diff options
Diffstat (limited to 'drivers/cpuidle/cpuidle-exynos.c')
-rw-r--r-- | drivers/cpuidle/cpuidle-exynos.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/drivers/cpuidle/cpuidle-exynos.c b/drivers/cpuidle/cpuidle-exynos.c new file mode 100644 index 000000000..0171a6e19 --- /dev/null +++ b/drivers/cpuidle/cpuidle-exynos.c @@ -0,0 +1,146 @@ +/* + * Copyright (c) 2011-2014 Samsung Electronics Co., Ltd. + * http://www.samsung.com + * + * Coupled cpuidle support based on the work of: + * Colin Cross <ccross@android.com> + * Daniel Lezcano <daniel.lezcano@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. +*/ + +#include <linux/cpuidle.h> +#include <linux/cpu_pm.h> +#include <linux/export.h> +#include <linux/init.h> +#include <linux/platform_device.h> +#include <linux/of.h> +#include <linux/platform_data/cpuidle-exynos.h> + +#include <asm/suspend.h> +#include <asm/cpuidle.h> + +static atomic_t exynos_idle_barrier; + +static struct cpuidle_exynos_data *exynos_cpuidle_pdata; +static void (*exynos_enter_aftr)(void); + +static int exynos_enter_coupled_lowpower(struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index) +{ + int ret; + + exynos_cpuidle_pdata->pre_enter_aftr(); + + /* + * Waiting all cpus to reach this point at the same moment + */ + cpuidle_coupled_parallel_barrier(dev, &exynos_idle_barrier); + + /* + * Both cpus will reach this point at the same time + */ + ret = dev->cpu ? exynos_cpuidle_pdata->cpu1_powerdown() + : exynos_cpuidle_pdata->cpu0_enter_aftr(); + if (ret) + index = ret; + + /* + * Waiting all cpus to finish the power sequence before going further + */ + cpuidle_coupled_parallel_barrier(dev, &exynos_idle_barrier); + + exynos_cpuidle_pdata->post_enter_aftr(); + + return index; +} + +static int exynos_enter_lowpower(struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index) +{ + int new_index = index; + + /* AFTR can only be entered when cores other than CPU0 are offline */ + if (num_online_cpus() > 1 || dev->cpu != 0) + new_index = drv->safe_state_index; + + if (new_index == 0) + return arm_cpuidle_simple_enter(dev, drv, new_index); + + exynos_enter_aftr(); + + return new_index; +} + +static struct cpuidle_driver exynos_idle_driver = { + .name = "exynos_idle", + .owner = THIS_MODULE, + .states = { + [0] = ARM_CPUIDLE_WFI_STATE, + [1] = { + .enter = exynos_enter_lowpower, + .exit_latency = 300, + .target_residency = 100000, + .name = "C1", + .desc = "ARM power down", + }, + }, + .state_count = 2, + .safe_state_index = 0, +}; + +static struct cpuidle_driver exynos_coupled_idle_driver = { + .name = "exynos_coupled_idle", + .owner = THIS_MODULE, + .states = { + [0] = ARM_CPUIDLE_WFI_STATE, + [1] = { + .enter = exynos_enter_coupled_lowpower, + .exit_latency = 5000, + .target_residency = 10000, + .flags = CPUIDLE_FLAG_COUPLED | + CPUIDLE_FLAG_TIMER_STOP, + .name = "C1", + .desc = "ARM power down", + }, + }, + .state_count = 2, + .safe_state_index = 0, +}; + +static int exynos_cpuidle_probe(struct platform_device *pdev) +{ + int ret; + + if (IS_ENABLED(CONFIG_SMP) && + (of_machine_is_compatible("samsung,exynos4210") || + of_machine_is_compatible("samsung,exynos3250"))) { + exynos_cpuidle_pdata = pdev->dev.platform_data; + + ret = cpuidle_register(&exynos_coupled_idle_driver, + cpu_possible_mask); + } else { + exynos_enter_aftr = (void *)(pdev->dev.platform_data); + + ret = cpuidle_register(&exynos_idle_driver, NULL); + } + + if (ret) { + dev_err(&pdev->dev, "failed to register cpuidle driver\n"); + return ret; + } + + return 0; +} + +static struct platform_driver exynos_cpuidle_driver = { + .probe = exynos_cpuidle_probe, + .driver = { + .name = "exynos_cpuidle", + }, +}; +builtin_platform_driver(exynos_cpuidle_driver); |