[PATCH v1] soc: fsl: rcpm: Add ACPI support

[kuldip dwivedi]

Add ACPI support in fsl RCPM driver. This is required
to support ACPI S3 state. S3 is the ACPI sleep state
that is known as "sleep" or "suspend to RAM".
It essentially turns off most power of the system but
keeps memory powered.

Signed-off-by: tanveer <tanveer.alam at puresoftware.com>
Signed-off-by: kuldip dwivedi <kuldip.dwivedi at puresoftware.com>
---

Notes:
    1. Add ACPI match table
    2. NXP team members are added for confirming HID changes
    3. There is only one node in ACPI so no need to check for
       current device explicitly
    4. These changes are tested on LX2160A and LS1046A platforms

 drivers/soc/fsl/rcpm.c | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/soc/fsl/rcpm.c b/drivers/soc/fsl/rcpm.c
index a093dbe6d2cb..e75a436fb159 100644
--- a/drivers/soc/fsl/rcpm.c
+++ b/drivers/soc/fsl/rcpm.c
@@ -2,10 +2,12 @@
 //
 // rcpm.c - Freescale QorIQ RCPM driver
 //
-// Copyright 2019 NXP
+// Copyright 2019-2020 NXP
+// Copyright 2020 Puresoftware Ltd.
 //
 // Author: Ran Wang <ran.wang_1 at nxp.com>
 
+#include <linux/acpi.h>
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
@@ -57,8 +59,13 @@ static int rcpm_pm_prepare(struct device *dev)
 				rcpm->wakeup_cells + 1);
 
 		/*  Wakeup source should refer to current rcpm device */
-		if (ret || (np->phandle != value[0]))
-			continue;
+		if (is_acpi_node(dev->fwnode)) {
+			if (ret)
+				continue;
+		} else {
+			if (ret || (np->phandle != value[0]))
+				continue;
+		}
 
 		/* Property "#fsl,rcpm-wakeup-cells" of rcpm node defines the
 		 * number of IPPDEXPCR register cells, and "fsl,rcpm-wakeup"
@@ -139,10 +146,19 @@ static const struct of_device_id rcpm_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, rcpm_of_match);
 
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id rcpm_acpi_match[] = {
+	{ "NXP0015", },
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, rcpm_acpi_match);
+#endif
+
 static struct platform_driver rcpm_driver = {
 	.driver = {
 		.name = "rcpm",
 		.of_match_table = rcpm_of_match,
+		.acpi_match_table = ACPI_PTR(rcpm_acpi_match),
 		.pm	= &rcpm_pm_ops,
 	},
 	.probe = rcpm_probe,
-- 
2.17.1