software/libbase/spisdcard: add USE_SPISDCARD_RECLOCKING define to easily disable reclocking.

litex/soc/software/libbase/spisdcard.c

@@ -21,6 +21,8 @@
 #include <time.h>
 #include <string.h>
 
+#define USE_SPISCARD_RECLOCKING
+
 #ifdef CSR_SPISDCARD_BASE
 // Import prototypes for the functions
 #include <spisdcard.h>
@@ -138,7 +140,7 @@ uint8_t spi_setspimode(void)
 {
     uint32_t r;
     int i, timeout=32;
-    
+
     // Initialise SPI mode
     // set CS to HIGH
     // Send pulses
@@ -444,6 +446,7 @@ uint8_t spi_sdcard_readMBR(void)
         return FAILURE;
     }
 
+#ifdef USE_SPISCARD_RECLOCKING
     // Reclock the card
     // Calculate 16MHz as an integer divider from the CONFIG_CLOCK_FREQUENCY
     // Add 1 as will be rounded down
@@ -454,7 +457,7 @@ uint8_t spi_sdcard_readMBR(void)
         divider=2;
     printf("Reclocking from %dKHz to %dKHz\n\n", CONFIG_CLOCK_FREQUENCY/(int)spisdcard_clk_divider_read()/1000, CONFIG_CLOCK_FREQUENCY/divider/1000);
     spisdcard_clk_divider_write(divider);
-    
+
     // Read in FAT16 File Allocation Table, array of 16bit unsinged integers
     // Calculate Storage from TOP of MAIN RAM
     sdCardFatTable = (uint16_t *)(MAIN_RAM_BASE+MAIN_RAM_SIZE-sdCardFatBootSector.sector_size*sdCardFatBootSector.fat_size_sectors);
@@ -468,6 +471,7 @@ uint8_t spi_sdcard_readMBR(void)
             return FAILURE;
         }
     }
+#endif
 
     // Read in FAT16 Root Directory
     // Calculate Storage from TOP of MAIN RAM