// SPDX-License-Identifier: GPL-2.0 /* USB Driver layer for GSM modems Copyright (C) 2005 Matthias Urlichs <smurf@smurf.noris.de> Portions copied from the Keyspan driver by Hugh Blemings <hugh@blemings.org> History: see the git log. Work sponsored by: Sigos GmbH, Germany <info@sigos.de> This driver exists because the "normal" serial driver doesn't work too well with GSM modems. Issues: - data loss -- one single Receive URB is not nearly enough - controlling the baud rate doesn't make sense */ #define DRIVER_AUTHOR "Matthias Urlichs <smurf@smurf.noris.de>" #define DRIVER_DESC "USB Driver for GSM modems" #include <linux/kernel.h> #include <linux/jiffies.h> #include <linux/errno.h> #include <linux/slab.h> #include <linux/tty.h> #include <linux/tty_flip.h> #include <linux/module.h> #include <linux/bitops.h> #include <linux/uaccess.h> #include <linux/usb.h> #include <linux/usb/serial.h> #include <linux/serial.h> #include "usb-wwan.h" /* * Generate DTR/RTS signals on the port using the SET_CONTROL_LINE_STATE request * in CDC ACM. */ static int usb_wwan_send_setup(struct usb_serial_port *port) { struct usb_serial *serial = port->serial; struct usb_wwan_port_private *portdata; int val = 0; int ifnum; int res; portdata = usb_get_serial_port_data(port); if (portdata->dtr_state) val |= 0x01; if (portdata->rts_state) val |= 0x02; ifnum = serial->interface->cur_altsetting->desc.bInterfaceNumber; res = usb_autopm_get_interface(serial->interface); if (res) return res; res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0), 0x22, 0x21, val, ifnum, NULL, 0, USB_CTRL_SET_TIMEOUT); usb_autopm_put_interface(port->serial->interface); return res; } void usb_wwan_dtr_rts(struct usb_serial_port *port, int on) { struct usb_wwan_port_private *portdata; struct usb_wwan_intf_private *intfdata; intfdata = usb_get_serial_data(port->serial); if (!intfdata->use_send_setup) return; portdata = usb_get_serial_port_data(port); /* FIXME: locking */ portdata->rts_state = on; portdata->dtr_state = on; usb_wwan_send_setup(port); } EXPORT_SYMBOL(usb_wwan_dtr_rts); int usb_wwan_tiocmget(struct tty_struct *tty) { struct usb_serial_port *port = tty->driver_data; unsigned int value; struct usb_wwan_port_private *portdata; portdata = usb_get_serial_port_data(port); value = ((portdata->rts_state) ? TIOCM_RTS : 0) | ((portdata->dtr_state) ? TIOCM_DTR : 0) | ((portdata->cts_state) ? TIOCM_CTS : 0) | ((portdata->dsr_state) ? TIOCM_DSR : 0) | ((portdata->dcd_state) ? TIOCM_CAR : 0) | ((portdata->ri_state) ? TIOCM_RNG : 0); return value; } EXPORT_SYMBOL(usb_wwan_tiocmget); int usb_wwan_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear) { struct usb_serial_port *port = tty->driver_data; struct usb_wwan_port_private *portdata; struct usb_wwan_intf_private *intfdata; portdata = usb_get_serial_port_data(port); intfdata = usb_get_serial_data(port->serial); if (!intfdata->use_send_setup) return -EINVAL; /* FIXME: what locks portdata fields ? */ if (set & TIOCM_RTS) portdata->rts_state = 1; if (set & TIOCM_DTR) portdata->dtr_state = 1; if (clear & TIOCM_RTS) portdata->rts_state = 0; if (clear & TIOCM_DTR) portdata->dtr_state = 0; return usb_wwan_send_setup(port); } EXPORT_SYMBOL(usb_wwan_tiocmset); int usb_wwan_get_serial_info(struct tty_struct *tty, struct serial_struct *ss) { struct usb_serial_port *port = tty->driver_data; ss->line = port->minor; ss->port = port->port_number; ss->baud_base = tty_get_baud_rate(port->port.tty); ss->close_delay = port->port.close_delay / 10; ss->closing_wait = port->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ? ASYNC_CLOSING_WAIT_NONE : port->port.closing_wait / 10; return 0; } EXPORT_SYMBOL(usb_wwan_get_serial_info); int usb_wwan_set_serial_info(struct tty_struct *tty, struct serial_struct *ss) { struct usb_serial_port *port = tty->driver_data; unsigned int closing_wait, close_delay; int retval = 0; close_delay = ss->close_delay * 10; closing_wait = ss->closing_wait == ASYNC_CLOSING_WAIT_NONE ? ASYNC_CLOSING_WAIT_NONE : ss->closing_wait * 10; mutex_lock(&port->port.mutex); if (!capable(CAP_SYS_ADMIN)) { if ((close_delay != port->port.close_delay) || (closing_wait != port->port.closing_wait)) retval = -EPERM; else retval = -EOPNOTSUPP; } else { port->port.close_delay = close_delay; port->port.closing_wait = closing_wait; } mutex_unlock(&port->port.mutex); return retval; } EXPORT_SYMBOL(usb_wwan_set_serial_info); int usb_wwan_write(struct tty_struct *tty, struct usb_serial_port *port, const unsigned char *buf, int count) { struct usb_wwan_port_private *portdata; struct usb_wwan_intf_private *intfdata; int i; int left, todo; struct urb *this_urb = NULL; /* spurious */ int err; unsigned long flags; portdata = usb_get_serial_port_data(port); intfdata = usb_get_serial_data(port->serial); dev_dbg(&port->dev, "%s: write (%d chars)\n", __func__, count); i = 0; left = count; for (i = 0; left > 0 && i < N_OUT_URB; i++) { todo = left; if (todo > OUT_BUFLEN) todo = OUT_BUFLEN; this_urb = portdata->out_urbs[i]; if (test_and_set_bit(i, &portdata->out_busy)) { if (time_before(jiffies, portdata->tx_start_time[i] + 10 * HZ)) continue; usb_unlink_urb(this_urb); continue; } dev_dbg(&port->dev, "%s: endpoint %d buf %d\n", __func__, usb_pipeendpoint(this_urb->pipe), i); err = usb_autopm_get_interface_async(port->serial->interface); if (err < 0) { clear_bit(i, &portdata->out_busy); break; } /* send the data */ memcpy(this_urb->transfer_buffer, buf, todo); this_urb->transfer_buffer_length = todo; spin_lock_irqsave(&intfdata->susp_lock, flags); if (intfdata->suspended) { usb_anchor_urb(this_urb, &portdata->delayed); spin_unlock_irqrestore(&intfdata->susp_lock, flags); } else { intfdata->in_flight++; spin_unlock_irqrestore(&intfdata->susp_lock, flags); err = usb_submit_urb(this_urb, GFP_ATOMIC); if (err) { dev_err(&port->dev, "%s: submit urb %d failed: %d\n", __func__, i, err); clear_bit(i, &portdata->out_busy); spin_lock_irqsave(&intfdata->susp_lock, flags); intfdata->in_flight--; spin_unlock_irqrestore(&intfdata->susp_lock, flags); usb_autopm_put_interface_async(port->serial->interface); break; } } portdata->tx_start_time[i] = jiffies; buf += todo; left -= todo; } count -= left; dev_dbg(&port->dev, "%s: wrote (did %d)\n", __func__, count); return count; } EXPORT_SYMBOL(usb_wwan_write); static void usb_wwan_indat_callback(struct urb *urb) { int err; int endpoint; struct usb_serial_port *port; struct device *dev; unsigned char *data = urb->transfer_buffer; int status = urb->status; endpoint = usb_pipeendpoint(urb->pipe); port = urb->context; dev = &port->dev; if (status) { dev_dbg(dev, "%s: nonzero status: %d on endpoint %02x.\n", __func__, status, endpoint); } else { if (urb->actual_length) { tty_insert_flip_string(&port->port, data, urb->actual_length); tty_flip_buffer_push(&port->port); } else dev_dbg(dev, "%s: empty read urb received\n", __func__); } /* Resubmit urb so we continue receiving */ err = usb_submit_urb(urb, GFP_ATOMIC); if (err) { if (err != -EPERM && err != -ENODEV) { dev_err(dev, "%s: resubmit read urb failed. (%d)\n", __func__, err); /* busy also in error unless we are killed */ usb_mark_last_busy(port->serial->dev); } } else { usb_mark_last_busy(port->serial->dev); } } static void usb_wwan_outdat_callback(struct urb *urb) { struct usb_serial_port *port; struct usb_wwan_port_private *portdata; struct usb_wwan_intf_private *intfdata; unsigned long flags; int i; port = urb->context; intfdata = usb_get_serial_data(port->serial); usb_serial_port_softint(port); usb_autopm_put_interface_async(port->serial->interface); portdata = usb_get_serial_port_data(port); spin_lock_irqsave(&intfdata->susp_lock, flags); intfdata->in_flight--; spin_unlock_irqrestore(&intfdata->susp_lock, flags); for (i = 0; i < N_OUT_URB; ++i) { if (portdata->out_urbs[i] == urb) { smp_mb__before_atomic(); clear_bit(i, &portdata->out_busy); break; } } } int usb_wwan_write_room(struct tty_struct *tty) { struct usb_serial_port *port = tty->driver_data; struct usb_wwan_port_private *portdata; int i; int data_len = 0; struct urb *this_urb; portdata = usb_get_serial_port_data(port); for (i = 0; i < N_OUT_URB; i++) { this_urb = portdata->out_urbs[i]; if (this_urb && !test_bit(i, &portdata->out_busy)) data_len += OUT_BUFLEN; } dev_dbg(&port->dev, "%s: %d\n", __func__, data_len); return data_len; } EXPORT_SYMBOL(usb_wwan_write_room); int usb_wwan_chars_in_buffer(struct tty_struct *tty) { struct usb_serial_port *port = tty->driver_data; struct usb_wwan_port_private *portdata; int i; int data_len = 0; struct urb *this_urb; portdata = usb_get_serial_port_data(port); for (i = 0; i < N_OUT_URB; i++) { this_urb = portdata->out_urbs[i]; /* FIXME: This locking is insufficient as this_urb may go unused during the test */ if (this_urb && test_bit(i, &portdata->out_busy)) data_len += this_urb->transfer_buffer_length; } dev_dbg(&port->dev, "%s: %d\n", __func__, data_len); return data_len; } EXPORT_SYMBOL(usb_wwan_chars_in_buffer); int usb_wwan_open(struct tty_struct *tty, struct usb_serial_port *port) { struct usb_wwan_port_private *portdata; struct usb_wwan_intf_private *intfdata; struct usb_serial *serial = port->serial; int i, err; struct urb *urb; portdata = usb_get_serial_port_data(port); intfdata = usb_get_serial_data(serial); if (port->interrupt_in_urb) { err = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL); if (err) { dev_err(&port->dev, "%s: submit int urb failed: %d\n", __func__, err); } } /* Start reading from the IN endpoint */ for (i = 0; i < N_IN_URB; i++) { urb = portdata->in_urbs[i]; if (!urb) continue; err = usb_submit_urb(urb, GFP_KERNEL); if (err) { dev_err(&port->dev, "%s: submit read urb %d failed: %d\n", __func__, i, err); } } spin_lock_irq(&intfdata->susp_lock); if (++intfdata->open_ports == 1) serial->interface->needs_remote_wakeup = 1; spin_unlock_irq(&intfdata->susp_lock); /* this balances a get in the generic USB serial code */ usb_autopm_put_interface(serial->interface); return 0; } EXPORT_SYMBOL(usb_wwan_open); static void unbusy_queued_urb(struct urb *urb, struct usb_wwan_port_private *portdata) { int i; for (i = 0; i < N_OUT_URB; i++) { if (urb == portdata->out_urbs[i]) { clear_bit(i, &portdata->out_busy); break; } } } void usb_wwan_close(struct usb_serial_port *port) { int i; struct usb_serial *serial = port->serial; struct usb_wwan_port_private *portdata; struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial); struct urb *urb; portdata = usb_get_serial_port_data(port); /* * Need to take susp_lock to make sure port is not already being * resumed, but no need to hold it due to initialized */ spin_lock_irq(&intfdata->susp_lock); if (--intfdata->open_ports == 0) serial->interface->needs_remote_wakeup = 0; spin_unlock_irq(&intfdata->susp_lock); for (;;) { urb = usb_get_from_anchor(&portdata->delayed); if (!urb) break; unbusy_queued_urb(urb, portdata); usb_autopm_put_interface_async(serial->interface); } for (i = 0; i < N_IN_URB; i++) usb_kill_urb(portdata->in_urbs[i]); for (i = 0; i < N_OUT_URB; i++) usb_kill_urb(portdata->out_urbs[i]); usb_kill_urb(port->interrupt_in_urb); usb_autopm_get_interface_no_resume(serial->interface); } EXPORT_SYMBOL(usb_wwan_close); static struct urb *usb_wwan_setup_urb(struct usb_serial_port *port, int endpoint, int dir, void *ctx, char *buf, int len, void (*callback) (struct urb *)) { struct usb_serial *serial = port->serial; struct urb *urb; urb = usb_alloc_urb(0, GFP_KERNEL); /* No ISO */ if (!urb) return NULL; usb_fill_bulk_urb(urb, serial->dev, usb_sndbulkpipe(serial->dev, endpoint) | dir, buf, len, callback, ctx); return urb; } int usb_wwan_port_probe(struct usb_serial_port *port) { struct usb_wwan_port_private *portdata; struct urb *urb; u8 *buffer; int i; if (!port->bulk_in_size || !port->bulk_out_size) return -ENODEV; portdata = kzalloc(sizeof(*portdata), GFP_KERNEL); if (!portdata) return -ENOMEM; init_usb_anchor(&portdata->delayed); for (i = 0; i < N_IN_URB; i++) { buffer = (u8 *)__get_free_page(GFP_KERNEL); if (!buffer) goto bail_out_error; portdata->in_buffer[i] = buffer; urb = usb_wwan_setup_urb(port, port->bulk_in_endpointAddress, USB_DIR_IN, port, buffer, IN_BUFLEN, usb_wwan_indat_callback); portdata->in_urbs[i] = urb; } for (i = 0; i < N_OUT_URB; i++) { buffer = kmalloc(OUT_BUFLEN, GFP_KERNEL); if (!buffer) goto bail_out_error2; portdata->out_buffer[i] = buffer; urb = usb_wwan_setup_urb(port, port->bulk_out_endpointAddress, USB_DIR_OUT, port, buffer, OUT_BUFLEN, usb_wwan_outdat_callback); portdata->out_urbs[i] = urb; } usb_set_serial_port_data(port, portdata); return 0; bail_out_error2: for (i = 0; i < N_OUT_URB; i++) { usb_free_urb(portdata->out_urbs[i]); kfree(portdata->out_buffer[i]); } bail_out_error: for (i = 0; i < N_IN_URB; i++) { usb_free_urb(portdata->in_urbs[i]); free_page((unsigned long)portdata->in_buffer[i]); } kfree(portdata); return -ENOMEM; } EXPORT_SYMBOL_GPL(usb_wwan_port_probe); int usb_wwan_port_remove(struct usb_serial_port *port) { int i; struct usb_wwan_port_private *portdata; portdata = usb_get_serial_port_data(port); usb_set_serial_port_data(port, NULL); for (i = 0; i < N_IN_URB; i++) { usb_free_urb(portdata->in_urbs[i]); free_page((unsigned long)portdata->in_buffer[i]); } for (i = 0; i < N_OUT_URB; i++) { usb_free_urb(portdata->out_urbs[i]); kfree(portdata->out_buffer[i]); } kfree(portdata); return 0; } EXPORT_SYMBOL(usb_wwan_port_remove); #ifdef CONFIG_PM static void stop_urbs(struct usb_serial *serial) { int i, j; struct usb_serial_port *port; struct usb_wwan_port_private *portdata; for (i = 0; i < serial->num_ports; ++i) { port = serial->port[i]; portdata = usb_get_serial_port_data(port); if (!portdata) continue; for (j = 0; j < N_IN_URB; j++) usb_kill_urb(portdata->in_urbs[j]); for (j = 0; j < N_OUT_URB; j++) usb_kill_urb(portdata->out_urbs[j]); usb_kill_urb(port->interrupt_in_urb); } } int usb_wwan_suspend(struct usb_serial *serial, pm_message_t message) { struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial); spin_lock_irq(&intfdata->susp_lock); if (PMSG_IS_AUTO(message)) { if (intfdata->in_flight) { spin_unlock_irq(&intfdata->susp_lock); return -EBUSY; } } intfdata->suspended = 1; spin_unlock_irq(&intfdata->susp_lock); stop_urbs(serial); return 0; } EXPORT_SYMBOL(usb_wwan_suspend); /* Caller must hold susp_lock. */ static int usb_wwan_submit_delayed_urbs(struct usb_serial_port *port) { struct usb_serial *serial = port->serial; struct usb_wwan_intf_private *data = usb_get_serial_data(serial); struct usb_wwan_port_private *portdata; struct urb *urb; int err_count = 0; int err; portdata = usb_get_serial_port_data(port); for (;;) { urb = usb_get_from_anchor(&portdata->delayed); if (!urb) break; err = usb_submit_urb(urb, GFP_ATOMIC); if (err) { dev_err(&port->dev, "%s: submit urb failed: %d\n", __func__, err); err_count++; unbusy_queued_urb(urb, portdata); usb_autopm_put_interface_async(serial->interface); continue; } data->in_flight++; } if (err_count) return -EIO; return 0; } int usb_wwan_resume(struct usb_serial *serial) { int i, j; struct usb_serial_port *port; struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial); struct usb_wwan_port_private *portdata; struct urb *urb; int err; int err_count = 0; spin_lock_irq(&intfdata->susp_lock); for (i = 0; i < serial->num_ports; i++) { port = serial->port[i]; if (!tty_port_initialized(&port->port)) continue; portdata = usb_get_serial_port_data(port); if (port->interrupt_in_urb) { err = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC); if (err) { dev_err(&port->dev, "%s: submit int urb failed: %d\n", __func__, err); err_count++; } } err = usb_wwan_submit_delayed_urbs(port); if (err) err_count++; for (j = 0; j < N_IN_URB; j++) { urb = portdata->in_urbs[j]; err = usb_submit_urb(urb, GFP_ATOMIC); if (err < 0) { dev_err(&port->dev, "%s: submit read urb %d failed: %d\n", __func__, i, err); err_count++; } } } intfdata->suspended = 0; spin_unlock_irq(&intfdata->susp_lock); if (err_count) return -EIO; return 0; } EXPORT_SYMBOL(usb_wwan_resume); #endif MODULE_AUTHOR(DRIVER_AUTHOR); MODULE_DESCRIPTION(DRIVER_DESC); MODULE_LICENSE("GPL v2");