1 files changed, 117 insertions, 0 deletions
diff --git a/drivers/cpufreq/arm_big_little_dt.c b/drivers/cpufreq/arm_big_little_dt.c
new file mode 100644
index 000000000..36d91dba2
--- /dev/null
+++ b/drivers/cpufreq/arm_big_little_dt.c
@@ -0,0 +1,117 @@
+/*
+ * Generic big.LITTLE CPUFreq Interface driver
+ *
+ * It provides necessary ops to arm_big_little cpufreq driver and gets
+ * Frequency information from Device Tree. Freq table in DT must be in KHz.
+ *
+ * Copyright (C) 2013 Linaro.
+ * Viresh Kumar <viresh.kumar@linaro.org>
+ *
+ * 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.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/cpufreq.h>
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/pm_opp.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include "arm_big_little.h"
+
+/* get cpu node with valid operating-points */
+static struct device_node *get_cpu_node_with_valid_op(int cpu)
+{
+	struct device_node *np = of_cpu_device_node_get(cpu);
+
+	if (!of_get_property(np, "operating-points", NULL)) {
+		of_node_put(np);
+		np = NULL;
+	}
+
+	return np;
+}
+
+static int dt_init_opp_table(struct device *cpu_dev)
+{
+	struct device_node *np;
+	int ret;
+
+	np = of_node_get(cpu_dev->of_node);
+	if (!np) {
+		pr_err("failed to find cpu%d node\n", cpu_dev->id);
+		return -ENOENT;
+	}
+
+	ret = of_init_opp_table(cpu_dev);
+	of_node_put(np);
+
+	return ret;
+}
+
+static int dt_get_transition_latency(struct device *cpu_dev)
+{
+	struct device_node *np;
+	u32 transition_latency = CPUFREQ_ETERNAL;
+
+	np = of_node_get(cpu_dev->of_node);
+	if (!np) {
+		pr_info("Failed to find cpu node. Use CPUFREQ_ETERNAL transition latency\n");
+		return CPUFREQ_ETERNAL;
+	}
+
+	of_property_read_u32(np, "clock-latency", &transition_latency);
+	of_node_put(np);
+
+	pr_debug("%s: clock-latency: %d\n", __func__, transition_latency);
+	return transition_latency;
+}
+
+static struct cpufreq_arm_bL_ops dt_bL_ops = {
+	.name	= "dt-bl",
+	.get_transition_latency = dt_get_transition_latency,
+	.init_opp_table = dt_init_opp_table,
+	.free_opp_table = of_free_opp_table,
+};
+
+static int generic_bL_probe(struct platform_device *pdev)
+{
+	struct device_node *np;
+
+	np = get_cpu_node_with_valid_op(0);
+	if (!np)
+		return -ENODEV;
+
+	of_node_put(np);
+	return bL_cpufreq_register(&dt_bL_ops);
+}
+
+static int generic_bL_remove(struct platform_device *pdev)
+{
+	bL_cpufreq_unregister(&dt_bL_ops);
+	return 0;
+}
+
+static struct platform_driver generic_bL_platdrv = {
+	.driver = {
+		.name	= "arm-bL-cpufreq-dt",
+	},
+	.probe		= generic_bL_probe,
+	.remove		= generic_bL_remove,
+};
+module_platform_driver(generic_bL_platdrv);
+
+MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
+MODULE_DESCRIPTION("Generic ARM big LITTLE cpufreq driver via DT");
+MODULE_LICENSE("GPL v2");