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author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-03-17 10:11:25 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-03-17 10:11:25 -0700 |
commit | 7b7adc4a016a1decb806eb71ecab98721fa7f146 (patch) | |
tree | 0a6f9a6e5659faa94604fbc575382a18f143c657 /arch/unicore32/kernel/cpu-ucv2.c | |
parent | 31598e8713ef501c8f6aad2e2ec8a9457e8877c1 (diff) | |
parent | 289d6b0e287e0acd85f3e6b7ea6c2cb5c234909a (diff) | |
download | linux-7b7adc4a016a1decb806eb71ecab98721fa7f146.tar.bz2 |
Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/epip/linux-2.6-unicore32
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/epip/linux-2.6-unicore32: (40 commits)
unicore32: rewrite arch-specific tlb.h to use asm-generic version
unicore32: modify io_p2v and io_v2p macros, and adjust PKUNITY_mmio_BASEs
unicore32: replace unicore32-specific iomap functions with generic lib implementation
unicore32 machine related: add frame buffer driver for pkunity-v3 soc
unicore32 machine related files: add i2c bus drivers for pkunity-v3 soc
unicore32 io: redefine __REG(x) and re-use readl/writel funcs
unicore32 i8042 upgrade and bugfix: adjust resource request region type
unicore32 upgrade to v2.6.38-rc5: add one more paramter for pte_alloc_map call
unicore32 i8042: adjust io funcs of i8042-unicore32io.h
unicore32: rename PKUNITY_IOSPACE_BASE to PKUNITY_MMIO_BASE
unicore32: modify function names and parameters for irq_chips
unicore32: remove unused lines in arch/unicore32/include/asm/irq.h
unicore32 time.c: change calculate method for clock_event_device
unicore32: ADD MAINTAINER for unicore32 architecture
unicore32 machine related files: ps2 driver
unicore32 machine related files: pci bus handling
unicore32 machine related files: hardware registers
unicore32 machine related files: core files
unicore32 additional architecture files: boot process
unicore32 additional architecture files: low-level lib: misc
...
Acked-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/unicore32/kernel/cpu-ucv2.c')
-rw-r--r-- | arch/unicore32/kernel/cpu-ucv2.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/arch/unicore32/kernel/cpu-ucv2.c b/arch/unicore32/kernel/cpu-ucv2.c new file mode 100644 index 000000000000..4a99f62584c7 --- /dev/null +++ b/arch/unicore32/kernel/cpu-ucv2.c @@ -0,0 +1,93 @@ +/* + * linux/arch/unicore32/kernel/cpu-ucv2.c: clock scaling for the UniCore-II + * + * Code specific to PKUnity SoC and UniCore ISA + * + * Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn> + * Copyright (C) 2001-2010 Guan Xuetao + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/kernel.h> +#include <linux/types.h> +#include <linux/init.h> +#include <linux/clk.h> +#include <linux/cpufreq.h> + +#include <mach/hardware.h> + +static struct cpufreq_driver ucv2_driver; + +/* make sure that only the "userspace" governor is run + * -- anything else wouldn't make sense on this platform, anyway. + */ +int ucv2_verify_speed(struct cpufreq_policy *policy) +{ + if (policy->cpu) + return -EINVAL; + + cpufreq_verify_within_limits(policy, + policy->cpuinfo.min_freq, policy->cpuinfo.max_freq); + + return 0; +} + +static unsigned int ucv2_getspeed(unsigned int cpu) +{ + struct clk *mclk = clk_get(NULL, "MAIN_CLK"); + + if (cpu) + return 0; + return clk_get_rate(mclk)/1000; +} + +static int ucv2_target(struct cpufreq_policy *policy, + unsigned int target_freq, + unsigned int relation) +{ + unsigned int cur = ucv2_getspeed(0); + struct cpufreq_freqs freqs; + struct clk *mclk = clk_get(NULL, "MAIN_CLK"); + + cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); + + if (!clk_set_rate(mclk, target_freq * 1000)) { + freqs.old = cur; + freqs.new = target_freq; + freqs.cpu = 0; + } + + cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); + + return 0; +} + +static int __init ucv2_cpu_init(struct cpufreq_policy *policy) +{ + if (policy->cpu != 0) + return -EINVAL; + policy->cur = ucv2_getspeed(0); + policy->min = policy->cpuinfo.min_freq = 250000; + policy->max = policy->cpuinfo.max_freq = 1000000; + policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; + return 0; +} + +static struct cpufreq_driver ucv2_driver = { + .flags = CPUFREQ_STICKY, + .verify = ucv2_verify_speed, + .target = ucv2_target, + .get = ucv2_getspeed, + .init = ucv2_cpu_init, + .name = "UniCore-II", +}; + +static int __init ucv2_cpufreq_init(void) +{ + return cpufreq_register_driver(&ucv2_driver); +} + +arch_initcall(ucv2_cpufreq_init); |