--- /dev/null
+/*********************************************************************
+ *
+ * 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);
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