aboutsummaryrefslogtreecommitdiffstats
path: root/tools/mpc86x_clk.c
blob: 8dfbd4e3d0cbf74fd8201120fd6348051acf74ec (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
/*
 * (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.
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */


#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;
}