1 files changed, 658 insertions, 0 deletions

diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c
new file mode 100644
index 0000000000..15b6dee3a8
--- /dev/null
+++ b/drivers/usb/serial/generic.c
@@ -0,0 +1,658 @@
+// 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;
+
+	clear_bit(USB_SERIAL_THROTTLED, &port->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);
+
+unsigned int usb_serial_generic_write_room(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	unsigned long flags;
+	unsigned 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 %u\n", __func__, room);
+	return room;
+}
+
+unsigned int usb_serial_generic_chars_in_buffer(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	unsigned long flags;
+	unsigned 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 %u\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 = 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->sysrq) {
+		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);
+		}
+	} else {
+		tty_insert_flip_string(&port->port, ch, urb->actual_length);
+	}
+	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;
+	bool stopped = false;
+	int status = urb->status;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {
+		if (urb == port->read_urbs[i])
+			break;
+	}
+
+	dev_dbg(&port->dev, "%s - urb %d, len %d\n", __func__, i,
+							urb->actual_length);
+	switch (status) {
+	case 0:
+		usb_serial_debug_data(&port->dev, __func__, urb->actual_length,
+							data);
+		port->serial->type->process_read_urb(urb);
+		break;
+	case -ENOENT:
+	case -ECONNRESET:
+	case -ESHUTDOWN:
+		dev_dbg(&port->dev, "%s - urb stopped: %d\n",
+							__func__, status);
+		stopped = true;
+		break;
+	case -EPIPE:
+		dev_err(&port->dev, "%s - urb stopped: %d\n",
+							__func__, status);
+		stopped = true;
+		break;
+	default:
+		dev_dbg(&port->dev, "%s - nonzero urb status: %d\n",
+							__func__, status);
+		break;
+	}
+
+	/*
+	 * Make sure URB processing is done before marking as free to avoid
+	 * racing with unthrottle() on another CPU. Matches the barriers
+	 * implied by the test_and_clear_bit() in
+	 * usb_serial_generic_submit_read_urb().
+	 */
+	smp_mb__before_atomic();
+	set_bit(i, &port->read_urbs_free);
+	/*
+	 * Make sure URB is marked as free before checking the throttled flag
+	 * to avoid racing with unthrottle() on another CPU. Matches the
+	 * smp_mb__after_atomic() in unthrottle().
+	 */
+	smp_mb__after_atomic();
+
+	if (stopped)
+		return;
+
+	if (test_bit(USB_SERIAL_THROTTLED, &port->flags))
+		return;
+
+	usb_serial_generic_submit_read_urb(port, i, GFP_ATOMIC);
+}
+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);
+		break;
+	}
+
+	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;
+
+	set_bit(USB_SERIAL_THROTTLED, &port->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;
+
+	clear_bit(USB_SERIAL_THROTTLED, &port->flags);
+
+	/*
+	 * Matches the smp_mb__after_atomic() in
+	 * usb_serial_generic_read_bulk_callback().
+	 */
+	smp_mb__after_atomic();
+
+	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);
+
+#if defined(CONFIG_USB_SERIAL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
+{
+	if (port->sysrq) {
+		if (ch && time_before(jiffies, port->sysrq)) {
+			handle_sysrq(ch);
+			port->sysrq = 0;
+			return 1;
+		}
+		port->sysrq = 0;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(usb_serial_handle_sysrq_char);
+
+int usb_serial_handle_break(struct usb_serial_port *port)
+{
+	if (!port->port.console)
+		return 0;
+
+	if (!port->sysrq) {
+		port->sysrq = jiffies + HZ*5;
+		return 1;
+	}
+	port->sysrq = 0;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(usb_serial_handle_break);
+#endif
+
+/**
+ * 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 *port,
+				struct tty_struct *tty, unsigned int status)
+{
+	dev_dbg(&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->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);