Merge tag 'fpga-for-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mdf/linux-fpga into char-misc-next

Moritz writes:

Here is the first set of changes for the 5.10-rc1 merge window.

Xilinx:
- Luca's changes clean up the xilinx-spi driver and add better
  diagnostics on errors.

Core:
- I cleaned up a stray comment.
- Richard's change marks FPGA manager tasks un-interruptible.
- Tom has agreed to help out as Reviewer in the FPGA Manager subsystem.

DFL:
- Xu's changes  add a new bus that is the first part of a series to support
  adding devices via DFL (the other parts are still under review)

All patches have been reviewed on the mailing list, and have been in the
last few linux-next releases (as part of my for-next branch) without issues.

Signed-off-by: Moritz Fischer <mdf@kernel.org>

* tag 'fpga-for-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mdf/linux-fpga:
  fpga: dfl: create a dfl bus type to support DFL devices
  fpga: fpga-region: Cleanup an outdated comment
  fpga: dfl: map feature mmio resources in their own feature drivers
  fpga manager: xilinx-spi: provide better diagnostics on programming failure
  fpga manager: xilinx-spi: add error checking after gpiod_get_value()
  fpga manager: xilinx-spi: fix write_complete timeout handling
  fpga manager: xilinx-spi: remove final dot from dev_err() strings
  fpga manager: xilinx-spi: remove stray comment
  fpga: dfl: change data type of feature id to u16
  MAINTAINERS: Add Tom Rix as fpga reviewer
  fpga: stratix10-soc: make FPGA task un-interruptible

9 files changed, 583 insertions, 143 deletions

diff --git a/Documentation/ABI/testing/sysfs-bus-dfl b/Documentation/ABI/testing/sysfs-bus-dfl
new file mode 100644
index 000000000000..23543be904f2
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-dfl
@@ -0,0 +1,15 @@
+What:		/sys/bus/dfl/devices/dfl_dev.X/type
+Date:		Aug 2020
+KernelVersion:	5.10
+Contact:	Xu Yilun <yilun.xu@intel.com>
+Description:	Read-only. It returns type of DFL FIU of the device. Now DFL
+		supports 2 FIU types, 0 for FME, 1 for PORT.
+		Format: 0x%x
+
+What:		/sys/bus/dfl/devices/dfl_dev.X/feature_id
+Date:		Aug 2020
+KernelVersion:	5.10
+Contact:	Xu Yilun <yilun.xu@intel.com>
+Description:	Read-only. It returns feature identifier local to its DFL FIU
+		type.
+		Format: 0x%x
diff --git a/MAINTAINERS b/MAINTAINERS
index 3edf55b9954c..286fd7263982 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6828,14 +6828,17 @@ F:	drivers/net/ethernet/nvidia/*
 
 FPGA DFL DRIVERS
 M:	Wu Hao <hao.wu@intel.com>
+R:	Tom Rix <trix@redhat.com>
 L:	linux-fpga@vger.kernel.org
 S:	Maintained
+F:	Documentation/ABI/testing/sysfs-bus-dfl
 F:	Documentation/fpga/dfl.rst
 F:	drivers/fpga/dfl*
 F:	include/uapi/linux/fpga-dfl.h
 
 FPGA MANAGER FRAMEWORK
 M:	Moritz Fischer <mdf@kernel.org>
+R:	Tom Rix <trix@redhat.com>
 L:	linux-fpga@vger.kernel.org
 S:	Maintained
 W:	http://www.rocketboards.org
diff --git a/drivers/fpga/dfl-fme-perf.c b/drivers/fpga/dfl-fme-perf.c
index 6ce1ed222ea4..531266287eee 100644
--- a/drivers/fpga/dfl-fme-perf.c
+++ b/drivers/fpga/dfl-fme-perf.c
@@ -148,7 +148,7 @@ struct fme_perf_priv {
 	struct device *dev;
 	void __iomem *ioaddr;
 	struct pmu pmu;
-	u64 id;
+	u16 id;
 
 	u32 fab_users;
 	u32 fab_port_id;
diff --git a/drivers/fpga/dfl-pci.c b/drivers/fpga/dfl-pci.c
index e220bec2927d..a2203d03c9e2 100644
--- a/drivers/fpga/dfl-pci.c
+++ b/drivers/fpga/dfl-pci.c
@@ -31,12 +31,12 @@ struct cci_drvdata {
 	struct dfl_fpga_cdev *cdev;	/* container device */
 };
 
-static void __iomem *cci_pci_ioremap_bar(struct pci_dev *pcidev, int bar)
+static void __iomem *cci_pci_ioremap_bar0(struct pci_dev *pcidev)
 {
-	if (pcim_iomap_regions(pcidev, BIT(bar), DRV_NAME))
+	if (pcim_iomap_regions(pcidev, BIT(0), DRV_NAME))
 		return NULL;
 
-	return pcim_iomap_table(pcidev)[bar];
+	return pcim_iomap_table(pcidev)[0];
 }
 
 static int cci_pci_alloc_irq(struct pci_dev *pcidev)
@@ -156,8 +156,8 @@ static int cci_enumerate_feature_devs(struct pci_dev *pcidev)
 			goto irq_free_exit;
 	}
 
-	/* start to find Device Feature List from Bar 0 */
-	base = cci_pci_ioremap_bar(pcidev, 0);
+	/* start to find Device Feature List in Bar 0 */
+	base = cci_pci_ioremap_bar0(pcidev);
 	if (!base) {
 		ret = -ENOMEM;
 		goto irq_free_exit;
@@ -172,7 +172,7 @@ static int cci_enumerate_feature_devs(struct pci_dev *pcidev)
 		start = pci_resource_start(pcidev, 0);
 		len = pci_resource_len(pcidev, 0);
 
-		dfl_fpga_enum_info_add_dfl(info, start, len, base);
+		dfl_fpga_enum_info_add_dfl(info, start, len);
 
 		/*
 		 * find more Device Feature Lists (e.g. Ports) per information
@@ -196,26 +196,24 @@ static int cci_enumerate_feature_devs(struct pci_dev *pcidev)
 			 */
 			bar = FIELD_GET(FME_PORT_OFST_BAR_ID, v);
 			offset = FIELD_GET(FME_PORT_OFST_DFH_OFST, v);
-			base = cci_pci_ioremap_bar(pcidev, bar);
-			if (!base)
-				continue;
-
 			start = pci_resource_start(pcidev, bar) + offset;
 			len = pci_resource_len(pcidev, bar) - offset;
 
-			dfl_fpga_enum_info_add_dfl(info, start, len,
-						   base + offset);
+			dfl_fpga_enum_info_add_dfl(info, start, len);
 		}
 	} else if (dfl_feature_is_port(base)) {
 		start = pci_resource_start(pcidev, 0);
 		len = pci_resource_len(pcidev, 0);
 
-		dfl_fpga_enum_info_add_dfl(info, start, len, base);
+		dfl_fpga_enum_info_add_dfl(info, start, len);
 	} else {
 		ret = -ENODEV;
 		goto irq_free_exit;
 	}
 
+	/* release I/O mappings for next step enumeration */
+	pcim_iounmap_regions(pcidev, BIT(0));
+
 	/* start enumeration with prepared enumeration information */
 	cdev = dfl_fpga_feature_devs_enumerate(info);
 	if (IS_ERR(cdev)) {
diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
index 649958a36e62..b450870b75ed 100644
--- a/drivers/fpga/dfl.c
+++ b/drivers/fpga/dfl.c
@@ -30,12 +30,6 @@ static DEFINE_MUTEX(dfl_id_mutex);
  * index to dfl_chardevs table. If no chardev support just set devt_type
  * as one invalid index (DFL_FPGA_DEVT_MAX).
  */
-enum dfl_id_type {
-	FME_ID,		/* fme id allocation and mapping */
-	PORT_ID,	/* port id allocation and mapping */
-	DFL_ID_MAX,
-};
-
 enum dfl_fpga_devt_type {
 	DFL_FPGA_DEVT_FME,
 	DFL_FPGA_DEVT_PORT,
@@ -58,7 +52,7 @@ static const char *dfl_pdata_key_strings[DFL_ID_MAX] = {
  */
 struct dfl_dev_info {
 	const char *name;
-	u32 dfh_id;
+	u16 dfh_id;
 	struct idr id;
 	enum dfl_fpga_devt_type devt_type;
 };
@@ -134,7 +128,7 @@ static enum dfl_id_type feature_dev_id_type(struct platform_device *pdev)
 	return DFL_ID_MAX;
 }
 
-static enum dfl_id_type dfh_id_to_type(u32 id)
+static enum dfl_id_type dfh_id_to_type(u16 id)
 {
 	int i;
 
@@ -250,6 +244,249 @@ int dfl_fpga_check_port_id(struct platform_device *pdev, void *pport_id)
 }
 EXPORT_SYMBOL_GPL(dfl_fpga_check_port_id);
 
+static DEFINE_IDA(dfl_device_ida);
+
+static const struct dfl_device_id *
+dfl_match_one_device(const struct dfl_device_id *id, struct dfl_device *ddev)
+{
+	if (id->type == ddev->type && id->feature_id == ddev->feature_id)
+		return id;
+
+	return NULL;
+}
+
+static int dfl_bus_match(struct device *dev, struct device_driver *drv)
+{
+	struct dfl_device *ddev = to_dfl_dev(dev);
+	struct dfl_driver *ddrv = to_dfl_drv(drv);
+	const struct dfl_device_id *id_entry;
+
+	id_entry = ddrv->id_table;
+	if (id_entry) {
+		while (id_entry->feature_id) {
+			if (dfl_match_one_device(id_entry, ddev)) {
+				ddev->id_entry = id_entry;
+				return 1;
+			}
+			id_entry++;
+		}
+	}
+
+	return 0;
+}
+
+static int dfl_bus_probe(struct device *dev)
+{
+	struct dfl_driver *ddrv = to_dfl_drv(dev->driver);
+	struct dfl_device *ddev = to_dfl_dev(dev);
+
+	return ddrv->probe(ddev);
+}
+
+static int dfl_bus_remove(struct device *dev)
+{
+	struct dfl_driver *ddrv = to_dfl_drv(dev->driver);
+	struct dfl_device *ddev = to_dfl_dev(dev);
+
+	if (ddrv->remove)
+		ddrv->remove(ddev);
+
+	return 0;
+}
+
+static int dfl_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+	struct dfl_device *ddev = to_dfl_dev(dev);
+
+	/* The type has 4 valid bits and feature_id has 12 valid bits */
+	return add_uevent_var(env, "MODALIAS=dfl:t%01Xf%03X",
+			      ddev->type, ddev->feature_id);
+}
+
+static ssize_t
+type_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct dfl_device *ddev = to_dfl_dev(dev);
+
+	return sprintf(buf, "0x%x\n", ddev->type);
+}
+static DEVICE_ATTR_RO(type);
+
+static ssize_t
+feature_id_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct dfl_device *ddev = to_dfl_dev(dev);
+
+	return sprintf(buf, "0x%x\n", ddev->feature_id);
+}
+static DEVICE_ATTR_RO(feature_id);
+
+static struct attribute *dfl_dev_attrs[] = {
+	&dev_attr_type.attr,
+	&dev_attr_feature_id.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(dfl_dev);
+
+static struct bus_type dfl_bus_type = {
+	.name		= "dfl",
+	.match		= dfl_bus_match,
+	.probe		= dfl_bus_probe,
+	.remove		= dfl_bus_remove,
+	.uevent		= dfl_bus_uevent,
+	.dev_groups	= dfl_dev_groups,
+};
+
+static void release_dfl_dev(struct device *dev)
+{
+	struct dfl_device *ddev = to_dfl_dev(dev);
+
+	if (ddev->mmio_res.parent)
+		release_resource(&ddev->mmio_res);
+
+	ida_simple_remove(&dfl_device_ida, ddev->id);
+	kfree(ddev->irqs);
+	kfree(ddev);
+}
+
+static struct dfl_device *
+dfl_dev_add(struct dfl_feature_platform_data *pdata,
+	    struct dfl_feature *feature)
+{
+	struct platform_device *pdev = pdata->dev;
+	struct resource *parent_res;
+	struct dfl_device *ddev;
+	int id, i, ret;
+
+	ddev = kzalloc(sizeof(*ddev), GFP_KERNEL);
+	if (!ddev)
+		return ERR_PTR(-ENOMEM);
+
+	id = ida_simple_get(&dfl_device_ida, 0, 0, GFP_KERNEL);
+	if (id < 0) {
+		dev_err(&pdev->dev, "unable to get id\n");
+		kfree(ddev);
+		return ERR_PTR(id);
+	}
+
+	/* freeing resources by put_device() after device_initialize() */
+	device_initialize(&ddev->dev);
+	ddev->dev.parent = &pdev->dev;
+	ddev->dev.bus = &dfl_bus_type;
+	ddev->dev.release = release_dfl_dev;
+	ddev->id = id;
+	ret = dev_set_name(&ddev->dev, "dfl_dev.%d", id);
+	if (ret)
+		goto put_dev;
+
+	ddev->type = feature_dev_id_type(pdev);
+	ddev->feature_id = feature->id;
+	ddev->cdev = pdata->dfl_cdev;
+
+	/* add mmio resource */
+	parent_res = &pdev->resource[feature->resource_index];
+	ddev->mmio_res.flags = IORESOURCE_MEM;
+	ddev->mmio_res.start = parent_res->start;
+	ddev->mmio_res.end = parent_res->end;
+	ddev->mmio_res.name = dev_name(&ddev->dev);
+	ret = insert_resource(parent_res, &ddev->mmio_res);
+	if (ret) {
+		dev_err(&pdev->dev, "%s failed to claim resource: %pR\n",
+			dev_name(&ddev->dev), &ddev->mmio_res);
+		goto put_dev;
+	}
+
+	/* then add irq resource */
+	if (feature->nr_irqs) {
+		ddev->irqs = kcalloc(feature->nr_irqs,
+				     sizeof(*ddev->irqs), GFP_KERNEL);
+		if (!ddev->irqs) {
+			ret = -ENOMEM;
+			goto put_dev;
+		}
+
+		for (i = 0; i < feature->nr_irqs; i++)
+			ddev->irqs[i] = feature->irq_ctx[i].irq;
+
+		ddev->num_irqs = feature->nr_irqs;
+	}
+
+	ret = device_add(&ddev->dev);
+	if (ret)
+		goto put_dev;
+
+	dev_dbg(&pdev->dev, "add dfl_dev: %s\n", dev_name(&ddev->dev));
+	return ddev;
+
+put_dev:
+	/* calls release_dfl_dev() which does the clean up  */
+	put_device(&ddev->dev);
+	return ERR_PTR(ret);
+}
+
+static void dfl_devs_remove(struct dfl_feature_platform_data *pdata)
+{
+	struct dfl_feature *feature;
+
+	dfl_fpga_dev_for_each_feature(pdata, feature) {
+		if (feature->ddev) {
+			device_unregister(&feature->ddev->dev);
+			feature->ddev = NULL;
+		}
+	}
+}
+
+static int dfl_devs_add(struct dfl_feature_platform_data *pdata)
+{
+	struct dfl_feature *feature;
+	struct dfl_device *ddev;
+	int ret;
+
+	dfl_fpga_dev_for_each_feature(pdata, feature) {
+		if (feature->ioaddr)
+			continue;
+
+		if (feature->ddev) {
+			ret = -EEXIST;
+			goto err;
+		}
+
+		ddev = dfl_dev_add(pdata, feature);
+		if (IS_ERR(ddev)) {
+			ret = PTR_ERR(ddev);
+			goto err;
+		}
+
+		feature->ddev = ddev;
+	}
+
+	return 0;
+
+err:
+	dfl_devs_remove(pdata);
+	return ret;
+}
+
+int __dfl_driver_register(struct dfl_driver *dfl_drv, struct module *owner)
+{
+	if (!dfl_drv || !dfl_drv->probe || !dfl_drv->id_table)
+		return -EINVAL;
+
+	dfl_drv->drv.owner = owner;
+	dfl_drv->drv.bus = &dfl_bus_type;
+
+	return driver_register(&dfl_drv->drv);
+}
+EXPORT_SYMBOL(__dfl_driver_register);
+
+void dfl_driver_unregister(struct dfl_driver *dfl_drv)
+{
+	driver_unregister(&dfl_drv->drv);
+}
+EXPORT_SYMBOL(dfl_driver_unregister);
+
+#define is_header_feature(feature) ((feature)->id == FEATURE_ID_FIU_HEADER)
+
 /**
  * dfl_fpga_dev_feature_uinit - uinit for sub features of dfl feature device
  * @pdev: feature device.
@@ -259,12 +496,15 @@ void dfl_fpga_dev_feature_uinit(struct platform_device *pdev)
 	struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev->dev);
 	struct dfl_feature *feature;
 
-	dfl_fpga_dev_for_each_feature(pdata, feature)
+	dfl_devs_remove(pdata);
+
+	dfl_fpga_dev_for_each_feature(pdata, feature) {
 		if (feature->ops) {
 			if (feature->ops->uinit)
 				feature->ops->uinit(pdev, feature);
 			feature->ops = NULL;
 		}
+	}
 }
 EXPORT_SYMBOL_GPL(dfl_fpga_dev_feature_uinit);
 
@@ -273,8 +513,22 @@ static int dfl_feature_instance_init(struct platform_device *pdev,
 				     struct dfl_feature *feature,
 				     struct dfl_feature_driver *drv)
 {
+	void __iomem *base;
 	int ret = 0;
 
+	if (!is_header_feature(feature)) {
+		base = devm_platform_ioremap_resource(pdev,
+						      feature->resource_index);
+		if (IS_ERR(base)) {
+			dev_err(&pdev->dev,
+				"ioremap failed for feature 0x%x!\n",
+				feature->id);
+			return PTR_ERR(base);
+		}
+
+		feature->ioaddr = base;
+	}
+
 	if (drv->ops->init) {
 		ret = drv->ops->init(pdev, feature);
 		if (ret)
@@ -331,6 +585,10 @@ int dfl_fpga_dev_feature_init(struct platform_device *pdev,
 		drv++;
 	}
 
+	ret = dfl_devs_add(pdata);
+	if (ret)
+		goto exit;
+
 	return 0;
 exit:
 	dfl_fpga_dev_feature_uinit(pdev);
@@ -427,7 +685,9 @@ EXPORT_SYMBOL_GPL(dfl_fpga_dev_ops_unregister);
  * @irq_table: Linux IRQ numbers for all irqs, indexed by local irq index of
  *	       this device.
  * @feature_dev: current feature device.
- * @ioaddr: header register region address of feature device in enumeration.
+ * @ioaddr: header register region address of current FIU in enumeration.
+ * @start: register resource start of current FIU.
+ * @len: max register resource length of current FIU.
  * @sub_features: a sub features linked list for feature device in enumeration.
  * @feature_num: number of sub features for feature device in enumeration.
  */
@@ -439,6 +699,8 @@ struct build_feature_devs_info {
 
 	struct platform_device *feature_dev;
 	void __iomem *ioaddr;
+	resource_size_t start;
+	resource_size_t len;
 	struct list_head sub_features;
 	int feature_num;
 };
@@ -454,7 +716,7 @@ struct build_feature_devs_info {
  * @nr_irqs: number of irqs of this sub feature.
  */
 struct dfl_feature_info {
-	u64 fid;
+	u16 fid;
 	struct resource mmio_res;
 	void __iomem *ioaddr;
 	struct list_head node;
@@ -484,10 +746,7 @@ static int build_info_commit_dev(struct build_feature_devs_info *binfo)
 	struct dfl_feature_platform_data *pdata;
 	struct dfl_feature_info *finfo, *p;
 	enum dfl_id_type type;
-	int ret, index = 0;
-
-	if (!fdev)
-		return 0;
+	int ret, index = 0, res_idx = 0;
 
 	type = feature_dev_id_type(fdev);
 	if (WARN_ON_ONCE(type >= DFL_ID_MAX))
@@ -530,16 +789,32 @@ static int build_info_commit_dev(struct build_feature_devs_info *binfo)
 
 	/* fill features and resource information for feature dev */
 	list_for_each_entry_safe(finfo, p, &binfo->sub_features, node) {
-		struct dfl_feature *feature = &pdata->features[index];
+		struct dfl_feature *feature = &pdata->features[index++];
 		struct dfl_feature_irq_ctx *ctx;
 		unsigned int i;
 
 		/* save resource information for each feature */
 		feature->dev = fdev;
 		feature->id = finfo->fid;
-		feature->resource_index = index;
-		feature->ioaddr = finfo->ioaddr;
-		fdev->resource[index++] = finfo->mmio_res;
+
+		/*
+		 * the FIU header feature has some fundamental functions (sriov
+		 * set, port enable/disable) needed for the dfl bus device and
+		 * other sub features. So its mmio resource should be mapped by
+		 * DFL bus device. And we should not assign it to feature
+		 * devices (dfl-fme/afu) again.
+		 */
+		if (is_header_feature(feature)) {
+			feature->resource_index = -1;
+			feature->ioaddr =
+				devm_ioremap_resource(binfo->dev,
+						      &finfo->mmio_res);
+			if (IS_ERR(feature->ioaddr))
+				return PTR_ERR(feature->ioaddr);
+		} else {
+			feature->resource_index = res_idx;
+			fdev->resource[res_idx++] = finfo->mmio_res;
+		}
 
 		if (finfo->nr_irqs) {
 			ctx = devm_kcalloc(binfo->dev, finfo->nr_irqs,
@@ -582,19 +857,13 @@ static int build_info_commit_dev(struct build_feature_devs_info *binfo)
 
 static int
 build_info_create_dev(struct build_feature_devs_info *binfo,
-		      enum dfl_id_type type, void __iomem *ioaddr)
+		      enum dfl_id_type type)
 {
 	struct platform_device *fdev;
-	int ret;
 
 	if (type >= DFL_ID_MAX)
 		return -EINVAL;
 
-	/* we will create a new device, commit current device first */
-	ret = build_info_commit_dev(binfo);
-	if (ret)
-		return ret;
-
 	/*
 	 * we use -ENODEV as the initialization indicator which indicates
 	 * whether the id need to be reclaimed
@@ -605,7 +874,7 @@ build_info_create_dev(struct build_feature_devs_info *binfo,
 
 	binfo->feature_dev = fdev;
 	binfo->feature_num = 0;
-	binfo->ioaddr = ioaddr;
+
 	INIT_LIST_HEAD(&binfo->sub_features);
 
 	fdev->id = dfl_id_alloc(type, &fdev->dev);
@@ -649,7 +918,7 @@ static inline u32 feature_size(void __iomem *start)
 	return ofst ? ofst : 4096;
 }
 
-static u64 feature_id(void __iomem *start)
+static u16 feature_id(void __iomem *start)
 {
 	u64 v = readq(start + DFH);
 	u16 id = FIELD_GET(DFH_ID, v);
@@ -667,7 +936,7 @@ static u64 feature_id(void __iomem *start)
 }
 
 static int parse_feature_irqs(struct build_feature_devs_info *binfo,
-			      resource_size_t ofst, u64 fid,
+			      resource_size_t ofst, u16 fid,
 			      unsigned int *irq_base, unsigned int *nr_irqs)
 {
 	void __iomem *base = binfo->ioaddr + ofst;
@@ -713,12 +982,12 @@ static int parse_feature_irqs(struct build_feature_devs_info *binfo,
 		return 0;
 	}
 
-	dev_dbg(binfo->dev, "feature: 0x%llx, irq_base: %u, nr_irqs: %u\n",
+	dev_dbg(binfo->dev, "feature: 0x%x, irq_base: %u, nr_irqs: %u\n",
 		fid, ibase, inr);
 
 	if (ibase + inr > binfo->nr_irqs) {
 		dev_err(binfo->dev,
-			"Invalid interrupt number in feature 0x%llx\n", fid);
+			"Invalid interrupt number in feature 0x%x\n", fid);
 		return -EINVAL;
 	}
 
@@ -726,7 +995,7 @@ static int parse_feature_irqs(struct build_feature_devs_info *binfo,
 		virq = binfo->irq_table[ibase + i];
 		if (virq < 0 || virq > NR_IRQS) {
 			dev_err(binfo->dev,
-				"Invalid irq table entry for feature 0x%llx\n",
+				"Invalid irq table entry for feature 0x%x\n",
 				fid);
 			return -EINVAL;
 		}
@@ -747,18 +1016,17 @@ static int parse_feature_irqs(struct build_feature_devs_info *binfo,
  */
 static int
 create_feature_instance(struct build_feature_devs_info *binfo,
-			struct dfl_fpga_enum_dfl *dfl, resource_size_t ofst,
-			resource_size_t size, u64 fid)
+			resource_size_t ofst, resource_size_t size, u16 fid)
 {
 	unsigned int irq_base, nr_irqs;
 	struct dfl_feature_info *finfo;
 	int ret;
 
 	/* read feature size and id if inputs are invalid */
-	size = size ? size : feature_size(dfl->ioaddr + ofst);
-	fid = fid ? fid : feature_id(dfl->ioaddr + ofst);
+	size = size ? size : feature_size(binfo->ioaddr + ofst);
+	fid = fid ? fid : feature_id(binfo->ioaddr + ofst);
 
-	if (dfl->len - ofst < size)
+	if (binfo->len - ofst < size)
 		return -EINVAL;
 
 	ret = parse_feature_irqs(binfo, ofst, fid, &irq_base, &nr_irqs);
@@ -770,12 +1038,11 @@ create_feature_instance(struct build_feature_devs_info *binfo,
 		return -ENOMEM;
 
 	finfo->fid = fid;
-	finfo->mmio_res.start = dfl->start + ofst;
+	finfo->mmio_res.start = binfo->start + ofst;
 	finfo->mmio_res.end = finfo->mmio_res.start + size - 1;
 	finfo->mmio_res.flags = IORESOURCE_MEM;
 	finfo->irq_base = irq_base;
 	finfo->nr_irqs = nr_irqs;
-	finfo->ioaddr = dfl->ioaddr + ofst;
 
 	list_add_tail(&finfo->node, &binfo->sub_features);
 	binfo->feature_num++;
@@ -784,7 +1051,6 @@ create_feature_instance(struct build_feature_devs_info *binfo,
 }
 
 static int parse_feature_port_afu(struct build_feature_devs_info *binfo,
-				  struct dfl_fpga_enum_dfl *dfl,
 				  resource_size_t ofst)
 {
 	u64 v = readq(binfo->ioaddr + PORT_HDR_CAP);
@@ -792,21 +1058,22 @@ static int parse_feature_port_afu(struct build_feature_devs_info *binfo,
 
 	WARN_ON(!size);
 
-	return create_feature_instance(binfo, dfl, ofst, size, FEATURE_ID_AFU);
+	return create_feature_instance(binfo, ofst, size, FEATURE_ID_AFU);
 }
 
+#define is_feature_dev_detected(binfo) (!!(binfo)->feature_dev)
+
 static int parse_feature_afu(struct build_feature_devs_info *binfo,
-			     struct dfl_fpga_enum_dfl *dfl,
 			     resource_size_t ofst)
 {
-	if (!binfo->feature_dev) {
+	if (!is_feature_dev_detected(binfo)) {
 		dev_err(binfo->dev, "this AFU does not belong to any FIU.\n");
 		return -EINVAL;
 	}
 
 	switch (feature_dev_id_type(binfo->feature_dev)) {
 	case PORT_ID:
-		return parse_feature_port_afu(binfo, dfl, ofst);
+		return parse_feature_port_afu(binfo, ofst);
 	default:
 		dev_info(binfo->dev, "AFU belonging to FIU %s is not supported yet.\n",
 			 binfo->feature_dev->name);
@@ -815,35 +1082,79 @@ static int parse_feature_afu(struct build_feature_devs_info *binfo,
 	return 0;
 }
 
+static int build_info_prepare(struct build_feature_devs_info *binfo,
+			      resource_size_t start, resource_size_t len)
+{
+	struct device *dev = binfo->dev;
+	void __iomem *ioaddr;
+
+	if (!devm_request_mem_region(dev, start, len, dev_name(dev))) {
+		dev_err(dev, "request region fail, start:%pa, len:%pa\n",
+			&start, &len);
+		return -EBUSY;
+	}
+
+	ioaddr = devm_ioremap(dev, start, len);
+	if (!ioaddr) {
+		dev_err(dev, "ioremap region fail, start:%pa, len:%pa\n",
+			&start, &len);
+		return -ENOMEM;
+	}
+
+	binfo->start = start;
+	binfo->len = len;
+	binfo->ioaddr = ioaddr;
+
+	return 0;
+}
+
+static void build_info_complete(struct build_feature_devs_info *binfo)
+{
+	devm_iounmap(binfo->dev, binfo->ioaddr);
+	devm_release_mem_region(binfo->dev, binfo->start, binfo->len);
+}
+
 static int parse_feature_fiu(struct build_feature_devs_info *binfo,
-			     struct dfl_fpga_enum_dfl *dfl,
 			     resource_size_t ofst)
 {
-	u32 id, offset;
-	u64 v;
 	int ret = 0;
+	u32 offset;
+	u16 id;
+	u64 v;
+
+	if (is_feature_dev_detected(binfo)) {
+		build_info_complete(binfo);
+
+		ret = build_info_commit_dev(binfo);
+		if (ret)
+			return ret;
 
-	v = readq(dfl->ioaddr + ofst + DFH);
+		ret = build_info_prepare(binfo, binfo->start + ofst,
+					 binfo->len - ofst);
+		if (ret)
+			return ret;
+	}
+
+	v = readq(binfo->ioaddr + DFH);
 	id = FIELD_GET(DFH_ID, v);
 
 	/* create platform device for dfl feature dev */
-	ret = build_info_create_dev(binfo, dfh_id_to_type(id),
-				    dfl->ioaddr + ofst);
+	ret = build_info_create_dev(binfo, dfh_id_to_type(id));
 	if (ret)
 		return ret;
 
-	ret = create_feature_instance(binfo, dfl, ofst, 0, 0);
+	ret = create_feature_instance(binfo, 0, 0, 0);
 	if (ret)
 		return ret;
 	/*
 	 * find and parse FIU's child AFU via its NEXT_AFU register.
 	 * please note that only Port has valid NEXT_AFU pointer per spec.
 	 */
-	v = readq(dfl->ioaddr + ofst + NEXT_AFU);
+	v = readq(binfo->ioaddr + NEXT_AFU);
 
 	offset = FIELD_GET(NEXT_AFU_NEXT_DFH_OFST, v);
 	if (offset)
-		return parse_feature_afu(binfo, dfl, ofst + offset);
+		return parse_feature_afu(binfo, offset);
 
 	dev_dbg(binfo->dev, "No AFUs detected on FIU %d\n", id);
 
@@ -851,41 +1162,39 @@ static int parse_feature_fiu(struct build_feature_devs_info *binfo,
 }
 
 static int parse_feature_private(struct build_feature_devs_info *binfo,
-				 struct dfl_fpga_enum_dfl *dfl,
 				 resource_size_t ofst)
 {
-	if (!binfo->feature_dev) {
-		dev_err(binfo->dev, "the private feature %llx does not belong to any AFU.\n",
-			(unsigned long long)feature_id(dfl->ioaddr + ofst));
+	if (!is_feature_dev_detected(binfo)) {
+		dev_err(binfo->dev, "the private feature 0x%x does not belong to any AFU.\n",
+			feature_id(binfo->ioaddr + ofst));
 		return -EINVAL;
 	}
 
-	return create_feature_instance(binfo, dfl, ofst, 0, 0);
+	return create_feature_instance(binfo, ofst, 0, 0);
 }
 
 /**
  * parse_feature - parse a feature on given device feature list
  *
  * @binfo: build feature devices information.
- * @dfl: device feature list to parse
- * @ofst: offset to feature header on this device feature list
+ * @ofst: offset to current FIU header
  */
 static int parse_feature(struct build_feature_devs_info *binfo,
-			 struct dfl_fpga_enum_dfl *dfl, resource_size_t ofst)
+			 resource_size_t ofst)
 {
 	u64 v;
 	u32 type;
 
-	v = readq(dfl->ioaddr + ofst + DFH);
+	v = readq(binfo->ioaddr + ofst + DFH);
 	type = FIELD_GET(DFH_TYPE, v);
 
 	switch (type) {
 	case DFH_TYPE_AFU:
-		return parse_feature_afu(binfo, dfl, ofst);
+		return parse_feature_afu(binfo, ofst);
 	case DFH_TYPE_PRIVATE:
-		return parse_feature_private(binfo, dfl, ofst);
+		return parse_feature_private(binfo, ofst);
 	case DFH_TYPE_FIU:
-		return parse_feature_fiu(binfo, dfl, ofst);
+		return parse_feature_fiu(binfo, ofst);
 	default:
 		dev_info(binfo->dev,
 			 "Feature Type %x is not supported.\n", type);
@@ -895,14 +1204,17 @@ static int parse_feature(struct build_feature_devs_info *binfo,
 }
 
 static int parse_feature_list(struct build_feature_devs_info *binfo,
-			      struct dfl_fpga_enum_dfl *dfl)
+			      resource_size_t start, resource_size_t len)
 {
-	void __iomem *start = dfl->ioaddr;
-	void __iomem *end = dfl->ioaddr + dfl->len;
+	resource_size_t end = start + len;
 	int ret = 0;
 	u32 ofst = 0;
 	u64 v;
 
+	ret = build_info_prepare(binfo, start, len);
+	if (ret)
+		return ret;
+
 	/* walk through the device feature list via DFH's next DFH pointer. */
 	for (; start < end; start += ofst) {
 		if (end - start < DFH_SIZE) {
@@ -910,11 +1222,11 @@ static int parse_feature_list(struct build_feature_devs_info *binfo,
 			return -EINVAL;
 		}
 
-		ret = parse_feature(binfo, dfl, start - dfl->ioaddr);
+		ret = parse_feature(binfo, start - binfo->start);
 		if (ret)
 			return ret;
 
-		v = readq(start + DFH);
+		v = readq(binfo->ioaddr + start - binfo->start + DFH);
 		ofst = FIELD_GET(DFH_NEXT_HDR_OFST, v);
 
 		/* stop parsing if EOL(End of List) is set or offset is 0 */
@@ -923,7 +1235,12 @@ static int parse_feature_list(struct build_feature_devs_info *binfo,
 	}
 
 	/* commit current feature device when reach the end of list */
-	return build_info_commit_dev(binfo);
+	build_info_complete(binfo);
+
+	if (is_feature_dev_detected(binfo))
+		ret = build_info_commit_dev(binfo);
+
+	return ret;
 }
 
 struct dfl_fpga_enum_info *dfl_fpga_enum_info_alloc(struct device *dev)
@@ -976,7 +1293,6 @@ EXPORT_SYMBOL_GPL(dfl_fpga_enum_info_free);
  * @info: ptr to dfl_fpga_enum_info
  * @start: mmio resource address of the device feature list.
  * @len: mmio resource length of the device feature list.
- * @ioaddr: mapped mmio resource address of the device feature list.
  *
  * One FPGA device may have one or more Device Feature Lists (DFLs), use this
  * function to add information of each DFL to common data structure for next
@@ -985,8 +1301,7 @@ EXPORT_SYMBOL_GPL(dfl_fpga_enum_info_free);
  * Return: 0 on success, negative error code otherwise.
  */
 int dfl_fpga_enum_info_add_dfl(struct dfl_fpga_enum_info *info,
-			       resource_size_t start, resource_size_t len,
-			       void __iomem *ioaddr)
+			       resource_size_t start, resource_size_t len)
 {
 	struct dfl_fpga_enum_dfl *dfl;
 
@@ -996,7 +1311,6 @@ int dfl_fpga_enum_info_add_dfl(struct dfl_fpga_enum_info *info,
 
 	dfl->start = start;
 	dfl->len = len;
-	dfl->ioaddr = ioaddr;
 
 	list_add_tail(&dfl->node, &info->dfls);
 
@@ -1119,7 +1433,7 @@ dfl_fpga_feature_devs_enumerate(struct dfl_fpga_enum_info *info)
 	 * Lists.
 	 */
 	list_for_each_entry(dfl, &info->dfls, node) {
-		ret = parse_feature_list(binfo, dfl);
+		ret = parse_feature_list(binfo, dfl->start, dfl->len);
 		if (ret) {
 			remove_feature_devs(cdev);
 			build_info_free(binfo);
@@ -1212,11 +1526,17 @@ static int __init dfl_fpga_init(void)
 {
 	int ret;
 
+	ret = bus_register(&dfl_bus_type);
+	if (ret)
+		return ret;
+
 	dfl_ids_init();
 
 	ret = dfl_chardev_init();
-	if (ret)
+	if (ret) {
 		dfl_ids_destroy();
+		bus_unregister(&dfl_bus_type);
+	}
 
 	return ret;
 }
@@ -1424,7 +1744,7 @@ static int do_set_irq_trigger(struct dfl_feature *feature, unsigned int idx,
 		return 0;
 
 	feature->irq_ctx[idx].name =
-		kasprintf(GFP_KERNEL, "fpga-irq[%u](%s-%llx)", idx,
+		kasprintf(GFP_KERNEL, "fpga-irq[%u](%s-%x)", idx,
 			  dev_name(&pdev->dev), feature->id);
 	if (!feature->irq_ctx[idx].name)
 		return -ENOMEM;
@@ -1554,6 +1874,7 @@ static void __exit dfl_fpga_exit(void)
 {
 	dfl_chardev_uinit();
 	dfl_ids_destroy();
+	bus_unregister(&dfl_bus_type);
 }
 
 module_init(dfl_fpga_init);
diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h
index a32dfba2a88b..5dc758f655b7 100644
--- a/drivers/fpga/dfl.h
+++ b/drivers/fpga/dfl.h
@@ -197,7 +197,7 @@ int dfl_fpga_check_port_id(struct platform_device *pdev, void *pport_id);
  * @id: unique dfl private feature id.
  */
 struct dfl_feature_id {
-	u64 id;
+	u16 id;
 };
 
 /**
@@ -236,16 +236,18 @@ struct dfl_feature_irq_ctx {
  * @irq_ctx: interrupt context list.
  * @nr_irqs: number of interrupt contexts.
  * @ops: ops of this sub feature.
+ * @ddev: ptr to the dfl device of this sub feature.
  * @priv: priv data of this feature.
  */
 struct dfl_feature {
 	struct platform_device *dev;
-	u64 id;
+	u16 id;
 	int resource_index;
 	void __iomem *ioaddr;
 	struct dfl_feature_irq_ctx *irq_ctx;
 	unsigned int nr_irqs;
 	const struct dfl_feature_ops *ops;
+	struct dfl_device *ddev;
 	void *priv;
 };
 
@@ -365,7 +367,7 @@ struct platform_device *dfl_fpga_inode_to_feature_dev(struct inode *inode)
 	   (feature) < (pdata)->features + (pdata)->num; (feature)++)
 
 static inline
-struct dfl_feature *dfl_get_feature_by_id(struct device *dev, u64 id)
+struct dfl_feature *dfl_get_feature_by_id(struct device *dev, u16 id)
 {
 	struct dfl_feature_platform_data *pdata = dev_get_platdata(dev);
 	struct dfl_feature *feature;
@@ -378,7 +380,7 @@ struct dfl_feature *dfl_get_feature_by_id(struct device *dev, u64 id)
 }
 
 static inline
-void __iomem *dfl_get_feature_ioaddr_by_id(struct device *dev, u64 id)
+void __iomem *dfl_get_feature_ioaddr_by_id(struct device *dev, u16 id)
 {
 	struct dfl_feature *feature = dfl_get_feature_by_id(dev, id);
 
@@ -389,7 +391,7 @@ void __iomem *dfl_get_feature_ioaddr_by_id(struct device *dev, u64 id)
 	return NULL;
 }
 
-static inline bool is_dfl_feature_present(struct device *dev, u64 id)
+static inline bool is_dfl_feature_present(struct device *dev, u16 id)
 {
 	return !!dfl_get_feature_ioaddr_by_id(dev, id);
 }
@@ -441,22 +443,17 @@ struct dfl_fpga_enum_info {
  *
  * @start: base address of this device feature list.
  * @len: size of this device feature list.
- * @ioaddr: mapped base address of this device feature list.
  * @node: node in list of device feature lists.
  */
 struct dfl_fpga_enum_dfl {
 	resource_size_t start;
 	resource_size_t len;
-
-	void __iomem *ioaddr;
-
 	struct list_head node;
 };
 
 struct dfl_fpga_enum_info *dfl_fpga_enum_info_alloc(struct device *dev);
 int dfl_fpga_enum_info_add_dfl(struct dfl_fpga_enum_info *info,
-			       resource_size_t start, resource_size_t len,
-			       void __iomem *ioaddr);
+			       resource_size_t start, resource_size_t len);
 int dfl_fpga_enum_info_add_irq(struct dfl_fpga_enum_info *info,
 			       unsigned int nr_irqs, int *irq_table);
 void dfl_fpga_enum_info_free(struct dfl_fpga_enum_info *info);
@@ -519,4 +516,88 @@ long dfl_feature_ioctl_set_irq(struct platform_device *pdev,
 			       struct dfl_feature *feature,
 			       unsigned long arg);
 
+/**
+ * enum dfl_id_type - define the DFL FIU types
+ */
+enum dfl_id_type {
+	FME_ID,
+	PORT_ID,
+	DFL_ID_MAX,
+};
+
+/**
+ * struct dfl_device_id -  dfl device identifier
+ * @type: contains 4 bits DFL FIU type of the device. See enum dfl_id_type.
+ * @feature_id: contains 12 bits feature identifier local to its DFL FIU type.
+ * @driver_data: driver specific data.
+ */
+struct dfl_device_id {
+	u8 type;
+	u16 feature_id;
+	unsigned long driver_data;
+};
+
+/**
+ * struct dfl_device - represent an dfl device on dfl bus
+ *
+ * @dev: generic device interface.
+ * @id: id of the dfl device.
+ * @type: type of DFL FIU of the device. See enum dfl_id_type.
+ * @feature_id: 16 bits feature identifier local to its DFL FIU type.
+ * @mmio_res: mmio resource of this dfl device.
+ * @irqs: list of Linux IRQ numbers of this dfl device.
+ * @num_irqs: number of IRQs supported by this dfl device.
+ * @cdev: pointer to DFL FPGA container device this dfl device belongs to.
+ * @id_entry: matched id entry in dfl driver's id table.
+ */
+struct dfl_device {
+	struct device dev;
+	int id;
+	u8 type;
+	u16 feature_id;
+	struct resource mmio_res;
+	int *irqs;
+	unsigned int num_irqs;
+	struct dfl_fpga_cdev *cdev;
+	const struct dfl_device_id *id_entry;
+};
+
+/**
+ * struct dfl_driver - represent an dfl device driver
+ *
+ * @drv: driver model structure.
+ * @id_table: pointer to table of device IDs the driver is interested in.
+ *	      { } member terminated.
+ * @probe: mandatory callback for device binding.
+ * @remove: callback for device unbinding.
+ */
+struct dfl_driver {
+	struct device_driver drv;
+	const struct dfl_device_id *id_table;
+
+	int (*probe)(struct dfl_device *dfl_dev);
+	void (*remove)(struct dfl_device *dfl_dev);
+};
+
+#define to_dfl_dev(d) container_of(d, struct dfl_device, dev)
+#define to_dfl_drv(d) container_of(d, struct dfl_driver, drv)
+
+/*
+ * use a macro to avoid include chaining to get THIS_MODULE.
+ */
+#define dfl_driver_register(drv) \
+	__dfl_driver_register(drv, THIS_MODULE)
+int __dfl_driver_register(struct dfl_driver *dfl_drv, struct module *owner);
+void dfl_driver_unregister(struct dfl_driver *dfl_drv);
+
+/*
+ * module_dfl_driver() - Helper macro for drivers that don't do
+ * anything special in module init/exit.  This eliminates a lot of
+ * boilerplate.  Each module may only use this macro once, and
+ * calling it replaces module_init() and module_exit().
+ */
+#define module_dfl_driver(__dfl_driver) \
+	module_driver(__dfl_driver, dfl_driver_register, \
+		      dfl_driver_unregister)
+
 #endif /* __FPGA_DFL_H */
diff --git a/drivers/fpga/fpga-region.c b/drivers/fpga/fpga-region.c
index bde5a9d460c5..c3134b89c3fe 100644
--- a/drivers/fpga/fpga-region.c
+++ b/drivers/fpga/fpga-region.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * FPGA Region - Device Tree support for FPGA programming under Linux
+ * FPGA Region - Support for FPGA programming under Linux
  *
  *  Copyright (C) 2013-2016 Altera Corporation
  *  Copyright (C) 2017 Intel Corporation
diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
index 44b7c569d4dc..657a70c5fc99 100644
--- a/drivers/fpga/stratix10-soc.c
+++ b/drivers/fpga/stratix10-soc.c
@@ -196,17 +196,13 @@ static int s10_ops_write_init(struct fpga_manager *mgr,
 	if (ret < 0)
 		goto init_done;
 
-	ret = wait_for_completion_interruptible_timeout(
+	ret = wait_for_completion_timeout(
 		&priv->status_return_completion, S10_RECONFIG_TIMEOUT);
 	if (!ret) {
 		dev_err(dev, "timeout waiting for RECONFIG_REQUEST\n");
 		ret = -ETIMEDOUT;
 		goto init_done;
 	}
-	if (ret < 0) {
-		dev_err(dev, "error (%d) waiting for RECONFIG_REQUEST\n", ret);
-		goto init_done;
-	}
 
 	ret = 0;
 	if (!test_and_clear_bit(SVC_STATUS_OK, &priv->status)) {
@@ -318,7 +314,7 @@ static int s10_ops_write(struct fpga_manager *mgr, const char *buf,
 		 */
 		wait_status = 1; /* not timed out */
 		if (!priv->status)
-			wait_status = wait_for_completion_interruptible_timeout(
+			wait_status = wait_for_completion_timeout(
 				&priv->status_return_completion,
 				S10_BUFFER_TIMEOUT);
 
@@ -340,13 +336,6 @@ static int s10_ops_write(struct fpga_manager *mgr, const char *buf,
 			ret = -ETIMEDOUT;
 			break;
 		}
-		if (wait_status < 0) {
-			ret = wait_status;
-			dev_err(dev,
-				"error (%d) waiting for svc layer buffers\n",
-				ret);
-			break;
-		}
 	}
 
 	if (!s10_free_buffers(mgr))
@@ -372,7 +361,7 @@ static int s10_ops_write_complete(struct fpga_manager *mgr,
 		if (ret < 0)
 			break;
 
-		ret = wait_for_completion_interruptible_timeout(
+		ret = wait_for_completion_timeout(
 			&priv->status_return_completion, timeout);
 		if (!ret) {
 			dev_err(dev,
@@ -380,12 +369,6 @@ static int s10_ops_write_complete(struct fpga_manager *mgr,
 			ret = -ETIMEDOUT;
 			break;
 		}
-		if (ret < 0) {
-			dev_err(dev,
-				"error (%d) waiting for RECONFIG_COMPLETED\n",
-				ret);
-			break;
-		}
 		/* Not error or timeout, so ret is # of jiffies until timeout */
 		timeout = ret;
 		ret = 0;
diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
index 2967aa2a74e2..824abbbd631e 100644
--- a/drivers/fpga/xilinx-spi.c
+++ b/drivers/fpga/xilinx-spi.c
@@ -27,11 +27,22 @@ struct xilinx_spi_conf {
 	struct gpio_desc *done;
 };
 
-static enum fpga_mgr_states xilinx_spi_state(struct fpga_manager *mgr)
+static int get_done_gpio(struct fpga_manager *mgr)
 {
 	struct xilinx_spi_conf *conf = mgr->priv;
+	int ret;
+
+	ret = gpiod_get_value(conf->done);
+
+	if (ret < 0)
+		dev_err(&mgr->dev, "Error reading DONE (%d)\n", ret);
+
+	return ret;
+}
 
-	if (!gpiod_get_value(conf->done))
+static enum fpga_mgr_states xilinx_spi_state(struct fpga_manager *mgr)
+{
+	if (!get_done_gpio(mgr))
 		return FPGA_MGR_STATE_RESET;
 
 	return FPGA_MGR_STATE_UNKNOWN;
@@ -57,11 +68,21 @@ static int wait_for_init_b(struct fpga_manager *mgr, int value,
 
 	if (conf->init_b) {
 		while (time_before(jiffies, timeout)) {
-			/* dump_state(conf, "wait for init_d .."); */
-			if (gpiod_get_value(conf->init_b) == value)
+			int ret = gpiod_get_value(conf->init_b);
+
+			if (ret == value)
 				return 0;
+
+			if (ret < 0) {
+				dev_err(&mgr->dev, "Error reading INIT_B (%d)\n", ret);
+				return ret;
+			}
+
 			usleep_range(100, 400);
 		}
+
+		dev_err(&mgr->dev, "Timeout waiting for INIT_B to %s\n",
+			value ? "assert" : "deassert");
 		return -ETIMEDOUT;
 	}
 
@@ -78,7 +99,7 @@ static int xilinx_spi_write_init(struct fpga_manager *mgr,
 	int err;
 
 	if (info->flags & FPGA_MGR_PARTIAL_RECONFIG) {
-		dev_err(&mgr->dev, "Partial reconfiguration not supported.\n");
+		dev_err(&mgr->dev, "Partial reconfiguration not supported\n");
 		return -EINVAL;
 	}
 
@@ -86,7 +107,6 @@ static int xilinx_spi_write_init(struct fpga_manager *mgr,
 
 	err = wait_for_init_b(mgr, 1, 1); /* min is 500 ns */
 	if (err) {
-		dev_err(&mgr->dev, "INIT_B pin did not go low\n");
 		gpiod_set_value(conf->prog_b, 0);
 		return err;
 	}
@@ -94,12 +114,10 @@ static int xilinx_spi_write_init(struct fpga_manager *mgr,
 	gpiod_set_value(conf->prog_b, 0);
 
 	err = wait_for_init_b(mgr, 0, 0);
-	if (err) {
-		dev_err(&mgr->dev, "INIT_B pin did not go high\n");
+	if (err)
 		return err;
-	}
 
-	if (gpiod_get_value(conf->done)) {
+	if (get_done_gpio(mgr)) {
 		dev_err(&mgr->dev, "Unexpected DONE pin state...\n");
 		return -EIO;
 	}
@@ -152,25 +170,46 @@ static int xilinx_spi_write_complete(struct fpga_manager *mgr,
 				     struct fpga_image_info *info)
 {
 	struct xilinx_spi_conf *conf = mgr->priv;
-	unsigned long timeout;
+	unsigned long timeout = jiffies + usecs_to_jiffies(info->config_complete_timeout_us);
+	bool expired = false;
+	int done;
 	int ret;
 
-	if (gpiod_get_value(conf->done))
-		return xilinx_spi_apply_cclk_cycles(conf);
+	/*
+	 * This loop is carefully written such that if the driver is
+	 * scheduled out for more than 'timeout', we still check for DONE
+	 * before giving up and we apply 8 extra CCLK cycles in all cases.
+	 */
+	while (!expired) {
+		expired = time_after(jiffies, timeout);
 
-	timeout = jiffies + usecs_to_jiffies(info->config_complete_timeout_us);
-
-	while (time_before(jiffies, timeout)) {
+		done = get_done_gpio(mgr);
+		if (done < 0)
+			return done;
 
 		ret = xilinx_spi_apply_cclk_cycles(conf);
 		if (ret)
 			return ret;
 
-		if (gpiod_get_value(conf->done))
-			return xilinx_spi_apply_cclk_cycles(conf);
+		if (done)
+			return 0;
+	}
+
+	if (conf->init_b) {
+		ret = gpiod_get_value(conf->init_b);
+
+		if (ret < 0) {
+			dev_err(&mgr->dev, "Error reading INIT_B (%d)\n", ret);
+			return ret;
+		}
+
+		dev_err(&mgr->dev,
+			ret ? "CRC error or invalid device\n"
+			: "Missing sync word or incomplete bitstream\n");
+	} else {
+		dev_err(&mgr->dev, "Timeout after config data transfer\n");
 	}
 
-	dev_err(&mgr->dev, "Timeout after config data transfer.\n");
 	return -ETIMEDOUT;
 }