[PATCH] soc: xilinx: Set CAP_UNUSABLE requirement for versal while powering down domain

[Jolly Shah]

From: Tejas Patel <tejas.patel@xxxxxxxxxx>

For "0" requirement which is used to inform firmware that
device is not required currently by master, Versal LibPM disables
clock, power it down and reset the device. genpd_power_off()
is being called during runtime suspend also. So, if any device
goes to runtime suspend state during resumes it needs to be
re-initialized again. It is possible that drivers do not
reinitialize device upon resume from runtime suspend every time.

In LibPM new PM_CAP_UNUSABLE capability is added, which disables
clock only and avoids power down and reset.
So, set CAPABILITY_UNUSABLE requirement during zynqmp_gpd_power_off()
if platform is other than zynqmp.

Signed-off-by: Tejas Patel <tejas.patel@xxxxxxxxxx>
Signed-off-by: Jolly Shah <jollys@xxxxxxxxxx>
---
 drivers/soc/xilinx/zynqmp_pm_domains.c | 10 ++++++++--
 include/linux/firmware/xlnx-zynqmp.h   |  3 ++-
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/soc/xilinx/zynqmp_pm_domains.c b/drivers/soc/xilinx/zynqmp_pm_domains.c
index 600f57c..23d90cb 100644
--- a/drivers/soc/xilinx/zynqmp_pm_domains.c
+++ b/drivers/soc/xilinx/zynqmp_pm_domains.c
@@ -2,7 +2,7 @@
 /*
  * ZynqMP Generic PM domain support
  *
- *  Copyright (C) 2015-2018 Xilinx, Inc.
+ *  Copyright (C) 2015-2019 Xilinx, Inc.
  *
  *  Davorin Mista <davorin.mista@xxxxxxxxxx>
  *  Jolly Shah <jollys@xxxxxxxxxx>
@@ -25,6 +25,8 @@
 
 static const struct zynqmp_eemi_ops *eemi_ops;
 
+static int min_capability;
+
 /**
  * struct zynqmp_pm_domain - Wrapper around struct generic_pm_domain
  * @gpd:		Generic power domain
@@ -106,7 +108,7 @@ static int zynqmp_gpd_power_off(struct generic_pm_domain *domain)
 	int ret;
 	struct pm_domain_data *pdd, *tmp;
 	struct zynqmp_pm_domain *pd;
-	u32 capabilities = 0;
+	u32 capabilities = min_capability;
 	bool may_wakeup;
 
 	if (!eemi_ops->set_requirement)
@@ -283,6 +285,10 @@ static int zynqmp_gpd_probe(struct platform_device *pdev)
 	if (!domains)
 		return -ENOMEM;
 
+	if (!of_device_is_compatible(dev->parent->of_node,
+				     "xlnx,zynqmp-firmware"))
+		min_capability = ZYNQMP_PM_CAPABILITY_UNUSABLE;
+
 	for (i = 0; i < ZYNQMP_NUM_DOMAINS; i++, pd++) {
 		pd->node_id = 0;
 		pd->gpd.name = kasprintf(GFP_KERNEL, "domain%d", i);
diff --git a/include/linux/firmware/xlnx-zynqmp.h b/include/linux/firmware/xlnx-zynqmp.h
index 778abbb..b8a7c22 100644
--- a/include/linux/firmware/xlnx-zynqmp.h
+++ b/include/linux/firmware/xlnx-zynqmp.h
@@ -2,7 +2,7 @@
 /*
  * Xilinx Zynq MPSoC Firmware layer
  *
- *  Copyright (C) 2014-2018 Xilinx
+ *  Copyright (C) 2014-2019 Xilinx
  *
  *  Michal Simek <michal.simek@xxxxxxxxxx>
  *  Davorin Mista <davorin.mista@xxxxxxxxxx>
@@ -46,6 +46,7 @@
 #define	ZYNQMP_PM_CAPABILITY_ACCESS	0x1U
 #define	ZYNQMP_PM_CAPABILITY_CONTEXT	0x2U
 #define	ZYNQMP_PM_CAPABILITY_WAKEUP	0x4U
+#define ZYNQMP_PM_CAPABILITY_UNUSABLE	0x8U
 
 /*
  * Firmware FPGA Manager flags
-- 
2.7.4