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author | 2015-08-04 12:17:53 -0700 | |
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committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/drivers/cpufreq/sc520_freq.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/drivers/cpufreq/sc520_freq.c')
-rw-r--r-- | kernel/drivers/cpufreq/sc520_freq.c | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/kernel/drivers/cpufreq/sc520_freq.c b/kernel/drivers/cpufreq/sc520_freq.c new file mode 100644 index 000000000..ac84e4818 --- /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); + |