v4.19.13 snapshot.
diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c
new file mode 100644
index 0000000..2274d96
--- /dev/null
+++ b/drivers/usb/serial/generic.c
@@ -0,0 +1,656 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * USB Serial Converter Generic functions
+ *
+ * Copyright (C) 2010 - 2013 Johan Hovold (jhovold@gmail.com)
+ * Copyright (C) 1999 - 2002 Greg Kroah-Hartman (greg@kroah.com)
+ */
+
+#include <linux/kernel.h>
+#include <linux/sched/signal.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/sysrq.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/usb.h>
+#include <linux/usb/serial.h>
+#include <linux/uaccess.h>
+#include <linux/kfifo.h>
+#include <linux/serial.h>
+
+#ifdef CONFIG_USB_SERIAL_GENERIC
+
+static __u16 vendor = 0x05f9;
+static __u16 product = 0xffff;
+
+module_param(vendor, ushort, 0);
+MODULE_PARM_DESC(vendor, "User specified USB idVendor");
+
+module_param(product, ushort, 0);
+MODULE_PARM_DESC(product, "User specified USB idProduct");
+
+static struct usb_device_id generic_device_ids[2]; /* Initially all zeroes. */
+
+static int usb_serial_generic_probe(struct usb_serial *serial,
+ const struct usb_device_id *id)
+{
+ struct device *dev = &serial->interface->dev;
+
+ dev_info(dev, "The \"generic\" usb-serial driver is only for testing and one-off prototypes.\n");
+ dev_info(dev, "Tell linux-usb@vger.kernel.org to add your device to a proper driver.\n");
+
+ return 0;
+}
+
+static int usb_serial_generic_calc_num_ports(struct usb_serial *serial,
+ struct usb_serial_endpoints *epds)
+{
+ struct device *dev = &serial->interface->dev;
+ int num_ports;
+
+ num_ports = max(epds->num_bulk_in, epds->num_bulk_out);
+
+ if (num_ports == 0) {
+ dev_err(dev, "device has no bulk endpoints\n");
+ return -ENODEV;
+ }
+
+ return num_ports;
+}
+
+static struct usb_serial_driver usb_serial_generic_device = {
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "generic",
+ },
+ .id_table = generic_device_ids,
+ .probe = usb_serial_generic_probe,
+ .calc_num_ports = usb_serial_generic_calc_num_ports,
+ .throttle = usb_serial_generic_throttle,
+ .unthrottle = usb_serial_generic_unthrottle,
+ .resume = usb_serial_generic_resume,
+};
+
+static struct usb_serial_driver * const serial_drivers[] = {
+ &usb_serial_generic_device, NULL
+};
+
+#endif
+
+int usb_serial_generic_register(void)
+{
+ int retval = 0;
+
+#ifdef CONFIG_USB_SERIAL_GENERIC
+ generic_device_ids[0].idVendor = vendor;
+ generic_device_ids[0].idProduct = product;
+ generic_device_ids[0].match_flags =
+ USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT;
+
+ retval = usb_serial_register_drivers(serial_drivers,
+ "usbserial_generic", generic_device_ids);
+#endif
+ return retval;
+}
+
+void usb_serial_generic_deregister(void)
+{
+#ifdef CONFIG_USB_SERIAL_GENERIC
+ usb_serial_deregister_drivers(serial_drivers);
+#endif
+}
+
+int usb_serial_generic_open(struct tty_struct *tty, struct usb_serial_port *port)
+{
+ int result = 0;
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+ port->throttled = 0;
+ port->throttle_req = 0;
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ if (port->bulk_in_size)
+ result = usb_serial_generic_submit_read_urbs(port, GFP_KERNEL);
+
+ return result;
+}
+EXPORT_SYMBOL_GPL(usb_serial_generic_open);
+
+void usb_serial_generic_close(struct usb_serial_port *port)
+{
+ unsigned long flags;
+ int i;
+
+ if (port->bulk_out_size) {
+ for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
+ usb_kill_urb(port->write_urbs[i]);
+
+ spin_lock_irqsave(&port->lock, flags);
+ kfifo_reset_out(&port->write_fifo);
+ spin_unlock_irqrestore(&port->lock, flags);
+ }
+ if (port->bulk_in_size) {
+ for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i)
+ usb_kill_urb(port->read_urbs[i]);
+ }
+}
+EXPORT_SYMBOL_GPL(usb_serial_generic_close);
+
+int usb_serial_generic_prepare_write_buffer(struct usb_serial_port *port,
+ void *dest, size_t size)
+{
+ return kfifo_out_locked(&port->write_fifo, dest, size, &port->lock);
+}
+
+/**
+ * usb_serial_generic_write_start - start writing buffered data
+ * @port: usb-serial port
+ * @mem_flags: flags to use for memory allocations
+ *
+ * Serialised using USB_SERIAL_WRITE_BUSY flag.
+ *
+ * Return: Zero on success or if busy, otherwise a negative errno value.
+ */
+int usb_serial_generic_write_start(struct usb_serial_port *port,
+ gfp_t mem_flags)
+{
+ struct urb *urb;
+ int count, result;
+ unsigned long flags;
+ int i;
+
+ if (test_and_set_bit_lock(USB_SERIAL_WRITE_BUSY, &port->flags))
+ return 0;
+retry:
+ spin_lock_irqsave(&port->lock, flags);
+ if (!port->write_urbs_free || !kfifo_len(&port->write_fifo)) {
+ clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
+ spin_unlock_irqrestore(&port->lock, flags);
+ return 0;
+ }
+ i = (int)find_first_bit(&port->write_urbs_free,
+ ARRAY_SIZE(port->write_urbs));
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ urb = port->write_urbs[i];
+ count = port->serial->type->prepare_write_buffer(port,
+ urb->transfer_buffer,
+ port->bulk_out_size);
+ urb->transfer_buffer_length = count;
+ usb_serial_debug_data(&port->dev, __func__, count, urb->transfer_buffer);
+ spin_lock_irqsave(&port->lock, flags);
+ port->tx_bytes += count;
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ clear_bit(i, &port->write_urbs_free);
+ result = usb_submit_urb(urb, mem_flags);
+ if (result) {
+ dev_err_console(port, "%s - error submitting urb: %d\n",
+ __func__, result);
+ set_bit(i, &port->write_urbs_free);
+ spin_lock_irqsave(&port->lock, flags);
+ port->tx_bytes -= count;
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
+ return result;
+ }
+
+ goto retry; /* try sending off another urb */
+}
+EXPORT_SYMBOL_GPL(usb_serial_generic_write_start);
+
+/**
+ * usb_serial_generic_write - generic write function
+ * @tty: tty for the port
+ * @port: usb-serial port
+ * @buf: data to write
+ * @count: number of bytes to write
+ *
+ * Return: The number of characters buffered, which may be anything from
+ * zero to @count, or a negative errno value.
+ */
+int usb_serial_generic_write(struct tty_struct *tty,
+ struct usb_serial_port *port, const unsigned char *buf, int count)
+{
+ int result;
+
+ if (!port->bulk_out_size)
+ return -ENODEV;
+
+ if (!count)
+ return 0;
+
+ count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
+ result = usb_serial_generic_write_start(port, GFP_ATOMIC);
+ if (result)
+ return result;
+
+ return count;
+}
+EXPORT_SYMBOL_GPL(usb_serial_generic_write);
+
+int usb_serial_generic_write_room(struct tty_struct *tty)
+{
+ struct usb_serial_port *port = tty->driver_data;
+ unsigned long flags;
+ int room;
+
+ if (!port->bulk_out_size)
+ return 0;
+
+ spin_lock_irqsave(&port->lock, flags);
+ room = kfifo_avail(&port->write_fifo);
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ dev_dbg(&port->dev, "%s - returns %d\n", __func__, room);
+ return room;
+}
+
+int usb_serial_generic_chars_in_buffer(struct tty_struct *tty)
+{
+ struct usb_serial_port *port = tty->driver_data;
+ unsigned long flags;
+ int chars;
+
+ if (!port->bulk_out_size)
+ return 0;
+
+ spin_lock_irqsave(&port->lock, flags);
+ chars = kfifo_len(&port->write_fifo) + port->tx_bytes;
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ dev_dbg(&port->dev, "%s - returns %d\n", __func__, chars);
+ return chars;
+}
+EXPORT_SYMBOL_GPL(usb_serial_generic_chars_in_buffer);
+
+void usb_serial_generic_wait_until_sent(struct tty_struct *tty, long timeout)
+{
+ struct usb_serial_port *port = tty->driver_data;
+ unsigned int bps;
+ unsigned long period;
+ unsigned long expire;
+
+ bps = tty_get_baud_rate(tty);
+ if (!bps)
+ bps = 9600; /* B0 */
+ /*
+ * Use a poll-period of roughly the time it takes to send one
+ * character or at least one jiffy.
+ */
+ period = max_t(unsigned long, (10 * HZ / bps), 1);
+ if (timeout)
+ period = min_t(unsigned long, period, timeout);
+
+ dev_dbg(&port->dev, "%s - timeout = %u ms, period = %u ms\n",
+ __func__, jiffies_to_msecs(timeout),
+ jiffies_to_msecs(period));
+ expire = jiffies + timeout;
+ while (!port->serial->type->tx_empty(port)) {
+ schedule_timeout_interruptible(period);
+ if (signal_pending(current))
+ break;
+ if (timeout && time_after(jiffies, expire))
+ break;
+ }
+}
+EXPORT_SYMBOL_GPL(usb_serial_generic_wait_until_sent);
+
+static int usb_serial_generic_submit_read_urb(struct usb_serial_port *port,
+ int index, gfp_t mem_flags)
+{
+ int res;
+
+ if (!test_and_clear_bit(index, &port->read_urbs_free))
+ return 0;
+
+ dev_dbg(&port->dev, "%s - urb %d\n", __func__, index);
+
+ res = usb_submit_urb(port->read_urbs[index], mem_flags);
+ if (res) {
+ if (res != -EPERM && res != -ENODEV) {
+ dev_err(&port->dev,
+ "%s - usb_submit_urb failed: %d\n",
+ __func__, res);
+ }
+ set_bit(index, &port->read_urbs_free);
+ return res;
+ }
+
+ return 0;
+}
+
+int usb_serial_generic_submit_read_urbs(struct usb_serial_port *port,
+ gfp_t mem_flags)
+{
+ int res;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {
+ res = usb_serial_generic_submit_read_urb(port, i, mem_flags);
+ if (res)
+ goto err;
+ }
+
+ return 0;
+err:
+ for (; i >= 0; --i)
+ usb_kill_urb(port->read_urbs[i]);
+
+ return res;
+}
+EXPORT_SYMBOL_GPL(usb_serial_generic_submit_read_urbs);
+
+void usb_serial_generic_process_read_urb(struct urb *urb)
+{
+ struct usb_serial_port *port = urb->context;
+ char *ch = (char *)urb->transfer_buffer;
+ int i;
+
+ if (!urb->actual_length)
+ return;
+ /*
+ * The per character mucking around with sysrq path it too slow for
+ * stuff like 3G modems, so shortcircuit it in the 99.9999999% of
+ * cases where the USB serial is not a console anyway.
+ */
+ if (!port->port.console || !port->sysrq) {
+ tty_insert_flip_string(&port->port, ch, urb->actual_length);
+ } else {
+ for (i = 0; i < urb->actual_length; i++, ch++) {
+ if (!usb_serial_handle_sysrq_char(port, *ch))
+ tty_insert_flip_char(&port->port, *ch, TTY_NORMAL);
+ }
+ }
+ tty_flip_buffer_push(&port->port);
+}
+EXPORT_SYMBOL_GPL(usb_serial_generic_process_read_urb);
+
+void usb_serial_generic_read_bulk_callback(struct urb *urb)
+{
+ struct usb_serial_port *port = urb->context;
+ unsigned char *data = urb->transfer_buffer;
+ unsigned long flags;
+ int status = urb->status;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {
+ if (urb == port->read_urbs[i])
+ break;
+ }
+ set_bit(i, &port->read_urbs_free);
+
+ dev_dbg(&port->dev, "%s - urb %d, len %d\n", __func__, i,
+ urb->actual_length);
+ switch (status) {
+ case 0:
+ break;
+ case -ENOENT:
+ case -ECONNRESET:
+ case -ESHUTDOWN:
+ dev_dbg(&port->dev, "%s - urb stopped: %d\n",
+ __func__, status);
+ return;
+ case -EPIPE:
+ dev_err(&port->dev, "%s - urb stopped: %d\n",
+ __func__, status);
+ return;
+ default:
+ dev_dbg(&port->dev, "%s - nonzero urb status: %d\n",
+ __func__, status);
+ goto resubmit;
+ }
+
+ usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
+ port->serial->type->process_read_urb(urb);
+
+resubmit:
+ /* Throttle the device if requested by tty */
+ spin_lock_irqsave(&port->lock, flags);
+ port->throttled = port->throttle_req;
+ if (!port->throttled) {
+ spin_unlock_irqrestore(&port->lock, flags);
+ usb_serial_generic_submit_read_urb(port, i, GFP_ATOMIC);
+ } else {
+ spin_unlock_irqrestore(&port->lock, flags);
+ }
+}
+EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
+
+void usb_serial_generic_write_bulk_callback(struct urb *urb)
+{
+ unsigned long flags;
+ struct usb_serial_port *port = urb->context;
+ int status = urb->status;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i) {
+ if (port->write_urbs[i] == urb)
+ break;
+ }
+ spin_lock_irqsave(&port->lock, flags);
+ port->tx_bytes -= urb->transfer_buffer_length;
+ set_bit(i, &port->write_urbs_free);
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ switch (status) {
+ case 0:
+ break;
+ case -ENOENT:
+ case -ECONNRESET:
+ case -ESHUTDOWN:
+ dev_dbg(&port->dev, "%s - urb stopped: %d\n",
+ __func__, status);
+ return;
+ case -EPIPE:
+ dev_err_console(port, "%s - urb stopped: %d\n",
+ __func__, status);
+ return;
+ default:
+ dev_err_console(port, "%s - nonzero urb status: %d\n",
+ __func__, status);
+ goto resubmit;
+ }
+
+resubmit:
+ usb_serial_generic_write_start(port, GFP_ATOMIC);
+ usb_serial_port_softint(port);
+}
+EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
+
+void usb_serial_generic_throttle(struct tty_struct *tty)
+{
+ struct usb_serial_port *port = tty->driver_data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+ port->throttle_req = 1;
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+EXPORT_SYMBOL_GPL(usb_serial_generic_throttle);
+
+void usb_serial_generic_unthrottle(struct tty_struct *tty)
+{
+ struct usb_serial_port *port = tty->driver_data;
+ int was_throttled;
+
+ spin_lock_irq(&port->lock);
+ was_throttled = port->throttled;
+ port->throttled = port->throttle_req = 0;
+ spin_unlock_irq(&port->lock);
+
+ if (was_throttled)
+ usb_serial_generic_submit_read_urbs(port, GFP_KERNEL);
+}
+EXPORT_SYMBOL_GPL(usb_serial_generic_unthrottle);
+
+static bool usb_serial_generic_msr_changed(struct tty_struct *tty,
+ unsigned long arg, struct async_icount *cprev)
+{
+ struct usb_serial_port *port = tty->driver_data;
+ struct async_icount cnow;
+ unsigned long flags;
+ bool ret;
+
+ /*
+ * Use tty-port initialised flag to detect all hangups including the
+ * one generated at USB-device disconnect.
+ */
+ if (!tty_port_initialized(&port->port))
+ return true;
+
+ spin_lock_irqsave(&port->lock, flags);
+ cnow = port->icount; /* atomic copy*/
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ ret = ((arg & TIOCM_RNG) && (cnow.rng != cprev->rng)) ||
+ ((arg & TIOCM_DSR) && (cnow.dsr != cprev->dsr)) ||
+ ((arg & TIOCM_CD) && (cnow.dcd != cprev->dcd)) ||
+ ((arg & TIOCM_CTS) && (cnow.cts != cprev->cts));
+
+ *cprev = cnow;
+
+ return ret;
+}
+
+int usb_serial_generic_tiocmiwait(struct tty_struct *tty, unsigned long arg)
+{
+ struct usb_serial_port *port = tty->driver_data;
+ struct async_icount cnow;
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&port->lock, flags);
+ cnow = port->icount; /* atomic copy */
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ ret = wait_event_interruptible(port->port.delta_msr_wait,
+ usb_serial_generic_msr_changed(tty, arg, &cnow));
+ if (!ret && !tty_port_initialized(&port->port))
+ ret = -EIO;
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(usb_serial_generic_tiocmiwait);
+
+int usb_serial_generic_get_icount(struct tty_struct *tty,
+ struct serial_icounter_struct *icount)
+{
+ struct usb_serial_port *port = tty->driver_data;
+ struct async_icount cnow;
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+ cnow = port->icount; /* atomic copy */
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ icount->cts = cnow.cts;
+ icount->dsr = cnow.dsr;
+ icount->rng = cnow.rng;
+ icount->dcd = cnow.dcd;
+ icount->tx = cnow.tx;
+ icount->rx = cnow.rx;
+ icount->frame = cnow.frame;
+ icount->parity = cnow.parity;
+ icount->overrun = cnow.overrun;
+ icount->brk = cnow.brk;
+ icount->buf_overrun = cnow.buf_overrun;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(usb_serial_generic_get_icount);
+
+#ifdef CONFIG_MAGIC_SYSRQ
+int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
+{
+ if (port->sysrq && port->port.console) {
+ if (ch && time_before(jiffies, port->sysrq)) {
+ handle_sysrq(ch);
+ port->sysrq = 0;
+ return 1;
+ }
+ port->sysrq = 0;
+ }
+ return 0;
+}
+#else
+int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
+{
+ return 0;
+}
+#endif
+EXPORT_SYMBOL_GPL(usb_serial_handle_sysrq_char);
+
+int usb_serial_handle_break(struct usb_serial_port *port)
+{
+ if (!port->sysrq) {
+ port->sysrq = jiffies + HZ*5;
+ return 1;
+ }
+ port->sysrq = 0;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(usb_serial_handle_break);
+
+/**
+ * usb_serial_handle_dcd_change - handle a change of carrier detect state
+ * @port: usb-serial port
+ * @tty: tty for the port
+ * @status: new carrier detect status, nonzero if active
+ */
+void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port,
+ struct tty_struct *tty, unsigned int status)
+{
+ struct tty_port *port = &usb_port->port;
+
+ dev_dbg(&usb_port->dev, "%s - status %d\n", __func__, status);
+
+ if (tty) {
+ struct tty_ldisc *ld = tty_ldisc_ref(tty);
+
+ if (ld) {
+ if (ld->ops->dcd_change)
+ ld->ops->dcd_change(tty, status);
+ tty_ldisc_deref(ld);
+ }
+ }
+
+ if (status)
+ wake_up_interruptible(&port->open_wait);
+ else if (tty && !C_CLOCAL(tty))
+ tty_hangup(tty);
+}
+EXPORT_SYMBOL_GPL(usb_serial_handle_dcd_change);
+
+int usb_serial_generic_resume(struct usb_serial *serial)
+{
+ struct usb_serial_port *port;
+ int i, c = 0, r;
+
+ for (i = 0; i < serial->num_ports; i++) {
+ port = serial->port[i];
+ if (!tty_port_initialized(&port->port))
+ continue;
+
+ if (port->bulk_in_size) {
+ r = usb_serial_generic_submit_read_urbs(port,
+ GFP_NOIO);
+ if (r < 0)
+ c++;
+ }
+
+ if (port->bulk_out_size) {
+ r = usb_serial_generic_write_start(port, GFP_NOIO);
+ if (r < 0)
+ c++;
+ }
+ }
+
+ return c ? -EIO : 0;
+}
+EXPORT_SYMBOL_GPL(usb_serial_generic_resume);