/* * (C) Copyright 2003 Intracom S.A. * Pantelis Antoniou <panto@intracom.gr> * * This little program makes an exhaustive search for the * correct terms of pdf, mfi, mfn, mfd, s, dbrmo, in PLPRCR. * The goal is to produce a gclk2 from a xin input, while respecting * all the restrictions on their combination. * * Generaly you select the first row of the produced table. * * SPDX-License-Identifier: GPL-2.0+ */ #include <stdio.h> #include <stdlib.h> #define DPREF_MIN 10000000 #define DPREF_MAX 32000000 #define DPGDCK_MAX 320000000 #define DPGDCK_MIN 160000000 #define S_MIN 0 #define S_MAX 2 #define MFI_MIN 5 #define MFI_MAX 15 #define MFN_MIN 0 #define MFN_MAX 15 #define MFD_MIN 0 #define MFD_MAX 31 #define MF_MIN 5 #define MF_MAX 15 #define PDF_MIN 0 #define PDF_MAX 15 #define GCLK2_MAX 150000000 static int calculate (int xin, int target_clock, int ppm, int pdf, int mfi, int mfn, int mfd, int s, int *dprefp, int *dpgdckp, int *jdbckp, int *gclk2p, int *dbrmop) { unsigned int dpref, dpgdck, jdbck, gclk2, t1, t2, dbrmo; /* valid MFI? */ if (mfi < MFI_MIN) return -1; /* valid num, denum? */ if (mfn > 0 && mfn >= mfd) return -1; dpref = xin / (pdf + 1); /* valid dpef? */ if (dpref < DPREF_MIN || dpref > DPREF_MAX) return -1; if (mfn == 0) { dpgdck = (2 * mfi * xin) / (pdf + 1) ; dbrmo = 0; } else { /* 5 <= mfi + (mfn / mfd + 1) <= 15 */ t1 = mfd + 1; t2 = mfi * t1 + mfn; if ( MF_MIN * t1 > t2 || MF_MAX * t1 < t2) return -1; dpgdck = (unsigned int)(2 * (mfi * mfd + mfi + mfn) * (unsigned int)xin) / ((mfd + 1) * (pdf + 1)); dbrmo = 10 * mfn < (mfd + 1); } /* valid dpgclk? */ if (dpgdck < DPGDCK_MIN || dpgdck > DPGDCK_MAX) return -1; jdbck = dpgdck >> s; gclk2 = jdbck / 2; /* valid gclk2 */ if (gclk2 > GCLK2_MAX) return -1; t1 = abs(gclk2 - target_clock); /* XXX max 1MHz dev. in clock */ if (t1 > 1000000) return -1; /* dev within range (XXX gclk2 scaled to avoid overflow) */ if (t1 * 1000 > (unsigned int)ppm * (gclk2 / 1000)) return -1; *dprefp = dpref; *dpgdckp = dpgdck; *jdbckp = jdbck; *gclk2p = gclk2; *dbrmop = dbrmo; return gclk2; } int conf_clock(int xin, int target_clock, int ppm) { int pdf, s, mfn, mfd, mfi; int dpref, dpgdck, jdbck, gclk2, xout, dbrmo; int found = 0; /* integer multipliers */ for (pdf = PDF_MIN; pdf <= PDF_MAX; pdf++) { for (mfi = MFI_MIN; mfi <= MFI_MAX; mfi++) { for (s = 0; s <= S_MAX; s++) { xout = calculate(xin, target_clock, ppm, pdf, mfi, 0, 0, s, &dpref, &dpgdck, &jdbck, &gclk2, &dbrmo); if (xout < 0) continue; if (found == 0) { printf("pdf mfi mfn mfd s dbrmo dpref dpgdck jdbck gclk2 exact?\n"); printf("--- --- --- --- - ----- ----- ------ ----- ----- ------\n"); } printf("%3d %3d --- --- %1d %5d %9d %9d %9d %9d%s\n", pdf, mfi, s, dbrmo, dpref, dpgdck, jdbck, gclk2, gclk2 == target_clock ? " YES" : ""); found++; } } } /* fractional multipliers */ for (pdf = PDF_MIN; pdf <= PDF_MAX; pdf++) { for (mfi = MFI_MIN; mfi <= MFI_MAX; mfi++) { for (mfn = 1; mfn <= MFN_MAX; mfn++) { for (mfd = 1; mfd <= MFD_MAX; mfd++) { for (s = 0; s <= S_MAX; s++) { xout = calculate(xin, target_clock, ppm, pdf, mfi, mfn, mfd, s, &dpref, &dpgdck, &jdbck, &gclk2, &dbrmo); if (xout < 0) continue; if (found == 0) { printf("pdf mfi mfn mfd s dbrmo dpref dpgdck jdbck gclk2 exact?\n"); printf("--- --- --- --- - ----- ----- ------ ----- ----- ------\n"); } printf("%3d %3d %3d %3d %1d %5d %9d %9d %9d %9d%s\n", pdf, mfi, mfn, mfd, s, dbrmo, dpref, dpgdck, jdbck, gclk2, gclk2 == target_clock ? " YES" : ""); found++; } } } } } return found; } int main(int argc, char *argv[]) { int xin, want_gclk2, found, ppm = 100; if (argc < 3) { fprintf(stderr, "usage: mpc86x_clk <xin> <want_gclk2> [ppm]\n"); fprintf(stderr, " default ppm is 100\n"); return 10; } xin = atoi(argv[1]); want_gclk2 = atoi(argv[2]); if (argc >= 4) ppm = atoi(argv[3]); found = conf_clock(xin, want_gclk2, ppm); if (found <= 0) { fprintf(stderr, "cannot produce gclk2 %d from xin %d\n", want_gclk2, xin); return EXIT_FAILURE; } return EXIT_SUCCESS; }