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circuitpython/shared-module/sdcardio/SDCard.c

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/*
* 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 mp_rom_error_text_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 MP_ERROR_TEXT("timeout waiting for v1 card");
}
STATIC mp_rom_error_text_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 MP_ERROR_TEXT("timeout waiting for v2 card");
}
STATIC mp_rom_error_text_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 MP_ERROR_TEXT("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) {
mp_rom_error_text_t result = init_card_v2(self);
if (result != NULL) {
return result;
}
} else if (response == (R1_IDLE_STATE | R1_ILLEGAL_COMMAND)) {
mp_rom_error_text_t result = init_card_v1(self);
if (result != NULL) {
return result;
}
} else {
DEBUG_PRINT("Reading card version, response=0x%02x\n", response);
return MP_ERROR_TEXT("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 MP_ERROR_TEXT("no response from SD card");
}
int csd_version = (csd[0] & 0xC0) >> 6;
if (csd_version >= 2) {
return MP_ERROR_TEXT("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 MP_ERROR_TEXT("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);
mp_rom_error_text_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(MP_ERROR_TEXT("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(MP_ERROR_TEXT("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;
}
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