1 files changed, 169 insertions, 0 deletions

diff --git a/drivers/cpufreq/db8500-cpufreq.c b/drivers/cpufreq/db8500-cpufreq.c
new file mode 100644
index 000000000000..d90456a809f9
--- /dev/null
+++ b/drivers/cpufreq/db8500-cpufreq.c
@@ -0,0 +1,169 @@
+/*
+ * Copyright (C) STMicroelectronics 2009
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * License Terms: GNU General Public License v2
+ * Author: Sundar Iyer <sundar.iyer@stericsson.com>
+ * Author: Martin Persson <martin.persson@stericsson.com>
+ * Author: Jonas Aaberg <jonas.aberg@stericsson.com>
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/cpufreq.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/mfd/db8500-prcmu.h>
+#include <mach/id.h>
+
+static struct cpufreq_frequency_table freq_table[] = {
+        [0] = {
+                .index = 0,
+                .frequency = 300000,
+        },
+        [1] = {
+                .index = 1,
+                .frequency = 600000,
+        },
+        [2] = {
+                /* Used for MAX_OPP, if available */
+                .index = 2,
+                .frequency = CPUFREQ_TABLE_END,
+        },
+        [3] = {
+                .index = 3,
+                .frequency = CPUFREQ_TABLE_END,
+        },
+};
+
+static enum arm_opp idx2opp[] = {
+        ARM_50_OPP,
+        ARM_100_OPP,
+        ARM_MAX_OPP
+};
+
+static struct freq_attr *db8500_cpufreq_attr[] = {
+        &cpufreq_freq_attr_scaling_available_freqs,
+        NULL,
+};
+
+static int db8500_cpufreq_verify_speed(struct cpufreq_policy *policy)
+{
+        return cpufreq_frequency_table_verify(policy, freq_table);
+}
+
+static int db8500_cpufreq_target(struct cpufreq_policy *policy,
+                                unsigned int target_freq,
+                                unsigned int relation)
+{
+        struct cpufreq_freqs freqs;
+        unsigned int idx;
+
+        /* scale the target frequency to one of the extremes supported */
+        if (target_freq < policy->cpuinfo.min_freq)
+                target_freq = policy->cpuinfo.min_freq;
+        if (target_freq > policy->cpuinfo.max_freq)
+                target_freq = policy->cpuinfo.max_freq;
+
+        /* Lookup the next frequency */
+        if (cpufreq_frequency_table_target
+            (policy, freq_table, target_freq, relation, &idx)) {
+                return -EINVAL;
+        }
+
+        freqs.old = policy->cur;
+        freqs.new = freq_table[idx].frequency;
+        freqs.cpu = policy->cpu;
+
+        if (freqs.old == freqs.new)
+                return 0;
+
+        /* pre-change notification */
+        cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+
+        /* request the PRCM unit for opp change */
+        if (prcmu_set_arm_opp(idx2opp[idx])) {
+                pr_err("db8500-cpufreq:  Failed to set OPP level\n");
+                return -EINVAL;
+        }
+
+        /* post change notification */
+        cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+
+        return 0;
+}
+
+static unsigned int db8500_cpufreq_getspeed(unsigned int cpu)
+{
+        int i;
+        /* request the prcm to get the current ARM opp */
+        for (i = 0; prcmu_get_arm_opp() != idx2opp[i]; i++)
+                ;
+        return freq_table[i].frequency;
+}
+
+static int __cpuinit db8500_cpufreq_init(struct cpufreq_policy *policy)
+{
+        int res;
+        int i;
+
+        BUILD_BUG_ON(ARRAY_SIZE(idx2opp) + 1 != ARRAY_SIZE(freq_table));
+
+        if (cpu_is_u8500v2() && !prcmu_is_u8400()) {
+                freq_table[0].frequency = 400000;
+                freq_table[1].frequency = 800000;
+                if (prcmu_has_arm_maxopp())
+                        freq_table[2].frequency = 1000000;
+        }
+
+        /* get policy fields based on the table */
+        res = cpufreq_frequency_table_cpuinfo(policy, freq_table);
+        if (!res)
+                cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
+        else {
+                pr_err("db8500-cpufreq : Failed to read policy table\n");
+                return res;
+        }
+
+        policy->min = policy->cpuinfo.min_freq;
+        policy->max = policy->cpuinfo.max_freq;
+        policy->cur = db8500_cpufreq_getspeed(policy->cpu);
+
+        for (i = 0; freq_table[i].frequency != policy->cur; i++)
+                ;
+
+        policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
+
+        /*
+         * FIXME : Need to take time measurement across the target()
+         *         function with no/some/all drivers in the notification
+         *         list.
+         */
+        policy->cpuinfo.transition_latency = 20 * 1000; /* in ns */
+
+        /* policy sharing between dual CPUs */
+        cpumask_copy(policy->cpus, &cpu_present_map);
+
+        policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
+
+        return 0;
+}
+
+static struct cpufreq_driver db8500_cpufreq_driver = {
+        .flags  = CPUFREQ_STICKY,
+        .verify = db8500_cpufreq_verify_speed,
+        .target = db8500_cpufreq_target,
+        .get    = db8500_cpufreq_getspeed,
+        .init   = db8500_cpufreq_init,
+        .name   = "DB8500",
+        .attr   = db8500_cpufreq_attr,
+};
+
+static int __init db8500_cpufreq_register(void)
+{
+        if (!cpu_is_u8500v20_or_later())
+                return -ENODEV;
+
+        pr_info("cpufreq for DB8500 started\n");
+        return cpufreq_register_driver(&db8500_cpufreq_driver);
+}
+device_initcall(db8500_cpufreq_register);