From 712eddf70225ab5ae65e946e22d2dfe6b93e8dd1 Mon Sep 17 00:00:00 2001 From: Bartlomiej Zolnierkiewicz Date: Sat, 24 Jan 2015 14:05:50 +0900 Subject: cpuidle: exynos: add coupled cpuidle support for exynos4210 The following patch adds coupled cpuidle support for Exynos4210 to an existing cpuidle-exynos driver. As a result it enables AFTR mode to be used by default on Exynos4210 without the need to hot unplug CPU1 first. The patch is heavily based on earlier cpuidle-exynos4210 driver from Daniel Lezcano: http://www.spinics.net/lists/linux-samsung-soc/msg28134.html Changes from Daniel's code include: - porting code to current kernels - fixing it to work on my setup (by using S5P_INFORM register instead of S5P_VA_SYSRAM one on Revison 1.1 and retrying poking CPU1 out of the BOOT ROM if necessary) - fixing rare lockup caused by waiting for CPU1 to get stuck in the BOOT ROM (CPU hotplug code in arch/arm/mach-exynos/platsmp.c doesn't require this and works fine) - moving Exynos specific code to arch/arm/mach-exynos/pm.c - using cpu_boot_reg_base() helper instead of BOOT_VECTOR macro - using exynos_cpu_*() helpers instead of accessing registers directly - using arch_send_wakeup_ipi_mask() instead of dsb_sev() (this matches CPU hotplug code in arch/arm/mach-exynos/platsmp.c) - integrating separate exynos4210-cpuidle driver into existing exynos-cpuidle one Cc: Colin Cross Cc: Kukjin Kim Cc: Krzysztof Kozlowski Cc: Tomasz Figa Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Daniel Lezcano Acked-by: Kyungmin Park Signed-off-by: Kukjin Kim --- drivers/cpuidle/Kconfig.arm | 1 + drivers/cpuidle/cpuidle-exynos.c | 76 +++++++++++++++++++++++++++++++++++++--- 2 files changed, 72 insertions(+), 5 deletions(-) (limited to 'drivers/cpuidle') diff --git a/drivers/cpuidle/Kconfig.arm b/drivers/cpuidle/Kconfig.arm index 8c16ab20fb15..8e07c9419153 100644 --- a/drivers/cpuidle/Kconfig.arm +++ b/drivers/cpuidle/Kconfig.arm @@ -55,6 +55,7 @@ config ARM_AT91_CPUIDLE config ARM_EXYNOS_CPUIDLE bool "Cpu Idle Driver for the Exynos processors" depends on ARCH_EXYNOS + select ARCH_NEEDS_CPU_IDLE_COUPLED if SMP help Select this to enable cpuidle for Exynos processors diff --git a/drivers/cpuidle/cpuidle-exynos.c b/drivers/cpuidle/cpuidle-exynos.c index 4003a3160865..26f5f29fdb03 100644 --- a/drivers/cpuidle/cpuidle-exynos.c +++ b/drivers/cpuidle/cpuidle-exynos.c @@ -1,8 +1,11 @@ -/* linux/arch/arm/mach-exynos/cpuidle.c - * - * Copyright (c) 2011 Samsung Electronics Co., Ltd. +/* + * Copyright (c) 2011-2014 Samsung Electronics Co., Ltd. * http://www.samsung.com * + * Coupled cpuidle support based on the work of: + * Colin Cross + * Daniel Lezcano + * * 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. @@ -13,13 +16,49 @@ #include #include #include +#include +#include #include #include #include +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) @@ -55,13 +94,40 @@ static struct cpuidle_driver exynos_idle_driver = { .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; - exynos_enter_aftr = (void *)(pdev->dev.platform_data); + if (of_machine_is_compatible("samsung,exynos4210")) { + 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); + } - ret = cpuidle_register(&exynos_idle_driver, NULL); if (ret) { dev_err(&pdev->dev, "failed to register cpuidle driver\n"); return ret; -- cgit v1.2.3