[PATCH v3 24/24] 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: Jolly Shah <jollys@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                   | 63 ++++++++++++++++++++++
 include/linux/firmware/xlnx-zynqmp.h               |  3 ++
 3 files changed, 87 insertions(+)

diff --git a/Documentation/ABI/stable/sysfs-driver-firmware-zynqmp b/Documentation/ABI/stable/sysfs-driver-firmware-zynqmp
index b46ec0c..a37b408 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 9caf1cf..fc3aa4e 100644
--- a/drivers/firmware/xilinx/zynqmp.c
+++ b/drivers/firmware/xilinx/zynqmp.c
@@ -667,6 +667,21 @@ 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
@@ -995,6 +1010,53 @@ static const struct attribute_group shutdown_scope_attribute_group = {
 };
 
 /**
+ * health_status_store - Store health_status sysfs attribute
+ * @device:	Device structure
+ * @attr:	Device attribute structure
+ * @buf:	User entered health_status attribute string
+ * @count:	Buffer size
+ *
+ * User-space interface for setting the boot health status.
+ * Usage: echo <value> > /sys/devices/platform/firmware\:zynqmp-firmware/health_status
+ *
+ * Value:
+ *	1 - Set healthy bit to 1
+ *	0 - Unset healthy bit
+ *
+ * Return:	count argument if request succeeds, the corresponding error
+ *		code otherwise
+ */
+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) {
+		pr_err("unable to set healthy bit value to %u\n", value);
+		return ret;
+	}
+
+	return count;
+}
+
+static DEVICE_ATTR_WO(health_status);
+
+static struct attribute *zynqmp_health_status_attrs[] = {
+	&dev_attr_health_status.attr,
+	NULL,
+};
+static const struct attribute_group health_status_attribute_group = {
+	.attrs = zynqmp_health_status_attrs,
+};
+
+/**
  * ggs_show - Show global general storage (ggs) sysfs attribute
  * @device: Device structure
  * @attr: Device attribute structure
@@ -1307,6 +1369,7 @@ static const struct attribute_group ggs_attribute_group = {
 const struct attribute_group *firmware_attribute_groups[] = {
 	&ggs_attribute_group,
 	&shutdown_scope_attribute_group,
+	&health_status_attribute_group,
 	NULL,
 };
 
diff --git a/include/linux/firmware/xlnx-zynqmp.h b/include/linux/firmware/xlnx-zynqmp.h
index 31ed58c..1900349 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,
 	IOCTL_WRITE_PGGS,
 	IOCTL_READ_PGGS,
+	/* Set healthy bit value */
+	IOCTL_SET_BOOT_HEALTH_STATUS = 17,
 };
 
 enum pm_query_id {
@@ -341,6 +343,7 @@ 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);
 int zynqmp_pm_invoke_fn(u32 pm_api_id, u32 arg0, u32 arg1,
 			u32 arg2, u32 arg3, u32 *ret_payload);
 
-- 
2.7.4