Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / cpufreq / sc520_freq.c

diff --git a/kernel/drivers/cpufreq/sc520_freq.c b/kernel/drivers/cpufreq/sc520_freq.c
new file mode 100644 (file)
index 0000000..ac84e48
--- /dev/null
+++ b/kernel/drivers/cpufreq/sc520_freq.c
@@ -0,0 +1,140 @@
+/*
+ *     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[] = {
+       {0, 0x01,       100000},
+       {0, 0x02,       133000},
+       {0, 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 int sc520_freq_target(struct cpufreq_policy *policy, unsigned int state)
+{
+
+       u8 clockspeed_reg;
+
+       local_irq_disable();
+
+       clockspeed_reg = *cpuctl & ~0x03;
+       *cpuctl = clockspeed_reg | sc520_freq_table[state].driver_data;
+
+       local_irq_enable();
+
+       return 0;
+}
+
+/*
+ *     Module init and exit code
+ */
+
+static int sc520_freq_cpu_init(struct cpufreq_policy *policy)
+{
+       struct cpuinfo_x86 *c = &cpu_data(0);
+
+       /* 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 */
+
+       return cpufreq_table_validate_and_show(policy, sc520_freq_table);
+}
+
+
+static struct cpufreq_driver sc520_freq_driver = {
+       .get    = sc520_freq_get_cpu_frequency,
+       .verify = cpufreq_generic_frequency_table_verify,
+       .target_index = sc520_freq_target,
+       .init   = sc520_freq_cpu_init,
+       .name   = "sc520_freq",
+       .attr   = cpufreq_generic_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);
+