[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/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_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 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 line_control; /* set line control value RTS/DTR */
	u8 line_status; /* active status of modem control inputs */
};

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

	dev_dbg(&dev->dev, "ch341_control_out(%02x,%02x,%04x,%04x)\n",
		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;

	dev_dbg(&dev->dev, "ch341_control_in(%02x,%02x,%04x,%04x,%p,%u)\n",
		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;

	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)
{
	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;

	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;
		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;

	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;
}

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;
	priv->line_control = CH341_BIT_RTS | CH341_BIT_DTR;

	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->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;

	/* 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);
}

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 usb_serial *serial = port->serial;
	struct ch341_private *priv = usb_get_serial_port_data(port);
	int r;

	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;

	dev_dbg(&port->dev, "%s - submitting interrupt urb", __func__);
	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);
		goto out;
	}

	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;

	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;

	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_REG1;
		break_reg[1] &= ~CH341_NBREAK_BITS_REG2;
	} else {
		dev_dbg(&port->dev, "%s - Leave break state requested\n", __func__);
		break_reg[0] |= CH341_NBREAK_BITS_REG1;
		break_reg[1] |= CH341_NBREAK_BITS_REG2;
	}
	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->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_update_line_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->line_status;
	priv->line_status = 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_line_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->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);

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

	return result;
}

static int ch341_reset_resume(struct usb_serial *serial)
{
	struct ch341_private *priv;

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

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

	return 0;
}

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");
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>
6ce76104 FK	19	#include <linux/tty.h>
6ce76104 FK	20	#include <linux/module.h>
5a0e3ad6	21	#include <linux/slab.h>
6ce76104 FK	22	#include <linux/usb.h>
	23	#include <linux/usb/serial.h>
	24	#include <linux/serial.h>
5be796f0	25	#include <asm/unaligned.h>
6ce76104	26
664d5df9	27	#define DEFAULT_BAUD_RATE 9600
6ce76104 FK	28	#define DEFAULT_TIMEOUT 1000
6ce76104 FK	29
664d5df9 WC	30	/* flags for IO-Bits */
	31	#define CH341_BIT_RTS (1 << 6)
	32	#define CH341_BIT_DTR (1 << 5)
	33
	34	/******************************/
	35	/* interrupt pipe definitions */
	36	/******************************/
	37	/* always 4 interrupt bytes */
	38	/* first irq byte normally 0x08 */
	39	/* second irq byte base 0x7d + below */
	40	/* third irq byte base 0x94 + below */
	41	/* fourth irq byte normally 0xee */
	42
	43	/* second interrupt byte */
	44	#define CH341_MULT_STAT 0x04 /* multiple status since last interrupt event */
	45
	46	/* status returned in third interrupt answer byte, inverted in data
	47	from irq */
	48	#define CH341_BIT_CTS 0x01
	49	#define CH341_BIT_DSR 0x02
	50	#define CH341_BIT_RI 0x04
	51	#define CH341_BIT_DCD 0x08
	52	#define CH341_BITS_MODEM_STAT 0x0f /* all bits */
	53
	54	/*******************************/
	55	/* baudrate calculation factor */
	56	/*******************************/
	57	#define CH341_BAUDBASE_FACTOR 1532620800
	58	#define CH341_BAUDBASE_DIVMAX 3
	59
492896f0 TS	60	/* Break support - the information used to implement this was gleaned from
	61	* the Net/FreeBSD uchcom.c driver by Takanori Watanabe. Domo arigato.
	62	*/
	63
	64	#define CH341_REQ_WRITE_REG 0x9A
	65	#define CH341_REQ_READ_REG 0x95
	66	#define CH341_REG_BREAK1 0x05
	67	#define CH341_REG_BREAK2 0x18
	68	#define CH341_NBREAK_BITS_REG1 0x01
	69	#define CH341_NBREAK_BITS_REG2 0x40
	70
	71
7d40d7e8	72	static const struct usb_device_id id_table[] = {
6ce76104	73	{ USB_DEVICE(0x4348, 0x5523) },
82078234	74	{ USB_DEVICE(0x1a86, 0x7523) },
d0781383	75	{ USB_DEVICE(0x1a86, 0x5523) },
6ce76104 FK	76	{ },
	77	};
	78	MODULE_DEVICE_TABLE(usb, id_table);
	79
	80	struct ch341_private {
664d5df9	81	spinlock_t lock; /* access lock */
664d5df9 WC	82	unsigned baud_rate; /* set baud rate */
	83	u8 line_control; /* set line control value RTS/DTR */
	84	u8 line_status; /* active status of modem control inputs */
6ce76104 FK	85	};
	86
	87	static int ch341_control_out(struct usb_device *dev, u8 request,
	88	u16 value, u16 index)
	89	{
	90	int r;
79cbeeaf GKH	91
	92	dev_dbg(&dev->dev, "ch341_control_out(%02x,%02x,%04x,%04x)\n",
	93	USB_DIR_OUT\|0x40, (int)request, (int)value, (int)index);
6ce76104 FK	94
	95	r = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request,
	96	USB_TYPE_VENDOR \| USB_RECIP_DEVICE \| USB_DIR_OUT,
	97	value, index, NULL, 0, DEFAULT_TIMEOUT);
	98
	99	return r;
	100	}
	101
	102	static int ch341_control_in(struct usb_device *dev,
	103	u8 request, u16 value, u16 index,
	104	char *buf, unsigned bufsize)
	105	{
	106	int r;
79cbeeaf GKH	107
	108	dev_dbg(&dev->dev, "ch341_control_in(%02x,%02x,%04x,%04x,%p,%u)\n",
	109	USB_DIR_IN\|0x40, (int)request, (int)value, (int)index, buf,
	110	(int)bufsize);
6ce76104 FK	111
	112	r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request,
	113	USB_TYPE_VENDOR \| USB_RECIP_DEVICE \| USB_DIR_IN,
	114	value, index, buf, bufsize, DEFAULT_TIMEOUT);
	115	return r;
	116	}
	117
93b6497d AB	118	static int ch341_set_baudrate(struct usb_device *dev,
93b6497d AB	119	struct ch341_private *priv)
6ce76104 FK	120	{
	121	short a, b;
	122	int r;
664d5df9 WC	123	unsigned long factor;
664d5df9 WC	124	short divisor;
6ce76104	125
664d5df9	126	if (!priv->baud_rate)
6ce76104	127	return -EINVAL;
664d5df9 WC	128	factor = (CH341_BAUDBASE_FACTOR / priv->baud_rate);
	129	divisor = CH341_BAUDBASE_DIVMAX;
	130
	131	while ((factor > 0xfff0) && divisor) {
	132	factor >>= 3;
	133	divisor--;
6ce76104 FK	134	}
6ce76104 FK	135
664d5df9 WC	136	if (factor > 0xfff0)
	137	return -EINVAL;
	138
	139	factor = 0x10000 - factor;
	140	a = (factor & 0xff00) \| divisor;
	141	b = factor & 0xff;
	142
6ce76104 FK	143	r = ch341_control_out(dev, 0x9a, 0x1312, a);
	144	if (!r)
	145	r = ch341_control_out(dev, 0x9a, 0x0f2c, b);
	146
	147	return r;
	148	}
	149
664d5df9	150	static int ch341_set_handshake(struct usb_device *dev, u8 control)
6ce76104	151	{
664d5df9	152	return ch341_control_out(dev, 0xa4, ~control, 0);
6ce76104 FK	153	}
6ce76104 FK	154
664d5df9	155	static int ch341_get_status(struct usb_device dev, struct ch341_private priv)
6ce76104 FK	156	{
	157	char *buffer;
	158	int r;
	159	const unsigned size = 8;
664d5df9	160	unsigned long flags;
6ce76104	161
6ce76104 FK	162	buffer = kmalloc(size, GFP_KERNEL);
	163	if (!buffer)
	164	return -ENOMEM;
	165
	166	r = ch341_control_in(dev, 0x95, 0x0706, 0, buffer, size);
c4d0f8cb	167	if (r < 0)
6ce76104 FK	168	goto out;
6ce76104 FK	169
664d5df9 WC	170	/* setup the private status if available */
	171	if (r == 2) {
	172	r = 0;
	173	spin_lock_irqsave(&priv->lock, flags);
	174	priv->line_status = (~(*buffer)) & CH341_BITS_MODEM_STAT;
664d5df9 WC	175	spin_unlock_irqrestore(&priv->lock, flags);
	176	} else
	177	r = -EPROTO;
6ce76104 FK	178
	179	out: kfree(buffer);
	180	return r;
	181	}
	182
	183	/* -------------------------------------------------------------------------- */
	184
93b6497d	185	static int ch341_configure(struct usb_device dev, struct ch341_private priv)
6ce76104 FK	186	{
	187	char *buffer;
	188	int r;
	189	const unsigned size = 8;
	190
6ce76104 FK	191	buffer = kmalloc(size, GFP_KERNEL);
	192	if (!buffer)
	193	return -ENOMEM;
	194
	195	/* expect two bytes 0x27 0x00 */
	196	r = ch341_control_in(dev, 0x5f, 0, 0, buffer, size);
	197	if (r < 0)
	198	goto out;
	199
	200	r = ch341_control_out(dev, 0xa1, 0, 0);
	201	if (r < 0)
	202	goto out;
	203
	204	r = ch341_set_baudrate(dev, priv);
	205	if (r < 0)
	206	goto out;
	207
	208	/* expect two bytes 0x56 0x00 */
	209	r = ch341_control_in(dev, 0x95, 0x2518, 0, buffer, size);
	210	if (r < 0)
	211	goto out;
	212
	213	r = ch341_control_out(dev, 0x9a, 0x2518, 0x0050);
	214	if (r < 0)
	215	goto out;
	216
	217	/* expect 0xff 0xee */
664d5df9	218	r = ch341_get_status(dev, priv);
6ce76104 FK	219	if (r < 0)
	220	goto out;
	221
	222	r = ch341_control_out(dev, 0xa1, 0x501f, 0xd90a);
	223	if (r < 0)
	224	goto out;
	225
	226	r = ch341_set_baudrate(dev, priv);
	227	if (r < 0)
	228	goto out;
	229
664d5df9	230	r = ch341_set_handshake(dev, priv->line_control);
6ce76104 FK	231	if (r < 0)
	232	goto out;
	233
	234	/* expect 0x9f 0xee */
664d5df9	235	r = ch341_get_status(dev, priv);
6ce76104 FK	236
	237	out: kfree(buffer);
	238	return r;
	239	}
	240
456c5be5	241	static int ch341_port_probe(struct usb_serial_port *port)
6ce76104 FK	242	{
	243	struct ch341_private *priv;
	244	int r;
	245
6ce76104 FK	246	priv = kzalloc(sizeof(struct ch341_private), GFP_KERNEL);
	247	if (!priv)
	248	return -ENOMEM;
	249
664d5df9	250	spin_lock_init(&priv->lock);
6ce76104	251	priv->baud_rate = DEFAULT_BAUD_RATE;
664d5df9	252	priv->line_control = CH341_BIT_RTS \| CH341_BIT_DTR;
6ce76104	253
456c5be5	254	r = ch341_configure(port->serial->dev, priv);
6ce76104 FK	255	if (r < 0)
	256	goto error;
	257
456c5be5	258	usb_set_serial_port_data(port, priv);
6ce76104 FK	259	return 0;
	260
	261	error: kfree(priv);
	262	return r;
	263	}
	264
456c5be5 JH	265	static int ch341_port_remove(struct usb_serial_port *port)
	266	{
	267	struct ch341_private *priv;
	268
	269	priv = usb_get_serial_port_data(port);
	270	kfree(priv);
	271
	272	return 0;
	273	}
	274
335f8514 AC	275	static int ch341_carrier_raised(struct usb_serial_port *port)
	276	{
	277	struct ch341_private *priv = usb_get_serial_port_data(port);
	278	if (priv->line_status & CH341_BIT_DCD)
	279	return 1;
	280	return 0;
	281	}
	282
	283	static void ch341_dtr_rts(struct usb_serial_port *port, int on)
664d5df9 WC	284	{
	285	struct ch341_private *priv = usb_get_serial_port_data(port);
	286	unsigned long flags;
664d5df9	287
335f8514 AC	288	/* drop DTR and RTS */
	289	spin_lock_irqsave(&priv->lock, flags);
	290	if (on)
	291	priv->line_control \|= CH341_BIT_RTS \| CH341_BIT_DTR;
	292	else
	293	priv->line_control &= ~(CH341_BIT_RTS \| CH341_BIT_DTR);
	294	spin_unlock_irqrestore(&priv->lock, flags);
	295	ch341_set_handshake(port->serial->dev, priv->line_control);
335f8514 AC	296	}
	297
	298	static void ch341_close(struct usb_serial_port *port)
	299	{
f26788da	300	usb_serial_generic_close(port);
664d5df9	301	usb_kill_urb(port->interrupt_in_urb);
664d5df9 WC	302	}
	303
	304
6ce76104	305	/* open this device, set default parameters */
a509a7e4	306	static int ch341_open(struct tty_struct tty, struct usb_serial_port port)
6ce76104 FK	307	{
6ce76104 FK	308	struct usb_serial *serial = port->serial;
456c5be5	309	struct ch341_private *priv = usb_get_serial_port_data(port);
6ce76104 FK	310	int r;
6ce76104 FK	311
6ce76104	312	priv->baud_rate = DEFAULT_BAUD_RATE;
6ce76104 FK	313
	314	r = ch341_configure(serial->dev, priv);
	315	if (r)
	316	goto out;
	317
664d5df9	318	r = ch341_set_handshake(serial->dev, priv->line_control);
6ce76104 FK	319	if (r)
	320	goto out;
	321
	322	r = ch341_set_baudrate(serial->dev, priv);
	323	if (r)
	324	goto out;
	325
79cbeeaf	326	dev_dbg(&port->dev, "%s - submitting interrupt urb", __func__);
664d5df9 WC	327	r = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
	328	if (r) {
	329	dev_err(&port->dev, "%s - failed submitting interrupt urb,"
	330	" error %d\n", __func__, r);
335f8514	331	ch341_close(port);
06946a66	332	goto out;
664d5df9 WC	333	}
664d5df9 WC	334
a509a7e4	335	r = usb_serial_generic_open(tty, port);
6ce76104 FK	336
	337	out: return r;
	338	}
	339
	340	/* Old_termios contains the original termios settings and
	341	* tty->termios contains the new setting to be used.
	342	*/
95da310e AC	343	static void ch341_set_termios(struct tty_struct *tty,
95da310e AC	344	struct usb_serial_port port, struct ktermios old_termios)
6ce76104 FK	345	{
6ce76104 FK	346	struct ch341_private *priv = usb_get_serial_port_data(port);
6ce76104	347	unsigned baud_rate;
664d5df9	348	unsigned long flags;
6ce76104	349
6ce76104 FK	350	baud_rate = tty_get_baud_rate(tty);
6ce76104 FK	351
664d5df9 WC	352	priv->baud_rate = baud_rate;
	353
	354	if (baud_rate) {
	355	spin_lock_irqsave(&priv->lock, flags);
	356	priv->line_control \|= (CH341_BIT_DTR \| CH341_BIT_RTS);
	357	spin_unlock_irqrestore(&priv->lock, flags);
	358	ch341_set_baudrate(port->serial->dev, priv);
	359	} else {
	360	spin_lock_irqsave(&priv->lock, flags);
	361	priv->line_control &= ~(CH341_BIT_DTR \| CH341_BIT_RTS);
	362	spin_unlock_irqrestore(&priv->lock, flags);
6ce76104 FK	363	}
6ce76104 FK	364
664d5df9	365	ch341_set_handshake(port->serial->dev, priv->line_control);
6ce76104 FK	366
	367	/* Unimplemented:
	368	* (cflag & CSIZE) : data bits [5, 8]
	369	* (cflag & PARENB) : parity {NONE, EVEN, ODD}
	370	* (cflag & CSTOPB) : stop bits [1, 2]
	371	*/
664d5df9 WC	372	}
664d5df9 WC	373
492896f0 TS	374	static void ch341_break_ctl(struct tty_struct *tty, int break_state)
	375	{
	376	const uint16_t ch341_break_reg =
	377	CH341_REG_BREAK1 \| ((uint16_t) CH341_REG_BREAK2 << 8);
	378	struct usb_serial_port *port = tty->driver_data;
	379	int r;
	380	uint16_t reg_contents;
f2b5cc83	381	uint8_t *break_reg;
492896f0	382
f2b5cc83	383	break_reg = kmalloc(2, GFP_KERNEL);
10c642d0	384	if (!break_reg)
f2b5cc83	385	return;
f2b5cc83	386
492896f0	387	r = ch341_control_in(port->serial->dev, CH341_REQ_READ_REG,
f2b5cc83	388	ch341_break_reg, 0, break_reg, 2);
492896f0	389	if (r < 0) {
6a9b15fe JH	390	dev_err(&port->dev, "%s - USB control read error (%d)\n",
6a9b15fe JH	391	__func__, r);
f2b5cc83	392	goto out;
492896f0	393	}
79cbeeaf GKH	394	dev_dbg(&port->dev, "%s - initial ch341 break register contents - reg1: %x, reg2: %x\n",
79cbeeaf GKH	395	__func__, break_reg[0], break_reg[1]);
492896f0	396	if (break_state != 0) {
79cbeeaf	397	dev_dbg(&port->dev, "%s - Enter break state requested\n", __func__);
492896f0 TS	398	break_reg[0] &= ~CH341_NBREAK_BITS_REG1;
	399	break_reg[1] &= ~CH341_NBREAK_BITS_REG2;
	400	} else {
79cbeeaf	401	dev_dbg(&port->dev, "%s - Leave break state requested\n", __func__);
492896f0 TS	402	break_reg[0] \|= CH341_NBREAK_BITS_REG1;
	403	break_reg[1] \|= CH341_NBREAK_BITS_REG2;
	404	}
79cbeeaf GKH	405	dev_dbg(&port->dev, "%s - New ch341 break register contents - reg1: %x, reg2: %x\n",
79cbeeaf GKH	406	__func__, break_reg[0], break_reg[1]);
5be796f0	407	reg_contents = get_unaligned_le16(break_reg);
492896f0 TS	408	r = ch341_control_out(port->serial->dev, CH341_REQ_WRITE_REG,
	409	ch341_break_reg, reg_contents);
	410	if (r < 0)
6a9b15fe JH	411	dev_err(&port->dev, "%s - USB control write error (%d)\n",
6a9b15fe JH	412	__func__, r);
f2b5cc83 JH	413	out:
f2b5cc83 JH	414	kfree(break_reg);
492896f0 TS	415	}
492896f0 TS	416
20b9d177	417	static int ch341_tiocmset(struct tty_struct *tty,
664d5df9 WC	418	unsigned int set, unsigned int clear)
	419	{
	420	struct usb_serial_port *port = tty->driver_data;
	421	struct ch341_private *priv = usb_get_serial_port_data(port);
	422	unsigned long flags;
	423	u8 control;
	424
	425	spin_lock_irqsave(&priv->lock, flags);
	426	if (set & TIOCM_RTS)
	427	priv->line_control \|= CH341_BIT_RTS;
	428	if (set & TIOCM_DTR)
	429	priv->line_control \|= CH341_BIT_DTR;
	430	if (clear & TIOCM_RTS)
	431	priv->line_control &= ~CH341_BIT_RTS;
	432	if (clear & TIOCM_DTR)
	433	priv->line_control &= ~CH341_BIT_DTR;
	434	control = priv->line_control;
	435	spin_unlock_irqrestore(&priv->lock, flags);
	436
	437	return ch341_set_handshake(port->serial->dev, control);
	438	}
	439
ac035628 JH	440	static void ch341_update_line_status(struct usb_serial_port *port,
	441	unsigned char *data, size_t len)
	442	{
	443	struct ch341_private *priv = usb_get_serial_port_data(port);
b770081f	444	struct tty_struct *tty;
ac035628	445	unsigned long flags;
b770081f JH	446	u8 status;
b770081f JH	447	u8 delta;
ac035628 JH	448
	449	if (len < 4)
	450	return;
	451
b770081f JH	452	status = ~data[2] & CH341_BITS_MODEM_STAT;
b770081f JH	453
ac035628	454	spin_lock_irqsave(&priv->lock, flags);
b770081f JH	455	delta = status ^ priv->line_status;
b770081f JH	456	priv->line_status = status;
ac035628 JH	457	spin_unlock_irqrestore(&priv->lock, flags);
ac035628 JH	458
fd74b0b1 JH	459	if (data[1] & CH341_MULT_STAT)
	460	dev_dbg(&port->dev, "%s - multiple status change\n", __func__);
	461
d984fe91 JH	462	if (!delta)
	463	return;
	464
5e409a26 JH	465	if (delta & CH341_BIT_CTS)
	466	port->icount.cts++;
	467	if (delta & CH341_BIT_DSR)
	468	port->icount.dsr++;
	469	if (delta & CH341_BIT_RI)
	470	port->icount.rng++;
b770081f	471	if (delta & CH341_BIT_DCD) {
5e409a26	472	port->icount.dcd++;
b770081f JH	473	tty = tty_port_tty_get(&port->port);
b770081f JH	474	if (tty) {
ac035628	475	usb_serial_handle_dcd_change(port, tty,
b770081f JH	476	status & CH341_BIT_DCD);
	477	tty_kref_put(tty);
	478	}
ac035628 JH	479	}
	480
	481	wake_up_interruptible(&port->port.delta_msr_wait);
	482	}
	483
664d5df9 WC	484	static void ch341_read_int_callback(struct urb *urb)
664d5df9 WC	485	{
271ec2d2	486	struct usb_serial_port *port = urb->context;
664d5df9	487	unsigned char *data = urb->transfer_buffer;
271ec2d2	488	unsigned int len = urb->actual_length;
664d5df9 WC	489	int status;
664d5df9 WC	490
664d5df9 WC	491	switch (urb->status) {
	492	case 0:
	493	/* success */
	494	break;
	495	case -ECONNRESET:
	496	case -ENOENT:
	497	case -ESHUTDOWN:
	498	/* this urb is terminated, clean up */
271ec2d2	499	dev_dbg(&urb->dev->dev, "%s - urb shutting down: %d\n",
79cbeeaf	500	__func__, urb->status);
664d5df9 WC	501	return;
664d5df9 WC	502	default:
271ec2d2	503	dev_dbg(&urb->dev->dev, "%s - nonzero urb status: %d\n",
79cbeeaf	504	__func__, urb->status);
664d5df9 WC	505	goto exit;
	506	}
	507
271ec2d2 JH	508	usb_serial_debug_data(&port->dev, __func__, len, data);
271ec2d2 JH	509	ch341_update_line_status(port, data, len);
664d5df9 WC	510	exit:
664d5df9 WC	511	status = usb_submit_urb(urb, GFP_ATOMIC);
271ec2d2 JH	512	if (status) {
271ec2d2 JH	513	dev_err(&urb->dev->dev, "%s - usb_submit_urb failed: %d\n",
664d5df9	514	__func__, status);
271ec2d2	515	}
664d5df9 WC	516	}
664d5df9 WC	517
60b33c13	518	static int ch341_tiocmget(struct tty_struct *tty)
664d5df9 WC	519	{
	520	struct usb_serial_port *port = tty->driver_data;
	521	struct ch341_private *priv = usb_get_serial_port_data(port);
	522	unsigned long flags;
	523	u8 mcr;
	524	u8 status;
	525	unsigned int result;
	526
664d5df9 WC	527	spin_lock_irqsave(&priv->lock, flags);
	528	mcr = priv->line_control;
	529	status = priv->line_status;
	530	spin_unlock_irqrestore(&priv->lock, flags);
	531
	532	result = ((mcr & CH341_BIT_DTR) ? TIOCM_DTR : 0)
	533	\| ((mcr & CH341_BIT_RTS) ? TIOCM_RTS : 0)
	534	\| ((status & CH341_BIT_CTS) ? TIOCM_CTS : 0)
	535	\| ((status & CH341_BIT_DSR) ? TIOCM_DSR : 0)
	536	\| ((status & CH341_BIT_RI) ? TIOCM_RI : 0)
	537	\| ((status & CH341_BIT_DCD) ? TIOCM_CD : 0);
	538
79cbeeaf	539	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
73f59308	540
664d5df9	541	return result;
6ce76104 FK	542	}
6ce76104 FK	543
622b80cf	544	static int ch341_reset_resume(struct usb_serial *serial)
1ded7ea4	545	{
1ded7ea4 ML	546	struct ch341_private *priv;
1ded7ea4 ML	547
1ded7ea4 ML	548	priv = usb_get_serial_port_data(serial->port[0]);
1ded7ea4 ML	549
2bfd1c96 GKH	550	/* reconfigure ch341 serial port after bus-reset */
2bfd1c96 GKH	551	ch341_configure(serial->dev, priv);
1ded7ea4 ML	552
	553	return 0;
	554	}
	555
6ce76104 FK	556	static struct usb_serial_driver ch341_device = {
	557	.driver = {
	558	.owner = THIS_MODULE,
	559	.name = "ch341-uart",
	560	},
664d5df9	561	.id_table = id_table,
664d5df9 WC	562	.num_ports = 1,
664d5df9 WC	563	.open = ch341_open,
335f8514 AC	564	.dtr_rts = ch341_dtr_rts,
335f8514 AC	565	.carrier_raised = ch341_carrier_raised,
664d5df9	566	.close = ch341_close,
664d5df9	567	.set_termios = ch341_set_termios,
492896f0	568	.break_ctl = ch341_break_ctl,
664d5df9 WC	569	.tiocmget = ch341_tiocmget,
664d5df9 WC	570	.tiocmset = ch341_tiocmset,
5e409a26	571	.tiocmiwait = usb_serial_generic_tiocmiwait,
664d5df9	572	.read_int_callback = ch341_read_int_callback,
456c5be5 JH	573	.port_probe = ch341_port_probe,
456c5be5 JH	574	.port_remove = ch341_port_remove,
1c1eaba8	575	.reset_resume = ch341_reset_resume,
6ce76104 FK	576	};
6ce76104 FK	577
08a4f6bc AS	578	static struct usb_serial_driver * const serial_drivers[] = {
	579	&ch341_device, NULL
	580	};
	581
68e24113	582	module_usb_serial_driver(serial_drivers, id_table);
6ce76104	583
6ce76104	584	MODULE_LICENSE("GPL");