diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/arm/common/icst307.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/arm/common/icst307.c')
-rw-r--r-- | arch/arm/common/icst307.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/arch/arm/common/icst307.c b/arch/arm/common/icst307.c new file mode 100644 index 000000000000..bafe8b19be82 --- /dev/null +++ b/arch/arm/common/icst307.c | |||
@@ -0,0 +1,161 @@ | |||
1 | /* | ||
2 | * linux/arch/arm/common/icst307.c | ||
3 | * | ||
4 | * Copyright (C) 2003 Deep Blue Solutions, Ltd, All Rights Reserved. | ||
5 | * | ||
6 | * This program is free software; you can redistribute it and/or modify | ||
7 | * it under the terms of the GNU General Public License version 2 as | ||
8 | * published by the Free Software Foundation. | ||
9 | * | ||
10 | * Support functions for calculating clocks/divisors for the ICST307 | ||
11 | * clock generators. See http://www.icst.com/ for more information | ||
12 | * on these devices. | ||
13 | * | ||
14 | * This is an almost identical implementation to the ICST525 clock generator. | ||
15 | * The s2div and idx2s files are different | ||
16 | */ | ||
17 | #include <linux/module.h> | ||
18 | #include <linux/kernel.h> | ||
19 | |||
20 | #include <asm/hardware/icst307.h> | ||
21 | |||
22 | /* | ||
23 | * Divisors for each OD setting. | ||
24 | */ | ||
25 | static unsigned char s2div[8] = { 10, 2, 8, 4, 5, 7, 3, 6 }; | ||
26 | |||
27 | unsigned long icst307_khz(const struct icst307_params *p, struct icst307_vco vco) | ||
28 | { | ||
29 | return p->ref * 2 * (vco.v + 8) / ((vco.r + 2) * s2div[vco.s]); | ||
30 | } | ||
31 | |||
32 | EXPORT_SYMBOL(icst307_khz); | ||
33 | |||
34 | /* | ||
35 | * Ascending divisor S values. | ||
36 | */ | ||
37 | static unsigned char idx2s[8] = { 1, 6, 3, 4, 7, 5, 2, 0 }; | ||
38 | |||
39 | struct icst307_vco | ||
40 | icst307_khz_to_vco(const struct icst307_params *p, unsigned long freq) | ||
41 | { | ||
42 | struct icst307_vco vco = { .s = 1, .v = p->vd_max, .r = p->rd_max }; | ||
43 | unsigned long f; | ||
44 | unsigned int i = 0, rd, best = (unsigned int)-1; | ||
45 | |||
46 | /* | ||
47 | * First, find the PLL output divisor such | ||
48 | * that the PLL output is within spec. | ||
49 | */ | ||
50 | do { | ||
51 | f = freq * s2div[idx2s[i]]; | ||
52 | |||
53 | /* | ||
54 | * f must be between 6MHz and 200MHz (3.3 or 5V) | ||
55 | */ | ||
56 | if (f > 6000 && f <= p->vco_max) | ||
57 | break; | ||
58 | } while (i < ARRAY_SIZE(idx2s)); | ||
59 | |||
60 | if (i > ARRAY_SIZE(idx2s)) | ||
61 | return vco; | ||
62 | |||
63 | vco.s = idx2s[i]; | ||
64 | |||
65 | /* | ||
66 | * Now find the closest divisor combination | ||
67 | * which gives a PLL output of 'f'. | ||
68 | */ | ||
69 | for (rd = p->rd_min; rd <= p->rd_max; rd++) { | ||
70 | unsigned long fref_div, f_pll; | ||
71 | unsigned int vd; | ||
72 | int f_diff; | ||
73 | |||
74 | fref_div = (2 * p->ref) / rd; | ||
75 | |||
76 | vd = (f + fref_div / 2) / fref_div; | ||
77 | if (vd < p->vd_min || vd > p->vd_max) | ||
78 | continue; | ||
79 | |||
80 | f_pll = fref_div * vd; | ||
81 | f_diff = f_pll - f; | ||
82 | if (f_diff < 0) | ||
83 | f_diff = -f_diff; | ||
84 | |||
85 | if ((unsigned)f_diff < best) { | ||
86 | vco.v = vd - 8; | ||
87 | vco.r = rd - 2; | ||
88 | if (f_diff == 0) | ||
89 | break; | ||
90 | best = f_diff; | ||
91 | } | ||
92 | } | ||
93 | |||
94 | return vco; | ||
95 | } | ||
96 | |||
97 | EXPORT_SYMBOL(icst307_khz_to_vco); | ||
98 | |||
99 | struct icst307_vco | ||
100 | icst307_ps_to_vco(const struct icst307_params *p, unsigned long period) | ||
101 | { | ||
102 | struct icst307_vco vco = { .s = 1, .v = p->vd_max, .r = p->rd_max }; | ||
103 | unsigned long f, ps; | ||
104 | unsigned int i = 0, rd, best = (unsigned int)-1; | ||
105 | |||
106 | ps = 1000000000UL / p->vco_max; | ||
107 | |||
108 | /* | ||
109 | * First, find the PLL output divisor such | ||
110 | * that the PLL output is within spec. | ||
111 | */ | ||
112 | do { | ||
113 | f = period / s2div[idx2s[i]]; | ||
114 | |||
115 | /* | ||
116 | * f must be between 6MHz and 200MHz (3.3 or 5V) | ||
117 | */ | ||
118 | if (f >= ps && f < 1000000000UL / 6000 + 1) | ||
119 | break; | ||
120 | } while (i < ARRAY_SIZE(idx2s)); | ||
121 | |||
122 | if (i > ARRAY_SIZE(idx2s)) | ||
123 | return vco; | ||
124 | |||
125 | vco.s = idx2s[i]; | ||
126 | |||
127 | ps = 500000000UL / p->ref; | ||
128 | |||
129 | /* | ||
130 | * Now find the closest divisor combination | ||
131 | * which gives a PLL output of 'f'. | ||
132 | */ | ||
133 | for (rd = p->rd_min; rd <= p->rd_max; rd++) { | ||
134 | unsigned long f_in_div, f_pll; | ||
135 | unsigned int vd; | ||
136 | int f_diff; | ||
137 | |||
138 | f_in_div = ps * rd; | ||
139 | |||
140 | vd = (f_in_div + f / 2) / f; | ||
141 | if (vd < p->vd_min || vd > p->vd_max) | ||
142 | continue; | ||
143 | |||
144 | f_pll = (f_in_div + vd / 2) / vd; | ||
145 | f_diff = f_pll - f; | ||
146 | if (f_diff < 0) | ||
147 | f_diff = -f_diff; | ||
148 | |||
149 | if ((unsigned)f_diff < best) { | ||
150 | vco.v = vd - 8; | ||
151 | vco.r = rd - 2; | ||
152 | if (f_diff == 0) | ||
153 | break; | ||
154 | best = f_diff; | ||
155 | } | ||
156 | } | ||
157 | |||
158 | return vco; | ||
159 | } | ||
160 | |||
161 | EXPORT_SYMBOL(icst307_ps_to_vco); | ||