linux-hardened/arch/mips/au1000/common/cputable.c
Sergei Shtylyov 758e285fac [MIPS] Alchemy: work around clock misdetection on early Au1000
Work around the CPU clock miscalculation on Au1000DA/HA/HB due the
sys_cpupll register being write-only, i.e. actually do what the comment
before cal_r4off() function advertised for years but the code failed at.
This is achieved by just giving user a chance to define the clock
explicitly  in the board config. via CONFIG_SOC_AU1000_FREQUENCY option,
defaulting to 396 MHz if the option is not given...

The patch is based on the AMD's big unpublished patch, the issue seems to
be an undocumented errata (or feature :-)...

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-04-01 15:46:34 +01:00

56 lines
1.8 KiB
C

/*
* arch/mips/au1000/common/cputable.c
*
* Copyright (C) 2004 Dan Malek (dan@embeddededge.com)
* Copied from PowerPC and updated for Alchemy Au1xxx processors.
*
* Copyright (C) 2001 Ben. Herrenschmidt (benh@kernel.crashing.org)
*
* 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/string.h>
#include <linux/sched.h>
#include <linux/threads.h>
#include <linux/init.h>
#include <asm/mach-au1x00/au1000.h>
struct cpu_spec* cur_cpu_spec[NR_CPUS];
/* With some thought, we can probably use the mask to reduce the
* size of the table.
*/
struct cpu_spec cpu_specs[] = {
{ 0xffffffff, 0x00030100, "Au1000 DA", 1, 0, 1 },
{ 0xffffffff, 0x00030201, "Au1000 HA", 1, 0, 1 },
{ 0xffffffff, 0x00030202, "Au1000 HB", 1, 0, 1 },
{ 0xffffffff, 0x00030203, "Au1000 HC", 1, 1, 0 },
{ 0xffffffff, 0x00030204, "Au1000 HD", 1, 1, 0 },
{ 0xffffffff, 0x01030200, "Au1500 AB", 1, 1, 0 },
{ 0xffffffff, 0x01030201, "Au1500 AC", 0, 1, 0 },
{ 0xffffffff, 0x01030202, "Au1500 AD", 0, 1, 0 },
{ 0xffffffff, 0x02030200, "Au1100 AB", 1, 1, 0 },
{ 0xffffffff, 0x02030201, "Au1100 BA", 1, 1, 0 },
{ 0xffffffff, 0x02030202, "Au1100 BC", 1, 1, 0 },
{ 0xffffffff, 0x02030203, "Au1100 BD", 0, 1, 0 },
{ 0xffffffff, 0x02030204, "Au1100 BE", 0, 1, 0 },
{ 0xffffffff, 0x03030200, "Au1550 AA", 0, 1, 0 },
{ 0xffffffff, 0x04030200, "Au1200 AB", 0, 0, 0 },
{ 0xffffffff, 0x04030201, "Au1200 AC", 1, 0, 0 },
{ 0x00000000, 0x00000000, "Unknown Au1xxx", 1, 0, 0 }
};
void
set_cpuspec(void)
{
struct cpu_spec *sp;
u32 prid;
prid = read_c0_prid();
sp = cpu_specs;
while ((prid & sp->prid_mask) != sp->prid_value)
sp++;
cur_cpu_spec[0] = sp;
}