// SPDX-License-Identifier: GPL-2.0
/*
USB Driver layer for GSM modems
Copyright (C) 2005 Matthias Urlichs <[email protected]>
Portions copied from the Keyspan driver by Hugh Blemings <[email protected]>
History: see the git log.
Work sponsored by: Sigos GmbH, Germany <[email protected]>
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 <[email protected]>"
#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/cdc.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 |= USB_CDC_CTRL_DTR;
if (portdata->rts_state)
val |= USB_CDC_CTRL_RTS;
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),
USB_CDC_REQ_SET_CONTROL_LINE_STATE,
USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
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_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);
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);
/* don't resubmit on fatal errors */
if (status == -ESHUTDOWN || status == -ENOENT)
return;
} 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;
}
}
}
unsigned 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;
unsigned 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: %u\n", __func__, data_len);
return data_len;
}
EXPORT_SYMBOL(usb_wwan_write_room);
unsigned 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;
unsigned 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: %u\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 the tty-port initialized
* flag.
*/
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 usb_wwan_intf_private *intfdata = usb_get_serial_data(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);
if (intfdata->use_zlp && dir == USB_DIR_OUT)
urb->transfer_flags |= URB_ZERO_PACKET;
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);
void 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);
}
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");
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