The current documented description of the GENPD_FLAG_* flags, are too
simplified, so let's extend them.
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
---
include/linux/pm_domain.h | 35 ++++++++++++++++++++++++++++++-----
1 file changed, 30 insertions(+), 5 deletions(-)
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 776c546d581a..3b5d7280e52e 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -17,11 +17,36 @@
#include <linux/notifier.h>
#include <linux/spinlock.h>
-/* Defines used for the flags field in the struct generic_pm_domain */
-#define GENPD_FLAG_PM_CLK (1U << 0) /* PM domain uses PM clk */
-#define GENPD_FLAG_IRQ_SAFE (1U << 1) /* PM domain operates in atomic */
-#define GENPD_FLAG_ALWAYS_ON (1U << 2) /* PM domain is always powered on */
-#define GENPD_FLAG_ACTIVE_WAKEUP (1U << 3) /* Keep devices active if wakeup */
+/*
+ * Flags to control the behaviour of a genpd.
+ *
+ * These flags may be set in the struct generic_pm_domain's flags field by a
+ * genpd backend driver. The flags must be set before it calls pm_genpd_init(),
+ * which initializes a genpd.
+ *
+ * GENPD_FLAG_PM_CLK: Instructs genpd to use the PM clk framework,
+ * while powering on/off attached devices.
+ *
+ * GENPD_FLAG_IRQ_SAFE: This informs genpd that its backend callbacks,
+ * ->power_on|off(), doesn't sleep. Hence, these
+ * can be invoked from within atomic context, which
+ * enables genpd to power on/off the PM domain,
+ * even when pm_runtime_is_irq_safe() returns true,
+ * for any of its attached devices. Note that, a
+ * genpd having this flag set, requires its
+ * masterdomains to also have it set.
+ *
+ * GENPD_FLAG_ALWAYS_ON: Instructs genpd to always keep the PM domain
+ * powered on.
+ *
+ * GENPD_FLAG_ACTIVE_WAKEUP: Instructs genpd to keep the PM domain powered
+ * on, in case any of its attached devices is used
+ * in the wakeup path to serve system wakeups.
+ */
+#define GENPD_FLAG_PM_CLK (1U << 0)
+#define GENPD_FLAG_IRQ_SAFE (1U << 1)
+#define GENPD_FLAG_ALWAYS_ON (1U << 2)
+#define GENPD_FLAG_ACTIVE_WAKEUP (1U << 3)
enum gpd_status {
GPD_STATE_ACTIVE = 0, /* PM domain is active */
--
2.17.1
