Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame] | 2 | * elanfreq: cpufreq driver for the AMD ELAN family |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3 | * |
| 4 | * (c) Copyright 2002 Robert Schwebel <r.schwebel@pengutronix.de> |
| 5 | * |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame] | 6 | * Parts of this code are (c) Sven Geggus <sven@geggus.net> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 7 | * |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame] | 8 | * All Rights Reserved. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 9 | * |
| 10 | * This program is free software; you can redistribute it and/or |
| 11 | * modify it under the terms of the GNU General Public License |
| 12 | * as published by the Free Software Foundation; either version |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame] | 13 | * 2 of the License, or (at your option) any later version. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 14 | * |
| 15 | * 2002-02-13: - initial revision for 2.4.18-pre9 by Robert Schwebel |
| 16 | * |
| 17 | */ |
| 18 | |
| 19 | #include <linux/kernel.h> |
| 20 | #include <linux/module.h> |
| 21 | #include <linux/init.h> |
| 22 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | #include <linux/delay.h> |
| 24 | #include <linux/cpufreq.h> |
| 25 | |
Andi Kleen | fa8031a | 2012-01-26 00:09:12 +0100 | [diff] [blame] | 26 | #include <asm/cpu_device_id.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | #include <asm/msr.h> |
Paolo Ciarrocchi | 18c6faa | 2008-07-28 13:00:49 +0200 | [diff] [blame] | 28 | #include <linux/timex.h> |
| 29 | #include <linux/io.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame] | 31 | #define REG_CSCIR 0x22 /* Chip Setup and Control Index Register */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | #define REG_CSCDR 0x23 /* Chip Setup and Control Data Register */ |
| 33 | |
| 34 | /* Module parameter */ |
| 35 | static int max_freq; |
| 36 | |
| 37 | struct s_elan_multiplier { |
| 38 | int clock; /* frequency in kHz */ |
| 39 | int val40h; /* PMU Force Mode register */ |
| 40 | int val80h; /* CPU Clock Speed Register */ |
| 41 | }; |
| 42 | |
| 43 | /* |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame] | 44 | * It is important that the frequencies |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | * are listed in ascending order here! |
| 46 | */ |
Dave Jones | 460f5ef | 2008-07-30 13:01:42 -0400 | [diff] [blame] | 47 | static struct s_elan_multiplier elan_multiplier[] = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | {1000, 0x02, 0x18}, |
| 49 | {2000, 0x02, 0x10}, |
| 50 | {4000, 0x02, 0x08}, |
| 51 | {8000, 0x00, 0x00}, |
| 52 | {16000, 0x00, 0x02}, |
| 53 | {33000, 0x00, 0x04}, |
| 54 | {66000, 0x01, 0x04}, |
| 55 | {99000, 0x01, 0x05} |
| 56 | }; |
| 57 | |
| 58 | static struct cpufreq_frequency_table elanfreq_table[] = { |
Viresh Kumar | 7f4b046 | 2014-03-28 19:11:47 +0530 | [diff] [blame] | 59 | {0, 0, 1000}, |
| 60 | {0, 1, 2000}, |
| 61 | {0, 2, 4000}, |
| 62 | {0, 3, 8000}, |
| 63 | {0, 4, 16000}, |
| 64 | {0, 5, 33000}, |
| 65 | {0, 6, 66000}, |
| 66 | {0, 7, 99000}, |
| 67 | {0, 0, CPUFREQ_TABLE_END}, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | }; |
| 69 | |
| 70 | |
| 71 | /** |
| 72 | * elanfreq_get_cpu_frequency: determine current cpu speed |
| 73 | * |
| 74 | * Finds out at which frequency the CPU of the Elan SOC runs |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame] | 75 | * at the moment. Frequencies from 1 to 33 MHz are generated |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | * the normal way, 66 and 99 MHz are called "Hyperspeed Mode" |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame] | 77 | * and have the rest of the chip running with 33 MHz. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | */ |
| 79 | |
| 80 | static unsigned int elanfreq_get_cpu_frequency(unsigned int cpu) |
| 81 | { |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame] | 82 | u8 clockspeed_reg; /* Clock Speed Register */ |
| 83 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 84 | local_irq_disable(); |
Paolo Ciarrocchi | 18c6faa | 2008-07-28 13:00:49 +0200 | [diff] [blame] | 85 | outb_p(0x80, REG_CSCIR); |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame] | 86 | clockspeed_reg = inb_p(REG_CSCDR); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 87 | local_irq_enable(); |
| 88 | |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame] | 89 | if ((clockspeed_reg & 0xE0) == 0xE0) |
| 90 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame] | 92 | /* Are we in CPU clock multiplied mode (66/99 MHz)? */ |
| 93 | if ((clockspeed_reg & 0xE0) == 0xC0) { |
| 94 | if ((clockspeed_reg & 0x01) == 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 95 | return 66000; |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame] | 96 | else |
| 97 | return 99000; |
| 98 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | |
| 100 | /* 33 MHz is not 32 MHz... */ |
Paolo Ciarrocchi | 18c6faa | 2008-07-28 13:00:49 +0200 | [diff] [blame] | 101 | if ((clockspeed_reg & 0xE0) == 0xA0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | return 33000; |
| 103 | |
Paolo Ciarrocchi | 18c6faa | 2008-07-28 13:00:49 +0200 | [diff] [blame] | 104 | return (1<<((clockspeed_reg & 0xE0) >> 5)) * 1000; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 105 | } |
| 106 | |
| 107 | |
Viresh Kumar | 9c0ebcf | 2013-10-25 19:45:48 +0530 | [diff] [blame] | 108 | static int elanfreq_target(struct cpufreq_policy *policy, |
| 109 | unsigned int state) |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame] | 110 | { |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame] | 111 | /* |
| 112 | * Access to the Elan's internal registers is indexed via |
| 113 | * 0x22: Chip Setup & Control Register Index Register (CSCI) |
| 114 | * 0x23: Chip Setup & Control Register Data Register (CSCD) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 115 | * |
| 116 | */ |
| 117 | |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame] | 118 | /* |
| 119 | * 0x40 is the Power Management Unit's Force Mode Register. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | * Bit 6 enables Hyperspeed Mode (66/100 MHz core frequency) |
| 121 | */ |
| 122 | |
| 123 | local_irq_disable(); |
Paolo Ciarrocchi | 18c6faa | 2008-07-28 13:00:49 +0200 | [diff] [blame] | 124 | outb_p(0x40, REG_CSCIR); /* Disable hyperspeed mode */ |
| 125 | outb_p(0x00, REG_CSCDR); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 126 | local_irq_enable(); /* wait till internal pipelines and */ |
| 127 | udelay(1000); /* buffers have cleaned up */ |
| 128 | |
| 129 | local_irq_disable(); |
| 130 | |
| 131 | /* now, set the CPU clock speed register (0x80) */ |
Paolo Ciarrocchi | 18c6faa | 2008-07-28 13:00:49 +0200 | [diff] [blame] | 132 | outb_p(0x80, REG_CSCIR); |
| 133 | outb_p(elan_multiplier[state].val80h, REG_CSCDR); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | |
| 135 | /* now, the hyperspeed bit in PMU Force Mode Register (0x40) */ |
Paolo Ciarrocchi | 18c6faa | 2008-07-28 13:00:49 +0200 | [diff] [blame] | 136 | outb_p(0x40, REG_CSCIR); |
| 137 | outb_p(elan_multiplier[state].val40h, REG_CSCDR); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | udelay(10000); |
| 139 | local_irq_enable(); |
| 140 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | return 0; |
| 142 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | /* |
| 144 | * Module init and exit code |
| 145 | */ |
| 146 | |
| 147 | static int elanfreq_cpu_init(struct cpufreq_policy *policy) |
| 148 | { |
Mike Travis | 92cb761 | 2007-10-19 20:35:04 +0200 | [diff] [blame] | 149 | struct cpuinfo_x86 *c = &cpu_data(0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | unsigned int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 151 | |
| 152 | /* capability check */ |
| 153 | if ((c->x86_vendor != X86_VENDOR_AMD) || |
Paolo Ciarrocchi | 18c6faa | 2008-07-28 13:00:49 +0200 | [diff] [blame] | 154 | (c->x86 != 4) || (c->x86_model != 10)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | return -ENODEV; |
| 156 | |
| 157 | /* max freq */ |
| 158 | if (!max_freq) |
| 159 | max_freq = elanfreq_get_cpu_frequency(0); |
| 160 | |
| 161 | /* table init */ |
Paolo Ciarrocchi | 18c6faa | 2008-07-28 13:00:49 +0200 | [diff] [blame] | 162 | for (i = 0; (elanfreq_table[i].frequency != CPUFREQ_TABLE_END); i++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 163 | if (elanfreq_table[i].frequency > max_freq) |
| 164 | elanfreq_table[i].frequency = CPUFREQ_ENTRY_INVALID; |
| 165 | } |
| 166 | |
| 167 | /* cpuinfo and default policy values */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 168 | policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 169 | |
Viresh Kumar | 55bb85b | 2013-09-16 18:56:15 +0530 | [diff] [blame] | 170 | return cpufreq_table_validate_and_show(policy, elanfreq_table); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 171 | } |
| 172 | |
| 173 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 174 | #ifndef MODULE |
| 175 | /** |
| 176 | * elanfreq_setup - elanfreq command line parameter parsing |
| 177 | * |
| 178 | * elanfreq command line parameter. Use: |
| 179 | * elanfreq=66000 |
| 180 | * to set the maximum CPU frequency to 66 MHz. Note that in |
| 181 | * case you do not give this boot parameter, the maximum |
| 182 | * frequency will fall back to _current_ CPU frequency which |
| 183 | * might be lower. If you build this as a module, use the |
| 184 | * max_freq module parameter instead. |
| 185 | */ |
| 186 | static int __init elanfreq_setup(char *str) |
| 187 | { |
| 188 | max_freq = simple_strtoul(str, &str, 0); |
| 189 | printk(KERN_WARNING "You're using the deprecated elanfreq command line option. Use elanfreq.max_freq instead, please!\n"); |
| 190 | return 1; |
| 191 | } |
| 192 | __setup("elanfreq=", elanfreq_setup); |
| 193 | #endif |
| 194 | |
| 195 | |
Linus Torvalds | 221dee2 | 2007-02-26 14:55:48 -0800 | [diff] [blame] | 196 | static struct cpufreq_driver elanfreq_driver = { |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame] | 197 | .get = elanfreq_get_cpu_frequency, |
Viresh Kumar | 06494eb | 2013-10-03 20:28:05 +0530 | [diff] [blame] | 198 | .verify = cpufreq_generic_frequency_table_verify, |
Viresh Kumar | 9c0ebcf | 2013-10-25 19:45:48 +0530 | [diff] [blame] | 199 | .target_index = elanfreq_target, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | .init = elanfreq_cpu_init, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 201 | .name = "elanfreq", |
Viresh Kumar | 06494eb | 2013-10-03 20:28:05 +0530 | [diff] [blame] | 202 | .attr = cpufreq_generic_attr, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 203 | }; |
| 204 | |
Andi Kleen | fa8031a | 2012-01-26 00:09:12 +0100 | [diff] [blame] | 205 | static const struct x86_cpu_id elan_id[] = { |
| 206 | { X86_VENDOR_AMD, 4, 10, }, |
| 207 | {} |
| 208 | }; |
| 209 | MODULE_DEVICE_TABLE(x86cpu, elan_id); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 210 | |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame] | 211 | static int __init elanfreq_init(void) |
| 212 | { |
Andi Kleen | fa8031a | 2012-01-26 00:09:12 +0100 | [diff] [blame] | 213 | if (!x86_match_cpu(elan_id)) |
Paolo Ciarrocchi | 18c6faa | 2008-07-28 13:00:49 +0200 | [diff] [blame] | 214 | return -ENODEV; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | return cpufreq_register_driver(&elanfreq_driver); |
| 216 | } |
| 217 | |
| 218 | |
Dave Jones | 32ee8c3 | 2006-02-28 00:43:23 -0500 | [diff] [blame] | 219 | static void __exit elanfreq_exit(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 220 | { |
| 221 | cpufreq_unregister_driver(&elanfreq_driver); |
| 222 | } |
| 223 | |
| 224 | |
Paolo Ciarrocchi | 18c6faa | 2008-07-28 13:00:49 +0200 | [diff] [blame] | 225 | module_param(max_freq, int, 0444); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 226 | |
| 227 | MODULE_LICENSE("GPL"); |
Dave Jones | 04cd1a9 | 2009-01-17 22:50:33 -0500 | [diff] [blame] | 228 | MODULE_AUTHOR("Robert Schwebel <r.schwebel@pengutronix.de>, " |
| 229 | "Sven Geggus <sven@geggus.net>"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 230 | MODULE_DESCRIPTION("cpufreq driver for AMD's Elan CPUs"); |
| 231 | |
| 232 | module_init(elanfreq_init); |
| 233 | module_exit(elanfreq_exit); |