fpga: mgr: add status for fpga-manager

This patch adds status sysfs interface for fpga manager, it's a
read only interface which allows user to get fpga manager status,
including full/partial reconfiguration error and other status
information. It adds a status callback to fpga_manager_ops too,
allows each fpga_manager driver to define its own method to
collect latest status from hardware.

The following sysfs file is created:
* /sys/class/fpga_manager/<fpga>/status
  Return status of fpga manager, including reconfiguration errors.

Signed-off-by: Wu Hao <hao.wu@intel.com>
Acked-by: Alan Tull <atull@kernel.org>
Acked-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
index c1564cf..a41b07e 100644
--- a/drivers/fpga/fpga-mgr.c
+++ b/drivers/fpga/fpga-mgr.c
@@ -406,12 +406,40 @@ static ssize_t state_show(struct device *dev,
 	return sprintf(buf, "%s\n", state_str[mgr->state]);
 }
 
+static ssize_t status_show(struct device *dev,
+			   struct device_attribute *attr, char *buf)
+{
+	struct fpga_manager *mgr = to_fpga_manager(dev);
+	u64 status;
+	int len = 0;
+
+	if (!mgr->mops->status)
+		return -ENOENT;
+
+	status = mgr->mops->status(mgr);
+
+	if (status & FPGA_MGR_STATUS_OPERATION_ERR)
+		len += sprintf(buf + len, "reconfig operation error\n");
+	if (status & FPGA_MGR_STATUS_CRC_ERR)
+		len += sprintf(buf + len, "reconfig CRC error\n");
+	if (status & FPGA_MGR_STATUS_INCOMPATIBLE_IMAGE_ERR)
+		len += sprintf(buf + len, "reconfig incompatible image\n");
+	if (status & FPGA_MGR_STATUS_IP_PROTOCOL_ERR)
+		len += sprintf(buf + len, "reconfig IP protocol error\n");
+	if (status & FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR)
+		len += sprintf(buf + len, "reconfig fifo overflow error\n");
+
+	return len;
+}
+
 static DEVICE_ATTR_RO(name);
 static DEVICE_ATTR_RO(state);
+static DEVICE_ATTR_RO(status);
 
 static struct attribute *fpga_mgr_attrs[] = {
 	&dev_attr_name.attr,
 	&dev_attr_state.attr,
+	&dev_attr_status.attr,
 	NULL,
 };
 ATTRIBUTE_GROUPS(fpga_mgr);