[Intel-gfx] [PATCH i-g-t 6/7] lib/igt_aux: Add helper to query suspend-to-mem modes

[Mika Kuoppala]

From: Imre Deak <imre.deak at intel.com>

Add a helper to query the supported and currently selected
suspend-to-mem modes.

v2:
- Fix for old kernels where the mem_sleep sysfs file didn't yet exist.

Signed-off-by: Imre Deak <imre.deak at intel.com>
---
 lib/igt_aux.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++++++
 lib/igt_aux.h | 24 +++++++++++++++
 2 files changed, 105 insertions(+)

diff --git a/lib/igt_aux.c b/lib/igt_aux.c
index 578f8579..f2cb3247 100644
--- a/lib/igt_aux.c
+++ b/lib/igt_aux.c
@@ -827,6 +827,87 @@ static uint32_t get_supported_suspend_states(int power_dir)
 	return state_mask;
 }
 
+static const char *suspend_to_mem_mode_name[] = {
+	[SUSPEND_TO_MEM_S2IDLE] = "s2idle",
+	[SUSPEND_TO_MEM_SHALLOW] = "shallow",
+	[SUSPEND_TO_MEM_DEEP] = "deep",
+};
+
+static uint32_t
+get_supported_suspend_to_mem_modes(int power_dir,
+				   enum igt_suspend_to_mem_mode *selected_mode)
+{
+	char *modes;
+	char *mode_name;
+	uint32_t mode_mask;
+	bool selected_found = false;
+
+	/*
+	 * Other modes than deep sleep were only introduced with the mem_sleep
+	 * sysfs file.
+	 */
+	modes = igt_sysfs_get(power_dir, "mem_sleep");
+	if (!modes) {
+		*selected_mode = SUSPEND_TO_MEM_DEEP;
+		return 1 << SUSPEND_TO_MEM_DEEP;
+	}
+
+	mode_mask = 0;
+	for (mode_name = strtok(modes, " "); mode_name;
+	     mode_name = strtok(NULL, " ")) {
+		enum igt_suspend_to_mem_mode mode;
+		bool selected = false;
+
+		if (mode_name[0] == '[') {
+			char *e = &mode_name[strlen(mode_name) - 1];
+
+			igt_assert(!selected_found);
+			igt_assert(*e == ']');
+			mode_name++;
+			*e = '\0';
+
+			selected = true;
+		}
+
+		for (mode = SUSPEND_TO_MEM_S2IDLE;
+		     mode < SUSPEND_TO_MEM_NUM;
+		     mode++)
+			if (strcmp(mode_name,
+				   suspend_to_mem_mode_name[mode]) == 0)
+				break;
+		igt_assert(mode < SUSPEND_TO_MEM_NUM);
+		mode_mask |= 1 << mode;
+		if (selected) {
+			selected_found = true;
+			if (selected_mode)
+				*selected_mode = mode;
+		}
+	}
+
+	igt_assert(selected_found);
+
+	free(modes);
+
+	return mode_mask;
+}
+
+/**
+ * igt_get_suspend_to_mem_mode:
+ *
+ * Returns the currently selected @igt_suspend_to_mem_mode.
+ */
+enum igt_suspend_to_mem_mode igt_get_suspend_to_mem_mode(void)
+{
+	int power_dir;
+	enum igt_suspend_to_mem_mode mode;
+
+	igt_require((power_dir = open("/sys/power", O_RDONLY)) >= 0);
+	(void)get_supported_suspend_to_mem_modes(power_dir, &mode);
+	close(power_dir);
+
+	return mode;
+}
+
 /**
  * igt_system_suspend_autoresume:
  * @state: an #igt_suspend_state, the target suspend state
diff --git a/lib/igt_aux.h b/lib/igt_aux.h
index 04d22904..7ccaa8c4 100644
--- a/lib/igt_aux.h
+++ b/lib/igt_aux.h
@@ -184,10 +184,34 @@ enum igt_suspend_test {
 	SUSPEND_TEST_NUM,
 };
 
+/**
+ * igt_suspend_to_mem_mode:
+ * @SUSPEND_TO_MEM_S2IDLE: suspend to mem maps to @SUSPEND_STATE_FREEZE
+ * @SUSPEND_TO_MEM_SHALLOW: suspend to mem maps to @SUSPEND_STATE_STANDBY
+ * @SUSPEND_TO_MEM_DEEP: suspend to mem will target the ACPI S3 state
+ *
+ * The target system state when suspending to mem:
+ * - Suspending with @SUSPEND_STATE_MEM/@SUSPEND_TO_MEM_S2IDLE is equivalent to
+ *   suspending with @SUSPEND_STATE_FREEZE.
+ * - Suspending with @SUSPEND_STATE_MEM/@SUSPEND_TO_MEM_SHALLOW is equivalent to
+ *   suspending with @SUSPEND_STATE_STANDBY.
+ * - Suspending with @SUSPEND_STATE_MEM/@SUSPEND_TO_MEM_DEEP will target the
+ *   ACPI S3 state.
+ */
+enum igt_suspend_to_mem_mode {
+	SUSPEND_TO_MEM_S2IDLE,
+	SUSPEND_TO_MEM_SHALLOW,
+	SUSPEND_TO_MEM_DEEP,
+
+	/*< private >*/
+	SUSPEND_TO_MEM_NUM,
+};
+
 void igt_system_suspend_autoresume(enum igt_suspend_state state,
 				   enum igt_suspend_test test);
 void igt_set_autoresume_delay(int delay_secs);
 int igt_get_autoresume_delay(enum igt_suspend_state state);
+enum igt_suspend_to_mem_mode igt_get_suspend_to_mem_mode(void);
 
 /* dropping priviledges */
 void igt_drop_root(void);
-- 
2.17.1