diff options
Diffstat (limited to 'drivers/net/irda/toim3232-sir.c')
| -rw-r--r-- | drivers/net/irda/toim3232-sir.c | 375 |
1 files changed, 375 insertions, 0 deletions
diff --git a/drivers/net/irda/toim3232-sir.c b/drivers/net/irda/toim3232-sir.c new file mode 100644 index 000000000000..aa1a9b0ed83e --- /dev/null +++ b/drivers/net/irda/toim3232-sir.c @@ -0,0 +1,375 @@ +/********************************************************************* + * + * 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" + +static int toim3232delay = 150; /* default is 150 ms */ +module_param(toim3232delay, int, 0); +MODULE_PARM_DESC(toim3232delay, "toim3232 dongle write complete delay"); + +#if 0 +static int toim3232flipdtr = 0; /* default is DTR high to reset */ +module_param(toim3232flipdtr, int, 0); +MODULE_PARM_DESC(toim3232flipdtr, "toim3232 dongle invert DTR (Reset)"); + +static int toim3232fliprts = 0; /* default is RTS high for baud change */ +module_param(toim3232fliptrs, int, 0); +MODULE_PARM_DESC(toim3232fliprts, "toim3232 dongle invert RTS (BR/D)"); +#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); |