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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /drivers/cpufreq/sc520_freq.c | |
parent | Initial commit. (diff) | |
download | linux-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/sc520_freq.c')
-rw-r--r-- | drivers/cpufreq/sc520_freq.c | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/drivers/cpufreq/sc520_freq.c b/drivers/cpufreq/sc520_freq.c new file mode 100644 index 000000000..abaa75e86 --- /dev/null +++ b/drivers/cpufreq/sc520_freq.c @@ -0,0 +1,141 @@ +/* + * 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 + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#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; + +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: + pr_err("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 */ + policy->freq_table = sc520_freq_table; + + return 0; +} + + +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) { + pr_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); + |