add basic low level driver managment.

git-svn-id: svn+ssh://en.codiert.org/home/staff/ben/dev/misc.svn/projects/fpgafs@345 766a2236-cff9-0310-b0c0-a81a5f92509a

Makefile

@@ -3,7 +3,11 @@ KERNEL_BUILDROOT ?= /lib/modules/$(KERNEL_RELEASE)/build
 BUILDROOT = $(shell pwd)
 
 obj-m       := fpgafs.o
-fpgafs-objs := files.o inode.o
+fpgafs-objs := files.o inode.o llmgmt.o
+
+# low level driver
+obj-m       += fpgafs_lldrv_dbg.o
+obj-m       += fpgafs_lldrv_cham.o
 
 all :
 	$(MAKE) -C $(KERNEL_BUILDROOT) SUBDIRS=$(BUILDROOT) modules

files.c

@@ -42,6 +42,7 @@ static ssize_t fpgafs_stat_read(struct file *file, char __user *buf,
 	if (copy_to_user(buf, &data, sizeof(data)))
 		return -EFAULT;
 
+	fpgafs_recv_data(NULL, 1);
 	return 4;
 }
 
@@ -66,6 +67,7 @@ static ssize_t fpgafs_cmd_write(struct file *file, const char __user *buf,
 		return -EFAULT;
 
 	do_cmd(BLA,data);
+	fpgafs_send_data(NULL, 1);
 	return 4;
 }
 

fpgafs.h

@@ -1,3 +1,6 @@
+/*********************************************
+ * Benjamin Krill <ben@codiert.org>
+ *********************************************/
 #ifndef FPGAFS_H
 #define FPGAFS_H
 
@@ -26,6 +29,25 @@ extern struct tree_descr fpgafs_dir_contents[];
 #define FPGAFS_I(inode) \
 		container_of(inode, struct fpgafs_inode_info, vfs_inode)
 
+
+/* command definitions */
 #define BLA 0
 
+/* low level driver */
+struct fpgafs_lldrv {
+	char name[5];
+
+	int (*init) (void);
+	int (*exit) (void);
+
+	int (*send) (unsigned char *buf, int len);
+	int (*recv) (unsigned char *buf, int len);
+};
+
+int fpgafs_register_lldrv(struct fpgafs_lldrv *drv);
+int fpgafs_unregister_lldrv(struct fpgafs_lldrv *drv);
+
+int fpgafs_send_data(char *buf, int len);
+int fpgafs_recv_data(char *buf, int len);
+
 #endif /* FPGAFS_H */

fpgafs_lldrv_cham.c

@@ -0,0 +1,44 @@
+/*********************************************
+ * Benjamin Krill <ben@codiert.org>
+ *********************************************/
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include "fpgafs.h"
+
+static int fpgafs_send_data_cham(unsigned char *buf, int len)
+{
+	printk("fpgafs: send data CHAM\n");
+	return 0;
+}
+
+static int fpgafs_recv_data_cham(unsigned char *buf, int len)
+{
+	printk("fpgafs: receive data CHAM\n");
+	return 4;
+}
+
+static struct fpgafs_lldrv fpgafs_lldrv_cham = {
+	.name = "cham",
+	.init = NULL,
+	.exit = NULL,
+	.send = &fpgafs_send_data_cham,
+	.recv = &fpgafs_recv_data_cham
+};
+
+/* init exit functions ... */
+int __init fpgafs_lldrv_cham_init(void)
+{
+	return fpgafs_register_lldrv(&fpgafs_lldrv_cham);
+}
+
+void __exit fpgafs_lldrv_cham_exit(void)
+{
+	fpgafs_unregister_lldrv(&fpgafs_lldrv_cham);
+}
+
+module_init(fpgafs_lldrv_cham_init);
+module_exit(fpgafs_lldrv_cham_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Benjamin Krill <ben@codiert.org>");

fpgafs_lldrv_dbg.c

@@ -0,0 +1,44 @@
+/*********************************************
+ * Benjamin Krill <ben@codiert.org>
+ *********************************************/
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include "fpgafs.h"
+
+static int fpgafs_send_data_dbg(unsigned char *buf, int len)
+{
+	printk("fpgafs: send data CHAM\n");
+	return 0;
+}
+
+static int fpgafs_recv_data_dbg(unsigned char *buf, int len)
+{
+	printk("fpgafs: receive data CHAM\n");
+	return 4;
+}
+
+static struct fpgafs_lldrv fpgafs_lldrv_dbg = {
+	.name = "dbg",
+	.init = NULL,
+	.exit = NULL,
+	.send = &fpgafs_send_data_dbg,
+	.recv = &fpgafs_recv_data_dbg
+};
+
+/* init exit functions ... */
+int __init fpgafs_lldrv_dbg_init(void)
+{
+	return fpgafs_register_lldrv(&fpgafs_lldrv_dbg);
+}
+
+void __exit fpgafs_lldrv_dbg_exit(void)
+{
+	fpgafs_unregister_lldrv(&fpgafs_lldrv_dbg);
+}
+
+module_init(fpgafs_lldrv_dbg_init);
+module_exit(fpgafs_lldrv_dbg_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Benjamin Krill <ben@codiert.org>");

llmgmt.c

@@ -0,0 +1,86 @@
+/*********************************************
+ * Benjamin Krill <ben@codiert.org>
+ *********************************************/
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include "fpgafs.h"
+
+#define FPGAFS_MAX_LLDRV 3
+
+static struct fpgafs_lldrv *lldrv[FPGAFS_MAX_LLDRV];
+static struct fpgafs_lldrv *lldrv_cur;
+static int lldrv_count = 0x0;
+static DEFINE_SPINLOCK(fpgafs_lldrv_lock);
+
+int fpgafs_send_data(char *buf, int len)
+{
+	return (lldrv_cur)?lldrv_cur->send(buf, len) : -EBUSY;
+}
+EXPORT_SYMBOL_GPL(fpgafs_send_data);
+
+int fpgafs_recv_data(char *buf, int len)
+{
+	return (lldrv_cur) ? lldrv_cur->recv(buf, len) : -EBUSY;
+}
+EXPORT_SYMBOL_GPL(fpgafs_recv_data);
+
+int fpgafs_register_lldrv(struct fpgafs_lldrv *drv)
+{
+	unsigned long flags;
+	int i;
+
+	spin_lock_irqsave(&fpgafs_lldrv_lock, flags);
+	if (lldrv_count == FPGAFS_MAX_LLDRV)
+		return -EBUSY;
+
+	/* find free space */
+	for(i=0; i < FPGAFS_MAX_LLDRV; i++)
+		if (lldrv[lldrv_count] == NULL) {
+			lldrv[lldrv_count] = drv;
+			break;
+		}
+
+	if (lldrv[lldrv_count]->init)
+		lldrv[lldrv_count]->init();
+
+	lldrv_cur = lldrv[lldrv_count];
+
+	lldrv_count++;
+
+	spin_unlock_irqrestore(&fpgafs_lldrv_lock, flags);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(fpgafs_register_lldrv);
+
+int fpgafs_unregister_lldrv(struct fpgafs_lldrv *drv)
+{
+	unsigned long flags;
+	int i,k;
+
+	spin_lock_irqsave(&fpgafs_lldrv_lock, flags);
+
+	if (lldrv[lldrv_count]->exit)
+		lldrv[lldrv_count]->exit();
+
+	for(i=0; i < FPGAFS_MAX_LLDRV; i++) {
+		if (lldrv[i] == drv) {
+			lldrv[i] = NULL;
+			/* if current, search another low level driver */
+			if (lldrv_cur == drv) {
+				for(k=0; k < FPGAFS_MAX_LLDRV; k++)
+					if (lldrv[k]) {
+						lldrv_cur = lldrv[k];
+						break;
+					}
+			}
+			break;
+		}
+	}
+
+	lldrv_count--;
+
+	spin_unlock_irqrestore(&fpgafs_lldrv_lock, flags);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(fpgafs_unregister_lldrv);