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/keyboard/st-keyscan.c | 271 ++++++++++++++++++++++++++++++++++++ 1 file changed, 271 insertions(+) create mode 100644 drivers/input/keyboard/st-keyscan.c (limited to 'drivers/input/keyboard/st-keyscan.c') diff --git a/drivers/input/keyboard/st-keyscan.c b/drivers/input/keyboard/st-keyscan.c new file mode 100644 index 000000000..e53ef4c67 --- /dev/null +++ b/drivers/input/keyboard/st-keyscan.c @@ -0,0 +1,271 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * STMicroelectronics Key Scanning driver + * + * Copyright (c) 2014 STMicroelectonics Ltd. + * Author: Stuart Menefy + * + * Based on sh_keysc.c, copyright 2008 Magnus Damm + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#define ST_KEYSCAN_MAXKEYS 16 + +#define KEYSCAN_CONFIG_OFF 0x0 +#define KEYSCAN_CONFIG_ENABLE 0x1 +#define KEYSCAN_DEBOUNCE_TIME_OFF 0x4 +#define KEYSCAN_MATRIX_STATE_OFF 0x8 +#define KEYSCAN_MATRIX_DIM_OFF 0xc +#define KEYSCAN_MATRIX_DIM_X_SHIFT 0x0 +#define KEYSCAN_MATRIX_DIM_Y_SHIFT 0x2 + +struct st_keyscan { + void __iomem *base; + int irq; + struct clk *clk; + struct input_dev *input_dev; + unsigned long last_state; + unsigned int n_rows; + unsigned int n_cols; + unsigned int debounce_us; +}; + +static irqreturn_t keyscan_isr(int irq, void *dev_id) +{ + struct st_keyscan *keypad = dev_id; + unsigned short *keycode = keypad->input_dev->keycode; + unsigned long state, change; + int bit_nr; + + state = readl(keypad->base + KEYSCAN_MATRIX_STATE_OFF) & 0xffff; + change = keypad->last_state ^ state; + keypad->last_state = state; + + for_each_set_bit(bit_nr, &change, BITS_PER_LONG) + input_report_key(keypad->input_dev, + keycode[bit_nr], state & BIT(bit_nr)); + + input_sync(keypad->input_dev); + + return IRQ_HANDLED; +} + +static int keyscan_start(struct st_keyscan *keypad) +{ + int error; + + error = clk_enable(keypad->clk); + if (error) + return error; + + writel(keypad->debounce_us * (clk_get_rate(keypad->clk) / 1000000), + keypad->base + KEYSCAN_DEBOUNCE_TIME_OFF); + + writel(((keypad->n_cols - 1) << KEYSCAN_MATRIX_DIM_X_SHIFT) | + ((keypad->n_rows - 1) << KEYSCAN_MATRIX_DIM_Y_SHIFT), + keypad->base + KEYSCAN_MATRIX_DIM_OFF); + + writel(KEYSCAN_CONFIG_ENABLE, keypad->base + KEYSCAN_CONFIG_OFF); + + return 0; +} + +static void keyscan_stop(struct st_keyscan *keypad) +{ + writel(0, keypad->base + KEYSCAN_CONFIG_OFF); + + clk_disable(keypad->clk); +} + +static int keyscan_open(struct input_dev *dev) +{ + struct st_keyscan *keypad = input_get_drvdata(dev); + + return keyscan_start(keypad); +} + +static void keyscan_close(struct input_dev *dev) +{ + struct st_keyscan *keypad = input_get_drvdata(dev); + + keyscan_stop(keypad); +} + +static int keypad_matrix_key_parse_dt(struct st_keyscan *keypad_data) +{ + struct device *dev = keypad_data->input_dev->dev.parent; + struct device_node *np = dev->of_node; + int error; + + error = matrix_keypad_parse_properties(dev, &keypad_data->n_rows, + &keypad_data->n_cols); + if (error) { + dev_err(dev, "failed to parse keypad params\n"); + return error; + } + + of_property_read_u32(np, "st,debounce-us", &keypad_data->debounce_us); + + dev_dbg(dev, "n_rows=%d n_col=%d debounce=%d\n", + keypad_data->n_rows, keypad_data->n_cols, + keypad_data->debounce_us); + + return 0; +} + +static int keyscan_probe(struct platform_device *pdev) +{ + struct st_keyscan *keypad_data; + struct input_dev *input_dev; + int error; + + if (!pdev->dev.of_node) { + dev_err(&pdev->dev, "no DT data present\n"); + return -EINVAL; + } + + keypad_data = devm_kzalloc(&pdev->dev, sizeof(*keypad_data), + GFP_KERNEL); + if (!keypad_data) + return -ENOMEM; + + input_dev = devm_input_allocate_device(&pdev->dev); + if (!input_dev) { + dev_err(&pdev->dev, "failed to allocate the input device\n"); + return -ENOMEM; + } + + input_dev->name = pdev->name; + input_dev->phys = "keyscan-keys/input0"; + input_dev->dev.parent = &pdev->dev; + input_dev->open = keyscan_open; + input_dev->close = keyscan_close; + + input_dev->id.bustype = BUS_HOST; + + keypad_data->input_dev = input_dev; + + error = keypad_matrix_key_parse_dt(keypad_data); + if (error) + return error; + + error = matrix_keypad_build_keymap(NULL, NULL, + keypad_data->n_rows, + keypad_data->n_cols, + NULL, input_dev); + if (error) { + dev_err(&pdev->dev, "failed to build keymap\n"); + return error; + } + + input_set_drvdata(input_dev, keypad_data); + + keypad_data->base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL); + if (IS_ERR(keypad_data->base)) + return PTR_ERR(keypad_data->base); + + keypad_data->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(keypad_data->clk)) { + dev_err(&pdev->dev, "cannot get clock\n"); + return PTR_ERR(keypad_data->clk); + } + + error = clk_enable(keypad_data->clk); + if (error) { + dev_err(&pdev->dev, "failed to enable clock\n"); + return error; + } + + keyscan_stop(keypad_data); + + keypad_data->irq = platform_get_irq(pdev, 0); + if (keypad_data->irq < 0) + return -EINVAL; + + error = devm_request_irq(&pdev->dev, keypad_data->irq, keyscan_isr, 0, + pdev->name, keypad_data); + if (error) { + dev_err(&pdev->dev, "failed to request IRQ\n"); + return error; + } + + error = input_register_device(input_dev); + if (error) { + dev_err(&pdev->dev, "failed to register input device\n"); + return error; + } + + platform_set_drvdata(pdev, keypad_data); + + device_set_wakeup_capable(&pdev->dev, 1); + + return 0; +} + +static int keyscan_suspend(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct st_keyscan *keypad = platform_get_drvdata(pdev); + struct input_dev *input = keypad->input_dev; + + guard(mutex)(&input->mutex); + + if (device_may_wakeup(dev)) + enable_irq_wake(keypad->irq); + else if (input_device_enabled(input)) + keyscan_stop(keypad); + + return 0; +} + +static int keyscan_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct st_keyscan *keypad = platform_get_drvdata(pdev); + struct input_dev *input = keypad->input_dev; + int error; + + guard(mutex)(&input->mutex); + + if (device_may_wakeup(dev)) { + disable_irq_wake(keypad->irq); + } else if (input_device_enabled(input)) { + error = keyscan_start(keypad); + if (error) + return error; + } + + return 0; +} + +static DEFINE_SIMPLE_DEV_PM_OPS(keyscan_dev_pm_ops, + keyscan_suspend, keyscan_resume); + +static const struct of_device_id keyscan_of_match[] = { + { .compatible = "st,sti-keyscan" }, + { }, +}; +MODULE_DEVICE_TABLE(of, keyscan_of_match); + +static struct platform_driver keyscan_device_driver = { + .probe = keyscan_probe, + .driver = { + .name = "st-keyscan", + .pm = pm_sleep_ptr(&keyscan_dev_pm_ops), + .of_match_table = keyscan_of_match, + } +}; + +module_platform_driver(keyscan_device_driver); + +MODULE_AUTHOR("Stuart Menefy "); +MODULE_DESCRIPTION("STMicroelectronics keyscan device driver"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1