linux/drivers/usb/serial/ir-usb.c
Ilpo Järvinen f6d47fe592 usb: serial: Make ->set_termios() old ktermios const
There should be no reason to adjust old ktermios which is going to get
discarded anyway.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220816115739.10928-8-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-30 14:22:35 +02:00

489 lines
12 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* USB IR Dongle driver
*
* Copyright (C) 2001-2002 Greg Kroah-Hartman (greg@kroah.com)
* Copyright (C) 2002 Gary Brubaker (xavyer@ix.netcom.com)
* Copyright (C) 2010 Johan Hovold (jhovold@gmail.com)
*
* This driver allows a USB IrDA device to be used as a "dumb" serial device.
* This can be useful if you do not have access to a full IrDA stack on the
* other side of the connection. If you do have an IrDA stack on both devices,
* please use the usb-irda driver, as it contains the proper error checking and
* other goodness of a full IrDA stack.
*
* Portions of this driver were taken from drivers/net/irda/irda-usb.c, which
* was written by Roman Weissgaerber <weissg@vienna.at>, Dag Brattli
* <dag@brattli.net>, and Jean Tourrilhes <jt@hpl.hp.com>
*
* See Documentation/usb/usb-serial.rst for more information on using this
* driver
*/
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <linux/usb/irda.h>
#define DRIVER_AUTHOR "Greg Kroah-Hartman <greg@kroah.com>, Johan Hovold <jhovold@gmail.com>"
#define DRIVER_DESC "USB IR Dongle driver"
/* if overridden by the user, then use their value for the size of the read and
* write urbs */
static int buffer_size;
/* if overridden by the user, then use the specified number of XBOFs */
static int xbof = -1;
static int ir_startup (struct usb_serial *serial);
static int ir_write(struct tty_struct *tty, struct usb_serial_port *port,
const unsigned char *buf, int count);
static unsigned int ir_write_room(struct tty_struct *tty);
static void ir_write_bulk_callback(struct urb *urb);
static void ir_process_read_urb(struct urb *urb);
static void ir_set_termios(struct tty_struct *tty,
struct usb_serial_port *port,
const struct ktermios *old_termios);
/* Not that this lot means you can only have one per system */
static u8 ir_baud;
static u8 ir_xbof;
static u8 ir_add_bof;
static const struct usb_device_id ir_id_table[] = {
{ USB_DEVICE(0x050f, 0x0180) }, /* KC Technology, KC-180 */
{ USB_DEVICE(0x08e9, 0x0100) }, /* XTNDAccess */
{ USB_DEVICE(0x09c4, 0x0011) }, /* ACTiSys ACT-IR2000U */
{ USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, USB_SUBCLASS_IRDA, 0) },
{ } /* Terminating entry */
};
MODULE_DEVICE_TABLE(usb, ir_id_table);
static struct usb_serial_driver ir_device = {
.driver = {
.owner = THIS_MODULE,
.name = "ir-usb",
},
.description = "IR Dongle",
.id_table = ir_id_table,
.num_ports = 1,
.num_bulk_in = 1,
.num_bulk_out = 1,
.set_termios = ir_set_termios,
.attach = ir_startup,
.write = ir_write,
.write_room = ir_write_room,
.write_bulk_callback = ir_write_bulk_callback,
.process_read_urb = ir_process_read_urb,
};
static struct usb_serial_driver * const serial_drivers[] = {
&ir_device, NULL
};
static inline void irda_usb_dump_class_desc(struct usb_serial *serial,
struct usb_irda_cs_descriptor *desc)
{
struct device *dev = &serial->dev->dev;
dev_dbg(dev, "bLength=%x\n", desc->bLength);
dev_dbg(dev, "bDescriptorType=%x\n", desc->bDescriptorType);
dev_dbg(dev, "bcdSpecRevision=%x\n", __le16_to_cpu(desc->bcdSpecRevision));
dev_dbg(dev, "bmDataSize=%x\n", desc->bmDataSize);
dev_dbg(dev, "bmWindowSize=%x\n", desc->bmWindowSize);
dev_dbg(dev, "bmMinTurnaroundTime=%d\n", desc->bmMinTurnaroundTime);
dev_dbg(dev, "wBaudRate=%x\n", __le16_to_cpu(desc->wBaudRate));
dev_dbg(dev, "bmAdditionalBOFs=%x\n", desc->bmAdditionalBOFs);
dev_dbg(dev, "bIrdaRateSniff=%x\n", desc->bIrdaRateSniff);
dev_dbg(dev, "bMaxUnicastList=%x\n", desc->bMaxUnicastList);
}
/*------------------------------------------------------------------*/
/*
* Function irda_usb_find_class_desc(dev, ifnum)
*
* Returns instance of IrDA class descriptor, or NULL if not found
*
* The class descriptor is some extra info that IrDA USB devices will
* offer to us, describing their IrDA characteristics. We will use that in
* irda_usb_init_qos()
*
* Based on the same function in drivers/net/irda/irda-usb.c
*/
static struct usb_irda_cs_descriptor *
irda_usb_find_class_desc(struct usb_serial *serial, unsigned int ifnum)
{
struct usb_device *dev = serial->dev;
struct usb_irda_cs_descriptor *desc;
int ret;
desc = kzalloc(sizeof(*desc), GFP_KERNEL);
if (!desc)
return NULL;
ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
USB_REQ_CS_IRDA_GET_CLASS_DESC,
USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
0, ifnum, desc, sizeof(*desc), 1000);
dev_dbg(&serial->dev->dev, "%s - ret=%d\n", __func__, ret);
if (ret < (int)sizeof(*desc)) {
dev_dbg(&serial->dev->dev,
"%s - class descriptor read %s (%d)\n", __func__,
(ret < 0) ? "failed" : "too short", ret);
goto error;
}
if (desc->bDescriptorType != USB_DT_CS_IRDA) {
dev_dbg(&serial->dev->dev, "%s - bad class descriptor type\n",
__func__);
goto error;
}
irda_usb_dump_class_desc(serial, desc);
return desc;
error:
kfree(desc);
return NULL;
}
static u8 ir_xbof_change(u8 xbof)
{
u8 result;
/* reference irda-usb.c */
switch (xbof) {
case 48:
result = 0x10;
break;
case 28:
case 24:
result = 0x20;
break;
default:
case 12:
result = 0x30;
break;
case 5:
case 6:
result = 0x40;
break;
case 3:
result = 0x50;
break;
case 2:
result = 0x60;
break;
case 1:
result = 0x70;
break;
case 0:
result = 0x80;
break;
}
return(result);
}
static int ir_startup(struct usb_serial *serial)
{
struct usb_irda_cs_descriptor *irda_desc;
int rates;
irda_desc = irda_usb_find_class_desc(serial, 0);
if (!irda_desc) {
dev_err(&serial->dev->dev,
"IRDA class descriptor not found, device not bound\n");
return -ENODEV;
}
rates = le16_to_cpu(irda_desc->wBaudRate);
dev_dbg(&serial->dev->dev,
"%s - Baud rates supported:%s%s%s%s%s%s%s%s%s\n",
__func__,
(rates & USB_IRDA_BR_2400) ? " 2400" : "",
(rates & USB_IRDA_BR_9600) ? " 9600" : "",
(rates & USB_IRDA_BR_19200) ? " 19200" : "",
(rates & USB_IRDA_BR_38400) ? " 38400" : "",
(rates & USB_IRDA_BR_57600) ? " 57600" : "",
(rates & USB_IRDA_BR_115200) ? " 115200" : "",
(rates & USB_IRDA_BR_576000) ? " 576000" : "",
(rates & USB_IRDA_BR_1152000) ? " 1152000" : "",
(rates & USB_IRDA_BR_4000000) ? " 4000000" : "");
switch (irda_desc->bmAdditionalBOFs) {
case USB_IRDA_AB_48:
ir_add_bof = 48;
break;
case USB_IRDA_AB_24:
ir_add_bof = 24;
break;
case USB_IRDA_AB_12:
ir_add_bof = 12;
break;
case USB_IRDA_AB_6:
ir_add_bof = 6;
break;
case USB_IRDA_AB_3:
ir_add_bof = 3;
break;
case USB_IRDA_AB_2:
ir_add_bof = 2;
break;
case USB_IRDA_AB_1:
ir_add_bof = 1;
break;
case USB_IRDA_AB_0:
ir_add_bof = 0;
break;
default:
break;
}
kfree(irda_desc);
return 0;
}
static int ir_write(struct tty_struct *tty, struct usb_serial_port *port,
const unsigned char *buf, int count)
{
struct urb *urb = NULL;
unsigned long flags;
int ret;
if (port->bulk_out_size == 0)
return -EINVAL;
if (count == 0)
return 0;
count = min(count, port->bulk_out_size - 1);
spin_lock_irqsave(&port->lock, flags);
if (__test_and_clear_bit(0, &port->write_urbs_free)) {
urb = port->write_urbs[0];
port->tx_bytes += count;
}
spin_unlock_irqrestore(&port->lock, flags);
if (!urb)
return 0;
/*
* The first byte of the packet we send to the device contains an
* outbound header which indicates an additional number of BOFs and
* a baud rate change.
*
* See section 5.4.2.2 of the USB IrDA spec.
*/
*(u8 *)urb->transfer_buffer = ir_xbof | ir_baud;
memcpy(urb->transfer_buffer + 1, buf, count);
urb->transfer_buffer_length = count + 1;
urb->transfer_flags = URB_ZERO_PACKET;
ret = usb_submit_urb(urb, GFP_ATOMIC);
if (ret) {
dev_err(&port->dev, "failed to submit write urb: %d\n", ret);
spin_lock_irqsave(&port->lock, flags);
__set_bit(0, &port->write_urbs_free);
port->tx_bytes -= count;
spin_unlock_irqrestore(&port->lock, flags);
return ret;
}
return count;
}
static void ir_write_bulk_callback(struct urb *urb)
{
struct usb_serial_port *port = urb->context;
int status = urb->status;
unsigned long flags;
spin_lock_irqsave(&port->lock, flags);
__set_bit(0, &port->write_urbs_free);
port->tx_bytes -= urb->transfer_buffer_length - 1;
spin_unlock_irqrestore(&port->lock, flags);
switch (status) {
case 0:
break;
case -ENOENT:
case -ECONNRESET:
case -ESHUTDOWN:
dev_dbg(&port->dev, "write urb stopped: %d\n", status);
return;
case -EPIPE:
dev_err(&port->dev, "write urb stopped: %d\n", status);
return;
default:
dev_err(&port->dev, "nonzero write-urb status: %d\n", status);
break;
}
usb_serial_port_softint(port);
}
static unsigned int ir_write_room(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
unsigned int count = 0;
if (port->bulk_out_size == 0)
return 0;
if (test_bit(0, &port->write_urbs_free))
count = port->bulk_out_size - 1;
return count;
}
static void ir_process_read_urb(struct urb *urb)
{
struct usb_serial_port *port = urb->context;
unsigned char *data = urb->transfer_buffer;
if (!urb->actual_length)
return;
/*
* The first byte of the packet we get from the device
* contains a busy indicator and baud rate change.
* See section 5.4.1.2 of the USB IrDA spec.
*/
if (*data & 0x0f)
ir_baud = *data & 0x0f;
if (urb->actual_length == 1)
return;
tty_insert_flip_string(&port->port, data + 1, urb->actual_length - 1);
tty_flip_buffer_push(&port->port);
}
static void ir_set_termios(struct tty_struct *tty,
struct usb_serial_port *port,
const struct ktermios *old_termios)
{
struct usb_device *udev = port->serial->dev;
unsigned char *transfer_buffer;
int actual_length;
speed_t baud;
int ir_baud;
int ret;
baud = tty_get_baud_rate(tty);
/*
* FIXME, we should compare the baud request against the
* capability stated in the IR header that we got in the
* startup function.
*/
switch (baud) {
case 2400:
ir_baud = USB_IRDA_LS_2400;
break;
case 9600:
ir_baud = USB_IRDA_LS_9600;
break;
case 19200:
ir_baud = USB_IRDA_LS_19200;
break;
case 38400:
ir_baud = USB_IRDA_LS_38400;
break;
case 57600:
ir_baud = USB_IRDA_LS_57600;
break;
case 115200:
ir_baud = USB_IRDA_LS_115200;
break;
case 576000:
ir_baud = USB_IRDA_LS_576000;
break;
case 1152000:
ir_baud = USB_IRDA_LS_1152000;
break;
case 4000000:
ir_baud = USB_IRDA_LS_4000000;
break;
default:
ir_baud = USB_IRDA_LS_9600;
baud = 9600;
}
if (xbof == -1)
ir_xbof = ir_xbof_change(ir_add_bof);
else
ir_xbof = ir_xbof_change(xbof) ;
/* Only speed changes are supported */
tty_termios_copy_hw(&tty->termios, old_termios);
tty_encode_baud_rate(tty, baud, baud);
/*
* send the baud change out on an "empty" data packet
*/
transfer_buffer = kmalloc(1, GFP_KERNEL);
if (!transfer_buffer)
return;
*transfer_buffer = ir_xbof | ir_baud;
ret = usb_bulk_msg(udev,
usb_sndbulkpipe(udev, port->bulk_out_endpointAddress),
transfer_buffer, 1, &actual_length, 5000);
if (ret || actual_length != 1) {
if (!ret)
ret = -EIO;
dev_err(&port->dev, "failed to change line speed: %d\n", ret);
}
kfree(transfer_buffer);
}
static int __init ir_init(void)
{
if (buffer_size) {
ir_device.bulk_in_size = buffer_size;
ir_device.bulk_out_size = buffer_size;
}
return usb_serial_register_drivers(serial_drivers, KBUILD_MODNAME, ir_id_table);
}
static void __exit ir_exit(void)
{
usb_serial_deregister_drivers(serial_drivers);
}
module_init(ir_init);
module_exit(ir_exit);
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
module_param(xbof, int, 0);
MODULE_PARM_DESC(xbof, "Force specific number of XBOFs");
module_param(buffer_size, int, 0);
MODULE_PARM_DESC(buffer_size, "Size of the transfer buffers");