From 9c38cf44712af95a5ec3937d63faaea9b43eab9a Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Wed, 15 Jan 2014 10:31:52 +0000 Subject: 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 Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/6361/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/mips-cpc.c | 52 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 arch/mips/kernel/mips-cpc.c (limited to 'arch/mips/kernel/mips-cpc.c') diff --git a/arch/mips/kernel/mips-cpc.c b/arch/mips/kernel/mips-cpc.c new file mode 100644 index 000000000000..c9dc67402969 --- /dev/null +++ b/arch/mips/kernel/mips-cpc.c @@ -0,0 +1,52 @@ +/* + * Copyright (C) 2013 Imagination Technologies + * Author: Paul Burton + * + * 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 + +#include +#include + +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; +} -- cgit