[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/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 */
	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;

	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;
		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;

	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;

	/* 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;

	/* 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)
{
	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(serial->port[0]);
	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) {
		dev_err(&port->dev, "%s - kmalloc failed\n", __func__);
		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_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;

	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 with status: %d\n",
			__func__, urb->status);
		return;
	default:
		dev_dbg(&urb->dev->dev, "%s - nonzero urb status received: %d\n",
			__func__, urb->status);
		goto exit;
	}

	usb_serial_debug_data(&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;
		u8 prev_line_status = priv->line_status;

		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);

		if ((priv->line_status ^ prev_line_status) & CH341_BIT_DCD) {
			struct tty_struct *tty = tty_port_tty_get(&port->port);
			if (tty)
				usb_serial_handle_dcd_change(port, tty,
					    priv->line_status & CH341_BIT_DCD);
			tty_kref_put(tty);
		}

		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 tty_struct *tty,
			unsigned int cmd, unsigned long arg)
{
	struct usb_serial_port *port = tty->driver_data;

	dev_dbg(&port->dev, "%s (%d) cmd = 0x%04x\n", __func__, port->number, cmd);

	switch (cmd) {
	case TIOCMIWAIT:
		dev_dbg(&port->dev, "%s (%d) TIOCMIWAIT\n", __func__,  port->number);
		return wait_modem_info(port, arg);

	default:
		dev_dbg(&port->dev, "%s not supported = 0x%04x\n", __func__, cmd);
		break;
	}

	return -ENOIOCTLCMD;
}

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,
	.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,
	.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>
	19	#include <linux/init.h>
	20	#include <linux/tty.h>
	21	#include <linux/module.h>
5a0e3ad6	22	#include <linux/slab.h>
6ce76104 FK	23	#include <linux/usb.h>
	24	#include <linux/usb/serial.h>
	25	#include <linux/serial.h>
5be796f0	26	#include <asm/unaligned.h>
6ce76104	27
664d5df9	28	#define DEFAULT_BAUD_RATE 9600
6ce76104 FK	29	#define DEFAULT_TIMEOUT 1000
6ce76104 FK	30
664d5df9 WC	31	/* flags for IO-Bits */
	32	#define CH341_BIT_RTS (1 << 6)
	33	#define CH341_BIT_DTR (1 << 5)
	34
	35	/******************************/
	36	/* interrupt pipe definitions */
	37	/******************************/
	38	/* always 4 interrupt bytes */
	39	/* first irq byte normally 0x08 */
	40	/* second irq byte base 0x7d + below */
	41	/* third irq byte base 0x94 + below */
	42	/* fourth irq byte normally 0xee */
	43
	44	/* second interrupt byte */
	45	#define CH341_MULT_STAT 0x04 /* multiple status since last interrupt event */
	46
	47	/* status returned in third interrupt answer byte, inverted in data
	48	from irq */
	49	#define CH341_BIT_CTS 0x01
	50	#define CH341_BIT_DSR 0x02
	51	#define CH341_BIT_RI 0x04
	52	#define CH341_BIT_DCD 0x08
	53	#define CH341_BITS_MODEM_STAT 0x0f /* all bits */
	54
	55	/*******************************/
	56	/* baudrate calculation factor */
	57	/*******************************/
	58	#define CH341_BAUDBASE_FACTOR 1532620800
	59	#define CH341_BAUDBASE_DIVMAX 3
	60
492896f0 TS	61	/* Break support - the information used to implement this was gleaned from
	62	* the Net/FreeBSD uchcom.c driver by Takanori Watanabe. Domo arigato.
	63	*/
	64
	65	#define CH341_REQ_WRITE_REG 0x9A
	66	#define CH341_REQ_READ_REG 0x95
	67	#define CH341_REG_BREAK1 0x05
	68	#define CH341_REG_BREAK2 0x18
	69	#define CH341_NBREAK_BITS_REG1 0x01
	70	#define CH341_NBREAK_BITS_REG2 0x40
	71
	72
7d40d7e8	73	static const struct usb_device_id id_table[] = {
6ce76104	74	{ USB_DEVICE(0x4348, 0x5523) },
82078234	75	{ USB_DEVICE(0x1a86, 0x7523) },
d0781383	76	{ USB_DEVICE(0x1a86, 0x5523) },
6ce76104 FK	77	{ },
	78	};
	79	MODULE_DEVICE_TABLE(usb, id_table);
	80
	81	struct ch341_private {
664d5df9 WC	82	spinlock_t lock; /* access lock */
	83	wait_queue_head_t delta_msr_wait; /* wait queue for modem status */
	84	unsigned baud_rate; /* set baud rate */
	85	u8 line_control; /* set line control value RTS/DTR */
	86	u8 line_status; /* active status of modem control inputs */
	87	u8 multi_status_change; /* status changed multiple since last call */
6ce76104 FK	88	};
	89
	90	static int ch341_control_out(struct usb_device *dev, u8 request,
	91	u16 value, u16 index)
	92	{
	93	int r;
79cbeeaf GKH	94
	95	dev_dbg(&dev->dev, "ch341_control_out(%02x,%02x,%04x,%04x)\n",
	96	USB_DIR_OUT\|0x40, (int)request, (int)value, (int)index);
6ce76104 FK	97
	98	r = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request,
	99	USB_TYPE_VENDOR \| USB_RECIP_DEVICE \| USB_DIR_OUT,
	100	value, index, NULL, 0, DEFAULT_TIMEOUT);
	101
	102	return r;
	103	}
	104
	105	static int ch341_control_in(struct usb_device *dev,
	106	u8 request, u16 value, u16 index,
	107	char *buf, unsigned bufsize)
	108	{
	109	int r;
79cbeeaf GKH	110
	111	dev_dbg(&dev->dev, "ch341_control_in(%02x,%02x,%04x,%04x,%p,%u)\n",
	112	USB_DIR_IN\|0x40, (int)request, (int)value, (int)index, buf,
	113	(int)bufsize);
6ce76104 FK	114
	115	r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request,
	116	USB_TYPE_VENDOR \| USB_RECIP_DEVICE \| USB_DIR_IN,
	117	value, index, buf, bufsize, DEFAULT_TIMEOUT);
	118	return r;
	119	}
	120
93b6497d AB	121	static int ch341_set_baudrate(struct usb_device *dev,
93b6497d AB	122	struct ch341_private *priv)
6ce76104 FK	123	{
	124	short a, b;
	125	int r;
664d5df9 WC	126	unsigned long factor;
664d5df9 WC	127	short divisor;
6ce76104	128
664d5df9	129	if (!priv->baud_rate)
6ce76104	130	return -EINVAL;
664d5df9 WC	131	factor = (CH341_BAUDBASE_FACTOR / priv->baud_rate);
	132	divisor = CH341_BAUDBASE_DIVMAX;
	133
	134	while ((factor > 0xfff0) && divisor) {
	135	factor >>= 3;
	136	divisor--;
6ce76104 FK	137	}
6ce76104 FK	138
664d5df9 WC	139	if (factor > 0xfff0)
	140	return -EINVAL;
	141
	142	factor = 0x10000 - factor;
	143	a = (factor & 0xff00) \| divisor;
	144	b = factor & 0xff;
	145
6ce76104 FK	146	r = ch341_control_out(dev, 0x9a, 0x1312, a);
	147	if (!r)
	148	r = ch341_control_out(dev, 0x9a, 0x0f2c, b);
	149
	150	return r;
	151	}
	152
664d5df9	153	static int ch341_set_handshake(struct usb_device *dev, u8 control)
6ce76104	154	{
664d5df9	155	return ch341_control_out(dev, 0xa4, ~control, 0);
6ce76104 FK	156	}
6ce76104 FK	157
664d5df9	158	static int ch341_get_status(struct usb_device dev, struct ch341_private priv)
6ce76104 FK	159	{
	160	char *buffer;
	161	int r;
	162	const unsigned size = 8;
664d5df9	163	unsigned long flags;
6ce76104	164
6ce76104 FK	165	buffer = kmalloc(size, GFP_KERNEL);
	166	if (!buffer)
	167	return -ENOMEM;
	168
	169	r = ch341_control_in(dev, 0x95, 0x0706, 0, buffer, size);
c4d0f8cb	170	if (r < 0)
6ce76104 FK	171	goto out;
6ce76104 FK	172
664d5df9 WC	173	/* setup the private status if available */
	174	if (r == 2) {
	175	r = 0;
	176	spin_lock_irqsave(&priv->lock, flags);
	177	priv->line_status = (~(*buffer)) & CH341_BITS_MODEM_STAT;
	178	priv->multi_status_change = 0;
	179	spin_unlock_irqrestore(&priv->lock, flags);
	180	} else
	181	r = -EPROTO;
6ce76104 FK	182
	183	out: kfree(buffer);
	184	return r;
	185	}
	186
	187	/* -------------------------------------------------------------------------- */
	188
93b6497d	189	static int ch341_configure(struct usb_device dev, struct ch341_private priv)
6ce76104 FK	190	{
	191	char *buffer;
	192	int r;
	193	const unsigned size = 8;
	194
6ce76104 FK	195	buffer = kmalloc(size, GFP_KERNEL);
	196	if (!buffer)
	197	return -ENOMEM;
	198
	199	/* expect two bytes 0x27 0x00 */
	200	r = ch341_control_in(dev, 0x5f, 0, 0, buffer, size);
	201	if (r < 0)
	202	goto out;
	203
	204	r = ch341_control_out(dev, 0xa1, 0, 0);
	205	if (r < 0)
	206	goto out;
	207
	208	r = ch341_set_baudrate(dev, priv);
	209	if (r < 0)
	210	goto out;
	211
	212	/* expect two bytes 0x56 0x00 */
	213	r = ch341_control_in(dev, 0x95, 0x2518, 0, buffer, size);
	214	if (r < 0)
	215	goto out;
	216
	217	r = ch341_control_out(dev, 0x9a, 0x2518, 0x0050);
	218	if (r < 0)
	219	goto out;
	220
	221	/* expect 0xff 0xee */
664d5df9	222	r = ch341_get_status(dev, priv);
6ce76104 FK	223	if (r < 0)
	224	goto out;
	225
	226	r = ch341_control_out(dev, 0xa1, 0x501f, 0xd90a);
	227	if (r < 0)
	228	goto out;
	229
	230	r = ch341_set_baudrate(dev, priv);
	231	if (r < 0)
	232	goto out;
	233
664d5df9	234	r = ch341_set_handshake(dev, priv->line_control);
6ce76104 FK	235	if (r < 0)
	236	goto out;
	237
	238	/* expect 0x9f 0xee */
664d5df9	239	r = ch341_get_status(dev, priv);
6ce76104 FK	240
	241	out: kfree(buffer);
	242	return r;
	243	}
	244
	245	/* allocate private data */
	246	static int ch341_attach(struct usb_serial *serial)
	247	{
	248	struct ch341_private *priv;
	249	int r;
	250
6ce76104 FK	251	/* private data */
	252	priv = kzalloc(sizeof(struct ch341_private), GFP_KERNEL);
	253	if (!priv)
	254	return -ENOMEM;
	255
664d5df9 WC	256	spin_lock_init(&priv->lock);
664d5df9 WC	257	init_waitqueue_head(&priv->delta_msr_wait);
6ce76104	258	priv->baud_rate = DEFAULT_BAUD_RATE;
664d5df9	259	priv->line_control = CH341_BIT_RTS \| CH341_BIT_DTR;
6ce76104 FK	260
	261	r = ch341_configure(serial->dev, priv);
	262	if (r < 0)
	263	goto error;
	264
	265	usb_set_serial_port_data(serial->port[0], priv);
	266	return 0;
	267
	268	error: kfree(priv);
	269	return r;
	270	}
	271
335f8514 AC	272	static int ch341_carrier_raised(struct usb_serial_port *port)
	273	{
	274	struct ch341_private *priv = usb_get_serial_port_data(port);
	275	if (priv->line_status & CH341_BIT_DCD)
	276	return 1;
	277	return 0;
	278	}
	279
	280	static void ch341_dtr_rts(struct usb_serial_port *port, int on)
664d5df9 WC	281	{
	282	struct ch341_private *priv = usb_get_serial_port_data(port);
	283	unsigned long flags;
664d5df9	284
335f8514 AC	285	/* drop DTR and RTS */
	286	spin_lock_irqsave(&priv->lock, flags);
	287	if (on)
	288	priv->line_control \|= CH341_BIT_RTS \| CH341_BIT_DTR;
	289	else
	290	priv->line_control &= ~(CH341_BIT_RTS \| CH341_BIT_DTR);
	291	spin_unlock_irqrestore(&priv->lock, flags);
	292	ch341_set_handshake(port->serial->dev, priv->line_control);
	293	wake_up_interruptible(&priv->delta_msr_wait);
	294	}
	295
	296	static void ch341_close(struct usb_serial_port *port)
	297	{
f26788da	298	usb_serial_generic_close(port);
664d5df9	299	usb_kill_urb(port->interrupt_in_urb);
664d5df9 WC	300	}
	301
	302
6ce76104	303	/* open this device, set default parameters */
a509a7e4	304	static int ch341_open(struct tty_struct tty, struct usb_serial_port port)
6ce76104 FK	305	{
	306	struct usb_serial *serial = port->serial;
	307	struct ch341_private *priv = usb_get_serial_port_data(serial->port[0]);
	308	int r;
	309
6ce76104	310	priv->baud_rate = DEFAULT_BAUD_RATE;
6ce76104 FK	311
	312	r = ch341_configure(serial->dev, priv);
	313	if (r)
	314	goto out;
	315
664d5df9	316	r = ch341_set_handshake(serial->dev, priv->line_control);
6ce76104 FK	317	if (r)
	318	goto out;
	319
	320	r = ch341_set_baudrate(serial->dev, priv);
	321	if (r)
	322	goto out;
	323
79cbeeaf	324	dev_dbg(&port->dev, "%s - submitting interrupt urb", __func__);
664d5df9 WC	325	r = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
	326	if (r) {
	327	dev_err(&port->dev, "%s - failed submitting interrupt urb,"
	328	" error %d\n", __func__, r);
335f8514	329	ch341_close(port);
06946a66	330	goto out;
664d5df9 WC	331	}
664d5df9 WC	332
a509a7e4	333	r = usb_serial_generic_open(tty, port);
6ce76104 FK	334
	335	out: return r;
	336	}
	337
	338	/* Old_termios contains the original termios settings and
	339	* tty->termios contains the new setting to be used.
	340	*/
95da310e AC	341	static void ch341_set_termios(struct tty_struct *tty,
95da310e AC	342	struct usb_serial_port port, struct ktermios old_termios)
6ce76104 FK	343	{
6ce76104 FK	344	struct ch341_private *priv = usb_get_serial_port_data(port);
6ce76104	345	unsigned baud_rate;
664d5df9	346	unsigned long flags;
6ce76104	347
6ce76104 FK	348	baud_rate = tty_get_baud_rate(tty);
6ce76104 FK	349
664d5df9 WC	350	priv->baud_rate = baud_rate;
	351
	352	if (baud_rate) {
	353	spin_lock_irqsave(&priv->lock, flags);
	354	priv->line_control \|= (CH341_BIT_DTR \| CH341_BIT_RTS);
	355	spin_unlock_irqrestore(&priv->lock, flags);
	356	ch341_set_baudrate(port->serial->dev, priv);
	357	} else {
	358	spin_lock_irqsave(&priv->lock, flags);
	359	priv->line_control &= ~(CH341_BIT_DTR \| CH341_BIT_RTS);
	360	spin_unlock_irqrestore(&priv->lock, flags);
6ce76104 FK	361	}
6ce76104 FK	362
664d5df9	363	ch341_set_handshake(port->serial->dev, priv->line_control);
6ce76104 FK	364
	365	/* Unimplemented:
	366	* (cflag & CSIZE) : data bits [5, 8]
	367	* (cflag & PARENB) : parity {NONE, EVEN, ODD}
	368	* (cflag & CSTOPB) : stop bits [1, 2]
	369	*/
664d5df9 WC	370	}
664d5df9 WC	371
492896f0 TS	372	static void ch341_break_ctl(struct tty_struct *tty, int break_state)
	373	{
	374	const uint16_t ch341_break_reg =
	375	CH341_REG_BREAK1 \| ((uint16_t) CH341_REG_BREAK2 << 8);
	376	struct usb_serial_port *port = tty->driver_data;
	377	int r;
	378	uint16_t reg_contents;
f2b5cc83	379	uint8_t *break_reg;
492896f0	380
f2b5cc83 JH	381	break_reg = kmalloc(2, GFP_KERNEL);
	382	if (!break_reg) {
	383	dev_err(&port->dev, "%s - kmalloc failed\n", __func__);
	384	return;
	385	}
	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
	440	static void ch341_read_int_callback(struct urb *urb)
	441	{
	442	struct usb_serial_port port = (struct usb_serial_port ) urb->context;
	443	unsigned char *data = urb->transfer_buffer;
	444	unsigned int actual_length = urb->actual_length;
	445	int status;
	446
664d5df9 WC	447	switch (urb->status) {
	448	case 0:
	449	/* success */
	450	break;
	451	case -ECONNRESET:
	452	case -ENOENT:
	453	case -ESHUTDOWN:
	454	/* this urb is terminated, clean up */
79cbeeaf GKH	455	dev_dbg(&urb->dev->dev, "%s - urb shutting down with status: %d\n",
79cbeeaf GKH	456	__func__, urb->status);
664d5df9 WC	457	return;
664d5df9 WC	458	default:
79cbeeaf GKH	459	dev_dbg(&urb->dev->dev, "%s - nonzero urb status received: %d\n",
79cbeeaf GKH	460	__func__, urb->status);
664d5df9 WC	461	goto exit;
	462	}
	463
59d33f2f	464	usb_serial_debug_data(&port->dev, __func__,
664d5df9 WC	465	urb->actual_length, urb->transfer_buffer);
	466
	467	if (actual_length >= 4) {
	468	struct ch341_private *priv = usb_get_serial_port_data(port);
	469	unsigned long flags;
d14fc1a7	470	u8 prev_line_status = priv->line_status;
664d5df9 WC	471
	472	spin_lock_irqsave(&priv->lock, flags);
	473	priv->line_status = (~(data[2])) & CH341_BITS_MODEM_STAT;
	474	if ((data[1] & CH341_MULT_STAT))
	475	priv->multi_status_change = 1;
	476	spin_unlock_irqrestore(&priv->lock, flags);
d14fc1a7 LP	477
	478	if ((priv->line_status ^ prev_line_status) & CH341_BIT_DCD) {
	479	struct tty_struct *tty = tty_port_tty_get(&port->port);
	480	if (tty)
	481	usb_serial_handle_dcd_change(port, tty,
	482	priv->line_status & CH341_BIT_DCD);
	483	tty_kref_put(tty);
	484	}
	485
664d5df9 WC	486	wake_up_interruptible(&priv->delta_msr_wait);
	487	}
	488
	489	exit:
	490	status = usb_submit_urb(urb, GFP_ATOMIC);
	491	if (status)
	492	dev_err(&urb->dev->dev,
	493	"%s - usb_submit_urb failed with result %d\n",
	494	__func__, status);
	495	}
	496
	497	static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
	498	{
	499	struct ch341_private *priv = usb_get_serial_port_data(port);
	500	unsigned long flags;
	501	u8 prevstatus;
	502	u8 status;
	503	u8 changed;
	504	u8 multi_change = 0;
	505
	506	spin_lock_irqsave(&priv->lock, flags);
	507	prevstatus = priv->line_status;
	508	priv->multi_status_change = 0;
	509	spin_unlock_irqrestore(&priv->lock, flags);
	510
	511	while (!multi_change) {
	512	interruptible_sleep_on(&priv->delta_msr_wait);
	513	/* see if a signal did it */
	514	if (signal_pending(current))
	515	return -ERESTARTSYS;
	516
	517	spin_lock_irqsave(&priv->lock, flags);
	518	status = priv->line_status;
	519	multi_change = priv->multi_status_change;
	520	spin_unlock_irqrestore(&priv->lock, flags);
	521
	522	changed = prevstatus ^ status;
	523
	524	if (((arg & TIOCM_RNG) && (changed & CH341_BIT_RI)) \|\|
	525	((arg & TIOCM_DSR) && (changed & CH341_BIT_DSR)) \|\|
	526	((arg & TIOCM_CD) && (changed & CH341_BIT_DCD)) \|\|
	527	((arg & TIOCM_CTS) && (changed & CH341_BIT_CTS))) {
	528	return 0;
	529	}
	530	prevstatus = status;
	531	}
	532
	533	return 0;
	534	}
	535
00a0d0d6	536	static int ch341_ioctl(struct tty_struct *tty,
664d5df9 WC	537	unsigned int cmd, unsigned long arg)
	538	{
	539	struct usb_serial_port *port = tty->driver_data;
79cbeeaf GKH	540
79cbeeaf GKH	541	dev_dbg(&port->dev, "%s (%d) cmd = 0x%04x\n", __func__, port->number, cmd);
664d5df9 WC	542
	543	switch (cmd) {
	544	case TIOCMIWAIT:
79cbeeaf	545	dev_dbg(&port->dev, "%s (%d) TIOCMIWAIT\n", __func__, port->number);
664d5df9 WC	546	return wait_modem_info(port, arg);
	547
	548	default:
79cbeeaf	549	dev_dbg(&port->dev, "%s not supported = 0x%04x\n", __func__, cmd);
664d5df9 WC	550	break;
	551	}
	552
	553	return -ENOIOCTLCMD;
	554	}
	555
60b33c13	556	static int ch341_tiocmget(struct tty_struct *tty)
664d5df9 WC	557	{
	558	struct usb_serial_port *port = tty->driver_data;
	559	struct ch341_private *priv = usb_get_serial_port_data(port);
	560	unsigned long flags;
	561	u8 mcr;
	562	u8 status;
	563	unsigned int result;
	564
664d5df9 WC	565	spin_lock_irqsave(&priv->lock, flags);
	566	mcr = priv->line_control;
	567	status = priv->line_status;
	568	spin_unlock_irqrestore(&priv->lock, flags);
	569
	570	result = ((mcr & CH341_BIT_DTR) ? TIOCM_DTR : 0)
	571	\| ((mcr & CH341_BIT_RTS) ? TIOCM_RTS : 0)
	572	\| ((status & CH341_BIT_CTS) ? TIOCM_CTS : 0)
	573	\| ((status & CH341_BIT_DSR) ? TIOCM_DSR : 0)
	574	\| ((status & CH341_BIT_RI) ? TIOCM_RI : 0)
	575	\| ((status & CH341_BIT_DCD) ? TIOCM_CD : 0);
	576
79cbeeaf	577	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
73f59308	578
664d5df9	579	return result;
6ce76104 FK	580	}
6ce76104 FK	581
622b80cf	582	static int ch341_reset_resume(struct usb_serial *serial)
1ded7ea4	583	{
1ded7ea4 ML	584	struct ch341_private *priv;
1ded7ea4 ML	585
1ded7ea4 ML	586	priv = usb_get_serial_port_data(serial->port[0]);
1ded7ea4 ML	587
2bfd1c96 GKH	588	/* reconfigure ch341 serial port after bus-reset */
2bfd1c96 GKH	589	ch341_configure(serial->dev, priv);
1ded7ea4 ML	590
	591	return 0;
	592	}
	593
6ce76104 FK	594	static struct usb_serial_driver ch341_device = {
	595	.driver = {
	596	.owner = THIS_MODULE,
	597	.name = "ch341-uart",
	598	},
664d5df9	599	.id_table = id_table,
664d5df9 WC	600	.num_ports = 1,
664d5df9 WC	601	.open = ch341_open,
335f8514 AC	602	.dtr_rts = ch341_dtr_rts,
335f8514 AC	603	.carrier_raised = ch341_carrier_raised,
664d5df9 WC	604	.close = ch341_close,
	605	.ioctl = ch341_ioctl,
	606	.set_termios = ch341_set_termios,
492896f0	607	.break_ctl = ch341_break_ctl,
664d5df9 WC	608	.tiocmget = ch341_tiocmget,
	609	.tiocmset = ch341_tiocmset,
	610	.read_int_callback = ch341_read_int_callback,
	611	.attach = ch341_attach,
1c1eaba8	612	.reset_resume = ch341_reset_resume,
6ce76104 FK	613	};
6ce76104 FK	614
08a4f6bc AS	615	static struct usb_serial_driver * const serial_drivers[] = {
	616	&ch341_device, NULL
	617	};
	618
68e24113	619	module_usb_serial_driver(serial_drivers, id_table);
6ce76104	620
6ce76104	621	MODULE_LICENSE("GPL");