cpufreq: ia64: move cpufreq driver to drivers/cpufreq

This patch moves cpufreq driver of IA64 architecture to drivers/cpufreq.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

3 files changed, 456 insertions, 0 deletions

diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
index d7ce6ccf5c91..a2f1600c78f8 100644
--- a/drivers/cpufreq/Kconfig
+++ b/drivers/cpufreq/Kconfig
@@ -218,6 +218,23 @@ config AVR32_AT32AP_CPUFREQ
 
 endmenu
 
+menu "CPUFreq processor drivers"
+depends on IA64
+
+config IA64_ACPI_CPUFREQ
+        tristate "ACPI Processor P-States driver"
+        select CPU_FREQ_TABLE
+        depends on ACPI_PROCESSOR
+        help
+        This driver adds a CPUFreq driver which utilizes the ACPI
+        Processor Performance States.
+
+        For details, take a look at <file:Documentation/cpu-freq/>.
+
+        If in doubt, say N.
+
+endmenu
+
 menu "PowerPC CPU frequency scaling drivers"
 depends on PPC32 || PPC64
 source "drivers/cpufreq/Kconfig.powerpc"
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index 2d6dbf30862b..ab681337e6d4 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -81,3 +81,4 @@ obj-$(CONFIG_AVR32_AT32AP_CPUFREQ)	+= at32ap-cpufreq.o
 obj-$(CONFIG_BLACKFIN)                  += blackfin-cpufreq.o
 obj-$(CONFIG_CRIS_MACH_ARTPEC3)         += cris-artpec3-cpufreq.o
 obj-$(CONFIG_ETRAXFS)                   += cris-etraxfs-cpufreq.o
+obj-$(CONFIG_IA64_ACPI_CPUFREQ)         += ia64-acpi-cpufreq.o
diff --git a/drivers/cpufreq/ia64-acpi-cpufreq.c b/drivers/cpufreq/ia64-acpi-cpufreq.c
new file mode 100644
index 000000000000..c0075dbaa633
--- /dev/null
+++ b/drivers/cpufreq/ia64-acpi-cpufreq.c
@@ -0,0 +1,438 @@
+/*
+ * This file provides the ACPI based P-state support. This
+ * module works with generic cpufreq infrastructure. Most of
+ * the code is based on i386 version
+ * (arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c)
+ *
+ * Copyright (C) 2005 Intel Corp
+ *      Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/cpufreq.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/pal.h>
+
+#include <linux/acpi.h>
+#include <acpi/processor.h>
+
+MODULE_AUTHOR("Venkatesh Pallipadi");
+MODULE_DESCRIPTION("ACPI Processor P-States Driver");
+MODULE_LICENSE("GPL");
+
+
+struct cpufreq_acpi_io {
+        struct acpi_processor_performance       acpi_data;
+        struct cpufreq_frequency_table          *freq_table;
+        unsigned int                            resume;
+};
+
+static struct cpufreq_acpi_io   *acpi_io_data[NR_CPUS];
+
+static struct cpufreq_driver acpi_cpufreq_driver;
+
+
+static int
+processor_set_pstate (
+        u32     value)
+{
+        s64 retval;
+
+        pr_debug("processor_set_pstate\n");
+
+        retval = ia64_pal_set_pstate((u64)value);
+
+        if (retval) {
+                pr_debug("Failed to set freq to 0x%x, with error 0x%lx\n",
+                        value, retval);
+                return -ENODEV;
+        }
+        return (int)retval;
+}
+
+
+static int
+processor_get_pstate (
+        u32     *value)
+{
+        u64     pstate_index = 0;
+        s64     retval;
+
+        pr_debug("processor_get_pstate\n");
+
+        retval = ia64_pal_get_pstate(&pstate_index,
+                                     PAL_GET_PSTATE_TYPE_INSTANT);
+        *value = (u32) pstate_index;
+
+        if (retval)
+                pr_debug("Failed to get current freq with "
+                        "error 0x%lx, idx 0x%x\n", retval, *value);
+
+        return (int)retval;
+}
+
+
+/* To be used only after data->acpi_data is initialized */
+static unsigned
+extract_clock (
+        struct cpufreq_acpi_io *data,
+        unsigned value,
+        unsigned int cpu)
+{
+        unsigned long i;
+
+        pr_debug("extract_clock\n");
+
+        for (i = 0; i < data->acpi_data.state_count; i++) {
+                if (value == data->acpi_data.states[i].status)
+                        return data->acpi_data.states[i].core_frequency;
+        }
+        return data->acpi_data.states[i-1].core_frequency;
+}
+
+
+static unsigned int
+processor_get_freq (
+        struct cpufreq_acpi_io  *data,
+        unsigned int            cpu)
+{
+        int                     ret = 0;
+        u32                     value = 0;
+        cpumask_t               saved_mask;
+        unsigned long           clock_freq;
+
+        pr_debug("processor_get_freq\n");
+
+        saved_mask = current->cpus_allowed;
+        set_cpus_allowed_ptr(current, cpumask_of(cpu));
+        if (smp_processor_id() != cpu)
+                goto migrate_end;
+
+        /* processor_get_pstate gets the instantaneous frequency */
+        ret = processor_get_pstate(&value);
+
+        if (ret) {
+                set_cpus_allowed_ptr(current, &saved_mask);
+                printk(KERN_WARNING "get performance failed with error %d\n",
+                       ret);
+                ret = 0;
+                goto migrate_end;
+        }
+        clock_freq = extract_clock(data, value, cpu);
+        ret = (clock_freq*1000);
+
+migrate_end:
+        set_cpus_allowed_ptr(current, &saved_mask);
+        return ret;
+}
+
+
+static int
+processor_set_freq (
+        struct cpufreq_acpi_io  *data,
+        struct cpufreq_policy   *policy,
+        int                     state)
+{
+        int                     ret = 0;
+        u32                     value = 0;
+        struct cpufreq_freqs    cpufreq_freqs;
+        cpumask_t               saved_mask;
+        int                     retval;
+
+        pr_debug("processor_set_freq\n");
+
+        saved_mask = current->cpus_allowed;
+        set_cpus_allowed_ptr(current, cpumask_of(policy->cpu));
+        if (smp_processor_id() != policy->cpu) {
+                retval = -EAGAIN;
+                goto migrate_end;
+        }
+
+        if (state == data->acpi_data.state) {
+                if (unlikely(data->resume)) {
+                        pr_debug("Called after resume, resetting to P%d\n", state);
+                        data->resume = 0;
+                } else {
+                        pr_debug("Already at target state (P%d)\n", state);
+                        retval = 0;
+                        goto migrate_end;
+                }
+        }
+
+        pr_debug("Transitioning from P%d to P%d\n",
+                data->acpi_data.state, state);
+
+        /* cpufreq frequency struct */
+        cpufreq_freqs.old = data->freq_table[data->acpi_data.state].frequency;
+        cpufreq_freqs.new = data->freq_table[state].frequency;
+
+        /* notify cpufreq */
+        cpufreq_notify_transition(policy, &cpufreq_freqs, CPUFREQ_PRECHANGE);
+
+        /*
+         * First we write the target state's 'control' value to the
+         * control_register.
+         */
+
+        value = (u32) data->acpi_data.states[state].control;
+
+        pr_debug("Transitioning to state: 0x%08x\n", value);
+
+        ret = processor_set_pstate(value);
+        if (ret) {
+                unsigned int tmp = cpufreq_freqs.new;
+                cpufreq_notify_transition(policy, &cpufreq_freqs,
+                                CPUFREQ_POSTCHANGE);
+                cpufreq_freqs.new = cpufreq_freqs.old;
+                cpufreq_freqs.old = tmp;
+                cpufreq_notify_transition(policy, &cpufreq_freqs,
+                                CPUFREQ_PRECHANGE);
+                cpufreq_notify_transition(policy, &cpufreq_freqs,
+                                CPUFREQ_POSTCHANGE);
+                printk(KERN_WARNING "Transition failed with error %d\n", ret);
+                retval = -ENODEV;
+                goto migrate_end;
+        }
+
+        cpufreq_notify_transition(policy, &cpufreq_freqs, CPUFREQ_POSTCHANGE);
+
+        data->acpi_data.state = state;
+
+        retval = 0;
+
+migrate_end:
+        set_cpus_allowed_ptr(current, &saved_mask);
+        return (retval);
+}
+
+
+static unsigned int
+acpi_cpufreq_get (
+        unsigned int            cpu)
+{
+        struct cpufreq_acpi_io *data = acpi_io_data[cpu];
+
+        pr_debug("acpi_cpufreq_get\n");
+
+        return processor_get_freq(data, cpu);
+}
+
+
+static int
+acpi_cpufreq_target (
+        struct cpufreq_policy   *policy,
+        unsigned int target_freq,
+        unsigned int relation)
+{
+        struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
+        unsigned int next_state = 0;
+        unsigned int result = 0;
+
+        pr_debug("acpi_cpufreq_setpolicy\n");
+
+        result = cpufreq_frequency_table_target(policy,
+                        data->freq_table, target_freq, relation, &next_state);
+        if (result)
+                return (result);
+
+        result = processor_set_freq(data, policy, next_state);
+
+        return (result);
+}
+
+
+static int
+acpi_cpufreq_verify (
+        struct cpufreq_policy   *policy)
+{
+        unsigned int result = 0;
+        struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
+
+        pr_debug("acpi_cpufreq_verify\n");
+
+        result = cpufreq_frequency_table_verify(policy,
+                        data->freq_table);
+
+        return (result);
+}
+
+
+static int
+acpi_cpufreq_cpu_init (
+        struct cpufreq_policy   *policy)
+{
+        unsigned int            i;
+        unsigned int            cpu = policy->cpu;
+        struct cpufreq_acpi_io  *data;
+        unsigned int            result = 0;
+
+        pr_debug("acpi_cpufreq_cpu_init\n");
+
+        data = kzalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL);
+        if (!data)
+                return (-ENOMEM);
+
+        acpi_io_data[cpu] = data;
+
+        result = acpi_processor_register_performance(&data->acpi_data, cpu);
+
+        if (result)
+                goto err_free;
+
+        /* capability check */
+        if (data->acpi_data.state_count <= 1) {
+                pr_debug("No P-States\n");
+                result = -ENODEV;
+                goto err_unreg;
+        }
+
+        if ((data->acpi_data.control_register.space_id !=
+                                        ACPI_ADR_SPACE_FIXED_HARDWARE) ||
+            (data->acpi_data.status_register.space_id !=
+                                        ACPI_ADR_SPACE_FIXED_HARDWARE)) {
+                pr_debug("Unsupported address space [%d, %d]\n",
+                        (u32) (data->acpi_data.control_register.space_id),
+                        (u32) (data->acpi_data.status_register.space_id));
+                result = -ENODEV;
+                goto err_unreg;
+        }
+
+        /* alloc freq_table */
+        data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
+                                   (data->acpi_data.state_count + 1),
+                                   GFP_KERNEL);
+        if (!data->freq_table) {
+                result = -ENOMEM;
+                goto err_unreg;
+        }
+
+        /* detect transition latency */
+        policy->cpuinfo.transition_latency = 0;
+        for (i=0; i<data->acpi_data.state_count; i++) {
+                if ((data->acpi_data.states[i].transition_latency * 1000) >
+                    policy->cpuinfo.transition_latency) {
+                        policy->cpuinfo.transition_latency =
+                            data->acpi_data.states[i].transition_latency * 1000;
+                }
+        }
+        policy->cur = processor_get_freq(data, policy->cpu);
+
+        /* table init */
+        for (i = 0; i <= data->acpi_data.state_count; i++)
+        {
+                data->freq_table[i].index = i;
+                if (i < data->acpi_data.state_count) {
+                        data->freq_table[i].frequency =
+                              data->acpi_data.states[i].core_frequency * 1000;
+                } else {
+                        data->freq_table[i].frequency = CPUFREQ_TABLE_END;
+                }
+        }
+
+        result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
+        if (result) {
+                goto err_freqfree;
+        }
+
+        /* notify BIOS that we exist */
+        acpi_processor_notify_smm(THIS_MODULE);
+
+        printk(KERN_INFO "acpi-cpufreq: CPU%u - ACPI performance management "
+               "activated.\n", cpu);
+
+        for (i = 0; i < data->acpi_data.state_count; i++)
+                pr_debug("     %cP%d: %d MHz, %d mW, %d uS, %d uS, 0x%x 0x%x\n",
+                        (i == data->acpi_data.state?'*':' '), i,
+                        (u32) data->acpi_data.states[i].core_frequency,
+                        (u32) data->acpi_data.states[i].power,
+                        (u32) data->acpi_data.states[i].transition_latency,
+                        (u32) data->acpi_data.states[i].bus_master_latency,
+                        (u32) data->acpi_data.states[i].status,
+                        (u32) data->acpi_data.states[i].control);
+
+        cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
+
+        /* the first call to ->target() should result in us actually
+         * writing something to the appropriate registers. */
+        data->resume = 1;
+
+        return (result);
+
+ err_freqfree:
+        kfree(data->freq_table);
+ err_unreg:
+        acpi_processor_unregister_performance(&data->acpi_data, cpu);
+ err_free:
+        kfree(data);
+        acpi_io_data[cpu] = NULL;
+
+        return (result);
+}
+
+
+static int
+acpi_cpufreq_cpu_exit (
+        struct cpufreq_policy   *policy)
+{
+        struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
+
+        pr_debug("acpi_cpufreq_cpu_exit\n");
+
+        if (data) {
+                cpufreq_frequency_table_put_attr(policy->cpu);
+                acpi_io_data[policy->cpu] = NULL;
+                acpi_processor_unregister_performance(&data->acpi_data,
+                                                      policy->cpu);
+                kfree(data);
+        }
+
+        return (0);
+}
+
+
+static struct freq_attr* acpi_cpufreq_attr[] = {
+        &cpufreq_freq_attr_scaling_available_freqs,
+        NULL,
+};
+
+
+static struct cpufreq_driver acpi_cpufreq_driver = {
+        .verify         = acpi_cpufreq_verify,
+        .target         = acpi_cpufreq_target,
+        .get            = acpi_cpufreq_get,
+        .init           = acpi_cpufreq_cpu_init,
+        .exit           = acpi_cpufreq_cpu_exit,
+        .name           = "acpi-cpufreq",
+        .owner          = THIS_MODULE,
+        .attr           = acpi_cpufreq_attr,
+};
+
+
+static int __init
+acpi_cpufreq_init (void)
+{
+        pr_debug("acpi_cpufreq_init\n");
+
+        return cpufreq_register_driver(&acpi_cpufreq_driver);
+}
+
+
+static void __exit
+acpi_cpufreq_exit (void)
+{
+        pr_debug("acpi_cpufreq_exit\n");
+
+        cpufreq_unregister_driver(&acpi_cpufreq_driver);
+        return;
+}
+
+
+late_initcall(acpi_cpufreq_init);
+module_exit(acpi_cpufreq_exit);
+