[RFC 2/2] fpga manager: Add fpga_mgr_firmware_stream API

[yi1 . li]

From: Yi Li <yi1.li@xxxxxxxxxxxxxxx>

Add fpga_mgr_firmware_stream API, which can load and program firmware

in trucks to FPGA instead of the whole file.

Signed-off-by: Yi Li <yi1.li@xxxxxxxxxxxxxxx>
---
 drivers/fpga/fpga-mgr.c       | 77 +++++++++++++++++++++++++++++++++++++++++++
 include/linux/fpga/fpga-mgr.h |  4 +++
 2 files changed, 81 insertions(+)

diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
index 3206a53..bb55b80 100644
--- a/drivers/fpga/fpga-mgr.c
+++ b/drivers/fpga/fpga-mgr.c
@@ -27,10 +27,15 @@
 #include <linux/slab.h>
 #include <linux/scatterlist.h>
 #include <linux/highmem.h>
+#include <linux/sizes.h>
 
 static DEFINE_IDA(fpga_mgr_ida);
 static struct class *fpga_mgr_class;
 
+static int streamsize = SZ_4K;
+module_param(streamsize, int, 0664);
+MODULE_PARM_DESC(streamsize, "buffer size for firmware streaming");
+
 /*
  * Call the low level driver's write_init function.  This will do the
  * device-specific things to get the FPGA into the state where it is ready to
@@ -309,6 +314,78 @@ int fpga_mgr_firmware_load(struct fpga_manager *mgr,
 }
 EXPORT_SYMBOL_GPL(fpga_mgr_firmware_load);
 
+/**
+ * fpga_mgr_firmware_load - request firmware and load to fpga
+ * @mgr:	fpga manager
+ * @info:	fpga image specific information
+ * @image_name:	name of image file on the firmware search path
+ *
+ * Request an FPGA image using the firmware class, then write out to the FPGA.
+ * Update the state before each step to provide info on what step failed if
+ * there is a failure.  This code assumes the caller got the mgr pointer
+ * from of_fpga_mgr_get() or fpga_mgr_get() and checked that it is not an error
+ * code.
+ *
+ * Return: 0 on success, negative error code otherwise.
+ */
+int fpga_mgr_firmware_stream(struct fpga_manager *mgr,
+			   struct fpga_image_info *info,
+			   const char *image_name)
+{
+	struct device *dev = &mgr->dev;
+	const struct firmware *fw = NULL;
+	int ret;
+	size_t size = INT_MAX, offset = 0;
+	bool start_flag = 1;
+
+	dev_info(dev, "writing %s to %s with buffer size %d\n",
+			image_name, mgr->name, streamsize);
+
+	mgr->state = FPGA_MGR_STATE_FIRMWARE_REQ;
+
+	while (size > 0) {
+		ret = stream_firmware(&fw, image_name, dev, offset, streamsize);
+		if (ret) {
+			dev_err(dev, "Error reading firmware %d\n", ret);
+			mgr->state = FPGA_MGR_STATE_FIRMWARE_REQ_ERR;
+			break;
+		}
+
+		/*
+		 * init.
+		 */
+		if (start_flag) {
+			ret = fpga_mgr_write_init_buf(mgr, info, fw->data,
+						      fw->size);
+			start_flag = 0;
+			if (ret)
+				break;
+		}
+
+		/*
+		 * Write the FPGA image to the FPGA.
+		 */
+		mgr->state = FPGA_MGR_STATE_WRITE;
+		ret = mgr->mops->write(mgr, fw->data, fw->size);
+		if (ret) {
+			dev_err(dev, "Error while writing image data to FPGA\n");
+			mgr->state = FPGA_MGR_STATE_WRITE_ERR;
+			break;
+		}
+
+		offset += fw->size;
+		size -= fw->size;
+		if (fw->size < streamsize)
+			break;
+	}
+
+	ret = fpga_mgr_write_complete(mgr, info);
+
+	release_firmware(fw);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(fpga_mgr_firmware_stream);
+
 int fpga_mgr_load(struct fpga_manager *mgr, struct fpga_image_info *info)
 {
 	if (info->firmware_name)
diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
index 0f5072c..a25362e 100644
--- a/include/linux/fpga/fpga-mgr.h
+++ b/include/linux/fpga/fpga-mgr.h
@@ -151,6 +151,10 @@ int fpga_mgr_firmware_load(struct fpga_manager *mgr,
 			   struct fpga_image_info *info,
 			   const char *image_name);
 
+int fpga_mgr_firmware_stream(struct fpga_manager *mgr,
+			   struct fpga_image_info *info,
+			   const char *image_name);
+
 int fpga_mgr_load(struct fpga_manager *mgr, struct fpga_image_info *info);
 
 int fpga_mgr_lock(struct fpga_manager *mgr);
-- 
2.7.4