[IRDA]: TOIM3232 dongle support

	  dongles you will have to start irattach like this:

	  "irattach -d tekram".

config TOIM3232_DONGLE

	tristate "TOIM3232 IrDa dongle"

	depends on DONGLE && IRDA

	help

	  Say Y here if you want to build support for the Vishay/Temic

	  TOIM3232 and TOIM4232 based dongles.

	  To compile it as a module, choose M here.

config LITELINK_DONGLE

	tristate "Parallax LiteLink dongle"

	depends on DONGLE && IRDA

obj-$(CONFIG_MCP2120_DONGLE)	+= mcp2120-sir.o

obj-$(CONFIG_ACT200L_DONGLE)	+= act200l-sir.o

obj-$(CONFIG_MA600_DONGLE)	+= ma600-sir.o

obj-$(CONFIG_TOIM3232_DONGLE)	+= toim3232-sir.o

# The SIR helper module

sir-dev-objs := sir_dev.o sir_dongle.o sir_kthread.o

/*********************************************************************

 *

 * Filename:      toim3232-sir.c

 * Version:       1.0

 * Description:   Implementation of dongles based on the Vishay/Temic

 * 		  TOIM3232 SIR Endec chipset. Currently only the

 * 		  IRWave IR320ST-2 is tested, although it should work

 * 		  with any TOIM3232 or TOIM4232 chipset based RS232

 * 		  dongle with minimal modification.

 * 		  Based heavily on the Tekram driver (tekram.c),

 * 		  with thanks to Dag Brattli and Martin Diehl.

 * Status:        Experimental.

 * Author:        David Basden <davidb-irda@rcpt.to>

 * Created at:    Thu Feb 09 23:47:32 2006

 *

 *     Copyright (c) 2006 David Basden.

 *     Copyright (c) 1998-1999 Dag Brattli,

 *     Copyright (c) 2002 Martin Diehl,

 *     All Rights Reserved.

 *

 *     This program is free software; you can redistribute it and/or

 *     modify it under the terms of the GNU General Public License as

 *     published by the Free Software Foundation; either version 2 of

 *     the License, or (at your option) any later version.

 *

 *     Neither Dag Brattli nor University of Tromsø admit liability nor

 *     provide warranty for any of this software. This material is

 *     provided "AS-IS" and at no charge.

 *

 ********************************************************************/

/*

 * This driver has currently only been tested on the IRWave IR320ST-2

 *

 * PROTOCOL:

 *

 * The protocol for talking to the TOIM3232 is quite easy, and is

 * designed to interface with RS232 with only level convertors. The

 * BR/~D line on the chip is brought high to signal 'command mode',

 * where a command byte is sent to select the baudrate of the RS232

 * interface and the pulse length of the IRDA output. When BR/~D

 * is brought low, the dongle then changes to the selected baudrate,

 * and the RS232 interface is used for data until BR/~D is brought

 * high again. The initial speed for the TOIMx323 after RESET is

 * 9600 baud.  The baudrate for command-mode is the last selected

 * baud-rate, or 9600 after a RESET.

 *

 * The  dongle I have (below) adds some extra hardware on the front end,

 * but this is mostly directed towards pariasitic power from the RS232

 * line rather than changing very much about how to communicate with

 * the TOIM3232.

 *

 * The protocol to talk to the TOIM4232 chipset seems to be almost

 * identical to the TOIM3232 (and the 4232 datasheet is more detailed)

 * so this code will probably work on that as well, although I haven't

 * tested it on that hardware.

 *

 * Target dongle variations that might be common:

 *

 * DTR and RTS function:

 *   The data sheet for the 4232 has a sample implementation that hooks the

 *   DTR and RTS lines to the RESET and BaudRate/~Data lines of the

 *   chip (through line-converters). Given both DTR and RTS would have to

 *   be held low in normal operation, and the TOIMx232 requires +5V to

 *   signal ground, most dongle designers would almost certainly choose

 *   an implementation that kept at least one of DTR or RTS high in

 *   normal operation to provide power to the dongle, but will likely

 *   vary between designs.

 *

 * User specified command bits:

 *  There are two user-controllable output lines from the TOIMx232 that

 *  can be set low or high by setting the appropriate bits in the

 *  high-nibble of the command byte (when setting speed and pulse length).

 *  These might be used to switch on and off added hardware or extra

 *  dongle features.

 *

 *

 * Target hardware: IRWave IR320ST-2

 *

 * 	The IRWave IR320ST-2 is a simple dongle based on the Vishay/Temic

 * 	TOIM3232 SIR Endec and the Vishay/Temic TFDS4500 SIR IRDA transciever.

 * 	It uses a hex inverter and some discrete components to buffer and

 * 	line convert the RS232 down to 5V.

 *

 * 	The dongle is powered through a voltage regulator, fed by a large

 * 	capacitor. To switch the dongle on, DTR is brought high to charge

 * 	the capacitor and drive the voltage regulator. DTR isn't associated

 * 	with any control lines on the TOIM3232. Parisitic power is also taken

 * 	from the RTS, TD and RD lines when brought high, but through resistors.

 * 	When DTR is low, the circuit might lose power even with RTS high.

 *

 * 	RTS is inverted and attached to the BR/~D input pin. When RTS

 * 	is high, BR/~D is low, and the TOIM3232 is in the normal 'data' mode.

 * 	RTS is brought low, BR/~D is high, and the TOIM3232 is in 'command

 * 	mode'.

 *

 * 	For some unknown reason, the RESET line isn't actually connected

 * 	to anything. This means to reset the dongle to get it to a known

 * 	state (9600 baud) you must drop DTR and RTS low, wait for the power

 * 	capacitor to discharge, and then bring DTR (and RTS for data mode)

 * 	high again, and wait for the capacitor to charge, the power supply

 * 	to stabilise, and the oscillator clock to stabilise.

 *

 * 	Fortunately, if the current baudrate is known, the chipset can

 * 	easily change speed by entering command mode without having to

 * 	reset the dongle first.

 *

 * 	Major Components:

 *

 * 	- Vishay/Temic TOIM3232 SIR Endec to change RS232 pulse timings

 * 	  to IRDA pulse timings

 * 	- 3.6864MHz crystal to drive TOIM3232 clock oscillator

 * 	- DM74lS04M Inverting Hex line buffer for RS232 input buffering

 * 	  and level conversion

 * 	- PJ2951AC 150mA voltage regulator

 * 	- Vishay/Temic TFDS4500	SIR IRDA front-end transceiver

 *

 */

#include <linux/module.h>

#include <linux/delay.h>

#include <linux/init.h>

#include <net/irda/irda.h>

#include "sir-dev.h"

MODULE_PARM(toim3232delay, "i");

MODULE_PARM_DESC(toim3232delay, "toim3232 dongle write complete delay");

static int toim3232delay = 150;	/* default is 150 ms */

#if 0

MODULE_PARM(toim3232flipdtr, "i");

MODULE_PARM_DESC(toim3232flipdtr, "toim3232 dongle invert DTR (Reset)");

static int toim3232flipdtr = 0;	/* default is DTR high to reset */

MODULE_PARM(toim3232fliptrs, "i");

MODULE_PARM_DESC(toim3232fliprts, "toim3232 dongle invert RTS (BR/D)");

static int toim3232fliprts = 0;	/* default is RTS high for baud change */

#endif

static int toim3232_open(struct sir_dev *);

static int toim3232_close(struct sir_dev *);

static int toim3232_change_speed(struct sir_dev *, unsigned);

static int toim3232_reset(struct sir_dev *);

#define TOIM3232_115200 0x00

#define TOIM3232_57600  0x01

#define TOIM3232_38400  0x02

#define TOIM3232_19200  0x03

#define TOIM3232_9600   0x06

#define TOIM3232_2400   0x0A

#define TOIM3232_PW     0x10 /* Pulse select bit */

static struct dongle_driver toim3232 = {

	.owner		= THIS_MODULE,

	.driver_name	= "Vishay TOIM3232",

	.type		= IRDA_TOIM3232_DONGLE,

	.open		= toim3232_open,

	.close		= toim3232_close,

	.reset		= toim3232_reset,

	.set_speed	= toim3232_change_speed,

};

static int __init toim3232_sir_init(void)

{

	if (toim3232delay < 1  ||  toim3232delay > 500)

		toim3232delay = 200;

	IRDA_DEBUG(1, "%s - using %d ms delay\n",

		toim3232.driver_name, toim3232delay);

	return irda_register_dongle(&toim3232);

}

static void __exit toim3232_sir_cleanup(void)

{

	irda_unregister_dongle(&toim3232);

}

static int toim3232_open(struct sir_dev *dev)

{

	struct qos_info *qos = &dev->qos;

	IRDA_DEBUG(2, "%s()\n", __FUNCTION__);

	/* Pull the lines high to start with.

	 *

	 * For the IR320ST-2, we need to charge the main supply capacitor to

	 * switch the device on. We keep DTR high throughout to do this.

	 * When RTS, TD and RD are high, they will also trickle-charge the

	 * cap. RTS is high for data transmission, and low for baud rate select.

	 * 	-- DGB

	 */

	sirdev_set_dtr_rts(dev, TRUE, TRUE);

	/* The TOI3232 supports many speeds between 1200bps and 115000bps.

	 * We really only care about those supported by the IRDA spec, but

	 * 38400 seems to be implemented in many places */

	qos->baud_rate.bits &= IR_2400|IR_9600|IR_19200|IR_38400|IR_57600|IR_115200;

	/* From the tekram driver. Not sure what a reasonable value is -- DGB */

	qos->min_turn_time.bits = 0x01; /* Needs at least 10 ms */

	irda_qos_bits_to_value(qos);

	/* irda thread waits 50 msec for power settling */

	return 0;

}

static int toim3232_close(struct sir_dev *dev)

{

	IRDA_DEBUG(2, "%s()\n", __FUNCTION__);

	/* Power off dongle */

	sirdev_set_dtr_rts(dev, FALSE, FALSE);

	return 0;

}

/*

 * Function toim3232change_speed (dev, state, speed)

 *

 *    Set the speed for the TOIM3232 based dongle. Warning, this

 *    function must be called with a process context!

 *

 *    Algorithm

 *    1. keep DTR high but clear RTS to bring into baud programming mode

 *    2. wait at least 7us to enter programming mode

 *    3. send control word to set baud rate and timing

 *    4. wait at least 1us

 *    5. bring RTS high to enter DATA mode (RS232 is passed through to transceiver)

 *    6. should take effect immediately (although probably worth waiting)

 */

#define TOIM3232_STATE_WAIT_SPEED	(SIRDEV_STATE_DONGLE_SPEED + 1)

static int toim3232_change_speed(struct sir_dev *dev, unsigned speed)

{

	unsigned state = dev->fsm.substate;

	unsigned delay = 0;

	u8 byte;

	static int ret = 0;

	IRDA_DEBUG(2, "%s()\n", __FUNCTION__);

	switch(state) {

	case SIRDEV_STATE_DONGLE_SPEED:

		/* Figure out what we are going to send as a control byte */

		switch (speed) {

		case 2400:

			byte = TOIM3232_PW|TOIM3232_2400;

			break;

		default:

			speed = 9600;

			ret = -EINVAL;

			/* fall thru */

		case 9600:

			byte = TOIM3232_PW|TOIM3232_9600;

			break;

		case 19200:

			byte = TOIM3232_PW|TOIM3232_19200;

			break;

		case 38400:

			byte = TOIM3232_PW|TOIM3232_38400;

			break;

		case 57600:

			byte = TOIM3232_PW|TOIM3232_57600;

			break;

		case 115200:

			byte = TOIM3232_115200;

			break;

		}

		/* Set DTR, Clear RTS: Go into baud programming mode */

		sirdev_set_dtr_rts(dev, TRUE, FALSE);

		/* Wait at least 7us */

		udelay(14);

		/* Write control byte */

		sirdev_raw_write(dev, &byte, 1);

		dev->speed = speed;

		state = TOIM3232_STATE_WAIT_SPEED;

		delay = toim3232delay;

		break;

	case TOIM3232_STATE_WAIT_SPEED:

		/* Have transmitted control byte * Wait for 'at least 1us' */

		udelay(14);

		/* Set DTR, Set RTS: Go into normal data mode */

		sirdev_set_dtr_rts(dev, TRUE, TRUE);

		/* Wait (TODO: check this is needed) */

		udelay(50);

		break;

	default:

		printk(KERN_ERR "%s - undefined state %d\n", __FUNCTION__, state);

		ret = -EINVAL;

		break;

	}

	dev->fsm.substate = state;

	return (delay > 0) ? delay : ret;

}

/*

 * Function toim3232reset (driver)

 *

 *      This function resets the toim3232 dongle. Warning, this function

 *      must be called with a process context!!

 *

 * What we should do is:

 * 	0. Pull RESET high

 * 	1. Wait for at least 7us

 * 	2. Pull RESET low

 * 	3. Wait for at least 7us

 * 	4. Pull BR/~D high

 * 	5. Wait for at least 7us

 * 	6. Send control byte to set baud rate

 * 	7. Wait at least 1us after stop bit

 * 	8. Pull BR/~D low

 * 	9. Should then be in data mode

 *

 * Because the IR320ST-2 doesn't have the RESET line connected for some reason,

 * we'll have to do something else.

 *

 * The default speed after a RESET is 9600, so lets try just bringing it up in

 * data mode after switching it off, waiting for the supply capacitor to

 * discharge, and then switch it back on. This isn't actually pulling RESET

 * high, but it seems to have the same effect.

 *

 * This behaviour will probably work on dongles that have the RESET line connected,

 * but if not, add a flag for the IR320ST-2, and implment the above-listed proper

 * behaviour.

 *

 * RTS is inverted and then fed to BR/~D, so to put it in programming mode, we

 * need to have pull RTS low

 */

static int toim3232_reset(struct sir_dev *dev)

{

	IRDA_DEBUG(2, "%s()\n", __FUNCTION__);

	/* Switch off both DTR and RTS to switch off dongle */

	sirdev_set_dtr_rts(dev, FALSE, FALSE);

	/* Should sleep a while. This might be evil doing it this way.*/

	set_current_state(TASK_UNINTERRUPTIBLE);

	schedule_timeout(msecs_to_jiffies(50));

	/* Set DTR, Set RTS (data mode) */

	sirdev_set_dtr_rts(dev, TRUE, TRUE);

	/* Wait at least 10 ms for power to stabilize again */

	set_current_state(TASK_UNINTERRUPTIBLE);

	schedule_timeout(msecs_to_jiffies(10));

	/* Speed should now be 9600 */

	dev->speed = 9600;

	return 0;

}

MODULE_AUTHOR("David Basden <davidb-linux@rcpt.to>");

MODULE_DESCRIPTION("Vishay/Temic TOIM3232 based dongle driver");

MODULE_LICENSE("GPL");

MODULE_ALIAS("irda-dongle-12"); /* IRDA_TOIM3232_DONGLE */

module_init(toim3232_sir_init);

module_exit(toim3232_sir_cleanup);

	IRDA_MCP2120_DONGLE      = 9,

	IRDA_ACT200L_DONGLE      = 10,

	IRDA_MA600_DONGLE        = 11,

	IRDA_TOIM3232_DONGLE     = 12,

} IRDA_DONGLE;

/* Protocol types to be used for SOCK_DGRAM */