[PATCHv2 3/3] fpga_mgr: Add streaming support through the new driver_data API

[yi1 . li]

From: Yi Li <yi1.li@xxxxxxxxxxxxxxx>

Since the FPGA image are getting bigger in size, this add an new API
fpga_mgr_firmware_stream in FPGA manager, which will stream FPGA image in
4KB trunks.

Signed-off-by: Yi Li <yi1.li@xxxxxxxxxxxxxxx>
---
 drivers/fpga/fpga-mgr.c       | 111 ++++++++++++++++++++++++++++++++++++++++++
 include/linux/fpga/fpga-mgr.h |   4 ++
 2 files changed, 115 insertions(+)

diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
index 188ffef..420ee38 100644
--- a/drivers/fpga/fpga-mgr.c
+++ b/drivers/fpga/fpga-mgr.c
@@ -27,6 +27,8 @@
 #include <linux/slab.h>
 #include <linux/scatterlist.h>
 #include <linux/highmem.h>
+#include <linux/sizes.h>
+#include <linux/driver_data.h>
 
 static DEFINE_IDA(fpga_mgr_ida);
 static struct class *fpga_mgr_class;
@@ -196,6 +198,115 @@ static int fpga_mgr_buf_load_mapped(struct fpga_manager *mgr,
 	return fpga_mgr_write_complete(mgr, info);
 }
 
+struct fpga_mgr_streaming_priv_params {
+	struct fpga_image_info *info;
+	struct fpga_manager *mgr;
+	loff_t offset;
+	loff_t fw_size;
+};
+
+static int fpga_mgr_streaming_fw_cb(void *context, const struct firmware *fw,
+				    int err)
+{
+	int ret = -EINVAL;
+	struct fpga_mgr_streaming_priv_params *params =
+		(struct fpga_mgr_streaming_priv_params *)context;
+	struct fpga_image_info *info = params->info;
+	struct fpga_manager *mgr = params->mgr;
+	struct device *dev = &mgr->dev;
+
+	params->fw_size = fw->size;
+	/*
+	 * init.
+	 */
+	if (params->offset == 0) {
+		ret = fpga_mgr_write_init_buf(mgr, info, fw->data, fw->size);
+		if (ret)
+			return ret;
+	}
+
+	/*
+	 * 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;
+		return ret;
+	}
+
+	if (fw->size < SZ_4K)
+		ret = fpga_mgr_write_complete(mgr, info);
+
+	return ret;
+}
+
+/**
+ * fpga_mgr_firmware_stream - streaming firmware and load to fpga
+ * @mgr:	fpga manager
+ * @info:	fpga image specific information
+ * @image_name:	name of image file on the firmware search path
+ *
+ * Streaming 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)
+{
+	int ret;
+	char *path = NULL;
+	void *buf;
+	size_t length = INT_MAX;
+	struct device *dev = &mgr->dev;
+	struct fpga_mgr_streaming_priv_params params = {
+		.info = info,
+		.mgr = mgr,
+		.fw_size = 0,
+		.offset = 0,
+	};
+
+	const struct driver_data_req_params req_params = {
+		DRIVER_DATA_DEFAULT_SYNC(fpga_mgr_streaming_fw_cb, &params),
+		.reqs = DRIVER_DATA_REQ_NO_CACHE | DRIVER_DATA_REQ_STREAMING,
+		.alloc_buf_size = SZ_4K,
+		.alloc_buf = &buf,
+		.img_offset = &params.offset,
+		.path = &path,
+	};
+
+	buf = kmalloc(SZ_4K, GFP_KERNEL);
+	if (!buf) {
+		dev_err(dev, "%s: kmalloc buf failed\n", __func__);
+		return -ENOMEM;
+	}
+
+	mgr->state = FPGA_MGR_STATE_FIRMWARE_REQ;
+	while (length > 0) {
+		ret = driver_data_request_sync(image_name, &req_params, dev);
+		if (ret) {
+			dev_err(dev, "Error reading firmware %d\n", ret);
+			mgr->state = FPGA_MGR_STATE_FIRMWARE_REQ_ERR;
+			return ret;
+		}
+
+		length -= params.fw_size;
+		params.offset += params.fw_size;
+		if (params.fw_size < SZ_4K)
+			break;
+	}
+
+	kfree(buf);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(fpga_mgr_firmware_stream);
+
 /**
  * fpga_mgr_buf_load - load fpga from image in buffer
  * @mgr:	fpga manager
diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
index b4ac24c..083e091 100644
--- a/include/linux/fpga/fpga-mgr.h
+++ b/include/linux/fpga/fpga-mgr.h
@@ -143,6 +143,10 @@ 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);
+
 struct fpga_manager *of_fpga_mgr_get(struct device_node *node);
 
 struct fpga_manager *fpga_mgr_get(struct device *dev);
-- 
2.7.4