[PATCH v8] ARM: EXYNOS: Use MCPM call-backs to support S2R on Exynos5420
Abhilash Kesavan
a.kesavan at samsung.com
Tue Sep 30 07:59:02 PDT 2014
Use the MCPM layer to handle core suspend/resume on Exynos5420.
Also, restore the entry address setup code post-resume.
Signed-off-by: Abhilash Kesavan <a.kesavan at samsung.com>
Acked-by: Nicolas Pitre <nico at linaro.org>
---
Changes in v2:
- Made use of the MCPM suspend/powered_up call-backs
Changes in v3:
- Used the residency value to indicate the entered state
Changes in v4:
- Checked if MCPM has been enabled to prevent build error
Changes in v5:
- Removed the MCPM flags and just used a local flag to
indicate that we are suspending.
Changes in v6:
- Read the SYS_PWR_REG value to decide if we are suspending
the system.
- Restore the SYS_PWR_REG value post-resume.
- Modified the comments to reflect the first change.
Changes in v7:
- Add the suspend check in exynos_cpu_power_down() rather
than the MCPM back-end.
- Clean-up unnecessary changes related to earlier versions.
Changes in v8:
- Rebased on the latest exynos PMU/PM support patches.
This patch is based on kgene's for-next branch.
http://git.kernel.org/cgit/linux/kernel/git/kgene/linux-samsung.git/log/?h=for-next
Here are the dependencies:
1) Decouple syscon interface from platform devices - v7
http://lkml.org/lkml/2014/9/30/156
2) ARM: Exynos: Convert PMU implementation into a platform driver - v8
http://www.spinics.net/lists/arm-kernel/msg366831.html
3) Exynos5420 PMU/S2R Series - v8
http://www.spinics.net/lists/arm-kernel/msg366846.html
arch/arm/mach-exynos/mcpm-exynos.c | 32 ++++++++++++++++--------
arch/arm/mach-exynos/platsmp.c | 12 +++++++++
arch/arm/mach-exynos/suspend.c | 50 ++++++++++++++++++++++++++++++++++----
3 files changed, 79 insertions(+), 15 deletions(-)
diff --git a/arch/arm/mach-exynos/mcpm-exynos.c b/arch/arm/mach-exynos/mcpm-exynos.c
index dc9a764..b0d3c2e 100644
--- a/arch/arm/mach-exynos/mcpm-exynos.c
+++ b/arch/arm/mach-exynos/mcpm-exynos.c
@@ -15,6 +15,7 @@
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/of_address.h>
+#include <linux/syscore_ops.h>
#include <asm/cputype.h>
#include <asm/cp15.h>
@@ -30,6 +31,8 @@
#define EXYNOS5420_USE_ARM_CORE_DOWN_STATE BIT(29)
#define EXYNOS5420_USE_L2_COMMON_UP_STATE BIT(30)
+static void __iomem *ns_sram_base_addr;
+
/*
* The common v7_exit_coherency_flush API could not be used because of the
* Erratum 799270 workaround. This macro is the same as the common one (in
@@ -318,10 +321,26 @@ static const struct of_device_id exynos_dt_mcpm_match[] = {
{},
};
+static void exynos_mcpm_setup_entry_point(void)
+{
+ /*
+ * U-Boot SPL is hardcoded to jump to the start of ns_sram_base_addr
+ * as part of secondary_cpu_start(). Let's redirect it to the
+ * mcpm_entry_point(). This is done during both secondary boot-up as
+ * well as system resume.
+ */
+ __raw_writel(0xe59f0000, ns_sram_base_addr); /* ldr r0, [pc, #0] */
+ __raw_writel(0xe12fff10, ns_sram_base_addr + 4); /* bx r0 */
+ __raw_writel(virt_to_phys(mcpm_entry_point), ns_sram_base_addr + 8);
+}
+
+static struct syscore_ops exynos_mcpm_syscore_ops = {
+ .resume = exynos_mcpm_setup_entry_point,
+};
+
static int __init exynos_mcpm_init(void)
{
struct device_node *node;
- void __iomem *ns_sram_base_addr;
unsigned int value, i;
int ret;
@@ -387,16 +406,9 @@ static int __init exynos_mcpm_init(void)
pmu_raw_writel(value, EXYNOS_COMMON_OPTION(i));
}
- /*
- * U-Boot SPL is hardcoded to jump to the start of ns_sram_base_addr
- * as part of secondary_cpu_start(). Let's redirect it to the
- * mcpm_entry_point().
- */
- __raw_writel(0xe59f0000, ns_sram_base_addr); /* ldr r0, [pc, #0] */
- __raw_writel(0xe12fff10, ns_sram_base_addr + 4); /* bx r0 */
- __raw_writel(virt_to_phys(mcpm_entry_point), ns_sram_base_addr + 8);
+ exynos_mcpm_setup_entry_point();
- iounmap(ns_sram_base_addr);
+ register_syscore_ops(&exynos_mcpm_syscore_ops);
return ret;
}
diff --git a/arch/arm/mach-exynos/platsmp.c b/arch/arm/mach-exynos/platsmp.c
index adb36a8..222aa3c 100644
--- a/arch/arm/mach-exynos/platsmp.c
+++ b/arch/arm/mach-exynos/platsmp.c
@@ -137,6 +137,18 @@ void exynos_cpu_power_down(int cpu)
*/
void exynos_cpu_power_up(int cpu)
{
+ if (cpu == 0 && (of_machine_is_compatible("samsung,exynos5420") ||
+ of_machine_is_compatible("samsung,exynos5800"))) {
+ /*
+ * Bypass power down for CPU0 during suspend. Check for
+ * the SYS_PWR_REG value to decide if we are suspending
+ * the system.
+ */
+ int val = __raw_readl(pmu_base_addr +
+ EXYNOS5_ARM_CORE0_SYS_PWR_REG);
+ if (!(val & S5P_CORE_LOCAL_PWR_EN))
+ return;
+ }
pmu_raw_writel(S5P_CORE_LOCAL_PWR_EN,
EXYNOS_ARM_CORE_CONFIGURATION(cpu));
}
diff --git a/arch/arm/mach-exynos/suspend.c b/arch/arm/mach-exynos/suspend.c
index 773140c..e32a42c 100644
--- a/arch/arm/mach-exynos/suspend.c
+++ b/arch/arm/mach-exynos/suspend.c
@@ -24,6 +24,7 @@
#include <asm/cacheflush.h>
#include <asm/hardware/cache-l2x0.h>
#include <asm/firmware.h>
+#include <asm/mcpm.h>
#include <asm/smp_scu.h>
#include <asm/suspend.h>
@@ -72,6 +73,7 @@ struct exynos_pm_data {
unsigned int *release_ret_regs;
void (*pm_prepare)(void);
+ void (*pm_resume_prepare)(void);
void (*pm_resume)(void);
int (*pm_suspend)(void);
int (*cpu_suspend)(unsigned long);
@@ -172,9 +174,28 @@ static int exynos_cpu_suspend(unsigned long arg)
static int exynos5420_cpu_suspend(unsigned long arg)
{
- exynos_flush_cache_all();
+ /* MCPM works with HW CPU identifiers */
+ unsigned int mpidr = read_cpuid_mpidr();
+ unsigned int cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+ unsigned int cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+
__raw_writel(0x0, sysram_base_addr + EXYNOS5420_CPU_STATE);
- return exynos_cpu_do_idle();
+
+ if (IS_ENABLED(CONFIG_EXYNOS5420_MCPM)) {
+ mcpm_set_entry_vector(cpu, cluster, exynos_cpu_resume);
+
+ /*
+ * Residency value passed to mcpm_cpu_suspend back-end
+ * has to be given clear semantics. Set to 0 as a
+ * temporary value.
+ */
+ mcpm_cpu_suspend(0);
+ }
+
+ pr_info("Failed to suspend the system\n");
+
+ /* return value != 0 means failure */
+ return 1;
}
static void exynos_pm_set_wakeup_mask(void)
@@ -189,9 +210,6 @@ static void exynos_pm_enter_sleep_mode(void)
/* Set value of power down register for sleep mode */
exynos_sys_powerdown_conf(SYS_SLEEP);
pmu_raw_writel(S5P_CHECK_SLEEP, S5P_INFORM1);
-
- /* ensure at least INFORM0 has the resume address */
- pmu_raw_writel(virt_to_phys(exynos_cpu_resume), S5P_INFORM0);
}
static void exynos_pm_prepare(void)
@@ -206,6 +224,9 @@ static void exynos_pm_prepare(void)
pm_data->num_extra_save);
exynos_pm_enter_sleep_mode();
+
+ /* ensure at least INFORM0 has the resume address */
+ pmu_raw_writel(virt_to_phys(exynos_cpu_resume), S5P_INFORM0);
}
static void exynos5420_pm_prepare(void)
@@ -230,6 +251,10 @@ static void exynos5420_pm_prepare(void)
exynos_pm_enter_sleep_mode();
+ /* ensure at least INFORM0 has the resume address */
+ if (IS_ENABLED(CONFIG_EXYNOS5420_MCPM))
+ pmu_raw_writel(virt_to_phys(mcpm_entry_point), S5P_INFORM0);
+
tmp = pmu_raw_readl(EXYNOS5_ARM_L2_OPTION);
tmp &= ~EXYNOS5_USE_RETENTION;
pmu_raw_writel(tmp, EXYNOS5_ARM_L2_OPTION);
@@ -318,6 +343,12 @@ early_wakeup:
pmu_raw_writel(0x0, S5P_INFORM1);
}
+static void exynos5420_prepare_pm_resume(void)
+{
+ if (IS_ENABLED(CONFIG_EXYNOS5420_MCPM))
+ WARN_ON(mcpm_cpu_powered_up());
+}
+
static void exynos5420_pm_resume(void)
{
unsigned long tmp;
@@ -346,6 +377,12 @@ static void exynos5420_pm_resume(void)
early_wakeup:
+ /* Restore the CPU0 low power state register */
+ tmp = __raw_readl(pmu_base_addr +
+ EXYNOS5_ARM_CORE0_SYS_PWR_REG);
+ pmu_raw_writel(tmp | S5P_CORE_LOCAL_PWR_EN,
+ EXYNOS5_ARM_CORE0_SYS_PWR_REG);
+
tmp = pmu_raw_readl(EXYNOS5420_SFR_AXI_CGDIS1);
tmp &= ~EXYNOS5420_UFS;
pmu_raw_writel(tmp, EXYNOS5420_SFR_AXI_CGDIS1);
@@ -396,6 +433,8 @@ static int exynos_suspend_enter(suspend_state_t state)
if (ret)
return ret;
+ if (pm_data->pm_resume_prepare)
+ pm_data->pm_resume_prepare();
s3c_pm_restore_uarts();
S3C_PMDBG("%s: wakeup stat: %08x\n", __func__,
@@ -453,6 +492,7 @@ static struct exynos_pm_data exynos5420_pm_data = {
.wkup_irq = exynos5250_wkup_irq,
.wake_disable_mask = (0x7F << 7) | (0x1F << 1),
.release_ret_regs = exynos5420_release_ret_regs,
+ .pm_resume_prepare = exynos5420_prepare_pm_resume,
.pm_resume = exynos5420_pm_resume,
.pm_suspend = exynos5420_pm_suspend,
.pm_prepare = exynos5420_pm_prepare,
--
2.1.0
More information about the linux-arm-kernel
mailing list