From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001 From: Zeng Chi Date: Mon, 21 Sep 2026 18:24:42 +0800 Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson Cc: David Ballesteros Signed-off-by: Zeng Chi Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson --- drivers/input/touchscreen/mtouch.c | 200 +++++++++++++++++++++++++++++++++++++ 1 file changed, 200 insertions(+) create mode 100644 drivers/input/touchscreen/mtouch.c (limited to 'drivers/input/touchscreen/mtouch.c') diff --git a/drivers/input/touchscreen/mtouch.c b/drivers/input/touchscreen/mtouch.c new file mode 100644 index 000000000..cc2d206d2 --- /dev/null +++ b/drivers/input/touchscreen/mtouch.c @@ -0,0 +1,200 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * MicroTouch (3M) serial touchscreen driver + * + * Copyright (c) 2004 Vojtech Pavlik + */ + + +/* + * 2005/02/19 Dan Streetman + * Copied elo.c and edited for MicroTouch protocol + */ + +#include +#include +#include +#include +#include +#include + +#define DRIVER_DESC "MicroTouch serial touchscreen driver" + +MODULE_AUTHOR("Vojtech Pavlik "); +MODULE_DESCRIPTION(DRIVER_DESC); +MODULE_LICENSE("GPL"); + +/* + * Definitions & global arrays. + */ + +#define MTOUCH_FORMAT_TABLET_STATUS_BIT 0x80 +#define MTOUCH_FORMAT_TABLET_TOUCH_BIT 0x40 +#define MTOUCH_FORMAT_TABLET_LENGTH 5 +#define MTOUCH_RESPONSE_BEGIN_BYTE 0x01 +#define MTOUCH_RESPONSE_END_BYTE 0x0d + +/* todo: check specs for max length of all responses */ +#define MTOUCH_MAX_LENGTH 16 + +#define MTOUCH_MIN_XC 0 +#define MTOUCH_MAX_XC 0x3fff +#define MTOUCH_MIN_YC 0 +#define MTOUCH_MAX_YC 0x3fff + +#define MTOUCH_GET_XC(data) (((data[2])<<7) | data[1]) +#define MTOUCH_GET_YC(data) (((data[4])<<7) | data[3]) +#define MTOUCH_GET_TOUCHED(data) (MTOUCH_FORMAT_TABLET_TOUCH_BIT & data[0]) + +/* + * Per-touchscreen data. + */ + +struct mtouch { + struct input_dev *dev; + struct serio *serio; + int idx; + unsigned char data[MTOUCH_MAX_LENGTH]; + char phys[32]; +}; + +static void mtouch_process_format_tablet(struct mtouch *mtouch) +{ + struct input_dev *dev = mtouch->dev; + + if (MTOUCH_FORMAT_TABLET_LENGTH == ++mtouch->idx) { + input_report_abs(dev, ABS_X, MTOUCH_GET_XC(mtouch->data)); + input_report_abs(dev, ABS_Y, MTOUCH_MAX_YC - MTOUCH_GET_YC(mtouch->data)); + input_report_key(dev, BTN_TOUCH, MTOUCH_GET_TOUCHED(mtouch->data)); + input_sync(dev); + + mtouch->idx = 0; + } +} + +static void mtouch_process_response(struct mtouch *mtouch) +{ + if (MTOUCH_RESPONSE_END_BYTE == mtouch->data[mtouch->idx++]) { + /* FIXME - process response */ + mtouch->idx = 0; + } else if (MTOUCH_MAX_LENGTH == mtouch->idx) { + printk(KERN_ERR "mtouch.c: too many response bytes\n"); + mtouch->idx = 0; + } +} + +static irqreturn_t mtouch_interrupt(struct serio *serio, + unsigned char data, unsigned int flags) +{ + struct mtouch *mtouch = serio_get_drvdata(serio); + + mtouch->data[mtouch->idx] = data; + + if (MTOUCH_FORMAT_TABLET_STATUS_BIT & mtouch->data[0]) + mtouch_process_format_tablet(mtouch); + else if (MTOUCH_RESPONSE_BEGIN_BYTE == mtouch->data[0]) + mtouch_process_response(mtouch); + else + printk(KERN_DEBUG "mtouch.c: unknown/unsynchronized data from device, byte %x\n",mtouch->data[0]); + + return IRQ_HANDLED; +} + +/* + * mtouch_disconnect() is the opposite of mtouch_connect() + */ + +static void mtouch_disconnect(struct serio *serio) +{ + struct mtouch *mtouch = serio_get_drvdata(serio); + + input_get_device(mtouch->dev); + input_unregister_device(mtouch->dev); + serio_close(serio); + serio_set_drvdata(serio, NULL); + input_put_device(mtouch->dev); + kfree(mtouch); +} + +/* + * mtouch_connect() is the routine that is called when someone adds a + * new serio device that supports MicroTouch (Format Tablet) protocol and registers it as + * an input device. + */ + +static int mtouch_connect(struct serio *serio, struct serio_driver *drv) +{ + struct mtouch *mtouch; + struct input_dev *input_dev; + int err; + + mtouch = kzalloc_obj(*mtouch); + input_dev = input_allocate_device(); + if (!mtouch || !input_dev) { + err = -ENOMEM; + goto fail1; + } + + mtouch->serio = serio; + mtouch->dev = input_dev; + scnprintf(mtouch->phys, sizeof(mtouch->phys), "%s/input0", serio->phys); + + input_dev->name = "MicroTouch Serial TouchScreen"; + input_dev->phys = mtouch->phys; + input_dev->id.bustype = BUS_RS232; + input_dev->id.vendor = SERIO_MICROTOUCH; + input_dev->id.product = 0; + input_dev->id.version = 0x0100; + input_dev->dev.parent = &serio->dev; + input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); + input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); + input_set_abs_params(mtouch->dev, ABS_X, MTOUCH_MIN_XC, MTOUCH_MAX_XC, 0, 0); + input_set_abs_params(mtouch->dev, ABS_Y, MTOUCH_MIN_YC, MTOUCH_MAX_YC, 0, 0); + + serio_set_drvdata(serio, mtouch); + + err = serio_open(serio, drv); + if (err) + goto fail2; + + err = input_register_device(mtouch->dev); + if (err) + goto fail3; + + return 0; + + fail3: serio_close(serio); + fail2: serio_set_drvdata(serio, NULL); + fail1: input_free_device(input_dev); + kfree(mtouch); + return err; +} + +/* + * The serio driver structure. + */ + +static const struct serio_device_id mtouch_serio_ids[] = { + { + .type = SERIO_RS232, + .proto = SERIO_MICROTOUCH, + .id = SERIO_ANY, + .extra = SERIO_ANY, + }, + { 0 } +}; + +MODULE_DEVICE_TABLE(serio, mtouch_serio_ids); + +static struct serio_driver mtouch_drv = { + .driver = { + .name = "mtouch", + }, + .description = DRIVER_DESC, + .id_table = mtouch_serio_ids, + .interrupt = mtouch_interrupt, + .connect = mtouch_connect, + .disconnect = mtouch_disconnect, +}; + +module_serio_driver(mtouch_drv); -- cgit v1.3.1