firmware: arm_sdei: Drop check for /firmware/ node and always register driver

As with most of the drivers, let us register this driver unconditionally
by dropping the checks for presence of firmware nodes(DT) or entries(ACPI).

Further, as mentioned in the commit acafce48 ("firmware: arm_sdei:
Fix DT platform device creation"), the core takes care of creation of
platform device when the appropriate device node is found and probe
is called accordingly.

Let us check only for the presence of ACPI firmware entry before creating
the platform device and flag warning if we fail.
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Cc: James Morse <james.morse@arm.com>
Link: https://lore.kernel.org/r/20200422122823.1390-1-sudeep.holla@arm.comSigned-off-by: Will Deacon <will@kernel.org>

drivers/firmware/arm_sdei.c

@@ -1079,26 +1079,9 @@ static struct platform_driver sdei_driver = {
 	.probe		= sdei_probe,
 };
 
-static bool __init sdei_present_dt(void)
-{
-	struct device_node *np, *fw_np;
-
-	fw_np = of_find_node_by_name(NULL, "firmware");
-	if (!fw_np)
-		return false;
-
-	np = of_find_matching_node(fw_np, sdei_of_match);
-	if (!np)
-		return false;
-	of_node_put(np);
-
-	return true;
-}
-
 static bool __init sdei_present_acpi(void)
 {
 	acpi_status status;
-	struct platform_device *pdev;
 	struct acpi_table_header *sdei_table_header;
 
 	if (acpi_disabled)
@@ -1113,20 +1096,24 @@ static bool __init sdei_present_acpi(void)
 	if (ACPI_FAILURE(status))
 		return false;
 
-	pdev = platform_device_register_simple(sdei_driver.driver.name, 0, NULL,
-					       0);
-	if (IS_ERR(pdev))
-		return false;
-
 	return true;
 }
 
 static int __init sdei_init(void)
 {
-	if (sdei_present_dt() || sdei_present_acpi())
-		platform_driver_register(&sdei_driver);
+	int ret = platform_driver_register(&sdei_driver);
 
-	return 0;
+	if (!ret && sdei_present_acpi()) {
+		struct platform_device *pdev;
+
+		pdev = platform_device_register_simple(sdei_driver.driver.name,
+						       0, NULL, 0);
+		if (IS_ERR(pdev))
+			pr_info("Failed to register ACPI:SDEI platform device %ld\n",
+				PTR_ERR(pdev));
+	}
+
+	return ret;
 }
 
 /*