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Diffstat (limited to '')
| -rw-r--r-- | drivers/input/joystick/twidjoy.c | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/drivers/input/joystick/twidjoy.c b/drivers/input/joystick/twidjoy.c new file mode 100644 index 0000000000..9b6792ac27 --- /dev/null +++ b/drivers/input/joystick/twidjoy.c @@ -0,0 +1,244 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2001 Arndt Schoenewald + * Copyright (c) 2000-2001 Vojtech Pavlik + * Copyright (c) 2000 Mark Fletcher + * + * Sponsored by Quelltext AG (http://www.quelltext-ag.de), Dortmund, Germany + */ + +/* + * Driver to use Handykey's Twiddler (the first edition, i.e. the one with + * the RS232 interface) as a joystick under Linux + * + * The Twiddler is a one-handed chording keyboard featuring twelve buttons on + * the front, six buttons on the top, and a built-in tilt sensor. The buttons + * on the front, which are grouped as four rows of three buttons, are pressed + * by the four fingers (this implies only one button per row can be held down + * at the same time) and the buttons on the top are for the thumb. The tilt + * sensor delivers X and Y axis data depending on how the Twiddler is held. + * Additional information can be found at http://www.handykey.com. + * + * This driver does not use the Twiddler for its intended purpose, i.e. as + * a chording keyboard, but as a joystick: pressing and releasing a button + * immediately sends a corresponding button event, and tilting it generates + * corresponding ABS_X and ABS_Y events. This turns the Twiddler into a game + * controller with amazing 18 buttons :-) + * + * Note: The Twiddler2 (the successor of the Twiddler that connects directly + * to the PS/2 keyboard and mouse ports) is NOT supported by this driver! + * + * For questions or feedback regarding this driver module please contact: + * Arndt Schoenewald <arndt@quelltext.com> + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/input.h> +#include <linux/serio.h> + +#define DRIVER_DESC "Handykey Twiddler keyboard as a joystick driver" + +MODULE_DESCRIPTION(DRIVER_DESC); +MODULE_LICENSE("GPL"); + +/* + * Constants. + */ + +#define TWIDJOY_MAX_LENGTH 5 + +static struct twidjoy_button_spec { + int bitshift; + int bitmask; + int buttons[3]; +} +twidjoy_buttons[] = { + { 0, 3, { BTN_A, BTN_B, BTN_C } }, + { 2, 3, { BTN_X, BTN_Y, BTN_Z } }, + { 4, 3, { BTN_TL, BTN_TR, BTN_TR2 } }, + { 6, 3, { BTN_SELECT, BTN_START, BTN_MODE } }, + { 8, 1, { BTN_BASE5 } }, + { 9, 1, { BTN_BASE } }, + { 10, 1, { BTN_BASE3 } }, + { 11, 1, { BTN_BASE4 } }, + { 12, 1, { BTN_BASE2 } }, + { 13, 1, { BTN_BASE6 } }, + { 0, 0, { 0 } } +}; + +/* + * Per-Twiddler data. + */ + +struct twidjoy { + struct input_dev *dev; + int idx; + unsigned char data[TWIDJOY_MAX_LENGTH]; + char phys[32]; +}; + +/* + * twidjoy_process_packet() decodes packets the driver receives from the + * Twiddler. It updates the data accordingly. + */ + +static void twidjoy_process_packet(struct twidjoy *twidjoy) +{ + struct input_dev *dev = twidjoy->dev; + unsigned char *data = twidjoy->data; + struct twidjoy_button_spec *bp; + int button_bits, abs_x, abs_y; + + button_bits = ((data[1] & 0x7f) << 7) | (data[0] & 0x7f); + + for (bp = twidjoy_buttons; bp->bitmask; bp++) { + int value = (button_bits & (bp->bitmask << bp->bitshift)) >> bp->bitshift; + int i; + + for (i = 0; i < bp->bitmask; i++) + input_report_key(dev, bp->buttons[i], i+1 == value); + } + + abs_x = ((data[4] & 0x07) << 5) | ((data[3] & 0x7C) >> 2); + if (data[4] & 0x08) abs_x -= 256; + + abs_y = ((data[3] & 0x01) << 7) | ((data[2] & 0x7F) >> 0); + if (data[3] & 0x02) abs_y -= 256; + + input_report_abs(dev, ABS_X, -abs_x); + input_report_abs(dev, ABS_Y, +abs_y); + + input_sync(dev); +} + +/* + * twidjoy_interrupt() is called by the low level driver when characters + * are ready for us. We then buffer them for further processing, or call the + * packet processing routine. + */ + +static irqreturn_t twidjoy_interrupt(struct serio *serio, unsigned char data, unsigned int flags) +{ + struct twidjoy *twidjoy = serio_get_drvdata(serio); + + /* All Twiddler packets are 5 bytes. The fact that the first byte + * has a MSB of 0 and all other bytes have a MSB of 1 can be used + * to check and regain sync. */ + + if ((data & 0x80) == 0) + twidjoy->idx = 0; /* this byte starts a new packet */ + else if (twidjoy->idx == 0) + return IRQ_HANDLED; /* wrong MSB -- ignore this byte */ + + if (twidjoy->idx < TWIDJOY_MAX_LENGTH) + twidjoy->data[twidjoy->idx++] = data; + + if (twidjoy->idx == TWIDJOY_MAX_LENGTH) { + twidjoy_process_packet(twidjoy); + twidjoy->idx = 0; + } + + return IRQ_HANDLED; +} + +/* + * twidjoy_disconnect() is the opposite of twidjoy_connect() + */ + +static void twidjoy_disconnect(struct serio *serio) +{ + struct twidjoy *twidjoy = serio_get_drvdata(serio); + + serio_close(serio); + serio_set_drvdata(serio, NULL); + input_unregister_device(twidjoy->dev); + kfree(twidjoy); +} + +/* + * twidjoy_connect() is the routine that is called when someone adds a + * new serio device. It looks for the Twiddler, and if found, registers + * it as an input device. + */ + +static int twidjoy_connect(struct serio *serio, struct serio_driver *drv) +{ + struct twidjoy_button_spec *bp; + struct twidjoy *twidjoy; + struct input_dev *input_dev; + int err = -ENOMEM; + int i; + + twidjoy = kzalloc(sizeof(struct twidjoy), GFP_KERNEL); + input_dev = input_allocate_device(); + if (!twidjoy || !input_dev) + goto fail1; + + twidjoy->dev = input_dev; + snprintf(twidjoy->phys, sizeof(twidjoy->phys), "%s/input0", serio->phys); + + input_dev->name = "Handykey Twiddler"; + input_dev->phys = twidjoy->phys; + input_dev->id.bustype = BUS_RS232; + input_dev->id.vendor = SERIO_TWIDJOY; + input_dev->id.product = 0x0001; + input_dev->id.version = 0x0100; + input_dev->dev.parent = &serio->dev; + + input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); + input_set_abs_params(input_dev, ABS_X, -50, 50, 4, 4); + input_set_abs_params(input_dev, ABS_Y, -50, 50, 4, 4); + + for (bp = twidjoy_buttons; bp->bitmask; bp++) + for (i = 0; i < bp->bitmask; i++) + set_bit(bp->buttons[i], input_dev->keybit); + + serio_set_drvdata(serio, twidjoy); + + err = serio_open(serio, drv); + if (err) + goto fail2; + + err = input_register_device(twidjoy->dev); + if (err) + goto fail3; + + return 0; + + fail3: serio_close(serio); + fail2: serio_set_drvdata(serio, NULL); + fail1: input_free_device(input_dev); + kfree(twidjoy); + return err; +} + +/* + * The serio driver structure. + */ + +static const struct serio_device_id twidjoy_serio_ids[] = { + { + .type = SERIO_RS232, + .proto = SERIO_TWIDJOY, + .id = SERIO_ANY, + .extra = SERIO_ANY, + }, + { 0 } +}; + +MODULE_DEVICE_TABLE(serio, twidjoy_serio_ids); + +static struct serio_driver twidjoy_drv = { + .driver = { + .name = "twidjoy", + }, + .description = DRIVER_DESC, + .id_table = twidjoy_serio_ids, + .interrupt = twidjoy_interrupt, + .connect = twidjoy_connect, + .disconnect = twidjoy_disconnect, +}; + +module_serio_driver(twidjoy_drv); |