/* * Atmel SAM Boot Assistant (SAM-BA) driver * * Copyright (C) 2010 Johan Hovold <jhovold@gmail.com> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License version * 2 as published by the Free Software Foundation. */ #include <linux/kernel.h> #include <linux/tty.h> #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/usb.h> #include <linux/usb/serial.h> #define DRIVER_VERSION "v1.0" #define DRIVER_AUTHOR "Johan Hovold <jhovold@gmail.com>" #define DRIVER_DESC "Atmel SAM Boot Assistant (SAM-BA) driver" #define SAMBA_VENDOR_ID 0x3eb #define SAMBA_PRODUCT_ID 0x6124 static int debug; static const struct usb_device_id id_table[] = { /* * NOTE: Only match the CDC Data interface. */ { USB_DEVICE_AND_INTERFACE_INFO(SAMBA_VENDOR_ID, SAMBA_PRODUCT_ID, USB_CLASS_CDC_DATA, 0, 0) }, { } }; MODULE_DEVICE_TABLE(usb, id_table); static struct usb_driver samba_driver = { .name = "sam-ba", .probe = usb_serial_probe, .disconnect = usb_serial_disconnect, .id_table = id_table, .no_dynamic_id = 1, }; /* * NOTE: The SAM-BA firmware cannot handle merged write requests so we cannot * use the generic write implementation (which uses the port write fifo). */ static int samba_write(struct tty_struct *tty, struct usb_serial_port *port, const unsigned char *buf, int count) { struct urb *urb; unsigned long flags; int result; int i; if (!count) return 0; count = min_t(int, count, port->bulk_out_size); spin_lock_irqsave(&port->lock, flags); if (!port->write_urbs_free) { spin_unlock_irqrestore(&port->lock, flags); return 0; } i = find_first_bit(&port->write_urbs_free, ARRAY_SIZE(port->write_urbs)); __clear_bit(i, &port->write_urbs_free); port->tx_bytes += count; spin_unlock_irqrestore(&port->lock, flags); urb = port->write_urbs[i]; memcpy(urb->transfer_buffer, buf, count); urb->transfer_buffer_length = count; usb_serial_debug_data(debug, &port->dev, __func__, count, urb->transfer_buffer); result = usb_submit_urb(urb, GFP_ATOMIC); if (result) { dev_err(&port->dev, "%s - error submitting urb: %d\n", __func__, result); spin_lock_irqsave(&port->lock, flags); __set_bit(i, &port->write_urbs_free); port->tx_bytes -= count; spin_unlock_irqrestore(&port->lock, flags); return result; } return count; } static int samba_write_room(struct tty_struct *tty) { struct usb_serial_port *port = tty->driver_data; unsigned long flags; unsigned long free; int count; int room; spin_lock_irqsave(&port->lock, flags); free = port->write_urbs_free; spin_unlock_irqrestore(&port->lock, flags); count = hweight_long(free); room = count * port->bulk_out_size; dbg("%s - returns %d", __func__, room); return room; } static int samba_chars_in_buffer(struct tty_struct *tty) { struct usb_serial_port *port = tty->driver_data; unsigned long flags; int chars; spin_lock_irqsave(&port->lock, flags); chars = port->tx_bytes; spin_unlock_irqrestore(&port->lock, flags); dbg("%s - returns %d", __func__, chars); return chars; } static void samba_write_bulk_callback(struct urb *urb) { struct usb_serial_port *port = urb->context; unsigned long flags; int i; dbg("%s - port %d", __func__, port->number); for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i) { if (port->write_urbs[i] == urb) break; } spin_lock_irqsave(&port->lock, flags); __set_bit(i, &port->write_urbs_free); port->tx_bytes -= urb->transfer_buffer_length; spin_unlock_irqrestore(&port->lock, flags); if (urb->status) dbg("%s - non-zero urb status: %d", __func__, urb->status); usb_serial_port_softint(port); } static struct usb_serial_driver samba_device = { .driver = { .owner = THIS_MODULE, .name = "sam-ba", }, .usb_driver = &samba_driver, .id_table = id_table, .num_ports = 1, .bulk_in_size = 512, .bulk_out_size = 2048, .write = samba_write, .write_room = samba_write_room, .chars_in_buffer = samba_chars_in_buffer, .write_bulk_callback = samba_write_bulk_callback, .throttle = usb_serial_generic_throttle, .unthrottle = usb_serial_generic_unthrottle, }; static int __init samba_init(void) { int retval; retval = usb_serial_register(&samba_device); if (retval) return retval; retval = usb_register(&samba_driver); if (retval) { usb_serial_deregister(&samba_device); return retval; } printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ": " DRIVER_DESC "\n"); return 0; } static void __exit samba_exit(void) { usb_deregister(&samba_driver); usb_serial_deregister(&samba_device); } module_init(samba_init); module_exit(samba_exit); MODULE_AUTHOR(DRIVER_AUTHOR); MODULE_DESCRIPTION(DRIVER_DESC); MODULE_VERSION(DRIVER_VERSION); MODULE_LICENSE("GPL"); module_param(debug, bool, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(debug, "Enable verbose debugging messages");