From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-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! --- arch/arm/common/icst525.c | 160 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 160 insertions(+) create mode 100644 arch/arm/common/icst525.c (limited to 'arch/arm/common/icst525.c') diff --git a/arch/arm/common/icst525.c b/arch/arm/common/icst525.c new file mode 100644 index 00000000000..943ef88c037 --- /dev/null +++ b/arch/arm/common/icst525.c @@ -0,0 +1,160 @@ +/* + * linux/arch/arm/common/icst525.c + * + * Copyright (C) 2003 Deep Blue Solutions, Ltd, All Rights Reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Support functions for calculating clocks/divisors for the ICST525 + * clock generators. See http://www.icst.com/ for more information + * on these devices. + */ +#include +#include + +#include + +/* + * Divisors for each OD setting. + */ +static unsigned char s2div[8] = { 10, 2, 8, 4, 5, 7, 9, 6 }; + +unsigned long icst525_khz(const struct icst525_params *p, struct icst525_vco vco) +{ + return p->ref * 2 * (vco.v + 8) / ((vco.r + 2) * s2div[vco.s]); +} + +EXPORT_SYMBOL(icst525_khz); + +/* + * Ascending divisor S values. + */ +static unsigned char idx2s[] = { 1, 3, 4, 7, 5, 2, 6, 0 }; + +struct icst525_vco +icst525_khz_to_vco(const struct icst525_params *p, unsigned long freq) +{ + struct icst525_vco vco = { .s = 1, .v = p->vd_max, .r = p->rd_max }; + unsigned long f; + unsigned int i = 0, rd, best = (unsigned int)-1; + + /* + * First, find the PLL output divisor such + * that the PLL output is within spec. + */ + do { + f = freq * s2div[idx2s[i]]; + + /* + * f must be between 10MHz and + * 320MHz (5V) or 200MHz (3V) + */ + if (f > 10000 && f <= p->vco_max) + break; + } while (i < ARRAY_SIZE(idx2s)); + + if (i > ARRAY_SIZE(idx2s)) + return vco; + + vco.s = idx2s[i]; + + /* + * Now find the closest divisor combination + * which gives a PLL output of 'f'. + */ + for (rd = p->rd_min; rd <= p->rd_max; rd++) { + unsigned long fref_div, f_pll; + unsigned int vd; + int f_diff; + + fref_div = (2 * p->ref) / rd; + + vd = (f + fref_div / 2) / fref_div; + if (vd < p->vd_min || vd > p->vd_max) + continue; + + f_pll = fref_div * vd; + f_diff = f_pll - f; + if (f_diff < 0) + f_diff = -f_diff; + + if ((unsigned)f_diff < best) { + vco.v = vd - 8; + vco.r = rd - 2; + if (f_diff == 0) + break; + best = f_diff; + } + } + + return vco; +} + +EXPORT_SYMBOL(icst525_khz_to_vco); + +struct icst525_vco +icst525_ps_to_vco(const struct icst525_params *p, unsigned long period) +{ + struct icst525_vco vco = { .s = 1, .v = p->vd_max, .r = p->rd_max }; + unsigned long f, ps; + unsigned int i = 0, rd, best = (unsigned int)-1; + + ps = 1000000000UL / p->vco_max; + + /* + * First, find the PLL output divisor such + * that the PLL output is within spec. + */ + do { + f = period / s2div[idx2s[i]]; + + /* + * f must be between 10MHz and + * 320MHz (5V) or 200MHz (3V) + */ + if (f >= ps && f < 100000) + break; + } while (i < ARRAY_SIZE(idx2s)); + + if (i > ARRAY_SIZE(idx2s)) + return vco; + + vco.s = idx2s[i]; + + ps = 500000000UL / p->ref; + + /* + * Now find the closest divisor combination + * which gives a PLL output of 'f'. + */ + for (rd = p->rd_min; rd <= p->rd_max; rd++) { + unsigned long f_in_div, f_pll; + unsigned int vd; + int f_diff; + + f_in_div = ps * rd; + + vd = (f_in_div + f / 2) / f; + if (vd < p->vd_min || vd > p->vd_max) + continue; + + f_pll = (f_in_div + vd / 2) / vd; + f_diff = f_pll - f; + if (f_diff < 0) + f_diff = -f_diff; + + if ((unsigned)f_diff < best) { + vco.v = vd - 8; + vco.r = rd - 2; + if (f_diff == 0) + break; + best = f_diff; + } + } + + return vco; +} + +EXPORT_SYMBOL(icst525_ps_to_vco); -- cgit v1.2.3-70-g09d2