On a numer of Exynos-based boards Linux kernel is running in non-secure
mode under a secure firmware. This means that certain operations need to
be handled in special way, with firmware assistance. System-wide
suspend/resume is an example of such operations.
This patch adds support for firmware-assisted suspend/resume by
leveraging recently introduced suspend and resume firmware operations
and modifying existing suspend/resume paths to account for presence of
secure firmware.
Signed-off-by: Tomasz Figa <t.figa@xxxxxxxxxxx>
---
arch/arm/mach-exynos/firmware.c | 47 +++++++++++++++++++++++++++++++++++++++++
arch/arm/mach-exynos/pm.c | 16 +++++++++-----
2 files changed, 58 insertions(+), 5 deletions(-)
diff --git a/arch/arm/mach-exynos/firmware.c b/arch/arm/mach-exynos/firmware.c
index def7bb4..cd554a1 100644
--- a/arch/arm/mach-exynos/firmware.c
+++ b/arch/arm/mach-exynos/firmware.c
@@ -14,15 +14,21 @@
#include <linux/of.h>
#include <linux/of_address.h>
+#include <asm/cacheflush.h>
#include <asm/cputype.h>
#include <asm/firmware.h>
#include <asm/hardware/cache-l2x0.h>
+#include <asm/suspend.h>
#include <mach/map.h>
#include "common.h"
#include "smc.h"
+#define EXYNOS_SLEEP_MAGIC 0x00000bad
+#define EXYNOS_BOOT_ADDR 0x8
+#define EXYNOS_BOOT_FLAG 0xc
+
static int exynos_do_idle(void)
{
exynos_smc(SMC_CMD_SLEEP, 0, 0, 0);
@@ -66,10 +72,51 @@ static int exynos_set_cpu_boot_addr(int cpu, unsigned long boot_addr)
return 0;
}
+/* For Cortex-A9 Diagnostic and Power control register */
+static unsigned int cp15_power;
+static unsigned int cp15_diag;
+
+static int exynos_cpu_suspend(unsigned long arg)
+{
+ flush_cache_all();
+ outer_flush_all();
+
+ exynos_smc(SMC_CMD_SLEEP, 0, 0, 0);
+
+ pr_info("Failed to suspend the system\n");
+ writel(0, sysram_ns_base_addr + EXYNOS_BOOT_FLAG);
+ return 1;
+}
+
+static int exynos_suspend(void)
+{
+ /* Save Power control and Diagnostic registers */
+ asm ("mrc p15, 0, %0, c15, c0, 0\n"
+ "mrc p15, 0, %1, c15, c0, 1\n"
+ : "=r" (cp15_power), "=r" (cp15_diag) : : "cc");
+
+ writel(EXYNOS_SLEEP_MAGIC, sysram_ns_base_addr + EXYNOS_BOOT_FLAG);
+ writel(virt_to_phys(cpu_resume),
+ sysram_ns_base_addr + EXYNOS_BOOT_ADDR);
+
+ return cpu_suspend(0, exynos_cpu_suspend);
+}
+
+static int exynos_resume(void)
+{
+ exynos_smc(SMC_CMD_C15RESUME, cp15_power, cp15_diag, 0);
+ writel(0, sysram_ns_base_addr + EXYNOS_BOOT_FLAG);
+ outer_resume();
+
+ return 0;
+}
+
static const struct firmware_ops exynos_firmware_ops = {
.do_idle = exynos_do_idle,
.set_cpu_boot_addr = exynos_set_cpu_boot_addr,
.cpu_boot = exynos_cpu_boot,
+ .suspend = exynos_suspend,
+ .resume = exynos_resume,
};
static void exynos_l2_write_sec(unsigned long val, void __iomem *base,
diff --git a/arch/arm/mach-exynos/pm.c b/arch/arm/mach-exynos/pm.c
index f23cc77..ed20318 100644
--- a/arch/arm/mach-exynos/pm.c
+++ b/arch/arm/mach-exynos/pm.c
@@ -23,6 +23,7 @@
#include <linux/clk.h>
#include <asm/cacheflush.h>
+#include <asm/firmware.h>
#include <asm/hardware/cache-l2x0.h>
#include <asm/smp_scu.h>
#include <asm/suspend.h>
@@ -331,12 +332,11 @@ static int exynos_pm_central_resume(void)
static void exynos_pm_resume(void)
{
+ u32 cpuid = read_cpuid_part_number();
+
if (exynos_pm_central_resume())
goto early_wakeup;
- if (read_cpuid_part_number() == ARM_CPU_PART_CORTEX_A9)
- exynos_cpu_restore_register();
-
/* For release retention */
__raw_writel((1 << 28), S5P_PAD_RET_MAUDIO_OPTION);
@@ -353,9 +353,13 @@ static void exynos_pm_resume(void)
s3c_pm_do_restore_core(exynos_core_save, ARRAY_SIZE(exynos_core_save));
- if (read_cpuid_part_number() == ARM_CPU_PART_CORTEX_A9)
+ if (cpuid == ARM_CPU_PART_CORTEX_A9)
scu_enable(S5P_VA_SCU);
+ if (call_firmware_op(resume) == -ENOSYS
+ && cpuid == ARM_CPU_PART_CORTEX_A9)
+ exynos_cpu_restore_register();
+
early_wakeup:
/* Clear SLEEP mode set in INFORM1 */
@@ -391,7 +395,9 @@ static int exynos_suspend_enter(suspend_state_t state)
flush_cache_all();
s3c_pm_check_store();
- ret = cpu_suspend(0, exynos_cpu_suspend);
+ ret = call_firmware_op(suspend);
+ if (ret == -ENOSYS)
+ ret = cpu_suspend(0, exynos_cpu_suspend);
if (ret)
return ret;
--
1.9.3
--
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