Initial import

1 files changed, 580 insertions, 0 deletions

diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
new file mode 100644
index 000000000..c73808f09
--- /dev/null
+++ b/drivers/usb/serial/ch341.c
@@ -0,0 +1,580 @@
+/*
+ * 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");