zte's code,first commit
Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/drivers/cpufreq/sc520_freq.c b/ap/os/linux/linux-3.4.x/drivers/cpufreq/sc520_freq.c
new file mode 100644
index 0000000..e42e073
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/drivers/cpufreq/sc520_freq.c
@@ -0,0 +1,194 @@
+/*
+ * sc520_freq.c: cpufreq driver for the AMD Elan sc520
+ *
+ * Copyright (C) 2005 Sean Young <sean@mess.org>
+ *
+ * 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.
+ *
+ * Based on elanfreq.c
+ *
+ * 2005-03-30: - initial revision
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+
+#include <linux/delay.h>
+#include <linux/cpufreq.h>
+#include <linux/timex.h>
+#include <linux/io.h>
+
+#include <asm/cpu_device_id.h>
+#include <asm/msr.h>
+
+#define MMCR_BASE 0xfffef000 /* The default base address */
+#define OFFS_CPUCTL 0x2 /* CPU Control Register */
+
+static __u8 __iomem *cpuctl;
+
+#define PFX "sc520_freq: "
+
+static struct cpufreq_frequency_table sc520_freq_table[] = {
+ {0x01, 100000},
+ {0x02, 133000},
+ {0, CPUFREQ_TABLE_END},
+};
+
+static unsigned int sc520_freq_get_cpu_frequency(unsigned int cpu)
+{
+ u8 clockspeed_reg = *cpuctl;
+
+ switch (clockspeed_reg & 0x03) {
+ default:
+ printk(KERN_ERR PFX "error: cpuctl register has unexpected "
+ "value %02x\n", clockspeed_reg);
+ case 0x01:
+ return 100000;
+ case 0x02:
+ return 133000;
+ }
+}
+
+static void sc520_freq_set_cpu_state(unsigned int state)
+{
+
+ struct cpufreq_freqs freqs;
+ u8 clockspeed_reg;
+
+ freqs.old = sc520_freq_get_cpu_frequency(0);
+ freqs.new = sc520_freq_table[state].frequency;
+ freqs.cpu = 0; /* AMD Elan is UP */
+
+ cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+
+ pr_debug("attempting to set frequency to %i kHz\n",
+ sc520_freq_table[state].frequency);
+
+ local_irq_disable();
+
+ clockspeed_reg = *cpuctl & ~0x03;
+ *cpuctl = clockspeed_reg | sc520_freq_table[state].index;
+
+ local_irq_enable();
+
+ cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+};
+
+static int sc520_freq_verify(struct cpufreq_policy *policy)
+{
+ return cpufreq_frequency_table_verify(policy, &sc520_freq_table[0]);
+}
+
+static int sc520_freq_target(struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ unsigned int relation)
+{
+ unsigned int newstate = 0;
+
+ if (cpufreq_frequency_table_target(policy, sc520_freq_table,
+ target_freq, relation, &newstate))
+ return -EINVAL;
+
+ sc520_freq_set_cpu_state(newstate);
+
+ return 0;
+}
+
+
+/*
+ * Module init and exit code
+ */
+
+static int sc520_freq_cpu_init(struct cpufreq_policy *policy)
+{
+ struct cpuinfo_x86 *c = &cpu_data(0);
+ int result;
+
+ /* capability check */
+ if (c->x86_vendor != X86_VENDOR_AMD ||
+ c->x86 != 4 || c->x86_model != 9)
+ return -ENODEV;
+
+ /* cpuinfo and default policy values */
+ policy->cpuinfo.transition_latency = 1000000; /* 1ms */
+ policy->cur = sc520_freq_get_cpu_frequency(0);
+
+ result = cpufreq_frequency_table_cpuinfo(policy, sc520_freq_table);
+ if (result)
+ return result;
+
+ cpufreq_frequency_table_get_attr(sc520_freq_table, policy->cpu);
+
+ return 0;
+}
+
+
+static int sc520_freq_cpu_exit(struct cpufreq_policy *policy)
+{
+ cpufreq_frequency_table_put_attr(policy->cpu);
+ return 0;
+}
+
+
+static struct freq_attr *sc520_freq_attr[] = {
+ &cpufreq_freq_attr_scaling_available_freqs,
+ NULL,
+};
+
+
+static struct cpufreq_driver sc520_freq_driver = {
+ .get = sc520_freq_get_cpu_frequency,
+ .verify = sc520_freq_verify,
+ .target = sc520_freq_target,
+ .init = sc520_freq_cpu_init,
+ .exit = sc520_freq_cpu_exit,
+ .name = "sc520_freq",
+ .owner = THIS_MODULE,
+ .attr = sc520_freq_attr,
+};
+
+static const struct x86_cpu_id sc520_ids[] = {
+ { X86_VENDOR_AMD, 4, 9 },
+ {}
+};
+MODULE_DEVICE_TABLE(x86cpu, sc520_ids);
+
+static int __init sc520_freq_init(void)
+{
+ int err;
+
+ if (!x86_match_cpu(sc520_ids))
+ return -ENODEV;
+
+ cpuctl = ioremap((unsigned long)(MMCR_BASE + OFFS_CPUCTL), 1);
+ if (!cpuctl) {
+ printk(KERN_ERR "sc520_freq: error: failed to remap memory\n");
+ return -ENOMEM;
+ }
+
+ err = cpufreq_register_driver(&sc520_freq_driver);
+ if (err)
+ iounmap(cpuctl);
+
+ return err;
+}
+
+
+static void __exit sc520_freq_exit(void)
+{
+ cpufreq_unregister_driver(&sc520_freq_driver);
+ iounmap(cpuctl);
+}
+
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Sean Young <sean@mess.org>");
+MODULE_DESCRIPTION("cpufreq driver for AMD's Elan sc520 CPU");
+
+module_init(sc520_freq_init);
+module_exit(sc520_freq_exit);
+