diff options
Diffstat (limited to 'arch/mips/cpu/incaip_clock.c')
| -rw-r--r-- | arch/mips/cpu/incaip_clock.c | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/arch/mips/cpu/incaip_clock.c b/arch/mips/cpu/incaip_clock.c new file mode 100644 index 0000000..fc2c621 --- /dev/null +++ b/arch/mips/cpu/incaip_clock.c @@ -0,0 +1,116 @@ +/* + * (C) Copyright 2003 + * Wolfgang Denk, DENX Software Engineering, wd@denx.de. + * + * See file CREDITS for list of people who contributed to this + * project. + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <common.h> +#include <asm/inca-ip.h> + + +/******************************************************************************* +* +* get_cpuclk - returns the frequency of the CPU. +* +* Gets the value directly from the INCA-IP hardware. +* +* RETURNS: +* 150.000.000 for 150 MHz +* 133.333.333 for 133 MHz (= 400MHz/3) +* 100.000.000 for 100 MHz (= 400MHz/4) +* NOTE: +* This functions should be used by the hardware driver to get the correct +* frequency of the CPU. Don't use the macros, which are set to init the CPU +* frequency in the ROM code. +*/ +uint incaip_get_cpuclk (void) +{ + /*-------------------------------------------------------------------------*/ + /* CPU Clock Input Multiplexer (MUX I) */ + /* Multiplexer MUX I selects the maximum input clock to the CPU. */ + /*-------------------------------------------------------------------------*/ + if (*((volatile ulong *) INCA_IP_CGU_CGU_MUXCR) & + INCA_IP_CGU_CGU_MUXCR_MUXI) { + /* MUX I set to 150 MHz clock */ + return 150000000; + } else { + /* MUX I set to 100/133 MHz clock */ + if (*((volatile ulong *) INCA_IP_CGU_CGU_DIVCR) & 0x40) { + /* Division value is 1/3, maximum CPU operating */ + /* frequency is 133.3 MHz */ + return 133333333; + } else { + /* Division value is 1/4, maximum CPU operating */ + /* frequency is 100 MHz */ + return 100000000; + } + } +} + +/******************************************************************************* +* +* get_fpiclk - returns the frequency of the FPI bus. +* +* Gets the value directly from the INCA-IP hardware. +* +* RETURNS: Frquency in Hz +* +* NOTE: +* This functions should be used by the hardware driver to get the correct +* frequency of the CPU. Don't use the macros, which are set to init the CPU +* frequency in the ROM code. +* The calculation for the +*/ +uint incaip_get_fpiclk (void) +{ + uint clkCPU; + + clkCPU = incaip_get_cpuclk (); + + switch (*((volatile ulong *) INCA_IP_CGU_CGU_DIVCR) & 0xC) { + case 0x4: + return clkCPU >> 1; /* devided by 2 */ + break; + case 0x8: + return clkCPU >> 2; /* devided by 4 */ + break; + default: + return clkCPU; + break; + } +} + +int incaip_set_cpuclk (void) +{ + extern void ebu_init(long); + extern void cgu_init(long); + extern void sdram_init(long); + char tmp[64]; + ulong cpuclk; + + if (getenv_r ("cpuclk", tmp, sizeof (tmp)) > 0) { + cpuclk = simple_strtoul (tmp, NULL, 10) * 1000000; + cgu_init (cpuclk); + ebu_init (cpuclk); + sdram_init (cpuclk); + } + + return 0; +} |