diff options
Diffstat (limited to 'circuitpython/shared-module/sdcardio/SDCard.c')
| -rw-r--r-- | circuitpython/shared-module/sdcardio/SDCard.c | 504 |
1 files changed, 504 insertions, 0 deletions
diff --git a/circuitpython/shared-module/sdcardio/SDCard.c b/circuitpython/shared-module/sdcardio/SDCard.c new file mode 100644 index 0000000..182eb0e --- /dev/null +++ b/circuitpython/shared-module/sdcardio/SDCard.c @@ -0,0 +1,504 @@ +/* + * This file is part of the Micro Python project, http://micropython.org/ + * + * The MIT License (MIT) + * + * Copyright (c) 2020 Jeff Epler for Adafruit Industries + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +// This implementation largely follows the structure of adafruit_sdcard.py + +#include "shared-bindings/busio/SPI.h" +#include "shared-bindings/digitalio/DigitalInOut.h" +#include "shared-bindings/sdcardio/SDCard.h" +#include "shared-bindings/time/__init__.h" +#include "shared-bindings/util.h" +#include "shared-module/sdcardio/SDCard.h" + +#include "py/mperrno.h" + +#if 0 +#define DEBUG_PRINT(...) ((void)mp_printf(&mp_plat_print,##__VA_ARGS__)) +#else +#define DEBUG_PRINT(...) ((void)0) +#endif + +#define CMD_TIMEOUT (200) + +#define R1_IDLE_STATE (1 << 0) +#define R1_ILLEGAL_COMMAND (1 << 2) + +#define TOKEN_CMD25 (0xFC) +#define TOKEN_STOP_TRAN (0xFD) +#define TOKEN_DATA (0xFE) + +STATIC bool lock_and_configure_bus(sdcardio_sdcard_obj_t *self) { + if (!common_hal_busio_spi_try_lock(self->bus)) { + return false; + } + common_hal_busio_spi_configure(self->bus, self->baudrate, 0, 0, 8); + common_hal_digitalio_digitalinout_set_value(&self->cs, false); + return true; +} + +STATIC void lock_bus_or_throw(sdcardio_sdcard_obj_t *self) { + if (!lock_and_configure_bus(self)) { + mp_raise_OSError(EAGAIN); + } +} + +STATIC void clock_card(sdcardio_sdcard_obj_t *self, int bytes) { + uint8_t buf[] = {0xff}; + common_hal_digitalio_digitalinout_set_value(&self->cs, true); + for (int i = 0; i < bytes; i++) { + common_hal_busio_spi_write(self->bus, buf, 1); + } +} + +STATIC void extraclock_and_unlock_bus(sdcardio_sdcard_obj_t *self) { + clock_card(self, 1); + common_hal_busio_spi_unlock(self->bus); +} + +static uint8_t CRC7(const uint8_t *data, uint8_t n) { + uint8_t crc = 0; + for (uint8_t i = 0; i < n; i++) { + uint8_t d = data[i]; + for (uint8_t j = 0; j < 8; j++) { + crc <<= 1; + if ((d & 0x80) ^ (crc & 0x80)) { + crc ^= 0x09; + } + d <<= 1; + } + } + return (crc << 1) | 1; +} + +#define READY_TIMEOUT_NS (300 * 1000 * 1000) // 300ms +STATIC int wait_for_ready(sdcardio_sdcard_obj_t *self) { + uint64_t deadline = common_hal_time_monotonic_ns() + READY_TIMEOUT_NS; + while (common_hal_time_monotonic_ns() < deadline) { + uint8_t b; + common_hal_busio_spi_read(self->bus, &b, 1, 0xff); + if (b == 0xff) { + return 0; + } + } + return -ETIMEDOUT; +} + +// Note: this is never called while "in cmd25" (in fact, it's only used by `exit_cmd25`) +STATIC bool cmd_nodata(sdcardio_sdcard_obj_t *self, int cmd, int response) { + uint8_t cmdbuf[2] = {cmd, 0xff}; + + assert(!self->in_cmd25); + + common_hal_busio_spi_write(self->bus, cmdbuf, sizeof(cmdbuf)); + + // Wait for the response (response[7] == response) + for (int i = 0; i < CMD_TIMEOUT; i++) { + common_hal_busio_spi_read(self->bus, cmdbuf, 1, 0xff); + if (cmdbuf[0] == response) { + return 0; + } + } + return -EIO; +} + + +STATIC int exit_cmd25(sdcardio_sdcard_obj_t *self) { + if (self->in_cmd25) { + DEBUG_PRINT("exit cmd25\n"); + self->in_cmd25 = false; + return cmd_nodata(self, TOKEN_STOP_TRAN, 0); + } + return 0; +} + +// In Python API, defaults are response=None, data_block=True, wait=True +STATIC int cmd(sdcardio_sdcard_obj_t *self, int cmd, int arg, void *response_buf, size_t response_len, bool data_block, bool wait) { + int r = exit_cmd25(self); + if (r < 0) { + return r; + } + + DEBUG_PRINT("cmd % 3d [%02x] arg=% 11d [%08x] len=%d%s%s\n", cmd, cmd, arg, arg, response_len, data_block ? " data" : "", wait ? " wait" : ""); + uint8_t cmdbuf[6]; + cmdbuf[0] = cmd | 0x40; + cmdbuf[1] = (arg >> 24) & 0xff; + cmdbuf[2] = (arg >> 16) & 0xff; + cmdbuf[3] = (arg >> 8) & 0xff; + cmdbuf[4] = arg & 0xff; + cmdbuf[5] = CRC7(cmdbuf, 5); + + if (wait) { + r = wait_for_ready(self); + if (r < 0) { + return r; + } + } + + common_hal_busio_spi_write(self->bus, cmdbuf, sizeof(cmdbuf)); + + // Wait for the response (response[7] == 0) + bool response_received = false; + for (int i = 0; i < CMD_TIMEOUT; i++) { + common_hal_busio_spi_read(self->bus, cmdbuf, 1, 0xff); + if ((cmdbuf[0] & 0x80) == 0) { + response_received = true; + break; + } + } + + if (!response_received) { + return -EIO; + } + + if (response_buf) { + + if (data_block) { + cmdbuf[1] = 0xff; + do { + // Wait for the start block byte + common_hal_busio_spi_read(self->bus, cmdbuf + 1, 1, 0xff); + } while (cmdbuf[1] != 0xfe); + } + + common_hal_busio_spi_read(self->bus, response_buf, response_len, 0xff); + + if (data_block) { + // Read and discard the CRC-CCITT checksum + common_hal_busio_spi_read(self->bus, cmdbuf + 1, 2, 0xff); + } + + } + + return cmdbuf[0]; +} + +STATIC int block_cmd(sdcardio_sdcard_obj_t *self, int cmd_, int block, void *response_buf, size_t response_len, bool data_block, bool wait) { + return cmd(self, cmd_, block * self->cdv, response_buf, response_len, true, true); +} + +STATIC const compressed_string_t *init_card_v1(sdcardio_sdcard_obj_t *self) { + for (int i = 0; i < CMD_TIMEOUT; i++) { + if (cmd(self, 41, 0, NULL, 0, true, true) == 0) { + return NULL; + } + } + return translate("timeout waiting for v1 card"); +} + +STATIC const compressed_string_t *init_card_v2(sdcardio_sdcard_obj_t *self) { + for (int i = 0; i < CMD_TIMEOUT; i++) { + uint8_t ocr[4]; + common_hal_time_delay_ms(50); + cmd(self, 58, 0, ocr, sizeof(ocr), false, true); + cmd(self, 55, 0, NULL, 0, true, true); + if (cmd(self, 41, 0x40000000, NULL, 0, true, true) == 0) { + cmd(self, 58, 0, ocr, sizeof(ocr), false, true); + if ((ocr[0] & 0x40) != 0) { + self->cdv = 1; + } + return NULL; + } + } + return translate("timeout waiting for v2 card"); +} + +STATIC const compressed_string_t *init_card(sdcardio_sdcard_obj_t *self) { + clock_card(self, 10); + + common_hal_digitalio_digitalinout_set_value(&self->cs, false); + + assert(!self->in_cmd25); + self->in_cmd25 = false; // should be false already + + // CMD0: init card: should return _R1_IDLE_STATE (allow 5 attempts) + { + bool reached_idle_state = false; + for (int i = 0; i < 5; i++) { + // do not call cmd with wait=true, because that will return + // prematurely if the idle state is not reached. we can't depend on + // this when the card is not yet in SPI mode + (void)wait_for_ready(self); + if (cmd(self, 0, 0, NULL, 0, true, false) == R1_IDLE_STATE) { + reached_idle_state = true; + break; + } + } + if (!reached_idle_state) { + return translate("no SD card"); + } + } + + // CMD8: determine card version + { + uint8_t rb7[4]; + int response = cmd(self, 8, 0x1AA, rb7, sizeof(rb7), false, true); + if (response == R1_IDLE_STATE) { + const compressed_string_t *result = init_card_v2(self); + if (result != NULL) { + return result; + } + } else if (response == (R1_IDLE_STATE | R1_ILLEGAL_COMMAND)) { + const compressed_string_t *result = init_card_v1(self); + if (result != NULL) { + return result; + } + } else { + DEBUG_PRINT("Reading card version, response=0x%02x\n", response); + return translate("couldn't determine SD card version"); + } + } + + // CMD9: get number of sectors + { + uint8_t csd[16]; + int response = cmd(self, 9, 0, csd, sizeof(csd), true, true); + if (response != 0) { + return translate("no response from SD card"); + } + int csd_version = (csd[0] & 0xC0) >> 6; + if (csd_version >= 2) { + return translate("SD card CSD format not supported"); + } + + if (csd_version == 1) { + self->sectors = ((csd[8] << 8 | csd[9]) + 1) * 1024; + } else { + uint32_t block_length = 1 << (csd[5] & 0xF); + uint32_t c_size = ((csd[6] & 0x3) << 10) | (csd[7] << 2) | ((csd[8] & 0xC) >> 6); + uint32_t mult = 1 << (((csd[9] & 0x3) << 1 | (csd[10] & 0x80) >> 7) + 2); + self->sectors = block_length / 512 * mult * (c_size + 1); + } + } + + // CMD16: set block length to 512 bytes + { + int response = cmd(self, 16, 512, NULL, 0, true, true); + if (response != 0) { + return translate("can't set 512 block size"); + } + } + + return NULL; +} + +void common_hal_sdcardio_sdcard_construct(sdcardio_sdcard_obj_t *self, busio_spi_obj_t *bus, const mcu_pin_obj_t *cs, int baudrate) { + self->bus = bus; + common_hal_digitalio_digitalinout_construct(&self->cs, cs); + common_hal_digitalio_digitalinout_switch_to_output(&self->cs, true, DRIVE_MODE_PUSH_PULL); + + self->cdv = 512; + self->sectors = 0; + self->baudrate = 250000; + + lock_bus_or_throw(self); + const compressed_string_t *result = init_card(self); + extraclock_and_unlock_bus(self); + + if (result != NULL) { + common_hal_digitalio_digitalinout_deinit(&self->cs); + mp_raise_OSError_msg(result); + } + + self->baudrate = baudrate; +} + +void common_hal_sdcardio_sdcard_deinit(sdcardio_sdcard_obj_t *self) { + if (!self->bus) { + return; + } + common_hal_sdcardio_sdcard_sync(self); + self->bus = 0; + common_hal_digitalio_digitalinout_deinit(&self->cs); +} + +STATIC void common_hal_sdcardio_check_for_deinit(sdcardio_sdcard_obj_t *self) { + if (!self->bus) { + raise_deinited_error(); + } +} + +int common_hal_sdcardio_sdcard_get_blockcount(sdcardio_sdcard_obj_t *self) { + common_hal_sdcardio_check_for_deinit(self); + return self->sectors; +} + +STATIC int readinto(sdcardio_sdcard_obj_t *self, void *buf, size_t size) { + uint8_t aux[2] = {0, 0}; + while (aux[0] != 0xfe) { + common_hal_busio_spi_read(self->bus, aux, 1, 0xff); + } + + common_hal_busio_spi_read(self->bus, buf, size, 0xff); + + // Read checksum and throw it away + common_hal_busio_spi_read(self->bus, aux, sizeof(aux), 0xff); + return 0; +} + +STATIC int readblocks(sdcardio_sdcard_obj_t *self, uint32_t start_block, mp_buffer_info_t *buf) { + uint32_t nblocks = buf->len / 512; + if (nblocks == 1) { + // Use CMD17 to read a single block + return block_cmd(self, 17, start_block, buf->buf, buf->len, true, true); + } else { + // Use CMD18 to read multiple blocks + int r = block_cmd(self, 18, start_block, NULL, 0, true, true); + if (r < 0) { + return r; + } + + uint8_t *ptr = buf->buf; + while (nblocks--) { + r = readinto(self, ptr, 512); + if (r < 0) { + return r; + } + ptr += 512; + } + + // End the multi-block read + r = cmd(self, 12, 0, NULL, 0, true, false); + + // Return first status 0 or last before card ready (0xff) + while (r != 0) { + uint8_t single_byte; + common_hal_busio_spi_read(self->bus, &single_byte, 1, 0xff); + if (single_byte & 0x80) { + return r; + } + r = single_byte; + } + } + return 0; +} + +int common_hal_sdcardio_sdcard_readblocks(sdcardio_sdcard_obj_t *self, uint32_t start_block, mp_buffer_info_t *buf) { + common_hal_sdcardio_check_for_deinit(self); + if (buf->len % 512 != 0) { + mp_raise_ValueError(translate("Buffer length must be a multiple of 512")); + } + + lock_and_configure_bus(self); + int r = readblocks(self, start_block, buf); + extraclock_and_unlock_bus(self); + return r; +} + +STATIC int _write(sdcardio_sdcard_obj_t *self, uint8_t token, void *buf, size_t size) { + wait_for_ready(self); + + uint8_t cmd[2]; + cmd[0] = token; + + common_hal_busio_spi_write(self->bus, cmd, 1); + common_hal_busio_spi_write(self->bus, buf, size); + + cmd[0] = cmd[1] = 0xff; + common_hal_busio_spi_write(self->bus, cmd, 2); + + // Check the response + // This differs from the traditional adafruit_sdcard handling, + // but adafruit_sdcard also ignored the return value of SDCard._write(!) + // so nobody noticed + // + // + // Response is as follows: + // x x x 0 STAT 1 + // 7 6 5 4 3..1 0 + // with STATUS 010 indicating "data accepted", and other status bit + // combinations indicating failure. + // In practice, I was seeing cmd[0] as 0xe5, indicating success + for (int i = 0; i < CMD_TIMEOUT; i++) { + common_hal_busio_spi_read(self->bus, cmd, 1, 0xff); + DEBUG_PRINT("i=%02d cmd[0] = 0x%02x\n", i, cmd[0]); + if ((cmd[0] & 0b00010001) == 0b00000001) { + if ((cmd[0] & 0x1f) != 0x5) { + return -EIO; + } else { + break; + } + } + } + + // Wait for the write to finish + do { + common_hal_busio_spi_read(self->bus, cmd, 1, 0xff); + } while (cmd[0] == 0); + + // Success + return 0; +} + +STATIC int writeblocks(sdcardio_sdcard_obj_t *self, uint32_t start_block, mp_buffer_info_t *buf) { + common_hal_sdcardio_check_for_deinit(self); + uint32_t nblocks = buf->len / 512; + + DEBUG_PRINT("cmd25? %d next_block %d start_block %d\n", self->in_cmd25, self->next_block, start_block); + + if (!self->in_cmd25 || start_block != self->next_block) { + DEBUG_PRINT("entering CMD25 at %d\n", (int)start_block); + // Use CMD25 to write multiple block + int r = block_cmd(self, 25, start_block, NULL, 0, true, true); + if (r < 0) { + return r; + } + self->in_cmd25 = true; + } + + self->next_block = start_block; + + uint8_t *ptr = buf->buf; + while (nblocks--) { + int r = _write(self, TOKEN_CMD25, ptr, 512); + if (r < 0) { + self->in_cmd25 = false; + return r; + } + self->next_block++; + ptr += 512; + } + + return 0; +} + +int common_hal_sdcardio_sdcard_sync(sdcardio_sdcard_obj_t *self) { + common_hal_sdcardio_check_for_deinit(self); + lock_and_configure_bus(self); + int r = exit_cmd25(self); + extraclock_and_unlock_bus(self); + return r; +} + +int common_hal_sdcardio_sdcard_writeblocks(sdcardio_sdcard_obj_t *self, uint32_t start_block, mp_buffer_info_t *buf) { + common_hal_sdcardio_check_for_deinit(self); + if (buf->len % 512 != 0) { + mp_raise_ValueError(translate("Buffer length must be a multiple of 512")); + } + lock_and_configure_bus(self); + int r = writeblocks(self, start_block, buf); + extraclock_and_unlock_bus(self); + return r; +} |