[PATCH v5 2/2] fpga: zynqmp-fpga: Adds status interface

From: Nava kishore Manne
Date: Tue Jan 31 2023 - 04:49:08 EST

Adds status interface for zynqmp-fpga, It's a read only interface
which allows the user to get the Programmable Logic(PL) configuration
status.

Usage:
To read the Programmable Logic(PL) configuration status
cat /sys/class/fpga_manager/<fpga>/device/status

Signed-off-by: Nava kishore Manne <nava.kishore.manne@xxxxxxx>
---
Changes for v2:
- Updated status messages handling logic as suggested by Xu Yilun.

Changes for v3:
- Updated status interface handling logic (Restrict the status
interface to the device-specific instead of handled by the core)
as suggested by Xu Yilun.

Changes for v4:
- Limit the error strings to one word for each as suggested by
Xu Yilun

Changes for v5:
- Added new sysfs-driver-zynqmp-fpga file.

.../ABI/testing/sysfs-driver-zynqmp-fpga | 18 ++++
drivers/fpga/zynqmp-fpga.c | 87 +++++++++++++++++++
2 files changed, 105 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-driver-zynqmp-fpga

diff --git a/Documentation/ABI/testing/sysfs-driver-zynqmp-fpga b/Documentation/ABI/testing/sysfs-driver-zynqmp-fpga
new file mode 100644
index 000000000000..66c98bb8dfba
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-driver-zynqmp-fpga
@@ -0,0 +1,18 @@
+What: /sys/class/fpga_manager/<fpga>/device/status
+Date: Jan 2023
+KernelVersion: 6.2
+Contact: Nava kishore Manne <nava.kishore.manne@xxxxxxx>
+Description: Read fpga status as a string.
+ If FPGA programming operation fails, it could be caused by crc
+ error or incompatible bitstream image. The intent of this
+ interface is to provide more detailed information for FPGA
+ programming errors to userspace. This is a list of strings for
+ the supported status.
+
+ * CRC-Error - CRC error detected by hardware.
+ * Security-Error - Security error detected by hardware.
+ * Initialization-Error - Device Initialization error.
+ * Internal-Signal-Error - Device internal signal error.
+ * I/Os-High-Z-state - All I/Os are placed in High-Z state.
+ * Sequence-Error - Device start-up sequence error.
+ * Firmware-Error - Firmware error.
diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
index c60f20949c47..81d3e18527ee 100644
--- a/drivers/fpga/zynqmp-fpga.c
+++ b/drivers/fpga/zynqmp-fpga.c
@@ -15,6 +15,37 @@
/* Constant Definitions */
#define IXR_FPGA_DONE_MASK BIT(3)

+/* Error Register */
+#define IXR_FPGA_ERR_CRC_ERR BIT(0)
+#define IXR_FPGA_ERR_SECURITY_ERR BIT(16)
+
+/* Signal Status Register */
+#define IXR_FPGA_END_OF_STARTUP BIT(4)
+#define IXR_FPGA_GST_CFG_B BIT(5)
+#define IXR_FPGA_INIT_B_INTERNAL BIT(11)
+#define IXR_FPGA_DONE_INTERNAL_SIGNAL BIT(13)
+
+/* FPGA error status. */
+enum {
+ ZYNQMP_FPGA_STATUS_CRC_ERR,
+ ZYNQMP_FPGA_STATUS_SECURITY_ERR,
+ ZYNQMP_FPGA_STATUS_DEVICE_INIT_ERR,
+ ZYNQMP_FPGA_STATUS_SIGNAL_ERR,
+ ZYNQMP_FPGA_STATUS_HIGH_Z_STATE_ERR,
+ ZYNQMP_FPGA_STATUS_EOS_ERR,
+ ZYNQMP_FPGA_MGR_STATUS_FIRMWARE_REQ_ERR,
+};
+
+static const char * const zynqmp_fpga_error_statuses[] = {
+ [ZYNQMP_FPGA_STATUS_CRC_ERR] = "CRC-Error",
+ [ZYNQMP_FPGA_STATUS_SECURITY_ERR] = "Security-Error",
+ [ZYNQMP_FPGA_STATUS_DEVICE_INIT_ERR] = "Initialization-Error",
+ [ZYNQMP_FPGA_STATUS_SIGNAL_ERR] = "Internal-Signal-Error",
+ [ZYNQMP_FPGA_STATUS_HIGH_Z_STATE_ERR] = "I/Os-High-Z-state",
+ [ZYNQMP_FPGA_STATUS_EOS_ERR] = "Sequence-Error",
+ [ZYNQMP_FPGA_MGR_STATUS_FIRMWARE_REQ_ERR] = "Firmware-Error",
+};
+
/**
* struct zynqmp_fpga_priv - Private data structure
* @dev: Device data structure
@@ -77,6 +108,54 @@ static enum fpga_mgr_states zynqmp_fpga_ops_state(struct fpga_manager *mgr)
return FPGA_MGR_STATE_UNKNOWN;
}

+static ssize_t status_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ unsigned long status = 0;
+ ssize_t len = 0;
+ u32 reg_val;
+ int ret;
+ u8 i;
+
+ ret = zynqmp_pm_fpga_get_config_status(&reg_val);
+ if (!ret) {
+ if (reg_val & IXR_FPGA_ERR_CRC_ERR)
+ status |= ZYNQMP_FPGA_STATUS_CRC_ERR;
+ if (reg_val & IXR_FPGA_ERR_SECURITY_ERR)
+ status |= ZYNQMP_FPGA_STATUS_SECURITY_ERR;
+ if (!(reg_val & IXR_FPGA_INIT_B_INTERNAL))
+ status |= ZYNQMP_FPGA_STATUS_DEVICE_INIT_ERR;
+ if (!(reg_val & IXR_FPGA_DONE_INTERNAL_SIGNAL))
+ status |= ZYNQMP_FPGA_STATUS_SIGNAL_ERR;
+ if (!(reg_val & IXR_FPGA_GST_CFG_B))
+ status |= ZYNQMP_FPGA_STATUS_HIGH_Z_STATE_ERR;
+ if (!(reg_val & IXR_FPGA_END_OF_STARTUP))
+ status |= ZYNQMP_FPGA_STATUS_EOS_ERR;
+ } else {
+ status = ZYNQMP_FPGA_MGR_STATUS_FIRMWARE_REQ_ERR;
+ }
+
+ for_each_set_bit(i, &status, ARRAY_SIZE(zynqmp_fpga_error_statuses))
+ len += sysfs_emit_at(buf, len, "%s ",
+ zynqmp_fpga_error_statuses[i]);
+
+ if (len)
+ buf[len - 1] = '\n';
+
+ return len;
+}
+
+static DEVICE_ATTR_RO(status);
+
+static struct attribute *zynqmp_fpga_device_attrs[] = {
+ &dev_attr_status.attr,
+ NULL,
+};
+
+static const struct attribute_group zynqmp_fpga_attr_group = {
+ .attrs = zynqmp_fpga_device_attrs,
+};
+
static const struct fpga_manager_ops zynqmp_fpga_ops = {
.state = zynqmp_fpga_ops_state,
.write_init = zynqmp_fpga_ops_write_init,
@@ -88,6 +167,7 @@ static int zynqmp_fpga_probe(struct platform_device *pdev)
struct device *dev = &pdev->dev;
struct zynqmp_fpga_priv *priv;
struct fpga_manager *mgr;
+ int ret;

priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
@@ -95,6 +175,13 @@ static int zynqmp_fpga_probe(struct platform_device *pdev)

priv->dev = dev;

+ /* Add the device attributes */
+ ret = sysfs_create_group(&dev->kobj, &zynqmp_fpga_attr_group);
+ if (ret) {
+ dev_err(dev, "Error creating sysfs files\n");
+ return ret;
+ }
+
mgr = devm_fpga_mgr_register(dev, "Xilinx ZynqMP FPGA Manager",
&zynqmp_fpga_ops, priv);
return PTR_ERR_OR_ZERO(mgr);
--
2.25.1