4 files changed, 439 insertions, 0 deletions

diff --git a/arch/mips/kernel/cpufreq/Kconfig b/arch/mips/kernel/cpufreq/Kconfig
new file mode 100644
index 000000000000..58c601eee6fd
--- /dev/null
+++ b/arch/mips/kernel/cpufreq/Kconfig
@@ -0,0 +1,41 @@
+#
+# CPU Frequency scaling
+#
+
+config MIPS_EXTERNAL_TIMER
+	bool
+
+config MIPS_CPUFREQ
+	bool
+	default y
+	depends on CPU_SUPPORTS_CPUFREQ && MIPS_EXTERNAL_TIMER
+
+if MIPS_CPUFREQ
+
+menu "CPU Frequency scaling"
+
+source "drivers/cpufreq/Kconfig"
+
+if CPU_FREQ
+
+comment "CPUFreq processor drivers"
+
+config LOONGSON2_CPUFREQ
+	tristate "Loongson2 CPUFreq Driver"
+	select CPU_FREQ_TABLE
+	depends on MIPS_CPUFREQ
+	help
+	  This option adds a CPUFreq driver for loongson processors which
+	  support software configurable cpu frequency.
+
+	  Loongson2F and it's successors support this feature.
+
+	  For details, take a look at <file:Documentation/cpu-freq/>.
+
+	  If in doubt, say N.
+
+endif	# CPU_FREQ
+
+endmenu
+
+endif	# MIPS_CPUFREQ
diff --git a/arch/mips/kernel/cpufreq/Makefile b/arch/mips/kernel/cpufreq/Makefile
new file mode 100644
index 000000000000..c3479a432efe
--- /dev/null
+++ b/arch/mips/kernel/cpufreq/Makefile
@@ -0,0 +1,5 @@
+#
+# Makefile for the Linux/MIPS cpufreq.
+#
+
+obj-$(CONFIG_LOONGSON2_CPUFREQ) += loongson2_cpufreq.o loongson2_clock.o
diff --git a/arch/mips/kernel/cpufreq/loongson2_clock.c b/arch/mips/kernel/cpufreq/loongson2_clock.c
new file mode 100644
index 000000000000..d7ca256e33ef
--- /dev/null
+++ b/arch/mips/kernel/cpufreq/loongson2_clock.c
@@ -0,0 +1,166 @@
+/*
+ * Copyright (C) 2006 - 2008 Lemote Inc. & Insititute of Computing Technology
+ * Author: Yanhua, yanh@lemote.com
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/cpufreq.h>
+#include <linux/platform_device.h>
+
+#include <asm/clock.h>
+
+#include <loongson.h>
+
+static LIST_HEAD(clock_list);
+static DEFINE_SPINLOCK(clock_lock);
+static DEFINE_MUTEX(clock_list_sem);
+
+/* Minimum CLK support */
+enum {
+	DC_ZERO, DC_25PT = 2, DC_37PT, DC_50PT, DC_62PT, DC_75PT,
+	DC_87PT, DC_DISABLE, DC_RESV
+};
+
+struct cpufreq_frequency_table loongson2_clockmod_table[] = {
+	{DC_RESV, CPUFREQ_ENTRY_INVALID},
+	{DC_ZERO, CPUFREQ_ENTRY_INVALID},
+	{DC_25PT, 0},
+	{DC_37PT, 0},
+	{DC_50PT, 0},
+	{DC_62PT, 0},
+	{DC_75PT, 0},
+	{DC_87PT, 0},
+	{DC_DISABLE, 0},
+	{DC_RESV, CPUFREQ_TABLE_END},
+};
+EXPORT_SYMBOL_GPL(loongson2_clockmod_table);
+
+static struct clk cpu_clk = {
+	.name = "cpu_clk",
+	.flags = CLK_ALWAYS_ENABLED | CLK_RATE_PROPAGATES,
+	.rate = 800000000,
+};
+
+struct clk *clk_get(struct device *dev, const char *id)
+{
+	return &cpu_clk;
+}
+EXPORT_SYMBOL(clk_get);
+
+static void propagate_rate(struct clk *clk)
+{
+	struct clk *clkp;
+
+	list_for_each_entry(clkp, &clock_list, node) {
+		if (likely(clkp->parent != clk))
+			continue;
+		if (likely(clkp->ops && clkp->ops->recalc))
+			clkp->ops->recalc(clkp);
+		if (unlikely(clkp->flags & CLK_RATE_PROPAGATES))
+			propagate_rate(clkp);
+	}
+}
+
+int clk_enable(struct clk *clk)
+{
+	return 0;
+}
+EXPORT_SYMBOL(clk_enable);
+
+void clk_disable(struct clk *clk)
+{
+}
+EXPORT_SYMBOL(clk_disable);
+
+unsigned long clk_get_rate(struct clk *clk)
+{
+	return (unsigned long)clk->rate;
+}
+EXPORT_SYMBOL(clk_get_rate);
+
+void clk_put(struct clk *clk)
+{
+}
+EXPORT_SYMBOL(clk_put);
+
+int clk_set_rate(struct clk *clk, unsigned long rate)
+{
+	return clk_set_rate_ex(clk, rate, 0);
+}
+EXPORT_SYMBOL_GPL(clk_set_rate);
+
+int clk_set_rate_ex(struct clk *clk, unsigned long rate, int algo_id)
+{
+	int ret = 0;
+	int regval;
+	int i;
+
+	if (likely(clk->ops && clk->ops->set_rate)) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&clock_lock, flags);
+		ret = clk->ops->set_rate(clk, rate, algo_id);
+		spin_unlock_irqrestore(&clock_lock, flags);
+	}
+
+	if (unlikely(clk->flags & CLK_RATE_PROPAGATES))
+		propagate_rate(clk);
+
+	for (i = 0; loongson2_clockmod_table[i].frequency != CPUFREQ_TABLE_END;
+	     i++) {
+		if (loongson2_clockmod_table[i].frequency ==
+		    CPUFREQ_ENTRY_INVALID)
+			continue;
+		if (rate == loongson2_clockmod_table[i].frequency)
+			break;
+	}
+	if (rate != loongson2_clockmod_table[i].frequency)
+		return -ENOTSUPP;
+
+	clk->rate = rate;
+
+	regval = LOONGSON_CHIPCFG0;
+	regval = (regval & ~0x7) | (loongson2_clockmod_table[i].index - 1);
+	LOONGSON_CHIPCFG0 = regval;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(clk_set_rate_ex);
+
+long clk_round_rate(struct clk *clk, unsigned long rate)
+{
+	if (likely(clk->ops && clk->ops->round_rate)) {
+		unsigned long flags, rounded;
+
+		spin_lock_irqsave(&clock_lock, flags);
+		rounded = clk->ops->round_rate(clk, rate);
+		spin_unlock_irqrestore(&clock_lock, flags);
+
+		return rounded;
+	}
+
+	return rate;
+}
+EXPORT_SYMBOL_GPL(clk_round_rate);
+
+/*
+ * This is the simple version of Loongson-2 wait, Maybe we need do this in
+ * interrupt disabled content
+ */
+
+DEFINE_SPINLOCK(loongson2_wait_lock);
+void loongson2_cpu_wait(void)
+{
+	u32 cpu_freq;
+	unsigned long flags;
+
+	spin_lock_irqsave(&loongson2_wait_lock, flags);
+	cpu_freq = LOONGSON_CHIPCFG0;
+	LOONGSON_CHIPCFG0 &= ~0x7;	/* Put CPU into wait mode */
+	LOONGSON_CHIPCFG0 = cpu_freq;	/* Restore CPU state */
+	spin_unlock_irqrestore(&loongson2_wait_lock, flags);
+}
+EXPORT_SYMBOL_GPL(loongson2_cpu_wait);
diff --git a/arch/mips/kernel/cpufreq/loongson2_cpufreq.c b/arch/mips/kernel/cpufreq/loongson2_cpufreq.c
new file mode 100644
index 000000000000..2f6a0b147ab8
--- /dev/null
+++ b/arch/mips/kernel/cpufreq/loongson2_cpufreq.c
@@ -0,0 +1,227 @@
+/*
+ * Cpufreq driver for the loongson-2 processors
+ *
+ * The 2E revision of loongson processor not support this feature.
+ *
+ * Copyright (C) 2006 - 2008 Lemote Inc. & Insititute of Computing Technology
+ * Author: Yanhua, yanh@lemote.com
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/cpufreq.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/sched.h>	/* set_cpus_allowed() */
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+
+#include <asm/clock.h>
+
+#include <loongson.h>
+
+static uint nowait;
+
+static struct clk *cpuclk;
+
+static void (*saved_cpu_wait) (void);
+
+static int loongson2_cpu_freq_notifier(struct notifier_block *nb,
+					unsigned long val, void *data);
+
+static struct notifier_block loongson2_cpufreq_notifier_block = {
+	.notifier_call = loongson2_cpu_freq_notifier
+};
+
+static int loongson2_cpu_freq_notifier(struct notifier_block *nb,
+					unsigned long val, void *data)
+{
+	if (val == CPUFREQ_POSTCHANGE)
+		current_cpu_data.udelay_val = loops_per_jiffy;
+
+	return 0;
+}
+
+static unsigned int loongson2_cpufreq_get(unsigned int cpu)
+{
+	return clk_get_rate(cpuclk);
+}
+
+/*
+ * Here we notify other drivers of the proposed change and the final change.
+ */
+static int loongson2_cpufreq_target(struct cpufreq_policy *policy,
+				     unsigned int target_freq,
+				     unsigned int relation)
+{
+	unsigned int cpu = policy->cpu;
+	unsigned int newstate = 0;
+	cpumask_t cpus_allowed;
+	struct cpufreq_freqs freqs;
+	unsigned int freq;
+
+	if (!cpu_online(cpu))
+		return -ENODEV;
+
+	cpus_allowed = current->cpus_allowed;
+	set_cpus_allowed(current, cpumask_of_cpu(cpu));
+
+	if (cpufreq_frequency_table_target
+	    (policy, &loongson2_clockmod_table[0], target_freq, relation,
+	     &newstate))
+		return -EINVAL;
+
+	freq =
+	    ((cpu_clock_freq / 1000) *
+	     loongson2_clockmod_table[newstate].index) / 8;
+	if (freq < policy->min || freq > policy->max)
+		return -EINVAL;
+
+	pr_debug("cpufreq: requested frequency %u Hz\n", target_freq * 1000);
+
+	freqs.cpu = cpu;
+	freqs.old = loongson2_cpufreq_get(cpu);
+	freqs.new = freq;
+	freqs.flags = 0;
+
+	if (freqs.new == freqs.old)
+		return 0;
+
+	/* notifiers */
+	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+
+	set_cpus_allowed(current, cpus_allowed);
+
+	/* setting the cpu frequency */
+	clk_set_rate(cpuclk, freq);
+
+	/* notifiers */
+	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+
+	pr_debug("cpufreq: set frequency %u kHz\n", freq);
+
+	return 0;
+}
+
+static int loongson2_cpufreq_cpu_init(struct cpufreq_policy *policy)
+{
+	int i;
+
+	if (!cpu_online(policy->cpu))
+		return -ENODEV;
+
+	cpuclk = clk_get(NULL, "cpu_clk");
+	if (IS_ERR(cpuclk)) {
+		printk(KERN_ERR "cpufreq: couldn't get CPU clk\n");
+		return PTR_ERR(cpuclk);
+	}
+
+	cpuclk->rate = cpu_clock_freq / 1000;
+	if (!cpuclk->rate)
+		return -EINVAL;
+
+	/* clock table init */
+	for (i = 2;
+	     (loongson2_clockmod_table[i].frequency != CPUFREQ_TABLE_END);
+	     i++)
+		loongson2_clockmod_table[i].frequency = (cpuclk->rate * i) / 8;
+
+	policy->cur = loongson2_cpufreq_get(policy->cpu);
+
+	cpufreq_frequency_table_get_attr(&loongson2_clockmod_table[0],
+					 policy->cpu);
+
+	return cpufreq_frequency_table_cpuinfo(policy,
+					    &loongson2_clockmod_table[0]);
+}
+
+static int loongson2_cpufreq_verify(struct cpufreq_policy *policy)
+{
+	return cpufreq_frequency_table_verify(policy,
+					      &loongson2_clockmod_table[0]);
+}
+
+static int loongson2_cpufreq_exit(struct cpufreq_policy *policy)
+{
+	clk_put(cpuclk);
+	return 0;
+}
+
+static struct freq_attr *loongson2_table_attr[] = {
+	&cpufreq_freq_attr_scaling_available_freqs,
+	NULL,
+};
+
+static struct cpufreq_driver loongson2_cpufreq_driver = {
+	.owner = THIS_MODULE,
+	.name = "loongson2",
+	.init = loongson2_cpufreq_cpu_init,
+	.verify = loongson2_cpufreq_verify,
+	.target = loongson2_cpufreq_target,
+	.get = loongson2_cpufreq_get,
+	.exit = loongson2_cpufreq_exit,
+	.attr = loongson2_table_attr,
+};
+
+static struct platform_device_id platform_device_ids[] = {
+	{
+		.name = "loongson2_cpufreq",
+	},
+	{}
+};
+
+MODULE_DEVICE_TABLE(platform, platform_device_ids);
+
+static struct platform_driver platform_driver = {
+	.driver = {
+		.name = "loongson2_cpufreq",
+		.owner = THIS_MODULE,
+	},
+	.id_table = platform_device_ids,
+};
+
+static int __init cpufreq_init(void)
+{
+	int ret;
+
+	/* Register platform stuff */
+	ret = platform_driver_register(&platform_driver);
+	if (ret)
+		return ret;
+
+	pr_info("cpufreq: Loongson-2F CPU frequency driver.\n");
+
+	cpufreq_register_notifier(&loongson2_cpufreq_notifier_block,
+				  CPUFREQ_TRANSITION_NOTIFIER);
+
+	ret = cpufreq_register_driver(&loongson2_cpufreq_driver);
+
+	if (!ret && !nowait) {
+		saved_cpu_wait = cpu_wait;
+		cpu_wait = loongson2_cpu_wait;
+	}
+
+	return ret;
+}
+
+static void __exit cpufreq_exit(void)
+{
+	if (!nowait && saved_cpu_wait)
+		cpu_wait = saved_cpu_wait;
+	cpufreq_unregister_driver(&loongson2_cpufreq_driver);
+	cpufreq_unregister_notifier(&loongson2_cpufreq_notifier_block,
+				    CPUFREQ_TRANSITION_NOTIFIER);
+
+	platform_driver_unregister(&platform_driver);
+}
+
+module_init(cpufreq_init);
+module_exit(cpufreq_exit);
+
+module_param(nowait, uint, 0644);
+MODULE_PARM_DESC(nowait, "Disable Loongson-2F specific wait");
+
+MODULE_AUTHOR("Yanhua <yanh@lemote.com>");
+MODULE_DESCRIPTION("cpufreq driver for Loongson2F");
+MODULE_LICENSE("GPL");