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/mouse/focaltech.c | 455 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 455 insertions(+) create mode 100644 drivers/input/mouse/focaltech.c (limited to 'drivers/input/mouse/focaltech.c') diff --git a/drivers/input/mouse/focaltech.c b/drivers/input/mouse/focaltech.c new file mode 100644 index 000000000..d3ad4af5a --- /dev/null +++ b/drivers/input/mouse/focaltech.c @@ -0,0 +1,455 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Focaltech TouchPad PS/2 mouse driver + * + * Copyright (c) 2014 Red Hat Inc. + * Copyright (c) 2014 Mathias Gottschlag + * + * Red Hat authors: + * + * Hans de Goede + */ + + +#include +#include +#include +#include +#include +#include "psmouse.h" +#include "focaltech.h" + +static const char * const focaltech_pnp_ids[] = { + "FLT0101", + "FLT0102", + "FLT0103", + NULL +}; + +/* + * Even if the kernel is built without support for Focaltech PS/2 touchpads (or + * when the real driver fails to recognize the device), we still have to detect + * them in order to avoid further detection attempts confusing the touchpad. + * This way it at least works in PS/2 mouse compatibility mode. + */ +int focaltech_detect(struct psmouse *psmouse, bool set_properties) +{ + if (!psmouse_matches_pnp_id(psmouse, focaltech_pnp_ids)) + return -ENODEV; + + if (set_properties) { + psmouse->vendor = "FocalTech"; + psmouse->name = "Touchpad"; + } + + return 0; +} + +#ifdef CONFIG_MOUSE_PS2_FOCALTECH + +/* + * Packet types - the numbers are not consecutive, so we might be missing + * something here. + */ +#define FOC_TOUCH 0x3 /* bitmap of active fingers */ +#define FOC_ABS 0x6 /* absolute position of one finger */ +#define FOC_REL 0x9 /* relative position of 1-2 fingers */ + +#define FOC_MAX_FINGERS 5 + +/* + * Current state of a single finger on the touchpad. + */ +struct focaltech_finger_state { + /* The touchpad has generated a touch event for the finger */ + bool active; + + /* + * The touchpad has sent position data for the finger. The + * flag is 0 when the finger is not active, and there is a + * time between the first touch event for the finger and the + * following absolute position packet for the finger where the + * touchpad has declared the finger to be valid, but we do not + * have any valid position yet. + */ + bool valid; + + /* + * Absolute position (from the bottom left corner) of the + * finger. + */ + unsigned int x; + unsigned int y; +}; + +/* + * Description of the current state of the touchpad hardware. + */ +struct focaltech_hw_state { + /* + * The touchpad tracks the positions of the fingers for us, + * the array indices correspond to the finger indices returned + * in the report packages. + */ + struct focaltech_finger_state fingers[FOC_MAX_FINGERS]; + + /* + * Finger width 0-7 and 15 for a very big contact area. + * 15 value stays until the finger is released. + * Width is reported only in absolute packets. + * Since hardware reports width only for last touching finger, + * there is no need to store width for every specific finger, + * so we keep only last value reported. + */ + unsigned int width; + + /* True if the clickpad has been pressed. */ + bool pressed; +}; + +struct focaltech_data { + unsigned int x_max, y_max; + struct focaltech_hw_state state; +}; + +static void focaltech_report_state(struct psmouse *psmouse) +{ + struct focaltech_data *priv = psmouse->private; + struct focaltech_hw_state *state = &priv->state; + struct input_dev *dev = psmouse->dev; + int i; + + for (i = 0; i < FOC_MAX_FINGERS; i++) { + struct focaltech_finger_state *finger = &state->fingers[i]; + bool active = finger->active && finger->valid; + + input_mt_slot(dev, i); + input_mt_report_slot_state(dev, MT_TOOL_FINGER, active); + if (active) { + unsigned int clamped_x, clamped_y; + /* + * The touchpad might report invalid data, so we clamp + * the resulting values so that we do not confuse + * userspace. + */ + clamped_x = clamp(finger->x, 0U, priv->x_max); + clamped_y = clamp(finger->y, 0U, priv->y_max); + input_report_abs(dev, ABS_MT_POSITION_X, clamped_x); + input_report_abs(dev, ABS_MT_POSITION_Y, + priv->y_max - clamped_y); + input_report_abs(dev, ABS_TOOL_WIDTH, state->width); + } + } + input_mt_report_pointer_emulation(dev, true); + + input_report_key(dev, BTN_LEFT, state->pressed); + input_sync(dev); +} + +static void focaltech_process_touch_packet(struct psmouse *psmouse, + unsigned char *packet) +{ + struct focaltech_data *priv = psmouse->private; + struct focaltech_hw_state *state = &priv->state; + unsigned char fingers = packet[1]; + int i; + + state->pressed = (packet[0] >> 4) & 1; + + /* the second byte contains a bitmap of all fingers touching the pad */ + for (i = 0; i < FOC_MAX_FINGERS; i++) { + state->fingers[i].active = fingers & 0x1; + if (!state->fingers[i].active) { + /* + * Even when the finger becomes active again, we still + * will have to wait for the first valid position. + */ + state->fingers[i].valid = false; + } + fingers >>= 1; + } +} + +static void focaltech_process_abs_packet(struct psmouse *psmouse, + unsigned char *packet) +{ + struct focaltech_data *priv = psmouse->private; + struct focaltech_hw_state *state = &priv->state; + unsigned int finger; + + finger = (packet[1] >> 4) - 1; + if (finger >= FOC_MAX_FINGERS) { + psmouse_err(psmouse, "Invalid finger in abs packet: %d\n", + finger); + return; + } + + state->pressed = (packet[0] >> 4) & 1; + + state->fingers[finger].x = ((packet[1] & 0xf) << 8) | packet[2]; + state->fingers[finger].y = (packet[3] << 8) | packet[4]; + state->width = packet[5] >> 4; + state->fingers[finger].valid = true; +} + +static void focaltech_process_rel_packet(struct psmouse *psmouse, + unsigned char *packet) +{ + struct focaltech_data *priv = psmouse->private; + struct focaltech_hw_state *state = &priv->state; + unsigned int finger1, finger2; + + state->pressed = packet[0] >> 7; + finger1 = ((packet[0] >> 4) & 0x7) - 1; + if (finger1 < FOC_MAX_FINGERS) { + state->fingers[finger1].x += (s8)packet[1]; + state->fingers[finger1].y += (s8)packet[2]; + } else { + psmouse_err(psmouse, "First finger in rel packet invalid: %d\n", + finger1); + } + + /* + * If there is an odd number of fingers, the last relative + * packet only contains one finger. In this case, the second + * finger index in the packet is 0 (we subtract 1 in the lines + * above to create array indices, so the finger will overflow + * and be above FOC_MAX_FINGERS). + */ + finger2 = ((packet[3] >> 4) & 0x7) - 1; + if (finger2 < FOC_MAX_FINGERS) { + state->fingers[finger2].x += (s8)packet[4]; + state->fingers[finger2].y += (s8)packet[5]; + } +} + +static void focaltech_process_packet(struct psmouse *psmouse) +{ + unsigned char *packet = psmouse->packet; + + switch (packet[0] & 0xf) { + case FOC_TOUCH: + focaltech_process_touch_packet(psmouse, packet); + break; + + case FOC_ABS: + focaltech_process_abs_packet(psmouse, packet); + break; + + case FOC_REL: + focaltech_process_rel_packet(psmouse, packet); + break; + + default: + psmouse_err(psmouse, "Unknown packet type: %02x\n", packet[0]); + break; + } + + focaltech_report_state(psmouse); +} + +static psmouse_ret_t focaltech_process_byte(struct psmouse *psmouse) +{ + if (psmouse->pktcnt >= 6) { /* Full packet received */ + focaltech_process_packet(psmouse); + return PSMOUSE_FULL_PACKET; + } + + /* + * We might want to do some validation of the data here, but + * we do not know the protocol well enough + */ + return PSMOUSE_GOOD_DATA; +} + +static int focaltech_switch_protocol(struct psmouse *psmouse) +{ + struct ps2dev *ps2dev = &psmouse->ps2dev; + unsigned char param[3]; + + param[0] = 0; + if (ps2_command(ps2dev, param, 0x10f8)) + return -EIO; + + if (ps2_command(ps2dev, param, 0x10f8)) + return -EIO; + + if (ps2_command(ps2dev, param, 0x10f8)) + return -EIO; + + param[0] = 1; + if (ps2_command(ps2dev, param, 0x10f8)) + return -EIO; + + if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETSCALE11)) + return -EIO; + + if (ps2_command(ps2dev, param, PSMOUSE_CMD_ENABLE)) + return -EIO; + + return 0; +} + +static void focaltech_reset(struct psmouse *psmouse) +{ + ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS); + psmouse_reset(psmouse); +} + +static void focaltech_disconnect(struct psmouse *psmouse) +{ + focaltech_reset(psmouse); + kfree(psmouse->private); + psmouse->private = NULL; +} + +static int focaltech_reconnect(struct psmouse *psmouse) +{ + int error; + + focaltech_reset(psmouse); + + error = focaltech_switch_protocol(psmouse); + if (error) { + psmouse_err(psmouse, "Unable to initialize the device\n"); + return error; + } + + return 0; +} + +static void focaltech_set_input_params(struct psmouse *psmouse) +{ + struct input_dev *dev = psmouse->dev; + struct focaltech_data *priv = psmouse->private; + + /* + * Undo part of setup done for us by psmouse core since touchpad + * is not a relative device. + */ + __clear_bit(EV_REL, dev->evbit); + __clear_bit(REL_X, dev->relbit); + __clear_bit(REL_Y, dev->relbit); + __clear_bit(BTN_RIGHT, dev->keybit); + __clear_bit(BTN_MIDDLE, dev->keybit); + + /* + * Now set up our capabilities. + */ + __set_bit(EV_ABS, dev->evbit); + input_set_abs_params(dev, ABS_MT_POSITION_X, 0, priv->x_max, 0, 0); + input_set_abs_params(dev, ABS_MT_POSITION_Y, 0, priv->y_max, 0, 0); + input_set_abs_params(dev, ABS_TOOL_WIDTH, 0, 15, 0, 0); + input_mt_init_slots(dev, 5, INPUT_MT_POINTER); + __set_bit(INPUT_PROP_BUTTONPAD, dev->propbit); +} + +static int focaltech_read_register(struct ps2dev *ps2dev, int reg, + unsigned char *param) +{ + if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETSCALE11)) + return -EIO; + + param[0] = 0; + if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES)) + return -EIO; + + if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES)) + return -EIO; + + if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES)) + return -EIO; + + param[0] = reg; + if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES)) + return -EIO; + + if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) + return -EIO; + + return 0; +} + +static int focaltech_read_size(struct psmouse *psmouse) +{ + struct ps2dev *ps2dev = &psmouse->ps2dev; + struct focaltech_data *priv = psmouse->private; + char param[3]; + + if (focaltech_read_register(ps2dev, 2, param)) + return -EIO; + + /* not sure whether this is 100% correct */ + priv->x_max = (unsigned char)param[1] * 128; + priv->y_max = (unsigned char)param[2] * 128; + + return 0; +} + +static void focaltech_set_resolution(struct psmouse *psmouse, + unsigned int resolution) +{ + /* not supported yet */ +} + +static void focaltech_set_rate(struct psmouse *psmouse, unsigned int rate) +{ + /* not supported yet */ +} + +static void focaltech_set_scale(struct psmouse *psmouse, + enum psmouse_scale scale) +{ + /* not supported yet */ +} + +int focaltech_init(struct psmouse *psmouse) +{ + struct focaltech_data *priv; + int error; + + psmouse->private = priv = kzalloc_obj(*priv); + if (!priv) + return -ENOMEM; + + focaltech_reset(psmouse); + + error = focaltech_read_size(psmouse); + if (error) { + psmouse_err(psmouse, + "Unable to read the size of the touchpad\n"); + goto fail; + } + + error = focaltech_switch_protocol(psmouse); + if (error) { + psmouse_err(psmouse, "Unable to initialize the device\n"); + goto fail; + } + + focaltech_set_input_params(psmouse); + + psmouse->protocol_handler = focaltech_process_byte; + psmouse->pktsize = 6; + psmouse->disconnect = focaltech_disconnect; + psmouse->reconnect = focaltech_reconnect; + psmouse->cleanup = focaltech_reset; + /* resync is not supported yet */ + psmouse->resync_time = 0; + /* + * rate/resolution/scale changes are not supported yet, and + * the generic implementations of these functions seem to + * confuse some touchpads + */ + psmouse->set_resolution = focaltech_set_resolution; + psmouse->set_rate = focaltech_set_rate; + psmouse->set_scale = focaltech_set_scale; + + return 0; + +fail: + focaltech_reset(psmouse); + kfree(priv); + return error; +} +#endif /* CONFIG_MOUSE_PS2_FOCALTECH */ -- cgit v1.3.1