drivers: firmware: psci: Announce support for OS initiated suspend mode

PSCI firmware v1.0+, supports two different modes for CPU_SUSPEND.
The Platform Coordinated mode, which is the default and mandatory
mode, while support for the OS initiated (OSI) mode is optional.

In some cases it's interesting for the user/developer to know if
the OSI mode is supported by the PSCI FW, so print a message to
the log if that is the case.

Co-developed-by: Lina Iyer <lina.iyer@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 20 insertions, 1 deletions

diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
index e480e0af632c..eabd01383cd6 100644
--- a/drivers/firmware/psci/psci.c
+++ b/drivers/firmware/psci/psci.c
@@ -95,6 +95,11 @@ static inline bool psci_has_ext_power_state(void)
 				PSCI_1_0_FEATURES_CPU_SUSPEND_PF_MASK;
 }
 
+static inline bool psci_has_osi_support(void)
+{
+	return psci_cpu_suspend_feature & PSCI_1_0_OS_INITIATED;
+}
+
 static inline bool psci_power_state_loses_context(u32 state)
 {
 	const u32 mask = psci_has_ext_power_state() ?
@@ -659,10 +664,24 @@ static int __init psci_0_1_init(struct device_node *np)
 	return 0;
 }
 
+static int __init psci_1_0_init(struct device_node *np)
+{
+	int err;
+
+	err = psci_0_2_init(np);
+	if (err)
+		return err;
+
+	if (psci_has_osi_support())
+		pr_info("OSI mode supported.\n");
+
+	return 0;
+}
+
 static const struct of_device_id psci_of_match[] __initconst = {
 	{ .compatible = "arm,psci",	.data = psci_0_1_init},
 	{ .compatible = "arm,psci-0.2",	.data = psci_0_2_init},
-	{ .compatible = "arm,psci-1.0",	.data = psci_0_2_init},
+	{ .compatible = "arm,psci-1.0",	.data = psci_1_0_init},
 	{},
 };