diff options
Diffstat (limited to 'arch/ppc/syslib/ibm440gp_common.c')
| -rw-r--r-- | arch/ppc/syslib/ibm440gp_common.c | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/arch/ppc/syslib/ibm440gp_common.c b/arch/ppc/syslib/ibm440gp_common.c new file mode 100644 index 00000000000..0d6be2d6dd6 --- /dev/null +++ b/arch/ppc/syslib/ibm440gp_common.c @@ -0,0 +1,76 @@ +/* + * 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; + } +} |