[PATCH v7 2/2] fpga: zynqmp-fpga: Adds status interface

[Nava kishore Manne]

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/bus/platform/drivers/zynqmp_fpga_manager/firmware:zynqmp-firmware:pcap/status

Signed-off-by: Nava kishore Manne <nava.kishore.manne at amd.com>
---
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.

Changes for v6:
              - Updated the sysfs interface to cat /sys/bus/platform/drivers/...
                as suggested by Xu Yilun.
              - Exported raw hex value instead of multiple error strings
                as suggested by Greg.

Changes for v7:
              - Fixed some minor issues as suggested by Xu Yilun.

 .../ABI/testing/sysfs-driver-zynqmp-fpga      | 73 +++++++++++++++++++
 drivers/fpga/zynqmp-fpga.c                    | 21 ++++++
 2 files changed, 94 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..8f93d27b6d91
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-driver-zynqmp-fpga
@@ -0,0 +1,73 @@
+What:		/sys/bus/platform/drivers/zynqmp_fpga_manager/firmware:zynqmp-firmware:pcap/status
+Date:		February 2023
+KernelVersion:	6.4
+Contact:	Nava kishore Manne <nava.kishore.manne at amd.com>
+Description:	(RO) Read fpga status.
+		Read returns a hexadecimal value that tells the current status
+		of the FPGA device. Each bit position in the status value is
+		described Below(see ug570 chapter 9).
+		https://docs.xilinx.com/v/u/en-US/ug570-ultrascale-configuration
+
+		======================  ==============================================
+		BIT(0)			0: No CRC error
+					1: CRC error
+
+		BIT(1)			0: Decryptor security not set
+					1: Decryptor security set
+
+		BIT(2)			0: MMCMs/PLLs are not locked
+					1: MMCMs/PLLs are locked
+
+		BIT(3)			0: DCI not matched
+					1: DCI matched
+
+		BIT(4)			0: Start-up sequence has not finished
+					1: Start-up sequence has finished
+
+		BIT(5)			0: All I/Os are placed in High-Z state
+					1: All I/Os behave as configured
+
+		BIT(6)			0: Flip-flops and block RAM are write disabled
+					1: Flip-flops and block RAM are write enabled
+
+		BIT(7)			0: GHIGH_B_STATUS asserted
+					1: GHIGH_B_STATUS deasserted
+
+		BIT(8) to BIT(10)	Status of the mode pins
+
+		BIT(11)			0: Initialization has not finished
+					1: Initialization finished
+
+		BIT(12)			Value on INIT_B_PIN pin
+
+		BIT(13)			0: Signal not released
+					1: Signal released
+
+		BIT(14)			Value on DONE_PIN pin.
+
+		BIT(15)			0: No IDCODE_ERROR
+					1: IDCODE_ERROR
+
+		BIT(16)			0: No SECURITY_ERROR
+					1: SECURITY_ERROR
+
+		BIT(17)			System Monitor over-temperature if set
+
+		BIT(18) to BIT(20)	Start-up state machine (0 to 7)
+					Phase 0 = 000
+					Phase 1 = 001
+					Phase 2 = 011
+					Phase 3 = 010
+					Phase 4 = 110
+					Phase 5 = 111
+					Phase 6 = 101
+					Phase 7 = 100
+
+		BIT(25) to BIT(26)	Indicates the detected bus width
+					00 = x1
+					01 = x8
+					10 = x16
+					11 = x32
+		======================  ==============================================
+
+		The other bits are reserved.
diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
index c60f20949c47..f3434e2c487b 100644
--- a/drivers/fpga/zynqmp-fpga.c
+++ b/drivers/fpga/zynqmp-fpga.c
@@ -77,6 +77,26 @@ 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)
+{
+	u32 status;
+	int ret;
+
+	ret = zynqmp_pm_fpga_get_config_status(&status);
+	if (ret)
+		return ret;
+
+	return sysfs_emit(buf, "0x%x\n", status);
+}
+static DEVICE_ATTR_RO(status);
+
+static struct attribute *zynqmp_fpga_attrs[] = {
+	&dev_attr_status.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(zynqmp_fpga);
+
 static const struct fpga_manager_ops zynqmp_fpga_ops = {
 	.state = zynqmp_fpga_ops_state,
 	.write_init = zynqmp_fpga_ops_write_init,
@@ -113,6 +133,7 @@ static struct platform_driver zynqmp_fpga_driver = {
 	.driver = {
 		.name = "zynqmp_fpga_manager",
 		.of_match_table = of_match_ptr(zynqmp_fpga_of_match),
+		.dev_groups = zynqmp_fpga_groups,
 	},
 };
 
-- 
2.25.1