cis_offset; return false; } esp_err_t sdmmc_io_get_cis_data(sdmmc_card_t* card, uint8_t* out_buffer, size_t buffer_size, size_t* inout_cis_size) { esp_err_t ret = ESP_OK; WORD_ALIGNED_ATTR uint8_t buf[CIS_GET_MINIMAL_SIZE]; /* Pointer to size is a mandatory parameter */ assert(inout_cis_size); /* * CIS region exist in 0x1000~0x17FFF of FUNC 0, get the start address of it * from CCCR register. */ uint32_t addr; ret = sdmmc_io_read_bytes(card, 0, 9, &addr, 3); if (ret != ESP_OK) return ret; //the sdmmc_io driver reads 4 bytes, the most significant byte is not the address. addr &= 0xffffff; if (addr < 0x1000 || addr > 0x17FFF) { return ESP_ERR_INVALID_RESPONSE; } /* * To avoid reading too long, take the input value as limitation if * existing. */ size_t max_reading = UINT32_MAX; if (*inout_cis_size != 0) { max_reading = *inout_cis_size; } /* * Parse the length while reading. If find the end tuple, or reaches the * limitation, read no more and return both the data and the size already * read. */ int buffer_offset = 0; int cur_cis_offset = 0; bool end_tuple_found = false; do { ret = sdmmc_io_read_bytes(card, 0, addr + buffer_offset, &buf, CIS_GET_MINIMAL_SIZE); if (ret != ESP_OK) return ret; //calculate relative to the beginning of the buffer int offset = cur_cis_offset - buffer_offset; bool finish = check_tuples_in_buffer(buf, CIS_GET_MINIMAL_SIZE, &offset); int remain_size = buffer_size - buffer_offset; int copy_len; if (finish) { copy_len = MIN(offset, remain_size); end_tuple_found = true; } else { copy_len = MIN(CIS_GET_MINIMAL_SIZE, remain_size); } if (copy_len > 0) { memcpy(out_buffer + buffer_offset, buf, copy_len); } cur_cis_offset = buffer_offset + offset; buffer_offset += CIS_GET_MINIMAL_SIZE; } while (!end_tuple_found && buffer_offset < max_reading); if (end_tuple_found) { *inout_cis_size = cur_cis_offset; if (cur_cis_offset > buffer_size) { return ESP_ERR_INVALID_SIZE; } else { return ESP_OK; } } else { return ESP_ERR_NOT_FOUND; } }