Initial import

1 files changed, 181 insertions, 0 deletions

diff --git a/drivers/cpufreq/davinci-cpufreq.c b/drivers/cpufreq/davinci-cpufreq.c
new file mode 100644
index 000000000..7e336d20c
--- /dev/null
+++ b/drivers/cpufreq/davinci-cpufreq.c
@@ -0,0 +1,181 @@
+/*
+ * CPU frequency scaling for DaVinci
+ *
+ * Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/
+ *
+ * Based on linux/arch/arm/plat-omap/cpu-omap.c. Original Copyright follows:
+ *
+ *  Copyright (C) 2005 Nokia Corporation
+ *  Written by Tony Lindgren <tony@atomide.com>
+ *
+ *  Based on cpu-sa1110.c, Copyright (C) 2001 Russell King
+ *
+ * Copyright (C) 2007-2008 Texas Instruments, Inc.
+ * Updated to support OMAP3
+ * Rajendra Nayak <rnayak@ti.com>
+ *
+ * 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/cpufreq.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+#include <linux/export.h>
+
+#include <mach/hardware.h>
+#include <mach/cpufreq.h>
+#include <mach/common.h>
+
+struct davinci_cpufreq {
+	struct device *dev;
+	struct clk *armclk;
+	struct clk *asyncclk;
+	unsigned long asyncrate;
+};
+static struct davinci_cpufreq cpufreq;
+
+static int davinci_verify_speed(struct cpufreq_policy *policy)
+{
+	struct davinci_cpufreq_config *pdata = cpufreq.dev->platform_data;
+	struct cpufreq_frequency_table *freq_table = pdata->freq_table;
+	struct clk *armclk = cpufreq.armclk;
+
+	if (freq_table)
+		return cpufreq_frequency_table_verify(policy, freq_table);
+
+	if (policy->cpu)
+		return -EINVAL;
+
+	cpufreq_verify_within_cpu_limits(policy);
+	policy->min = clk_round_rate(armclk, policy->min * 1000) / 1000;
+	policy->max = clk_round_rate(armclk, policy->max * 1000) / 1000;
+	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
+						policy->cpuinfo.max_freq);
+	return 0;
+}
+
+static int davinci_target(struct cpufreq_policy *policy, unsigned int idx)
+{
+	struct davinci_cpufreq_config *pdata = cpufreq.dev->platform_data;
+	struct clk *armclk = cpufreq.armclk;
+	unsigned int old_freq, new_freq;
+	int ret = 0;
+
+	old_freq = policy->cur;
+	new_freq = pdata->freq_table[idx].frequency;
+
+	/* if moving to higher frequency, up the voltage beforehand */
+	if (pdata->set_voltage && new_freq > old_freq) {
+		ret = pdata->set_voltage(idx);
+		if (ret)
+			return ret;
+	}
+
+	ret = clk_set_rate(armclk, idx);
+	if (ret)
+		return ret;
+
+	if (cpufreq.asyncclk) {
+		ret = clk_set_rate(cpufreq.asyncclk, cpufreq.asyncrate);
+		if (ret)
+			return ret;
+	}
+
+	/* if moving to lower freq, lower the voltage after lowering freq */
+	if (pdata->set_voltage && new_freq < old_freq)
+		pdata->set_voltage(idx);
+
+	return 0;
+}
+
+static int davinci_cpu_init(struct cpufreq_policy *policy)
+{
+	int result = 0;
+	struct davinci_cpufreq_config *pdata = cpufreq.dev->platform_data;
+	struct cpufreq_frequency_table *freq_table = pdata->freq_table;
+
+	if (policy->cpu != 0)
+		return -EINVAL;
+
+	/* Finish platform specific initialization */
+	if (pdata->init) {
+		result = pdata->init();
+		if (result)
+			return result;
+	}
+
+	policy->clk = cpufreq.armclk;
+
+	/*
+	 * Time measurement across the target() function yields ~1500-1800us
+	 * time taken with no drivers on notification list.
+	 * Setting the latency to 2000 us to accommodate addition of drivers
+	 * to pre/post change notification list.
+	 */
+	return cpufreq_generic_init(policy, freq_table, 2000 * 1000);
+}
+
+static struct cpufreq_driver davinci_driver = {
+	.flags		= CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
+	.verify		= davinci_verify_speed,
+	.target_index	= davinci_target,
+	.get		= cpufreq_generic_get,
+	.init		= davinci_cpu_init,
+	.name		= "davinci",
+	.attr		= cpufreq_generic_attr,
+};
+
+static int __init davinci_cpufreq_probe(struct platform_device *pdev)
+{
+	struct davinci_cpufreq_config *pdata = pdev->dev.platform_data;
+	struct clk *asyncclk;
+
+	if (!pdata)
+		return -EINVAL;
+	if (!pdata->freq_table)
+		return -EINVAL;
+
+	cpufreq.dev = &pdev->dev;
+
+	cpufreq.armclk = clk_get(NULL, "arm");
+	if (IS_ERR(cpufreq.armclk)) {
+		dev_err(cpufreq.dev, "Unable to get ARM clock\n");
+		return PTR_ERR(cpufreq.armclk);
+	}
+
+	asyncclk = clk_get(cpufreq.dev, "async");
+	if (!IS_ERR(asyncclk)) {
+		cpufreq.asyncclk = asyncclk;
+		cpufreq.asyncrate = clk_get_rate(asyncclk);
+	}
+
+	return cpufreq_register_driver(&davinci_driver);
+}
+
+static int __exit davinci_cpufreq_remove(struct platform_device *pdev)
+{
+	clk_put(cpufreq.armclk);
+
+	if (cpufreq.asyncclk)
+		clk_put(cpufreq.asyncclk);
+
+	return cpufreq_unregister_driver(&davinci_driver);
+}
+
+static struct platform_driver davinci_cpufreq_driver = {
+	.driver = {
+		.name	 = "cpufreq-davinci",
+	},
+	.remove = __exit_p(davinci_cpufreq_remove),
+};
+
+int __init davinci_cpufreq_init(void)
+{
+	return platform_driver_probe(&davinci_cpufreq_driver,
+							davinci_cpufreq_probe);
+}
+