[deliverable/linux.git] / drivers / usb / serial / ch341.c

/*
 * 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.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 as published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/tty.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <linux/serial.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_WRITE_REG    0x9A
#define CH341_REQ_READ_REG     0x95
#define CH341_REG_BREAK1       0x05
#define CH341_REG_BREAK2       0x18
#define CH341_NBREAK_BITS_REG1 0x01
#define CH341_NBREAK_BITS_REG2 0x40


static int debug;

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

struct ch341_private {
	spinlock_t lock; /* access lock */
	wait_queue_head_t delta_msr_wait; /* wait queue for modem status */
	unsigned baud_rate; /* set baud rate */
	u8 line_control; /* set line control value RTS/DTR */
	u8 line_status; /* active status of modem control inputs */
	u8 multi_status_change; /* status changed multiple since last call */
};

static int ch341_control_out(struct usb_device *dev, u8 request,
			     u16 value, u16 index)
{
	int r;
	dbg("ch341_control_out(%02x,%02x,%04x,%04x)", USB_DIR_OUT|0x40,
		(int)request, (int)value, (int)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);

	return r;
}

static int ch341_control_in(struct usb_device *dev,
			    u8 request, u16 value, u16 index,
			    char *buf, unsigned bufsize)
{
	int r;
	dbg("ch341_control_in(%02x,%02x,%04x,%04x,%p,%u)", USB_DIR_IN|0x40,
		(int)request, (int)value, (int)index, buf, (int)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);
	return r;
}

static int ch341_set_baudrate(struct usb_device *dev,
			      struct ch341_private *priv)
{
	short a, b;
	int r;
	unsigned long factor;
	short divisor;

	dbg("ch341_set_baudrate(%d)", priv->baud_rate);

	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;
	b = factor & 0xff;

	r = ch341_control_out(dev, 0x9a, 0x1312, a);
	if (!r)
		r = ch341_control_out(dev, 0x9a, 0x0f2c, b);

	return r;
}

static int ch341_set_handshake(struct usb_device *dev, u8 control)
{
	dbg("ch341_set_handshake(0x%02x)", control);
	return ch341_control_out(dev, 0xa4, ~control, 0);
}

static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
{
	char *buffer;
	int r;
	const unsigned size = 8;
	unsigned long flags;

	dbg("ch341_get_status()");

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

	r = ch341_control_in(dev, 0x95, 0x0706, 0, buffer, size);
	if (r < 0)
		goto out;

	/* setup the private status if available */
	if (r == 2) {
		r = 0;
		spin_lock_irqsave(&priv->lock, flags);
		priv->line_status = (~(*buffer)) & CH341_BITS_MODEM_STAT;
		priv->multi_status_change = 0;
		spin_unlock_irqrestore(&priv->lock, flags);
	} else
		r = -EPROTO;

out:	kfree(buffer);
	return r;
}

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

static int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
{
	char *buffer;
	int r;
	const unsigned size = 8;

	dbg("ch341_configure()");

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

	/* expect two bytes 0x27 0x00 */
	r = ch341_control_in(dev, 0x5f, 0, 0, buffer, size);
	if (r < 0)
		goto out;

	r = ch341_control_out(dev, 0xa1, 0, 0);
	if (r < 0)
		goto out;

	r = ch341_set_baudrate(dev, priv);
	if (r < 0)
		goto out;

	/* expect two bytes 0x56 0x00 */
	r = ch341_control_in(dev, 0x95, 0x2518, 0, buffer, size);
	if (r < 0)
		goto out;

	r = ch341_control_out(dev, 0x9a, 0x2518, 0x0050);
	if (r < 0)
		goto out;

	/* expect 0xff 0xee */
	r = ch341_get_status(dev, priv);
	if (r < 0)
		goto out;

	r = ch341_control_out(dev, 0xa1, 0x501f, 0xd90a);
	if (r < 0)
		goto out;

	r = ch341_set_baudrate(dev, priv);
	if (r < 0)
		goto out;

	r = ch341_set_handshake(dev, priv->line_control);
	if (r < 0)
		goto out;

	/* expect 0x9f 0xee */
	r = ch341_get_status(dev, priv);

out:	kfree(buffer);
	return r;
}

/* allocate private data */
static int ch341_attach(struct usb_serial *serial)
{
	struct ch341_private *priv;
	int r;

	dbg("ch341_attach()");

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

	spin_lock_init(&priv->lock);
	init_waitqueue_head(&priv->delta_msr_wait);
	priv->baud_rate = DEFAULT_BAUD_RATE;
	priv->line_control = CH341_BIT_RTS | CH341_BIT_DTR;

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

	usb_set_serial_port_data(serial->port[0], priv);
	return 0;

error:	kfree(priv);
	return r;
}

static int ch341_carrier_raised(struct usb_serial_port *port)
{
	struct ch341_private *priv = usb_get_serial_port_data(port);
	if (priv->line_status & 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;

	dbg("%s - port %d", __func__, port->number);
	/* drop DTR and RTS */
	spin_lock_irqsave(&priv->lock, flags);
	if (on)
		priv->line_control |= CH341_BIT_RTS | CH341_BIT_DTR;
	else
		priv->line_control &= ~(CH341_BIT_RTS | CH341_BIT_DTR);
	spin_unlock_irqrestore(&priv->lock, flags);
	ch341_set_handshake(port->serial->dev, priv->line_control);
	wake_up_interruptible(&priv->delta_msr_wait);
}

static void ch341_close(struct usb_serial_port *port)
{
	dbg("%s - port %d", __func__, port->number);

	/* shutdown our urbs */
	dbg("%s - shutting down urbs", __func__);
	usb_kill_urb(port->write_urb);
	usb_kill_urb(port->read_urb);
	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 usb_serial *serial = port->serial;
	struct ch341_private *priv = usb_get_serial_port_data(serial->port[0]);
	int r;

	dbg("ch341_open()");

	priv->baud_rate = DEFAULT_BAUD_RATE;

	r = ch341_configure(serial->dev, priv);
	if (r)
		goto out;

	r = ch341_set_handshake(serial->dev, priv->line_control);
	if (r)
		goto out;

	r = ch341_set_baudrate(serial->dev, priv);
	if (r)
		goto out;

	dbg("%s - submitting interrupt urb", __func__);
	port->interrupt_in_urb->dev = serial->dev;
	r = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
	if (r) {
		dev_err(&port->dev, "%s - failed submitting interrupt urb,"
			" error %d\n", __func__, r);
		ch341_close(port);
		return -EPROTO;
	}

	r = usb_serial_generic_open(tty, port);

out:	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;

	dbg("ch341_set_termios()");

	baud_rate = tty_get_baud_rate(tty);

	priv->baud_rate = baud_rate;

	if (baud_rate) {
		spin_lock_irqsave(&priv->lock, flags);
		priv->line_control |= (CH341_BIT_DTR | CH341_BIT_RTS);
		spin_unlock_irqrestore(&priv->lock, flags);
		ch341_set_baudrate(port->serial->dev, priv);
	} else {
		spin_lock_irqsave(&priv->lock, flags);
		priv->line_control &= ~(CH341_BIT_DTR | CH341_BIT_RTS);
		spin_unlock_irqrestore(&priv->lock, flags);
	}

	ch341_set_handshake(port->serial->dev, priv->line_control);

	/* Unimplemented:
	 * (cflag & CSIZE) : data bits [5, 8]
	 * (cflag & PARENB) : parity {NONE, EVEN, ODD}
	 * (cflag & CSTOPB) : stop bits [1, 2]
	 */
}

static void ch341_break_ctl(struct tty_struct *tty, int break_state)
{
	const uint16_t ch341_break_reg =
		CH341_REG_BREAK1 | ((uint16_t) CH341_REG_BREAK2 << 8);
	struct usb_serial_port *port = tty->driver_data;
	int r;
	uint16_t reg_contents;
	uint8_t break_reg[2];

	dbg("%s()", __func__);

	r = ch341_control_in(port->serial->dev, CH341_REQ_READ_REG,
			ch341_break_reg, 0, break_reg, sizeof(break_reg));
	if (r < 0) {
		printk(KERN_WARNING "%s: USB control read error whilst getting"
				" break register contents.\n", __FILE__);
		return;
	}
	dbg("%s - initial ch341 break register contents - reg1: %x, reg2: %x",
			__func__, break_reg[0], break_reg[1]);
	if (break_state != 0) {
		dbg("%s - Enter break state requested", __func__);
		break_reg[0] &= ~CH341_NBREAK_BITS_REG1;
		break_reg[1] &= ~CH341_NBREAK_BITS_REG2;
	} else {
		dbg("%s - Leave break state requested", __func__);
		break_reg[0] |= CH341_NBREAK_BITS_REG1;
		break_reg[1] |= CH341_NBREAK_BITS_REG2;
	}
	dbg("%s - New ch341 break register contents - reg1: %x, reg2: %x",
			__func__, break_reg[0], break_reg[1]);
	reg_contents = (uint16_t)break_reg[0] | ((uint16_t)break_reg[1] << 8);
	r = ch341_control_out(port->serial->dev, CH341_REQ_WRITE_REG,
			ch341_break_reg, reg_contents);
	if (r < 0)
		printk(KERN_WARNING "%s: USB control write error whilst setting"
				" break register contents.\n", __FILE__);
}

static int ch341_tiocmset(struct tty_struct *tty, struct file *file,
			  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->line_control |= CH341_BIT_RTS;
	if (set & TIOCM_DTR)
		priv->line_control |= CH341_BIT_DTR;
	if (clear & TIOCM_RTS)
		priv->line_control &= ~CH341_BIT_RTS;
	if (clear & TIOCM_DTR)
		priv->line_control &= ~CH341_BIT_DTR;
	control = priv->line_control;
	spin_unlock_irqrestore(&priv->lock, flags);

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

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

	dbg("%s (%d)", __func__, port->number);

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

	usb_serial_debug_data(debug, &port->dev, __func__,
			      urb->actual_length, urb->transfer_buffer);

	if (actual_length >= 4) {
		struct ch341_private *priv = usb_get_serial_port_data(port);
		unsigned long flags;

		spin_lock_irqsave(&priv->lock, flags);
		priv->line_status = (~(data[2])) & CH341_BITS_MODEM_STAT;
		if ((data[1] & CH341_MULT_STAT))
			priv->multi_status_change = 1;
		spin_unlock_irqrestore(&priv->lock, flags);
		wake_up_interruptible(&priv->delta_msr_wait);
	}

exit:
	status = usb_submit_urb(urb, GFP_ATOMIC);
	if (status)
		dev_err(&urb->dev->dev,
			"%s - usb_submit_urb failed with result %d\n",
			__func__, status);
}

static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
{
	struct ch341_private *priv = usb_get_serial_port_data(port);
	unsigned long flags;
	u8 prevstatus;
	u8 status;
	u8 changed;
	u8 multi_change = 0;

	spin_lock_irqsave(&priv->lock, flags);
	prevstatus = priv->line_status;
	priv->multi_status_change = 0;
	spin_unlock_irqrestore(&priv->lock, flags);

	while (!multi_change) {
		interruptible_sleep_on(&priv->delta_msr_wait);
		/* see if a signal did it */
		if (signal_pending(current))
			return -ERESTARTSYS;

		spin_lock_irqsave(&priv->lock, flags);
		status = priv->line_status;
		multi_change = priv->multi_status_change;
		spin_unlock_irqrestore(&priv->lock, flags);

		changed = prevstatus ^ status;

		if (((arg & TIOCM_RNG) && (changed & CH341_BIT_RI)) ||
		    ((arg & TIOCM_DSR) && (changed & CH341_BIT_DSR)) ||
		    ((arg & TIOCM_CD)  && (changed & CH341_BIT_DCD)) ||
		    ((arg & TIOCM_CTS) && (changed & CH341_BIT_CTS))) {
			return 0;
		}
		prevstatus = status;
	}

	return 0;
}

/*static int ch341_ioctl(struct usb_serial_port *port, struct file *file,*/
static int ch341_ioctl(struct tty_struct *tty, struct file *file,
			unsigned int cmd, unsigned long arg)
{
	struct usb_serial_port *port = tty->driver_data;
	dbg("%s (%d) cmd = 0x%04x", __func__, port->number, cmd);

	switch (cmd) {
	case TIOCMIWAIT:
		dbg("%s (%d) TIOCMIWAIT", __func__,  port->number);
		return wait_modem_info(port, arg);

	default:
		dbg("%s not supported = 0x%04x", __func__, cmd);
		break;
	}

	return -ENOIOCTLCMD;
}

static int ch341_tiocmget(struct tty_struct *tty, struct file *file)
{
	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;

	dbg("%s (%d)", __func__, port->number);

	spin_lock_irqsave(&priv->lock, flags);
	mcr = priv->line_control;
	status = priv->line_status;
	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);

	dbg("%s - result = %x", __func__, result);

	return result;
}


static int ch341_reset_resume(struct usb_interface *intf)
{
	struct usb_device *dev = interface_to_usbdev(intf);
	struct usb_serial *serial = NULL;
	struct ch341_private *priv;

	serial = usb_get_intfdata(intf);
	priv = usb_get_serial_port_data(serial->port[0]);

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

	usb_serial_resume(intf);

	return 0;
}

static struct usb_driver ch341_driver = {
	.name		= "ch341",
	.probe		= usb_serial_probe,
	.disconnect	= usb_serial_disconnect,
	.suspend	= usb_serial_suspend,
	.resume		= usb_serial_resume,
	.reset_resume	= ch341_reset_resume,
	.id_table	= id_table,
	.no_dynamic_id	= 1,
	.supports_autosuspend =	1,
};

static struct usb_serial_driver ch341_device = {
	.driver = {
		.owner	= THIS_MODULE,
		.name	= "ch341-uart",
	},
	.id_table          = id_table,
	.usb_driver        = &ch341_driver,
	.num_ports         = 1,
	.open              = ch341_open,
	.dtr_rts	   = ch341_dtr_rts,
	.carrier_raised	   = ch341_carrier_raised,
	.close             = ch341_close,
	.ioctl             = ch341_ioctl,
	.set_termios       = ch341_set_termios,
	.break_ctl         = ch341_break_ctl,
	.tiocmget          = ch341_tiocmget,
	.tiocmset          = ch341_tiocmset,
	.read_int_callback = ch341_read_int_callback,
	.attach            = ch341_attach,
};

static int __init ch341_init(void)
{
	int retval;

	retval = usb_serial_register(&ch341_device);
	if (retval)
		return retval;
	retval = usb_register(&ch341_driver);
	if (retval)
		usb_serial_deregister(&ch341_device);
	return retval;
}

static void __exit ch341_exit(void)
{
	usb_deregister(&ch341_driver);
	usb_serial_deregister(&ch341_device);
}

module_init(ch341_init);
module_exit(ch341_exit);
MODULE_LICENSE("GPL");

module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug enabled or not");

/* EOF ch341.c */
Commit	Line	Data
6ce76104 FK	1	/*
6ce76104 FK	2	* Copyright 2007, Frank A Kingswood <frank@kingswood-consulting.co.uk>
664d5df9 WC	3	* Copyright 2007, Werner Cornelius <werner@cornelius-consult.de>
664d5df9 WC	4	* Copyright 2009, Boris Hajduk <boris@hajduk.org>
6ce76104 FK	5	*
	6	* ch341.c implements a serial port driver for the Winchiphead CH341.
	7	*
	8	* The CH341 device can be used to implement an RS232 asynchronous
	9	* serial port, an IEEE-1284 parallel printer port or a memory-like
	10	* interface. In all cases the CH341 supports an I2C interface as well.
	11	* This driver only supports the asynchronous serial interface.
	12	*
	13	* This program is free software; you can redistribute it and/or
	14	* modify it under the terms of the GNU General Public License version
	15	* 2 as published by the Free Software Foundation.
	16	*/
	17
	18	#include <linux/kernel.h>
	19	#include <linux/init.h>
	20	#include <linux/tty.h>
	21	#include <linux/module.h>
	22	#include <linux/usb.h>
	23	#include <linux/usb/serial.h>
	24	#include <linux/serial.h>
	25
664d5df9	26	#define DEFAULT_BAUD_RATE 9600
6ce76104 FK	27	#define DEFAULT_TIMEOUT 1000
6ce76104 FK	28
664d5df9 WC	29	/* flags for IO-Bits */
	30	#define CH341_BIT_RTS (1 << 6)
	31	#define CH341_BIT_DTR (1 << 5)
	32
	33	/******************************/
	34	/* interrupt pipe definitions */
	35	/******************************/
	36	/* always 4 interrupt bytes */
	37	/* first irq byte normally 0x08 */
	38	/* second irq byte base 0x7d + below */
	39	/* third irq byte base 0x94 + below */
	40	/* fourth irq byte normally 0xee */
	41
	42	/* second interrupt byte */
	43	#define CH341_MULT_STAT 0x04 /* multiple status since last interrupt event */
	44
	45	/* status returned in third interrupt answer byte, inverted in data
	46	from irq */
	47	#define CH341_BIT_CTS 0x01
	48	#define CH341_BIT_DSR 0x02
	49	#define CH341_BIT_RI 0x04
	50	#define CH341_BIT_DCD 0x08
	51	#define CH341_BITS_MODEM_STAT 0x0f /* all bits */
	52
	53	/*******************************/
	54	/* baudrate calculation factor */
	55	/*******************************/
	56	#define CH341_BAUDBASE_FACTOR 1532620800
	57	#define CH341_BAUDBASE_DIVMAX 3
	58
492896f0 TS	59	/* Break support - the information used to implement this was gleaned from
	60	* the Net/FreeBSD uchcom.c driver by Takanori Watanabe. Domo arigato.
	61	*/
	62
	63	#define CH341_REQ_WRITE_REG 0x9A
	64	#define CH341_REQ_READ_REG 0x95
	65	#define CH341_REG_BREAK1 0x05
	66	#define CH341_REG_BREAK2 0x18
	67	#define CH341_NBREAK_BITS_REG1 0x01
	68	#define CH341_NBREAK_BITS_REG2 0x40
	69
	70
6ce76104 FK	71	static int debug;
	72
	73	static struct usb_device_id id_table [] = {
	74	{ USB_DEVICE(0x4348, 0x5523) },
82078234	75	{ USB_DEVICE(0x1a86, 0x7523) },
6ce76104 FK	76	{ },
	77	};
	78	MODULE_DEVICE_TABLE(usb, id_table);
	79
	80	struct ch341_private {
664d5df9 WC	81	spinlock_t lock; /* access lock */
	82	wait_queue_head_t delta_msr_wait; /* wait queue for modem status */
	83	unsigned baud_rate; /* set baud rate */
	84	u8 line_control; /* set line control value RTS/DTR */
	85	u8 line_status; /* active status of modem control inputs */
	86	u8 multi_status_change; /* status changed multiple since last call */
6ce76104 FK	87	};
	88
	89	static int ch341_control_out(struct usb_device *dev, u8 request,
	90	u16 value, u16 index)
	91	{
	92	int r;
	93	dbg("ch341_control_out(%02x,%02x,%04x,%04x)", USB_DIR_OUT\|0x40,
	94	(int)request, (int)value, (int)index);
	95
	96	r = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request,
	97	USB_TYPE_VENDOR \| USB_RECIP_DEVICE \| USB_DIR_OUT,
	98	value, index, NULL, 0, DEFAULT_TIMEOUT);
	99
	100	return r;
	101	}
	102
	103	static int ch341_control_in(struct usb_device *dev,
	104	u8 request, u16 value, u16 index,
	105	char *buf, unsigned bufsize)
	106	{
	107	int r;
	108	dbg("ch341_control_in(%02x,%02x,%04x,%04x,%p,%u)", USB_DIR_IN\|0x40,
	109	(int)request, (int)value, (int)index, buf, (int)bufsize);
	110
	111	r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request,
	112	USB_TYPE_VENDOR \| USB_RECIP_DEVICE \| USB_DIR_IN,
	113	value, index, buf, bufsize, DEFAULT_TIMEOUT);
	114	return r;
	115	}
	116
93b6497d AB	117	static int ch341_set_baudrate(struct usb_device *dev,
93b6497d AB	118	struct ch341_private *priv)
6ce76104 FK	119	{
	120	short a, b;
	121	int r;
664d5df9 WC	122	unsigned long factor;
664d5df9 WC	123	short divisor;
6ce76104 FK	124
6ce76104 FK	125	dbg("ch341_set_baudrate(%d)", priv->baud_rate);
664d5df9 WC	126
664d5df9 WC	127	if (!priv->baud_rate)
6ce76104	128	return -EINVAL;
664d5df9 WC	129	factor = (CH341_BAUDBASE_FACTOR / priv->baud_rate);
	130	divisor = CH341_BAUDBASE_DIVMAX;
	131
	132	while ((factor > 0xfff0) && divisor) {
	133	factor >>= 3;
	134	divisor--;
6ce76104 FK	135	}
6ce76104 FK	136
664d5df9 WC	137	if (factor > 0xfff0)
	138	return -EINVAL;
	139
	140	factor = 0x10000 - factor;
	141	a = (factor & 0xff00) \| divisor;
	142	b = factor & 0xff;
	143
6ce76104 FK	144	r = ch341_control_out(dev, 0x9a, 0x1312, a);
	145	if (!r)
	146	r = ch341_control_out(dev, 0x9a, 0x0f2c, b);
	147
	148	return r;
	149	}
	150
664d5df9	151	static int ch341_set_handshake(struct usb_device *dev, u8 control)
6ce76104	152	{
664d5df9 WC	153	dbg("ch341_set_handshake(0x%02x)", control);
664d5df9 WC	154	return ch341_control_out(dev, 0xa4, ~control, 0);
6ce76104 FK	155	}
6ce76104 FK	156
664d5df9	157	static int ch341_get_status(struct usb_device dev, struct ch341_private priv)
6ce76104 FK	158	{
	159	char *buffer;
	160	int r;
	161	const unsigned size = 8;
664d5df9	162	unsigned long flags;
6ce76104 FK	163
	164	dbg("ch341_get_status()");
	165
	166	buffer = kmalloc(size, GFP_KERNEL);
	167	if (!buffer)
	168	return -ENOMEM;
	169
	170	r = ch341_control_in(dev, 0x95, 0x0706, 0, buffer, size);
c4d0f8cb	171	if (r < 0)
6ce76104 FK	172	goto out;
6ce76104 FK	173
664d5df9 WC	174	/* setup the private status if available */
	175	if (r == 2) {
	176	r = 0;
	177	spin_lock_irqsave(&priv->lock, flags);
	178	priv->line_status = (~(*buffer)) & CH341_BITS_MODEM_STAT;
	179	priv->multi_status_change = 0;
	180	spin_unlock_irqrestore(&priv->lock, flags);
	181	} else
	182	r = -EPROTO;
6ce76104 FK	183
	184	out: kfree(buffer);
	185	return r;
	186	}
	187
	188	/* -------------------------------------------------------------------------- */
	189
93b6497d	190	static int ch341_configure(struct usb_device dev, struct ch341_private priv)
6ce76104 FK	191	{
	192	char *buffer;
	193	int r;
	194	const unsigned size = 8;
	195
	196	dbg("ch341_configure()");
	197
	198	buffer = kmalloc(size, GFP_KERNEL);
	199	if (!buffer)
	200	return -ENOMEM;
	201
	202	/* expect two bytes 0x27 0x00 */
	203	r = ch341_control_in(dev, 0x5f, 0, 0, buffer, size);
	204	if (r < 0)
	205	goto out;
	206
	207	r = ch341_control_out(dev, 0xa1, 0, 0);
	208	if (r < 0)
	209	goto out;
	210
	211	r = ch341_set_baudrate(dev, priv);
	212	if (r < 0)
	213	goto out;
	214
	215	/* expect two bytes 0x56 0x00 */
	216	r = ch341_control_in(dev, 0x95, 0x2518, 0, buffer, size);
	217	if (r < 0)
	218	goto out;
	219
	220	r = ch341_control_out(dev, 0x9a, 0x2518, 0x0050);
	221	if (r < 0)
	222	goto out;
	223
	224	/* expect 0xff 0xee */
664d5df9	225	r = ch341_get_status(dev, priv);
6ce76104 FK	226	if (r < 0)
	227	goto out;
	228
	229	r = ch341_control_out(dev, 0xa1, 0x501f, 0xd90a);
	230	if (r < 0)
	231	goto out;
	232
	233	r = ch341_set_baudrate(dev, priv);
	234	if (r < 0)
	235	goto out;
	236
664d5df9	237	r = ch341_set_handshake(dev, priv->line_control);
6ce76104 FK	238	if (r < 0)
	239	goto out;
	240
	241	/* expect 0x9f 0xee */
664d5df9	242	r = ch341_get_status(dev, priv);
6ce76104 FK	243
	244	out: kfree(buffer);
	245	return r;
	246	}
	247
	248	/* allocate private data */
	249	static int ch341_attach(struct usb_serial *serial)
	250	{
	251	struct ch341_private *priv;
	252	int r;
	253
	254	dbg("ch341_attach()");
	255
	256	/* private data */
	257	priv = kzalloc(sizeof(struct ch341_private), GFP_KERNEL);
	258	if (!priv)
	259	return -ENOMEM;
	260
664d5df9 WC	261	spin_lock_init(&priv->lock);
664d5df9 WC	262	init_waitqueue_head(&priv->delta_msr_wait);
6ce76104	263	priv->baud_rate = DEFAULT_BAUD_RATE;
664d5df9	264	priv->line_control = CH341_BIT_RTS \| CH341_BIT_DTR;
6ce76104 FK	265
	266	r = ch341_configure(serial->dev, priv);
	267	if (r < 0)
	268	goto error;
	269
	270	usb_set_serial_port_data(serial->port[0], priv);
	271	return 0;
	272
	273	error: kfree(priv);
	274	return r;
	275	}
	276
335f8514 AC	277	static int ch341_carrier_raised(struct usb_serial_port *port)
	278	{
	279	struct ch341_private *priv = usb_get_serial_port_data(port);
	280	if (priv->line_status & CH341_BIT_DCD)
	281	return 1;
	282	return 0;
	283	}
	284
	285	static void ch341_dtr_rts(struct usb_serial_port *port, int on)
664d5df9 WC	286	{
	287	struct ch341_private *priv = usb_get_serial_port_data(port);
	288	unsigned long flags;
664d5df9	289
335f8514 AC	290	dbg("%s - port %d", __func__, port->number);
	291	/* drop DTR and RTS */
	292	spin_lock_irqsave(&priv->lock, flags);
	293	if (on)
	294	priv->line_control \|= CH341_BIT_RTS \| CH341_BIT_DTR;
	295	else
	296	priv->line_control &= ~(CH341_BIT_RTS \| CH341_BIT_DTR);
	297	spin_unlock_irqrestore(&priv->lock, flags);
	298	ch341_set_handshake(port->serial->dev, priv->line_control);
	299	wake_up_interruptible(&priv->delta_msr_wait);
	300	}
	301
	302	static void ch341_close(struct usb_serial_port *port)
	303	{
664d5df9 WC	304	dbg("%s - port %d", __func__, port->number);
	305
	306	/* shutdown our urbs */
	307	dbg("%s - shutting down urbs", __func__);
	308	usb_kill_urb(port->write_urb);
	309	usb_kill_urb(port->read_urb);
	310	usb_kill_urb(port->interrupt_in_urb);
664d5df9 WC	311	}
	312
	313
6ce76104	314	/* open this device, set default parameters */
a509a7e4	315	static int ch341_open(struct tty_struct tty, struct usb_serial_port port)
6ce76104 FK	316	{
	317	struct usb_serial *serial = port->serial;
	318	struct ch341_private *priv = usb_get_serial_port_data(serial->port[0]);
	319	int r;
	320
	321	dbg("ch341_open()");
	322
	323	priv->baud_rate = DEFAULT_BAUD_RATE;
6ce76104 FK	324
	325	r = ch341_configure(serial->dev, priv);
	326	if (r)
	327	goto out;
	328
664d5df9	329	r = ch341_set_handshake(serial->dev, priv->line_control);
6ce76104 FK	330	if (r)
	331	goto out;
	332
	333	r = ch341_set_baudrate(serial->dev, priv);
	334	if (r)
	335	goto out;
	336
664d5df9 WC	337	dbg("%s - submitting interrupt urb", __func__);
	338	port->interrupt_in_urb->dev = serial->dev;
	339	r = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
	340	if (r) {
	341	dev_err(&port->dev, "%s - failed submitting interrupt urb,"
	342	" error %d\n", __func__, r);
335f8514	343	ch341_close(port);
664d5df9 WC	344	return -EPROTO;
	345	}
	346
a509a7e4	347	r = usb_serial_generic_open(tty, port);
6ce76104 FK	348
	349	out: return r;
	350	}
	351
	352	/* Old_termios contains the original termios settings and
	353	* tty->termios contains the new setting to be used.
	354	*/
95da310e AC	355	static void ch341_set_termios(struct tty_struct *tty,
95da310e AC	356	struct usb_serial_port port, struct ktermios old_termios)
6ce76104 FK	357	{
6ce76104 FK	358	struct ch341_private *priv = usb_get_serial_port_data(port);
6ce76104	359	unsigned baud_rate;
664d5df9	360	unsigned long flags;
6ce76104 FK	361
	362	dbg("ch341_set_termios()");
	363
6ce76104 FK	364	baud_rate = tty_get_baud_rate(tty);
6ce76104 FK	365
664d5df9 WC	366	priv->baud_rate = baud_rate;
	367
	368	if (baud_rate) {
	369	spin_lock_irqsave(&priv->lock, flags);
	370	priv->line_control \|= (CH341_BIT_DTR \| CH341_BIT_RTS);
	371	spin_unlock_irqrestore(&priv->lock, flags);
	372	ch341_set_baudrate(port->serial->dev, priv);
	373	} else {
	374	spin_lock_irqsave(&priv->lock, flags);
	375	priv->line_control &= ~(CH341_BIT_DTR \| CH341_BIT_RTS);
	376	spin_unlock_irqrestore(&priv->lock, flags);
6ce76104 FK	377	}
6ce76104 FK	378
664d5df9	379	ch341_set_handshake(port->serial->dev, priv->line_control);
6ce76104 FK	380
	381	/* Unimplemented:
	382	* (cflag & CSIZE) : data bits [5, 8]
	383	* (cflag & PARENB) : parity {NONE, EVEN, ODD}
	384	* (cflag & CSTOPB) : stop bits [1, 2]
	385	*/
664d5df9 WC	386	}
664d5df9 WC	387
492896f0 TS	388	static void ch341_break_ctl(struct tty_struct *tty, int break_state)
	389	{
	390	const uint16_t ch341_break_reg =
	391	CH341_REG_BREAK1 \| ((uint16_t) CH341_REG_BREAK2 << 8);
	392	struct usb_serial_port *port = tty->driver_data;
	393	int r;
	394	uint16_t reg_contents;
	395	uint8_t break_reg[2];
	396
	397	dbg("%s()", __func__);
	398
	399	r = ch341_control_in(port->serial->dev, CH341_REQ_READ_REG,
	400	ch341_break_reg, 0, break_reg, sizeof(break_reg));
	401	if (r < 0) {
	402	printk(KERN_WARNING "%s: USB control read error whilst getting"
	403	" break register contents.\n", __FILE__);
	404	return;
	405	}
	406	dbg("%s - initial ch341 break register contents - reg1: %x, reg2: %x",
	407	__func__, break_reg[0], break_reg[1]);
	408	if (break_state != 0) {
	409	dbg("%s - Enter break state requested", __func__);
	410	break_reg[0] &= ~CH341_NBREAK_BITS_REG1;
	411	break_reg[1] &= ~CH341_NBREAK_BITS_REG2;
	412	} else {
	413	dbg("%s - Leave break state requested", __func__);
	414	break_reg[0] \|= CH341_NBREAK_BITS_REG1;
	415	break_reg[1] \|= CH341_NBREAK_BITS_REG2;
	416	}
	417	dbg("%s - New ch341 break register contents - reg1: %x, reg2: %x",
	418	__func__, break_reg[0], break_reg[1]);
	419	reg_contents = (uint16_t)break_reg[0] \| ((uint16_t)break_reg[1] << 8);
	420	r = ch341_control_out(port->serial->dev, CH341_REQ_WRITE_REG,
	421	ch341_break_reg, reg_contents);
	422	if (r < 0)
	423	printk(KERN_WARNING "%s: USB control write error whilst setting"
	424	" break register contents.\n", __FILE__);
	425	}
	426
664d5df9 WC	427	static int ch341_tiocmset(struct tty_struct tty, struct file file,
	428	unsigned int set, unsigned int clear)
	429	{
	430	struct usb_serial_port *port = tty->driver_data;
	431	struct ch341_private *priv = usb_get_serial_port_data(port);
	432	unsigned long flags;
	433	u8 control;
	434
	435	spin_lock_irqsave(&priv->lock, flags);
	436	if (set & TIOCM_RTS)
	437	priv->line_control \|= CH341_BIT_RTS;
	438	if (set & TIOCM_DTR)
	439	priv->line_control \|= CH341_BIT_DTR;
	440	if (clear & TIOCM_RTS)
	441	priv->line_control &= ~CH341_BIT_RTS;
	442	if (clear & TIOCM_DTR)
	443	priv->line_control &= ~CH341_BIT_DTR;
	444	control = priv->line_control;
	445	spin_unlock_irqrestore(&priv->lock, flags);
	446
	447	return ch341_set_handshake(port->serial->dev, control);
	448	}
	449
	450	static void ch341_read_int_callback(struct urb *urb)
	451	{
	452	struct usb_serial_port port = (struct usb_serial_port ) urb->context;
	453	unsigned char *data = urb->transfer_buffer;
	454	unsigned int actual_length = urb->actual_length;
	455	int status;
	456
	457	dbg("%s (%d)", __func__, port->number);
	458
	459	switch (urb->status) {
	460	case 0:
	461	/* success */
	462	break;
	463	case -ECONNRESET:
	464	case -ENOENT:
	465	case -ESHUTDOWN:
	466	/* this urb is terminated, clean up */
	467	dbg("%s - urb shutting down with status: %d", __func__,
	468	urb->status);
	469	return;
	470	default:
	471	dbg("%s - nonzero urb status received: %d", __func__,
	472	urb->status);
	473	goto exit;
	474	}
	475
	476	usb_serial_debug_data(debug, &port->dev, __func__,
	477	urb->actual_length, urb->transfer_buffer);
	478
	479	if (actual_length >= 4) {
	480	struct ch341_private *priv = usb_get_serial_port_data(port);
	481	unsigned long flags;
	482
	483	spin_lock_irqsave(&priv->lock, flags);
	484	priv->line_status = (~(data[2])) & CH341_BITS_MODEM_STAT;
	485	if ((data[1] & CH341_MULT_STAT))
	486	priv->multi_status_change = 1;
	487	spin_unlock_irqrestore(&priv->lock, flags);
	488	wake_up_interruptible(&priv->delta_msr_wait);
	489	}
	490
491	exit:
492	status = usb_submit_urb(urb, GFP_ATOMIC);
493	if (status)
494	dev_err(&urb->dev->dev,
495	"%s - usb_submit_urb failed with result %d\n",
496	__func__, status);
497	}
498
499	static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
500	{
501	struct ch341_private *priv = usb_get_serial_port_data(port);
502	unsigned long flags;
503	u8 prevstatus;
504	u8 status;
505	u8 changed;
506	u8 multi_change = 0;
507
508	spin_lock_irqsave(&priv->lock, flags);
509	prevstatus = priv->line_status;
510	priv->multi_status_change = 0;
511	spin_unlock_irqrestore(&priv->lock, flags);
512
513	while (!multi_change) {
514	interruptible_sleep_on(&priv->delta_msr_wait);
515	/* see if a signal did it */
516	if (signal_pending(current))
517	return -ERESTARTSYS;
518
519	spin_lock_irqsave(&priv->lock, flags);
520	status = priv->line_status;
521	multi_change = priv->multi_status_change;
522	spin_unlock_irqrestore(&priv->lock, flags);
523
524	changed = prevstatus ^ status;
525
526	if (((arg & TIOCM_RNG) && (changed & CH341_BIT_RI)) \|\|
527	((arg & TIOCM_DSR) && (changed & CH341_BIT_DSR)) \|\|
528	((arg & TIOCM_CD) && (changed & CH341_BIT_DCD)) \|\|
529	((arg & TIOCM_CTS) && (changed & CH341_BIT_CTS))) {
530	return 0;
531	}
532	prevstatus = status;
533	}
534
535	return 0;
536	}
537
538	/static int ch341_ioctl(struct usb_serial_port port, struct file file,/
539	static int ch341_ioctl(struct tty_struct tty, struct file file,
540	unsigned int cmd, unsigned long arg)
541	{
542	struct usb_serial_port *port = tty->driver_data;
543	dbg("%s (%d) cmd = 0x%04x", __func__, port->number, cmd);
544
545	switch (cmd) {
546	case TIOCMIWAIT:
547	dbg("%s (%d) TIOCMIWAIT", __func__, port->number);
548	return wait_modem_info(port, arg);
549
550	default:
551	dbg("%s not supported = 0x%04x", __func__, cmd);
552	break;
553	}
554
555	return -ENOIOCTLCMD;
556	}
557
558	static int ch341_tiocmget(struct tty_struct tty, struct file file)
559	{
560	struct usb_serial_port *port = tty->driver_data;
561	struct ch341_private *priv = usb_get_serial_port_data(port);
562	unsigned long flags;
563	u8 mcr;
564	u8 status;
565	unsigned int result;
566
567	dbg("%s (%d)", __func__, port->number);
568
569	spin_lock_irqsave(&priv->lock, flags);
570	mcr = priv->line_control;
571	status = priv->line_status;
572	spin_unlock_irqrestore(&priv->lock, flags);
573
574	result = ((mcr & CH341_BIT_DTR) ? TIOCM_DTR : 0)
575	\| ((mcr & CH341_BIT_RTS) ? TIOCM_RTS : 0)
576	\| ((status & CH341_BIT_CTS) ? TIOCM_CTS : 0)
577	\| ((status & CH341_BIT_DSR) ? TIOCM_DSR : 0)
578	\| ((status & CH341_BIT_RI) ? TIOCM_RI : 0)
579	\| ((status & CH341_BIT_DCD) ? TIOCM_CD : 0);
580
581	dbg("%s - result = %x", __func__, result);
73f59308	582
664d5df9	583	return result;
6ce76104 FK	584	}
6ce76104 FK	585
1ded7ea4 ML	586
	587	static int ch341_reset_resume(struct usb_interface *intf)
	588	{
	589	struct usb_device *dev = interface_to_usbdev(intf);
	590	struct usb_serial *serial = NULL;
	591	struct ch341_private *priv;
	592
	593	serial = usb_get_intfdata(intf);
	594	priv = usb_get_serial_port_data(serial->port[0]);
	595
	596	/reconfigure ch341 serial port after bus-reset/
	597	ch341_configure(dev, priv);
	598
	599	usb_serial_resume(intf);
	600
	601	return 0;
	602	}
	603
6ce76104 FK	604	static struct usb_driver ch341_driver = {
	605	.name = "ch341",
	606	.probe = usb_serial_probe,
	607	.disconnect = usb_serial_disconnect,
1ded7ea4 ML	608	.suspend = usb_serial_suspend,
	609	.resume = usb_serial_resume,
	610	.reset_resume = ch341_reset_resume,
6ce76104 FK	611	.id_table = id_table,
6ce76104 FK	612	.no_dynamic_id = 1,
1ded7ea4	613	.supports_autosuspend = 1,
6ce76104 FK	614	};
	615
	616	static struct usb_serial_driver ch341_device = {
	617	.driver = {
	618	.owner = THIS_MODULE,
	619	.name = "ch341-uart",
	620	},
664d5df9 WC	621	.id_table = id_table,
	622	.usb_driver = &ch341_driver,
	623	.num_ports = 1,
	624	.open = ch341_open,
335f8514 AC	625	.dtr_rts = ch341_dtr_rts,
335f8514 AC	626	.carrier_raised = ch341_carrier_raised,
664d5df9 WC	627	.close = ch341_close,
	628	.ioctl = ch341_ioctl,
	629	.set_termios = ch341_set_termios,
492896f0	630	.break_ctl = ch341_break_ctl,
664d5df9 WC	631	.tiocmget = ch341_tiocmget,
	632	.tiocmset = ch341_tiocmset,
	633	.read_int_callback = ch341_read_int_callback,
	634	.attach = ch341_attach,
6ce76104 FK	635	};
	636
	637	static int __init ch341_init(void)
	638	{
	639	int retval;
	640
	641	retval = usb_serial_register(&ch341_device);
	642	if (retval)
	643	return retval;
	644	retval = usb_register(&ch341_driver);
	645	if (retval)
	646	usb_serial_deregister(&ch341_device);
	647	return retval;
	648	}
	649
	650	static void __exit ch341_exit(void)
	651	{
	652	usb_deregister(&ch341_driver);
	653	usb_serial_deregister(&ch341_device);
	654	}
	655
	656	module_init(ch341_init);
	657	module_exit(ch341_exit);
	658	MODULE_LICENSE("GPL");
	659
	660	module_param(debug, bool, S_IRUGO \| S_IWUSR);
	661	MODULE_PARM_DESC(debug, "Debug enabled or not");
	662
	663	/* EOF ch341.c */