3673311619
Add CPU frequency corresponding to SOC. BUG=chrome-os-partner:31438 TEST=tested on Pistachio bring up board; behaves as expected. BRANCH=none Change-Id: I05458070a15c6cf1ef0fc2104715a63902a38887 Signed-off-by: Patrick Georgi <pgeorgi@chromium.org> Original-Commit-Id: 4afe332bcc41afeb7e31e918e345c3336f7dc604 Original-Change-Id: I55b788faf7984bafc2509cac69867a772c7cb863 Original-Signed-off-by: Ionela Voinescu <ionela.voinescu@imgtec.com> Original-Reviewed-on: https://chromium-review.googlesource.com/241427 Original-Reviewed-by: David Hendricks <dhendrix@chromium.org> Reviewed-on: http://review.coreboot.org/8853 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Georgi <pgeorgi@google.com>
56 lines
1.6 KiB
C
56 lines
1.6 KiB
C
/*
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* This file is part of the libpayload project.
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*
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* Copyright (C) 2014 Imagination Technologies
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <libpayload.h>
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#include <arch/cpu.h>
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#include <arch/io.h>
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#define PISTACHIO_CLOCK_SWITCH 0xB8144200
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#define MIPS_EXTERN_PLL_BYPASS_MASK 0x00000002
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/**
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* @ingroup arch
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* Global variable containing the speed of the processor in KHz.
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*/
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u32 cpu_khz;
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/**
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* Calculate the speed of the processor for use in delays.
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*
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* @return The CPU speed in kHz.
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*/
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unsigned int get_cpu_speed(void)
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{
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if (IMG_PLATFORM_ID() != IMG_PLATFORM_ID_SILICON)
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cpu_khz = 50000; /* FPGA board */
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else {
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/* If MIPS PLL external bypass bit is set, it means
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* that the MIPS PLL is already set up to work at a
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* frequency of 550 MHz; otherwise, the crystal is
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* used with a frequency of 52 MHz
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*/
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if (read32(PISTACHIO_CLOCK_SWITCH) &
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MIPS_EXTERN_PLL_BYPASS_MASK)
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cpu_khz = 550000;
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else
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cpu_khz = 52000;
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}
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return cpu_khz;
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}
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