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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/ppc/syslib/ibm440gp_common.c
downloadop-kernel-dev-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip
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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/ppc/syslib/ibm440gp_common.c')
-rw-r--r--arch/ppc/syslib/ibm440gp_common.c76
1 files changed, 76 insertions, 0 deletions
diff --git a/arch/ppc/syslib/ibm440gp_common.c b/arch/ppc/syslib/ibm440gp_common.c
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+++ b/arch/ppc/syslib/ibm440gp_common.c
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+/*
+ * arch/ppc/syslib/ibm440gp_common.c
+ *
+ * PPC440GP system library
+ *
+ * Matt Porter <mporter@mvista.com>
+ * Copyright 2002-2003 MontaVista Software Inc.
+ *
+ * Eugene Surovegin <eugene.surovegin@zultys.com> or <ebs@ebshome.net>
+ * Copyright (c) 2003 Zultys Technologies
+ *
+ * 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.
+ *
+ */
+#include <linux/config.h>
+#include <linux/types.h>
+#include <asm/reg.h>
+#include <asm/ibm44x.h>
+#include <asm/mmu.h>
+
+/*
+ * Calculate 440GP clocks
+ */
+void __init ibm440gp_get_clocks(struct ibm44x_clocks* p,
+ unsigned int sys_clk,
+ unsigned int ser_clk)
+{
+ u32 cpc0_sys0 = mfdcr(DCRN_CPC0_SYS0);
+ u32 cpc0_cr0 = mfdcr(DCRN_CPC0_CR0);
+ u32 opdv = ((cpc0_sys0 >> 10) & 0x3) + 1;
+ u32 epdv = ((cpc0_sys0 >> 8) & 0x3) + 1;
+
+ if (cpc0_sys0 & 0x2){
+ /* Bypass system PLL */
+ p->cpu = p->plb = sys_clk;
+ }
+ else {
+ u32 fbdv, fwdva, fwdvb, m, vco;
+
+ fbdv = (cpc0_sys0 >> 18) & 0x0f;
+ if (!fbdv)
+ fbdv = 16;
+
+ fwdva = 8 - ((cpc0_sys0 >> 15) & 0x7);
+ fwdvb = 8 - ((cpc0_sys0 >> 12) & 0x7);
+
+ /* Feedback path */
+ if (cpc0_sys0 & 0x00000080){
+ /* PerClk */
+ m = fwdvb * opdv * epdv;
+ }
+ else {
+ /* CPU clock */
+ m = fbdv * fwdva;
+ }
+ vco = sys_clk * m;
+ p->cpu = vco / fwdva;
+ p->plb = vco / fwdvb;
+ }
+
+ p->opb = p->plb / opdv;
+ p->ebc = p->opb / epdv;
+
+ if (cpc0_cr0 & 0x00400000){
+ /* External UART clock */
+ p->uart0 = p->uart1 = ser_clk;
+ }
+ else {
+ /* Internal UART clock */
+ u32 uart_div = ((cpc0_cr0 >> 16) & 0x1f) + 1;
+ p->uart0 = p->uart1 = p->plb / uart_div;
+ }
+}
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