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Diffstat (limited to 'drivers/cpufreq/omap-cpufreq.c')
-rw-r--r--drivers/cpufreq/omap-cpufreq.c274
1 files changed, 274 insertions, 0 deletions
diff --git a/drivers/cpufreq/omap-cpufreq.c b/drivers/cpufreq/omap-cpufreq.c
new file mode 100644
index 000000000000..5d04c57aae30
--- /dev/null
+++ b/drivers/cpufreq/omap-cpufreq.c
@@ -0,0 +1,274 @@
+/*
+ * CPU frequency scaling for OMAP using OPP information
+ *
+ * Copyright (C) 2005 Nokia Corporation
+ * Written by Tony Lindgren <tony@atomide.com>
+ *
+ * Based on cpu-sa1110.c, Copyright (C) 2001 Russell King
+ *
+ * Copyright (C) 2007-2011 Texas Instruments, Inc.
+ * - OMAP3/4 support by Rajendra Nayak, Santosh Shilimkar
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/cpufreq.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/opp.h>
+#include <linux/cpu.h>
+#include <linux/module.h>
+
+#include <asm/system.h>
+#include <asm/smp_plat.h>
+#include <asm/cpu.h>
+
+#include <plat/clock.h>
+#include <plat/omap-pm.h>
+#include <plat/common.h>
+#include <plat/omap_device.h>
+
+#include <mach/hardware.h>
+
+#ifdef CONFIG_SMP
+struct lpj_info {
+ unsigned long ref;
+ unsigned int freq;
+};
+
+static DEFINE_PER_CPU(struct lpj_info, lpj_ref);
+static struct lpj_info global_lpj_ref;
+#endif
+
+static struct cpufreq_frequency_table *freq_table;
+static atomic_t freq_table_users = ATOMIC_INIT(0);
+static struct clk *mpu_clk;
+static char *mpu_clk_name;
+static struct device *mpu_dev;
+
+static int omap_verify_speed(struct cpufreq_policy *policy)
+{
+ if (!freq_table)
+ return -EINVAL;
+ return cpufreq_frequency_table_verify(policy, freq_table);
+}
+
+static unsigned int omap_getspeed(unsigned int cpu)
+{
+ unsigned long rate;
+
+ if (cpu >= NR_CPUS)
+ return 0;
+
+ rate = clk_get_rate(mpu_clk) / 1000;
+ return rate;
+}
+
+static int omap_target(struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ unsigned int relation)
+{
+ unsigned int i;
+ int ret = 0;
+ struct cpufreq_freqs freqs;
+
+ if (!freq_table) {
+ dev_err(mpu_dev, "%s: cpu%d: no freq table!\n", __func__,
+ policy->cpu);
+ return -EINVAL;
+ }
+
+ ret = cpufreq_frequency_table_target(policy, freq_table, target_freq,
+ relation, &i);
+ if (ret) {
+ dev_dbg(mpu_dev, "%s: cpu%d: no freq match for %d(ret=%d)\n",
+ __func__, policy->cpu, target_freq, ret);
+ return ret;
+ }
+ freqs.new = freq_table[i].frequency;
+ if (!freqs.new) {
+ dev_err(mpu_dev, "%s: cpu%d: no match for freq %d\n", __func__,
+ policy->cpu, target_freq);
+ return -EINVAL;
+ }
+
+ freqs.old = omap_getspeed(policy->cpu);
+ freqs.cpu = policy->cpu;
+
+ if (freqs.old == freqs.new && policy->cur == freqs.new)
+ return ret;
+
+ /* notifiers */
+ for_each_cpu(i, policy->cpus) {
+ freqs.cpu = i;
+ cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+ }
+
+#ifdef CONFIG_CPU_FREQ_DEBUG
+ pr_info("cpufreq-omap: transition: %u --> %u\n", freqs.old, freqs.new);
+#endif
+
+ ret = clk_set_rate(mpu_clk, freqs.new * 1000);
+ freqs.new = omap_getspeed(policy->cpu);
+
+#ifdef CONFIG_SMP
+ /*
+ * Note that loops_per_jiffy is not updated on SMP systems in
+ * cpufreq driver. So, update the per-CPU loops_per_jiffy value
+ * on frequency transition. We need to update all dependent CPUs.
+ */
+ for_each_cpu(i, policy->cpus) {
+ struct lpj_info *lpj = &per_cpu(lpj_ref, i);
+ if (!lpj->freq) {
+ lpj->ref = per_cpu(cpu_data, i).loops_per_jiffy;
+ lpj->freq = freqs.old;
+ }
+
+ per_cpu(cpu_data, i).loops_per_jiffy =
+ cpufreq_scale(lpj->ref, lpj->freq, freqs.new);
+ }
+
+ /* And don't forget to adjust the global one */
+ if (!global_lpj_ref.freq) {
+ global_lpj_ref.ref = loops_per_jiffy;
+ global_lpj_ref.freq = freqs.old;
+ }
+ loops_per_jiffy = cpufreq_scale(global_lpj_ref.ref, global_lpj_ref.freq,
+ freqs.new);
+#endif
+
+ /* notifiers */
+ for_each_cpu(i, policy->cpus) {
+ freqs.cpu = i;
+ cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+ }
+
+ return ret;
+}
+
+static inline void freq_table_free(void)
+{
+ if (atomic_dec_and_test(&freq_table_users))
+ opp_free_cpufreq_table(mpu_dev, &freq_table);
+}
+
+static int __cpuinit omap_cpu_init(struct cpufreq_policy *policy)
+{
+ int result = 0;
+
+ mpu_clk = clk_get(NULL, mpu_clk_name);
+ if (IS_ERR(mpu_clk))
+ return PTR_ERR(mpu_clk);
+
+ if (policy->cpu >= NR_CPUS) {
+ result = -EINVAL;
+ goto fail_ck;
+ }
+
+ policy->cur = policy->min = policy->max = omap_getspeed(policy->cpu);
+
+ if (atomic_inc_return(&freq_table_users) == 1)
+ result = opp_init_cpufreq_table(mpu_dev, &freq_table);
+
+ if (result) {
+ dev_err(mpu_dev, "%s: cpu%d: failed creating freq table[%d]\n",
+ __func__, policy->cpu, result);
+ goto fail_ck;
+ }
+
+ result = cpufreq_frequency_table_cpuinfo(policy, freq_table);
+ if (result)
+ goto fail_table;
+
+ cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
+
+ policy->min = policy->cpuinfo.min_freq;
+ policy->max = policy->cpuinfo.max_freq;
+ policy->cur = omap_getspeed(policy->cpu);
+
+ /*
+ * On OMAP SMP configuartion, both processors share the voltage
+ * and clock. So both CPUs needs to be scaled together and hence
+ * needs software co-ordination. Use cpufreq affected_cpus
+ * interface to handle this scenario. Additional is_smp() check
+ * is to keep SMP_ON_UP build working.
+ */
+ if (is_smp()) {
+ policy->shared_type = CPUFREQ_SHARED_TYPE_ANY;
+ cpumask_setall(policy->cpus);
+ }
+
+ /* FIXME: what's the actual transition time? */
+ policy->cpuinfo.transition_latency = 300 * 1000;
+
+ return 0;
+
+fail_table:
+ freq_table_free();
+fail_ck:
+ clk_put(mpu_clk);
+ return result;
+}
+
+static int omap_cpu_exit(struct cpufreq_policy *policy)
+{
+ freq_table_free();
+ clk_put(mpu_clk);
+ return 0;
+}
+
+static struct freq_attr *omap_cpufreq_attr[] = {
+ &cpufreq_freq_attr_scaling_available_freqs,
+ NULL,
+};
+
+static struct cpufreq_driver omap_driver = {
+ .flags = CPUFREQ_STICKY,
+ .verify = omap_verify_speed,
+ .target = omap_target,
+ .get = omap_getspeed,
+ .init = omap_cpu_init,
+ .exit = omap_cpu_exit,
+ .name = "omap",
+ .attr = omap_cpufreq_attr,
+};
+
+static int __init omap_cpufreq_init(void)
+{
+ if (cpu_is_omap24xx())
+ mpu_clk_name = "virt_prcm_set";
+ else if (cpu_is_omap34xx())
+ mpu_clk_name = "dpll1_ck";
+ else if (cpu_is_omap44xx())
+ mpu_clk_name = "dpll_mpu_ck";
+
+ if (!mpu_clk_name) {
+ pr_err("%s: unsupported Silicon?\n", __func__);
+ return -EINVAL;
+ }
+
+ mpu_dev = omap_device_get_by_hwmod_name("mpu");
+ if (!mpu_dev) {
+ pr_warning("%s: unable to get the mpu device\n", __func__);
+ return -EINVAL;
+ }
+
+ return cpufreq_register_driver(&omap_driver);
+}
+
+static void __exit omap_cpufreq_exit(void)
+{
+ cpufreq_unregister_driver(&omap_driver);
+}
+
+MODULE_DESCRIPTION("cpufreq driver for OMAP SoCs");
+MODULE_LICENSE("GPL");
+module_init(omap_cpufreq_init);
+module_exit(omap_cpufreq_exit);