platform: generic: Add system suspend test

When the system-suspend-test property is present in the domain config
node as shown below, implement system suspend with a simple 5 second
delay followed by a WFI. This allows testing system suspend when the
low-level firmware doesn't support it.

  / {
    chosen {
      opensbi-domains {
          compatible = "opensbi,domain,config";
          system-suspend-test;
      };

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

1 files changed, 31 insertions, 0 deletions

diff --git a/lib/sbi/sbi_system.c b/lib/sbi/sbi_system.c
index 7fa5ea8..6933915 100644
--- a/lib/sbi/sbi_system.c
+++ b/lib/sbi/sbi_system.c
@@ -17,6 +17,7 @@
 #include <sbi/sbi_system.h>
 #include <sbi/sbi_ipi.h>
 #include <sbi/sbi_init.h>
+#include <sbi/sbi_timer.h>
 
 static SBI_LIST_HEAD(reset_devices_list);
 
@@ -108,6 +109,36 @@ void sbi_system_suspend_set_device(struct sbi_system_suspend_device *dev)
 	suspend_dev = dev;
 }
 
+static int sbi_system_suspend_test_check(u32 sleep_type)
+{
+	return sleep_type == SBI_SUSP_SLEEP_TYPE_SUSPEND;
+}
+
+static int sbi_system_suspend_test_suspend(u32 sleep_type,
+					   unsigned long mmode_resume_addr)
+{
+	if (sleep_type != SBI_SUSP_SLEEP_TYPE_SUSPEND)
+		return SBI_EINVAL;
+
+	sbi_timer_mdelay(5000);
+
+	/* Wait for interrupt */
+	wfi();
+
+	return SBI_OK;
+}
+
+static struct sbi_system_suspend_device sbi_system_suspend_test = {
+	.name = "system-suspend-test",
+	.system_suspend_check = sbi_system_suspend_test_check,
+	.system_suspend = sbi_system_suspend_test_suspend,
+};
+
+void sbi_system_suspend_test_enable(void)
+{
+	sbi_system_suspend_set_device(&sbi_system_suspend_test);
+}
+
 bool sbi_system_suspend_supported(u32 sleep_type)
 {
 	return suspend_dev && suspend_dev->system_suspend_check &&