592eb9997d
PXA cpus maximum frequency depends on the cpu (624 for pxa270, 520 for pxa272, 416 for pxa271). It should be provided on kernel or module start (cpu-pxa pxa27x_maxfreq parameter). Make use of cpufreq_frequency_table_cpuinfo (patch by Bill Reese provided by Philipp Zabel). Some additionnal fixes from Philipp Zabel include : * rename PXA cpufreq driver to reflect added PXA27x support * remove unused variable ramstart from PXA cpufreq driver Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com> Signed-off-by: Robert Jarzmik <rjarzmik@free.fr> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
411 lines
12 KiB
C
411 lines
12 KiB
C
/*
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* linux/arch/arm/mach-pxa/cpu-pxa.c
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*
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* Copyright (C) 2002,2003 Intrinsyc Software
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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* History:
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* 31-Jul-2002 : Initial version [FB]
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* 29-Jan-2003 : added PXA255 support [FB]
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* 20-Apr-2003 : ported to v2.5 (Dustin McIntire, Sensoria Corp.)
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*
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* Note:
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* This driver may change the memory bus clock rate, but will not do any
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* platform specific access timing changes... for example if you have flash
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* memory connected to CS0, you will need to register a platform specific
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* notifier which will adjust the memory access strobes to maintain a
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* minimum strobe width.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/init.h>
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#include <linux/cpufreq.h>
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#include <asm/hardware.h>
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#include <asm/arch/pxa-regs.h>
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#include <asm/arch/pxa2xx-regs.h>
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#ifdef DEBUG
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static unsigned int freq_debug;
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module_param(freq_debug, uint, 0);
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MODULE_PARM_DESC(freq_debug, "Set the debug messages to on=1/off=0");
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#else
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#define freq_debug 0
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#endif
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static unsigned int pxa27x_maxfreq;
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module_param(pxa27x_maxfreq, uint, 0);
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MODULE_PARM_DESC(pxa27x_maxfreq, "Set the pxa27x maxfreq in MHz"
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"(typically 624=>pxa270, 416=>pxa271, 520=>pxa272)");
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typedef struct {
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unsigned int khz;
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unsigned int membus;
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unsigned int cccr;
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unsigned int div2;
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unsigned int cclkcfg;
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} pxa_freqs_t;
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/* Define the refresh period in mSec for the SDRAM and the number of rows */
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#define SDRAM_TREF 64 /* standard 64ms SDRAM */
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#define SDRAM_ROWS 4096 /* 64MB=8192 32MB=4096 */
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#define CCLKCFG_TURBO 0x1
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#define CCLKCFG_FCS 0x2
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#define CCLKCFG_HALFTURBO 0x4
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#define CCLKCFG_FASTBUS 0x8
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#define MDREFR_DB2_MASK (MDREFR_K2DB2 | MDREFR_K1DB2)
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#define MDREFR_DRI_MASK 0xFFF
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/*
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* PXA255 definitions
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*/
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/* Use the run mode frequencies for the CPUFREQ_POLICY_PERFORMANCE policy */
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#define CCLKCFG CCLKCFG_TURBO | CCLKCFG_FCS
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static pxa_freqs_t pxa255_run_freqs[] =
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{
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/* CPU MEMBUS CCCR DIV2 CCLKCFG run turbo PXbus SDRAM */
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{ 99500, 99500, 0x121, 1, CCLKCFG}, /* 99, 99, 50, 50 */
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{132700, 132700, 0x123, 1, CCLKCFG}, /* 133, 133, 66, 66 */
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{199100, 99500, 0x141, 0, CCLKCFG}, /* 199, 199, 99, 99 */
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{265400, 132700, 0x143, 1, CCLKCFG}, /* 265, 265, 133, 66 */
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{331800, 165900, 0x145, 1, CCLKCFG}, /* 331, 331, 166, 83 */
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{398100, 99500, 0x161, 0, CCLKCFG}, /* 398, 398, 196, 99 */
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};
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/* Use the turbo mode frequencies for the CPUFREQ_POLICY_POWERSAVE policy */
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static pxa_freqs_t pxa255_turbo_freqs[] =
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{
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/* CPU MEMBUS CCCR DIV2 CCLKCFG run turbo PXbus SDRAM */
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{ 99500, 99500, 0x121, 1, CCLKCFG}, /* 99, 99, 50, 50 */
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{199100, 99500, 0x221, 0, CCLKCFG}, /* 99, 199, 50, 99 */
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{298500, 99500, 0x321, 0, CCLKCFG}, /* 99, 287, 50, 99 */
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{298600, 99500, 0x1c1, 0, CCLKCFG}, /* 199, 287, 99, 99 */
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{398100, 99500, 0x241, 0, CCLKCFG}, /* 199, 398, 99, 99 */
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};
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#define NUM_PXA25x_RUN_FREQS ARRAY_SIZE(pxa255_run_freqs)
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#define NUM_PXA25x_TURBO_FREQS ARRAY_SIZE(pxa255_turbo_freqs)
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static struct cpufreq_frequency_table
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pxa255_run_freq_table[NUM_PXA25x_RUN_FREQS+1];
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static struct cpufreq_frequency_table
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pxa255_turbo_freq_table[NUM_PXA25x_TURBO_FREQS+1];
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/*
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* PXA270 definitions
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*
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* For the PXA27x:
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* Control variables are A, L, 2N for CCCR; B, HT, T for CLKCFG.
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*
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* A = 0 => memory controller clock from table 3-7,
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* A = 1 => memory controller clock = system bus clock
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* Run mode frequency = 13 MHz * L
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* Turbo mode frequency = 13 MHz * L * N
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* System bus frequency = 13 MHz * L / (B + 1)
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*
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* In CCCR:
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* A = 1
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* L = 16 oscillator to run mode ratio
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* 2N = 6 2 * (turbo mode to run mode ratio)
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*
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* In CCLKCFG:
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* B = 1 Fast bus mode
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* HT = 0 Half-Turbo mode
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* T = 1 Turbo mode
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*
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* For now, just support some of the combinations in table 3-7 of
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* PXA27x Processor Family Developer's Manual to simplify frequency
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* change sequences.
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*/
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#define PXA27x_CCCR(A, L, N2) (A << 25 | N2 << 7 | L)
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#define CCLKCFG2(B, HT, T) \
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(CCLKCFG_FCS | \
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((B) ? CCLKCFG_FASTBUS : 0) | \
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((HT) ? CCLKCFG_HALFTURBO : 0) | \
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((T) ? CCLKCFG_TURBO : 0))
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static pxa_freqs_t pxa27x_freqs[] = {
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{104000, 104000, PXA27x_CCCR(1, 8, 2), 0, CCLKCFG2(1, 0, 1)},
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{156000, 104000, PXA27x_CCCR(1, 8, 6), 0, CCLKCFG2(1, 1, 1)},
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{208000, 208000, PXA27x_CCCR(0, 16, 2), 1, CCLKCFG2(0, 0, 1)},
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{312000, 208000, PXA27x_CCCR(1, 16, 3), 1, CCLKCFG2(1, 0, 1)},
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{416000, 208000, PXA27x_CCCR(1, 16, 4), 1, CCLKCFG2(1, 0, 1)},
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{520000, 208000, PXA27x_CCCR(1, 16, 5), 1, CCLKCFG2(1, 0, 1)},
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{624000, 208000, PXA27x_CCCR(1, 16, 6), 1, CCLKCFG2(1, 0, 1)}
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};
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#define NUM_PXA27x_FREQS ARRAY_SIZE(pxa27x_freqs)
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static struct cpufreq_frequency_table
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pxa27x_freq_table[NUM_PXA27x_FREQS+1];
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extern unsigned get_clk_frequency_khz(int info);
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static void find_freq_tables(struct cpufreq_policy *policy,
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struct cpufreq_frequency_table **freq_table,
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pxa_freqs_t **pxa_freqs)
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{
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if (cpu_is_pxa25x()) {
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if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) {
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*pxa_freqs = pxa255_run_freqs;
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*freq_table = pxa255_run_freq_table;
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} else if (policy->policy == CPUFREQ_POLICY_POWERSAVE) {
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*pxa_freqs = pxa255_turbo_freqs;
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*freq_table = pxa255_turbo_freq_table;
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} else {
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printk("CPU PXA: Unknown policy found. "
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"Using CPUFREQ_POLICY_PERFORMANCE\n");
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*pxa_freqs = pxa255_run_freqs;
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*freq_table = pxa255_run_freq_table;
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}
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}
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if (cpu_is_pxa27x()) {
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*pxa_freqs = pxa27x_freqs;
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*freq_table = pxa27x_freq_table;
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}
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}
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static void pxa27x_guess_max_freq(void)
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{
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if (!pxa27x_maxfreq) {
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pxa27x_maxfreq = 416000;
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printk(KERN_INFO "PXA CPU 27x max frequency not defined "
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"(pxa27x_maxfreq), assuming pxa271 with %dkHz maxfreq\n",
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pxa27x_maxfreq);
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} else {
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pxa27x_maxfreq *= 1000;
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}
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}
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static u32 mdrefr_dri(unsigned int freq)
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{
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u32 dri = 0;
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if (cpu_is_pxa25x())
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dri = ((freq * SDRAM_TREF) / (SDRAM_ROWS * 32));
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if (cpu_is_pxa27x())
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dri = ((freq * SDRAM_TREF) / (SDRAM_ROWS - 31)) / 32;
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return dri;
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}
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/* find a valid frequency point */
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static int pxa_verify_policy(struct cpufreq_policy *policy)
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{
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struct cpufreq_frequency_table *pxa_freqs_table;
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pxa_freqs_t *pxa_freqs;
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int ret;
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find_freq_tables(policy, &pxa_freqs_table, &pxa_freqs);
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ret = cpufreq_frequency_table_verify(policy, pxa_freqs_table);
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if (freq_debug)
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pr_debug("Verified CPU policy: %dKhz min to %dKhz max\n",
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policy->min, policy->max);
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return ret;
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}
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static unsigned int pxa_cpufreq_get(unsigned int cpu)
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{
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return get_clk_frequency_khz(0);
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}
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static int pxa_set_target(struct cpufreq_policy *policy,
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unsigned int target_freq,
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unsigned int relation)
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{
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struct cpufreq_frequency_table *pxa_freqs_table;
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pxa_freqs_t *pxa_freq_settings;
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struct cpufreq_freqs freqs;
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unsigned int idx;
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unsigned long flags;
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unsigned int new_freq_cpu, new_freq_mem;
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unsigned int unused, preset_mdrefr, postset_mdrefr, cclkcfg;
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/* Get the current policy */
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find_freq_tables(policy, &pxa_freqs_table, &pxa_freq_settings);
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/* Lookup the next frequency */
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if (cpufreq_frequency_table_target(policy, pxa_freqs_table,
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target_freq, relation, &idx)) {
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return -EINVAL;
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}
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new_freq_cpu = pxa_freq_settings[idx].khz;
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new_freq_mem = pxa_freq_settings[idx].membus;
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freqs.old = policy->cur;
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freqs.new = new_freq_cpu;
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freqs.cpu = policy->cpu;
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if (freq_debug)
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pr_debug(KERN_INFO "Changing CPU frequency to %d Mhz, "
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"(SDRAM %d Mhz)\n",
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freqs.new / 1000, (pxa_freq_settings[idx].div2) ?
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(new_freq_mem / 2000) : (new_freq_mem / 1000));
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/*
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* Tell everyone what we're about to do...
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* you should add a notify client with any platform specific
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* Vcc changing capability
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*/
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cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
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/* Calculate the next MDREFR. If we're slowing down the SDRAM clock
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* we need to preset the smaller DRI before the change. If we're
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* speeding up we need to set the larger DRI value after the change.
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*/
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preset_mdrefr = postset_mdrefr = MDREFR;
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if ((MDREFR & MDREFR_DRI_MASK) > mdrefr_dri(new_freq_mem)) {
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preset_mdrefr = (preset_mdrefr & ~MDREFR_DRI_MASK);
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preset_mdrefr |= mdrefr_dri(new_freq_mem);
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}
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postset_mdrefr =
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(postset_mdrefr & ~MDREFR_DRI_MASK) | mdrefr_dri(new_freq_mem);
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/* If we're dividing the memory clock by two for the SDRAM clock, this
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* must be set prior to the change. Clearing the divide must be done
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* after the change.
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*/
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if (pxa_freq_settings[idx].div2) {
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preset_mdrefr |= MDREFR_DB2_MASK;
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postset_mdrefr |= MDREFR_DB2_MASK;
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} else {
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postset_mdrefr &= ~MDREFR_DB2_MASK;
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}
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local_irq_save(flags);
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/* Set new the CCCR and prepare CCLKCFG */
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CCCR = pxa_freq_settings[idx].cccr;
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cclkcfg = pxa_freq_settings[idx].cclkcfg;
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asm volatile(" \n\
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ldr r4, [%1] /* load MDREFR */ \n\
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b 2f \n\
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.align 5 \n\
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1: \n\
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str %3, [%1] /* preset the MDREFR */ \n\
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mcr p14, 0, %2, c6, c0, 0 /* set CCLKCFG[FCS] */ \n\
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str %4, [%1] /* postset the MDREFR */ \n\
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\n\
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b 3f \n\
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2: b 1b \n\
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3: nop \n\
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"
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: "=&r" (unused)
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: "r" (&MDREFR), "r" (cclkcfg),
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"r" (preset_mdrefr), "r" (postset_mdrefr)
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: "r4", "r5");
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local_irq_restore(flags);
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/*
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* Tell everyone what we've just done...
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* you should add a notify client with any platform specific
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* SDRAM refresh timer adjustments
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*/
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cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
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return 0;
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}
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static __init int pxa_cpufreq_init(struct cpufreq_policy *policy)
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{
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int i;
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unsigned int freq;
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/* try to guess pxa27x cpu */
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if (cpu_is_pxa27x())
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pxa27x_guess_max_freq();
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/* set default policy and cpuinfo */
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policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
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if (cpu_is_pxa25x())
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policy->policy = CPUFREQ_POLICY_PERFORMANCE;
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policy->cpuinfo.transition_latency = 1000; /* FIXME: 1 ms, assumed */
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policy->cur = get_clk_frequency_khz(0); /* current freq */
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policy->min = policy->max = policy->cur;
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/* Generate pxa25x the run cpufreq_frequency_table struct */
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for (i = 0; i < NUM_PXA25x_RUN_FREQS; i++) {
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pxa255_run_freq_table[i].frequency = pxa255_run_freqs[i].khz;
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pxa255_run_freq_table[i].index = i;
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}
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pxa255_run_freq_table[i].frequency = CPUFREQ_TABLE_END;
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/* Generate pxa25x the turbo cpufreq_frequency_table struct */
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for (i = 0; i < NUM_PXA25x_TURBO_FREQS; i++) {
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pxa255_turbo_freq_table[i].frequency =
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pxa255_turbo_freqs[i].khz;
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pxa255_turbo_freq_table[i].index = i;
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}
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pxa255_turbo_freq_table[i].frequency = CPUFREQ_TABLE_END;
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/* Generate the pxa27x cpufreq_frequency_table struct */
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for (i = 0; i < NUM_PXA27x_FREQS; i++) {
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freq = pxa27x_freqs[i].khz;
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if (freq > pxa27x_maxfreq)
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break;
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pxa27x_freq_table[i].frequency = freq;
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pxa27x_freq_table[i].index = i;
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}
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pxa27x_freq_table[i].frequency = CPUFREQ_TABLE_END;
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/*
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* Set the policy's minimum and maximum frequencies from the tables
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* just constructed. This sets cpuinfo.mxx_freq, min and max.
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*/
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if (cpu_is_pxa25x())
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cpufreq_frequency_table_cpuinfo(policy, pxa255_run_freq_table);
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else if (cpu_is_pxa27x())
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cpufreq_frequency_table_cpuinfo(policy, pxa27x_freq_table);
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printk(KERN_INFO "PXA CPU frequency change support initialized\n");
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return 0;
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}
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static struct cpufreq_driver pxa_cpufreq_driver = {
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.verify = pxa_verify_policy,
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.target = pxa_set_target,
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.init = pxa_cpufreq_init,
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.get = pxa_cpufreq_get,
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.name = "PXA2xx",
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};
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static int __init pxa_cpu_init(void)
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{
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int ret = -ENODEV;
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if (cpu_is_pxa25x() || cpu_is_pxa27x())
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ret = cpufreq_register_driver(&pxa_cpufreq_driver);
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return ret;
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}
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static void __exit pxa_cpu_exit(void)
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{
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cpufreq_unregister_driver(&pxa_cpufreq_driver);
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}
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MODULE_AUTHOR("Intrinsyc Software Inc.");
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MODULE_DESCRIPTION("CPU frequency changing driver for the PXA architecture");
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MODULE_LICENSE("GPL");
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module_init(pxa_cpu_init);
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module_exit(pxa_cpu_exit);
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