From 593371de824fe9150a73b3b6299c0a3f66ed43cd Mon Sep 17 00:00:00 2001
From: ben <ben@766a2236-cff9-0310-b0c0-a81a5f92509a>
Date: Sun, 1 Jul 2007 09:55:49 +0000
Subject: [PATCH] add basic write/read commands for file cmd and stat

git-svn-id: svn+ssh://en.codiert.org/home/staff/ben/dev/misc.svn/projects/fpgafs@343 766a2236-cff9-0310-b0c0-a81a5f92509a
---
 files.c  | 92 ++++++++++++++++++++++++++++++++------------------------
 fpgafs.h |  2 ++
 2 files changed, 54 insertions(+), 40 deletions(-)

diff --git a/files.c b/files.c
index c36d35d..beaa651 100644
--- a/files.c
+++ b/files.c
@@ -9,66 +9,78 @@
 #include <linux/pagemap.h>
 #include "fpgafs.h"
 
-/* generic open function for all pipe-like files */
-static int fpgafs_pipe_open(struct inode *inode, struct file *file)
-{
-	struct fpgafs_inode_info *i = FPGAFS_I(inode);
-	file->private_data = i->i_ctx;
+static unsigned int stat;
 
-  return nonseekable_open(inode, file);
+static int do_cmd(u32 cmd, u32 data)
+{
+	switch(cmd) {
+		case BLA:
+			stat = data;
+			break;
+		default:
+			return -EFAULT;
+	}
+	return 0;
+}
+
+/* generic open function for all pipe-like files */
+static int fpgafs_open(struct inode *inode, struct file *file)
+{
+	//struct fpgafs_inode_info *i = FPGAFS_I(inode);
+	//file->private_data = i->i_ctx;
+
+  return 0; // nonseekable_open(inode, file);
 }
 
 static ssize_t fpgafs_stat_read(struct file *file, char __user *buf,
-	                              size_t len, loff_t *pos)
-{
+                                size_t len, loff_t *pos)
+ {
 	//struct fpga_context *ctx = file->private_data;
+	u32 data;
+	data=stat;
+
+	if (copy_to_user(buf, &data, sizeof(data)))
+		return -EFAULT;
+
+	return 4;
+}
+
+static const struct file_operations fpgafs_stat_fops = {
+	.open = fpgafs_open,
+	.read = fpgafs_stat_read,
+};
+
+static ssize_t fpgafs_cmd_write(struct file *file, const char __user *buf,
+                                size_t len, loff_t *pos)
+{
 	u32 data, __user *udata;
-	ssize_t count;
 
 	if (len < 4)
 		return -EINVAL;
 
-	if (!access_ok(VERIFY_WRITE, buf, len))
-	return -EFAULT;
-
 	udata = (void __user *)buf;
+	if (!access_ok(VERIFY_READ, buf, len))
+		return -EFAULT;
 
-	for (count = 0; (count + 4) <= len; count += 4, udata++) {
-		int ret;
+	if (__get_user(data, udata))
+		return -EFAULT;
 
-		/* operation to read the status ... */
-		data=0x42;
-		ret = 0;
-		if (ret == 0)
-			break;
-
-		ret = __put_user(data, udata);
-
-		if (ret) {
-			if (!count)
-				count = -EFAULT;
-				break;
-		}
-	}
-
-	if (!count)
-		count = -EAGAIN;
-
-	return count;
+	do_cmd(BLA,data);
+	return 4;
 }
 
-static const struct file_operations fpgafs_stat_fops = {
-	.open = fpgafs_pipe_open,
-	.read = fpgafs_stat_read,
+static const struct file_operations fpgafs_cmd_fops = {
+	.open  = fpgafs_open,
+	.write = fpgafs_cmd_write,
 };
 
 struct tree_descr fpgafs_dir_contents[] = {
 #if 0
-	{ "cmd",  &fpgafs_cmd_fops,  0222, },
-	{ "din",  &spufs_mbox_fops, 0222, },
-	{ "dout", &spufs_ibox_fops, 0444, },
-	{ "load", &spufs_wbox_fops, 0666, },
+	{ "din",  &fpgafs_din_fops, 0222, },
+	{ "dout", &fpgafs_dout_fops, 0444, },
+	{ "load", &fpgafs_load_fops, 0666, },
 #endif
+	{ "cmd",  &fpgafs_cmd_fops,  0222, },
 	{ "stat", &fpgafs_stat_fops, 0444, },
 	{},
 };
diff --git a/fpgafs.h b/fpgafs.h
index ee15ad2..20d1480 100644
--- a/fpgafs.h
+++ b/fpgafs.h
@@ -26,4 +26,6 @@ extern struct tree_descr fpgafs_dir_contents[];
 #define FPGAFS_I(inode) \
 		container_of(inode, struct fpgafs_inode_info, vfs_inode)
 
+#define BLA 0
+
 #endif /* FPGAFS_H */