[PATCH v2 2/4] fpga: region: introduce compat_id_show op

[trix@xxxxxxxxxx]

From: Tom Rix <trix@xxxxxxxxxx>

The sysfs reported value for compat_id is implementation
dependent.  So add an optional op to fpga_region_ops to allow
an implementation to override the default.

Signed-off-by: Tom Rix <trix@xxxxxxxxxx>
---
 drivers/fpga/fpga-region.c       | 3 +++
 include/linux/fpga/fpga-region.h | 2 ++
 2 files changed, 5 insertions(+)

diff --git a/drivers/fpga/fpga-region.c b/drivers/fpga/fpga-region.c
index dfa35c2dc2720..864dd4f290e3b 100644
--- a/drivers/fpga/fpga-region.c
+++ b/drivers/fpga/fpga-region.c
@@ -169,6 +169,9 @@ static ssize_t compat_id_show(struct device *dev,
 {
 	struct fpga_region *region = to_fpga_region(dev);
 
+	if (region->rops && region->rops->compat_id_show)
+		return region->rops->compat_id_show(region, buf);
+
 	if (!region->compat_id)
 		return -ENOENT;
 
diff --git a/include/linux/fpga/fpga-region.h b/include/linux/fpga/fpga-region.h
index d712344fd00a7..236d3819f1c13 100644
--- a/include/linux/fpga/fpga-region.h
+++ b/include/linux/fpga/fpga-region.h
@@ -12,6 +12,7 @@ struct fpga_region;
 /**
  * struct fpga_region_ops - ops for low level fpga region drivers
  * @get_bridges: optional function to get bridges to a list
+ * @compat_id_show: optional function emit to sysfs a compatible id
  *
  * fpga_region_ops are the low level functions implemented by a specific
  * fpga region driver.  The optional ones are tested for NULL before being
@@ -19,6 +20,7 @@ struct fpga_region;
  */
 struct fpga_region_ops {
 	int (*get_bridges)(struct fpga_region *region);
+	ssize_t (*compat_id_show)(struct fpga_region *region, char *buf);
 };
 
 /**
-- 
2.26.3