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authorBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>2015-01-24 08:05:50 +0300
committerKukjin Kim <kgene@kernel.org>2015-01-30 02:39:15 +0300
commit712eddf70225ab5ae65e946e22d2dfe6b93e8dd1 (patch)
tree62477a0a4b364cd2e87786481ee6dfe03e3fd569 /drivers/cpuidle/cpuidle-exynos.c
parent865e8b76a04d018f23d809ebf735c52105e3adb2 (diff)
downloadlinux-712eddf70225ab5ae65e946e22d2dfe6b93e8dd1.tar.xz
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 <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>
Diffstat (limited to 'drivers/cpuidle/cpuidle-exynos.c')
-rw-r--r--drivers/cpuidle/cpuidle-exynos.c76
1 files changed, 71 insertions, 5 deletions
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 <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.
@@ -13,13 +16,49 @@
#include <linux/export.h>
#include <linux/module.h>
#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/platform_data/cpuidle-exynos.h>
#include <asm/proc-fns.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)
@@ -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;