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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /drivers/cpufreq/unicore2-cpufreq.c
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/cpufreq/unicore2-cpufreq.c')
-rw-r--r--drivers/cpufreq/unicore2-cpufreq.c79
1 files changed, 79 insertions, 0 deletions
diff --git a/drivers/cpufreq/unicore2-cpufreq.c b/drivers/cpufreq/unicore2-cpufreq.c
new file mode 100644
index 000000000..db62d9844
--- /dev/null
+++ b/drivers/cpufreq/unicore2-cpufreq.c
@@ -0,0 +1,79 @@
+/*
+ * 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/err.h>
+#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.
+ */
+static int ucv2_verify_speed(struct cpufreq_policy *policy)
+{
+ if (policy->cpu)
+ return -EINVAL;
+
+ cpufreq_verify_within_cpu_limits(policy);
+ return 0;
+}
+
+static int ucv2_target(struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ unsigned int relation)
+{
+ struct cpufreq_freqs freqs;
+ int ret;
+
+ freqs.old = policy->cur;
+ freqs.new = target_freq;
+
+ cpufreq_freq_transition_begin(policy, &freqs);
+ ret = clk_set_rate(policy->clk, target_freq * 1000);
+ cpufreq_freq_transition_end(policy, &freqs, ret);
+
+ return ret;
+}
+
+static int __init ucv2_cpu_init(struct cpufreq_policy *policy)
+{
+ if (policy->cpu != 0)
+ return -EINVAL;
+
+ policy->min = policy->cpuinfo.min_freq = 250000;
+ policy->max = policy->cpuinfo.max_freq = 1000000;
+ policy->clk = clk_get(NULL, "MAIN_CLK");
+ return PTR_ERR_OR_ZERO(policy->clk);
+}
+
+static struct cpufreq_driver ucv2_driver = {
+ .flags = CPUFREQ_STICKY | CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING,
+ .verify = ucv2_verify_speed,
+ .target = ucv2_target,
+ .get = cpufreq_generic_get,
+ .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);