712eddf702
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 <ccross@google.com> Cc: Kukjin Kim <kgene.kim@samsung.com> Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com> Cc: Tomasz Figa <tomasz.figa@gmail.com> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Kukjin Kim <kgene@kernel.org>
146 lines
3.4 KiB
C
146 lines
3.4 KiB
C
/*
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* Copyright (c) 2011-2014 Samsung Electronics Co., Ltd.
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* http://www.samsung.com
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*
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* Coupled cpuidle support based on the work of:
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* Colin Cross <ccross@android.com>
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* Daniel Lezcano <daniel.lezcano@linaro.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/cpuidle.h>
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#include <linux/cpu_pm.h>
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#include <linux/export.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/of.h>
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#include <linux/platform_data/cpuidle-exynos.h>
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#include <asm/proc-fns.h>
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#include <asm/suspend.h>
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#include <asm/cpuidle.h>
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static atomic_t exynos_idle_barrier;
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static struct cpuidle_exynos_data *exynos_cpuidle_pdata;
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static void (*exynos_enter_aftr)(void);
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static int exynos_enter_coupled_lowpower(struct cpuidle_device *dev,
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struct cpuidle_driver *drv,
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int index)
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{
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int ret;
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exynos_cpuidle_pdata->pre_enter_aftr();
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/*
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* Waiting all cpus to reach this point at the same moment
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*/
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cpuidle_coupled_parallel_barrier(dev, &exynos_idle_barrier);
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/*
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* Both cpus will reach this point at the same time
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*/
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ret = dev->cpu ? exynos_cpuidle_pdata->cpu1_powerdown()
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: exynos_cpuidle_pdata->cpu0_enter_aftr();
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if (ret)
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index = ret;
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/*
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* Waiting all cpus to finish the power sequence before going further
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*/
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cpuidle_coupled_parallel_barrier(dev, &exynos_idle_barrier);
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exynos_cpuidle_pdata->post_enter_aftr();
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return index;
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}
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static int exynos_enter_lowpower(struct cpuidle_device *dev,
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struct cpuidle_driver *drv,
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int index)
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{
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int new_index = index;
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/* AFTR can only be entered when cores other than CPU0 are offline */
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if (num_online_cpus() > 1 || dev->cpu != 0)
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new_index = drv->safe_state_index;
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if (new_index == 0)
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return arm_cpuidle_simple_enter(dev, drv, new_index);
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exynos_enter_aftr();
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return new_index;
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}
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static struct cpuidle_driver exynos_idle_driver = {
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.name = "exynos_idle",
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.owner = THIS_MODULE,
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.states = {
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[0] = ARM_CPUIDLE_WFI_STATE,
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[1] = {
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.enter = exynos_enter_lowpower,
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.exit_latency = 300,
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.target_residency = 100000,
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.name = "C1",
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.desc = "ARM power down",
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},
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},
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.state_count = 2,
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.safe_state_index = 0,
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};
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static struct cpuidle_driver exynos_coupled_idle_driver = {
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.name = "exynos_coupled_idle",
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.owner = THIS_MODULE,
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.states = {
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[0] = ARM_CPUIDLE_WFI_STATE,
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[1] = {
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.enter = exynos_enter_coupled_lowpower,
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.exit_latency = 5000,
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.target_residency = 10000,
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.flags = CPUIDLE_FLAG_COUPLED |
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CPUIDLE_FLAG_TIMER_STOP,
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.name = "C1",
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.desc = "ARM power down",
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},
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},
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.state_count = 2,
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.safe_state_index = 0,
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};
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static int exynos_cpuidle_probe(struct platform_device *pdev)
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{
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int ret;
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if (of_machine_is_compatible("samsung,exynos4210")) {
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exynos_cpuidle_pdata = pdev->dev.platform_data;
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ret = cpuidle_register(&exynos_coupled_idle_driver,
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cpu_possible_mask);
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} else {
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exynos_enter_aftr = (void *)(pdev->dev.platform_data);
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ret = cpuidle_register(&exynos_idle_driver, NULL);
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}
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if (ret) {
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dev_err(&pdev->dev, "failed to register cpuidle driver\n");
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return ret;
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}
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return 0;
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}
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static struct platform_driver exynos_cpuidle_driver = {
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.probe = exynos_cpuidle_probe,
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.driver = {
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.name = "exynos_cpuidle",
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},
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};
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module_platform_driver(exynos_cpuidle_driver);
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