From 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sun, 16 Aug 2026 15:32:33 +0200 Subject: kbuild: rust: keep Rust objects out of Clang LTO with inline helpers Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit `objtool` errors such as: vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a: can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd The reason is that in such builds, the Clang invocation that compiles the combined Rust plus helpers bitcode emits LLVM bitcode (again) -- the final code generation happens in the linker's LTO step, which the `-mllvm` trap options passed to Clang do not reach. This, in turn, means that unreachable traps are missing, and the impossible paths do not merely fallthrough to the next symbol, but past the end of their own section, since LTO builds place each function in its own section. Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always emits machine code directly, with the traps in place. Assisted-by: LLM Cc: Gary Guo Cc: Boqun Feng Cc: Alice Ryhl Cc: Matthew Maurer Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: stable@vger.kernel.org Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust") Acked-by: Gary Guo Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- drivers/input/touchscreen/elo.c | 406 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 406 insertions(+) create mode 100644 drivers/input/touchscreen/elo.c (limited to 'drivers/input/touchscreen/elo.c') diff --git a/drivers/input/touchscreen/elo.c b/drivers/input/touchscreen/elo.c new file mode 100644 index 000000000..6814d5789 --- /dev/null +++ b/drivers/input/touchscreen/elo.c @@ -0,0 +1,406 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Elo serial touchscreen driver + * + * Copyright (c) 2004 Vojtech Pavlik + */ + + +/* + * This driver can handle serial Elo touchscreens using either the Elo standard + * 'E271-2210' 10-byte protocol, Elo legacy 'E281A-4002' 6-byte protocol, Elo + * legacy 'E271-140' 4-byte protocol and Elo legacy 'E261-280' 3-byte protocol. + */ + +#include +#include +#include +#include +#include +#include +#include + +#define DRIVER_DESC "Elo serial touchscreen driver" + +MODULE_AUTHOR("Vojtech Pavlik "); +MODULE_DESCRIPTION(DRIVER_DESC); +MODULE_LICENSE("GPL"); + +/* + * Definitions & global arrays. + */ + +#define ELO_MAX_LENGTH 10 + +#define ELO10_PACKET_LEN 8 +#define ELO10_TOUCH 0x03 +#define ELO10_PRESSURE 0x80 + +#define ELO10_LEAD_BYTE 'U' + +#define ELO10_ID_CMD 'i' + +#define ELO10_TOUCH_PACKET 'T' +#define ELO10_ACK_PACKET 'A' +#define ELI10_ID_PACKET 'I' + +/* + * Per-touchscreen data. + */ + +struct elo { + struct input_dev *dev; + struct serio *serio; + struct mutex cmd_mutex; + struct completion cmd_done; + int id; + int idx; + unsigned char expected_packet; + unsigned char csum; + unsigned char data[ELO_MAX_LENGTH]; + unsigned char response[ELO10_PACKET_LEN]; + char phys[32]; +}; + +static void elo_process_data_10(struct elo *elo, unsigned char data) +{ + struct input_dev *dev = elo->dev; + + elo->data[elo->idx] = data; + + switch (elo->idx++) { + case 0: + elo->csum = 0xaa; + if (data != ELO10_LEAD_BYTE) { + dev_dbg(&elo->serio->dev, + "unsynchronized data: 0x%02x\n", data); + elo->idx = 0; + } + break; + + case 9: + elo->idx = 0; + if (data != elo->csum) { + dev_dbg(&elo->serio->dev, + "bad checksum: 0x%02x, expected 0x%02x\n", + data, elo->csum); + break; + } + if (elo->data[1] != elo->expected_packet) { + if (elo->data[1] != ELO10_TOUCH_PACKET) + dev_dbg(&elo->serio->dev, + "unexpected packet: 0x%02x\n", + elo->data[1]); + break; + } + if (likely(elo->data[1] == ELO10_TOUCH_PACKET)) { + input_report_abs(dev, ABS_X, (elo->data[4] << 8) | elo->data[3]); + input_report_abs(dev, ABS_Y, (elo->data[6] << 8) | elo->data[5]); + if (elo->data[2] & ELO10_PRESSURE) + input_report_abs(dev, ABS_PRESSURE, + (elo->data[8] << 8) | elo->data[7]); + input_report_key(dev, BTN_TOUCH, elo->data[2] & ELO10_TOUCH); + input_sync(dev); + } else if (elo->data[1] == ELO10_ACK_PACKET) { + if (elo->data[2] == '0') + elo->expected_packet = ELO10_TOUCH_PACKET; + complete(&elo->cmd_done); + } else { + memcpy(elo->response, &elo->data[1], ELO10_PACKET_LEN); + elo->expected_packet = ELO10_ACK_PACKET; + } + break; + } + elo->csum += data; +} + +static void elo_process_data_6(struct elo *elo, unsigned char data) +{ + struct input_dev *dev = elo->dev; + + elo->data[elo->idx] = data; + + switch (elo->idx++) { + + case 0: + if ((data & 0xc0) != 0xc0) + elo->idx = 0; + break; + + case 1: + if ((data & 0xc0) != 0x80) + elo->idx = 0; + break; + + case 2: + if ((data & 0xc0) != 0x40) + elo->idx = 0; + break; + + case 3: + if (data & 0xc0) { + elo->idx = 0; + break; + } + + input_report_abs(dev, ABS_X, ((elo->data[0] & 0x3f) << 6) | (elo->data[1] & 0x3f)); + input_report_abs(dev, ABS_Y, ((elo->data[2] & 0x3f) << 6) | (elo->data[3] & 0x3f)); + + if (elo->id == 2) { + input_report_key(dev, BTN_TOUCH, 1); + input_sync(dev); + elo->idx = 0; + } + + break; + + case 4: + if (data) { + input_sync(dev); + elo->idx = 0; + } + break; + + case 5: + if ((data & 0xf0) == 0) { + input_report_abs(dev, ABS_PRESSURE, elo->data[5]); + input_report_key(dev, BTN_TOUCH, !!elo->data[5]); + } + input_sync(dev); + elo->idx = 0; + break; + } +} + +static void elo_process_data_3(struct elo *elo, unsigned char data) +{ + struct input_dev *dev = elo->dev; + + elo->data[elo->idx] = data; + + switch (elo->idx++) { + + case 0: + if ((data & 0x7f) != 0x01) + elo->idx = 0; + break; + case 2: + input_report_key(dev, BTN_TOUCH, !(elo->data[1] & 0x80)); + input_report_abs(dev, ABS_X, elo->data[1]); + input_report_abs(dev, ABS_Y, elo->data[2]); + input_sync(dev); + elo->idx = 0; + break; + } +} + +static irqreturn_t elo_interrupt(struct serio *serio, + unsigned char data, unsigned int flags) +{ + struct elo *elo = serio_get_drvdata(serio); + + switch (elo->id) { + case 0: + elo_process_data_10(elo, data); + break; + + case 1: + case 2: + elo_process_data_6(elo, data); + break; + + case 3: + elo_process_data_3(elo, data); + break; + } + + return IRQ_HANDLED; +} + +static int elo_command_10(struct elo *elo, unsigned char *packet) +{ + int error; + int i; + unsigned char csum = 0xaa + ELO10_LEAD_BYTE; + + guard(mutex)(&elo->cmd_mutex); + + scoped_guard(serio_pause_rx, elo->serio) { + elo->expected_packet = toupper(packet[0]); + init_completion(&elo->cmd_done); + } + + error = serio_write(elo->serio, ELO10_LEAD_BYTE); + if (error) + return error; + + for (i = 0; i < ELO10_PACKET_LEN; i++) { + csum += packet[i]; + error = serio_write(elo->serio, packet[i]); + if (error) + return error; + } + + error = serio_write(elo->serio, csum); + if (error) + return error; + + wait_for_completion_timeout(&elo->cmd_done, HZ); + + if (elo->expected_packet != ELO10_TOUCH_PACKET) + return -EIO; + + /* We are back in reporting mode, the command was ACKed */ + memcpy(packet, elo->response, ELO10_PACKET_LEN); + return 0; +} + +static int elo_setup_10(struct elo *elo) +{ + static const char *elo_types[] = { "Accu", "Dura", "Intelli", "Carroll" }; + struct input_dev *dev = elo->dev; + unsigned char packet[ELO10_PACKET_LEN] = { ELO10_ID_CMD }; + + if (elo_command_10(elo, packet)) + return -1; + + dev->id.version = (packet[5] << 8) | packet[4]; + + input_set_abs_params(dev, ABS_X, 96, 4000, 0, 0); + input_set_abs_params(dev, ABS_Y, 96, 4000, 0, 0); + if (packet[3] & ELO10_PRESSURE) + input_set_abs_params(dev, ABS_PRESSURE, 0, 255, 0, 0); + + dev_info(&elo->serio->dev, + "%sTouch touchscreen, fw: %02x.%02x, features: 0x%02x, controller: 0x%02x\n", + elo_types[(packet[1] -'0') & 0x03], + packet[5], packet[4], packet[3], packet[7]); + + return 0; +} + +/* + * elo_disconnect() is the opposite of elo_connect() + */ + +static void elo_disconnect(struct serio *serio) +{ + struct elo *elo = serio_get_drvdata(serio); + + input_get_device(elo->dev); + input_unregister_device(elo->dev); + serio_close(serio); + serio_set_drvdata(serio, NULL); + input_put_device(elo->dev); + kfree(elo); +} + +/* + * elo_connect() is the routine that is called when someone adds a + * new serio device that supports Gunze protocol and registers it as + * an input device. + */ + +static int elo_connect(struct serio *serio, struct serio_driver *drv) +{ + struct elo *elo; + struct input_dev *input_dev; + int err; + + elo = kzalloc_obj(*elo); + input_dev = input_allocate_device(); + if (!elo || !input_dev) { + err = -ENOMEM; + goto fail1; + } + + elo->serio = serio; + elo->id = serio->id.id; + elo->dev = input_dev; + elo->expected_packet = ELO10_TOUCH_PACKET; + mutex_init(&elo->cmd_mutex); + init_completion(&elo->cmd_done); + scnprintf(elo->phys, sizeof(elo->phys), "%s/input0", serio->phys); + + input_dev->name = "Elo Serial TouchScreen"; + input_dev->phys = elo->phys; + input_dev->id.bustype = BUS_RS232; + input_dev->id.vendor = SERIO_ELO; + input_dev->id.product = elo->id; + 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); + + serio_set_drvdata(serio, elo); + err = serio_open(serio, drv); + if (err) + goto fail2; + + switch (elo->id) { + + case 0: /* 10-byte protocol */ + if (elo_setup_10(elo)) { + err = -EIO; + goto fail3; + } + + break; + + case 1: /* 6-byte protocol */ + input_set_abs_params(input_dev, ABS_PRESSURE, 0, 15, 0, 0); + fallthrough; + + case 2: /* 4-byte protocol */ + input_set_abs_params(input_dev, ABS_X, 96, 4000, 0, 0); + input_set_abs_params(input_dev, ABS_Y, 96, 4000, 0, 0); + break; + + case 3: /* 3-byte protocol */ + input_set_abs_params(input_dev, ABS_X, 0, 255, 0, 0); + input_set_abs_params(input_dev, ABS_Y, 0, 255, 0, 0); + break; + } + + err = input_register_device(elo->dev); + if (err) + goto fail3; + + return 0; + + fail3: serio_close(serio); + fail2: serio_set_drvdata(serio, NULL); + fail1: input_free_device(input_dev); + kfree(elo); + return err; +} + +/* + * The serio driver structure. + */ + +static const struct serio_device_id elo_serio_ids[] = { + { + .type = SERIO_RS232, + .proto = SERIO_ELO, + .id = SERIO_ANY, + .extra = SERIO_ANY, + }, + { 0 } +}; + +MODULE_DEVICE_TABLE(serio, elo_serio_ids); + +static struct serio_driver elo_drv = { + .driver = { + .name = "elo", + }, + .description = DRIVER_DESC, + .id_table = elo_serio_ids, + .interrupt = elo_interrupt, + .connect = elo_connect, + .disconnect = elo_disconnect, +}; + +module_serio_driver(elo_drv); -- cgit v1.3.1