Reintroduced CRC7 calculation.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@3954 35acf78f-673a-0410-8e92-d51de3d6d3f4

1 files changed, 49 insertions, 6 deletions

diff --git a/os/hal/src/mmc_spi.c b/os/hal/src/mmc_spi.c
index 079dcf3c0..c7b3372f2 100644
--- a/os/hal/src/mmc_spi.c
+++ b/os/hal/src/mmc_spi.c
@@ -48,11 +48,54 @@
 /* Driver local variables.                                                   */

 /*===========================================================================*/

 

+/**

+ * @brief   Lookup table for CRC-7 ( based on polynomial x^7 + x^3 + 1).

+ */

+static const uint8_t crc7_lookup_table[256] = {

+  0x00, 0x09, 0x12, 0x1b, 0x24, 0x2d, 0x36, 0x3f, 0x48, 0x41, 0x5a, 0x53,

+  0x6c, 0x65, 0x7e, 0x77, 0x19, 0x10, 0x0b, 0x02, 0x3d, 0x34, 0x2f, 0x26,

+  0x51, 0x58, 0x43, 0x4a, 0x75, 0x7c, 0x67, 0x6e, 0x32, 0x3b, 0x20, 0x29,

+  0x16, 0x1f, 0x04, 0x0d, 0x7a, 0x73, 0x68, 0x61, 0x5e, 0x57, 0x4c, 0x45,

+  0x2b, 0x22, 0x39, 0x30, 0x0f, 0x06, 0x1d, 0x14, 0x63, 0x6a, 0x71, 0x78,

+  0x47, 0x4e, 0x55, 0x5c, 0x64, 0x6d, 0x76, 0x7f, 0x40, 0x49, 0x52, 0x5b,

+  0x2c, 0x25, 0x3e, 0x37, 0x08, 0x01, 0x1a, 0x13, 0x7d, 0x74, 0x6f, 0x66,

+  0x59, 0x50, 0x4b, 0x42, 0x35, 0x3c, 0x27, 0x2e, 0x11, 0x18, 0x03, 0x0a,

+  0x56, 0x5f, 0x44, 0x4d, 0x72, 0x7b, 0x60, 0x69, 0x1e, 0x17, 0x0c, 0x05,

+  0x3a, 0x33, 0x28, 0x21, 0x4f, 0x46, 0x5d, 0x54, 0x6b, 0x62, 0x79, 0x70,

+  0x07, 0x0e, 0x15, 0x1c, 0x23, 0x2a, 0x31, 0x38, 0x41, 0x48, 0x53, 0x5a,

+  0x65, 0x6c, 0x77, 0x7e, 0x09, 0x00, 0x1b, 0x12, 0x2d, 0x24, 0x3f, 0x36,

+  0x58, 0x51, 0x4a, 0x43, 0x7c, 0x75, 0x6e, 0x67, 0x10, 0x19, 0x02, 0x0b,

+  0x34, 0x3d, 0x26, 0x2f, 0x73, 0x7a, 0x61, 0x68, 0x57, 0x5e, 0x45, 0x4c,

+  0x3b, 0x32, 0x29, 0x20, 0x1f, 0x16, 0x0d, 0x04, 0x6a, 0x63, 0x78, 0x71,

+  0x4e, 0x47, 0x5c, 0x55, 0x22, 0x2b, 0x30, 0x39, 0x06, 0x0f, 0x14, 0x1d,

+  0x25, 0x2c, 0x37, 0x3e, 0x01, 0x08, 0x13, 0x1a, 0x6d, 0x64, 0x7f, 0x76,

+  0x49, 0x40, 0x5b, 0x52, 0x3c, 0x35, 0x2e, 0x27, 0x18, 0x11, 0x0a, 0x03,

+  0x74, 0x7d, 0x66, 0x6f, 0x50, 0x59, 0x42, 0x4b, 0x17, 0x1e, 0x05, 0x0c,

+  0x33, 0x3a, 0x21, 0x28, 0x5f, 0x56, 0x4d, 0x44, 0x7b, 0x72, 0x69, 0x60,

+  0x0e, 0x07, 0x1c, 0x15, 0x2a, 0x23, 0x38, 0x31, 0x46, 0x4f, 0x54, 0x5d,

+  0x62, 0x6b, 0x70, 0x79

+};

+

 /*===========================================================================*/

 /* Driver local functions.                                                   */

 /*===========================================================================*/

 

 /**

+ * @brief Calculate the MMC standard CRC-7 based on a lookup table.

+ *

+ * @param[in] crc       start value for CRC

+ * @param[in] buffer    pointer to data buffer

+ * @param[in] len       length of data

+ * @return              Calculated CRC

+ */

+static uint8_t crc7(uint8_t crc, const uint8_t *buffer, size_t len) {

+

+  while (len--)

+    crc = crc7_lookup_table[(crc << 1) ^ (*buffer++)];

+  return crc;

+}

+

+/**

  * @brief   Inserion monitor timer callback function.

  *

  * @param[in] p         pointer to the @p MMCDriver object

@@ -132,7 +175,9 @@ static void send_hdr(MMCDriver *mmcp, uint8_t cmd, uint32_t arg) {
   buf[2] = arg >> 16;

   buf[3] = arg >> 8;

   buf[4] = arg;

-  buf[5] = 0x95;        /* Valid for CMD0 ignored by other commands. */

+  /* Calculate CRC for command header, shift to right position, add stop bit.*/

+  buf[5] = ((crc7(0, buf, 5) & 0x7F) << 1) | 0x01;

+

   spiSend(mmcp->spip, 6, buf);

 }

 

@@ -665,8 +710,10 @@ bool_t mmcSequentialWrite(MMCDriver *mmcp, const uint8_t *buffer) {
   spiSend(mmcp->spip, MMC_SECTOR_SIZE, buffer);     /* Data.                */

   spiIgnore(mmcp->spip, 2);                         /* CRC ignored.         */

   spiReceive(mmcp->spip, 1, b);

-  if ((b[0] & 0x1F) == 0x05)

+  if ((b[0] & 0x1F) == 0x05) {

+    wait(mmcp);

     return FALSE;

+  }

 

   /* Error.*/

   spiUnselect(mmcp->spip);

@@ -699,10 +746,6 @@ bool_t mmcStopSequentialWrite(MMCDriver *mmcp) {
   }

   chSysUnlock();

 

-  /* Wait completion of the last write operation.*/

-  wait(mmcp);

-

-  /* Semd stop command.*/

   spiSend(mmcp->spip, sizeof(stop), stop);

   spiUnselect(mmcp->spip);