mpc86x_clk.c 5.1 KB

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  1. /*
  2. * (C) Copyright 2003 Intracom S.A.
  3. * Pantelis Antoniou <panto@intracom.gr>
  4. *
  5. * This little program makes an exhaustive search for the
  6. * correct terms of pdf, mfi, mfn, mfd, s, dbrmo, in PLPRCR.
  7. * The goal is to produce a gclk2 from a xin input, while respecting
  8. * all the restrictions on their combination.
  9. *
  10. * Generaly you select the first row of the produced table.
  11. *
  12. * See file CREDITS for list of people who contributed to this
  13. * project.
  14. *
  15. * This program is free software; you can redistribute it and/or
  16. * modify it under the terms of the GNU General Public License as
  17. * published by the Free Software Foundation; either version 2 of
  18. * the License, or (at your option) any later version.
  19. *
  20. * This program is distributed in the hope that it will be useful,
  21. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  22. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  23. * GNU General Public License for more details.
  24. *
  25. * You should have received a copy of the GNU General Public License
  26. * along with this program; if not, write to the Free Software
  27. * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  28. * MA 02111-1307 USA
  29. */
  30. #include <stdio.h>
  31. #include <stdlib.h>
  32. #define DPREF_MIN 10000000
  33. #define DPREF_MAX 32000000
  34. #define DPGDCK_MAX 320000000
  35. #define DPGDCK_MIN 160000000
  36. #define S_MIN 0
  37. #define S_MAX 2
  38. #define MFI_MIN 5
  39. #define MFI_MAX 15
  40. #define MFN_MIN 0
  41. #define MFN_MAX 15
  42. #define MFD_MIN 0
  43. #define MFD_MAX 31
  44. #define MF_MIN 5
  45. #define MF_MAX 15
  46. #define PDF_MIN 0
  47. #define PDF_MAX 15
  48. #define GCLK2_MAX 150000000
  49. static int calculate (int xin, int target_clock,
  50. int ppm, int pdf, int mfi, int mfn, int mfd, int s,
  51. int *dprefp, int *dpgdckp, int *jdbckp,
  52. int *gclk2p, int *dbrmop)
  53. {
  54. unsigned int dpref, dpgdck, jdbck, gclk2, t1, t2, dbrmo;
  55. /* valid MFI? */
  56. if (mfi < MFI_MIN)
  57. return -1;
  58. /* valid num, denum? */
  59. if (mfn > 0 && mfn >= mfd)
  60. return -1;
  61. dpref = xin / (pdf + 1);
  62. /* valid dpef? */
  63. if (dpref < DPREF_MIN || dpref > DPREF_MAX)
  64. return -1;
  65. if (mfn == 0) {
  66. dpgdck = (2 * mfi * xin) / (pdf + 1) ;
  67. dbrmo = 0;
  68. } else {
  69. /* 5 <= mfi + (mfn / mfd + 1) <= 15 */
  70. t1 = mfd + 1;
  71. t2 = mfi * t1 + mfn;
  72. if ( MF_MIN * t1 > t2 || MF_MAX * t1 < t2)
  73. return -1;
  74. dpgdck = (unsigned int)(2 * (mfi * mfd + mfi + mfn) *
  75. (unsigned int)xin) /
  76. ((mfd + 1) * (pdf + 1));
  77. dbrmo = 10 * mfn < (mfd + 1);
  78. }
  79. /* valid dpgclk? */
  80. if (dpgdck < DPGDCK_MIN || dpgdck > DPGDCK_MAX)
  81. return -1;
  82. jdbck = dpgdck >> s;
  83. gclk2 = jdbck / 2;
  84. /* valid gclk2 */
  85. if (gclk2 > GCLK2_MAX)
  86. return -1;
  87. t1 = abs(gclk2 - target_clock);
  88. /* XXX max 1MHz dev. in clock */
  89. if (t1 > 1000000)
  90. return -1;
  91. /* dev within range (XXX gclk2 scaled to avoid overflow) */
  92. if (t1 * 1000 > (unsigned int)ppm * (gclk2 / 1000))
  93. return -1;
  94. *dprefp = dpref;
  95. *dpgdckp = dpgdck;
  96. *jdbckp = jdbck;
  97. *gclk2p = gclk2;
  98. *dbrmop = dbrmo;
  99. return gclk2;
  100. }
  101. int conf_clock(int xin, int target_clock, int ppm)
  102. {
  103. int pdf, s, mfn, mfd, mfi;
  104. int dpref, dpgdck, jdbck, gclk2, xout, dbrmo;
  105. int found = 0;
  106. /* integer multipliers */
  107. for (pdf = PDF_MIN; pdf <= PDF_MAX; pdf++) {
  108. for (mfi = MFI_MIN; mfi <= MFI_MAX; mfi++) {
  109. for (s = 0; s <= S_MAX; s++) {
  110. xout = calculate(xin, target_clock,
  111. ppm, pdf, mfi, 0, 0, s,
  112. &dpref, &dpgdck, &jdbck,
  113. &gclk2, &dbrmo);
  114. if (xout < 0)
  115. continue;
  116. if (found == 0) {
  117. printf("pdf mfi mfn mfd s dbrmo dpref dpgdck jdbck gclk2 exact?\n");
  118. printf("--- --- --- --- - ----- ----- ------ ----- ----- ------\n");
  119. }
  120. printf("%3d %3d --- --- %1d %5d %9d %9d %9d %9d%s\n",
  121. pdf, mfi, s, dbrmo,
  122. dpref, dpgdck, jdbck, gclk2,
  123. gclk2 == target_clock ? " YES" : "");
  124. found++;
  125. }
  126. }
  127. }
  128. /* fractional multipliers */
  129. for (pdf = PDF_MIN; pdf <= PDF_MAX; pdf++) {
  130. for (mfi = MFI_MIN; mfi <= MFI_MAX; mfi++) {
  131. for (mfn = 1; mfn <= MFN_MAX; mfn++) {
  132. for (mfd = 1; mfd <= MFD_MAX; mfd++) {
  133. for (s = 0; s <= S_MAX; s++) {
  134. xout = calculate(xin, target_clock,
  135. ppm, pdf, mfi, mfn, mfd, s,
  136. &dpref, &dpgdck, &jdbck,
  137. &gclk2, &dbrmo);
  138. if (xout < 0)
  139. continue;
  140. if (found == 0) {
  141. printf("pdf mfi mfn mfd s dbrmo dpref dpgdck jdbck gclk2 exact?\n");
  142. printf("--- --- --- --- - ----- ----- ------ ----- ----- ------\n");
  143. }
  144. printf("%3d %3d %3d %3d %1d %5d %9d %9d %9d %9d%s\n",
  145. pdf, mfi, mfn, mfd, s,
  146. dbrmo, dpref, dpgdck, jdbck, gclk2,
  147. gclk2 == target_clock ? " YES" : "");
  148. found++;
  149. }
  150. }
  151. }
  152. }
  153. }
  154. return found;
  155. }
  156. int main(int argc, char *argv[])
  157. {
  158. int xin, want_gclk2, found, ppm = 100;
  159. if (argc < 3) {
  160. fprintf(stderr, "usage: mpc86x_clk <xin> <want_gclk2> [ppm]\n");
  161. fprintf(stderr, " default ppm is 100\n");
  162. return 10;
  163. }
  164. xin = atoi(argv[1]);
  165. want_gclk2 = atoi(argv[2]);
  166. if (argc >= 4)
  167. ppm = atoi(argv[3]);
  168. found = conf_clock(xin, want_gclk2, ppm);
  169. if (found <= 0) {
  170. fprintf(stderr, "cannot produce gclk2 %d from xin %d\n",
  171. want_gclk2, xin);
  172. return EXIT_FAILURE;
  173. }
  174. return EXIT_SUCCESS;
  175. }