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);