Status: WORKS PXA CPU frequency change support added mods from Stefan Eletzhofer and Lothar Weissmann # # Patch managed by http://www.mn-logistik.de/unsupported/pxa250/patcher # --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -800,7 +800,7 @@ config KEXEC endmenu -if (ARCH_SA1100 || ARCH_INTEGRATOR || ARCH_OMAP || ARCH_IMX ) +if (ARCH_SA1100 || ARCH_INTEGRATOR || ARCH_OMAP || ARCH_IMX || ARCH_PXA ) menu "CPU Frequency scaling" @@ -838,6 +838,12 @@ config CPU_FREQ_IMX endmenu +config CPU_FREQ_PXA + bool + depends on CPU_FREQ && ARCH_PXA + default y + select CPU_FREQ_DEFAULT_GOV_USERSPACE + endif menu "Floating point emulation" --- a/arch/arm/mach-pxa/Makefile +++ b/arch/arm/mach-pxa/Makefile @@ -32,6 +32,7 @@ obj-$(CONFIG_LEDS) += $(led-y) # Misc features obj-$(CONFIG_PM) += pm.o sleep.o obj-$(CONFIG_PXA_SSP) += ssp.o +obj-$(CONFIG_CPU_FREQ) += cpu-pxa.o ifeq ($(CONFIG_PXA27x),y) obj-$(CONFIG_PM) += standby.o --- /dev/null +++ b/arch/arm/mach-pxa/cpu-pxa.c @@ -0,0 +1,321 @@ +/* + * linux/arch/arm/mach-pxa/cpu-pxa.c + * + * Copyright (C) 2002,2003 Intrinsyc Software + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * History: + * 31-Jul-2002 : Initial version [FB] + * 29-Jan-2003 : added PXA255 support [FB] + * 20-Apr-2003 : ported to v2.5 (Dustin McIntire, Sensoria Corp.) + * + * Note: + * This driver may change the memory bus clock rate, but will not do any + * platform specific access timing changes... for example if you have flash + * memory connected to CS0, you will need to register a platform specific + * notifier which will adjust the memory access strobes to maintain a + * minimum strobe width. + * + */ + +#include +#include +#include +#include +#include + +#include +#include + +#define DEBUG 0 + +#ifdef DEBUG + static unsigned int freq_debug = DEBUG; + MODULE_PARM(freq_debug, "i"); + MODULE_PARM_DESC(freq_debug, "Set the debug messages to on=1/off=0"); +#else + #define freq_debug 0 +#endif + +typedef struct +{ + unsigned int khz; + unsigned int membus; + unsigned int cccr; + unsigned int div2; +} pxa_freqs_t; + +/* Define the refresh period in mSec for the SDRAM and the number of rows */ +#define SDRAM_TREF 64 /* standard 64ms SDRAM */ +#define SDRAM_ROWS 4096 /* 64MB=8192 32MB=4096 */ +#define MDREFR_DRI(x) ((x*SDRAM_TREF)/(SDRAM_ROWS*32)) + +#define CCLKCFG_TURBO 0x1 +#define CCLKCFG_FCS 0x2 +#define PXA25x_MIN_FREQ 99500 +#define PXA25x_MAX_FREQ 398100 +#define MDREFR_DB2_MASK (MDREFR_K2DB2 | MDREFR_K1DB2) +#define MDREFR_DRI_MASK 0xFFF + + +/* Use the run mode frequencies for the CPUFREQ_POLICY_PERFORMANCE policy */ +static pxa_freqs_t pxa255_run_freqs[] = +{ + /* CPU MEMBUS CCCR DIV2*/ + { 99500, 99500, 0x121, 1}, /* run= 99, turbo= 99, PXbus=50, SDRAM=50 */ + {132700, 132700, 0x123, 1}, /* run=133, turbo=133, PXbus=66, SDRAM=66 */ + {199100, 99500, 0x141, 0}, /* run=199, turbo=199, PXbus=99, SDRAM=99 */ + {265400, 132700, 0x143, 1}, /* run=265, turbo=265, PXbus=133, SDRAM=66 */ + {331800, 165900, 0x145, 1}, /* run=331, turbo=331, PXbus=166, SDRAM=83 */ + {398100, 99500, 0x161, 0}, /* run=398, turbo=398, PXbus=196, SDRAM=99 */ + {0,} +}; +#define NUM_RUN_FREQS (sizeof(pxa255_run_freqs)/sizeof(pxa_freqs_t)) + +static struct cpufreq_frequency_table pxa255_run_freq_table[NUM_RUN_FREQS+1]; + +/* Use the turbo mode frequencies for the CPUFREQ_POLICY_POWERSAVE policy */ +static pxa_freqs_t pxa255_turbo_freqs[] = +{ + /* CPU MEMBUS CCCR DIV2*/ + { 99500, 99500, 0x121, 1}, /* run=99, turbo= 99, PXbus=50, SDRAM=50 */ + {199100, 99500, 0x221, 0}, /* run=99, turbo=199, PXbus=50, SDRAM=99 */ + {298500, 99500, 0x321, 0}, /* run=99, turbo=287, PXbus=50, SDRAM=99 */ + {298600, 99500, 0x1c1, 0}, /* run=199, turbo=287, PXbus=99, SDRAM=99 */ + {398100, 99500, 0x241, 0}, /* run=199, turbo=398, PXbus=99, SDRAM=99 */ + {0,} +}; +#define NUM_TURBO_FREQS (sizeof(pxa255_turbo_freqs)/sizeof(pxa_freqs_t)) + +static struct cpufreq_frequency_table pxa255_turbo_freq_table[NUM_TURBO_FREQS+1]; + +extern unsigned get_clk_frequency_khz(int info); + +/* find a valid frequency point */ +static int pxa_verify_policy(struct cpufreq_policy *policy) +{ + int ret; + struct cpufreq_frequency_table *pxa_freqs_table; + + if(policy->policy == CPUFREQ_POLICY_PERFORMANCE) { + pxa_freqs_table = pxa255_run_freq_table; + } else if (policy->policy == CPUFREQ_POLICY_POWERSAVE) { + pxa_freqs_table = pxa255_turbo_freq_table; + } else { + printk("CPU PXA: Unknown policy found. " + "Using CPUFREQ_POLICY_PERFORMANCE\n"); + pxa_freqs_table = pxa255_run_freq_table; + } + ret=cpufreq_frequency_table_verify(policy, pxa_freqs_table); + + if(freq_debug) { + printk("Verified CPU policy: %dKhz min to %dKhz max\n", + policy->min, policy->max); + } + + return ret; +} + +static int pxa_set_target(struct cpufreq_policy *policy, + unsigned int target_freq, + unsigned int relation) +{ + int idx; + unsigned long cpus_allowed; + int cpu = policy->cpu; + struct cpufreq_freqs freqs; + pxa_freqs_t *pxa_freq_settings; + struct cpufreq_frequency_table *pxa_freqs_table; + unsigned long flags; + unsigned int unused; + unsigned int preset_mdrefr, postset_mdrefr; + + /* + * Save this threads cpus_allowed mask. + */ + cpus_allowed = current->cpus_allowed; + + /* + * Bind to the specified CPU. When this call returns, + * we should be running on the right CPU. + */ + set_cpus_allowed(current, 1 << cpu); + BUG_ON(cpu != smp_processor_id()); + + /* Get the current policy */ + if(policy->policy == CPUFREQ_POLICY_PERFORMANCE) { + pxa_freq_settings = pxa255_run_freqs; + pxa_freqs_table = pxa255_run_freq_table; + }else if (policy->policy == CPUFREQ_POLICY_POWERSAVE) { + pxa_freq_settings = pxa255_turbo_freqs; + pxa_freqs_table = pxa255_turbo_freq_table; + }else { + printk("CPU PXA: Unknown policy found. " + "Using CPUFREQ_POLICY_PERFORMANCE\n"); + pxa_freq_settings = pxa255_run_freqs; + pxa_freqs_table = pxa255_run_freq_table; + } + + /* Lookup the next frequency */ + if (cpufreq_frequency_table_target(policy, pxa_freqs_table, + target_freq, relation, &idx)) { + return -EINVAL; + } + + freqs.old = policy->cur; + freqs.new = pxa_freq_settings[idx].khz; + freqs.cpu = policy->cpu; + if(freq_debug) { + printk(KERN_INFO "Changing CPU frequency to %d Mhz, (SDRAM %d Mhz)\n", + freqs.new/1000, (pxa_freq_settings[idx].div2) ? + (pxa_freq_settings[idx].membus/2000) : + (pxa_freq_settings[idx].membus/1000)); + } + + void *ramstart = phys_to_virt(0xa0000000); + + /* + * Tell everyone what we're about to do... + * you should add a notify client with any platform specific + * Vcc changing capability + */ + cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); + + /* Calculate the next MDREFR. If we're slowing down the SDRAM clock + * we need to preset the smaller DRI before the change. If we're speeding + * up we need to set the larger DRI value after the change. + */ + preset_mdrefr = postset_mdrefr = MDREFR; + if((MDREFR & MDREFR_DRI_MASK) > MDREFR_DRI(pxa_freq_settings[idx].membus)) { + preset_mdrefr = (preset_mdrefr & ~MDREFR_DRI_MASK) | + MDREFR_DRI(pxa_freq_settings[idx].membus); + } + postset_mdrefr = (postset_mdrefr & ~MDREFR_DRI_MASK) | + MDREFR_DRI(pxa_freq_settings[idx].membus); + + /* If we're dividing the memory clock by two for the SDRAM clock, this + * must be set prior to the change. Clearing the divide must be done + * after the change. + */ + if(pxa_freq_settings[idx].div2) { + preset_mdrefr |= MDREFR_DB2_MASK; + postset_mdrefr |= MDREFR_DB2_MASK; + } else { + postset_mdrefr &= ~MDREFR_DB2_MASK; + } + + local_irq_save(flags); + + /* Set new the CCCR */ + CCCR = pxa_freq_settings[idx].cccr; + + __asm__ __volatile__(" \ + ldr r4, [%1] ; /* load MDREFR */ \ + b 2f ; \ + .align 5 ; \ +1: \ + str %4, [%1] ; /* preset the MDREFR */ \ + mcr p14, 0, %2, c6, c0, 0 ; /* set CCLKCFG[FCS] */ \ + str %5, [%1] ; /* postset the MDREFR */ \ + \ + b 3f ; \ +2: b 1b ; \ +3: nop ; \ + " + : "=&r" (unused) + : "r" (&MDREFR), "r" (CCLKCFG_TURBO|CCLKCFG_FCS), "r" (ramstart), \ + "r" (preset_mdrefr), "r" (postset_mdrefr) + : "r4", "r5"); + local_irq_restore(flags); + + /* + * Restore the CPUs allowed mask. + */ + set_cpus_allowed(current, cpus_allowed); + + /* + * Tell everyone what we've just done... + * you should add a notify client with any platform specific + * SDRAM refresh timer adjustments + */ + cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); + + return 0; +} + +static int pxa_cpufreq_init(struct cpufreq_policy *policy) +{ + unsigned long cpus_allowed; + unsigned int cpu = policy->cpu; + int i; + + cpus_allowed = current->cpus_allowed; + + set_cpus_allowed(current, 1 << cpu); + BUG_ON(cpu != smp_processor_id()); + + /* set default policy and cpuinfo */ + policy->governor = CPUFREQ_DEFAULT_GOVERNOR; + policy->policy = CPUFREQ_POLICY_PERFORMANCE; + policy->cpuinfo.max_freq = PXA25x_MAX_FREQ; + policy->cpuinfo.min_freq = PXA25x_MIN_FREQ; + policy->cpuinfo.transition_latency = 1000; /* FIXME: 1 ms, assumed */ + policy->cur = get_clk_frequency_khz(0); /* current freq */ + policy->min = policy->max = policy->cur; + + /* Generate the run cpufreq_frequency_table struct */ + for(i=0;i