From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure --- drivers/rtc/rtc-cadence.c | 412 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 412 insertions(+) create mode 100644 drivers/rtc/rtc-cadence.c (limited to 'drivers/rtc/rtc-cadence.c') diff --git a/drivers/rtc/rtc-cadence.c b/drivers/rtc/rtc-cadence.c new file mode 100644 index 000000000..8634eea79 --- /dev/null +++ b/drivers/rtc/rtc-cadence.c @@ -0,0 +1,412 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Copyright 2019 Cadence + * + * Authors: + * Jan Kotas + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* Registers */ +#define CDNS_RTC_CTLR 0x00 +#define CDNS_RTC_HMR 0x04 +#define CDNS_RTC_TIMR 0x08 +#define CDNS_RTC_CALR 0x0C +#define CDNS_RTC_TIMAR 0x10 +#define CDNS_RTC_CALAR 0x14 +#define CDNS_RTC_AENR 0x18 +#define CDNS_RTC_EFLR 0x1C +#define CDNS_RTC_IENR 0x20 +#define CDNS_RTC_IDISR 0x24 +#define CDNS_RTC_IMSKR 0x28 +#define CDNS_RTC_STSR 0x2C +#define CDNS_RTC_KRTCR 0x30 + +/* Control */ +#define CDNS_RTC_CTLR_TIME BIT(0) +#define CDNS_RTC_CTLR_CAL BIT(1) +#define CDNS_RTC_CTLR_TIME_CAL (CDNS_RTC_CTLR_TIME | CDNS_RTC_CTLR_CAL) + +/* Status */ +#define CDNS_RTC_STSR_VT BIT(0) +#define CDNS_RTC_STSR_VC BIT(1) +#define CDNS_RTC_STSR_VTA BIT(2) +#define CDNS_RTC_STSR_VCA BIT(3) +#define CDNS_RTC_STSR_VT_VC (CDNS_RTC_STSR_VT | CDNS_RTC_STSR_VC) +#define CDNS_RTC_STSR_VTA_VCA (CDNS_RTC_STSR_VTA | CDNS_RTC_STSR_VCA) + +/* Keep RTC */ +#define CDNS_RTC_KRTCR_KRTC BIT(0) + +/* Alarm, Event, Interrupt */ +#define CDNS_RTC_AEI_HOS BIT(0) +#define CDNS_RTC_AEI_SEC BIT(1) +#define CDNS_RTC_AEI_MIN BIT(2) +#define CDNS_RTC_AEI_HOUR BIT(3) +#define CDNS_RTC_AEI_DATE BIT(4) +#define CDNS_RTC_AEI_MNTH BIT(5) +#define CDNS_RTC_AEI_ALRM BIT(6) + +/* Time */ +#define CDNS_RTC_TIME_H GENMASK(7, 0) +#define CDNS_RTC_TIME_S GENMASK(14, 8) +#define CDNS_RTC_TIME_M GENMASK(22, 16) +#define CDNS_RTC_TIME_HR GENMASK(29, 24) +#define CDNS_RTC_TIME_PM BIT(30) +#define CDNS_RTC_TIME_CH BIT(31) + +/* Calendar */ +#define CDNS_RTC_CAL_DAY GENMASK(2, 0) +#define CDNS_RTC_CAL_M GENMASK(7, 3) +#define CDNS_RTC_CAL_D GENMASK(13, 8) +#define CDNS_RTC_CAL_Y GENMASK(23, 16) +#define CDNS_RTC_CAL_C GENMASK(29, 24) +#define CDNS_RTC_CAL_CH BIT(31) + +#define CDNS_RTC_MAX_REGS_TRIES 3 + +struct cdns_rtc { + struct rtc_device *rtc_dev; + struct clk *pclk; + struct clk *ref_clk; + void __iomem *regs; + int irq; +}; + +static void cdns_rtc_set_enabled(struct cdns_rtc *crtc, bool enabled) +{ + u32 reg = enabled ? 0x0 : CDNS_RTC_CTLR_TIME_CAL; + + writel(reg, crtc->regs + CDNS_RTC_CTLR); +} + +static bool cdns_rtc_get_enabled(struct cdns_rtc *crtc) +{ + return !(readl(crtc->regs + CDNS_RTC_CTLR) & CDNS_RTC_CTLR_TIME_CAL); +} + +static irqreturn_t cdns_rtc_irq_handler(int irq, void *id) +{ + struct device *dev = id; + struct cdns_rtc *crtc = dev_get_drvdata(dev); + + /* Reading the register clears it */ + if (!(readl(crtc->regs + CDNS_RTC_EFLR) & CDNS_RTC_AEI_ALRM)) + return IRQ_NONE; + + rtc_update_irq(crtc->rtc_dev, 1, RTC_IRQF | RTC_AF); + return IRQ_HANDLED; +} + +static u32 cdns_rtc_time2reg(struct rtc_time *tm) +{ + return FIELD_PREP(CDNS_RTC_TIME_S, bin2bcd(tm->tm_sec)) + | FIELD_PREP(CDNS_RTC_TIME_M, bin2bcd(tm->tm_min)) + | FIELD_PREP(CDNS_RTC_TIME_HR, bin2bcd(tm->tm_hour)); +} + +static void cdns_rtc_reg2time(u32 reg, struct rtc_time *tm) +{ + tm->tm_sec = bcd2bin(FIELD_GET(CDNS_RTC_TIME_S, reg)); + tm->tm_min = bcd2bin(FIELD_GET(CDNS_RTC_TIME_M, reg)); + tm->tm_hour = bcd2bin(FIELD_GET(CDNS_RTC_TIME_HR, reg)); +} + +static int cdns_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct cdns_rtc *crtc = dev_get_drvdata(dev); + u32 reg; + + /* If the RTC is disabled, assume the values are invalid */ + if (!cdns_rtc_get_enabled(crtc)) + return -EINVAL; + + cdns_rtc_set_enabled(crtc, false); + + reg = readl(crtc->regs + CDNS_RTC_TIMR); + cdns_rtc_reg2time(reg, tm); + + reg = readl(crtc->regs + CDNS_RTC_CALR); + tm->tm_mday = bcd2bin(FIELD_GET(CDNS_RTC_CAL_D, reg)); + tm->tm_mon = bcd2bin(FIELD_GET(CDNS_RTC_CAL_M, reg)) - 1; + tm->tm_year = bcd2bin(FIELD_GET(CDNS_RTC_CAL_Y, reg)) + + bcd2bin(FIELD_GET(CDNS_RTC_CAL_C, reg)) * 100 - 1900; + tm->tm_wday = bcd2bin(FIELD_GET(CDNS_RTC_CAL_DAY, reg)) - 1; + + cdns_rtc_set_enabled(crtc, true); + return 0; +} + +static int cdns_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct cdns_rtc *crtc = dev_get_drvdata(dev); + u32 timr, calr, stsr; + int ret = -EIO; + int year = tm->tm_year + 1900; + int tries; + + cdns_rtc_set_enabled(crtc, false); + + timr = cdns_rtc_time2reg(tm); + + calr = FIELD_PREP(CDNS_RTC_CAL_D, bin2bcd(tm->tm_mday)) + | FIELD_PREP(CDNS_RTC_CAL_M, bin2bcd(tm->tm_mon + 1)) + | FIELD_PREP(CDNS_RTC_CAL_Y, bin2bcd(year % 100)) + | FIELD_PREP(CDNS_RTC_CAL_C, bin2bcd(year / 100)) + | FIELD_PREP(CDNS_RTC_CAL_DAY, tm->tm_wday + 1); + + /* Update registers, check valid flags */ + for (tries = 0; tries < CDNS_RTC_MAX_REGS_TRIES; tries++) { + writel(timr, crtc->regs + CDNS_RTC_TIMR); + writel(calr, crtc->regs + CDNS_RTC_CALR); + stsr = readl(crtc->regs + CDNS_RTC_STSR); + + if ((stsr & CDNS_RTC_STSR_VT_VC) == CDNS_RTC_STSR_VT_VC) { + ret = 0; + break; + } + } + + cdns_rtc_set_enabled(crtc, true); + return ret; +} + +static int cdns_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct cdns_rtc *crtc = dev_get_drvdata(dev); + + if (enabled) { + writel((CDNS_RTC_AEI_SEC | CDNS_RTC_AEI_MIN | CDNS_RTC_AEI_HOUR + | CDNS_RTC_AEI_DATE | CDNS_RTC_AEI_MNTH), + crtc->regs + CDNS_RTC_AENR); + writel(CDNS_RTC_AEI_ALRM, crtc->regs + CDNS_RTC_IENR); + } else { + writel(0, crtc->regs + CDNS_RTC_AENR); + writel(CDNS_RTC_AEI_ALRM, crtc->regs + CDNS_RTC_IDISR); + } + + return 0; +} + +static int cdns_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) +{ + struct cdns_rtc *crtc = dev_get_drvdata(dev); + u32 reg; + + reg = readl(crtc->regs + CDNS_RTC_TIMAR); + cdns_rtc_reg2time(reg, &alarm->time); + + reg = readl(crtc->regs + CDNS_RTC_CALAR); + alarm->time.tm_mday = bcd2bin(FIELD_GET(CDNS_RTC_CAL_D, reg)); + alarm->time.tm_mon = bcd2bin(FIELD_GET(CDNS_RTC_CAL_M, reg)) - 1; + + return 0; +} + +static int cdns_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) +{ + struct cdns_rtc *crtc = dev_get_drvdata(dev); + int ret = -EIO; + int tries; + u32 timar, calar, stsr; + + cdns_rtc_alarm_irq_enable(dev, 0); + + timar = cdns_rtc_time2reg(&alarm->time); + calar = FIELD_PREP(CDNS_RTC_CAL_D, bin2bcd(alarm->time.tm_mday)) + | FIELD_PREP(CDNS_RTC_CAL_M, bin2bcd(alarm->time.tm_mon + 1)); + + /* Update registers, check valid alarm flags */ + for (tries = 0; tries < CDNS_RTC_MAX_REGS_TRIES; tries++) { + writel(timar, crtc->regs + CDNS_RTC_TIMAR); + writel(calar, crtc->regs + CDNS_RTC_CALAR); + stsr = readl(crtc->regs + CDNS_RTC_STSR); + + if ((stsr & CDNS_RTC_STSR_VTA_VCA) == CDNS_RTC_STSR_VTA_VCA) { + ret = 0; + break; + } + } + + if (!ret) + cdns_rtc_alarm_irq_enable(dev, alarm->enabled); + return ret; +} + +static const struct rtc_class_ops cdns_rtc_ops = { + .read_time = cdns_rtc_read_time, + .set_time = cdns_rtc_set_time, + .read_alarm = cdns_rtc_read_alarm, + .set_alarm = cdns_rtc_set_alarm, + .alarm_irq_enable = cdns_rtc_alarm_irq_enable, +}; + +static int cdns_rtc_probe(struct platform_device *pdev) +{ + struct cdns_rtc *crtc; + int ret; + unsigned long ref_clk_freq; + + crtc = devm_kzalloc(&pdev->dev, sizeof(*crtc), GFP_KERNEL); + if (!crtc) + return -ENOMEM; + + crtc->regs = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(crtc->regs)) + return PTR_ERR(crtc->regs); + + crtc->irq = platform_get_irq(pdev, 0); + if (crtc->irq < 0) + return -EINVAL; + + crtc->pclk = devm_clk_get(&pdev->dev, "pclk"); + if (IS_ERR(crtc->pclk)) { + ret = PTR_ERR(crtc->pclk); + dev_err(&pdev->dev, + "Failed to retrieve the peripheral clock, %d\n", ret); + return ret; + } + + crtc->ref_clk = devm_clk_get(&pdev->dev, "ref_clk"); + if (IS_ERR(crtc->ref_clk)) { + ret = PTR_ERR(crtc->ref_clk); + dev_err(&pdev->dev, + "Failed to retrieve the reference clock, %d\n", ret); + return ret; + } + + crtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(crtc->rtc_dev)) + return PTR_ERR(crtc->rtc_dev); + + platform_set_drvdata(pdev, crtc); + + ret = clk_prepare_enable(crtc->pclk); + if (ret) { + dev_err(&pdev->dev, + "Failed to enable the peripheral clock, %d\n", ret); + return ret; + } + + ret = clk_prepare_enable(crtc->ref_clk); + if (ret) { + dev_err(&pdev->dev, + "Failed to enable the reference clock, %d\n", ret); + goto err_disable_pclk; + } + + ref_clk_freq = clk_get_rate(crtc->ref_clk); + if ((ref_clk_freq != 1) && (ref_clk_freq != 100)) { + dev_err(&pdev->dev, + "Invalid reference clock frequency %lu Hz.\n", + ref_clk_freq); + ret = -EINVAL; + goto err_disable_ref_clk; + } + + ret = devm_request_irq(&pdev->dev, crtc->irq, + cdns_rtc_irq_handler, 0, + dev_name(&pdev->dev), &pdev->dev); + if (ret) { + dev_err(&pdev->dev, + "Failed to request interrupt for the device, %d\n", + ret); + goto err_disable_ref_clk; + } + + /* The RTC supports 01.01.1900 - 31.12.2999 */ + crtc->rtc_dev->range_min = mktime64(1900, 1, 1, 0, 0, 0); + crtc->rtc_dev->range_max = mktime64(2999, 12, 31, 23, 59, 59); + + crtc->rtc_dev->ops = &cdns_rtc_ops; + device_init_wakeup(&pdev->dev, true); + + /* Always use 24-hour mode and keep the RTC values */ + writel(0, crtc->regs + CDNS_RTC_HMR); + writel(CDNS_RTC_KRTCR_KRTC, crtc->regs + CDNS_RTC_KRTCR); + + ret = devm_rtc_register_device(crtc->rtc_dev); + if (ret) + goto err_disable_wakeup; + + return 0; + +err_disable_wakeup: + device_init_wakeup(&pdev->dev, false); + +err_disable_ref_clk: + clk_disable_unprepare(crtc->ref_clk); + +err_disable_pclk: + clk_disable_unprepare(crtc->pclk); + + return ret; +} + +static void cdns_rtc_remove(struct platform_device *pdev) +{ + struct cdns_rtc *crtc = platform_get_drvdata(pdev); + + cdns_rtc_alarm_irq_enable(&pdev->dev, 0); + device_init_wakeup(&pdev->dev, false); + + clk_disable_unprepare(crtc->pclk); + clk_disable_unprepare(crtc->ref_clk); +} + +#ifdef CONFIG_PM_SLEEP +static int cdns_rtc_suspend(struct device *dev) +{ + struct cdns_rtc *crtc = dev_get_drvdata(dev); + + if (device_may_wakeup(dev)) + enable_irq_wake(crtc->irq); + + return 0; +} + +static int cdns_rtc_resume(struct device *dev) +{ + struct cdns_rtc *crtc = dev_get_drvdata(dev); + + if (device_may_wakeup(dev)) + disable_irq_wake(crtc->irq); + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(cdns_rtc_pm_ops, cdns_rtc_suspend, cdns_rtc_resume); + +static const struct of_device_id cdns_rtc_of_match[] = { + { .compatible = "cdns,rtc-r109v3" }, + { }, +}; +MODULE_DEVICE_TABLE(of, cdns_rtc_of_match); + +static struct platform_driver cdns_rtc_driver = { + .driver = { + .name = "cdns-rtc", + .of_match_table = cdns_rtc_of_match, + .pm = &cdns_rtc_pm_ops, + }, + .probe = cdns_rtc_probe, + .remove = cdns_rtc_remove, +}; +module_platform_driver(cdns_rtc_driver); + +MODULE_AUTHOR("Jan Kotas "); +MODULE_DESCRIPTION("Cadence RTC driver"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:cdns-rtc"); -- cgit v1.3.1