[PATCH v2 3/3] 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 PL status.

Usage:
To read the PL configuration status
        cat /sys/class/fpga_manager/<fpga>/status

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

 drivers/fpga/zynqmp-fpga.c | 53 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
index c60f20949c47..e194bba91d3f 100644
--- a/drivers/fpga/zynqmp-fpga.c
+++ b/drivers/fpga/zynqmp-fpga.c
@@ -14,6 +14,19 @@
 
 /* Constant Definitions */
 #define IXR_FPGA_DONE_MASK	BIT(3)
+#define READ_DMA_SIZE		256U
+
+/* Error Register */
+#define IXR_FPGA_ERR_CRC_ERR		BIT(0)
+#define IXR_FPGA_ERR_SECURITY_ERR	BIT(16)
+
+/* Signal Status Register. For details refer ug570 */
+#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)
+
+#define IXR_FPGA_CONFIG_STAT_OFFSET	7U
 
 /**
  * struct zynqmp_fpga_priv - Private data structure
@@ -77,8 +90,48 @@ static enum fpga_mgr_states zynqmp_fpga_ops_state(struct fpga_manager *mgr)
 	return FPGA_MGR_STATE_UNKNOWN;
 }
 
+static ssize_t zynqmp_fpga_ops_status(struct fpga_manager *mgr, char *buf)
+{
+	unsigned int *kbuf, reg_val;
+	dma_addr_t dma_addr;
+	ssize_t len = 0;
+	int ret;
+
+	kbuf = dma_alloc_coherent(mgr->dev.parent, READ_DMA_SIZE,
+				  &dma_addr, GFP_KERNEL);
+	if (!kbuf)
+		return -ENOMEM;
+
+	ret = zynqmp_pm_fpga_read(IXR_FPGA_CONFIG_STAT_OFFSET, dma_addr,
+				  PM_FPGA_READ_CONFIG_REG, &reg_val);
+	if (ret) {
+		len += sprintf(buf + len, "firmware error\n");
+		goto free_dmabuf;
+	}
+
+	if (reg_val & IXR_FPGA_ERR_CRC_ERR)
+		len += sprintf(buf + len, "reconfig CRC error\n");
+	if (reg_val & IXR_FPGA_ERR_SECURITY_ERR)
+		len += sprintf(buf + len, "reconfig security error\n");
+	if (!(reg_val & IXR_FPGA_INIT_B_INTERNAL))
+		len += sprintf(buf + len, "Device Initialization error\n");
+	if (!(reg_val & IXR_FPGA_DONE_INTERNAL_SIGNAL))
+		len += sprintf(buf + len, "Device internal signal error\n");
+	if (!(reg_val & IXR_FPGA_GST_CFG_B))
+		len += sprintf(buf + len,
+			       "All I/Os are placed in High-Z state\n");
+	if (!(reg_val & IXR_FPGA_END_OF_STARTUP))
+		len += sprintf(buf + len, "Device sequence error\n");
+
+free_dmabuf:
+	dma_free_coherent(mgr->dev.parent, READ_DMA_SIZE, buf, dma_addr);
+
+	return len;
+}
+
 static const struct fpga_manager_ops zynqmp_fpga_ops = {
 	.state = zynqmp_fpga_ops_state,
+	.status = zynqmp_fpga_ops_status,
 	.write_init = zynqmp_fpga_ops_write_init,
 	.write = zynqmp_fpga_ops_write,
 };
-- 
2.25.1