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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /drivers/input/joystick/twidjoy.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'drivers/input/joystick/twidjoy.c')
-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
new file mode 100644
index 000000000..fb452552c
--- /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_obj(*twidjoy);
+ 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);