From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001 From: Zeng Chi Date: Mon, 21 Sep 2026 18:24:42 +0800 Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson Cc: David Ballesteros Signed-off-by: Zeng Chi Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson --- drivers/rtc/rtc-max8907.c | 220 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 220 insertions(+) create mode 100644 drivers/rtc/rtc-max8907.c (limited to 'drivers/rtc/rtc-max8907.c') diff --git a/drivers/rtc/rtc-max8907.c b/drivers/rtc/rtc-max8907.c new file mode 100644 index 000000000..af97140dd --- /dev/null +++ b/drivers/rtc/rtc-max8907.c @@ -0,0 +1,220 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * RTC driver for Maxim MAX8907 + * + * Copyright (c) 2011-2012, NVIDIA Corporation. + * + * Based on drivers/rtc/rtc-max8925.c, + * Copyright (C) 2009-2010 Marvell International Ltd. + */ + +#include +#include +#include +#include +#include +#include +#include + +enum { + RTC_SEC = 0, + RTC_MIN, + RTC_HOUR, + RTC_WEEKDAY, + RTC_DATE, + RTC_MONTH, + RTC_YEAR1, + RTC_YEAR2, +}; + +#define TIME_NUM 8 +#define ALARM_1SEC (1 << 7) +#define HOUR_12 (1 << 7) +#define HOUR_AM_PM (1 << 5) +#define ALARM0_IRQ (1 << 3) +#define ALARM1_IRQ (1 << 2) +#define ALARM0_STATUS (1 << 2) +#define ALARM1_STATUS (1 << 1) + +struct max8907_rtc { + struct max8907 *max8907; + struct regmap *regmap; + struct rtc_device *rtc_dev; + int irq; +}; + +static irqreturn_t max8907_irq_handler(int irq, void *data) +{ + struct max8907_rtc *rtc = data; + + regmap_write(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0); + + rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF); + + return IRQ_HANDLED; +} + +static void regs_to_tm(u8 *regs, struct rtc_time *tm) +{ + tm->tm_year = bcd2bin(regs[RTC_YEAR2]) * 100 + + bcd2bin(regs[RTC_YEAR1]) - 1900; + tm->tm_mon = bcd2bin(regs[RTC_MONTH] & 0x1f) - 1; + tm->tm_mday = bcd2bin(regs[RTC_DATE] & 0x3f); + tm->tm_wday = (regs[RTC_WEEKDAY] & 0x07); + if (regs[RTC_HOUR] & HOUR_12) { + tm->tm_hour = bcd2bin(regs[RTC_HOUR] & 0x01f); + if (tm->tm_hour == 12) + tm->tm_hour = 0; + if (regs[RTC_HOUR] & HOUR_AM_PM) + tm->tm_hour += 12; + } else { + tm->tm_hour = bcd2bin(regs[RTC_HOUR] & 0x03f); + } + tm->tm_min = bcd2bin(regs[RTC_MIN] & 0x7f); + tm->tm_sec = bcd2bin(regs[RTC_SEC] & 0x7f); +} + +static void tm_to_regs(struct rtc_time *tm, u8 *regs) +{ + u8 high, low; + + high = (tm->tm_year + 1900) / 100; + low = tm->tm_year % 100; + regs[RTC_YEAR2] = bin2bcd(high); + regs[RTC_YEAR1] = bin2bcd(low); + regs[RTC_MONTH] = bin2bcd(tm->tm_mon + 1); + regs[RTC_DATE] = bin2bcd(tm->tm_mday); + regs[RTC_WEEKDAY] = tm->tm_wday; + regs[RTC_HOUR] = bin2bcd(tm->tm_hour); + regs[RTC_MIN] = bin2bcd(tm->tm_min); + regs[RTC_SEC] = bin2bcd(tm->tm_sec); +} + +static int max8907_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct max8907_rtc *rtc = dev_get_drvdata(dev); + u8 regs[TIME_NUM]; + int ret; + + ret = regmap_bulk_read(rtc->regmap, MAX8907_REG_RTC_SEC, regs, + TIME_NUM); + if (ret < 0) + return ret; + + regs_to_tm(regs, tm); + + return 0; +} + +static int max8907_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct max8907_rtc *rtc = dev_get_drvdata(dev); + u8 regs[TIME_NUM]; + + tm_to_regs(tm, regs); + + return regmap_bulk_write(rtc->regmap, MAX8907_REG_RTC_SEC, regs, + TIME_NUM); +} + +static int max8907_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct max8907_rtc *rtc = dev_get_drvdata(dev); + u8 regs[TIME_NUM]; + unsigned int val; + int ret; + + ret = regmap_bulk_read(rtc->regmap, MAX8907_REG_ALARM0_SEC, regs, + TIME_NUM); + if (ret < 0) + return ret; + + regs_to_tm(regs, &alrm->time); + + ret = regmap_read(rtc->regmap, MAX8907_REG_ALARM0_CNTL, &val); + if (ret < 0) + return ret; + + alrm->enabled = !!(val & 0x7f); + + return 0; +} + +static int max8907_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct max8907_rtc *rtc = dev_get_drvdata(dev); + u8 regs[TIME_NUM]; + int ret; + + tm_to_regs(&alrm->time, regs); + + /* Disable alarm while we update the target time */ + ret = regmap_write(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0); + if (ret < 0) + return ret; + + ret = regmap_bulk_write(rtc->regmap, MAX8907_REG_ALARM0_SEC, regs, + TIME_NUM); + if (ret < 0) + return ret; + + if (alrm->enabled) + ret = regmap_write(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0x77); + + return ret; +} + +static const struct rtc_class_ops max8907_rtc_ops = { + .read_time = max8907_rtc_read_time, + .set_time = max8907_rtc_set_time, + .read_alarm = max8907_rtc_read_alarm, + .set_alarm = max8907_rtc_set_alarm, +}; + +static int max8907_rtc_probe(struct platform_device *pdev) +{ + struct max8907 *max8907 = dev_get_drvdata(pdev->dev.parent); + struct max8907_rtc *rtc; + int ret; + + rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); + if (!rtc) + return -ENOMEM; + platform_set_drvdata(pdev, rtc); + + rtc->max8907 = max8907; + rtc->regmap = max8907->regmap_rtc; + + rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8907-rtc", + &max8907_rtc_ops, THIS_MODULE); + if (IS_ERR(rtc->rtc_dev)) { + ret = PTR_ERR(rtc->rtc_dev); + dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret); + return ret; + } + + rtc->irq = regmap_irq_get_virq(max8907->irqc_rtc, + MAX8907_IRQ_RTC_ALARM0); + if (rtc->irq < 0) + return rtc->irq; + + ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL, + max8907_irq_handler, + IRQF_ONESHOT, "max8907-alarm0", rtc); + if (ret < 0) + dev_err(&pdev->dev, "Failed to request IRQ%d: %d\n", + rtc->irq, ret); + + return ret; +} + +static struct platform_driver max8907_rtc_driver = { + .driver = { + .name = "max8907-rtc", + }, + .probe = max8907_rtc_probe, +}; +module_platform_driver(max8907_rtc_driver); + +MODULE_DESCRIPTION("Maxim MAX8907 RTC driver"); +MODULE_LICENSE("GPL v2"); -- cgit v1.3.1