diff options
Diffstat (limited to 'src/drivers/ao_sdcard.c')
| -rw-r--r-- | src/drivers/ao_sdcard.c | 398 |
1 files changed, 398 insertions, 0 deletions
diff --git a/src/drivers/ao_sdcard.c b/src/drivers/ao_sdcard.c new file mode 100644 index 00000000..2174af1e --- /dev/null +++ b/src/drivers/ao_sdcard.c @@ -0,0 +1,398 @@ +/* + * Copyright © 2013 Keith Packard <keithp@keithp.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + */ + +#include "ao.h" +#include "ao_sdcard.h" + +#define ao_sdcard_get_slow() ao_spi_get(AO_SDCARD_SPI_BUS, AO_SPI_SPEED_250kHz) +#define ao_sdcard_get() ao_spi_get(AO_SDCARD_SPI_BUS, AO_SPI_SPEED_FAST) +#define ao_sdcard_put() ao_spi_put(AO_SDCARD_SPI_BUS) +#define ao_sdcard_send_fixed(d,l) ao_spi_send_fixed((d), (l), AO_SDCARD_SPI_BUS) +#define ao_sdcard_send(d,l) ao_spi_send((d), (l), AO_SDCARD_SPI_BUS) +#define ao_sdcard_recv(d,l) ao_spi_recv((d), (l), AO_SDCARD_SPI_BUS) +#define ao_sdcard_select() ao_gpio_set(AO_SDCARD_SPI_CS_PORT,AO_SDCARD_SPI_CS_PIN,AO_SDCARD_SPI_CS,0) +#define ao_sdcard_deselect() ao_gpio_set(AO_SDCARD_SPI_CS_PORT,AO_SDCARD_SPI_CS_PIN,AO_SDCARD_SPI_CS,1) + + +static uint8_t initialized; +static uint8_t present; +static uint8_t mutex; +static enum ao_sdtype sdtype; + +#define ao_sdcard_lock() ao_mutex_get(&mutex) +#define ao_sdcard_unlock() ao_mutex_put(&mutex) + +#if 0 +#define DBG(...) printf(__VA_ARGS__) +#else +#define DBG(...) +#endif + +/* + * Send an SD command and await the status reply + */ + +static uint8_t +ao_sdcard_send_cmd(uint8_t cmd, uint32_t arg) +{ + uint8_t data[6]; + uint8_t reply; + int i; + + DBG ("\tsend_cmd %d arg %08x\n", cmd, arg); + if (cmd != SDCARD_GO_IDLE_STATE) { + for (i = 0; i < SDCARD_CMD_TIMEOUT; i++) { + ao_sdcard_recv(&reply, 1); + if (reply == 0xff) + break; + } + if (i == SDCARD_CMD_TIMEOUT) + return SDCARD_STATUS_TIMEOUT; + } + + data[0] = cmd & 0x3f | 0x40; + data[1] = arg >> 24; + data[2] = arg >> 16; + data[3] = arg >> 8; + data[4] = arg; + if (cmd == SDCARD_GO_IDLE_STATE) + data[5] = 0x95; /* Valid for 0 arg */ + else if (cmd == SDCARD_SEND_IF_COND) + data[5] = 0x87; /* Valid for 0x1aa arg */ + else + data[5] = 0xff; /* no CRC */ + ao_sdcard_send(data, 6); + + /* The first reply byte will be the status, + * which must have the high bit clear + */ + for (i = 0; i < SDCARD_CMD_TIMEOUT; i++) { + ao_sdcard_recv(&reply, 1); + DBG ("\t\tgot byte %02x\n", reply); + if ((reply & 0x80) == 0) + return reply; + } + return SDCARD_STATUS_TIMEOUT; +} + +/* + * Retrieve any reply, discarding the trailing CRC byte + */ +static void +ao_sdcard_recv_reply(uint8_t *reply, int len) +{ + uint8_t discard; + + if (len) + ao_sdcard_recv(reply, len); + /* trailing byte */ + ao_sdcard_recv(&discard, 1); +} + +/* + * Wait while the card is busy. The + * card will return a stream of 0xff + * until it isn't busy anymore + */ +static void +ao_sdcard_wait_busy(void) +{ + uint8_t v; + + do { + ao_sdcard_recv(&v, 1); + } while (v != 0xff); + ao_sdcard_send_fixed(0xff, 1); +} + +static uint8_t +ao_sdcard_go_idle_state(void) +{ + uint8_t ret; + + DBG ("go_idle_state\n"); + ao_sdcard_select(); + ret = ao_sdcard_send_cmd(SDCARD_GO_IDLE_STATE, 0); + ao_sdcard_recv_reply(NULL, 0); + ao_sdcard_deselect(); + DBG ("\tgo_idle_state status %02x\n", ret); + return ret; +} + +static uint8_t +ao_sdcard_send_op_cond(void) +{ + uint8_t ret; + + DBG ("send_op_cond\n"); + ao_sdcard_select(); + ret = ao_sdcard_send_cmd(SDCARD_SEND_OP_COND, 0); + ao_sdcard_recv_reply(NULL, 0); + ao_sdcard_deselect(); + DBG ("\tsend_op_cond %02x\n", ret); + return ret; +} + +static uint8_t +ao_sdcard_send_if_cond(uint32_t arg, uint8_t send_if_cond_response[4]) +{ + uint8_t ret; + + DBG ("send_if_cond\n"); + ao_sdcard_select(); + ret = ao_sdcard_send_cmd(SDCARD_SEND_IF_COND, arg); + if (ret != SDCARD_STATUS_IDLE_STATE) { + DBG ("\tsend_if_cond failed %02x\n", ret); + return ret; + } + ao_sdcard_recv_reply(send_if_cond_response, 4); + DBG ("send_if_cond status %02x response %02x %02x %02x %02x\n", + ret, + send_if_cond_response[0], + send_if_cond_response[1], + send_if_cond_response[2], + send_if_cond_response[3]); + ao_sdcard_deselect(); + return ret; +} + +static uint8_t +ao_sdcard_set_blocklen(uint32_t blocklen) +{ + uint8_t ret; + + DBG ("set_blocklen %d\n", blocklen); + ao_sdcard_select(); + ret = ao_sdcard_send_cmd(SDCARD_SET_BLOCKLEN, blocklen); + ao_sdcard_recv_reply(NULL, 0); + if (ret != SDCARD_STATUS_READY_STATE) + DBG ("\tsend_if_cond failed %02x\n", ret); + return ret; + +} + +static uint8_t +ao_sdcard_app_cmd(void) +{ + uint8_t ret; + + DBG ("app_cmd\n"); + ao_sdcard_select(); + ret = ao_sdcard_send_cmd(SDCARD_APP_CMD, 0); + ao_sdcard_recv_reply(NULL, 0); + ao_sdcard_deselect(); + DBG ("\tapp_cmd status %02x\n"); + return ret; +} + +static uint8_t +ao_sdcard_app_send_op_cond(uint32_t arg) +{ + uint8_t ret; + + ret = ao_sdcard_app_cmd(); + if (ret != SDCARD_STATUS_IDLE_STATE) + return ret; + DBG("send_op_comd\n"); + ao_sdcard_select(); + ret = ao_sdcard_send_cmd(SDCARD_APP_SEND_OP_COMD, arg); + ao_sdcard_recv_reply(NULL, 0); + ao_sdcard_deselect(); + DBG ("\tapp_send_op_cond status %02x\n", ret); + return ret; +} + +static uint8_t +ao_sdcard_read_ocr(uint8_t read_ocr_response[4]) +{ + uint8_t ret; + + DBG ("read_ocr\n"); + ao_sdcard_select(); + ret = ao_sdcard_send_cmd(SDCARD_READ_OCR, 0); + if (ret != SDCARD_STATUS_READY_STATE) + DBG ("\tread_ocr failed %02x\n", ret); + else { + ao_sdcard_recv_reply(read_ocr_response, 4); + DBG ("\tread_ocr status %02x response %02x %02x %02x %02x\n", ret, + read_ocr_response[0], read_ocr_response[1], + read_ocr_response[2], read_ocr_response[3]); + } + ao_sdcard_deselect(); + return ret; +} + +static void +ao_sdcard_setup(void) +{ + int i; + uint8_t ret; + uint8_t response[10]; + + DBG ("Testing sdcard\n"); + + ao_sdcard_get_slow(); + /* + * min 74 clocks with CS high + */ + ao_sdcard_send_fixed(0xff, 10); + + ao_delay(AO_MS_TO_TICKS(10)); + + /* Reset the card and get it into SPI mode */ + + for (i = 0; i < SDCARD_IDLE_WAIT; i++) { + if (ao_sdcard_go_idle_state() == SDCARD_STATUS_IDLE_STATE) + break; + } + if (i == SDCARD_IDLE_WAIT) + goto bail; + + /* Figure out what kind of card we have */ + + sdtype = ao_sdtype_unknown; + + if (ao_sdcard_send_if_cond(0x1aa, response) == SDCARD_STATUS_IDLE_STATE) { + uint32_t arg = 0; + uint8_t sdver2 = 0; + + /* Check for SD version 2 */ + if ((response[2] & 0xf) == 1 && response[3] == 0xaa) { + arg = 0x40000000; + sdver2 = 1; + } + + for (i = 0; i < SDCARD_IDLE_WAIT; i++) { + ret = ao_sdcard_app_send_op_cond(arg); + if (ret != SDCARD_STATUS_IDLE_STATE) + break; + } + if (ret != SDCARD_STATUS_READY_STATE) { + /* MMC */ + for (i = 0; i < SDCARD_IDLE_WAIT; i++) { + ret = ao_sdcard_send_op_cond(); + if (ret != SDCARD_STATUS_IDLE_STATE) + break; + } + if (ret != SDCARD_STATUS_READY_STATE) + goto bail; + sdtype = ao_sdtype_mmc3; + } else { + /* SD */ + if (sdver2 != 0) { + ret = ao_sdcard_read_ocr(response); + if (ret != SDCARD_STATUS_READY_STATE) + goto bail; + if ((response[0] & 0xc0) == 0xc0) + sdtype = ao_sdtype_sd2block; + else + sdtype = ao_sdtype_sd2byte; + } else { + sdtype = ao_sdtype_sd1; + } + } + + /* For everything but SDHC cards, set the block length */ + if (sdtype != ao_sdtype_sd2block) { + ret = ao_sdcard_set_blocklen(512); + if (ret != SDCARD_STATUS_READY_STATE) + DBG ("set_blocklen failed, ignoring\n"); + } + } + + DBG ("SD card detected, type %d\n", sdtype); +bail: + ao_sdcard_put(); +} + +static uint8_t +ao_sdcard_wait_block_start(void) +{ + int i; + uint8_t v; + + DBG ("\twait_block_start\n"); + for (i = 0; i < SDCARD_BLOCK_TIMEOUT; i++) { + ao_sdcard_recv(&v, 1); + DBG("\t\trecv %02x\n", v); + if (v != 0xff) + break; + } + return v; +} + +/* + * Read a block of 512 bytes from the card + */ +uint8_t +ao_sdcard_read_block(uint32_t block, uint8_t *data) +{ + uint8_t ret; + uint8_t crc[2]; + + ao_sdcard_lock(); + if (!initialized) { + ao_sdcard_setup(); + initialized = 1; + if (sdtype != ao_sdtype_unknown) + present = 1; + } + if (!present) { + ao_sdcard_unlock(); + return 0; + } + if (sdtype != ao_sdtype_sd2block) + block <<= 9; + ao_sdcard_get(); + ao_sdcard_select(); + ret = ao_sdcard_send_cmd(SDCARD_READ_BLOCK, block); + ao_sdcard_recv_reply(NULL, 0); + if (ret != SDCARD_STATUS_READY_STATE) + goto bail; + + if (ao_sdcard_wait_block_start() != 0xfe) { + ret = 0x3f; + goto bail; + } + + ao_sdcard_recv(data, 512); + ao_sdcard_recv(crc, 2); +bail: + ao_sdcard_deselect(); + ao_sdcard_put(); + ao_sdcard_unlock(); + return ret == SDCARD_STATUS_READY_STATE; +} + +/* + * Write a block of 512 bytes to the card + */ +uint8_t +ao_sdcard_write_block(uint32_t block, uint8_t *data) +{ + /* Not doing anything until the file system code seems reasonable + */ + return 1; +} + +void +ao_sdcard_init(void) +{ + ao_spi_init_cs(AO_SDCARD_SPI_CS_PORT, (1 << AO_SDCARD_SPI_CS_PIN)); +} + + |