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  • only in /asuswrt-rt-n18u-9.0.0.4.380.2695/release/src-rt-6.x.4708/linux/linux-2.6.36/arch/powerpc/boot/
1/*
2 * PowerQUICC II support functions
3 *
4 * Author: Scott Wood <scottwood@freescale.com>
5 *
6 * Copyright (c) 2007 Freescale Semiconductor, Inc.
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License version 2 as published
10 * by the Free Software Foundation.
11 */
12
13#include "ops.h"
14#include "types.h"
15#include "fsl-soc.h"
16#include "pq2.h"
17#include "stdio.h"
18#include "io.h"
19
20#define PQ2_SCCR (0x10c80/4) /* System Clock Configuration Register */
21#define PQ2_SCMR (0x10c88/4) /* System Clock Mode Register */
22
23static int pq2_corecnf_map[] = {
24	3, 2, 2, 2, 4, 4, 5, 9, 6, 11, 8, 10, 3, 12, 7, -1,
25	6, 5, 13, 2, 14, 4, 15, 9, 0, 11, 8, 10, 16, 12, 7, -1
26};
27
28/* Get various clocks from crystal frequency.
29 * Returns zero on failure and non-zero on success.
30 */
31int pq2_get_clocks(u32 crystal, u32 *sysfreq, u32 *corefreq,
32                   u32 *timebase, u32 *brgfreq)
33{
34	u32 *immr;
35	u32 sccr, scmr, mainclk, busclk;
36	int corecnf, busdf, plldf, pllmf, dfbrg;
37
38	immr = fsl_get_immr();
39	if (!immr) {
40		printf("pq2_get_clocks: Couldn't get IMMR base.\r\n");
41		return 0;
42	}
43
44	sccr = in_be32(&immr[PQ2_SCCR]);
45	scmr = in_be32(&immr[PQ2_SCMR]);
46
47	dfbrg = sccr & 3;
48	corecnf = (scmr >> 24) & 0x1f;
49	busdf = (scmr >> 20) & 0xf;
50	plldf = (scmr >> 12) & 1;
51	pllmf = scmr & 0xfff;
52
53	mainclk = crystal * (pllmf + 1) / (plldf + 1);
54	busclk = mainclk / (busdf + 1);
55
56	if (sysfreq)
57		*sysfreq = mainclk / 2;
58	if (timebase)
59		*timebase = busclk / 4;
60	if (brgfreq)
61		*brgfreq = mainclk / (1 << ((dfbrg + 1) * 2));
62
63	if (corefreq) {
64		int coremult = pq2_corecnf_map[corecnf];
65
66		if (coremult < 0)
67			*corefreq = mainclk / 2;
68		else if (coremult == 0)
69			return 0;
70		else
71			*corefreq = busclk * coremult / 2;
72	}
73
74	return 1;
75}
76
77/* Set common device tree fields based on the given clock frequencies. */
78void pq2_set_clocks(u32 sysfreq, u32 corefreq, u32 timebase, u32 brgfreq)
79{
80	void *node;
81
82	dt_fixup_cpu_clocks(corefreq, timebase, sysfreq);
83
84	node = finddevice("/soc/cpm");
85	if (node)
86		setprop(node, "clock-frequency", &sysfreq, 4);
87
88	node = finddevice("/soc/cpm/brg");
89	if (node)
90		setprop(node, "clock-frequency", &brgfreq, 4);
91}
92
93int pq2_fixup_clocks(u32 crystal)
94{
95	u32 sysfreq, corefreq, timebase, brgfreq;
96
97	if (!pq2_get_clocks(crystal, &sysfreq, &corefreq, &timebase, &brgfreq))
98		return 0;
99
100	pq2_set_clocks(sysfreq, corefreq, timebase, brgfreq);
101	return 1;
102}
103