[PATCH v2 11/16] fpga: region: separate out code that parses the overlay

Alan Tull
2017-04-20T14:10:52Z

New function of_fpga_region_parse_ov added, moving code
from fpga_region_notify_pre_apply. This function
gets the FPGA image info from the overlay and is able
to simplify some of the logic involved.

This is a baby step in refactoring the FPGA region code to
separate out common code from Device Tree overlay support.

Signed-off-by: Alan Tull <atull@kernel.org>
---
v2: split out from another patch
---
drivers/fpga/fpga-region.c | 129 +++++++++++++++++++++++++++------------------
1 file changed, 77 insertions(+), 52 deletions(-)

diff --git a/drivers/fpga/fpga-region.c b/drivers/fpga/fpga-region.c
index 1892126..3fd4674a 100644
--- a/drivers/fpga/fpga-region.c
+++ b/drivers/fpga/fpga-region.c
@@ -329,33 +329,22 @@ static int child_regions_with_firmware(struct device_node *overlay)
}

/**
- * fpga_region_notify_pre_apply - pre-apply overlay notification
- *
- * @region: FPGA region that the overlay was applied to
- * @nd: overlay notification data
- *
- * Called after when an overlay targeted to a FPGA Region is about to be
- * applied. Function will check the properties that will be added to the FPGA
- * region. If the checks pass, it will program the FPGA.
- *
- * The checks are:
- * The overlay must add either firmware-name or external-fpga-config property
- * to the FPGA Region.
+ * of_fpga_region_parse_ov - parse and check overlay applied to region
*
- * firmware-name : program the FPGA
- * external-fpga-config : FPGA is already programmed
- * encrypted-fpga-config : FPGA bitstream is encrypted
- *
- * The overlay can add other FPGA regions, but child FPGA regions cannot have a
- * firmware-name property since those regions don't exist yet.
+ * @region: FPGA region
+ * @overlay: overlay applied to the FPGA region
*
- * If the overlay that breaks the rules, notifier returns an error and the
- * overlay is rejected before it goes into the main tree.
+ * Given an overlay applied to a FPGA region, parse the FPGA image specific
+ * info in the overlay and do some checking.
*
- * Returns 0 for success or negative error code for failure.
+ * Returns:
+ * NULL if overlay doesn't direct us to program the FPGA.
+ * fpga_image_info struct if there is an image to program.
+ * error code for invalid overlay.
*/
-static int fpga_region_notify_pre_apply(struct fpga_region *region,
- struct of_overlay_notify_data *nd)
+static struct fpga_image_info *of_fpga_region_parse_ov(
+ struct fpga_region *region,
+ struct device_node *overlay)
{
struct device *dev = &region->dev;
struct fpga_image_info *info;
@@ -364,7 +353,7 @@ static int fpga_region_notify_pre_apply(struct fpga_region *region,

if (region->info) {
dev_err(dev, "Region already has overlay applied.\n");
- return -EINVAL;
+ return ERR_PTR(-EINVAL);
}

/*
@@ -372,68 +361,104 @@ static int fpga_region_notify_pre_apply(struct fpga_region *region,
* firmware-name property (would mean that an FPGA region that has
* not been added to the live tree yet is doing FPGA programming).
*/
- ret = child_regions_with_firmware(nd->overlay);
+ ret = child_regions_with_firmware(overlay);
if (ret)
- return ret;
+ return ERR_PTR(ret);

info = fpga_image_info_alloc(dev);
if (!info)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);

- info->overlay = nd->overlay;
+ info->overlay = overlay;

/* Read FPGA region properties from the overlay */
- if (of_property_read_bool(nd->overlay, "partial-fpga-config"))
+ if (of_property_read_bool(overlay, "partial-fpga-config"))
info->flags |= FPGA_MGR_PARTIAL_RECONFIG;

- if (of_property_read_bool(nd->overlay, "external-fpga-config"))
+ if (of_property_read_bool(overlay, "external-fpga-config"))
info->flags |= FPGA_MGR_EXTERNAL_CONFIG;

- if (of_property_read_bool(nd->overlay, "encrypted-fpga-config"))
+ if (of_property_read_bool(overlay, "encrypted-fpga-config"))
info->flags |= FPGA_MGR_ENCRYPTED_BITSTREAM;

- if (!of_property_read_string(nd->overlay, "firmware-name",
+ if (!of_property_read_string(overlay, "firmware-name",
&firmware_name)) {
info->firmware_name = devm_kstrdup(dev, firmware_name,
GFP_KERNEL);
if (!info->firmware_name)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);
}

- of_property_read_u32(nd->overlay, "region-unfreeze-timeout-us",
+ of_property_read_u32(overlay, "region-unfreeze-timeout-us",
&info->enable_timeout_us);

- of_property_read_u32(nd->overlay, "region-freeze-timeout-us",
+ of_property_read_u32(overlay, "region-freeze-timeout-us",
&info->disable_timeout_us);

- of_property_read_u32(nd->overlay, "config-complete-timeout-us",
+ of_property_read_u32(overlay, "config-complete-timeout-us",
&info->config_complete_timeout_us);

- /* If FPGA was externally programmed, don't specify firmware */
- if ((info->flags & FPGA_MGR_EXTERNAL_CONFIG) && info->firmware_name) {
- dev_err(dev, "error: specified firmware and external-fpga-config");
- fpga_image_info_free(dev, info);
- return -EINVAL;
+ /* If overlay is not programming the FPGA, don't need FPGA image info */
+ if (!info->firmware_name) {
+ ret = 0;
+ goto ret_no_info;
}

- /* FPGA is already configured externally. We're done. */
+ /*
+ * If overlay informs us FPGA was externally programmed, specifying
+ * firmware here would be ambiguous.
+ */
if (info->flags & FPGA_MGR_EXTERNAL_CONFIG) {
- fpga_image_info_free(&region->dev, info);
- return 0;
+ dev_err(dev, "error: specified firmware and external-fpga-config");
+ ret = -EINVAL;
+ goto ret_no_info;
}

- /* If we got this far, we should be programming the FPGA */
- if (!info->firmware_name) {
- dev_err(dev, "should specify firmware-name or external-fpga-config\n");
- fpga_image_info_free(dev, info);
+ return info;
+ret_no_info:
+ fpga_image_info_free(dev, info);
+ return ERR_PTR(ret);
+}
+
+/**
+ * fpga_region_notify_pre_apply - pre-apply overlay notification
+ *
+ * @region: FPGA region that the overlay was applied to
+ * @nd: overlay notification data
+ *
+ * Called when an overlay targeted to a FPGA Region is about to be applied.
+ * Parses the overlay for properties that influence how the FPGA will be
+ * programmed and does some checking. If the checks pass, programs the FPGA.
+ * If the checks fail, overlay is rejected and does not get added to the
+ * live tree.
+ *
+ * Returns 0 for success or negative error code for failure.
+ */
+static int fpga_region_notify_pre_apply(struct fpga_region *region,
+ struct of_overlay_notify_data *nd)
+{
+ struct device *dev = &region->dev;
+ struct fpga_image_info *info;
+ int ret;
+
+ if (region->info) {
+ dev_err(dev, "Region already has overlay applied.\n");
return -EINVAL;
}

- ret = fpga_region_program_fpga(region, info);
- if (ret)
- fpga_image_info_free(&region->dev, info);
+ info = of_fpga_region_parse_ov(region, nd->overlay);
+ if (IS_ERR(info))
+ return PTR_ERR(info);

- return ret;
+ if (info) {
+ ret = fpga_region_program_fpga(region, info);
+ if (ret) {
+ fpga_image_info_free(dev, info);
+ return ret;
+ }
+ }
+
+ return 0;
}

/**
--
2.7.4