[PATCH] fpga: region: introduce fpga_region_ops

From: trix
Date: Tue Aug 03 2021 - 13:53:58 EST

From: Tom Rix <trix@xxxxxxxxxx>

Convert passing of a get_bridges() function pointer in the
the *fpga_region_create() to passing an ops table with
get_bridges() as an element.

For backward compatibility, because *create() could take a NULL
function pointer, *create() and take a NULL ops table.

Non NULL uses were converted to ops tables.

Add a fpga_region_get_bridges() wrapper handle to the NULL cases.

Signed-off-by: Tom Rix <trix@xxxxxxxxxx>
---
Documentation/driver-api/fpga/fpga-region.rst | 6 +++-
drivers/fpga/dfl-fme-pr.c | 2 +-
drivers/fpga/dfl-fme-region.c | 6 +++-
drivers/fpga/fpga-region.c | 32 +++++++++++--------
drivers/fpga/of-fpga-region.c | 6 +++-
include/linux/fpga/fpga-region.h | 22 ++++++++++---
6 files changed, 53 insertions(+), 21 deletions(-)

diff --git a/Documentation/driver-api/fpga/fpga-region.rst b/Documentation/driver-api/fpga/fpga-region.rst
index 2636a27c11b24..b18fec6c4be56 100644
--- a/Documentation/driver-api/fpga/fpga-region.rst
+++ b/Documentation/driver-api/fpga/fpga-region.rst
@@ -46,6 +46,7 @@ API to add a new FPGA region
----------------------------

* struct fpga_region - The FPGA region struct
+* struct fpga_region_ops — Low level FPGA region driver ops
* devm_fpga_region_create() - Allocate and init a region struct
* fpga_region_register() - Register an FPGA region
* fpga_region_unregister() - Unregister an FPGA region
@@ -63,7 +64,7 @@ The FPGA region will need to specify which bridges to control while programming
the FPGA. The region driver can build a list of bridges during probe time
(:c:expr:`fpga_region->bridge_list`) or it can have a function that creates
the list of bridges to program just before programming
-(:c:expr:`fpga_region->get_bridges`). The FPGA bridge framework supplies the
+(:c:expr:`fpga_region_ops->get_bridges`). The FPGA bridge framework supplies the
following APIs to handle building or tearing down that list.

* fpga_bridge_get_to_list() - Get a ref of an FPGA bridge, add it to a
@@ -75,6 +76,9 @@ following APIs to handle building or tearing down that list.
.. kernel-doc:: include/linux/fpga/fpga-region.h
:functions: fpga_region

+.. kernel-doc:: include/linux/fpga/fpga-region.h
+ :functions: fpga_region_ops
+
.. kernel-doc:: drivers/fpga/fpga-region.c
:functions: devm_fpga_region_create

diff --git a/drivers/fpga/dfl-fme-pr.c b/drivers/fpga/dfl-fme-pr.c
index d61ce9a188792..4805d8c533d4a 100644
--- a/drivers/fpga/dfl-fme-pr.c
+++ b/drivers/fpga/dfl-fme-pr.c
@@ -151,7 +151,7 @@ static int fme_pr(struct platform_device *pdev, unsigned long arg)
* reenabling the bridge to clear things out between acceleration runs.
* so no need to hold the bridges after partial reconfiguration.
*/
- if (region->get_bridges)
+ if (region->rops && region->rops->get_bridges)
fpga_bridges_put(&region->bridge_list);

put_device(&region->dev);
diff --git a/drivers/fpga/dfl-fme-region.c b/drivers/fpga/dfl-fme-region.c
index 1eeb42af10122..ca7277d3d30a9 100644
--- a/drivers/fpga/dfl-fme-region.c
+++ b/drivers/fpga/dfl-fme-region.c
@@ -27,6 +27,10 @@ static int fme_region_get_bridges(struct fpga_region *region)
return fpga_bridge_get_to_list(dev, region->info, &region->bridge_list);
}

+static const struct fpga_region_ops fme_fpga_region_ops = {
+ .get_bridges = fme_region_get_bridges,
+};
+
static int fme_region_probe(struct platform_device *pdev)
{
struct dfl_fme_region_pdata *pdata = dev_get_platdata(&pdev->dev);
@@ -39,7 +43,7 @@ static int fme_region_probe(struct platform_device *pdev)
if (IS_ERR(mgr))
return -EPROBE_DEFER;

- region = devm_fpga_region_create(dev, mgr, fme_region_get_bridges);
+ region = devm_fpga_region_create(dev, mgr, &fme_fpga_region_ops);
if (!region) {
ret = -ENOMEM;
goto eprobe_mgr_put;
diff --git a/drivers/fpga/fpga-region.c b/drivers/fpga/fpga-region.c
index a4838715221ff..dfa35c2dc2720 100644
--- a/drivers/fpga/fpga-region.c
+++ b/drivers/fpga/fpga-region.c
@@ -18,6 +18,14 @@
static DEFINE_IDA(fpga_region_ida);
static struct class *fpga_region_class;

+static int fpga_region_get_bridges(struct fpga_region *region)
+{
+ if (region->rops && region->rops->get_bridges)
+ return region->rops->get_bridges(region);
+
+ return 0;
+}
+
struct fpga_region *fpga_region_class_find(
struct device *start, const void *data,
int (*match)(struct device *, const void *))
@@ -115,12 +123,10 @@ int fpga_region_program_fpga(struct fpga_region *region)
* In some cases, we already have a list of bridges in the
* fpga region struct. Or we don't have any bridges.
*/
- if (region->get_bridges) {
- ret = region->get_bridges(region);
- if (ret) {
- dev_err(dev, "failed to get fpga region bridges\n");
- goto err_unlock_mgr;
- }
+ ret = fpga_region_get_bridges(region);
+ if (ret) {
+ dev_err(dev, "failed to get fpga region bridges\n");
+ goto err_unlock_mgr;
}

ret = fpga_bridges_disable(&region->bridge_list);
@@ -147,7 +153,7 @@ int fpga_region_program_fpga(struct fpga_region *region)
return 0;

err_put_br:
- if (region->get_bridges)
+ if (region->rops && region->rops->get_bridges)
fpga_bridges_put(&region->bridge_list);
err_unlock_mgr:
fpga_mgr_unlock(region->mgr);
@@ -183,7 +189,7 @@ ATTRIBUTE_GROUPS(fpga_region);
* fpga_region_create - alloc and init a struct fpga_region
* @parent: device parent
* @mgr: manager that programs this region
- * @get_bridges: optional function to get bridges to a list
+ * @rops: optional pointer to struct for fpga region ops
*
* The caller of this function is responsible for freeing the resulting region
* struct with fpga_region_free(). Using devm_fpga_region_create() instead is
@@ -194,7 +200,7 @@ ATTRIBUTE_GROUPS(fpga_region);
struct fpga_region
*fpga_region_create(struct device *parent,
struct fpga_manager *mgr,
- int (*get_bridges)(struct fpga_region *))
+ const struct fpga_region_ops *rops)
{
struct fpga_region *region;
int id, ret = 0;
@@ -208,7 +214,7 @@ struct fpga_region
goto err_free;

region->mgr = mgr;
- region->get_bridges = get_bridges;
+ region->rops = rops;
mutex_init(&region->mutex);
INIT_LIST_HEAD(&region->bridge_list);

@@ -255,7 +261,7 @@ static void devm_fpga_region_release(struct device *dev, void *res)
* devm_fpga_region_create - create and initialize a managed FPGA region struct
* @parent: device parent
* @mgr: manager that programs this region
- * @get_bridges: optional function to get bridges to a list
+ * @rops: optional pointer to struct for fpga region ops
*
* This function is intended for use in an FPGA region driver's probe function.
* After the region driver creates the region struct with
@@ -270,7 +276,7 @@ static void devm_fpga_region_release(struct device *dev, void *res)
struct fpga_region
*devm_fpga_region_create(struct device *parent,
struct fpga_manager *mgr,
- int (*get_bridges)(struct fpga_region *))
+ const struct fpga_region_ops *rops)
{
struct fpga_region **ptr, *region;

@@ -278,7 +284,7 @@ struct fpga_region
if (!ptr)
return NULL;

- region = fpga_region_create(parent, mgr, get_bridges);
+ region = fpga_region_create(parent, mgr, rops);
if (!region) {
devres_free(ptr);
} else {
diff --git a/drivers/fpga/of-fpga-region.c b/drivers/fpga/of-fpga-region.c
index e3c25576b6b9d..2c99605e008a6 100644
--- a/drivers/fpga/of-fpga-region.c
+++ b/drivers/fpga/of-fpga-region.c
@@ -138,6 +138,10 @@ static int of_fpga_region_get_bridges(struct fpga_region *region)
return 0;
}

+static const struct fpga_region_ops of_fpga_region_ops = {
+ .get_bridges = of_fpga_region_get_bridges,
+};
+
/**
* child_regions_with_firmware
* @overlay: device node of the overlay
@@ -405,7 +409,7 @@ static int of_fpga_region_probe(struct platform_device *pdev)
if (IS_ERR(mgr))
return -EPROBE_DEFER;

- region = devm_fpga_region_create(dev, mgr, of_fpga_region_get_bridges);
+ region = devm_fpga_region_create(dev, mgr, &of_fpga_region_ops);
if (!region) {
ret = -ENOMEM;
goto eprobe_mgr_put;
diff --git a/include/linux/fpga/fpga-region.h b/include/linux/fpga/fpga-region.h
index 27cb706275dba..d712344fd00a7 100644
--- a/include/linux/fpga/fpga-region.h
+++ b/include/linux/fpga/fpga-region.h
@@ -7,6 +7,20 @@
#include <linux/fpga/fpga-mgr.h>
#include <linux/fpga/fpga-bridge.h>

+struct fpga_region;
+
+/**
+ * struct fpga_region_ops - ops for low level fpga region drivers
+ * @get_bridges: optional function to get bridges to a list
+ *
+ * fpga_region_ops are the low level functions implemented by a specific
+ * fpga region driver. The optional ones are tested for NULL before being
+ * called, so leaving them out is fine.
+ */
+struct fpga_region_ops {
+ int (*get_bridges)(struct fpga_region *region);
+};
+
/**
* struct fpga_region - FPGA Region structure
* @dev: FPGA Region device
@@ -16,7 +30,7 @@
* @info: FPGA image info
* @compat_id: FPGA region id for compatibility check.
* @priv: private data
- * @get_bridges: optional function to get bridges to a list
+ * @rops: optional pointer to struct for fpga region ops
*/
struct fpga_region {
struct device dev;
@@ -26,7 +40,7 @@ struct fpga_region {
struct fpga_image_info *info;
struct fpga_compat_id *compat_id;
void *priv;
- int (*get_bridges)(struct fpga_region *region);
+ const struct fpga_region_ops *rops;
};

#define to_fpga_region(d) container_of(d, struct fpga_region, dev)
@@ -39,13 +53,13 @@ int fpga_region_program_fpga(struct fpga_region *region);

struct fpga_region
*fpga_region_create(struct device *dev, struct fpga_manager *mgr,
- int (*get_bridges)(struct fpga_region *));
+ const struct fpga_region_ops *rops);
void fpga_region_free(struct fpga_region *region);
int fpga_region_register(struct fpga_region *region);
void fpga_region_unregister(struct fpga_region *region);

struct fpga_region
*devm_fpga_region_create(struct device *dev, struct fpga_manager *mgr,
- int (*get_bridges)(struct fpga_region *));
+ const struct fpga_region_ops *rops);

#endif /* _FPGA_REGION_H */
--
2.26.3