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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-09-20 08:15:23 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-09-20 08:15:23 -0700 |
| commit | bdab18633a302c82b5e5d5dbc4e38b0baf9c0837 (patch) | |
| tree | 0446500af9a76d4e8b2a72a0a41391ceede73a10 /drivers/rtc/rtc-88pm886.c | |
| download | linux-stable-bdab18633a302c82b5e5d5dbc4e38b0baf9c0837.tar.gz linux-stable-bdab18633a302c82b5e5d5dbc4e38b0baf9c0837.zip | |
Merge tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipgrafted
Pull futex fix from Ingo Molnar:
- Also allocate a default private futex hash on vfork() as well, to
avoid races with (private) futex waiters (Peter Zijlstra)
* tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
futex: Also allocate private hash on vfork()
Diffstat (limited to 'drivers/rtc/rtc-88pm886.c')
| -rw-r--r-- | drivers/rtc/rtc-88pm886.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-88pm886.c b/drivers/rtc/rtc-88pm886.c new file mode 100644 index 000000000..71443ae1b --- /dev/null +++ b/drivers/rtc/rtc-88pm886.c @@ -0,0 +1,96 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <linux/limits.h> +#include <linux/platform_device.h> +#include <linux/rtc.h> + +#include <linux/mfd/88pm886.h> + +/* + * Time is calculated as the sum of a 32-bit read-only advancing counter and a + * writeable constant offset stored in the chip's spare registers. + */ + +static int pm886_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct regmap *regmap = dev_get_drvdata(dev); + u32 time; + u32 buf; + int ret; + + ret = regmap_bulk_read(regmap, PM886_REG_RTC_SPARE1, &buf, 4); + if (ret) + return ret; + time = buf; + + ret = regmap_bulk_read(regmap, PM886_REG_RTC_CNT1, &buf, 4); + if (ret) + return ret; + time += buf; + + rtc_time64_to_tm(time, tm); + + return 0; +} + +static int pm886_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct regmap *regmap = dev_get_drvdata(dev); + u32 buf; + int ret; + + ret = regmap_bulk_read(regmap, PM886_REG_RTC_CNT1, &buf, 4); + if (ret) + return ret; + + buf = rtc_tm_to_time64(tm) - buf; + + return regmap_bulk_write(regmap, PM886_REG_RTC_SPARE1, &buf, 4); +} + +static const struct rtc_class_ops pm886_rtc_ops = { + .read_time = pm886_rtc_read_time, + .set_time = pm886_rtc_set_time, +}; + +static int pm886_rtc_probe(struct platform_device *pdev) +{ + struct pm886_chip *chip = dev_get_drvdata(pdev->dev.parent); + struct device *dev = &pdev->dev; + struct rtc_device *rtc; + int ret; + + platform_set_drvdata(pdev, chip->regmap); + + rtc = devm_rtc_allocate_device(dev); + if (IS_ERR(rtc)) + return dev_err_probe(dev, PTR_ERR(rtc), + "Failed to allocate RTC device\n"); + + rtc->ops = &pm886_rtc_ops; + rtc->range_max = U32_MAX; + + ret = devm_rtc_register_device(rtc); + if (ret) + return dev_err_probe(dev, ret, "Failed to register RTC device\n"); + + return 0; +} + +static const struct platform_device_id pm886_rtc_id_table[] = { + { .name = "88pm886-rtc" }, + { } +}; +MODULE_DEVICE_TABLE(platform, pm886_rtc_id_table); + +static struct platform_driver pm886_rtc_driver = { + .driver = { + .name = "88pm886-rtc", + }, + .probe = pm886_rtc_probe, + .id_table = pm886_rtc_id_table, +}; +module_platform_driver(pm886_rtc_driver); + +MODULE_DESCRIPTION("Marvell 88PM886 RTC driver"); +MODULE_AUTHOR("Karel Balej <balejk@matfyz.cz>"); +MODULE_LICENSE("GPL"); |
