linux/arch/mips/kernel/mips-cpc.c
Paul Burton 9c38cf4471 MIPS: Add CPC probe, access functions
This patch introduces code to probe for a MIPS Cluster Power Controller
& accessor functions to allow for easy register access. This support
code will be used by a subsequent patch.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6361/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-03-06 21:25:23 +01:00

53 lines
1.2 KiB
C

/*
* Copyright (C) 2013 Imagination Technologies
* Author: Paul Burton <paul.burton@imgtec.com>
*
* 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/errno.h>
#include <asm/mips-cm.h>
#include <asm/mips-cpc.h>
void __iomem *mips_cpc_base;
phys_t __weak mips_cpc_phys_base(void)
{
u32 cpc_base;
if (!mips_cm_present())
return 0;
if (!(read_gcr_cpc_status() & CM_GCR_CPC_STATUS_EX_MSK))
return 0;
/* If the CPC is already enabled, leave it so */
cpc_base = read_gcr_cpc_base();
if (cpc_base & CM_GCR_CPC_BASE_CPCEN_MSK)
return cpc_base & CM_GCR_CPC_BASE_CPCBASE_MSK;
/* Otherwise, give it the default address & enable it */
cpc_base = mips_cpc_default_phys_base();
write_gcr_cpc_base(cpc_base | CM_GCR_CPC_BASE_CPCEN_MSK);
return cpc_base;
}
int mips_cpc_probe(void)
{
phys_t addr;
addr = mips_cpc_phys_base();
if (!addr)
return -ENODEV;
mips_cpc_base = ioremap_nocache(addr, 0x8000);
if (!mips_cpc_base)
return -ENXIO;
return 0;
}