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authorLinus Torvalds <torvalds@linux-foundation.org>2011-03-17 10:11:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-03-17 10:11:25 -0700
commit7b7adc4a016a1decb806eb71ecab98721fa7f146 (patch)
tree0a6f9a6e5659faa94604fbc575382a18f143c657 /arch/unicore32/kernel/cpu-ucv2.c
parent31598e8713ef501c8f6aad2e2ec8a9457e8877c1 (diff)
parent289d6b0e287e0acd85f3e6b7ea6c2cb5c234909a (diff)
downloadlinux-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.c93
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);