[mirror_ubuntu-artful-kernel.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_READ_VERSION 0x5F
#define CH341_REQ_WRITE_REG    0x9A
#define CH341_REQ_READ_REG     0x95
#define CH341_REQ_SERIAL_INIT  0xA1
#define CH341_REQ_MODEM_CTRL   0xA4

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

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

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

struct ch341_private {
	spinlock_t lock; /* access lock */
	unsigned baud_rate; /* set baud rate */
	u8 line_control; /* set line control value RTS/DTR */
	u8 line_status; /* active status of modem control inputs */
};

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

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

	dev_dbg(&dev->dev, "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_init_set_baudrate(struct usb_device *dev,
				   struct ch341_private *priv, unsigned ctrl)
{
	short a;
	int r;
	unsigned long factor;
	short divisor;

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

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

	if (factor > 0xfff0)
		return -EINVAL;

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

	/* 0x9c is "enable SFR_UART Control register and timer" */
	r = ch341_control_out(dev, CH341_REQ_SERIAL_INIT,
			      0x9c | (ctrl << 8), a | 0x80);

	return r;
}

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

static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
{
	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, CH341_REQ_READ_REG, 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, CH341_REQ_READ_VERSION, 0, 0, buffer, size);
	if (r < 0)
		goto out;
	dev_dbg(&dev->dev, "Chip version: 0x%02x\n", buffer[0]);

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

	/* expect two bytes 0x56 0x00 */
	r = ch341_control_in(dev, CH341_REQ_READ_REG, 0x2518, 0, buffer, size);
	if (r < 0)
		goto out;

	r = ch341_control_out(dev, CH341_REQ_WRITE_REG, 0x2518, 0x0050);
	if (r < 0)
		goto out;

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

	r = ch341_init_set_baudrate(dev, priv, 0);
	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;

	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;

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

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

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

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

	baud_rate = tty_get_baud_rate(tty);

	ctrl = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX;

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

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

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

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

		r = ch341_init_set_baudrate(port->serial->dev, priv, ctrl);
		if (r < 0 && old_termios) {
			priv->baud_rate = tty_termios_baud_rate(old_termios);
			tty_termios_copy_hw(&tty->termios, old_termios);
		}
	}

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

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

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

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

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

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

	spin_lock_irqsave(&priv->lock, flags);
	if (set & TIOCM_RTS)
		priv->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
6fde8d29	64	#define CH341_REQ_READ_VERSION 0x5F
492896f0 TS	65	#define CH341_REQ_WRITE_REG 0x9A
492896f0 TS	66	#define CH341_REQ_READ_REG 0x95
6fde8d29 AT	67	#define CH341_REQ_SERIAL_INIT 0xA1
	68	#define CH341_REQ_MODEM_CTRL 0xA4
	69
	70	#define CH341_REG_BREAK 0x05
	71	#define CH341_REG_LCR 0x18
	72	#define CH341_NBREAK_BITS 0x01
	73
	74	#define CH341_LCR_ENABLE_RX 0x80
	75	#define CH341_LCR_ENABLE_TX 0x40
	76	#define CH341_LCR_MARK_SPACE 0x20
	77	#define CH341_LCR_PAR_EVEN 0x10
	78	#define CH341_LCR_ENABLE_PAR 0x08
	79	#define CH341_LCR_STOP_BITS_2 0x04
	80	#define CH341_LCR_CS8 0x03
	81	#define CH341_LCR_CS7 0x02
	82	#define CH341_LCR_CS6 0x01
	83	#define CH341_LCR_CS5 0x00
492896f0	84
7d40d7e8	85	static const struct usb_device_id id_table[] = {
6ce76104	86	{ USB_DEVICE(0x4348, 0x5523) },
82078234	87	{ USB_DEVICE(0x1a86, 0x7523) },
d0781383	88	{ USB_DEVICE(0x1a86, 0x5523) },
6ce76104 FK	89	{ },
	90	};
	91	MODULE_DEVICE_TABLE(usb, id_table);
	92
	93	struct ch341_private {
664d5df9	94	spinlock_t lock; /* access lock */
664d5df9 WC	95	unsigned baud_rate; /* set baud rate */
	96	u8 line_control; /* set line control value RTS/DTR */
	97	u8 line_status; /* active status of modem control inputs */
6ce76104 FK	98	};
6ce76104 FK	99
aa91def4 NP	100	static void ch341_set_termios(struct tty_struct *tty,
	101	struct usb_serial_port *port,
	102	struct ktermios *old_termios);
	103
6ce76104 FK	104	static int ch341_control_out(struct usb_device *dev, u8 request,
	105	u16 value, u16 index)
	106	{
	107	int r;
79cbeeaf GKH	108
	109	dev_dbg(&dev->dev, "ch341_control_out(%02x,%02x,%04x,%04x)\n",
	110	USB_DIR_OUT\|0x40, (int)request, (int)value, (int)index);
6ce76104 FK	111
	112	r = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request,
	113	USB_TYPE_VENDOR \| USB_RECIP_DEVICE \| USB_DIR_OUT,
	114	value, index, NULL, 0, DEFAULT_TIMEOUT);
	115
	116	return r;
	117	}
	118
	119	static int ch341_control_in(struct usb_device *dev,
	120	u8 request, u16 value, u16 index,
	121	char *buf, unsigned bufsize)
	122	{
	123	int r;
79cbeeaf GKH	124
	125	dev_dbg(&dev->dev, "ch341_control_in(%02x,%02x,%04x,%04x,%p,%u)\n",
	126	USB_DIR_IN\|0x40, (int)request, (int)value, (int)index, buf,
	127	(int)bufsize);
6ce76104 FK	128
	129	r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request,
	130	USB_TYPE_VENDOR \| USB_RECIP_DEVICE \| USB_DIR_IN,
	131	value, index, buf, bufsize, DEFAULT_TIMEOUT);
	132	return r;
	133	}
	134
4e46c410 AT	135	static int ch341_init_set_baudrate(struct usb_device *dev,
4e46c410 AT	136	struct ch341_private *priv, unsigned ctrl)
6ce76104	137	{
4e46c410	138	short a;
6ce76104	139	int r;
664d5df9 WC	140	unsigned long factor;
664d5df9 WC	141	short divisor;
6ce76104	142
664d5df9	143	if (!priv->baud_rate)
6ce76104	144	return -EINVAL;
664d5df9 WC	145	factor = (CH341_BAUDBASE_FACTOR / priv->baud_rate);
	146	divisor = CH341_BAUDBASE_DIVMAX;
	147
	148	while ((factor > 0xfff0) && divisor) {
	149	factor >>= 3;
	150	divisor--;
6ce76104 FK	151	}
6ce76104 FK	152
664d5df9 WC	153	if (factor > 0xfff0)
	154	return -EINVAL;
	155
	156	factor = 0x10000 - factor;
	157	a = (factor & 0xff00) \| divisor;
664d5df9	158
4e46c410 AT	159	/* 0x9c is "enable SFR_UART Control register and timer" */
	160	r = ch341_control_out(dev, CH341_REQ_SERIAL_INIT,
	161	0x9c \| (ctrl << 8), a \| 0x80);
6ce76104 FK	162
	163	return r;
	164	}
	165
664d5df9	166	static int ch341_set_handshake(struct usb_device *dev, u8 control)
6ce76104	167	{
6fde8d29	168	return ch341_control_out(dev, CH341_REQ_MODEM_CTRL, ~control, 0);
6ce76104 FK	169	}
6ce76104 FK	170
664d5df9	171	static int ch341_get_status(struct usb_device dev, struct ch341_private priv)
6ce76104 FK	172	{
	173	char *buffer;
	174	int r;
	175	const unsigned size = 8;
664d5df9	176	unsigned long flags;
6ce76104	177
6ce76104 FK	178	buffer = kmalloc(size, GFP_KERNEL);
	179	if (!buffer)
	180	return -ENOMEM;
	181
6fde8d29	182	r = ch341_control_in(dev, CH341_REQ_READ_REG, 0x0706, 0, buffer, size);
c4d0f8cb	183	if (r < 0)
6ce76104 FK	184	goto out;
6ce76104 FK	185
664d5df9 WC	186	/* setup the private status if available */
	187	if (r == 2) {
	188	r = 0;
	189	spin_lock_irqsave(&priv->lock, flags);
	190	priv->line_status = (~(*buffer)) & CH341_BITS_MODEM_STAT;
664d5df9 WC	191	spin_unlock_irqrestore(&priv->lock, flags);
	192	} else
	193	r = -EPROTO;
6ce76104 FK	194
	195	out: kfree(buffer);
	196	return r;
	197	}
	198
	199	/* -------------------------------------------------------------------------- */
	200
93b6497d	201	static int ch341_configure(struct usb_device dev, struct ch341_private priv)
6ce76104 FK	202	{
	203	char *buffer;
	204	int r;
	205	const unsigned size = 8;
	206
6ce76104 FK	207	buffer = kmalloc(size, GFP_KERNEL);
	208	if (!buffer)
	209	return -ENOMEM;
	210
	211	/* expect two bytes 0x27 0x00 */
6fde8d29	212	r = ch341_control_in(dev, CH341_REQ_READ_VERSION, 0, 0, buffer, size);
6ce76104 FK	213	if (r < 0)
6ce76104 FK	214	goto out;
a98b6900	215	dev_dbg(&dev->dev, "Chip version: 0x%02x\n", buffer[0]);
6ce76104	216
6fde8d29	217	r = ch341_control_out(dev, CH341_REQ_SERIAL_INIT, 0, 0);
6ce76104 FK	218	if (r < 0)
	219	goto out;
	220
6ce76104	221	/* expect two bytes 0x56 0x00 */
6fde8d29	222	r = ch341_control_in(dev, CH341_REQ_READ_REG, 0x2518, 0, buffer, size);
6ce76104 FK	223	if (r < 0)
	224	goto out;
	225
6fde8d29	226	r = ch341_control_out(dev, CH341_REQ_WRITE_REG, 0x2518, 0x0050);
6ce76104 FK	227	if (r < 0)
	228	goto out;
	229
	230	/* expect 0xff 0xee */
664d5df9	231	r = ch341_get_status(dev, priv);
6ce76104 FK	232	if (r < 0)
	233	goto out;
	234
4e46c410	235	r = ch341_init_set_baudrate(dev, priv, 0);
6ce76104 FK	236	if (r < 0)
	237	goto out;
	238
664d5df9	239	r = ch341_set_handshake(dev, priv->line_control);
6ce76104 FK	240	if (r < 0)
	241	goto out;
	242
	243	/* expect 0x9f 0xee */
664d5df9	244	r = ch341_get_status(dev, priv);
6ce76104 FK	245
	246	out: kfree(buffer);
	247	return r;
	248	}
	249
456c5be5	250	static int ch341_port_probe(struct usb_serial_port *port)
6ce76104 FK	251	{
	252	struct ch341_private *priv;
	253	int r;
	254
6ce76104 FK	255	priv = kzalloc(sizeof(struct ch341_private), GFP_KERNEL);
	256	if (!priv)
	257	return -ENOMEM;
	258
664d5df9	259	spin_lock_init(&priv->lock);
6ce76104	260	priv->baud_rate = DEFAULT_BAUD_RATE;
6ce76104	261
456c5be5	262	r = ch341_configure(port->serial->dev, priv);
6ce76104 FK	263	if (r < 0)
	264	goto error;
	265
456c5be5	266	usb_set_serial_port_data(port, priv);
6ce76104 FK	267	return 0;
	268
	269	error: kfree(priv);
	270	return r;
	271	}
	272
456c5be5 JH	273	static int ch341_port_remove(struct usb_serial_port *port)
	274	{
	275	struct ch341_private *priv;
	276
	277	priv = usb_get_serial_port_data(port);
	278	kfree(priv);
	279
	280	return 0;
	281	}
	282
335f8514 AC	283	static int ch341_carrier_raised(struct usb_serial_port *port)
	284	{
	285	struct ch341_private *priv = usb_get_serial_port_data(port);
	286	if (priv->line_status & CH341_BIT_DCD)
	287	return 1;
	288	return 0;
	289	}
	290
	291	static void ch341_dtr_rts(struct usb_serial_port *port, int on)
664d5df9 WC	292	{
	293	struct ch341_private *priv = usb_get_serial_port_data(port);
	294	unsigned long flags;
664d5df9	295
335f8514 AC	296	/* drop DTR and RTS */
	297	spin_lock_irqsave(&priv->lock, flags);
	298	if (on)
	299	priv->line_control \|= CH341_BIT_RTS \| CH341_BIT_DTR;
	300	else
	301	priv->line_control &= ~(CH341_BIT_RTS \| CH341_BIT_DTR);
	302	spin_unlock_irqrestore(&priv->lock, flags);
	303	ch341_set_handshake(port->serial->dev, priv->line_control);
335f8514 AC	304	}
	305
	306	static void ch341_close(struct usb_serial_port *port)
	307	{
f26788da	308	usb_serial_generic_close(port);
664d5df9	309	usb_kill_urb(port->interrupt_in_urb);
664d5df9 WC	310	}
	311
	312
6ce76104	313	/* open this device, set default parameters */
a509a7e4	314	static int ch341_open(struct tty_struct tty, struct usb_serial_port port)
6ce76104 FK	315	{
6ce76104 FK	316	struct usb_serial *serial = port->serial;
456c5be5	317	struct ch341_private *priv = usb_get_serial_port_data(port);
6ce76104 FK	318	int r;
6ce76104 FK	319
6ce76104 FK	320	r = ch341_configure(serial->dev, priv);
	321	if (r)
	322	goto out;
	323
aa91def4 NP	324	if (tty)
aa91def4 NP	325	ch341_set_termios(tty, port, NULL);
6ce76104	326
d9a38a87	327	dev_dbg(&port->dev, "%s - submitting interrupt urb\n", __func__);
664d5df9 WC	328	r = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
664d5df9 WC	329	if (r) {
d9a38a87 JH	330	dev_err(&port->dev, "%s - failed to submit interrupt urb: %d\n",
d9a38a87 JH	331	__func__, r);
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;
4e46c410 AT	349	unsigned char ctrl;
	350	int r;
	351
	352	/* redundant changes may cause the chip to lose bytes */
	353	if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
	354	return;
6ce76104	355
6ce76104 FK	356	baud_rate = tty_get_baud_rate(tty);
6ce76104 FK	357
ba781bdf AT	358	ctrl = CH341_LCR_ENABLE_RX \| CH341_LCR_ENABLE_TX;
	359
	360	switch (C_CSIZE(tty)) {
	361	case CS5:
	362	ctrl \|= CH341_LCR_CS5;
	363	break;
	364	case CS6:
	365	ctrl \|= CH341_LCR_CS6;
	366	break;
	367	case CS7:
	368	ctrl \|= CH341_LCR_CS7;
	369	break;
	370	case CS8:
	371	ctrl \|= CH341_LCR_CS8;
	372	break;
	373	}
	374
	375	if (C_PARENB(tty)) {
	376	ctrl \|= CH341_LCR_ENABLE_PAR;
	377	if (C_PARODD(tty) == 0)
	378	ctrl \|= CH341_LCR_PAR_EVEN;
	379	if (C_CMSPAR(tty))
	380	ctrl \|= CH341_LCR_MARK_SPACE;
	381	}
664d5df9	382
ba781bdf AT	383	if (C_CSTOPB(tty))
ba781bdf AT	384	ctrl \|= CH341_LCR_STOP_BITS_2;
4e46c410	385
664d5df9	386	if (baud_rate) {
a20047f3 JH	387	priv->baud_rate = baud_rate;
a20047f3 JH	388
4e46c410 AT	389	r = ch341_init_set_baudrate(port->serial->dev, priv, ctrl);
	390	if (r < 0 && old_termios) {
	391	priv->baud_rate = tty_termios_baud_rate(old_termios);
	392	tty_termios_copy_hw(&tty->termios, old_termios);
	393	}
6ce76104 FK	394	}
6ce76104 FK	395
030ee7ae JH	396	spin_lock_irqsave(&priv->lock, flags);
	397	if (C_BAUD(tty) == B0)
	398	priv->line_control &= ~(CH341_BIT_DTR \| CH341_BIT_RTS);
	399	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
	400	priv->line_control \|= (CH341_BIT_DTR \| CH341_BIT_RTS);
	401	spin_unlock_irqrestore(&priv->lock, flags);
6ce76104	402
030ee7ae	403	ch341_set_handshake(port->serial->dev, priv->line_control);
664d5df9 WC	404	}
664d5df9 WC	405
492896f0 TS	406	static void ch341_break_ctl(struct tty_struct *tty, int break_state)
	407	{
	408	const uint16_t ch341_break_reg =
6fde8d29	409	((uint16_t) CH341_REG_LCR << 8) \| CH341_REG_BREAK;
492896f0 TS	410	struct usb_serial_port *port = tty->driver_data;
	411	int r;
	412	uint16_t reg_contents;
f2b5cc83	413	uint8_t *break_reg;
492896f0	414
f2b5cc83	415	break_reg = kmalloc(2, GFP_KERNEL);
10c642d0	416	if (!break_reg)
f2b5cc83	417	return;
f2b5cc83	418
492896f0	419	r = ch341_control_in(port->serial->dev, CH341_REQ_READ_REG,
f2b5cc83	420	ch341_break_reg, 0, break_reg, 2);
492896f0	421	if (r < 0) {
6a9b15fe JH	422	dev_err(&port->dev, "%s - USB control read error (%d)\n",
6a9b15fe JH	423	__func__, r);
f2b5cc83	424	goto out;
492896f0	425	}
79cbeeaf GKH	426	dev_dbg(&port->dev, "%s - initial ch341 break register contents - reg1: %x, reg2: %x\n",
79cbeeaf GKH	427	__func__, break_reg[0], break_reg[1]);
492896f0	428	if (break_state != 0) {
79cbeeaf	429	dev_dbg(&port->dev, "%s - Enter break state requested\n", __func__);
6fde8d29 AT	430	break_reg[0] &= ~CH341_NBREAK_BITS;
6fde8d29 AT	431	break_reg[1] &= ~CH341_LCR_ENABLE_TX;
492896f0	432	} else {
79cbeeaf	433	dev_dbg(&port->dev, "%s - Leave break state requested\n", __func__);
6fde8d29 AT	434	break_reg[0] \|= CH341_NBREAK_BITS;
6fde8d29 AT	435	break_reg[1] \|= CH341_LCR_ENABLE_TX;
492896f0	436	}
79cbeeaf GKH	437	dev_dbg(&port->dev, "%s - New ch341 break register contents - reg1: %x, reg2: %x\n",
79cbeeaf GKH	438	__func__, break_reg[0], break_reg[1]);
5be796f0	439	reg_contents = get_unaligned_le16(break_reg);
492896f0 TS	440	r = ch341_control_out(port->serial->dev, CH341_REQ_WRITE_REG,
	441	ch341_break_reg, reg_contents);
	442	if (r < 0)
6a9b15fe JH	443	dev_err(&port->dev, "%s - USB control write error (%d)\n",
6a9b15fe JH	444	__func__, r);
f2b5cc83 JH	445	out:
f2b5cc83 JH	446	kfree(break_reg);
492896f0 TS	447	}
492896f0 TS	448
20b9d177	449	static int ch341_tiocmset(struct tty_struct *tty,
664d5df9 WC	450	unsigned int set, unsigned int clear)
	451	{
	452	struct usb_serial_port *port = tty->driver_data;
	453	struct ch341_private *priv = usb_get_serial_port_data(port);
	454	unsigned long flags;
	455	u8 control;
	456
	457	spin_lock_irqsave(&priv->lock, flags);
	458	if (set & TIOCM_RTS)
	459	priv->line_control \|= CH341_BIT_RTS;
	460	if (set & TIOCM_DTR)
	461	priv->line_control \|= CH341_BIT_DTR;
	462	if (clear & TIOCM_RTS)
	463	priv->line_control &= ~CH341_BIT_RTS;
	464	if (clear & TIOCM_DTR)
	465	priv->line_control &= ~CH341_BIT_DTR;
	466	control = priv->line_control;
	467	spin_unlock_irqrestore(&priv->lock, flags);
	468
	469	return ch341_set_handshake(port->serial->dev, control);
	470	}
	471
ac035628 JH	472	static void ch341_update_line_status(struct usb_serial_port *port,
	473	unsigned char *data, size_t len)
	474	{
	475	struct ch341_private *priv = usb_get_serial_port_data(port);
b770081f	476	struct tty_struct *tty;
ac035628	477	unsigned long flags;
b770081f JH	478	u8 status;
b770081f JH	479	u8 delta;
ac035628 JH	480
	481	if (len < 4)
	482	return;
	483
b770081f JH	484	status = ~data[2] & CH341_BITS_MODEM_STAT;
b770081f JH	485
ac035628	486	spin_lock_irqsave(&priv->lock, flags);
b770081f JH	487	delta = status ^ priv->line_status;
b770081f JH	488	priv->line_status = status;
ac035628 JH	489	spin_unlock_irqrestore(&priv->lock, flags);
ac035628 JH	490
fd74b0b1 JH	491	if (data[1] & CH341_MULT_STAT)
	492	dev_dbg(&port->dev, "%s - multiple status change\n", __func__);
	493
d984fe91 JH	494	if (!delta)
	495	return;
	496
5e409a26 JH	497	if (delta & CH341_BIT_CTS)
	498	port->icount.cts++;
	499	if (delta & CH341_BIT_DSR)
	500	port->icount.dsr++;
	501	if (delta & CH341_BIT_RI)
	502	port->icount.rng++;
b770081f	503	if (delta & CH341_BIT_DCD) {
5e409a26	504	port->icount.dcd++;
b770081f JH	505	tty = tty_port_tty_get(&port->port);
b770081f JH	506	if (tty) {
ac035628	507	usb_serial_handle_dcd_change(port, tty,
b770081f JH	508	status & CH341_BIT_DCD);
	509	tty_kref_put(tty);
	510	}
ac035628 JH	511	}
	512
	513	wake_up_interruptible(&port->port.delta_msr_wait);
	514	}
	515
664d5df9 WC	516	static void ch341_read_int_callback(struct urb *urb)
664d5df9 WC	517	{
271ec2d2	518	struct usb_serial_port *port = urb->context;
664d5df9	519	unsigned char *data = urb->transfer_buffer;
271ec2d2	520	unsigned int len = urb->actual_length;
664d5df9 WC	521	int status;
664d5df9 WC	522
664d5df9 WC	523	switch (urb->status) {
	524	case 0:
	525	/* success */
	526	break;
	527	case -ECONNRESET:
	528	case -ENOENT:
	529	case -ESHUTDOWN:
	530	/* this urb is terminated, clean up */
271ec2d2	531	dev_dbg(&urb->dev->dev, "%s - urb shutting down: %d\n",
79cbeeaf	532	__func__, urb->status);
664d5df9 WC	533	return;
664d5df9 WC	534	default:
271ec2d2	535	dev_dbg(&urb->dev->dev, "%s - nonzero urb status: %d\n",
79cbeeaf	536	__func__, urb->status);
664d5df9 WC	537	goto exit;
	538	}
	539
271ec2d2 JH	540	usb_serial_debug_data(&port->dev, __func__, len, data);
271ec2d2 JH	541	ch341_update_line_status(port, data, len);
664d5df9 WC	542	exit:
664d5df9 WC	543	status = usb_submit_urb(urb, GFP_ATOMIC);
271ec2d2 JH	544	if (status) {
271ec2d2 JH	545	dev_err(&urb->dev->dev, "%s - usb_submit_urb failed: %d\n",
664d5df9	546	__func__, status);
271ec2d2	547	}
664d5df9 WC	548	}
664d5df9 WC	549
60b33c13	550	static int ch341_tiocmget(struct tty_struct *tty)
664d5df9 WC	551	{
	552	struct usb_serial_port *port = tty->driver_data;
	553	struct ch341_private *priv = usb_get_serial_port_data(port);
	554	unsigned long flags;
	555	u8 mcr;
	556	u8 status;
	557	unsigned int result;
	558
664d5df9 WC	559	spin_lock_irqsave(&priv->lock, flags);
	560	mcr = priv->line_control;
	561	status = priv->line_status;
	562	spin_unlock_irqrestore(&priv->lock, flags);
	563
	564	result = ((mcr & CH341_BIT_DTR) ? TIOCM_DTR : 0)
	565	\| ((mcr & CH341_BIT_RTS) ? TIOCM_RTS : 0)
	566	\| ((status & CH341_BIT_CTS) ? TIOCM_CTS : 0)
	567	\| ((status & CH341_BIT_DSR) ? TIOCM_DSR : 0)
	568	\| ((status & CH341_BIT_RI) ? TIOCM_RI : 0)
	569	\| ((status & CH341_BIT_DCD) ? TIOCM_CD : 0);
	570
79cbeeaf	571	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
73f59308	572
664d5df9	573	return result;
6ce76104 FK	574	}
6ce76104 FK	575
622b80cf	576	static int ch341_reset_resume(struct usb_serial *serial)
1ded7ea4	577	{
1ded7ea4 ML	578	struct ch341_private *priv;
1ded7ea4 ML	579
1ded7ea4 ML	580	priv = usb_get_serial_port_data(serial->port[0]);
1ded7ea4 ML	581
2bfd1c96 GKH	582	/* reconfigure ch341 serial port after bus-reset */
2bfd1c96 GKH	583	ch341_configure(serial->dev, priv);
1ded7ea4 ML	584
	585	return 0;
	586	}
	587
6ce76104 FK	588	static struct usb_serial_driver ch341_device = {
	589	.driver = {
	590	.owner = THIS_MODULE,
	591	.name = "ch341-uart",
	592	},
664d5df9	593	.id_table = id_table,
664d5df9 WC	594	.num_ports = 1,
664d5df9 WC	595	.open = ch341_open,
335f8514 AC	596	.dtr_rts = ch341_dtr_rts,
335f8514 AC	597	.carrier_raised = ch341_carrier_raised,
664d5df9	598	.close = ch341_close,
664d5df9	599	.set_termios = ch341_set_termios,
492896f0	600	.break_ctl = ch341_break_ctl,
664d5df9 WC	601	.tiocmget = ch341_tiocmget,
664d5df9 WC	602	.tiocmset = ch341_tiocmset,
5e409a26	603	.tiocmiwait = usb_serial_generic_tiocmiwait,
664d5df9	604	.read_int_callback = ch341_read_int_callback,
456c5be5 JH	605	.port_probe = ch341_port_probe,
456c5be5 JH	606	.port_remove = ch341_port_remove,
1c1eaba8	607	.reset_resume = ch341_reset_resume,
6ce76104 FK	608	};
6ce76104 FK	609
08a4f6bc AS	610	static struct usb_serial_driver * const serial_drivers[] = {
	611	&ch341_device, NULL
	612	};
	613
68e24113	614	module_usb_serial_driver(serial_drivers, id_table);
6ce76104	615
6ce76104	616	MODULE_LICENSE("GPL");