Gitweb:     
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=2e0c3370b3ecf831ef209f1094df36a808865845
Commit:     2e0c3370b3ecf831ef209f1094df36a808865845
Parent:     116ab40df8decf8c519368e31825e9584c86adf2
Author:     Olof Johansson <[EMAIL PROTECTED]>
AuthorDate: Fri Apr 27 15:46:01 2007 +1000
Committer:  Paul Mackerras <[EMAIL PROTECTED]>
CommitDate: Fri Apr 27 15:51:57 2007 +1000

    [POWERPC] pasemi: Cpufreq driver
    
    Cpufreq driver for PA Semi PWRficient processors.
    
    Signed-off-by: Egor Martovetsky <[EMAIL PROTECTED]>
    Signed-off-by: Olof Johansson <[EMAIL PROTECTED]>
    Signed-off-by: Paul Mackerras <[EMAIL PROTECTED]>
---
 arch/powerpc/platforms/Kconfig          |   10 +
 arch/powerpc/platforms/pasemi/Makefile  |    1 +
 arch/powerpc/platforms/pasemi/cpufreq.c |  307 +++++++++++++++++++++++++++++++
 arch/powerpc/platforms/pasemi/idle.c    |    9 +
 arch/powerpc/platforms/pasemi/pasemi.h  |    8 +
 5 files changed, 335 insertions(+), 0 deletions(-)

diff --git a/arch/powerpc/platforms/Kconfig b/arch/powerpc/platforms/Kconfig
index ac62fa0..102a44e 100644
--- a/arch/powerpc/platforms/Kconfig
+++ b/arch/powerpc/platforms/Kconfig
@@ -169,6 +169,16 @@ config CPU_FREQ_PMAC64
        help
          This adds support for frequency switching on Apple iMac G5,
          and some of the more recent desktop G5 machines as well.
+
+config PPC_PASEMI_CPUFREQ
+       bool "Support for PA Semi PWRficient"
+       depends on CPU_FREQ && PPC_PASEMI
+       default y
+       select CPU_FREQ_TABLE
+       help
+         This adds the support for frequency switching on PA Semi
+         PWRficient processors.
+
 endmenu
 
 config PPC601_SYNC_FIX
diff --git a/arch/powerpc/platforms/pasemi/Makefile 
b/arch/powerpc/platforms/pasemi/Makefile
index 7ffd43b..2cd2a4f 100644
--- a/arch/powerpc/platforms/pasemi/Makefile
+++ b/arch/powerpc/platforms/pasemi/Makefile
@@ -1,2 +1,3 @@
 obj-y  += setup.o pci.o time.o idle.o powersave.o iommu.o
 obj-$(CONFIG_PPC_PASEMI_MDIO)  += gpio_mdio.o
+obj-$(CONFIG_PPC_PASEMI_CPUFREQ) += cpufreq.o
diff --git a/arch/powerpc/platforms/pasemi/cpufreq.c 
b/arch/powerpc/platforms/pasemi/cpufreq.c
new file mode 100644
index 0000000..4dd5c51
--- /dev/null
+++ b/arch/powerpc/platforms/pasemi/cpufreq.c
@@ -0,0 +1,307 @@
+/*
+ * Copyright (C) 2007 PA Semi, Inc
+ *
+ * Authors: Egor Martovetsky <[EMAIL PROTECTED]>
+ *         Olof Johansson <[EMAIL PROTECTED]>
+ *
+ * Maintained by: Olof Johansson <[EMAIL PROTECTED]>
+ *
+ * Based on arch/powerpc/platforms/cell/cbe_cpufreq.c:
+ * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
+ *
+ * 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, 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/cpufreq.h>
+#include <linux/timer.h>
+
+#include <asm/hw_irq.h>
+#include <asm/io.h>
+#include <asm/prom.h>
+
+#define SDCASR_REG             0x0100
+#define SDCASR_REG_STRIDE      0x1000
+#define SDCPWR_CFGA0_REG       0x0100
+#define SDCPWR_PWST0_REG       0x0000
+#define SDCPWR_GIZTIME_REG     0x0440
+
+/* SDCPWR_GIZTIME_REG fields */
+#define SDCPWR_GIZTIME_GR      0x80000000
+#define SDCPWR_GIZTIME_LONGLOCK        0x000000ff
+
+/* Offset of ASR registers from SDC base */
+#define SDCASR_OFFSET          0x120000
+
+static void __iomem *sdcpwr_mapbase;
+static void __iomem *sdcasr_mapbase;
+
+static DEFINE_MUTEX(pas_switch_mutex);
+
+/* Current astate, is used when waking up from power savings on
+ * one core, in case the other core has switched states during
+ * the idle time.
+ */
+static int current_astate;
+
+/* We support 5(A0-A4) power states excluding turbo(A5-A6) modes */
+static struct cpufreq_frequency_table pas_freqs[] = {
+       {0,     0},
+       {1,     0},
+       {2,     0},
+       {3,     0},
+       {4,     0},
+       {0,     CPUFREQ_TABLE_END},
+};
+
+static struct freq_attr *pas_cpu_freqs_attr[] = {
+       &cpufreq_freq_attr_scaling_available_freqs,
+       NULL,
+};
+
+/*
+ * hardware specific functions
+ */
+
+static int get_astate_freq(int astate)
+{
+       u32 ret;
+       ret = in_le32(sdcpwr_mapbase + SDCPWR_CFGA0_REG + (astate * 0x10));
+
+       return ret & 0x3f;
+}
+
+static int get_cur_astate(int cpu)
+{
+       u32 ret;
+
+       ret = in_le32(sdcpwr_mapbase + SDCPWR_PWST0_REG);
+       ret = (ret >> (cpu * 4)) & 0x7;
+
+       return ret;
+}
+
+static int get_gizmo_latency(void)
+{
+       u32 giztime, ret;
+
+       giztime = in_le32(sdcpwr_mapbase + SDCPWR_GIZTIME_REG);
+
+       /* just provide the upper bound */
+       if (giztime & SDCPWR_GIZTIME_GR)
+               ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 128000;
+       else
+               ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 1000;
+
+       return ret;
+}
+
+static void set_astate(int cpu, unsigned int astate)
+{
+       u64 flags;
+
+       /* Return if called before init has run */
+       if (unlikely(!sdcasr_mapbase))
+               return;
+
+       local_irq_save(flags);
+
+       out_le32(sdcasr_mapbase + SDCASR_REG + SDCASR_REG_STRIDE*cpu, astate);
+
+       local_irq_restore(flags);
+}
+
+void restore_astate(int cpu)
+{
+       set_astate(cpu, current_astate);
+}
+
+/*
+ * cpufreq functions
+ */
+
+static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy)
+{
+       u32 *max_freq;
+       int i, cur_astate;
+       struct resource res;
+       struct device_node *cpu, *dn;
+       int err = -ENODEV;
+
+       cpu = of_get_cpu_node(policy->cpu, NULL);
+
+       if (!cpu)
+               goto out;
+
+       dn = of_find_compatible_node(NULL, "sdc", "1682m-sdc");
+       if (!dn)
+               goto out;
+       err = of_address_to_resource(dn, 0, &res);
+       of_node_put(dn);
+       if (err)
+               goto out;
+       sdcasr_mapbase = ioremap(res.start + SDCASR_OFFSET, 0x2000);
+       if (!sdcasr_mapbase) {
+               err = -EINVAL;
+               goto out;
+       }
+
+       dn = of_find_compatible_node(NULL, "gizmo", "1682m-gizmo");
+       if (!dn) {
+               err = -ENODEV;
+               goto out_unmap_sdcasr;
+       }
+       err = of_address_to_resource(dn, 0, &res);
+       of_node_put(dn);
+       if (err)
+               goto out_unmap_sdcasr;
+       sdcpwr_mapbase = ioremap(res.start, 0x1000);
+       if (!sdcpwr_mapbase) {
+               err = -EINVAL;
+               goto out_unmap_sdcasr;
+       }
+
+       pr_debug("init cpufreq on CPU %d\n", policy->cpu);
+
+       max_freq = (u32*) get_property(cpu, "clock-frequency", NULL);
+       if (!max_freq) {
+               err = -EINVAL;
+               goto out_unmap_sdcpwr;
+       }
+
+       /* we need the freq in kHz */
+       *max_freq /= 1000;
+
+       pr_debug("max clock-frequency is at %u kHz\n", *max_freq);
+       pr_debug("initializing frequency table\n");
+
+       /* initialize frequency table */
+       for (i=0; pas_freqs[i].frequency!=CPUFREQ_TABLE_END; i++) {
+               pas_freqs[i].frequency = get_astate_freq(pas_freqs[i].index) * 
100000;
+               pr_debug("%d: %d\n", i, pas_freqs[i].frequency);
+       }
+
+       policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
+
+       policy->cpuinfo.transition_latency = get_gizmo_latency();
+
+       cur_astate = get_cur_astate(policy->cpu);
+       pr_debug("current astate is at %d\n",cur_astate);
+
+       policy->cur = pas_freqs[cur_astate].frequency;
+       policy->cpus = cpu_online_map;
+
+       cpufreq_frequency_table_get_attr(pas_freqs, policy->cpu);
+
+       /* this ensures that policy->cpuinfo_min and policy->cpuinfo_max
+        * are set correctly
+        */
+       return cpufreq_frequency_table_cpuinfo(policy, pas_freqs);
+
+out_unmap_sdcpwr:
+       iounmap(sdcpwr_mapbase);
+
+out_unmap_sdcasr:
+       iounmap(sdcasr_mapbase);
+out:
+       return err;
+}
+
+static int pas_cpufreq_cpu_exit(struct cpufreq_policy *policy)
+{
+       if (sdcasr_mapbase)
+               iounmap(sdcasr_mapbase);
+       if (sdcpwr_mapbase)
+               iounmap(sdcpwr_mapbase);
+
+       cpufreq_frequency_table_put_attr(policy->cpu);
+       return 0;
+}
+
+static int pas_cpufreq_verify(struct cpufreq_policy *policy)
+{
+       return cpufreq_frequency_table_verify(policy, pas_freqs);
+}
+
+static int pas_cpufreq_target(struct cpufreq_policy *policy,
+                             unsigned int target_freq,
+                             unsigned int relation)
+{
+       struct cpufreq_freqs freqs;
+       int pas_astate_new;
+       int i;
+
+       cpufreq_frequency_table_target(policy,
+                                      pas_freqs,
+                                      target_freq,
+                                      relation,
+                                      &pas_astate_new);
+
+       freqs.old = policy->cur;
+       freqs.new = pas_freqs[pas_astate_new].frequency;
+       freqs.cpu = policy->cpu;
+
+       mutex_lock(&pas_switch_mutex);
+       cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+
+       pr_debug("setting frequency for cpu %d to %d kHz, 1/%d of max 
frequency\n",
+                policy->cpu,
+                pas_freqs[pas_astate_new].frequency,
+                pas_freqs[pas_astate_new].index);
+
+       current_astate = pas_astate_new;
+
+       for_each_online_cpu(i)
+               set_astate(i, pas_astate_new);
+
+       cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+       mutex_unlock(&pas_switch_mutex);
+
+       return 0;
+}
+
+static struct cpufreq_driver pas_cpufreq_driver = {
+       .name           = "pas-cpufreq",
+       .owner          = THIS_MODULE,
+       .flags          = CPUFREQ_CONST_LOOPS,
+       .init           = pas_cpufreq_cpu_init,
+       .exit           = pas_cpufreq_cpu_exit,
+       .verify         = pas_cpufreq_verify,
+       .target         = pas_cpufreq_target,
+       .attr           = pas_cpu_freqs_attr,
+};
+
+/*
+ * module init and destoy
+ */
+
+static int __init pas_cpufreq_init(void)
+{
+       if (!machine_is_compatible("PA6T-1682M"))
+               return -ENODEV;
+
+       return cpufreq_register_driver(&pas_cpufreq_driver);
+}
+
+static void __exit pas_cpufreq_exit(void)
+{
+       cpufreq_unregister_driver(&pas_cpufreq_driver);
+}
+
+module_init(pas_cpufreq_init);
+module_exit(pas_cpufreq_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Egor Martovetsky <[EMAIL PROTECTED]>, Olof Johansson <[EMAIL 
PROTECTED]>");
diff --git a/arch/powerpc/platforms/pasemi/idle.c 
b/arch/powerpc/platforms/pasemi/idle.c
index 1ca3ff3..5985ce0 100644
--- a/arch/powerpc/platforms/pasemi/idle.c
+++ b/arch/powerpc/platforms/pasemi/idle.c
@@ -61,6 +61,10 @@ static int pasemi_system_reset_exception(struct pt_regs 
*regs)
                /* do system reset */
                return 0;
        }
+
+       /* Set higher astate since we come out of power savings at 0 */
+       restore_astate(hard_smp_processor_id());
+
        /* everything handled */
        regs->msr |= MSR_RI;
        return 1;
@@ -68,6 +72,11 @@ static int pasemi_system_reset_exception(struct pt_regs 
*regs)
 
 void __init pasemi_idle_init(void)
 {
+#ifndef CONFIG_PPC_PASEMI_CPUFREQ
+       printk(KERN_WARNING "No cpufreq driver, powersavings modes disabled\n");
+       current_mode = 0;
+#endif
+
        ppc_md.system_reset_exception = pasemi_system_reset_exception;
        ppc_md.power_save = modes[current_mode].entry;
        printk(KERN_INFO "Using PA6T idle loop (%s)\n", 
modes[current_mode].name);
diff --git a/arch/powerpc/platforms/pasemi/pasemi.h 
b/arch/powerpc/platforms/pasemi/pasemi.h
index 2d3927e..be84954 100644
--- a/arch/powerpc/platforms/pasemi/pasemi.h
+++ b/arch/powerpc/platforms/pasemi/pasemi.h
@@ -14,6 +14,14 @@ extern void __init pasemi_idle_init(void);
 extern void idle_spin(void);
 extern void idle_doze(void);
 
+/* Restore astate to last set */
+#ifdef CONFIG_PPC_PASEMI_CPUFREQ
+extern void restore_astate(int cpu);
+#else
+static inline void restore_astate(int cpu)
+{
+}
+#endif
 
 
 #endif /* _PASEMI_PASEMI_H */
-
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