Diff: libpff/mmc.c

Revision:

0:b5453be5ad07

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libpff/mmc.c	Tue Jun 01 12:23:29 2010 +0000
@@ -0,0 +1,268 @@
+/*-----------------------------------------------------------------------*/
+/* PFF - Low level disk control module for ATtiny85     (C)ChaN, 2009    */
+/*-----------------------------------------------------------------------*/
+
+#define _WRITE_FUNC    1
+
+#include "diskio.h"
+#include "mbed.h"
+#include "connect.h"
+
+/* Definitions for MMC/SDC command */
+#define CMD0    (0x40+0)    /* GO_IDLE_STATE */
+#define CMD1    (0x40+1)    /* SEND_OP_COND (MMC) */
+#define    ACMD41    (0xC0+41)    /* SEND_OP_COND (SDC) */
+#define CMD8    (0x40+8)    /* SEND_IF_COND */
+#define CMD16    (0x40+16)    /* SET_BLOCKLEN */
+#define CMD17    (0x40+17)    /* READ_SINGLE_BLOCK */
+#define CMD24    (0x40+24)    /* WRITE_BLOCK */
+#define CMD55    (0x40+55)    /* APP_CMD */
+#define CMD58    (0x40+58)    /* READ_OCR */
+
+SPI device(CONNECT_MOSI,CONNECT_MISO,CONNECT_SCK);
+DigitalOut cs(CONNECT_CS);
+
+/* Port Controls (Platform dependent) */
+#define SELECT()    cs.write(0)        /* MMC CS = L */
+#define    DESELECT()    cs.write(1)        /* MMC CS = H */
+#define    MMC_SEL        !cs.read()    /* MMC CS status (true:selected) */
+
+void xmit_spi (BYTE c) {
+    device.write(c);    /* Send a byte */
+}
+
+BYTE rcv_spi (void) {
+    return device.write(0xff);
+}
+
+/*--------------------------------------------------------------------------
+
+   Module Private Functions
+
+---------------------------------------------------------------------------*/
+
+static
+BYTE CardType;
+
+
+/*-----------------------------------------------------------------------*/
+/* Deselect the card and release SPI bus                                 */
+/*-----------------------------------------------------------------------*/
+
+static
+void release_spi (void) {
+    DESELECT();
+    rcv_spi();
+}
+
+
+/*-----------------------------------------------------------------------*/
+/* Send a command packet to MMC                                          */
+/*-----------------------------------------------------------------------*/
+
+static
+BYTE send_cmd (
+    BYTE cmd,        /* Command byte */
+    DWORD arg        /* Argument */
+) {
+    BYTE n, res;
+
+
+    if (cmd & 0x80) {    /* ACMD<n> is the command sequense of CMD55-CMD<n> */
+        cmd &= 0x7F;
+        res = send_cmd(CMD55, 0);
+        if (res > 1) return res;
+    }
+
+    /* Select the card */
+    DESELECT();
+    rcv_spi();
+    SELECT();
+    rcv_spi();
+
+    /* Send a command packet */
+    xmit_spi(cmd);                        /* Start + Command index */
+    xmit_spi((BYTE)(arg >> 24));        /* Argument[31..24] */
+    xmit_spi((BYTE)(arg >> 16));        /* Argument[23..16] */
+    xmit_spi((BYTE)(arg >> 8));            /* Argument[15..8] */
+    xmit_spi((BYTE)arg);                /* Argument[7..0] */
+    n = 0x01;                            /* Dummy CRC + Stop */
+    if (cmd == CMD0) n = 0x95;            /* Valid CRC for CMD0(0) */
+    if (cmd == CMD8) n = 0x87;            /* Valid CRC for CMD8(0x1AA) */
+    xmit_spi(n);
+
+    /* Receive a command response */
+    n = 10;                                /* Wait for a valid response in timeout of 10 attempts */
+    do {
+        res = rcv_spi();
+    } while ((res & 0x80) && --n);
+
+    return res;            /* Return with the response value */
+}
+
+
+
+/*--------------------------------------------------------------------------
+
+   Public Functions
+
+---------------------------------------------------------------------------*/
+
+
+/*-----------------------------------------------------------------------*/
+/* Initialize Disk Drive                                                 */
+/*-----------------------------------------------------------------------*/
+
+DSTATUS disk_initialize (void) {
+    BYTE n, cmd, ty, ocr[4];
+    WORD tmr;
+
+    DESELECT();
+    device.format(8);
+    device.frequency(SPI_FREQ);
+
+#if _WRITE_FUNC
+    if (MMC_SEL) disk_writep(0, 0);        /* Finalize write process if it is in progress */
+#endif
+    for (n = 100; n; n--) rcv_spi();    /* Dummy clocks */
+
+    ty = 0;
+    if (send_cmd(CMD0, 0) == 1) {            /* Enter Idle state */
+        if (send_cmd(CMD8, 0x1AA) == 1) {    /* SDv2 */
+            for (n = 0; n < 4; n++) ocr[n] = rcv_spi();        /* Get trailing return value of R7 resp */
+            if (ocr[2] == 0x01 && ocr[3] == 0xAA) {                /* The card can work at vdd range of 2.7-3.6V */
+                for (tmr = 12000; tmr && send_cmd(ACMD41, 1UL << 30); tmr--) ;    /* Wait for leaving idle state (ACMD41 with HCS bit) */
+                if (tmr && send_cmd(CMD58, 0) == 0) {        /* Check CCS bit in the OCR */
+                    for (n = 0; n < 4; n++) ocr[n] = rcv_spi();
+                    ty = (ocr[0] & 0x40) ? CT_SD2 | CT_BLOCK : CT_SD2;    /* SDv2 (HC or SC) */
+                }
+            }
+        } else {                            /* SDv1 or MMCv3 */
+            if (send_cmd(ACMD41, 0) <= 1)     {
+                ty = CT_SD1;
+                cmd = ACMD41;    /* SDv1 */
+            } else {
+                ty = CT_MMC;
+                cmd = CMD1;    /* MMCv3 */
+            }
+            for (tmr = 25000; tmr && send_cmd(cmd, 0); tmr--) ;    /* Wait for leaving idle state */
+            if (!tmr || send_cmd(CMD16, 512) != 0)            /* Set R/W block length to 512 */
+                ty = 0;
+        }
+    }
+    CardType = ty;
+    release_spi();
+
+    return ty ? 0 : STA_NOINIT;
+}
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Read partial sector                                                   */
+/*-----------------------------------------------------------------------*/
+
+DRESULT disk_readp (
+    BYTE *buff,        /* Pointer to the read buffer (NULL:Read bytes are forwarded to the stream) */
+    DWORD lba,        /* Sector number (LBA) */
+    WORD ofs,        /* Byte offset to read from (0..511) */
+    WORD cnt        /* Number of bytes to read (ofs + cnt mus be <= 512) */
+) {
+    DRESULT res;
+    BYTE rc;
+    WORD bc;
+
+
+    if (!(CardType & CT_BLOCK)) lba *= 512;        /* Convert to byte address if needed */
+
+    res = RES_ERROR;
+    if (send_cmd(CMD17, lba) == 0) {        /* READ_SINGLE_BLOCK */
+
+        bc = 30000;
+        do {                            /* Wait for data packet in timeout of 100ms */
+            rc = rcv_spi();
+        } while (rc == 0xFF && --bc);
+
+        if (rc == 0xFE) {                /* A data packet arrived */
+            bc = 514 - ofs - cnt;
+
+            /* Skip leading bytes */
+            if (ofs) {
+                do {
+                    rcv_spi();
+                } while (--ofs);
+            }
+
+            /* Receive a part of the sector */
+            if (buff) {    /* Store data to the memory */
+                do {
+                    *buff++ = rcv_spi();
+                } while (--cnt);
+            } else {    /* Forward data to the outgoing stream (depends on the project) */
+                do {
+                    rcv_spi();
+                } while (--cnt);
+            }
+
+            /* Skip trailing bytes and CRC */
+            do rcv_spi();
+            while (--bc);
+
+            res = RES_OK;
+        }
+    }
+
+    release_spi();
+
+    return res;
+}
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Write partial sector                                                  */
+/*-----------------------------------------------------------------------*/
+#if _WRITE_FUNC
+
+DRESULT disk_writep (
+    const BYTE *buff,    /* Pointer to the bytes to be written (NULL:Initiate/Finalize sector write) */
+    DWORD sa            /* Number of bytes to send, Sector number (LBA) or zero */
+) {
+    DRESULT res;
+    WORD bc;
+    static WORD wc;
+
+
+    res = RES_ERROR;
+
+    if (buff) {        /* Send data bytes */
+        bc = (WORD)sa;
+        while (bc && wc) {        /* Send data bytes to the card */
+            xmit_spi(*buff++);
+            wc--;
+            bc--;
+        }
+        res = RES_OK;
+    } else {
+        if (sa) {    /* Initiate sector write process */
+            if (!(CardType & CT_BLOCK)) sa *= 512;    /* Convert to byte address if needed */
+            if (send_cmd(CMD24, sa) == 0) {            /* WRITE_SINGLE_BLOCK */
+                xmit_spi(0xFF);
+                xmit_spi(0xFE);        /* Data block header */
+                wc = 512;                            /* Set byte counter */
+                res = RES_OK;
+            }
+        } else {    /* Finalize sector write process */
+            bc = wc + 2;
+            while (bc--) xmit_spi(0);    /* Fill left bytes and CRC with zeros */
+            if ((rcv_spi() & 0x1F) == 0x05) {    /* Receive data resp and wait for end of write process in timeout of 300ms */
+                for (bc = 65000; rcv_spi() != 0xFF && bc; bc--) ;    /* Wait ready */
+                if (bc) res = RES_OK;
+            }
+            release_spi();
+        }
+    }
+
+    return res;
+}
+#endif