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-rw-r--r--drivers/input/joystick/twidjoy.c244
1 files changed, 244 insertions, 0 deletions
diff --git a/drivers/input/joystick/twidjoy.c b/drivers/input/joystick/twidjoy.c
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+++ b/drivers/input/joystick/twidjoy.c
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+// 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);