rk30: add cpuidle support

diff --git a/arch/arm/mach-rk30/Makefile b/arch/arm/mach-rk30/Makefile
index 7d2f9d805f2d98af30a20fa740fe2bed1942135f..c29cf061c864a2fdfa57ce515b42c12a1e7cc279 100644 (file)
--- a/arch/arm/mach-rk30/Makefile
+++ b/arch/arm/mach-rk30/Makefile
@@ -11,5 +11,6 @@ obj-$(CONFIG_SMP) += platsmp.o headsmp.o
 obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
 obj-$(CONFIG_LOCAL_TIMERS) += localtimer.o
 obj-$(CONFIG_PM) += pm.o
+obj-$(CONFIG_CPU_IDLE) += cpuidle.o
 
 obj-$(CONFIG_MACH_RK30_SDK) += board-rk30-sdk.o board-rk30-sdk-key.o

diff --git a/arch/arm/mach-rk30/cpuidle.c b/arch/arm/mach-rk30/cpuidle.c
new file mode 100644 (file)
index 0000000..11f8b3e
--- /dev/null
+++ b/arch/arm/mach-rk30/cpuidle.c
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2012 ROCKCHIP, Inc.
+ *
+ * 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.
+ */
+
+#define pr_fmt(fmt) "cpuidle: %s: " fmt, __func__
+
+#include <linux/pm.h>
+#include <linux/cpuidle.h>
+#include <linux/suspend.h>
+#include <linux/err.h>
+
+#include <asm/hardware/gic.h>
+#include <asm/io.h>
+
+static bool rk30_gic_interrupt_pending(void)
+{
+       return (readl_relaxed(RK30_GICC_BASE + GIC_CPU_HIGHPRI) != 0x3FF);
+}
+
+static void rk30_wfi_until_interrupt(void)
+{
+retry:
+       cpu_do_idle();
+
+       if (!rk30_gic_interrupt_pending())
+               goto retry;
+}
+
+static int rk30_idle(struct cpuidle_device *dev, struct cpuidle_state *state)
+{
+       ktime_t preidle, postidle;
+
+       local_fiq_disable();
+
+       preidle = ktime_get();
+
+       rk30_wfi_until_interrupt();
+
+       postidle = ktime_get();
+
+       local_fiq_enable();
+       local_irq_enable();
+
+       return ktime_to_us(ktime_sub(postidle, preidle));
+}
+
+static DEFINE_PER_CPU(struct cpuidle_device, rk30_cpuidle_device);
+
+static __initdata struct cpuidle_state rk30_cpuidle_states[] = {
+       {
+               .name = "C1",
+               .desc = "idle",
+               .flags = CPUIDLE_FLAG_TIME_VALID,
+               .exit_latency = 0,
+               .target_residency = 0,
+               .enter = rk30_idle,
+       },
+};
+
+static struct cpuidle_driver rk30_cpuidle_driver = {
+       .name = "rk30_cpuidle",
+       .owner = THIS_MODULE,
+};
+
+static int __init rk30_cpuidle_init(void)
+{
+       struct cpuidle_device *dev;
+       unsigned int cpu;
+       int ret;
+
+       ret = cpuidle_register_driver(&rk30_cpuidle_driver);
+       if (ret) {
+               pr_err("failed to register cpuidle driver: %d\n", ret);
+               return ret;
+       }
+
+       for_each_possible_cpu(cpu) {
+               dev = &per_cpu(rk30_cpuidle_device, cpu);
+               dev->cpu = cpu;
+               dev->state_count = ARRAY_SIZE(rk30_cpuidle_states);
+               memcpy(dev->states, rk30_cpuidle_states, sizeof(rk30_cpuidle_states));
+               dev->safe_state = &dev->states[0];
+
+               ret = cpuidle_register_device(dev);
+               if (ret) {
+                       pr_err("failed to register cpuidle device for cpu %u: %d\n", cpu, ret);
+                       return ret;
+               }
+       }
+
+       return 0;
+}
+late_initcall(rk30_cpuidle_init);