Commit | Line | Data |
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bbc6fac3 SW |
1 | /* |
2 | * MPC8xx 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 "mpc8xx.h" | |
17 | #include "stdio.h" | |
18 | #include "io.h" | |
19 | ||
20 | #define MPC8XX_PLPRCR (0x284/4) /* PLL and Reset Control Register */ | |
21 | ||
22 | /* Return system clock from crystal frequency */ | |
23 | u32 mpc885_get_clock(u32 crystal) | |
24 | { | |
25 | u32 *immr; | |
26 | u32 plprcr; | |
27 | int mfi, mfn, mfd, pdf, div; | |
28 | u32 ret; | |
29 | ||
30 | immr = fsl_get_immr(); | |
31 | if (!immr) { | |
32 | printf("mpc885_get_clock: Couldn't get IMMR base.\r\n"); | |
33 | return 0; | |
34 | } | |
35 | ||
36 | plprcr = in_be32(&immr[MPC8XX_PLPRCR]); | |
37 | ||
38 | mfi = (plprcr >> 16) & 15; | |
39 | if (mfi < 5) { | |
40 | printf("Warning: PLPRCR[MFI] value of %d out-of-bounds\r\n", | |
41 | mfi); | |
42 | mfi = 5; | |
43 | } | |
44 | ||
45 | pdf = (plprcr >> 1) & 0xf; | |
46 | div = (plprcr >> 20) & 3; | |
47 | mfd = (plprcr >> 22) & 0x1f; | |
48 | mfn = (plprcr >> 27) & 0x1f; | |
49 | ||
50 | ret = crystal * mfi; | |
51 | ||
52 | if (mfn != 0) | |
53 | ret += crystal * mfn / (mfd + 1); | |
54 | ||
55 | return ret / (pdf + 1); | |
56 | } | |
57 | ||
58 | /* Set common device tree fields based on the given clock frequencies. */ | |
59 | void mpc8xx_set_clocks(u32 sysclk) | |
60 | { | |
61 | void *node; | |
62 | ||
63 | dt_fixup_cpu_clocks(sysclk, sysclk / 16, sysclk); | |
64 | ||
65 | node = finddevice("/soc/cpm"); | |
66 | if (node) | |
67 | setprop(node, "clock-frequency", &sysclk, 4); | |
68 | ||
69 | node = finddevice("/soc/cpm/brg"); | |
70 | if (node) | |
71 | setprop(node, "clock-frequency", &sysclk, 4); | |
72 | } | |
73 | ||
74 | int mpc885_fixup_clocks(u32 crystal) | |
75 | { | |
76 | u32 sysclk = mpc885_get_clock(crystal); | |
77 | if (!sysclk) | |
78 | return 0; | |
79 | ||
80 | mpc8xx_set_clocks(sysclk); | |
81 | return 1; | |
82 | } |