[PATCH v4 25/25] firmware: xilinx: Add sysfs and API to set boot health status

[Jolly Shah]

From: Rajan Vaja <rajan.vaja@xxxxxxxxxx>

Add sysfs interface to set boot health status from user space.
Add API used by this interface to communicate with firmware.

If PMUFW is compiled with CHECK_HEALTHY_BOOT, it will check the
healthy bit on FPD WDT expiration. If healthy bit is set by a user
application running in Linux, PMUFW will do APU only restart. If
healthy bit is not set during FPD WDT expiration, PMUFW will do
system restart.

Signed-off-by: Rajan Vaja <rajan.vaja@xxxxxxxxxx>
Signed-off-by: Michal Simek <michal.simek@xxxxxxxxxx>
Signed-off-by: Tejas Patel <tejas.patel@xxxxxxxxxx>
Signed-off-by: Jolly Shah <jolly.shah@xxxxxxxxxx>
---
 .../ABI/stable/sysfs-driver-firmware-zynqmp        | 21 ++++++++++++
 drivers/firmware/xilinx/zynqmp.c                   | 39 ++++++++++++++++++++++
 include/linux/firmware/xlnx-zynqmp.h               |  7 ++++
 3 files changed, 67 insertions(+)

diff --git a/Documentation/ABI/stable/sysfs-driver-firmware-zynqmp b/Documentation/ABI/stable/sysfs-driver-firmware-zynqmp
index 554f30c..00fa04c 100644
--- a/Documentation/ABI/stable/sysfs-driver-firmware-zynqmp
+++ b/Documentation/ABI/stable/sysfs-driver-firmware-zynqmp
@@ -80,3 +80,24 @@ Description:
 		# echo "subsystem" > /sys/devices/platform/firmware\:zynqmp-firmware/shutdown_scope
 
 Users:		Xilinx
+
+What:		/sys/devices/platform/firmware\:zynqmp-firmware/health_status
+Date:		March 2020
+KernelVersion:	5.6
+Contact:	"Jolly Shah" <jollys@xxxxxxxxxx>
+Description:
+		This sysfs interface allows to set the health status. If PMUFW
+		is compiled with CHECK_HEALTHY_BOOT, it will check the healthy
+		bit on FPD WDT expiration. If healthy bit is set by a user
+		application running in Linux, PMUFW will do APU only restart. If
+		healthy bit is not set during FPD WDT expiration, PMUFW will do
+		system restart.
+
+		Usage:
+		Set healthy bit
+		# echo 1 > /sys/devices/platform/firmware\:zynqmp-firmware/health_status
+
+		Unset healthy bit
+		# echo 0 > /sys/devices/platform/firmware\:zynqmp-firmware/health_status
+
+Users:		Xilinx
diff --git a/drivers/firmware/xilinx/zynqmp.c b/drivers/firmware/xilinx/zynqmp.c
index 8d36618..bfaf29a 100644
--- a/drivers/firmware/xilinx/zynqmp.c
+++ b/drivers/firmware/xilinx/zynqmp.c
@@ -684,6 +684,21 @@ int zynqmp_pm_read_pggs(u32 index, u32 *value)
 EXPORT_SYMBOL_GPL(zynqmp_pm_read_pggs);
 
 /**
+ * zynqmp_pm_set_boot_health_status() - PM API for setting healthy boot status
+ * @value	Status value to be written
+ *
+ * This function sets healthy bit value to indicate boot health status
+ * to firmware.
+ *
+ * @return      Returns status, either success or error+reason
+ */
+int zynqmp_pm_set_boot_health_status(u32 value)
+{
+	return zynqmp_pm_invoke_fn(PM_IOCTL, 0, IOCTL_SET_BOOT_HEALTH_STATUS,
+				   value, 0, NULL);
+}
+
+/**
  * zynqmp_pm_reset_assert - Request setting of reset (1 - assert, 0 - release)
  * @reset:		Reset to be configured
  * @assert_flag:	Flag stating should reset be asserted (1) or
@@ -984,6 +999,29 @@ static ssize_t shutdown_scope_store(struct device *device,
 
 static DEVICE_ATTR_RW(shutdown_scope);
 
+static ssize_t health_status_store(struct device *device,
+				   struct device_attribute *attr,
+				   const char *buf, size_t count)
+{
+	int ret;
+	unsigned int value;
+
+	ret = kstrtouint(buf, 10, &value);
+	if (ret)
+		return ret;
+
+	ret = zynqmp_pm_set_boot_health_status(value);
+	if (ret) {
+		dev_err(device, "unable to set healthy bit value to %u\n",
+			value);
+		return ret;
+	}
+
+	return count;
+}
+
+static DEVICE_ATTR_WO(health_status);
+
 static ssize_t ggs_show(struct device *device,
 			struct device_attribute *attr,
 			char *buf,
@@ -1143,6 +1181,7 @@ static struct attribute *zynqmp_firmware_attrs[] = {
 	&dev_attr_pggs2.attr,
 	&dev_attr_pggs3.attr,
 	&dev_attr_shutdown_scope.attr,
+	&dev_attr_health_status.attr,
 	NULL,
 };
 
diff --git a/include/linux/firmware/xlnx-zynqmp.h b/include/linux/firmware/xlnx-zynqmp.h
index c297333..5968df8 100644
--- a/include/linux/firmware/xlnx-zynqmp.h
+++ b/include/linux/firmware/xlnx-zynqmp.h
@@ -114,6 +114,8 @@ enum pm_ioctl_id {
 	IOCTL_READ_GGS = 13,
 	IOCTL_WRITE_PGGS = 14,
 	IOCTL_READ_PGGS = 15,
+	/* Set healthy bit value */
+	IOCTL_SET_BOOT_HEALTH_STATUS = 17,
 };
 
 enum pm_query_id {
@@ -354,6 +356,7 @@ 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);
+int zynqmp_pm_set_boot_health_status(u32 value);
 #else
 static inline struct zynqmp_eemi_ops *zynqmp_pm_get_eemi_ops(void)
 {
@@ -500,6 +503,10 @@ static inline int zynqmp_pm_system_shutdown(const u32 type, const u32 subtype)
 {
 	return -ENODEV;
 }
+static inline int zynqmp_pm_set_boot_health_status(u32 value)
+{
+	return -ENODEV;
+}
 #endif
 
 #endif /* __FIRMWARE_ZYNQMP_H__ */
-- 
2.7.4