[mirror_ubuntu-zesty-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_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 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_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;

	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;

	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	};
6ce76104 FK	86
aa91def4 NP	87	static void ch341_set_termios(struct tty_struct *tty,
	88	struct usb_serial_port *port,
	89	struct ktermios *old_termios);
	90
6ce76104 FK	91	static int ch341_control_out(struct usb_device *dev, u8 request,
	92	u16 value, u16 index)
	93	{
	94	int r;
79cbeeaf GKH	95
	96	dev_dbg(&dev->dev, "ch341_control_out(%02x,%02x,%04x,%04x)\n",
	97	USB_DIR_OUT\|0x40, (int)request, (int)value, (int)index);
6ce76104 FK	98
	99	r = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request,
	100	USB_TYPE_VENDOR \| USB_RECIP_DEVICE \| USB_DIR_OUT,
	101	value, index, NULL, 0, DEFAULT_TIMEOUT);
	102
	103	return r;
	104	}
	105
	106	static int ch341_control_in(struct usb_device *dev,
	107	u8 request, u16 value, u16 index,
	108	char *buf, unsigned bufsize)
	109	{
	110	int r;
79cbeeaf GKH	111
	112	dev_dbg(&dev->dev, "ch341_control_in(%02x,%02x,%04x,%04x,%p,%u)\n",
	113	USB_DIR_IN\|0x40, (int)request, (int)value, (int)index, buf,
	114	(int)bufsize);
6ce76104 FK	115
	116	r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request,
	117	USB_TYPE_VENDOR \| USB_RECIP_DEVICE \| USB_DIR_IN,
	118	value, index, buf, bufsize, DEFAULT_TIMEOUT);
	119	return r;
	120	}
	121
93b6497d AB	122	static int ch341_set_baudrate(struct usb_device *dev,
93b6497d AB	123	struct ch341_private *priv)
6ce76104 FK	124	{
	125	short a, b;
	126	int r;
664d5df9 WC	127	unsigned long factor;
664d5df9 WC	128	short divisor;
6ce76104	129
664d5df9	130	if (!priv->baud_rate)
6ce76104	131	return -EINVAL;
664d5df9 WC	132	factor = (CH341_BAUDBASE_FACTOR / priv->baud_rate);
	133	divisor = CH341_BAUDBASE_DIVMAX;
	134
	135	while ((factor > 0xfff0) && divisor) {
	136	factor >>= 3;
	137	divisor--;
6ce76104 FK	138	}
6ce76104 FK	139
664d5df9 WC	140	if (factor > 0xfff0)
	141	return -EINVAL;
	142
	143	factor = 0x10000 - factor;
	144	a = (factor & 0xff00) \| divisor;
	145	b = factor & 0xff;
	146
6ce76104 FK	147	r = ch341_control_out(dev, 0x9a, 0x1312, a);
	148	if (!r)
	149	r = ch341_control_out(dev, 0x9a, 0x0f2c, b);
	150
	151	return r;
	152	}
	153
664d5df9	154	static int ch341_set_handshake(struct usb_device *dev, u8 control)
6ce76104	155	{
664d5df9	156	return ch341_control_out(dev, 0xa4, ~control, 0);
6ce76104 FK	157	}
6ce76104 FK	158
664d5df9	159	static int ch341_get_status(struct usb_device dev, struct ch341_private priv)
6ce76104 FK	160	{
	161	char *buffer;
	162	int r;
	163	const unsigned size = 8;
664d5df9	164	unsigned long flags;
6ce76104	165
6ce76104 FK	166	buffer = kmalloc(size, GFP_KERNEL);
	167	if (!buffer)
	168	return -ENOMEM;
	169
	170	r = ch341_control_in(dev, 0x95, 0x0706, 0, buffer, size);
c4d0f8cb	171	if (r < 0)
6ce76104 FK	172	goto out;
6ce76104 FK	173
664d5df9 WC	174	/* setup the private status if available */
	175	if (r == 2) {
	176	r = 0;
	177	spin_lock_irqsave(&priv->lock, flags);
	178	priv->line_status = (~(*buffer)) & CH341_BITS_MODEM_STAT;
664d5df9 WC	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
456c5be5	245	static int ch341_port_probe(struct usb_serial_port *port)
6ce76104 FK	246	{
	247	struct ch341_private *priv;
	248	int r;
	249
6ce76104 FK	250	priv = kzalloc(sizeof(struct ch341_private), GFP_KERNEL);
	251	if (!priv)
	252	return -ENOMEM;
	253
664d5df9	254	spin_lock_init(&priv->lock);
6ce76104	255	priv->baud_rate = DEFAULT_BAUD_RATE;
664d5df9	256	priv->line_control = CH341_BIT_RTS \| CH341_BIT_DTR;
6ce76104	257
456c5be5	258	r = ch341_configure(port->serial->dev, priv);
6ce76104 FK	259	if (r < 0)
	260	goto error;
	261
456c5be5	262	usb_set_serial_port_data(port, priv);
6ce76104 FK	263	return 0;
	264
	265	error: kfree(priv);
	266	return r;
	267	}
	268
456c5be5 JH	269	static int ch341_port_remove(struct usb_serial_port *port)
	270	{
	271	struct ch341_private *priv;
	272
	273	priv = usb_get_serial_port_data(port);
	274	kfree(priv);
	275
	276	return 0;
	277	}
	278
335f8514 AC	279	static int ch341_carrier_raised(struct usb_serial_port *port)
	280	{
	281	struct ch341_private *priv = usb_get_serial_port_data(port);
	282	if (priv->line_status & CH341_BIT_DCD)
	283	return 1;
	284	return 0;
	285	}
	286
	287	static void ch341_dtr_rts(struct usb_serial_port *port, int on)
664d5df9 WC	288	{
	289	struct ch341_private *priv = usb_get_serial_port_data(port);
	290	unsigned long flags;
664d5df9	291
335f8514 AC	292	/* drop DTR and RTS */
	293	spin_lock_irqsave(&priv->lock, flags);
	294	if (on)
	295	priv->line_control \|= CH341_BIT_RTS \| CH341_BIT_DTR;
	296	else
	297	priv->line_control &= ~(CH341_BIT_RTS \| CH341_BIT_DTR);
	298	spin_unlock_irqrestore(&priv->lock, flags);
	299	ch341_set_handshake(port->serial->dev, priv->line_control);
335f8514 AC	300	}
	301
	302	static void ch341_close(struct usb_serial_port *port)
	303	{
f26788da	304	usb_serial_generic_close(port);
664d5df9	305	usb_kill_urb(port->interrupt_in_urb);
664d5df9 WC	306	}
	307
	308
6ce76104	309	/* open this device, set default parameters */
a509a7e4	310	static int ch341_open(struct tty_struct tty, struct usb_serial_port port)
6ce76104 FK	311	{
6ce76104 FK	312	struct usb_serial *serial = port->serial;
456c5be5	313	struct ch341_private *priv = usb_get_serial_port_data(port);
6ce76104 FK	314	int r;
6ce76104 FK	315
6ce76104 FK	316	r = ch341_configure(serial->dev, priv);
	317	if (r)
	318	goto out;
	319
aa91def4 NP	320	if (tty)
aa91def4 NP	321	ch341_set_termios(tty, port, NULL);
6ce76104	322
d9a38a87	323	dev_dbg(&port->dev, "%s - submitting interrupt urb\n", __func__);
664d5df9 WC	324	r = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
664d5df9 WC	325	if (r) {
d9a38a87 JH	326	dev_err(&port->dev, "%s - failed to submit interrupt urb: %d\n",
d9a38a87 JH	327	__func__, r);
06946a66	328	goto out;
664d5df9 WC	329	}
664d5df9 WC	330
a509a7e4	331	r = usb_serial_generic_open(tty, port);
6ce76104 FK	332
	333	out: return r;
	334	}
	335
	336	/* Old_termios contains the original termios settings and
	337	* tty->termios contains the new setting to be used.
	338	*/
95da310e AC	339	static void ch341_set_termios(struct tty_struct *tty,
95da310e AC	340	struct usb_serial_port port, struct ktermios old_termios)
6ce76104 FK	341	{
6ce76104 FK	342	struct ch341_private *priv = usb_get_serial_port_data(port);
6ce76104	343	unsigned baud_rate;
664d5df9	344	unsigned long flags;
6ce76104	345
6ce76104 FK	346	baud_rate = tty_get_baud_rate(tty);
6ce76104 FK	347
664d5df9 WC	348	priv->baud_rate = baud_rate;
	349
	350	if (baud_rate) {
	351	spin_lock_irqsave(&priv->lock, flags);
	352	priv->line_control \|= (CH341_BIT_DTR \| CH341_BIT_RTS);
	353	spin_unlock_irqrestore(&priv->lock, flags);
	354	ch341_set_baudrate(port->serial->dev, priv);
	355	} else {
	356	spin_lock_irqsave(&priv->lock, flags);
	357	priv->line_control &= ~(CH341_BIT_DTR \| CH341_BIT_RTS);
	358	spin_unlock_irqrestore(&priv->lock, flags);
6ce76104 FK	359	}
6ce76104 FK	360
664d5df9	361	ch341_set_handshake(port->serial->dev, priv->line_control);
6ce76104 FK	362
	363	/* Unimplemented:
	364	* (cflag & CSIZE) : data bits [5, 8]
	365	* (cflag & PARENB) : parity {NONE, EVEN, ODD}
	366	* (cflag & CSTOPB) : stop bits [1, 2]
	367	*/
664d5df9 WC	368	}
664d5df9 WC	369
492896f0 TS	370	static void ch341_break_ctl(struct tty_struct *tty, int break_state)
	371	{
	372	const uint16_t ch341_break_reg =
	373	CH341_REG_BREAK1 \| ((uint16_t) CH341_REG_BREAK2 << 8);
	374	struct usb_serial_port *port = tty->driver_data;
	375	int r;
	376	uint16_t reg_contents;
f2b5cc83	377	uint8_t *break_reg;
492896f0	378
f2b5cc83	379	break_reg = kmalloc(2, GFP_KERNEL);
10c642d0	380	if (!break_reg)
f2b5cc83	381	return;
f2b5cc83	382
492896f0	383	r = ch341_control_in(port->serial->dev, CH341_REQ_READ_REG,
f2b5cc83	384	ch341_break_reg, 0, break_reg, 2);
492896f0	385	if (r < 0) {
6a9b15fe JH	386	dev_err(&port->dev, "%s - USB control read error (%d)\n",
6a9b15fe JH	387	__func__, r);
f2b5cc83	388	goto out;
492896f0	389	}
79cbeeaf GKH	390	dev_dbg(&port->dev, "%s - initial ch341 break register contents - reg1: %x, reg2: %x\n",
79cbeeaf GKH	391	__func__, break_reg[0], break_reg[1]);
492896f0	392	if (break_state != 0) {
79cbeeaf	393	dev_dbg(&port->dev, "%s - Enter break state requested\n", __func__);
492896f0 TS	394	break_reg[0] &= ~CH341_NBREAK_BITS_REG1;
	395	break_reg[1] &= ~CH341_NBREAK_BITS_REG2;
	396	} else {
79cbeeaf	397	dev_dbg(&port->dev, "%s - Leave break state requested\n", __func__);
492896f0 TS	398	break_reg[0] \|= CH341_NBREAK_BITS_REG1;
	399	break_reg[1] \|= CH341_NBREAK_BITS_REG2;
	400	}
79cbeeaf GKH	401	dev_dbg(&port->dev, "%s - New ch341 break register contents - reg1: %x, reg2: %x\n",
79cbeeaf GKH	402	__func__, break_reg[0], break_reg[1]);
5be796f0	403	reg_contents = get_unaligned_le16(break_reg);
492896f0 TS	404	r = ch341_control_out(port->serial->dev, CH341_REQ_WRITE_REG,
	405	ch341_break_reg, reg_contents);
	406	if (r < 0)
6a9b15fe JH	407	dev_err(&port->dev, "%s - USB control write error (%d)\n",
6a9b15fe JH	408	__func__, r);
f2b5cc83 JH	409	out:
f2b5cc83 JH	410	kfree(break_reg);
492896f0 TS	411	}
492896f0 TS	412
20b9d177	413	static int ch341_tiocmset(struct tty_struct *tty,
664d5df9 WC	414	unsigned int set, unsigned int clear)
	415	{
	416	struct usb_serial_port *port = tty->driver_data;
	417	struct ch341_private *priv = usb_get_serial_port_data(port);
	418	unsigned long flags;
	419	u8 control;
	420
	421	spin_lock_irqsave(&priv->lock, flags);
	422	if (set & TIOCM_RTS)
	423	priv->line_control \|= CH341_BIT_RTS;
	424	if (set & TIOCM_DTR)
	425	priv->line_control \|= CH341_BIT_DTR;
	426	if (clear & TIOCM_RTS)
	427	priv->line_control &= ~CH341_BIT_RTS;
	428	if (clear & TIOCM_DTR)
	429	priv->line_control &= ~CH341_BIT_DTR;
	430	control = priv->line_control;
	431	spin_unlock_irqrestore(&priv->lock, flags);
	432
	433	return ch341_set_handshake(port->serial->dev, control);
	434	}
	435
ac035628 JH	436	static void ch341_update_line_status(struct usb_serial_port *port,
	437	unsigned char *data, size_t len)
	438	{
	439	struct ch341_private *priv = usb_get_serial_port_data(port);
b770081f	440	struct tty_struct *tty;
ac035628	441	unsigned long flags;
b770081f JH	442	u8 status;
b770081f JH	443	u8 delta;
ac035628 JH	444
	445	if (len < 4)
	446	return;
	447
b770081f JH	448	status = ~data[2] & CH341_BITS_MODEM_STAT;
b770081f JH	449
ac035628	450	spin_lock_irqsave(&priv->lock, flags);
b770081f JH	451	delta = status ^ priv->line_status;
b770081f JH	452	priv->line_status = status;
ac035628 JH	453	spin_unlock_irqrestore(&priv->lock, flags);
ac035628 JH	454
fd74b0b1 JH	455	if (data[1] & CH341_MULT_STAT)
	456	dev_dbg(&port->dev, "%s - multiple status change\n", __func__);
	457
d984fe91 JH	458	if (!delta)
	459	return;
	460
5e409a26 JH	461	if (delta & CH341_BIT_CTS)
	462	port->icount.cts++;
	463	if (delta & CH341_BIT_DSR)
	464	port->icount.dsr++;
	465	if (delta & CH341_BIT_RI)
	466	port->icount.rng++;
b770081f	467	if (delta & CH341_BIT_DCD) {
5e409a26	468	port->icount.dcd++;
b770081f JH	469	tty = tty_port_tty_get(&port->port);
b770081f JH	470	if (tty) {
ac035628	471	usb_serial_handle_dcd_change(port, tty,
b770081f JH	472	status & CH341_BIT_DCD);
	473	tty_kref_put(tty);
	474	}
ac035628 JH	475	}
	476
	477	wake_up_interruptible(&port->port.delta_msr_wait);
	478	}
	479
664d5df9 WC	480	static void ch341_read_int_callback(struct urb *urb)
664d5df9 WC	481	{
271ec2d2	482	struct usb_serial_port *port = urb->context;
664d5df9	483	unsigned char *data = urb->transfer_buffer;
271ec2d2	484	unsigned int len = urb->actual_length;
664d5df9 WC	485	int status;
664d5df9 WC	486
664d5df9 WC	487	switch (urb->status) {
	488	case 0:
	489	/* success */
	490	break;
	491	case -ECONNRESET:
	492	case -ENOENT:
	493	case -ESHUTDOWN:
	494	/* this urb is terminated, clean up */
271ec2d2	495	dev_dbg(&urb->dev->dev, "%s - urb shutting down: %d\n",
79cbeeaf	496	__func__, urb->status);
664d5df9 WC	497	return;
664d5df9 WC	498	default:
271ec2d2	499	dev_dbg(&urb->dev->dev, "%s - nonzero urb status: %d\n",
79cbeeaf	500	__func__, urb->status);
664d5df9 WC	501	goto exit;
	502	}
	503
271ec2d2 JH	504	usb_serial_debug_data(&port->dev, __func__, len, data);
271ec2d2 JH	505	ch341_update_line_status(port, data, len);
664d5df9 WC	506	exit:
664d5df9 WC	507	status = usb_submit_urb(urb, GFP_ATOMIC);
271ec2d2 JH	508	if (status) {
271ec2d2 JH	509	dev_err(&urb->dev->dev, "%s - usb_submit_urb failed: %d\n",
664d5df9	510	__func__, status);
271ec2d2	511	}
664d5df9 WC	512	}
664d5df9 WC	513
60b33c13	514	static int ch341_tiocmget(struct tty_struct *tty)
664d5df9 WC	515	{
	516	struct usb_serial_port *port = tty->driver_data;
	517	struct ch341_private *priv = usb_get_serial_port_data(port);
	518	unsigned long flags;
	519	u8 mcr;
	520	u8 status;
	521	unsigned int result;
	522
664d5df9 WC	523	spin_lock_irqsave(&priv->lock, flags);
	524	mcr = priv->line_control;
	525	status = priv->line_status;
	526	spin_unlock_irqrestore(&priv->lock, flags);
	527
	528	result = ((mcr & CH341_BIT_DTR) ? TIOCM_DTR : 0)
	529	\| ((mcr & CH341_BIT_RTS) ? TIOCM_RTS : 0)
	530	\| ((status & CH341_BIT_CTS) ? TIOCM_CTS : 0)
	531	\| ((status & CH341_BIT_DSR) ? TIOCM_DSR : 0)
	532	\| ((status & CH341_BIT_RI) ? TIOCM_RI : 0)
	533	\| ((status & CH341_BIT_DCD) ? TIOCM_CD : 0);
	534
79cbeeaf	535	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
73f59308	536
664d5df9	537	return result;
6ce76104 FK	538	}
6ce76104 FK	539
622b80cf	540	static int ch341_reset_resume(struct usb_serial *serial)
1ded7ea4	541	{
1ded7ea4 ML	542	struct ch341_private *priv;
1ded7ea4 ML	543
1ded7ea4 ML	544	priv = usb_get_serial_port_data(serial->port[0]);
1ded7ea4 ML	545
2bfd1c96 GKH	546	/* reconfigure ch341 serial port after bus-reset */
2bfd1c96 GKH	547	ch341_configure(serial->dev, priv);
1ded7ea4 ML	548
	549	return 0;
	550	}
	551
6ce76104 FK	552	static struct usb_serial_driver ch341_device = {
	553	.driver = {
	554	.owner = THIS_MODULE,
	555	.name = "ch341-uart",
	556	},
664d5df9	557	.id_table = id_table,
664d5df9 WC	558	.num_ports = 1,
664d5df9 WC	559	.open = ch341_open,
335f8514 AC	560	.dtr_rts = ch341_dtr_rts,
335f8514 AC	561	.carrier_raised = ch341_carrier_raised,
664d5df9	562	.close = ch341_close,
664d5df9	563	.set_termios = ch341_set_termios,
492896f0	564	.break_ctl = ch341_break_ctl,
664d5df9 WC	565	.tiocmget = ch341_tiocmget,
664d5df9 WC	566	.tiocmset = ch341_tiocmset,
5e409a26	567	.tiocmiwait = usb_serial_generic_tiocmiwait,
664d5df9	568	.read_int_callback = ch341_read_int_callback,
456c5be5 JH	569	.port_probe = ch341_port_probe,
456c5be5 JH	570	.port_remove = ch341_port_remove,
1c1eaba8	571	.reset_resume = ch341_reset_resume,
6ce76104 FK	572	};
6ce76104 FK	573
08a4f6bc AS	574	static struct usb_serial_driver * const serial_drivers[] = {
	575	&ch341_device, NULL
	576	};
	577
68e24113	578	module_usb_serial_driver(serial_drivers, id_table);
6ce76104	579
6ce76104	580	MODULE_LICENSE("GPL");