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>

diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
index e480e0af632c1c6a654b41afc3be1408889ee142..eabd01383cd6ef9d74931b8083bef6d14d665d96 100644 (file)
--- 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},
        {},
 };
 

diff --git a/include/uapi/linux/psci.h b/include/uapi/linux/psci.h
index b3bcabe380da8cf1c1e069bc98945bae1505551f..581f72085c334f4ca27cd42bc1bdd5a01f8391fe 100644 (file)
--- a/include/uapi/linux/psci.h
+++ b/include/uapi/linux/psci.h
@@ -49,6 +49,7 @@
 
 #define PSCI_1_0_FN_PSCI_FEATURES              PSCI_0_2_FN(10)
 #define PSCI_1_0_FN_SYSTEM_SUSPEND             PSCI_0_2_FN(14)
+#define PSCI_1_0_FN_SET_SUSPEND_MODE           PSCI_0_2_FN(15)
 
 #define PSCI_1_0_FN64_SYSTEM_SUSPEND           PSCI_0_2_FN64(14)
 
@@ -97,6 +98,10 @@
 #define PSCI_1_0_FEATURES_CPU_SUSPEND_PF_MASK  \
                        (0x1 << PSCI_1_0_FEATURES_CPU_SUSPEND_PF_SHIFT)
 
+#define PSCI_1_0_OS_INITIATED                  BIT(0)
+#define PSCI_1_0_SUSPEND_MODE_PC               0
+#define PSCI_1_0_SUSPEND_MODE_OSI              1
+
 /* PSCI return values (inclusive of all PSCI versions) */
 #define PSCI_RET_SUCCESS                       0
 #define PSCI_RET_NOT_SUPPORTED                 -1