omap: Improve PLL parameter calculation tool

Improve the tool that finds multiplier and divider for PLLs:
The previous algorithm could get stuck on local maxima
and required the user to specify the tolerance. Improve
the algorithm to go through the entire search space and find
the optimal solution.

Signed-off-by: Aneesh V <aneesh@ti.com>

tools/omap/clocks_get_m_n.c

@@ -63,45 +63,41 @@ typedef unsigned int u32;
  *	$ gcc clocks_get_m_n.c
  *	$ ./a.out
  */
-int get_m_n_optimized(u32 target_freq_khz, u32 ref_freq_khz, u32 *m, u32 *n,
-			u32 tolerance_khz)
+int get_m_n_optimized(u32 target_freq_khz, u32 ref_freq_khz, u32 *M, u32 *N)
 {
-	u32 min_freq = target_freq_khz - tolerance_khz;
-	u32 max_freq = target_freq_khz;
-	u32 freq, freq_old;
-	*n = 1;
+	u32 freq = target_freq_khz;
+	u32 m_optimal, n_optimal, freq_optimal = 0, freq_old;
+	u32 m, n;
+	n = 1;
 	while (1) {
-		*m = min_freq / ref_freq_khz / 2 * (*n) ;
+		m = target_freq_khz / ref_freq_khz / 2 * n;
 		freq_old = 0;
 		while (1) {
-			freq = ref_freq_khz * 2 * (*m) / (*n);
-			if (abs(target_freq_khz - freq_old) <=
-				abs(target_freq_khz - freq)) {
+			freq = ref_freq_khz * 2 * m / n;
+			if (freq > target_freq_khz) {
 				freq = freq_old;
-				(*m)--;
+				m--;
 				break;
 			}
-			(*m)++;
+			m++;
 			freq_old = freq;
 		}
-		if (freq >= min_freq && freq <= max_freq)
+		if (freq > freq_optimal) {
+			freq_optimal = freq;
+			m_optimal = m;
+			n_optimal = n;
+		}
+		n++;
+		if ((freq_optimal == target_freq_khz) ||
+			((ref_freq_khz / n) < 1000)) {
 			break;
-		(*n)++;
-		if ((*n) > MAX_N + 1) {
-			printf("ref %d m %d n %d target %d : ",
-				ref_freq_khz, *m, *n, target_freq_khz);
-			printf("can not find m & n - please consider"
-				" increasing tolerance\n");
-			return -1;
 		}
 	}
-	(*n)--;
-	printf("ref %d m %d n %d target %d locked %d\n",
-		ref_freq_khz, *m, *n, target_freq_khz, freq);
-	if ((ref_freq_khz / (*n + 1)) < 1000) {
-		printf("\tREFCLK - CLKINP/(N+1) is less than 1 MHz - less than"
-			" ideal, locking time will be high!\n");
-	}
+	n--;
+	*M = m_optimal;
+	*N = n_optimal - 1;
+	printf("ref %d m %d n %d target %d locked %d\n", ref_freq_khz,
+		m_optimal, n_optimal - 1, target_freq_khz, freq_optimal);
 	return 0;
 }
 
@@ -109,89 +105,98 @@ void main(void)
 {
 	u32 m, n;
 	printf("\nMPU - 2000000\n");
-	get_m_n_optimized(2000000, 12000, &m, &n, 0);
-	get_m_n_optimized(2000000, 13000, &m, &n, 0);
-	get_m_n_optimized(2000000, 16800, &m, &n, 800);
-	get_m_n_optimized(2000000, 19200, &m, &n, 0);
-	get_m_n_optimized(2000000, 26000, &m, &n, 0);
-	get_m_n_optimized(2000000, 27000, &m, &n, 0);
-	get_m_n_optimized(2000000, 38400, &m, &n, 0);
+	get_m_n_optimized(2000000, 12000, &m, &n);
+	get_m_n_optimized(2000000, 13000, &m, &n);
+	get_m_n_optimized(2000000, 16800, &m, &n);
+	get_m_n_optimized(2000000, 19200, &m, &n);
+	get_m_n_optimized(2000000, 26000, &m, &n);
+	get_m_n_optimized(2000000, 27000, &m, &n);
+	get_m_n_optimized(2000000, 38400, &m, &n);
 
 	printf("\nMPU - 1200000\n");
-	get_m_n_optimized(1200000, 12000, &m, &n, 0);
-	get_m_n_optimized(1200000, 13000, &m, &n, 0);
-	get_m_n_optimized(1200000, 16800, &m, &n, 800);
-	get_m_n_optimized(1200000, 19200, &m, &n, 0);
-	get_m_n_optimized(1200000, 26000, &m, &n, 0);
-	get_m_n_optimized(1200000, 27000, &m, &n, 0);
-	get_m_n_optimized(1200000, 38400, &m, &n, 0);
+	get_m_n_optimized(1200000, 12000, &m, &n);
+	get_m_n_optimized(1200000, 13000, &m, &n);
+	get_m_n_optimized(1200000, 16800, &m, &n);
+	get_m_n_optimized(1200000, 19200, &m, &n);
+	get_m_n_optimized(1200000, 26000, &m, &n);
+	get_m_n_optimized(1200000, 27000, &m, &n);
+	get_m_n_optimized(1200000, 38400, &m, &n);
 
 	printf("\nMPU - 1584000\n");
-	get_m_n_optimized(1584000, 12000, &m, &n, 0);
-	get_m_n_optimized(1584000, 13000, &m, &n, 0);
-	get_m_n_optimized(1584000, 16800, &m, &n, 400);
-	get_m_n_optimized(1584000, 19200, &m, &n, 0);
-	get_m_n_optimized(1584000, 26000, &m, &n, 0);
-	get_m_n_optimized(1584000, 27000, &m, &n, 0);
-	get_m_n_optimized(1584000, 38400, &m, &n, 0);
+	get_m_n_optimized(1584000, 12000, &m, &n);
+	get_m_n_optimized(1584000, 13000, &m, &n);
+	get_m_n_optimized(1584000, 16800, &m, &n);
+	get_m_n_optimized(1584000, 19200, &m, &n);
+	get_m_n_optimized(1584000, 26000, &m, &n);
+	get_m_n_optimized(1584000, 27000, &m, &n);
+	get_m_n_optimized(1584000, 38400, &m, &n);
 
 	printf("\nCore 1600000\n");
-	get_m_n_optimized(1600000, 12000, &m, &n, 0);
-	get_m_n_optimized(1600000, 13000, &m, &n, 0);
-	get_m_n_optimized(1600000, 16800, &m, &n, 200);
-	get_m_n_optimized(1600000, 19200, &m, &n, 0);
-	get_m_n_optimized(1600000, 26000, &m, &n, 0);
-	get_m_n_optimized(1600000, 27000, &m, &n, 0);
-	get_m_n_optimized(1600000, 38400, &m, &n, 0);
+	get_m_n_optimized(1600000, 12000, &m, &n);
+	get_m_n_optimized(1600000, 13000, &m, &n);
+	get_m_n_optimized(1600000, 16800, &m, &n);
+	get_m_n_optimized(1600000, 19200, &m, &n);
+	get_m_n_optimized(1600000, 26000, &m, &n);
+	get_m_n_optimized(1600000, 27000, &m, &n);
+	get_m_n_optimized(1600000, 38400, &m, &n);
 
 	printf("\nPER 1536000\n");
-	get_m_n_optimized(1536000, 12000, &m, &n, 0);
-	get_m_n_optimized(1536000, 13000, &m, &n, 0);
-	get_m_n_optimized(1536000, 16800, &m, &n, 0);
-	get_m_n_optimized(1536000, 19200, &m, &n, 0);
-	get_m_n_optimized(1536000, 26000, &m, &n, 0);
-	get_m_n_optimized(1536000, 27000, &m, &n, 0);
-	get_m_n_optimized(1536000, 38400, &m, &n, 0);
+	get_m_n_optimized(1536000, 12000, &m, &n);
+	get_m_n_optimized(1536000, 13000, &m, &n);
+	get_m_n_optimized(1536000, 16800, &m, &n);
+	get_m_n_optimized(1536000, 19200, &m, &n);
+	get_m_n_optimized(1536000, 26000, &m, &n);
+	get_m_n_optimized(1536000, 27000, &m, &n);
+	get_m_n_optimized(1536000, 38400, &m, &n);
 
 	printf("\nIVA 1862000\n");
-	get_m_n_optimized(1862000, 12000, &m, &n, 0);
-	get_m_n_optimized(1862000, 13000, &m, &n, 0);
-	get_m_n_optimized(1862000, 16800, &m, &n, 0);
-	get_m_n_optimized(1862000, 19200, &m, &n, 900);
-	get_m_n_optimized(1862000, 26000, &m, &n, 0);
-	get_m_n_optimized(1862000, 27000, &m, &n, 0);
-	get_m_n_optimized(1862000, 38400, &m, &n, 800);
+	get_m_n_optimized(1862000, 12000, &m, &n);
+	get_m_n_optimized(1862000, 13000, &m, &n);
+	get_m_n_optimized(1862000, 16800, &m, &n);
+	get_m_n_optimized(1862000, 19200, &m, &n);
+	get_m_n_optimized(1862000, 26000, &m, &n);
+	get_m_n_optimized(1862000, 27000, &m, &n);
+	get_m_n_optimized(1862000, 38400, &m, &n);
+
+	printf("\nIVA Nitro - 1290000\n");
+	get_m_n_optimized(1290000, 12000, &m, &n);
+	get_m_n_optimized(1290000, 13000, &m, &n);
+	get_m_n_optimized(1290000, 16800, &m, &n);
+	get_m_n_optimized(1290000, 19200, &m, &n);
+	get_m_n_optimized(1290000, 26000, &m, &n);
+	get_m_n_optimized(1290000, 27000, &m, &n);
+	get_m_n_optimized(1290000, 38400, &m, &n);
 
 	printf("\nABE 196608 sys clk\n");
-	get_m_n_optimized(196608, 12000, &m, &n, 700);
-	get_m_n_optimized(196608, 13000, &m, &n, 200);
-	get_m_n_optimized(196608, 16800, &m, &n, 700);
-	get_m_n_optimized(196608, 19200, &m, &n, 400);
-	get_m_n_optimized(196608, 26000, &m, &n, 200);
-	get_m_n_optimized(196608, 27000, &m, &n, 900);
-	get_m_n_optimized(196608, 38400, &m, &n, 0);
+	get_m_n_optimized(196608, 12000, &m, &n);
+	get_m_n_optimized(196608, 13000, &m, &n);
+	get_m_n_optimized(196608, 16800, &m, &n);
+	get_m_n_optimized(196608, 19200, &m, &n);
+	get_m_n_optimized(196608, 26000, &m, &n);
+	get_m_n_optimized(196608, 27000, &m, &n);
+	get_m_n_optimized(196608, 38400, &m, &n);
 
 	printf("\nABE 196608 32K\n");
-	get_m_n_optimized(196608000/4, 32768, &m, &n, 0);
+	get_m_n_optimized(196608000/4, 32768, &m, &n);
 
 	printf("\nUSB 1920000\n");
-	get_m_n_optimized(1920000, 12000, &m, &n, 0);
-	get_m_n_optimized(1920000, 13000, &m, &n, 0);
-	get_m_n_optimized(1920000, 16800, &m, &n, 0);
-	get_m_n_optimized(1920000, 19200, &m, &n, 0);
-	get_m_n_optimized(1920000, 26000, &m, &n, 0);
-	get_m_n_optimized(1920000, 27000, &m, &n, 0);
-	get_m_n_optimized(1920000, 38400, &m, &n, 0);
+	get_m_n_optimized(1920000, 12000, &m, &n);
+	get_m_n_optimized(1920000, 13000, &m, &n);
+	get_m_n_optimized(1920000, 16800, &m, &n);
+	get_m_n_optimized(1920000, 19200, &m, &n);
+	get_m_n_optimized(1920000, 26000, &m, &n);
+	get_m_n_optimized(1920000, 27000, &m, &n);
+	get_m_n_optimized(1920000, 38400, &m, &n);
 
 	printf("\nCore ES1 1523712\n");
-	get_m_n_optimized(1524000, 12000, &m, &n, 100);
-	get_m_n_optimized(1524000, 13000, &m, &n, 0);
-	get_m_n_optimized(1524000, 16800, &m, &n, 0);
-	get_m_n_optimized(1524000, 19200, &m, &n, 0);
-	get_m_n_optimized(1524000, 26000, &m, &n, 0);
-	get_m_n_optimized(1524000, 27000, &m, &n, 0);
+	get_m_n_optimized(1524000, 12000, &m, &n);
+	get_m_n_optimized(1524000, 13000, &m, &n);
+	get_m_n_optimized(1524000, 16800, &m, &n);
+	get_m_n_optimized(1524000, 19200, &m, &n);
+	get_m_n_optimized(1524000, 26000, &m, &n);
+	get_m_n_optimized(1524000, 27000, &m, &n);
 
 	/* exact recommendation for SDPs */
-	get_m_n_optimized(1523712, 38400, &m, &n, 0);
+	get_m_n_optimized(1523712, 38400, &m, &n);
 
 }