[linux-2.6-block.git] / drivers / usb / serial / ch341.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright 2007, Frank A Kingswood <frank@kingswood-consulting.co.uk>
 * Copyright 2007, Werner Cornelius <werner@cornelius-consult.de>
 * Copyright 2009, Boris Hajduk <boris@hajduk.org>
 *
 * ch341.c implements a serial port driver for the Winchiphead CH341.
 *
 * The CH341 device can be used to implement an RS232 asynchronous
 * serial port, an IEEE-1284 parallel printer port or a memory-like
 * interface. In all cases the CH341 supports an I2C interface as well.
 * This driver only supports the asynchronous serial interface.
 */

#include <linux/kernel.h>
#include <linux/tty.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <linux/serial.h>
#include <asm/unaligned.h>

#define DEFAULT_BAUD_RATE 9600
#define DEFAULT_TIMEOUT   1000

/* flags for IO-Bits */
#define CH341_BIT_RTS (1 << 6)
#define CH341_BIT_DTR (1 << 5)

/******************************/
/* interrupt pipe definitions */
/******************************/
/* always 4 interrupt bytes */
/* first irq byte normally 0x08 */
/* second irq byte base 0x7d + below */
/* third irq byte base 0x94 + below */
/* fourth irq byte normally 0xee */

/* second interrupt byte */
#define CH341_MULT_STAT 0x04 /* multiple status since last interrupt event */

/* status returned in third interrupt answer byte, inverted in data
   from irq */
#define CH341_BIT_CTS 0x01
#define CH341_BIT_DSR 0x02
#define CH341_BIT_RI  0x04
#define CH341_BIT_DCD 0x08
#define CH341_BITS_MODEM_STAT 0x0f /* all bits */

/*******************************/
/* baudrate calculation factor */
/*******************************/
#define CH341_BAUDBASE_FACTOR 1532620800
#define CH341_BAUDBASE_DIVMAX 3

/* Break support - the information used to implement this was gleaned from
 * the Net/FreeBSD uchcom.c driver by Takanori Watanabe.  Domo arigato.
 */

#define CH341_REQ_READ_VERSION 0x5F
#define CH341_REQ_WRITE_REG    0x9A
#define CH341_REQ_READ_REG     0x95
#define CH341_REQ_SERIAL_INIT  0xA1
#define CH341_REQ_MODEM_CTRL   0xA4

#define CH341_REG_BREAK        0x05
#define CH341_REG_LCR          0x18
#define CH341_NBREAK_BITS      0x01

#define CH341_LCR_ENABLE_RX    0x80
#define CH341_LCR_ENABLE_TX    0x40
#define CH341_LCR_MARK_SPACE   0x20
#define CH341_LCR_PAR_EVEN     0x10
#define CH341_LCR_ENABLE_PAR   0x08
#define CH341_LCR_STOP_BITS_2  0x04
#define CH341_LCR_CS8          0x03
#define CH341_LCR_CS7          0x02
#define CH341_LCR_CS6          0x01
#define CH341_LCR_CS5          0x00

static const struct usb_device_id id_table[] = {
	{ USB_DEVICE(0x4348, 0x5523) },
	{ USB_DEVICE(0x1a86, 0x7523) },
	{ USB_DEVICE(0x1a86, 0x5523) },
	{ },
};
MODULE_DEVICE_TABLE(usb, id_table);

struct ch341_private {
	spinlock_t lock; /* access lock */
	unsigned baud_rate; /* set baud rate */
	u8 mcr;
	u8 msr;
	u8 lcr;
};

static void ch341_set_termios(struct tty_struct *tty,
			      struct usb_serial_port *port,
			      struct ktermios *old_termios);

static int ch341_control_out(struct usb_device *dev, u8 request,
			     u16 value, u16 index)
{
	int r;

	dev_dbg(&dev->dev, "%s - (%02x,%04x,%04x)\n", __func__,
		request, value, index);

	r = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request,
			    USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
			    value, index, NULL, 0, DEFAULT_TIMEOUT);
	if (r < 0)
		dev_err(&dev->dev, "failed to send control message: %d\n", r);

	return r;
}

static int ch341_control_in(struct usb_device *dev,
			    u8 request, u16 value, u16 index,
			    char *buf, unsigned bufsize)
{
	int r;

	dev_dbg(&dev->dev, "%s - (%02x,%04x,%04x,%u)\n", __func__,
		request, value, index, bufsize);

	r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request,
			    USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
			    value, index, buf, bufsize, DEFAULT_TIMEOUT);
	if (r < (int)bufsize) {
		if (r >= 0) {
			dev_err(&dev->dev,
				"short control message received (%d < %u)\n",
				r, bufsize);
			r = -EIO;
		}

		dev_err(&dev->dev, "failed to receive control message: %d\n",
			r);
		return r;
	}

	return 0;
}

static int ch341_set_baudrate_lcr(struct usb_device *dev,
				  struct ch341_private *priv, u8 lcr)
{
	short a;
	int r;
	unsigned long factor;
	short divisor;

	if (!priv->baud_rate)
		return -EINVAL;
	factor = (CH341_BAUDBASE_FACTOR / priv->baud_rate);
	divisor = CH341_BAUDBASE_DIVMAX;

	while ((factor > 0xfff0) && divisor) {
		factor >>= 3;
		divisor--;
	}

	if (factor > 0xfff0)
		return -EINVAL;

	factor = 0x10000 - factor;
	a = (factor & 0xff00) | divisor;

	/*
	 * CH341A buffers data until a full endpoint-size packet (32 bytes)
	 * has been received unless bit 7 is set.
	 */
	a |= BIT(7);

	r = ch341_control_out(dev, CH341_REQ_WRITE_REG, 0x1312, a);
	if (r)
		return r;

	r = ch341_control_out(dev, CH341_REQ_WRITE_REG, 0x2518, lcr);
	if (r)
		return r;

	return r;
}

static int ch341_set_handshake(struct usb_device *dev, u8 control)
{
	return ch341_control_out(dev, CH341_REQ_MODEM_CTRL, ~control, 0);
}

static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
{
	const unsigned int size = 2;
	char *buffer;
	int r;
	unsigned long flags;

	buffer = kmalloc(size, GFP_KERNEL);
	if (!buffer)
		return -ENOMEM;

	r = ch341_control_in(dev, CH341_REQ_READ_REG, 0x0706, 0, buffer, size);
	if (r < 0)
		goto out;

	spin_lock_irqsave(&priv->lock, flags);
	priv->msr = (~(*buffer)) & CH341_BITS_MODEM_STAT;
	spin_unlock_irqrestore(&priv->lock, flags);

out:	kfree(buffer);
	return r;
}

/* -------------------------------------------------------------------------- */

static int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
{
	const unsigned int size = 2;
	char *buffer;
	int r;

	buffer = kmalloc(size, GFP_KERNEL);
	if (!buffer)
		return -ENOMEM;

	/* expect two bytes 0x27 0x00 */
	r = ch341_control_in(dev, CH341_REQ_READ_VERSION, 0, 0, buffer, size);
	if (r < 0)
		goto out;
	dev_dbg(&dev->dev, "Chip version: 0x%02x\n", buffer[0]);

	r = ch341_control_out(dev, CH341_REQ_SERIAL_INIT, 0, 0);
	if (r < 0)
		goto out;

	r = ch341_set_baudrate_lcr(dev, priv, priv->lcr);
	if (r < 0)
		goto out;

	r = ch341_set_handshake(dev, priv->mcr);

out:	kfree(buffer);
	return r;
}

static int ch341_port_probe(struct usb_serial_port *port)
{
	struct ch341_private *priv;
	int r;

	priv = kzalloc(sizeof(struct ch341_private), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	spin_lock_init(&priv->lock);
	priv->baud_rate = DEFAULT_BAUD_RATE;
	/*
	 * Some CH340 devices appear unable to change the initial LCR
	 * settings, so set a sane 8N1 default.
	 */
	priv->lcr = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX | CH341_LCR_CS8;

	r = ch341_configure(port->serial->dev, priv);
	if (r < 0)
		goto error;

	usb_set_serial_port_data(port, priv);
	return 0;

error:	kfree(priv);
	return r;
}

static int ch341_port_remove(struct usb_serial_port *port)
{
	struct ch341_private *priv;

	priv = usb_get_serial_port_data(port);
	kfree(priv);

	return 0;
}

static int ch341_carrier_raised(struct usb_serial_port *port)
{
	struct ch341_private *priv = usb_get_serial_port_data(port);
	if (priv->msr & CH341_BIT_DCD)
		return 1;
	return 0;
}

static void ch341_dtr_rts(struct usb_serial_port *port, int on)
{
	struct ch341_private *priv = usb_get_serial_port_data(port);
	unsigned long flags;

	/* drop DTR and RTS */
	spin_lock_irqsave(&priv->lock, flags);
	if (on)
		priv->mcr |= CH341_BIT_RTS | CH341_BIT_DTR;
	else
		priv->mcr &= ~(CH341_BIT_RTS | CH341_BIT_DTR);
	spin_unlock_irqrestore(&priv->lock, flags);
	ch341_set_handshake(port->serial->dev, priv->mcr);
}

static void ch341_close(struct usb_serial_port *port)
{
	usb_serial_generic_close(port);
	usb_kill_urb(port->interrupt_in_urb);
}


/* open this device, set default parameters */
static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port)
{
	struct ch341_private *priv = usb_get_serial_port_data(port);
	int r;

	if (tty)
		ch341_set_termios(tty, port, NULL);

	dev_dbg(&port->dev, "%s - submitting interrupt urb\n", __func__);
	r = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
	if (r) {
		dev_err(&port->dev, "%s - failed to submit interrupt urb: %d\n",
			__func__, r);
		return r;
	}

	r = ch341_get_status(port->serial->dev, priv);
	if (r < 0) {
		dev_err(&port->dev, "failed to read modem status: %d\n", r);
		goto err_kill_interrupt_urb;
	}

	r = usb_serial_generic_open(tty, port);
	if (r)
		goto err_kill_interrupt_urb;

	return 0;

err_kill_interrupt_urb:
	usb_kill_urb(port->interrupt_in_urb);

	return r;
}

/* Old_termios contains the original termios settings and
 * tty->termios contains the new setting to be used.
 */
static void ch341_set_termios(struct tty_struct *tty,
		struct usb_serial_port *port, struct ktermios *old_termios)
{
	struct ch341_private *priv = usb_get_serial_port_data(port);
	unsigned baud_rate;
	unsigned long flags;
	u8 lcr;
	int r;

	/* redundant changes may cause the chip to lose bytes */
	if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
		return;

	baud_rate = tty_get_baud_rate(tty);

	lcr = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX;

	switch (C_CSIZE(tty)) {
	case CS5:
		lcr |= CH341_LCR_CS5;
		break;
	case CS6:
		lcr |= CH341_LCR_CS6;
		break;
	case CS7:
		lcr |= CH341_LCR_CS7;
		break;
	case CS8:
		lcr |= CH341_LCR_CS8;
		break;
	}

	if (C_PARENB(tty)) {
		lcr |= CH341_LCR_ENABLE_PAR;
		if (C_PARODD(tty) == 0)
			lcr |= CH341_LCR_PAR_EVEN;
		if (C_CMSPAR(tty))
			lcr |= CH341_LCR_MARK_SPACE;
	}

	if (C_CSTOPB(tty))
		lcr |= CH341_LCR_STOP_BITS_2;

	if (baud_rate) {
		priv->baud_rate = baud_rate;

		r = ch341_set_baudrate_lcr(port->serial->dev, priv, lcr);
		if (r < 0 && old_termios) {
			priv->baud_rate = tty_termios_baud_rate(old_termios);
			tty_termios_copy_hw(&tty->termios, old_termios);
		} else if (r == 0) {
			priv->lcr = lcr;
		}
	}

	spin_lock_irqsave(&priv->lock, flags);
	if (C_BAUD(tty) == B0)
		priv->mcr &= ~(CH341_BIT_DTR | CH341_BIT_RTS);
	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
		priv->mcr |= (CH341_BIT_DTR | CH341_BIT_RTS);
	spin_unlock_irqrestore(&priv->lock, flags);

	ch341_set_handshake(port->serial->dev, priv->mcr);
}

static void ch341_break_ctl(struct tty_struct *tty, int break_state)
{
	const uint16_t ch341_break_reg =
			((uint16_t) CH341_REG_LCR << 8) | CH341_REG_BREAK;
	struct usb_serial_port *port = tty->driver_data;
	int r;
	uint16_t reg_contents;
	uint8_t *break_reg;

	break_reg = kmalloc(2, GFP_KERNEL);
	if (!break_reg)
		return;

	r = ch341_control_in(port->serial->dev, CH341_REQ_READ_REG,
			ch341_break_reg, 0, break_reg, 2);
	if (r < 0) {
		dev_err(&port->dev, "%s - USB control read error (%d)\n",
				__func__, r);
		goto out;
	}
	dev_dbg(&port->dev, "%s - initial ch341 break register contents - reg1: %x, reg2: %x\n",
		__func__, break_reg[0], break_reg[1]);
	if (break_state != 0) {
		dev_dbg(&port->dev, "%s - Enter break state requested\n", __func__);
		break_reg[0] &= ~CH341_NBREAK_BITS;
		break_reg[1] &= ~CH341_LCR_ENABLE_TX;
	} else {
		dev_dbg(&port->dev, "%s - Leave break state requested\n", __func__);
		break_reg[0] |= CH341_NBREAK_BITS;
		break_reg[1] |= CH341_LCR_ENABLE_TX;
	}
	dev_dbg(&port->dev, "%s - New ch341 break register contents - reg1: %x, reg2: %x\n",
		__func__, break_reg[0], break_reg[1]);
	reg_contents = get_unaligned_le16(break_reg);
	r = ch341_control_out(port->serial->dev, CH341_REQ_WRITE_REG,
			ch341_break_reg, reg_contents);
	if (r < 0)
		dev_err(&port->dev, "%s - USB control write error (%d)\n",
				__func__, r);
out:
	kfree(break_reg);
}

static int ch341_tiocmset(struct tty_struct *tty,
			  unsigned int set, unsigned int clear)
{
	struct usb_serial_port *port = tty->driver_data;
	struct ch341_private *priv = usb_get_serial_port_data(port);
	unsigned long flags;
	u8 control;

	spin_lock_irqsave(&priv->lock, flags);
	if (set & TIOCM_RTS)
		priv->mcr |= CH341_BIT_RTS;
	if (set & TIOCM_DTR)
		priv->mcr |= CH341_BIT_DTR;
	if (clear & TIOCM_RTS)
		priv->mcr &= ~CH341_BIT_RTS;
	if (clear & TIOCM_DTR)
		priv->mcr &= ~CH341_BIT_DTR;
	control = priv->mcr;
	spin_unlock_irqrestore(&priv->lock, flags);

	return ch341_set_handshake(port->serial->dev, control);
}

static void ch341_update_status(struct usb_serial_port *port,
					unsigned char *data, size_t len)
{
	struct ch341_private *priv = usb_get_serial_port_data(port);
	struct tty_struct *tty;
	unsigned long flags;
	u8 status;
	u8 delta;

	if (len < 4)
		return;

	status = ~data[2] & CH341_BITS_MODEM_STAT;

	spin_lock_irqsave(&priv->lock, flags);
	delta = status ^ priv->msr;
	priv->msr = status;
	spin_unlock_irqrestore(&priv->lock, flags);

	if (data[1] & CH341_MULT_STAT)
		dev_dbg(&port->dev, "%s - multiple status change\n", __func__);

	if (!delta)
		return;

	if (delta & CH341_BIT_CTS)
		port->icount.cts++;
	if (delta & CH341_BIT_DSR)
		port->icount.dsr++;
	if (delta & CH341_BIT_RI)
		port->icount.rng++;
	if (delta & CH341_BIT_DCD) {
		port->icount.dcd++;
		tty = tty_port_tty_get(&port->port);
		if (tty) {
			usb_serial_handle_dcd_change(port, tty,
						status & CH341_BIT_DCD);
			tty_kref_put(tty);
		}
	}

	wake_up_interruptible(&port->port.delta_msr_wait);
}

static void ch341_read_int_callback(struct urb *urb)
{
	struct usb_serial_port *port = urb->context;
	unsigned char *data = urb->transfer_buffer;
	unsigned int len = urb->actual_length;
	int status;

	switch (urb->status) {
	case 0:
		/* success */
		break;
	case -ECONNRESET:
	case -ENOENT:
	case -ESHUTDOWN:
		/* this urb is terminated, clean up */
		dev_dbg(&urb->dev->dev, "%s - urb shutting down: %d\n",
			__func__, urb->status);
		return;
	default:
		dev_dbg(&urb->dev->dev, "%s - nonzero urb status: %d\n",
			__func__, urb->status);
		goto exit;
	}

	usb_serial_debug_data(&port->dev, __func__, len, data);
	ch341_update_status(port, data, len);
exit:
	status = usb_submit_urb(urb, GFP_ATOMIC);
	if (status) {
		dev_err(&urb->dev->dev, "%s - usb_submit_urb failed: %d\n",
			__func__, status);
	}
}

static int ch341_tiocmget(struct tty_struct *tty)
{
	struct usb_serial_port *port = tty->driver_data;
	struct ch341_private *priv = usb_get_serial_port_data(port);
	unsigned long flags;
	u8 mcr;
	u8 status;
	unsigned int result;

	spin_lock_irqsave(&priv->lock, flags);
	mcr = priv->mcr;
	status = priv->msr;
	spin_unlock_irqrestore(&priv->lock, flags);

	result = ((mcr & CH341_BIT_DTR)		? TIOCM_DTR : 0)
		  | ((mcr & CH341_BIT_RTS)	? TIOCM_RTS : 0)
		  | ((status & CH341_BIT_CTS)	? TIOCM_CTS : 0)
		  | ((status & CH341_BIT_DSR)	? TIOCM_DSR : 0)
		  | ((status & CH341_BIT_RI)	? TIOCM_RI  : 0)
		  | ((status & CH341_BIT_DCD)	? TIOCM_CD  : 0);

	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);

	return result;
}

static int ch341_reset_resume(struct usb_serial *serial)
{
	struct usb_serial_port *port = serial->port[0];
	struct ch341_private *priv = usb_get_serial_port_data(port);
	int ret;

	/* reconfigure ch341 serial port after bus-reset */
	ch341_configure(serial->dev, priv);

	if (tty_port_initialized(&port->port)) {
		ret = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
		if (ret) {
			dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
				ret);
			return ret;
		}

		ret = ch341_get_status(port->serial->dev, priv);
		if (ret < 0) {
			dev_err(&port->dev, "failed to read modem status: %d\n",
				ret);
		}
	}

	return usb_serial_generic_resume(serial);
}

static struct usb_serial_driver ch341_device = {
	.driver = {
		.owner	= THIS_MODULE,
		.name	= "ch341-uart",
	},
	.id_table          = id_table,
	.num_ports         = 1,
	.open              = ch341_open,
	.dtr_rts	   = ch341_dtr_rts,
	.carrier_raised	   = ch341_carrier_raised,
	.close             = ch341_close,
	.set_termios       = ch341_set_termios,
	.break_ctl         = ch341_break_ctl,
	.tiocmget          = ch341_tiocmget,
	.tiocmset          = ch341_tiocmset,
	.tiocmiwait        = usb_serial_generic_tiocmiwait,
	.read_int_callback = ch341_read_int_callback,
	.port_probe        = ch341_port_probe,
	.port_remove       = ch341_port_remove,
	.reset_resume      = ch341_reset_resume,
};

static struct usb_serial_driver * const serial_drivers[] = {
	&ch341_device, NULL
};

module_usb_serial_driver(serial_drivers, id_table);

MODULE_LICENSE("GPL v2");
Commit	Line	Data
5fd54ace	1	// SPDX-License-Identifier: GPL-2.0
6ce76104 FK	2	/*
6ce76104 FK	3	* Copyright 2007, Frank A Kingswood <frank@kingswood-consulting.co.uk>
664d5df9 WC	4	* Copyright 2007, Werner Cornelius <werner@cornelius-consult.de>
664d5df9 WC	5	* Copyright 2009, Boris Hajduk <boris@hajduk.org>
6ce76104 FK	6	*
	7	* ch341.c implements a serial port driver for the Winchiphead CH341.
	8	*
	9	* The CH341 device can be used to implement an RS232 asynchronous
	10	* serial port, an IEEE-1284 parallel printer port or a memory-like
	11	* interface. In all cases the CH341 supports an I2C interface as well.
	12	* This driver only supports the asynchronous serial interface.
6ce76104 FK	13	*/
	14
	15	#include <linux/kernel.h>
6ce76104 FK	16	#include <linux/tty.h>
6ce76104 FK	17	#include <linux/module.h>
5a0e3ad6	18	#include <linux/slab.h>
6ce76104 FK	19	#include <linux/usb.h>
	20	#include <linux/usb/serial.h>
	21	#include <linux/serial.h>
5be796f0	22	#include <asm/unaligned.h>
6ce76104	23
664d5df9	24	#define DEFAULT_BAUD_RATE 9600
6ce76104 FK	25	#define DEFAULT_TIMEOUT 1000
6ce76104 FK	26
664d5df9 WC	27	/* flags for IO-Bits */
	28	#define CH341_BIT_RTS (1 << 6)
	29	#define CH341_BIT_DTR (1 << 5)
	30
	31	/******************************/
	32	/* interrupt pipe definitions */
	33	/******************************/
	34	/* always 4 interrupt bytes */
	35	/* first irq byte normally 0x08 */
	36	/* second irq byte base 0x7d + below */
	37	/* third irq byte base 0x94 + below */
	38	/* fourth irq byte normally 0xee */
	39
	40	/* second interrupt byte */
	41	#define CH341_MULT_STAT 0x04 /* multiple status since last interrupt event */
	42
	43	/* status returned in third interrupt answer byte, inverted in data
	44	from irq */
	45	#define CH341_BIT_CTS 0x01
	46	#define CH341_BIT_DSR 0x02
	47	#define CH341_BIT_RI 0x04
	48	#define CH341_BIT_DCD 0x08
	49	#define CH341_BITS_MODEM_STAT 0x0f /* all bits */
	50
	51	/*******************************/
	52	/* baudrate calculation factor */
	53	/*******************************/
	54	#define CH341_BAUDBASE_FACTOR 1532620800
	55	#define CH341_BAUDBASE_DIVMAX 3
	56
492896f0 TS	57	/* Break support - the information used to implement this was gleaned from
	58	* the Net/FreeBSD uchcom.c driver by Takanori Watanabe. Domo arigato.
	59	*/
	60
6fde8d29	61	#define CH341_REQ_READ_VERSION 0x5F
492896f0 TS	62	#define CH341_REQ_WRITE_REG 0x9A
492896f0 TS	63	#define CH341_REQ_READ_REG 0x95
6fde8d29 AT	64	#define CH341_REQ_SERIAL_INIT 0xA1
	65	#define CH341_REQ_MODEM_CTRL 0xA4
	66
	67	#define CH341_REG_BREAK 0x05
	68	#define CH341_REG_LCR 0x18
	69	#define CH341_NBREAK_BITS 0x01
	70
	71	#define CH341_LCR_ENABLE_RX 0x80
	72	#define CH341_LCR_ENABLE_TX 0x40
	73	#define CH341_LCR_MARK_SPACE 0x20
	74	#define CH341_LCR_PAR_EVEN 0x10
	75	#define CH341_LCR_ENABLE_PAR 0x08
	76	#define CH341_LCR_STOP_BITS_2 0x04
	77	#define CH341_LCR_CS8 0x03
	78	#define CH341_LCR_CS7 0x02
	79	#define CH341_LCR_CS6 0x01
	80	#define CH341_LCR_CS5 0x00
492896f0	81
7d40d7e8	82	static const struct usb_device_id id_table[] = {
6ce76104	83	{ USB_DEVICE(0x4348, 0x5523) },
82078234	84	{ USB_DEVICE(0x1a86, 0x7523) },
d0781383	85	{ USB_DEVICE(0x1a86, 0x5523) },
6ce76104 FK	86	{ },
	87	};
	88	MODULE_DEVICE_TABLE(usb, id_table);
	89
	90	struct ch341_private {
664d5df9	91	spinlock_t lock; /* access lock */
664d5df9	92	unsigned baud_rate; /* set baud rate */
beea33d4	93	u8 mcr;
e8024460	94	u8 msr;
3cca8624	95	u8 lcr;
6ce76104 FK	96	};
6ce76104 FK	97
aa91def4 NP	98	static void ch341_set_termios(struct tty_struct *tty,
	99	struct usb_serial_port *port,
	100	struct ktermios *old_termios);
	101
6ce76104 FK	102	static int ch341_control_out(struct usb_device *dev, u8 request,
	103	u16 value, u16 index)
	104	{
	105	int r;
79cbeeaf	106
91e0efcd JH	107	dev_dbg(&dev->dev, "%s - (%02x,%04x,%04x)\n", __func__,
91e0efcd JH	108	request, value, index);
6ce76104 FK	109
	110	r = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request,
	111	USB_TYPE_VENDOR \| USB_RECIP_DEVICE \| USB_DIR_OUT,
	112	value, index, NULL, 0, DEFAULT_TIMEOUT);
2d5a9c72 JH	113	if (r < 0)
2d5a9c72 JH	114	dev_err(&dev->dev, "failed to send control message: %d\n", r);
6ce76104 FK	115
	116	return r;
	117	}
	118
	119	static int ch341_control_in(struct usb_device *dev,
	120	u8 request, u16 value, u16 index,
	121	char *buf, unsigned bufsize)
	122	{
	123	int r;
79cbeeaf	124
91e0efcd JH	125	dev_dbg(&dev->dev, "%s - (%02x,%04x,%04x,%u)\n", __func__,
91e0efcd JH	126	request, value, index, bufsize);
6ce76104 FK	127
	128	r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request,
	129	USB_TYPE_VENDOR \| USB_RECIP_DEVICE \| USB_DIR_IN,
	130	value, index, buf, bufsize, DEFAULT_TIMEOUT);
e33eab9d	131	if (r < (int)bufsize) {
2d5a9c72 JH	132	if (r >= 0) {
	133	dev_err(&dev->dev,
	134	"short control message received (%d < %u)\n",
	135	r, bufsize);
	136	r = -EIO;
	137	}
	138
	139	dev_err(&dev->dev, "failed to receive control message: %d\n",
	140	r);
	141	return r;
	142	}
	143
	144	return 0;
6ce76104 FK	145	}
6ce76104 FK	146
55fa15b5 JH	147	static int ch341_set_baudrate_lcr(struct usb_device *dev,
55fa15b5 JH	148	struct ch341_private *priv, u8 lcr)
6ce76104	149	{
4e46c410	150	short a;
6ce76104	151	int r;
664d5df9 WC	152	unsigned long factor;
664d5df9 WC	153	short divisor;
6ce76104	154
664d5df9	155	if (!priv->baud_rate)
6ce76104	156	return -EINVAL;
664d5df9 WC	157	factor = (CH341_BAUDBASE_FACTOR / priv->baud_rate);
	158	divisor = CH341_BAUDBASE_DIVMAX;
	159
	160	while ((factor > 0xfff0) && divisor) {
	161	factor >>= 3;
	162	divisor--;
6ce76104 FK	163	}
6ce76104 FK	164
664d5df9 WC	165	if (factor > 0xfff0)
	166	return -EINVAL;
	167
	168	factor = 0x10000 - factor;
	169	a = (factor & 0xff00) \| divisor;
664d5df9	170
55fa15b5 JH	171	/*
	172	* CH341A buffers data until a full endpoint-size packet (32 bytes)
	173	* has been received unless bit 7 is set.
	174	*/
	175	a \|= BIT(7);
	176
	177	r = ch341_control_out(dev, CH341_REQ_WRITE_REG, 0x1312, a);
	178	if (r)
	179	return r;
	180
	181	r = ch341_control_out(dev, CH341_REQ_WRITE_REG, 0x2518, lcr);
	182	if (r)
	183	return r;
6ce76104 FK	184
	185	return r;
	186	}
	187
664d5df9	188	static int ch341_set_handshake(struct usb_device *dev, u8 control)
6ce76104	189	{
6fde8d29	190	return ch341_control_out(dev, CH341_REQ_MODEM_CTRL, ~control, 0);
6ce76104 FK	191	}
6ce76104 FK	192
664d5df9	193	static int ch341_get_status(struct usb_device dev, struct ch341_private priv)
6ce76104	194	{
2d5a9c72	195	const unsigned int size = 2;
6ce76104 FK	196	char *buffer;
6ce76104 FK	197	int r;
664d5df9	198	unsigned long flags;
6ce76104	199
6ce76104 FK	200	buffer = kmalloc(size, GFP_KERNEL);
	201	if (!buffer)
	202	return -ENOMEM;
	203
6fde8d29	204	r = ch341_control_in(dev, CH341_REQ_READ_REG, 0x0706, 0, buffer, size);
c4d0f8cb	205	if (r < 0)
6ce76104 FK	206	goto out;
6ce76104 FK	207
2d5a9c72	208	spin_lock_irqsave(&priv->lock, flags);
e8024460	209	priv->msr = (~(*buffer)) & CH341_BITS_MODEM_STAT;
2d5a9c72	210	spin_unlock_irqrestore(&priv->lock, flags);
6ce76104 FK	211
	212	out: kfree(buffer);
	213	return r;
	214	}
	215
	216	/* -------------------------------------------------------------------------- */
	217
93b6497d	218	static int ch341_configure(struct usb_device dev, struct ch341_private priv)
6ce76104	219	{
2d5a9c72	220	const unsigned int size = 2;
6ce76104 FK	221	char *buffer;
6ce76104 FK	222	int r;
6ce76104	223
6ce76104 FK	224	buffer = kmalloc(size, GFP_KERNEL);
	225	if (!buffer)
	226	return -ENOMEM;
	227
	228	/* expect two bytes 0x27 0x00 */
6fde8d29	229	r = ch341_control_in(dev, CH341_REQ_READ_VERSION, 0, 0, buffer, size);
6ce76104 FK	230	if (r < 0)
6ce76104 FK	231	goto out;
a98b6900	232	dev_dbg(&dev->dev, "Chip version: 0x%02x\n", buffer[0]);
6ce76104	233
6fde8d29	234	r = ch341_control_out(dev, CH341_REQ_SERIAL_INIT, 0, 0);
6ce76104 FK	235	if (r < 0)
	236	goto out;
	237
55fa15b5	238	r = ch341_set_baudrate_lcr(dev, priv, priv->lcr);
6ce76104 FK	239	if (r < 0)
	240	goto out;
	241
beea33d4	242	r = ch341_set_handshake(dev, priv->mcr);
6ce76104 FK	243
	244	out: kfree(buffer);
	245	return r;
	246	}
	247
456c5be5	248	static int ch341_port_probe(struct usb_serial_port *port)
6ce76104 FK	249	{
	250	struct ch341_private *priv;
	251	int r;
	252
6ce76104 FK	253	priv = kzalloc(sizeof(struct ch341_private), GFP_KERNEL);
	254	if (!priv)
	255	return -ENOMEM;
	256
664d5df9	257	spin_lock_init(&priv->lock);
6ce76104	258	priv->baud_rate = DEFAULT_BAUD_RATE;
7c61b0d5 JH	259	/*
	260	* Some CH340 devices appear unable to change the initial LCR
	261	* settings, so set a sane 8N1 default.
	262	*/
	263	priv->lcr = CH341_LCR_ENABLE_RX \| CH341_LCR_ENABLE_TX \| CH341_LCR_CS8;
6ce76104	264
456c5be5	265	r = ch341_configure(port->serial->dev, priv);
6ce76104 FK	266	if (r < 0)
	267	goto error;
	268
456c5be5	269	usb_set_serial_port_data(port, priv);
6ce76104 FK	270	return 0;
	271
	272	error: kfree(priv);
	273	return r;
	274	}
	275
456c5be5 JH	276	static int ch341_port_remove(struct usb_serial_port *port)
	277	{
	278	struct ch341_private *priv;
	279
	280	priv = usb_get_serial_port_data(port);
	281	kfree(priv);
	282
	283	return 0;
	284	}
	285
335f8514 AC	286	static int ch341_carrier_raised(struct usb_serial_port *port)
	287	{
	288	struct ch341_private *priv = usb_get_serial_port_data(port);
e8024460	289	if (priv->msr & CH341_BIT_DCD)
335f8514 AC	290	return 1;
	291	return 0;
	292	}
	293
	294	static void ch341_dtr_rts(struct usb_serial_port *port, int on)
664d5df9 WC	295	{
	296	struct ch341_private *priv = usb_get_serial_port_data(port);
	297	unsigned long flags;
664d5df9	298
335f8514 AC	299	/* drop DTR and RTS */
	300	spin_lock_irqsave(&priv->lock, flags);
	301	if (on)
beea33d4	302	priv->mcr \|= CH341_BIT_RTS \| CH341_BIT_DTR;
335f8514	303	else
beea33d4	304	priv->mcr &= ~(CH341_BIT_RTS \| CH341_BIT_DTR);
335f8514	305	spin_unlock_irqrestore(&priv->lock, flags);
beea33d4	306	ch341_set_handshake(port->serial->dev, priv->mcr);
335f8514 AC	307	}
	308
	309	static void ch341_close(struct usb_serial_port *port)
	310	{
f26788da	311	usb_serial_generic_close(port);
664d5df9	312	usb_kill_urb(port->interrupt_in_urb);
664d5df9 WC	313	}
	314
	315
6ce76104	316	/* open this device, set default parameters */
a509a7e4	317	static int ch341_open(struct tty_struct tty, struct usb_serial_port port)
6ce76104	318	{
456c5be5	319	struct ch341_private *priv = usb_get_serial_port_data(port);
6ce76104 FK	320	int r;
6ce76104 FK	321
aa91def4 NP	322	if (tty)
aa91def4 NP	323	ch341_set_termios(tty, port, NULL);
6ce76104	324
d9a38a87	325	dev_dbg(&port->dev, "%s - submitting interrupt urb\n", __func__);
664d5df9 WC	326	r = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
664d5df9 WC	327	if (r) {
d9a38a87 JH	328	dev_err(&port->dev, "%s - failed to submit interrupt urb: %d\n",
d9a38a87 JH	329	__func__, r);
f2950b78	330	return r;
664d5df9 WC	331	}
664d5df9 WC	332
a0467a96 JH	333	r = ch341_get_status(port->serial->dev, priv);
	334	if (r < 0) {
	335	dev_err(&port->dev, "failed to read modem status: %d\n", r);
	336	goto err_kill_interrupt_urb;
	337	}
	338
a509a7e4	339	r = usb_serial_generic_open(tty, port);
f2950b78 JH	340	if (r)
	341	goto err_kill_interrupt_urb;
	342
	343	return 0;
	344
	345	err_kill_interrupt_urb:
	346	usb_kill_urb(port->interrupt_in_urb);
6ce76104	347
f2950b78	348	return r;
6ce76104 FK	349	}
	350
	351	/* Old_termios contains the original termios settings and
	352	* tty->termios contains the new setting to be used.
	353	*/
95da310e AC	354	static void ch341_set_termios(struct tty_struct *tty,
95da310e AC	355	struct usb_serial_port port, struct ktermios old_termios)
6ce76104 FK	356	{
6ce76104 FK	357	struct ch341_private *priv = usb_get_serial_port_data(port);
6ce76104	358	unsigned baud_rate;
664d5df9	359	unsigned long flags;
448b6dc5	360	u8 lcr;
4e46c410 AT	361	int r;
	362
	363	/* redundant changes may cause the chip to lose bytes */
	364	if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
	365	return;
6ce76104	366
6ce76104 FK	367	baud_rate = tty_get_baud_rate(tty);
6ce76104 FK	368
448b6dc5	369	lcr = CH341_LCR_ENABLE_RX \| CH341_LCR_ENABLE_TX;
ba781bdf AT	370
	371	switch (C_CSIZE(tty)) {
	372	case CS5:
448b6dc5	373	lcr \|= CH341_LCR_CS5;
ba781bdf AT	374	break;
ba781bdf AT	375	case CS6:
448b6dc5	376	lcr \|= CH341_LCR_CS6;
ba781bdf AT	377	break;
ba781bdf AT	378	case CS7:
448b6dc5	379	lcr \|= CH341_LCR_CS7;
ba781bdf AT	380	break;
ba781bdf AT	381	case CS8:
448b6dc5	382	lcr \|= CH341_LCR_CS8;
ba781bdf AT	383	break;
	384	}
	385
	386	if (C_PARENB(tty)) {
448b6dc5	387	lcr \|= CH341_LCR_ENABLE_PAR;
ba781bdf	388	if (C_PARODD(tty) == 0)
448b6dc5	389	lcr \|= CH341_LCR_PAR_EVEN;
ba781bdf	390	if (C_CMSPAR(tty))
448b6dc5	391	lcr \|= CH341_LCR_MARK_SPACE;
ba781bdf	392	}
664d5df9	393
ba781bdf	394	if (C_CSTOPB(tty))
448b6dc5	395	lcr \|= CH341_LCR_STOP_BITS_2;
4e46c410	396
664d5df9	397	if (baud_rate) {
a20047f3 JH	398	priv->baud_rate = baud_rate;
a20047f3 JH	399
448b6dc5	400	r = ch341_set_baudrate_lcr(port->serial->dev, priv, lcr);
4e46c410 AT	401	if (r < 0 && old_termios) {
	402	priv->baud_rate = tty_termios_baud_rate(old_termios);
	403	tty_termios_copy_hw(&tty->termios, old_termios);
3cca8624	404	} else if (r == 0) {
448b6dc5	405	priv->lcr = lcr;
4e46c410	406	}
6ce76104 FK	407	}
6ce76104 FK	408
030ee7ae JH	409	spin_lock_irqsave(&priv->lock, flags);
030ee7ae JH	410	if (C_BAUD(tty) == B0)
beea33d4	411	priv->mcr &= ~(CH341_BIT_DTR \| CH341_BIT_RTS);
030ee7ae	412	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
beea33d4	413	priv->mcr \|= (CH341_BIT_DTR \| CH341_BIT_RTS);
030ee7ae	414	spin_unlock_irqrestore(&priv->lock, flags);
6ce76104	415
beea33d4	416	ch341_set_handshake(port->serial->dev, priv->mcr);
664d5df9 WC	417	}
664d5df9 WC	418
492896f0 TS	419	static void ch341_break_ctl(struct tty_struct *tty, int break_state)
	420	{
	421	const uint16_t ch341_break_reg =
6fde8d29	422	((uint16_t) CH341_REG_LCR << 8) \| CH341_REG_BREAK;
492896f0 TS	423	struct usb_serial_port *port = tty->driver_data;
	424	int r;
	425	uint16_t reg_contents;
f2b5cc83	426	uint8_t *break_reg;
492896f0	427
f2b5cc83	428	break_reg = kmalloc(2, GFP_KERNEL);
10c642d0	429	if (!break_reg)
f2b5cc83	430	return;
f2b5cc83	431
492896f0	432	r = ch341_control_in(port->serial->dev, CH341_REQ_READ_REG,
f2b5cc83	433	ch341_break_reg, 0, break_reg, 2);
492896f0	434	if (r < 0) {
6a9b15fe JH	435	dev_err(&port->dev, "%s - USB control read error (%d)\n",
6a9b15fe JH	436	__func__, r);
f2b5cc83	437	goto out;
492896f0	438	}
79cbeeaf GKH	439	dev_dbg(&port->dev, "%s - initial ch341 break register contents - reg1: %x, reg2: %x\n",
79cbeeaf GKH	440	__func__, break_reg[0], break_reg[1]);
492896f0	441	if (break_state != 0) {
79cbeeaf	442	dev_dbg(&port->dev, "%s - Enter break state requested\n", __func__);
6fde8d29 AT	443	break_reg[0] &= ~CH341_NBREAK_BITS;
6fde8d29 AT	444	break_reg[1] &= ~CH341_LCR_ENABLE_TX;
492896f0	445	} else {
79cbeeaf	446	dev_dbg(&port->dev, "%s - Leave break state requested\n", __func__);
6fde8d29 AT	447	break_reg[0] \|= CH341_NBREAK_BITS;
6fde8d29 AT	448	break_reg[1] \|= CH341_LCR_ENABLE_TX;
492896f0	449	}
79cbeeaf GKH	450	dev_dbg(&port->dev, "%s - New ch341 break register contents - reg1: %x, reg2: %x\n",
79cbeeaf GKH	451	__func__, break_reg[0], break_reg[1]);
5be796f0	452	reg_contents = get_unaligned_le16(break_reg);
492896f0 TS	453	r = ch341_control_out(port->serial->dev, CH341_REQ_WRITE_REG,
	454	ch341_break_reg, reg_contents);
	455	if (r < 0)
6a9b15fe JH	456	dev_err(&port->dev, "%s - USB control write error (%d)\n",
6a9b15fe JH	457	__func__, r);
f2b5cc83 JH	458	out:
f2b5cc83 JH	459	kfree(break_reg);
492896f0 TS	460	}
492896f0 TS	461
20b9d177	462	static int ch341_tiocmset(struct tty_struct *tty,
664d5df9 WC	463	unsigned int set, unsigned int clear)
	464	{
	465	struct usb_serial_port *port = tty->driver_data;
	466	struct ch341_private *priv = usb_get_serial_port_data(port);
	467	unsigned long flags;
	468	u8 control;
	469
	470	spin_lock_irqsave(&priv->lock, flags);
	471	if (set & TIOCM_RTS)
beea33d4	472	priv->mcr \|= CH341_BIT_RTS;
664d5df9	473	if (set & TIOCM_DTR)
beea33d4	474	priv->mcr \|= CH341_BIT_DTR;
664d5df9	475	if (clear & TIOCM_RTS)
beea33d4	476	priv->mcr &= ~CH341_BIT_RTS;
664d5df9	477	if (clear & TIOCM_DTR)
beea33d4 JH	478	priv->mcr &= ~CH341_BIT_DTR;
beea33d4 JH	479	control = priv->mcr;
664d5df9 WC	480	spin_unlock_irqrestore(&priv->lock, flags);
	481
	482	return ch341_set_handshake(port->serial->dev, control);
	483	}
	484
e8024460	485	static void ch341_update_status(struct usb_serial_port *port,
ac035628 JH	486	unsigned char *data, size_t len)
	487	{
	488	struct ch341_private *priv = usb_get_serial_port_data(port);
b770081f	489	struct tty_struct *tty;
ac035628	490	unsigned long flags;
b770081f JH	491	u8 status;
b770081f JH	492	u8 delta;
ac035628 JH	493
	494	if (len < 4)
	495	return;
	496
b770081f JH	497	status = ~data[2] & CH341_BITS_MODEM_STAT;
b770081f JH	498
ac035628	499	spin_lock_irqsave(&priv->lock, flags);
e8024460 JH	500	delta = status ^ priv->msr;
e8024460 JH	501	priv->msr = status;
ac035628 JH	502	spin_unlock_irqrestore(&priv->lock, flags);
ac035628 JH	503
fd74b0b1 JH	504	if (data[1] & CH341_MULT_STAT)
	505	dev_dbg(&port->dev, "%s - multiple status change\n", __func__);
	506
d984fe91 JH	507	if (!delta)
	508	return;
	509
5e409a26 JH	510	if (delta & CH341_BIT_CTS)
	511	port->icount.cts++;
	512	if (delta & CH341_BIT_DSR)
	513	port->icount.dsr++;
	514	if (delta & CH341_BIT_RI)
	515	port->icount.rng++;
b770081f	516	if (delta & CH341_BIT_DCD) {
5e409a26	517	port->icount.dcd++;
b770081f JH	518	tty = tty_port_tty_get(&port->port);
b770081f JH	519	if (tty) {
ac035628	520	usb_serial_handle_dcd_change(port, tty,
b770081f JH	521	status & CH341_BIT_DCD);
	522	tty_kref_put(tty);
	523	}
ac035628 JH	524	}
	525
	526	wake_up_interruptible(&port->port.delta_msr_wait);
	527	}
	528
664d5df9 WC	529	static void ch341_read_int_callback(struct urb *urb)
664d5df9 WC	530	{
271ec2d2	531	struct usb_serial_port *port = urb->context;
664d5df9	532	unsigned char *data = urb->transfer_buffer;
271ec2d2	533	unsigned int len = urb->actual_length;
664d5df9 WC	534	int status;
664d5df9 WC	535
664d5df9 WC	536	switch (urb->status) {
	537	case 0:
	538	/* success */
	539	break;
	540	case -ECONNRESET:
	541	case -ENOENT:
	542	case -ESHUTDOWN:
	543	/* this urb is terminated, clean up */
271ec2d2	544	dev_dbg(&urb->dev->dev, "%s - urb shutting down: %d\n",
79cbeeaf	545	__func__, urb->status);
664d5df9 WC	546	return;
664d5df9 WC	547	default:
271ec2d2	548	dev_dbg(&urb->dev->dev, "%s - nonzero urb status: %d\n",
79cbeeaf	549	__func__, urb->status);
664d5df9 WC	550	goto exit;
	551	}
	552
271ec2d2	553	usb_serial_debug_data(&port->dev, __func__, len, data);
e8024460	554	ch341_update_status(port, data, len);
664d5df9 WC	555	exit:
664d5df9 WC	556	status = usb_submit_urb(urb, GFP_ATOMIC);
271ec2d2 JH	557	if (status) {
271ec2d2 JH	558	dev_err(&urb->dev->dev, "%s - usb_submit_urb failed: %d\n",
664d5df9	559	__func__, status);
271ec2d2	560	}
664d5df9 WC	561	}
664d5df9 WC	562
60b33c13	563	static int ch341_tiocmget(struct tty_struct *tty)
664d5df9 WC	564	{
	565	struct usb_serial_port *port = tty->driver_data;
	566	struct ch341_private *priv = usb_get_serial_port_data(port);
	567	unsigned long flags;
	568	u8 mcr;
	569	u8 status;
	570	unsigned int result;
	571
664d5df9	572	spin_lock_irqsave(&priv->lock, flags);
beea33d4	573	mcr = priv->mcr;
e8024460	574	status = priv->msr;
664d5df9 WC	575	spin_unlock_irqrestore(&priv->lock, flags);
	576
	577	result = ((mcr & CH341_BIT_DTR) ? TIOCM_DTR : 0)
	578	\| ((mcr & CH341_BIT_RTS) ? TIOCM_RTS : 0)
	579	\| ((status & CH341_BIT_CTS) ? TIOCM_CTS : 0)
	580	\| ((status & CH341_BIT_DSR) ? TIOCM_DSR : 0)
	581	\| ((status & CH341_BIT_RI) ? TIOCM_RI : 0)
	582	\| ((status & CH341_BIT_DCD) ? TIOCM_CD : 0);
	583
79cbeeaf	584	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
73f59308	585
664d5df9	586	return result;
6ce76104 FK	587	}
6ce76104 FK	588
622b80cf	589	static int ch341_reset_resume(struct usb_serial *serial)
1ded7ea4	590	{
ce5e2928 JH	591	struct usb_serial_port *port = serial->port[0];
	592	struct ch341_private *priv = usb_get_serial_port_data(port);
	593	int ret;
1ded7ea4	594
2bfd1c96 GKH	595	/* reconfigure ch341 serial port after bus-reset */
2bfd1c96 GKH	596	ch341_configure(serial->dev, priv);
1ded7ea4	597
ce5e2928 JH	598	if (tty_port_initialized(&port->port)) {
	599	ret = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
	600	if (ret) {
	601	dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
	602	ret);
	603	return ret;
	604	}
a0467a96 JH	605
	606	ret = ch341_get_status(port->serial->dev, priv);
	607	if (ret < 0) {
	608	dev_err(&port->dev, "failed to read modem status: %d\n",
	609	ret);
	610	}
ce5e2928 JH	611	}
	612
	613	return usb_serial_generic_resume(serial);
1ded7ea4 ML	614	}
1ded7ea4 ML	615
6ce76104 FK	616	static struct usb_serial_driver ch341_device = {
	617	.driver = {
	618	.owner = THIS_MODULE,
	619	.name = "ch341-uart",
	620	},
664d5df9	621	.id_table = id_table,
664d5df9 WC	622	.num_ports = 1,
664d5df9 WC	623	.open = ch341_open,
335f8514 AC	624	.dtr_rts = ch341_dtr_rts,
335f8514 AC	625	.carrier_raised = ch341_carrier_raised,
664d5df9	626	.close = ch341_close,
664d5df9	627	.set_termios = ch341_set_termios,
492896f0	628	.break_ctl = ch341_break_ctl,
664d5df9 WC	629	.tiocmget = ch341_tiocmget,
664d5df9 WC	630	.tiocmset = ch341_tiocmset,
5e409a26	631	.tiocmiwait = usb_serial_generic_tiocmiwait,
664d5df9	632	.read_int_callback = ch341_read_int_callback,
456c5be5 JH	633	.port_probe = ch341_port_probe,
456c5be5 JH	634	.port_remove = ch341_port_remove,
1c1eaba8	635	.reset_resume = ch341_reset_resume,
6ce76104 FK	636	};
6ce76104 FK	637
08a4f6bc AS	638	static struct usb_serial_driver * const serial_drivers[] = {
	639	&ch341_device, NULL
	640	};
	641
68e24113	642	module_usb_serial_driver(serial_drivers, id_table);
6ce76104	643
627cfa89	644	MODULE_LICENSE("GPL v2");