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/rtc/rtc-da9052.c | 333 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 333 insertions(+) create mode 100644 drivers/rtc/rtc-da9052.c (limited to 'drivers/rtc/rtc-da9052.c') diff --git a/drivers/rtc/rtc-da9052.c b/drivers/rtc/rtc-da9052.c new file mode 100644 index 000000000..9ca99bd35 --- /dev/null +++ b/drivers/rtc/rtc-da9052.c @@ -0,0 +1,333 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Real time clock driver for DA9052 + * + * Copyright(c) 2012 Dialog Semiconductor Ltd. + * + * Author: Dajun Dajun Chen + */ + +#include +#include +#include +#include +#include + +#include +#include + +#define rtc_err(rtc, fmt, ...) \ + dev_err(rtc->da9052->dev, "%s: " fmt, __func__, ##__VA_ARGS__) + +#define DA9052_GET_TIME_RETRIES 5 + +struct da9052_rtc { + struct rtc_device *rtc; + struct da9052 *da9052; +}; + +static int da9052_rtc_enable_alarm(struct da9052_rtc *rtc, bool enable) +{ + int ret; + if (enable) { + ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG, + DA9052_ALARM_Y_ALARM_ON|DA9052_ALARM_Y_TICK_ON, + DA9052_ALARM_Y_ALARM_ON); + if (ret != 0) + rtc_err(rtc, "Failed to enable ALM: %d\n", ret); + } else { + ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG, + DA9052_ALARM_Y_ALARM_ON|DA9052_ALARM_Y_TICK_ON, 0); + if (ret != 0) + rtc_err(rtc, "Write error: %d\n", ret); + } + return ret; +} + +static irqreturn_t da9052_rtc_irq(int irq, void *data) +{ + struct da9052_rtc *rtc = data; + + rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF); + + return IRQ_HANDLED; +} + +static int da9052_read_alarm(struct da9052_rtc *rtc, struct rtc_time *rtc_tm) +{ + int ret; + uint8_t v[2][5]; + int idx = 1; + int timeout = DA9052_GET_TIME_RETRIES; + + ret = da9052_group_read(rtc->da9052, DA9052_ALARM_MI_REG, 5, &v[0][0]); + if (ret) { + rtc_err(rtc, "Failed to group read ALM: %d\n", ret); + return ret; + } + + do { + ret = da9052_group_read(rtc->da9052, + DA9052_ALARM_MI_REG, 5, &v[idx][0]); + if (ret) { + rtc_err(rtc, "Failed to group read ALM: %d\n", ret); + return ret; + } + + if (memcmp(&v[0][0], &v[1][0], 5) == 0) { + rtc_tm->tm_year = (v[0][4] & DA9052_RTC_YEAR) + 100; + rtc_tm->tm_mon = (v[0][3] & DA9052_RTC_MONTH) - 1; + rtc_tm->tm_mday = v[0][2] & DA9052_RTC_DAY; + rtc_tm->tm_hour = v[0][1] & DA9052_RTC_HOUR; + rtc_tm->tm_min = v[0][0] & DA9052_RTC_MIN; + rtc_tm->tm_sec = 0; + + ret = rtc_valid_tm(rtc_tm); + return ret; + } + + idx = (1-idx); + msleep(20); + + } while (timeout--); + + rtc_err(rtc, "Timed out reading alarm time\n"); + + return -EIO; +} + +static int da9052_set_alarm(struct da9052_rtc *rtc, struct rtc_time *rtc_tm) +{ + struct da9052 *da9052 = rtc->da9052; + unsigned long alm_time; + int ret; + uint8_t v[3]; + + alm_time = rtc_tm_to_time64(rtc_tm); + + if (rtc_tm->tm_sec > 0) { + alm_time += 60 - rtc_tm->tm_sec; + rtc_time64_to_tm(alm_time, rtc_tm); + } + BUG_ON(rtc_tm->tm_sec); /* it will cause repeated irqs if not zero */ + + rtc_tm->tm_year -= 100; + rtc_tm->tm_mon += 1; + + ret = da9052_reg_update(da9052, DA9052_ALARM_MI_REG, + DA9052_RTC_MIN, rtc_tm->tm_min); + if (ret != 0) { + rtc_err(rtc, "Failed to write ALRM MIN: %d\n", ret); + return ret; + } + + v[0] = rtc_tm->tm_hour; + v[1] = rtc_tm->tm_mday; + v[2] = rtc_tm->tm_mon; + + ret = da9052_group_write(da9052, DA9052_ALARM_H_REG, 3, v); + if (ret < 0) + return ret; + + ret = da9052_reg_update(da9052, DA9052_ALARM_Y_REG, + DA9052_RTC_YEAR, rtc_tm->tm_year); + if (ret != 0) + rtc_err(rtc, "Failed to write ALRM YEAR: %d\n", ret); + + return ret; +} + +static int da9052_rtc_get_alarm_status(struct da9052_rtc *rtc) +{ + int ret; + + ret = da9052_reg_read(rtc->da9052, DA9052_ALARM_Y_REG); + if (ret < 0) { + rtc_err(rtc, "Failed to read ALM: %d\n", ret); + return ret; + } + + return !!(ret&DA9052_ALARM_Y_ALARM_ON); +} + +static int da9052_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm) +{ + struct da9052_rtc *rtc = dev_get_drvdata(dev); + int ret; + uint8_t v[2][6]; + int idx = 1; + int timeout = DA9052_GET_TIME_RETRIES; + + ret = da9052_group_read(rtc->da9052, DA9052_COUNT_S_REG, 6, &v[0][0]); + if (ret) { + rtc_err(rtc, "Failed to read RTC time : %d\n", ret); + return ret; + } + + do { + ret = da9052_group_read(rtc->da9052, + DA9052_COUNT_S_REG, 6, &v[idx][0]); + if (ret) { + rtc_err(rtc, "Failed to read RTC time : %d\n", ret); + return ret; + } + + if (memcmp(&v[0][0], &v[1][0], 6) == 0) { + rtc_tm->tm_year = (v[0][5] & DA9052_RTC_YEAR) + 100; + rtc_tm->tm_mon = (v[0][4] & DA9052_RTC_MONTH) - 1; + rtc_tm->tm_mday = v[0][3] & DA9052_RTC_DAY; + rtc_tm->tm_hour = v[0][2] & DA9052_RTC_HOUR; + rtc_tm->tm_min = v[0][1] & DA9052_RTC_MIN; + rtc_tm->tm_sec = v[0][0] & DA9052_RTC_SEC; + + return 0; + } + + idx = (1-idx); + msleep(20); + + } while (timeout--); + + rtc_err(rtc, "Timed out reading time\n"); + + return -EIO; +} + +static int da9052_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct da9052_rtc *rtc; + uint8_t v[6]; + int ret; + + /* DA9052 only has 6 bits for year - to represent 2000-2063 */ + if ((tm->tm_year < 100) || (tm->tm_year > 163)) + return -EINVAL; + + rtc = dev_get_drvdata(dev); + + v[0] = tm->tm_sec; + v[1] = tm->tm_min; + v[2] = tm->tm_hour; + v[3] = tm->tm_mday; + v[4] = tm->tm_mon + 1; + v[5] = tm->tm_year - 100; + + ret = da9052_group_write(rtc->da9052, DA9052_COUNT_S_REG, 6, v); + if (ret < 0) + rtc_err(rtc, "failed to set RTC time: %d\n", ret); + return ret; +} + +static int da9052_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + int ret; + struct rtc_time *tm = &alrm->time; + struct da9052_rtc *rtc = dev_get_drvdata(dev); + + ret = da9052_read_alarm(rtc, tm); + if (ret < 0) { + rtc_err(rtc, "failed to read RTC alarm: %d\n", ret); + return ret; + } + + alrm->enabled = da9052_rtc_get_alarm_status(rtc); + return 0; +} + +static int da9052_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + int ret; + struct rtc_time *tm = &alrm->time; + struct da9052_rtc *rtc = dev_get_drvdata(dev); + + /* DA9052 only has 6 bits for year - to represent 2000-2063 */ + if ((tm->tm_year < 100) || (tm->tm_year > 163)) + return -EINVAL; + + ret = da9052_rtc_enable_alarm(rtc, 0); + if (ret < 0) + return ret; + + ret = da9052_set_alarm(rtc, tm); + if (ret < 0) + return ret; + + ret = da9052_rtc_enable_alarm(rtc, 1); + return ret; +} + +static int da9052_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct da9052_rtc *rtc = dev_get_drvdata(dev); + + return da9052_rtc_enable_alarm(rtc, enabled); +} + +static const struct rtc_class_ops da9052_rtc_ops = { + .read_time = da9052_rtc_read_time, + .set_time = da9052_rtc_set_time, + .read_alarm = da9052_rtc_read_alarm, + .set_alarm = da9052_rtc_set_alarm, + .alarm_irq_enable = da9052_rtc_alarm_irq_enable, +}; + +static int da9052_rtc_probe(struct platform_device *pdev) +{ + struct da9052_rtc *rtc; + int ret; + + rtc = devm_kzalloc(&pdev->dev, sizeof(struct da9052_rtc), GFP_KERNEL); + if (!rtc) + return -ENOMEM; + + rtc->da9052 = dev_get_drvdata(pdev->dev.parent); + platform_set_drvdata(pdev, rtc); + + ret = da9052_reg_write(rtc->da9052, DA9052_BBAT_CONT_REG, 0xFE); + if (ret < 0) { + rtc_err(rtc, + "Failed to setup RTC battery charging: %d\n", ret); + return ret; + } + + ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG, + DA9052_ALARM_Y_TICK_ON, 0); + if (ret != 0) + rtc_err(rtc, "Failed to disable TICKS: %d\n", ret); + + device_init_wakeup(&pdev->dev, true); + rtc->rtc = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(rtc->rtc)) + return PTR_ERR(rtc->rtc); + + rtc->rtc->ops = &da9052_rtc_ops; + rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; + rtc->rtc->range_max = RTC_TIMESTAMP_END_2063; + + ret = devm_rtc_register_device(rtc->rtc); + if (ret) + return ret; + + ret = da9052_request_irq(rtc->da9052, DA9052_IRQ_ALARM, "ALM", + da9052_rtc_irq, rtc); + if (ret != 0) { + rtc_err(rtc, "irq registration failed: %d\n", ret); + return ret; + } + + return 0; +} + +static struct platform_driver da9052_rtc_driver = { + .probe = da9052_rtc_probe, + .driver = { + .name = "da9052-rtc", + }, +}; + +module_platform_driver(da9052_rtc_driver); + +MODULE_AUTHOR("Anthony Olech "); +MODULE_DESCRIPTION("RTC driver for Dialog DA9052 PMIC"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:da9052-rtc"); -- cgit v1.3.1