diff options
Diffstat (limited to 'drivers/usb/serial/sam-ba.c')
| -rw-r--r-- | drivers/usb/serial/sam-ba.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/drivers/usb/serial/sam-ba.c b/drivers/usb/serial/sam-ba.c new file mode 100644 index 000000000000..e3bba64afc57 --- /dev/null +++ b/drivers/usb/serial/sam-ba.c @@ -0,0 +1,206 @@ +/* + * 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"); |