From f8ede0f700f5478851f242f291d203cde54ca6cf Mon Sep 17 00:00:00 2001 From: Wu Zhangjin Date: Tue, 17 Nov 2009 01:32:59 +0800 Subject: MIPS: Loongson 2F: Add CPU frequency scaling support Loongson 2F supports CPU clock scaling. When put it into wait mode by setting the frequency as ZERO it will stay in this mode until an external interrupt wakes the CPU again. To enable clock scaling support, an external timer of a known stable rate is required. Signed-off-by: Wu Zhangjin Cc: linux-mips@linux-mips.org Cc: cpufreq@vger.kernel.org, Cc: Dave Jones , Cc: Dominik Brodowski , Cc: yanh@lemote.com Cc: huhb@lemote.com, Patchwork: http://patchwork.linux-mips.org/patch/660/ Patchwork: http://patchwork.linux-mips.org/patch/751/ Signed-off-by: Ralf Baechle --- arch/mips/loongson/common/platform.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) create mode 100644 arch/mips/loongson/common/platform.c (limited to 'arch/mips/loongson/common/platform.c') diff --git a/arch/mips/loongson/common/platform.c b/arch/mips/loongson/common/platform.c new file mode 100644 index 000000000000..be81777eb94d --- /dev/null +++ b/arch/mips/loongson/common/platform.c @@ -0,0 +1,30 @@ +/* + * Copyright (C) 2009 Lemote Inc. + * Author: Wu Zhangjin, wuzj@lemote.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 +#include + +static struct platform_device loongson2_cpufreq_device = { + .name = "loongson2_cpufreq", + .id = -1, +}; + +static int __init loongson2_cpufreq_init(void) +{ + struct cpuinfo_mips *c = ¤t_cpu_data; + + /* Only 2F revision and it's successors support CPUFreq */ + if ((c->processor_id & PRID_REV_MASK) >= PRID_REV_LOONGSON2F) + return platform_device_register(&loongson2_cpufreq_device); + + return -ENODEV; +} + +arch_initcall(loongson2_cpufreq_init); -- cgit v1.2.3-55-g7522