Diff: main.cpp

Revision:

2:aea18e9b89d8

Parent:

1:1843a53b51a8

Child:

3:d4bb1e13a897

--- a/main.cpp	Sat Jun 06 09:58:13 2015 +0000
+++ b/main.cpp	Sat Jun 06 11:07:06 2015 +0000
@@ -16,9 +16,16 @@
 int initialise_card();
 int initialise_card_v1();
 int initialise_card_v2();
+int disk_initialize();
+uint64_t sd_sectors();
+uint64_t sectors;
+
 int cmd(int, int);
 int cmd58();
+int cmdx(int, int);
 int cmd8();
+int read(uint8_t*, uint32_t );
+static uint32_t ext_bits(unsigned char *, int , int );
 
 int cdv;
 
@@ -39,7 +46,8 @@
     while(1)
     { initialise_card();
       int result= initialise_card();
-      printf("%d\n",result);
+      printf("initialise card result=%d\n",result);
+      disk_initialize();
       wait(5);
     }
 }
@@ -64,11 +72,13 @@
  // send CMD8 to determine whther it is ver 2.x
     int r = cmd8();
     if (r == R1_IDLE_STATE) {
+        printf("Entering v2 bro\n");
         return initialise_card_v2();
-        printf("Entering v2 bro");
+        
     } else if (r == (R1_IDLE_STATE | R1_ILLEGAL_COMMAND)) {
+        printf("Entering v1 bro\n");
         return initialise_card_v1();
-        printf("Entering v1 bro");
+        
     } else {
         debug("Not in idle state after sending CMD8 (not an SD card?)\n");
         return SDCARD_FAIL;
@@ -195,4 +205,133 @@
     cs = 1;
     spi.write(0xFF);
     return -1; // timeout
-}
\ No newline at end of file
+}
+
+uint64_t sd_sectors() {
+    uint32_t c_size, c_size_mult, read_bl_len;
+    uint32_t block_len, mult, blocknr, capacity;
+    uint32_t hc_c_size;
+    uint64_t blocks;
+    
+    // CMD9, Response R2 (R1 byte + 16-byte block read)
+    if (cmdx(9, 0) != 0) {
+        debug("Didn't get a response from the disk\n");
+        return 0;
+    }
+    
+    uint8_t csd[16];
+    if (read(csd, 16) != 0) {
+        debug("Couldn't read csd response from disk\n");
+        return 0;
+    }
+    
+    // csd_structure : csd[127:126]
+    // c_size        : csd[73:62]
+    // c_size_mult   : csd[49:47]
+    // read_bl_len   : csd[83:80] - the *maximum* read block length
+    
+    int csd_structure = ext_bits(csd, 127, 126);
+    
+    switch (csd_structure) {
+        case 0:
+            cdv = 512;
+            c_size = ext_bits(csd, 73, 62);
+            c_size_mult = ext_bits(csd, 49, 47);
+            read_bl_len = ext_bits(csd, 83, 80);
+            
+            block_len = 1 << read_bl_len;
+            mult = 1 << (c_size_mult + 2);
+            blocknr = (c_size + 1) * mult;
+            capacity = blocknr * block_len;
+            blocks = capacity / 512;
+            debug_if(SD_DBG, "\n\rSDCard\n\rc_size: %d \n\rcapacity: %ld \n\rsectors: %lld\n\r", c_size, capacity, blocks);
+            break;
+        
+        case 1:
+            cdv = 1;
+            hc_c_size = ext_bits(csd, 63, 48);
+            blocks = (hc_c_size+1)*1024;
+            debug_if(SD_DBG, "\n\rSDHC Card \n\rhc_c_size: %d\n\rcapacity: %lld \n\rsectors: %lld\n\r", hc_c_size, blocks*512, blocks);
+            break;
+        
+        default:
+            debug("CSD struct unsupported\r\n");
+            return 0;
+    };
+    return blocks;
+}
+
+int cmdx(int cmd, int arg) {
+    cs = 0;
+    
+    // send a command
+    spi.write(0x40 | cmd);
+    spi.write(arg >> 24);
+    spi.write(arg >> 16);
+    spi.write(arg >> 8);
+    spi.write(arg >> 0);
+    spi.write(0x95);
+    
+    // wait for the repsonse (response[7] == 0)
+    for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) {
+        int response = spi.write(0xFF);
+        if (!(response & 0x80)) {
+            return response;
+        }
+    }
+    cs = 1;
+    spi.write(0xFF);
+    return -1; // timeout
+}
+
+
+int read(uint8_t *buffer, uint32_t length) {
+    cs = 0;
+    
+    // read until start byte (0xFF)
+    while (spi.write(0xFF) != 0xFE);
+    
+    // read data
+    for (int i = 0; i < length; i++) {
+        buffer[i] = spi.write(0xFF);
+    }
+    spi.write(0xFF); // checksum
+    spi.write(0xFF);
+    
+    cs = 1;
+    spi.write(0xFF);
+    return 0;
+}
+
+static uint32_t ext_bits(unsigned char *data, int msb, int lsb) {
+    uint32_t bits = 0;
+    uint32_t size = 1 + msb - lsb;
+    for (int i = 0; i < size; i++) {
+        uint32_t position = lsb + i;
+        uint32_t byte = 15 - (position >> 3);
+        uint32_t bit = position & 0x7;
+        uint32_t value = (data[byte] >> bit) & 1;
+        bits |= value << i;
+    }
+    return bits;
+}
+
+int disk_initialize() {
+    int i = initialise_card();
+    debug_if(SD_DBG, "init card = %d\n", i);
+    sectors = sd_sectors();
+    
+    // Set block length to 512 (CMD16)
+    if (cmd(16, 512) != 0) {
+        debug("Set 512-byte block timed out\n");
+        return 1;
+    }
+    else
+    {
+        printf("Hey,block init succesful");
+    }
+    
+    spi.frequency(1000000); // Set to 1MHz for data transfer
+    return 0;
+}
+