cp2101.c

linux-2.6.15.6

/*
 * Silicon Laboratories CP2101/CP2102 USB to RS232 serial adaptor driver
 *
 * Copyright (C) 2005 Craig Shelley ([e-mail])
 *
 *	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.
 *
 * Support to set flow control line levels using TIOCMGET and TIOCMSET
 * thanks to Karl Hiramoto [e-mail]. RTSCTS hardware flow
 * control thanks to Munir Nassar [e-mail]
 *
 * Outstanding Issues:
 *  Buffers are not flushed when the port is opened.
 *  Multiple calls to write() may fail with "Resource temporarily unavailable"
 *
 */

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/usb.h>
#include <asm/uaccess.h>
#include "usb-serial.h"

/*
 * Version Information
 */
#define DRIVER_VERSION "v0.05"
#define DRIVER_DESC "Silicon Labs CP2101/CP2102 RS232 serial adaptor driver"

/*
 * Function Prototypes
 */
static int cp2101_open(struct usb_serial_port*, struct file*);
static void cp2101_cleanup(struct usb_serial_port*);
static void cp2101_close(struct usb_serial_port*, struct file*);
static void cp2101_get_termios(struct usb_serial_port*);
static void cp2101_set_termios(struct usb_serial_port*, struct termios*);
static int cp2101_tiocmget (struct usb_serial_port *, struct file *);
static int cp2101_tiocmset (struct usb_serial_port *, struct file *,
		unsigned int, unsigned int);
static void cp2101_break_ctl(struct usb_serial_port*, int);
static int cp2101_startup (struct usb_serial *);
static void cp2101_shutdown(struct usb_serial*);


static int debug;

static struct usb_device_id id_table [] = {
	{ USB_DEVICE(0x0FCF, 0x1003) }, /* Dynastream ANT development board */
	{ USB_DEVICE(0x10C4, 0xEA60) },	/* Silicon Labs factory default */
	{ USB_DEVICE(0x10C4, 0x80CA) },	/* Degree Controls Inc */
	{ USB_DEVICE(0x10C4, 0x80F6) }, /* Suunto sports instrument */
	{ USB_DEVICE(0x10A6, 0xAA26) }, /* Knock-off DCU-11 cable */
	{ USB_DEVICE(0x10AB, 0x10C5) },	/* Siemens MC60 Cable */
	{ USB_DEVICE(0x16D6, 0x0001) }, /* Jablotron serial interface */
	{ } /* Terminating Entry */
};

MODULE_DEVICE_TABLE (usb, id_table);

static struct usb_driver cp2101_driver = {
	.owner		= THIS_MODULE,
	.name		= "cp2101",
	.probe		= usb_serial_probe,
	.disconnect	= usb_serial_disconnect,
	.id_table	= id_table,
};

static struct usb_serial_driver cp2101_device = {
	.driver = {
		.owner =	THIS_MODULE,
		.name = 	"cp2101",
	},
	.id_table		= id_table,
	.num_interrupt_in	= 0,
	.num_bulk_in		= 0,
	.num_bulk_out		= 0,
	.num_ports		= 1,
	.open			= cp2101_open,
	.close			= cp2101_close,
	.break_ctl		= cp2101_break_ctl,
	.set_termios		= cp2101_set_termios,
	.tiocmget 		= cp2101_tiocmget,
	.tiocmset		= cp2101_tiocmset,
	.attach			= cp2101_startup,
	.shutdown		= cp2101_shutdown,
};

/* Config request types */
#define REQTYPE_HOST_TO_DEVICE	0x41
#define REQTYPE_DEVICE_TO_HOST	0xc1

/* Config SET requests. To GET, add 1 to the request number */
#define CP2101_UART 		0x00	/* Enable / Disable */
#define CP2101_BAUDRATE		0x01	/* (BAUD_RATE_GEN_FREQ / baudrate) */
#define CP2101_BITS		0x03	/* 0x(0)(databits)(parity)(stopbits) */
#define CP2101_BREAK		0x05	/* On / Off */
#define CP2101_CONTROL		0x07	/* Flow control line states */
#define CP2101_MODEMCTL		0x13	/* Modem controls */
#define CP2101_CONFIG_6		0x19	/* 6 bytes of config data ??? */

/* CP2101_UART */
#define UART_ENABLE		0x0001
#define UART_DISABLE		0x0000

/* CP2101_BAUDRATE */
#define BAUD_RATE_GEN_FREQ	0x384000

/* CP2101_BITS */
#define BITS_DATA_MASK		0X0f00
#define BITS_DATA_5		0X0500
#define BITS_DATA_6		0X0600
#define BITS_DATA_7		0X0700
#define BITS_DATA_8		0X0800
#define BITS_DATA_9		0X0900

#define BITS_PARITY_MASK	0x00f0
#define BITS_PARITY_NONE	0x0000
#define BITS_PARITY_ODD		0x0010
#define BITS_PARITY_EVEN	0x0020
#define BITS_PARITY_MARK	0x0030
#define BITS_PARITY_SPACE	0x0040

#define BITS_STOP_MASK		0x000f
#define BITS_STOP_1		0x0000
#define BITS_STOP_1_5		0x0001
#define BITS_STOP_2		0x0002

/* CP2101_BREAK */
#define BREAK_ON		0x0000
#define BREAK_OFF		0x0001

/* CP2101_CONTROL */
#define CONTROL_DTR		0x0001
#define CONTROL_RTS		0x0002
#define CONTROL_CTS		0x0010
#define CONTROL_DSR		0x0020
#define CONTROL_RING		0x0040
#define CONTROL_DCD		0x0080
#define CONTROL_WRITE_DTR	0x0100
#define CONTROL_WRITE_RTS	0x0200

/*
 * cp2101_get_config
 * Reads from the CP2101 configuration registers
 * 'size' is specified in bytes.
 * 'data' is a pointer to a pre-allocated array of integers large
 * enough to hold 'size' bytes (with 4 bytes to each integer)
 */
static int cp2101_get_config(struct usb_serial_port* port, u8 request,
		unsigned int *data, int size)
{
	struct usb_serial *serial = port->serial;
	u32 *buf;
	int result, i, length;

	/* Number of integers required to contain the array */
	length = (((size - 1) | 3) + 1)/4;

	buf = kmalloc (length * sizeof(u32), GFP_KERNEL);
	memset(buf, 0, length * sizeof(u32));

	if (!buf) {
		dev_err(&port->dev, "%s - out of memory.\n", __FUNCTION__);
		return -ENOMEM;
	}

	/* For get requests, the request number must be incremented */
	request++;

	/* Issue the request, attempting to read 'size' bytes */
	result = usb_control_msg (serial->dev,usb_rcvctrlpipe (serial->dev, 0),
				request, REQTYPE_DEVICE_TO_HOST, 0x0000,
				0, buf, size, 300);

	/* Convert data into an array of integers */
	for (i=0; i<length; i++)
		data[i] = le32_to_cpu(buf[i]);

	kfree(buf);

	if (result != size) {
		dev_err(&port->dev, "%s - Unable to send config request, "
				"request=0x%x size=%d result=%d\n",
				__FUNCTION__, request, size, result);
		return -EPROTO;
	}

	return 0;
}

/*
 * cp2101_set_config
 * Writes to the CP2101 configuration registers
 * Values less than 16 bits wide are sent directly
 * 'size' is specified in bytes.
 */
static int cp2101_set_config(struct usb_serial_port* port, u8 request,
		unsigned int *data, int size)
{
	struct usb_serial *serial = port->serial;
	u32 *buf;
	int result, i, length;

	/* Number of integers required to contain the array */
	length = (((size - 1) | 3) + 1)/4;

	buf = kmalloc(length * sizeof(u32), GFP_KERNEL);
	if (!buf) {
		dev_err(&port->dev, "%s - out of memory.\n",
				__FUNCTION__);
		return -ENOMEM;
	}

	/* Array of integers into bytes */
	for (i = 0; i < length; i++)
		buf[i] = cpu_to_le32(data[i]);

	if (size > 2) {
		result = usb_control_msg (serial->dev,
				usb_sndctrlpipe(serial->dev, 0),
				request, REQTYPE_HOST_TO_DEVICE, 0x0000,
				0, buf, size, 300);
	} else {
		result = usb_control_msg (serial->dev,
				usb_sndctrlpipe(serial->dev, 0),
				request, REQTYPE_HOST_TO_DEVICE, data[0],
				0, NULL, 0, 300);
	}

	kfree(buf);

	if ((size > 2 && result != size) || result < 0) {
		dev_err(&port->dev, "%s - Unable to send request, "
				"request=0x%x size=%d result=%d\n",
				__FUNCTION__, request, size, result);
		return -EPROTO;
	}

	/* Single data value */
	result = usb_control_msg (serial->dev,
			usb_sndctrlpipe(serial->dev, 0),
			request, REQTYPE_HOST_TO_DEVICE, data[0],
			0, NULL, 0, 300);
	return 0;
}

/*
 * cp2101_set_config_single
 * Convenience function for calling cp2101_set_config on single data values
 * without requiring an integer pointer
 */
static inline int cp2101_set_config_single(struct usb_serial_port* port,
		u8 request, unsigned int data)
{
	return cp2101_set_config(port, request, &data, 2);
}

static int cp2101_open (struct usb_serial_port *port, struct file *filp)
{
	struct usb_serial *serial = port->serial;
	int result;

	dbg("%s - port %d", __FUNCTION__, port->number);

	if (cp2101_set_config_single(port, CP2101_UART, UART_ENABLE)) {
		dev_err(&port->dev, "%s - Unable to enable UART\n",
				__FUNCTION__);
		return -EPROTO;
	}

	/* Start reading from the device */
	usb_fill_bulk_urb (port->read_urb, serial->dev,
			usb_rcvbulkpipe(serial->dev,
			port->bulk_in_endpointAddress),
			port->read_urb->transfer_buffer,
			port->read_urb->transfer_buffer_length,
			serial->type->read_bulk_callback,
			port);
	result = usb_submit_urb(port->read_urb, GFP_KERNEL);
	if (result) {
		dev_err(&port->dev, "%s - failed resubmitting read urb, "
				"error %d\n", __FUNCTION__, result);
		return result;
	}

	/* Configure the termios structure */
	cp2101_get_termios(port);

	/* Set the DTR and RTS pins low */
	cp2101_tiocmset(port, NULL, TIOCM_DTR | TIOCM_RTS, 0);

	return 0;
}

static void cp2101_cleanup (struct usb_serial_port *port)
{
	struct usb_serial *serial = port->serial;

	dbg("%s - port %d", __FUNCTION__, port->number);

	if (serial->dev) {
		/* shutdown any bulk reads that might be going on */
		if (serial->num_bulk_out)
			usb_kill_urb(port->write_urb);
		if (serial->num_bulk_in)
			usb_kill_urb(port->read_urb);
	}
}

static void cp2101_close (struct usb_serial_port *port, struct file * filp)
{
	dbg("%s - port %d", __FUNCTION__, port->number);

	/* shutdown our urbs */
	dbg("%s - shutting down urbs", __FUNCTION__);
	usb_kill_urb(port->write_urb);
	usb_kill_urb(port->read_urb);

	cp2101_set_config_single(port, CP2101_UART, UART_DISABLE);
}

/*
 * cp2101_get_termios
 * Reads the baud rate, data bits, parity, stop bits and flow control mode
 * from the device, corrects any unsupported values, and configures the
 * termios structure to reflect the state of the device
 */
static void cp2101_get_termios (struct usb_serial_port *port)
{
	unsigned int cflag, modem_ctl[4];
	int baud;
	int bits;

	dbg("%s - port %d", __FUNCTION__, port->number);

	if ((!port->tty) || (!port->tty->termios)) {
		dbg("%s - no tty structures", __FUNCTION__);
		return;
	}
	cflag = port->tty->termios->c_cflag;

	cp2101_get_config(port, CP2101_BAUDRATE, &baud, 2);
	/* Convert to baudrate */
	if (baud)
		baud = BAUD_RATE_GEN_FREQ / baud;

	dbg("%s - baud rate = %d", __FUNCTION__, baud);
	cflag &= ~CBAUD;
	switch (baud) {
		/*
		 * The baud rates which are commented out below
		 * appear to be supported by the device
		 * but are non-standard
		 */
		case 600:	cflag |= B600;		break;
		case 1200:	cflag |= B1200;		break;
		case 1800:	cflag |= B1800;		break;
		case 2400:	cflag |= B2400;		break;
		case 4800:	cflag |= B4800;		break;
		/*case 7200:	cflag |= B7200;		break;*/
		case 9600:	cflag |= B9600;		break;
		/*case 14400:	cflag |= B14400;	break;*/
		case 19200:	cflag |= B19200;	break;
		/*case 28800:	cflag |= B28800;	break;*/
		case 38400:	cflag |= B38400;	break;
		/*case 55854:	cflag |= B55054;	break;*/
		case 57600:	cflag |= B57600;	break;
		case 115200:	cflag |= B115200;	break;
		/*case 127117:	cflag |= B127117;	break;*/
		case 230400:	cflag |= B230400;	break;
		case 460800:	cflag |= B460800;	break;
		case 921600:	cflag |= B921600;	break;
		/*case 3686400:	cflag |= B3686400;	break;*/
		default:
			dbg("%s - Baud rate is not supported, "
					"using 9600 baud", __FUNCTION__);
			cflag |= B9600;
			cp2101_set_config_single(port, CP2101_BAUDRATE,
					(BAUD_RATE_GEN_FREQ/9600));
			break;
	}

	cp2101_get_config(port, CP2101_BITS, &bits, 2);
	cflag &= ~CSIZE;