diff options
Diffstat (limited to 'drivers/usb/serial/opticon.c')
-rw-r--r-- | drivers/usb/serial/opticon.c | 406 |
1 files changed, 406 insertions, 0 deletions
diff --git a/drivers/usb/serial/opticon.c b/drivers/usb/serial/opticon.c new file mode 100644 index 0000000000..e31a6d77da --- /dev/null +++ b/drivers/usb/serial/opticon.c @@ -0,0 +1,406 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Opticon USB barcode to serial driver + * + * Copyright (C) 2011 - 2012 Johan Hovold <jhovold@gmail.com> + * Copyright (C) 2011 Martin Jansen <martin.jansen@opticon.com> + * Copyright (C) 2008 - 2009 Greg Kroah-Hartman <gregkh@suse.de> + * Copyright (C) 2008 - 2009 Novell Inc. + */ + +#include <linux/kernel.h> +#include <linux/tty.h> +#include <linux/tty_driver.h> +#include <linux/slab.h> +#include <linux/tty_flip.h> +#include <linux/serial.h> +#include <linux/module.h> +#include <linux/usb.h> +#include <linux/usb/serial.h> +#include <linux/uaccess.h> + +#define CONTROL_RTS 0x02 +#define RESEND_CTS_STATE 0x03 + +/* max number of write urbs in flight */ +#define URB_UPPER_LIMIT 8 + +/* This driver works for the Opticon 1D barcode reader + * an examples of 1D barcode types are EAN, UPC, Code39, IATA etc.. */ +#define DRIVER_DESC "Opticon USB barcode to serial driver (1D)" + +static const struct usb_device_id id_table[] = { + { USB_DEVICE(0x065a, 0x0009) }, + { }, +}; +MODULE_DEVICE_TABLE(usb, id_table); + +/* This structure holds all of the individual device information */ +struct opticon_private { + spinlock_t lock; /* protects the following flags */ + bool rts; + bool cts; + int outstanding_urbs; + int outstanding_bytes; + + struct usb_anchor anchor; +}; + + +static void opticon_process_data_packet(struct usb_serial_port *port, + const unsigned char *buf, size_t len) +{ + tty_insert_flip_string(&port->port, buf, len); + tty_flip_buffer_push(&port->port); +} + +static void opticon_process_status_packet(struct usb_serial_port *port, + const unsigned char *buf, size_t len) +{ + struct opticon_private *priv = usb_get_serial_port_data(port); + unsigned long flags; + + spin_lock_irqsave(&priv->lock, flags); + if (buf[0] == 0x00) + priv->cts = false; + else + priv->cts = true; + spin_unlock_irqrestore(&priv->lock, flags); +} + +static void opticon_process_read_urb(struct urb *urb) +{ + struct usb_serial_port *port = urb->context; + const unsigned char *hdr = urb->transfer_buffer; + const unsigned char *data = hdr + 2; + size_t data_len = urb->actual_length - 2; + + if (urb->actual_length <= 2) { + dev_dbg(&port->dev, "malformed packet received: %d bytes\n", + urb->actual_length); + return; + } + /* + * Data from the device comes with a 2 byte header: + * + * <0x00><0x00>data... + * This is real data to be sent to the tty layer + * <0x00><0x01>level + * This is a CTS level change, the third byte is the CTS + * value (0 for low, 1 for high). + */ + if ((hdr[0] == 0x00) && (hdr[1] == 0x00)) { + opticon_process_data_packet(port, data, data_len); + } else if ((hdr[0] == 0x00) && (hdr[1] == 0x01)) { + opticon_process_status_packet(port, data, data_len); + } else { + dev_dbg(&port->dev, "unknown packet received: %02x %02x\n", + hdr[0], hdr[1]); + } +} + +static int send_control_msg(struct usb_serial_port *port, u8 requesttype, + u8 val) +{ + struct usb_serial *serial = port->serial; + int retval; + u8 *buffer; + + buffer = kzalloc(1, GFP_KERNEL); + if (!buffer) + return -ENOMEM; + + buffer[0] = val; + /* Send the message to the vendor control endpoint + * of the connected device */ + retval = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0), + requesttype, + USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE, + 0, 0, buffer, 1, USB_CTRL_SET_TIMEOUT); + kfree(buffer); + + if (retval < 0) + return retval; + + return 0; +} + +static int opticon_open(struct tty_struct *tty, struct usb_serial_port *port) +{ + struct opticon_private *priv = usb_get_serial_port_data(port); + unsigned long flags; + int res; + + spin_lock_irqsave(&priv->lock, flags); + priv->rts = false; + spin_unlock_irqrestore(&priv->lock, flags); + + /* Clear RTS line */ + send_control_msg(port, CONTROL_RTS, 0); + + /* clear the halt status of the endpoint */ + usb_clear_halt(port->serial->dev, port->read_urb->pipe); + + res = usb_serial_generic_open(tty, port); + if (res) + return res; + + /* Request CTS line state, sometimes during opening the current + * CTS state can be missed. */ + send_control_msg(port, RESEND_CTS_STATE, 1); + + return res; +} + +static void opticon_close(struct usb_serial_port *port) +{ + struct opticon_private *priv = usb_get_serial_port_data(port); + + usb_kill_anchored_urbs(&priv->anchor); + + usb_serial_generic_close(port); +} + +static void opticon_write_control_callback(struct urb *urb) +{ + struct usb_serial_port *port = urb->context; + struct opticon_private *priv = usb_get_serial_port_data(port); + int status = urb->status; + unsigned long flags; + + /* free up the transfer buffer, as usb_free_urb() does not do this */ + kfree(urb->transfer_buffer); + + /* setup packet may be set if we're using it for writing */ + kfree(urb->setup_packet); + + if (status) + dev_dbg(&port->dev, + "%s - non-zero urb status received: %d\n", + __func__, status); + + spin_lock_irqsave(&priv->lock, flags); + --priv->outstanding_urbs; + priv->outstanding_bytes -= urb->transfer_buffer_length; + spin_unlock_irqrestore(&priv->lock, flags); + + usb_serial_port_softint(port); +} + +static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port, + const unsigned char *buf, int count) +{ + struct opticon_private *priv = usb_get_serial_port_data(port); + struct usb_serial *serial = port->serial; + struct urb *urb; + unsigned char *buffer; + unsigned long flags; + struct usb_ctrlrequest *dr; + int ret = -ENOMEM; + + spin_lock_irqsave(&priv->lock, flags); + if (priv->outstanding_urbs > URB_UPPER_LIMIT) { + spin_unlock_irqrestore(&priv->lock, flags); + dev_dbg(&port->dev, "%s - write limit hit\n", __func__); + return 0; + } + priv->outstanding_urbs++; + priv->outstanding_bytes += count; + spin_unlock_irqrestore(&priv->lock, flags); + + buffer = kmemdup(buf, count, GFP_ATOMIC); + if (!buffer) + goto error_no_buffer; + + urb = usb_alloc_urb(0, GFP_ATOMIC); + if (!urb) + goto error_no_urb; + + usb_serial_debug_data(&port->dev, __func__, count, buffer); + + /* The connected devices do not have a bulk write endpoint, + * to transmit data to de barcode device the control endpoint is used */ + dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC); + if (!dr) + goto error_no_dr; + + dr->bRequestType = USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT; + dr->bRequest = 0x01; + dr->wValue = 0; + dr->wIndex = 0; + dr->wLength = cpu_to_le16(count); + + usb_fill_control_urb(urb, serial->dev, + usb_sndctrlpipe(serial->dev, 0), + (unsigned char *)dr, buffer, count, + opticon_write_control_callback, port); + + usb_anchor_urb(urb, &priv->anchor); + + /* send it down the pipe */ + ret = usb_submit_urb(urb, GFP_ATOMIC); + if (ret) { + dev_err(&port->dev, "failed to submit write urb: %d\n", ret); + usb_unanchor_urb(urb); + goto error; + } + + /* we are done with this urb, so let the host driver + * really free it when it is finished with it */ + usb_free_urb(urb); + + return count; +error: + kfree(dr); +error_no_dr: + usb_free_urb(urb); +error_no_urb: + kfree(buffer); +error_no_buffer: + spin_lock_irqsave(&priv->lock, flags); + --priv->outstanding_urbs; + priv->outstanding_bytes -= count; + spin_unlock_irqrestore(&priv->lock, flags); + + return ret; +} + +static unsigned int opticon_write_room(struct tty_struct *tty) +{ + struct usb_serial_port *port = tty->driver_data; + struct opticon_private *priv = usb_get_serial_port_data(port); + unsigned long flags; + + /* + * We really can take almost anything the user throws at us + * but let's pick a nice big number to tell the tty + * layer that we have lots of free space, unless we don't. + */ + spin_lock_irqsave(&priv->lock, flags); + if (priv->outstanding_urbs > URB_UPPER_LIMIT * 2 / 3) { + spin_unlock_irqrestore(&priv->lock, flags); + dev_dbg(&port->dev, "%s - write limit hit\n", __func__); + return 0; + } + spin_unlock_irqrestore(&priv->lock, flags); + + return 2048; +} + +static unsigned int opticon_chars_in_buffer(struct tty_struct *tty) +{ + struct usb_serial_port *port = tty->driver_data; + struct opticon_private *priv = usb_get_serial_port_data(port); + unsigned long flags; + unsigned int count; + + spin_lock_irqsave(&priv->lock, flags); + count = priv->outstanding_bytes; + spin_unlock_irqrestore(&priv->lock, flags); + + return count; +} + +static int opticon_tiocmget(struct tty_struct *tty) +{ + struct usb_serial_port *port = tty->driver_data; + struct opticon_private *priv = usb_get_serial_port_data(port); + unsigned long flags; + int result = 0; + + spin_lock_irqsave(&priv->lock, flags); + if (priv->rts) + result |= TIOCM_RTS; + if (priv->cts) + result |= TIOCM_CTS; + spin_unlock_irqrestore(&priv->lock, flags); + + dev_dbg(&port->dev, "%s - %x\n", __func__, result); + return result; +} + +static int opticon_tiocmset(struct tty_struct *tty, + unsigned int set, unsigned int clear) +{ + struct usb_serial_port *port = tty->driver_data; + struct opticon_private *priv = usb_get_serial_port_data(port); + unsigned long flags; + bool rts; + bool changed = false; + int ret; + + /* We only support RTS so we only handle that */ + spin_lock_irqsave(&priv->lock, flags); + + rts = priv->rts; + if (set & TIOCM_RTS) + priv->rts = true; + if (clear & TIOCM_RTS) + priv->rts = false; + changed = rts ^ priv->rts; + spin_unlock_irqrestore(&priv->lock, flags); + + if (!changed) + return 0; + + ret = send_control_msg(port, CONTROL_RTS, !rts); + if (ret) + return usb_translate_errors(ret); + + return 0; +} + +static int opticon_port_probe(struct usb_serial_port *port) +{ + struct opticon_private *priv; + + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + spin_lock_init(&priv->lock); + init_usb_anchor(&priv->anchor); + + usb_set_serial_port_data(port, priv); + + return 0; +} + +static void opticon_port_remove(struct usb_serial_port *port) +{ + struct opticon_private *priv = usb_get_serial_port_data(port); + + kfree(priv); +} + +static struct usb_serial_driver opticon_device = { + .driver = { + .owner = THIS_MODULE, + .name = "opticon", + }, + .id_table = id_table, + .num_ports = 1, + .num_bulk_in = 1, + .bulk_in_size = 256, + .port_probe = opticon_port_probe, + .port_remove = opticon_port_remove, + .open = opticon_open, + .close = opticon_close, + .write = opticon_write, + .write_room = opticon_write_room, + .chars_in_buffer = opticon_chars_in_buffer, + .throttle = usb_serial_generic_throttle, + .unthrottle = usb_serial_generic_unthrottle, + .tiocmget = opticon_tiocmget, + .tiocmset = opticon_tiocmset, + .process_read_urb = opticon_process_read_urb, +}; + +static struct usb_serial_driver * const serial_drivers[] = { + &opticon_device, NULL +}; + +module_usb_serial_driver(serial_drivers, id_table); + +MODULE_DESCRIPTION(DRIVER_DESC); +MODULE_LICENSE("GPL v2"); |