From 22b8b85d902b0ff4dffb281303ea5bb0369c17aa Mon Sep 17 00:00:00 2001 From: Peter De Schrijver Date: Thu, 26 Jan 2012 18:22:03 +0200 Subject: ARM: tegra: cpuidle driver for tegra CPUidle driver for tegra. In this version only LP3 (clockgating) is supported. Based on work by: Colin Cross Gary King Signed-off-by: Peter De Schrijver Acked-by: Stephen Warren Tested-by: Stephen Warren Acked-by: Colin Cross Signed-off-by: Olof Johansson --- arch/arm/mach-tegra/cpuidle.c | 107 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 107 insertions(+) create mode 100644 arch/arm/mach-tegra/cpuidle.c (limited to 'arch/arm/mach-tegra/cpuidle.c') diff --git a/arch/arm/mach-tegra/cpuidle.c b/arch/arm/mach-tegra/cpuidle.c new file mode 100644 index 000000000000..d83a8c0296f5 --- /dev/null +++ b/arch/arm/mach-tegra/cpuidle.c @@ -0,0 +1,107 @@ +/* + * arch/arm/mach-tegra/cpuidle.c + * + * CPU idle driver for Tegra CPUs + * + * Copyright (c) 2010-2012, NVIDIA Corporation. + * Copyright (c) 2011 Google, Inc. + * Author: Colin Cross + * Gary King + * + * Rework for 3.3 by Peter De Schrijver + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + */ + +#include +#include +#include +#include +#include + +#include + +extern void tegra_cpu_wfi(void); + +static int tegra_idle_enter_lp3(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index); + +struct cpuidle_driver tegra_idle_driver = { + .name = "tegra_idle", + .owner = THIS_MODULE, + .state_count = 1, + .states = { + [0] = { + .enter = tegra_idle_enter_lp3, + .exit_latency = 10, + .target_residency = 10, + .power_usage = 600, + .flags = CPUIDLE_FLAG_TIME_VALID, + .name = "LP3", + .desc = "CPU flow-controlled", + }, + }, +}; + +static DEFINE_PER_CPU(struct cpuidle_device, tegra_idle_device); + +static int tegra_idle_enter_lp3(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) +{ + ktime_t enter, exit; + s64 us; + + local_irq_disable(); + local_fiq_disable(); + + enter = ktime_get(); + + tegra_cpu_wfi(); + + exit = ktime_sub(ktime_get(), enter); + us = ktime_to_us(exit); + + local_fiq_enable(); + local_irq_enable(); + + dev->last_residency = us; + + return index; +} + +static int __init tegra_cpuidle_init(void) +{ + int ret; + unsigned int cpu; + struct cpuidle_device *dev; + struct cpuidle_driver *drv = &tegra_idle_driver; + + ret = cpuidle_register_driver(&tegra_idle_driver); + if (ret) { + pr_err("CPUidle driver registration failed\n"); + return ret; + } + + for_each_possible_cpu(cpu) { + dev = &per_cpu(tegra_idle_device, cpu); + dev->cpu = cpu; + + dev->state_count = drv->state_count; + ret = cpuidle_register_device(dev); + if (ret) { + pr_err("CPU%u: CPUidle device registration failed\n", + cpu); + return ret; + } + } + return 0; +} +device_initcall(tegra_cpuidle_init); -- cgit v1.2.3