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Openwrt/target/linux/pxa/patches-2.6.21/010-bkpxa-pxa-cpufreq.patch
Gabor Juhos 7085e5331e refresh 2.6.21 patches 
SVN-Revision: 14454
2009-02-08 19:36:13 +00:00

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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 <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <linux/cpufreq.h>
+
+#include <asm/hardware.h>
+#include <asm/arch/pxa-regs.h>
+
+#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<NUM_RUN_FREQS;i++) {
+ pxa255_run_freq_table[i].frequency = pxa255_run_freqs[i].khz;
+ pxa255_run_freq_table[i].index = i;
+ }
+ pxa255_run_freq_table[i].frequency = CPUFREQ_TABLE_END;
+ /* Generate the turbo cpufreq_frequency_table struct */
+ for(i=0;i<NUM_TURBO_FREQS;i++) {
+ pxa255_turbo_freq_table[i].frequency = pxa255_turbo_freqs[i].khz;
+ pxa255_turbo_freq_table[i].index = i;
+ }
+ pxa255_turbo_freq_table[i].frequency = CPUFREQ_TABLE_END;
+
+ set_cpus_allowed(current, cpus_allowed);
+ printk(KERN_INFO "PXA CPU frequency change support initialized\n");
+
+ return 0;
+}
+
+static struct cpufreq_driver pxa_cpufreq_driver = {
+ .verify = pxa_verify_policy,
+ .target = pxa_set_target,
+ .init = pxa_cpufreq_init,
+ .name = "PXA25x",
+};
+
+static int __init pxa_cpu_init(void)
+{
+ return cpufreq_register_driver(&pxa_cpufreq_driver);
+}
+
+static void __exit pxa_cpu_exit(void)
+{
+ cpufreq_unregister_driver(&pxa_cpufreq_driver);
+}
+
+
+MODULE_AUTHOR ("Intrinsyc Software Inc.");
+MODULE_DESCRIPTION ("CPU frequency changing driver for the PXA architecture");
+MODULE_LICENSE("GPL");
+module_init(pxa_cpu_init);
+module_exit(pxa_cpu_exit);
+
--- a/Documentation/cpu-freq/user-guide.txt
+++ b/Documentation/cpu-freq/user-guide.txt
@@ -18,7 +18,7 @@
Contents:
---------
1. Supported Architectures and Processors
-1.1 ARM
+1.1 ARM, PXA
1.2 x86
1.3 sparc64
1.4 ppc
@@ -37,14 +37,15 @@ Contents:
1. Supported Architectures and Processors
=========================================
-1.1 ARM
--------
+1.1 ARM, PXA
+------------
The following ARM processors are supported by cpufreq:
ARM Integrator
ARM-SA1100
ARM-SA1110
+Intel PXA
1.2 x86
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