add circuitpython code

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;
+}