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Diffstat (limited to 'arch/arm/mach-kirkwood/cpuidle.c')
-rw-r--r--arch/arm/mach-kirkwood/cpuidle.c73
1 files changed, 73 insertions, 0 deletions
diff --git a/arch/arm/mach-kirkwood/cpuidle.c b/arch/arm/mach-kirkwood/cpuidle.c
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+/*
+ * arch/arm/mach-kirkwood/cpuidle.c
+ *
+ * CPU idle Marvell Kirkwood SoCs
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ *
+ * The cpu idle uses wait-for-interrupt and DDR self refresh in order
+ * to implement two idle states -
+ * #1 wait-for-interrupt
+ * #2 wait-for-interrupt and DDR self refresh
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/cpuidle.h>
+#include <linux/io.h>
+#include <linux/export.h>
+#include <asm/proc-fns.h>
+#include <asm/cpuidle.h>
+#include <mach/kirkwood.h>
+
+#define KIRKWOOD_MAX_STATES 2
+
+/* Actual code that puts the SoC in different idle states */
+static int kirkwood_enter_idle(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv,
+ int index)
+{
+ writel(0x7, DDR_OPERATION_BASE);
+ cpu_do_idle();
+
+ return index;
+}
+
+static struct cpuidle_driver kirkwood_idle_driver = {
+ .name = "kirkwood_idle",
+ .owner = THIS_MODULE,
+ .en_core_tk_irqen = 1,
+ .states[0] = ARM_CPUIDLE_WFI_STATE,
+ .states[1] = {
+ .enter = kirkwood_enter_idle,
+ .exit_latency = 10,
+ .target_residency = 100000,
+ .flags = CPUIDLE_FLAG_TIME_VALID,
+ .name = "DDR SR",
+ .desc = "WFI and DDR Self Refresh",
+ },
+ .state_count = KIRKWOOD_MAX_STATES,
+};
+
+static DEFINE_PER_CPU(struct cpuidle_device, kirkwood_cpuidle_device);
+
+/* Initialize CPU idle by registering the idle states */
+static int kirkwood_init_cpuidle(void)
+{
+ struct cpuidle_device *device;
+
+ device = &per_cpu(kirkwood_cpuidle_device, smp_processor_id());
+ device->state_count = KIRKWOOD_MAX_STATES;
+
+ cpuidle_register_driver(&kirkwood_idle_driver);
+ if (cpuidle_register_device(device)) {
+ printk(KERN_ERR "kirkwood_init_cpuidle: Failed registering\n");
+ return -EIO;
+ }
+ return 0;
+}
+
+device_initcall(kirkwood_init_cpuidle);