Linux Kernels

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

This change “soc: xilinx: Set CAP_UNUSABLE requirement for versal while powering down domain” (commit e502ff8) in Linux kernel is authored by Tejas Patel <tejas.patel [at] xilinx.com> on Mon Aug 26 13:30:44 2019 -0700.

Description of "soc: xilinx: Set CAP_UNUSABLE requirement for versal while powering down domain"

The change “soc: xilinx: Set CAP_UNUSABLE requirement for versal while powering down domain” introduces changes as follows.

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

For "0" requirement which is used to inform firmware that device is
not required currently by master, Versal PLM (Platform Loader and
Manager) which runs on Platform Management Controller and is responsible
platform management of devices that 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 ans so dont want it to be powered down or get reset
during runtime suspend.

In Versal PLM new PM_CAP_UNUSABLE capability is added, which disables
clock only and avoids power down and reset during runtime suspend. Power
and reset will be gated with core suspend.So, this patch sets
CAPABILITY_UNUSABLE requirement during gpd_power_off()
if platform is other than zynqmp.

Signed-off-by: Tejas Patel <tejas.patel@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

Linux kernel releases containing commit e502ff8

The Linux kernel releases containing this commit are as follows.

Linux kernel code changes in "soc: xilinx: Set CAP_UNUSABLE requirement for versal while powering down domain"

There are 13 lines of Linux source code added/deleted in this change. Code changes to Linux kernel are as follows.

 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 600f57cf0c2e..23d90cb12ba9 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@aggios.com>
  *  Jolly Shah <jollys@xilinx.com>
@@ -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 778abbbc7d94..adb14bcedca2 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@xilinx.com>
  *  Davorin Mista <davorin.mista@aggios.com>
@@ -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

The commit for this change in Linux stable tree is e502ff8 (patch).

Last modified: 2020/01/11 06:53