firmware: xilinx: Add system shutdown API interface

Add system shutdown API interface which asks firmware to
perform system shutdown/restart.
Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lore.kernel.org/r/1587761887-4279-24-git-send-email-jolly.shah@xilinx.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/firmware/xilinx/zynqmp.c

@@ -875,6 +875,19 @@ int zynqmp_pm_aes_engine(const u64 address, u32 *out)
 }
 EXPORT_SYMBOL_GPL(zynqmp_pm_aes_engine);
 
+/**
+ * zynqmp_pm_system_shutdown - PM call to request a system shutdown or restart
+ * @type:	Shutdown or restart? 0 for shutdown, 1 for restart
+ * @subtype:	Specifies which system should be restarted or shut down
+ *
+ * Return:	Returns status, either success or error+reason
+ */
+int zynqmp_pm_system_shutdown(const u32 type, const u32 subtype)
+{
+	return zynqmp_pm_invoke_fn(PM_SYSTEM_SHUTDOWN, type, subtype,
+				   0, 0, NULL);
+}
+
 static ssize_t ggs_show(struct device *device,
 			struct device_attribute *attr,
 			char *buf,

include/linux/firmware/xlnx-zynqmp.h

@@ -64,6 +64,7 @@
 
 enum pm_api_id {
 	PM_GET_API_VERSION = 1,
+	PM_SYSTEM_SHUTDOWN = 12,
 	PM_REQUEST_NODE = 13,
 	PM_RELEASE_NODE,
 	PM_SET_REQUIREMENT,
@@ -340,6 +341,7 @@ int zynqmp_pm_write_ggs(u32 index, u32 value);
 int zynqmp_pm_read_ggs(u32 index, u32 *value);
 int zynqmp_pm_write_pggs(u32 index, u32 value);
 int zynqmp_pm_read_pggs(u32 index, u32 *value);
+int zynqmp_pm_system_shutdown(const u32 type, const u32 subtype);
 #else
 static inline struct zynqmp_eemi_ops *zynqmp_pm_get_eemi_ops(void)
 {
@@ -482,6 +484,10 @@ static inline int zynqmp_pm_read_pggs(u32 index, u32 *value)
 {
 	return -ENODEV;
 }
+static inline int zynqmp_pm_system_shutdown(const u32 type, const u32 subtype)
+{
+	return -ENODEV;
+}
 #endif
 
 #endif /* __FIRMWARE_ZYNQMP_H__ */