Messages in this thread |  | | From | "eshwar" <> | Subject | Write USB Device Driver entry not called | Date | Thu, 21 Oct 2004 17:14:48 +0530 |
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I am writing usb Device Driver for vendor specific Device for the kernel 2.6.8 ... When i have loaded my skelton usb driver ioctl,read,probe,disconnect,release entry points are working fine but when i issue write() returns as bad file descriptor.... even though i have open the device file with S_IWUSR
The error message is comming vfs_wirte() function
if (!(file->f_mode & FMODE_WRITE)) return -EBADF;
It seems to be f_mode is not set with FMODE_WRITE
Can any one help me to fix this problem.... Thanks in Advance
Regards Eshwar
The skelton driver is as follows and application code follows the driver code...
Driver.c
#include <linux/module.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/usb.h> #include <asm/uaccess.h>
/* Function prototypes */ static int otg_cli_open ( struct inode *inode, struct file *file); /* Function prototypes */ static int otg_cli_open ( struct inode *inode, struct file *file); static void otg_cli_disconnect( struct usb_interface *intf); static int otg_cli_release ( struct inode *inode, struct file *file); static ssize_t otg_cli_read (struct file *file, char *buffer, size_t count, loff_t *ppos); static ssize_t otg_cli_write (struct file *file, const char *buffer, size_t count, loff_t *ppos); static int otg_cli_probe( struct usb_interface *intf, const struct usb_device_id *id);
static struct usb_device_id otg_device_id[] = { { USB_INTERFACE_INFO(USB_CLASS_VENDOR_SPEC, 0x00, 0xff) }, {}, };
struct usb_driver otg_cli_driver = { .owner = THIS_MODULE, .name = "xyz", .probe = otg_cli_probe, .disconnect = otg_cli_disconnect, .id_table = otg_device_id, };
static struct file_operations otg_cli_fops = { .owner = THIS_MODULE, .write = otg_cli_write, .open = otg_cli_open, .read = otg_cli_read, .release = otg_cli_release, };
static struct usb_class_driver otg_cli_class = { .name = "xyz", .fops = &otg_cli_fops, };
static struct usb_class_driver otg_cli_class = { .name = "moschip-otg", .fops = &otg_cli_fops, .mode = S_IRWXU | S_IRWXG | S_IRWXO | S_IFCHR, .minor_base = 250, };
static int otg_cli_ioctl ( struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) {
printk("Eshwar: otg_cli_ioctl"); return 0; }
static ssize_t otg_cli_read (struct file *file, char *buffer, size_t count, loff_t *ppos) { printk("Eshwar: otg_cli_read"); return 0; }
static ssize_t otg_cli_write (struct file *file, const char *buffer, size_t count,loff_t *ppos) { printk("Eshwar: otg_cli_write"); return 0; }
static int otg_cli_open ( struct inode *inode, struct file *file) { printk("Eshwar: otg_cli_open"); return 0; }
static int otg_cli_release ( struct inode *inode, struct file *file) { printk("Eshwar: otg_cli_release"); return 0; }
static int otg_cli_probe( struct usb_interface *intf, const struct usb_device_id *id) {
printk("Eshwar: otg_cli_probe\n"); return 0; }
static void otg_cli_disconnect( struct usb_interface *intf) { printk("Eshwar: otg_cli_disconnect\n"); usb_deregister_dev (intf, &otg_cli_class); }
static int __init otg_cli_init(void) { printk ("Eshwar: otg_cli_init\n"); /* register this driver with the USB subsystem */ usb_register(&otg_cli_driver); return 0; }
/* OTG cleanup module */ static void __exit otg_cli_exit(void) { usb_deregister(&otg_cli_driver); }
module_init (otg_cli_init); module_exit (otg_cli_exit);
app.c
int main(int argc, char *argv[]) { int devfd; char send[512];
memset(send,'a',512);
devfd = open("/dev/usb/dabusb10",O_APPEND | S_IRUSR| S_IWUSR ); if ( write(devfd,send,512) < 0) { printf ("write Failed\n"); return -1; }
return 0;
}
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