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-spear.c | 492 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 492 insertions(+) create mode 100644 drivers/rtc/rtc-spear.c (limited to 'drivers/rtc/rtc-spear.c') diff --git a/drivers/rtc/rtc-spear.c b/drivers/rtc/rtc-spear.c new file mode 100644 index 000000000..959acff8f --- /dev/null +++ b/drivers/rtc/rtc-spear.c @@ -0,0 +1,492 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * drivers/rtc/rtc-spear.c + * + * Copyright (C) 2010 ST Microelectronics + * Rajeev Kumar + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* RTC registers */ +#define TIME_REG 0x00 +#define DATE_REG 0x04 +#define ALARM_TIME_REG 0x08 +#define ALARM_DATE_REG 0x0C +#define CTRL_REG 0x10 +#define STATUS_REG 0x14 + +/* TIME_REG & ALARM_TIME_REG */ +#define SECONDS_UNITS (0xf<<0) /* seconds units position */ +#define SECONDS_TENS (0x7<<4) /* seconds tens position */ +#define MINUTES_UNITS (0xf<<8) /* minutes units position */ +#define MINUTES_TENS (0x7<<12) /* minutes tens position */ +#define HOURS_UNITS (0xf<<16) /* hours units position */ +#define HOURS_TENS (0x3<<20) /* hours tens position */ + +/* DATE_REG & ALARM_DATE_REG */ +#define DAYS_UNITS (0xf<<0) /* days units position */ +#define DAYS_TENS (0x3<<4) /* days tens position */ +#define MONTHS_UNITS (0xf<<8) /* months units position */ +#define MONTHS_TENS (0x1<<12) /* months tens position */ +#define YEARS_UNITS (0xf<<16) /* years units position */ +#define YEARS_TENS (0xf<<20) /* years tens position */ +#define YEARS_HUNDREDS (0xf<<24) /* years hundereds position */ +#define YEARS_MILLENIUMS (0xf<<28) /* years millenium position */ + +/* MASK SHIFT TIME_REG & ALARM_TIME_REG*/ +#define SECOND_SHIFT 0x00 /* seconds units */ +#define MINUTE_SHIFT 0x08 /* minutes units position */ +#define HOUR_SHIFT 0x10 /* hours units position */ +#define MDAY_SHIFT 0x00 /* Month day shift */ +#define MONTH_SHIFT 0x08 /* Month shift */ +#define YEAR_SHIFT 0x10 /* Year shift */ + +#define SECOND_MASK 0x7F +#define MIN_MASK 0x7F +#define HOUR_MASK 0x3F +#define DAY_MASK 0x3F +#define MONTH_MASK 0x7F +#define YEAR_MASK 0xFFFF + +/* date reg equal to time reg, for debug only */ +#define TIME_BYP (1<<9) +#define INT_ENABLE (1<<31) /* interrupt enable */ + +/* STATUS_REG */ +#define CLK_UNCONNECTED (1<<0) +#define PEND_WR_TIME (1<<2) +#define PEND_WR_DATE (1<<3) +#define LOST_WR_TIME (1<<4) +#define LOST_WR_DATE (1<<5) +#define RTC_INT_MASK (1<<31) +#define STATUS_BUSY (PEND_WR_TIME | PEND_WR_DATE) +#define STATUS_FAIL (LOST_WR_TIME | LOST_WR_DATE) + +struct spear_rtc_config { + struct rtc_device *rtc; + struct clk *clk; + spinlock_t lock; + void __iomem *ioaddr; + unsigned int irq_wake; +}; + +static inline void spear_rtc_clear_interrupt(struct spear_rtc_config *config) +{ + unsigned int val; + unsigned long flags; + + spin_lock_irqsave(&config->lock, flags); + val = readl(config->ioaddr + STATUS_REG); + val |= RTC_INT_MASK; + writel(val, config->ioaddr + STATUS_REG); + spin_unlock_irqrestore(&config->lock, flags); +} + +static inline void spear_rtc_enable_interrupt(struct spear_rtc_config *config) +{ + unsigned int val; + + val = readl(config->ioaddr + CTRL_REG); + if (!(val & INT_ENABLE)) { + spear_rtc_clear_interrupt(config); + val |= INT_ENABLE; + writel(val, config->ioaddr + CTRL_REG); + } +} + +static inline void spear_rtc_disable_interrupt(struct spear_rtc_config *config) +{ + unsigned int val; + + val = readl(config->ioaddr + CTRL_REG); + if (val & INT_ENABLE) { + val &= ~INT_ENABLE; + writel(val, config->ioaddr + CTRL_REG); + } +} + +static inline int is_write_complete(struct spear_rtc_config *config) +{ + int ret = 0; + unsigned long flags; + + spin_lock_irqsave(&config->lock, flags); + if ((readl(config->ioaddr + STATUS_REG)) & STATUS_FAIL) + ret = -EIO; + spin_unlock_irqrestore(&config->lock, flags); + + return ret; +} + +static void rtc_wait_not_busy(struct spear_rtc_config *config) +{ + int status, count = 0; + unsigned long flags; + + /* Assuming BUSY may stay active for 80 msec) */ + for (count = 0; count < 80; count++) { + spin_lock_irqsave(&config->lock, flags); + status = readl(config->ioaddr + STATUS_REG); + spin_unlock_irqrestore(&config->lock, flags); + if ((status & STATUS_BUSY) == 0) + break; + /* check status busy, after each msec */ + msleep(1); + } +} + +static irqreturn_t spear_rtc_irq(int irq, void *dev_id) +{ + struct spear_rtc_config *config = dev_id; + unsigned long events = 0; + unsigned int irq_data; + + spin_lock(&config->lock); + irq_data = readl(config->ioaddr + STATUS_REG); + spin_unlock(&config->lock); + + if ((irq_data & RTC_INT_MASK)) { + spear_rtc_clear_interrupt(config); + events = RTC_IRQF | RTC_AF; + rtc_update_irq(config->rtc, 1, events); + return IRQ_HANDLED; + } else + return IRQ_NONE; + +} + +static void tm2bcd(struct rtc_time *tm) +{ + tm->tm_sec = bin2bcd(tm->tm_sec); + tm->tm_min = bin2bcd(tm->tm_min); + tm->tm_hour = bin2bcd(tm->tm_hour); + tm->tm_mday = bin2bcd(tm->tm_mday); + tm->tm_mon = bin2bcd(tm->tm_mon + 1); + tm->tm_year = bin2bcd(tm->tm_year); +} + +static void bcd2tm(struct rtc_time *tm) +{ + tm->tm_sec = bcd2bin(tm->tm_sec); + tm->tm_min = bcd2bin(tm->tm_min); + tm->tm_hour = bcd2bin(tm->tm_hour); + tm->tm_mday = bcd2bin(tm->tm_mday); + tm->tm_mon = bcd2bin(tm->tm_mon) - 1; + /* epoch == 1900 */ + tm->tm_year = bcd2bin(tm->tm_year); +} + +/* + * spear_rtc_read_time - set the time + * @dev: rtc device in use + * @tm: holds date and time + * + * This function read time and date. On success it will return 0 + * otherwise -ve error is returned. + */ +static int spear_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct spear_rtc_config *config = dev_get_drvdata(dev); + unsigned int time, date; + + /* we don't report wday/yday/isdst ... */ + rtc_wait_not_busy(config); + + do { + time = readl(config->ioaddr + TIME_REG); + date = readl(config->ioaddr + DATE_REG); + } while (time == readl(config->ioaddr + TIME_REG)); + tm->tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK; + tm->tm_min = (time >> MINUTE_SHIFT) & MIN_MASK; + tm->tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK; + tm->tm_mday = (date >> MDAY_SHIFT) & DAY_MASK; + tm->tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK; + tm->tm_year = (date >> YEAR_SHIFT) & YEAR_MASK; + + bcd2tm(tm); + return 0; +} + +/* + * spear_rtc_set_time - set the time + * @dev: rtc device in use + * @tm: holds date and time + * + * This function set time and date. On success it will return 0 + * otherwise -ve error is returned. + */ +static int spear_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct spear_rtc_config *config = dev_get_drvdata(dev); + unsigned int time, date; + + tm2bcd(tm); + + rtc_wait_not_busy(config); + time = (tm->tm_sec << SECOND_SHIFT) | (tm->tm_min << MINUTE_SHIFT) | + (tm->tm_hour << HOUR_SHIFT); + date = (tm->tm_mday << MDAY_SHIFT) | (tm->tm_mon << MONTH_SHIFT) | + (tm->tm_year << YEAR_SHIFT); + writel(time, config->ioaddr + TIME_REG); + writel(date, config->ioaddr + DATE_REG); + + return is_write_complete(config); +} + +/* + * spear_rtc_read_alarm - read the alarm time + * @dev: rtc device in use + * @alm: holds alarm date and time + * + * This function read alarm time and date. On success it will return 0 + * otherwise -ve error is returned. + */ +static int spear_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) +{ + struct spear_rtc_config *config = dev_get_drvdata(dev); + unsigned int time, date; + + rtc_wait_not_busy(config); + + time = readl(config->ioaddr + ALARM_TIME_REG); + date = readl(config->ioaddr + ALARM_DATE_REG); + alm->time.tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK; + alm->time.tm_min = (time >> MINUTE_SHIFT) & MIN_MASK; + alm->time.tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK; + alm->time.tm_mday = (date >> MDAY_SHIFT) & DAY_MASK; + alm->time.tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK; + alm->time.tm_year = (date >> YEAR_SHIFT) & YEAR_MASK; + + bcd2tm(&alm->time); + alm->enabled = readl(config->ioaddr + CTRL_REG) & INT_ENABLE; + + return 0; +} + +/* + * spear_rtc_set_alarm - set the alarm time + * @dev: rtc device in use + * @alm: holds alarm date and time + * + * This function set alarm time and date. On success it will return 0 + * otherwise -ve error is returned. + */ +static int spear_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) +{ + struct spear_rtc_config *config = dev_get_drvdata(dev); + unsigned int time, date; + int err; + + tm2bcd(&alm->time); + + rtc_wait_not_busy(config); + + time = (alm->time.tm_sec << SECOND_SHIFT) | (alm->time.tm_min << + MINUTE_SHIFT) | (alm->time.tm_hour << HOUR_SHIFT); + date = (alm->time.tm_mday << MDAY_SHIFT) | (alm->time.tm_mon << + MONTH_SHIFT) | (alm->time.tm_year << YEAR_SHIFT); + + writel(time, config->ioaddr + ALARM_TIME_REG); + writel(date, config->ioaddr + ALARM_DATE_REG); + err = is_write_complete(config); + if (err < 0) + return err; + + if (alm->enabled) + spear_rtc_enable_interrupt(config); + else + spear_rtc_disable_interrupt(config); + + return 0; +} + +static int spear_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct spear_rtc_config *config = dev_get_drvdata(dev); + int ret = 0; + + spear_rtc_clear_interrupt(config); + + switch (enabled) { + case 0: + /* alarm off */ + spear_rtc_disable_interrupt(config); + break; + case 1: + /* alarm on */ + spear_rtc_enable_interrupt(config); + break; + default: + ret = -EINVAL; + break; + } + + return ret; +} + +static const struct rtc_class_ops spear_rtc_ops = { + .read_time = spear_rtc_read_time, + .set_time = spear_rtc_set_time, + .read_alarm = spear_rtc_read_alarm, + .set_alarm = spear_rtc_set_alarm, + .alarm_irq_enable = spear_alarm_irq_enable, +}; + +static int spear_rtc_probe(struct platform_device *pdev) +{ + struct spear_rtc_config *config; + int status = 0; + int irq; + + config = devm_kzalloc(&pdev->dev, sizeof(*config), GFP_KERNEL); + if (!config) + return -ENOMEM; + + config->rtc = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(config->rtc)) + return PTR_ERR(config->rtc); + + /* alarm irqs */ + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + + status = devm_request_irq(&pdev->dev, irq, spear_rtc_irq, 0, pdev->name, + config); + if (status) { + dev_err(&pdev->dev, "Alarm interrupt IRQ%d already claimed\n", + irq); + return status; + } + + config->ioaddr = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(config->ioaddr)) + return PTR_ERR(config->ioaddr); + + config->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(config->clk)) + return PTR_ERR(config->clk); + + status = clk_prepare_enable(config->clk); + if (status < 0) + return status; + + spin_lock_init(&config->lock); + platform_set_drvdata(pdev, config); + + config->rtc->ops = &spear_rtc_ops; + config->rtc->range_min = RTC_TIMESTAMP_BEGIN_0000; + config->rtc->range_max = RTC_TIMESTAMP_END_9999; + + status = devm_rtc_register_device(config->rtc); + if (status) + goto err_disable_clock; + + if (!device_can_wakeup(&pdev->dev)) + device_init_wakeup(&pdev->dev, true); + + return 0; + +err_disable_clock: + clk_disable_unprepare(config->clk); + + return status; +} + +static void spear_rtc_remove(struct platform_device *pdev) +{ + struct spear_rtc_config *config = platform_get_drvdata(pdev); + + spear_rtc_disable_interrupt(config); + clk_disable_unprepare(config->clk); + device_init_wakeup(&pdev->dev, false); +} + +#ifdef CONFIG_PM_SLEEP +static int spear_rtc_suspend(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct spear_rtc_config *config = platform_get_drvdata(pdev); + int irq; + + irq = platform_get_irq(pdev, 0); + if (device_may_wakeup(&pdev->dev)) { + if (!enable_irq_wake(irq)) + config->irq_wake = 1; + } else { + spear_rtc_disable_interrupt(config); + clk_disable(config->clk); + } + + return 0; +} + +static int spear_rtc_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct spear_rtc_config *config = platform_get_drvdata(pdev); + int irq; + + irq = platform_get_irq(pdev, 0); + + if (device_may_wakeup(&pdev->dev)) { + if (config->irq_wake) { + disable_irq_wake(irq); + config->irq_wake = 0; + } + } else { + clk_enable(config->clk); + spear_rtc_enable_interrupt(config); + } + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(spear_rtc_pm_ops, spear_rtc_suspend, spear_rtc_resume); + +static void spear_rtc_shutdown(struct platform_device *pdev) +{ + struct spear_rtc_config *config = platform_get_drvdata(pdev); + + spear_rtc_disable_interrupt(config); + clk_disable(config->clk); +} + +#ifdef CONFIG_OF +static const struct of_device_id spear_rtc_id_table[] = { + { .compatible = "st,spear600-rtc" }, + {} +}; +MODULE_DEVICE_TABLE(of, spear_rtc_id_table); +#endif + +static struct platform_driver spear_rtc_driver = { + .probe = spear_rtc_probe, + .remove = spear_rtc_remove, + .shutdown = spear_rtc_shutdown, + .driver = { + .name = "rtc-spear", + .pm = &spear_rtc_pm_ops, + .of_match_table = of_match_ptr(spear_rtc_id_table), + }, +}; + +module_platform_driver(spear_rtc_driver); + +MODULE_ALIAS("platform:rtc-spear"); +MODULE_AUTHOR("Rajeev Kumar "); +MODULE_DESCRIPTION("ST SPEAr Realtime Clock Driver (RTC)"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1