+#define NUM_TRIES 64
+#define NUM_READS 10
+
+void sdram_tr1_set(int ram_address, int* tr1_value)
+{
+ int i;
+ int j, k;
+ volatile unsigned int* ram_pointer = (unsigned int*)ram_address;
+ int first_good = -1, last_bad = 0x1ff;
+
+ unsigned long test[NUM_TRIES] = {
+ 0x00000000, 0x00000000, 0xFFFFFFFF, 0xFFFFFFFF,
+ 0x00000000, 0x00000000, 0xFFFFFFFF, 0xFFFFFFFF,
+ 0xFFFFFFFF, 0xFFFFFFFF, 0x00000000, 0x00000000,
+ 0xFFFFFFFF, 0xFFFFFFFF, 0x00000000, 0x00000000,
+ 0xAAAAAAAA, 0xAAAAAAAA, 0x55555555, 0x55555555,
+ 0xAAAAAAAA, 0xAAAAAAAA, 0x55555555, 0x55555555,
+ 0x55555555, 0x55555555, 0xAAAAAAAA, 0xAAAAAAAA,
+ 0x55555555, 0x55555555, 0xAAAAAAAA, 0xAAAAAAAA,
+ 0xA5A5A5A5, 0xA5A5A5A5, 0x5A5A5A5A, 0x5A5A5A5A,
+ 0xA5A5A5A5, 0xA5A5A5A5, 0x5A5A5A5A, 0x5A5A5A5A,
+ 0x5A5A5A5A, 0x5A5A5A5A, 0xA5A5A5A5, 0xA5A5A5A5,
+ 0x5A5A5A5A, 0x5A5A5A5A, 0xA5A5A5A5, 0xA5A5A5A5,
+ 0xAA55AA55, 0xAA55AA55, 0x55AA55AA, 0x55AA55AA,
+ 0xAA55AA55, 0xAA55AA55, 0x55AA55AA, 0x55AA55AA,
+ 0x55AA55AA, 0x55AA55AA, 0xAA55AA55, 0xAA55AA55,
+ 0x55AA55AA, 0x55AA55AA, 0xAA55AA55, 0xAA55AA55 };
+
+ /* go through all possible SDRAM0_TR1[RDCT] values */
+ for (i=0; i<=0x1ff; i++) {
+ /* set the current value for TR1 */
+ mtsdram(mem_tr1, (0x80800800 | i));
+
+ /* write values */
+ for (j=0; j<NUM_TRIES; j++) {
+ ram_pointer[j] = test[j];
+
+ /* clear any cache at ram location */
+ __asm__("dcbf 0,%0": :"r" (&ram_pointer[j]));
+ }
+
+ /* read values back */
+ for (j=0; j<NUM_TRIES; j++) {
+ for (k=0; k<NUM_READS; k++) {
+ /* clear any cache at ram location */
+ __asm__("dcbf 0,%0": :"r" (&ram_pointer[j]));
+
+ if (ram_pointer[j] != test[j])
+ break;
+ }
+
+ /* read error */
+ if (k != NUM_READS) {
+ break;
+ }
+ }
+
+ /* we have a SDRAM0_TR1[RDCT] that is part of the window */
+ if (j == NUM_TRIES) {
+ if (first_good == -1)
+ first_good = i; /* found beginning of window */
+ } else { /* bad read */
+ /* if we have not had a good read then don't care */
+ if(first_good != -1) {
+ /* first failure after a good read */
+ last_bad = i-1;
+ break;
+ }
+ }
+ }
+
+ /* return the current value for TR1 */
+ *tr1_value = (first_good + last_bad) / 2;
+}
+