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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /drivers/rtc/rtc-max8925.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'drivers/rtc/rtc-max8925.c')
-rw-r--r--drivers/rtc/rtc-max8925.c322
1 files changed, 322 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-max8925.c b/drivers/rtc/rtc-max8925.c
new file mode 100644
index 000000000..6ce8afbea
--- /dev/null
+++ b/drivers/rtc/rtc-max8925.c
@@ -0,0 +1,322 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * RTC driver for Maxim MAX8925
+ *
+ * Copyright (C) 2009-2010 Marvell International Ltd.
+ * Haojian Zhuang <haojian.zhuang@marvell.com>
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/rtc.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/max8925.h>
+
+enum {
+ RTC_SEC = 0,
+ RTC_MIN,
+ RTC_HOUR,
+ RTC_WEEKDAY,
+ RTC_DATE,
+ RTC_MONTH,
+ RTC_YEAR1,
+ RTC_YEAR2,
+};
+
+#define MAX8925_RTC_SEC 0x00
+#define MAX8925_RTC_MIN 0x01
+#define MAX8925_RTC_HOUR 0x02
+#define MAX8925_RTC_WEEKDAY 0x03
+#define MAX8925_RTC_DATE 0x04
+#define MAX8925_RTC_MONTH 0x05
+#define MAX8925_RTC_YEAR1 0x06
+#define MAX8925_RTC_YEAR2 0x07
+#define MAX8925_ALARM0_SEC 0x08
+#define MAX8925_ALARM0_MIN 0x09
+#define MAX8925_ALARM0_HOUR 0x0a
+#define MAX8925_ALARM0_WEEKDAY 0x0b
+#define MAX8925_ALARM0_DATE 0x0c
+#define MAX8925_ALARM0_MON 0x0d
+#define MAX8925_ALARM0_YEAR1 0x0e
+#define MAX8925_ALARM0_YEAR2 0x0f
+#define MAX8925_ALARM1_SEC 0x10
+#define MAX8925_ALARM1_MIN 0x11
+#define MAX8925_ALARM1_HOUR 0x12
+#define MAX8925_ALARM1_WEEKDAY 0x13
+#define MAX8925_ALARM1_DATE 0x14
+#define MAX8925_ALARM1_MON 0x15
+#define MAX8925_ALARM1_YEAR1 0x16
+#define MAX8925_ALARM1_YEAR2 0x17
+#define MAX8925_RTC_CNTL 0x1b
+#define MAX8925_RTC_STATUS 0x20
+
+#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 max8925_rtc_info {
+ struct rtc_device *rtc_dev;
+ struct max8925_chip *chip;
+ struct i2c_client *rtc;
+ struct device *dev;
+ int irq;
+};
+
+static irqreturn_t rtc_update_handler(int irq, void *data)
+{
+ struct max8925_rtc_info *info = (struct max8925_rtc_info *)data;
+
+ /* disable ALARM0 except for 1SEC alarm */
+ max8925_set_bits(info->rtc, MAX8925_ALARM0_CNTL, 0x7f, 0);
+ rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);
+ return IRQ_HANDLED;
+}
+
+static int tm_calc(struct rtc_time *tm, unsigned char *buf, int len)
+{
+ if (len < TIME_NUM)
+ return -EINVAL;
+ tm->tm_year = (buf[RTC_YEAR2] >> 4) * 1000
+ + (buf[RTC_YEAR2] & 0xf) * 100
+ + (buf[RTC_YEAR1] >> 4) * 10
+ + (buf[RTC_YEAR1] & 0xf);
+ tm->tm_year -= 1900;
+ tm->tm_mon = ((buf[RTC_MONTH] >> 4) & 0x01) * 10
+ + (buf[RTC_MONTH] & 0x0f);
+ tm->tm_mday = ((buf[RTC_DATE] >> 4) & 0x03) * 10
+ + (buf[RTC_DATE] & 0x0f);
+ tm->tm_wday = buf[RTC_WEEKDAY] & 0x07;
+ if (buf[RTC_HOUR] & HOUR_12) {
+ tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x1) * 10
+ + (buf[RTC_HOUR] & 0x0f);
+ if (buf[RTC_HOUR] & HOUR_AM_PM)
+ tm->tm_hour += 12;
+ } else
+ tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x03) * 10
+ + (buf[RTC_HOUR] & 0x0f);
+ tm->tm_min = ((buf[RTC_MIN] >> 4) & 0x7) * 10
+ + (buf[RTC_MIN] & 0x0f);
+ tm->tm_sec = ((buf[RTC_SEC] >> 4) & 0x7) * 10
+ + (buf[RTC_SEC] & 0x0f);
+ return 0;
+}
+
+static int data_calc(unsigned char *buf, struct rtc_time *tm, int len)
+{
+ unsigned char high, low;
+
+ if (len < TIME_NUM)
+ return -EINVAL;
+
+ high = (tm->tm_year + 1900) / 1000;
+ low = (tm->tm_year + 1900) / 100;
+ low = low - high * 10;
+ buf[RTC_YEAR2] = (high << 4) + low;
+ high = (tm->tm_year + 1900) / 10;
+ low = tm->tm_year + 1900;
+ low = low - high * 10;
+ high = high - (high / 10) * 10;
+ buf[RTC_YEAR1] = (high << 4) + low;
+ high = tm->tm_mon / 10;
+ low = tm->tm_mon;
+ low = low - high * 10;
+ buf[RTC_MONTH] = (high << 4) + low;
+ high = tm->tm_mday / 10;
+ low = tm->tm_mday;
+ low = low - high * 10;
+ buf[RTC_DATE] = (high << 4) + low;
+ buf[RTC_WEEKDAY] = tm->tm_wday;
+ high = tm->tm_hour / 10;
+ low = tm->tm_hour;
+ low = low - high * 10;
+ buf[RTC_HOUR] = (high << 4) + low;
+ high = tm->tm_min / 10;
+ low = tm->tm_min;
+ low = low - high * 10;
+ buf[RTC_MIN] = (high << 4) + low;
+ high = tm->tm_sec / 10;
+ low = tm->tm_sec;
+ low = low - high * 10;
+ buf[RTC_SEC] = (high << 4) + low;
+ return 0;
+}
+
+static int max8925_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct max8925_rtc_info *info = dev_get_drvdata(dev);
+ unsigned char buf[TIME_NUM];
+ int ret;
+
+ ret = max8925_bulk_read(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf);
+ if (ret < 0)
+ goto out;
+ ret = tm_calc(tm, buf, TIME_NUM);
+out:
+ return ret;
+}
+
+static int max8925_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct max8925_rtc_info *info = dev_get_drvdata(dev);
+ unsigned char buf[TIME_NUM];
+ int ret;
+
+ ret = data_calc(buf, tm, TIME_NUM);
+ if (ret < 0)
+ goto out;
+ ret = max8925_bulk_write(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf);
+out:
+ return ret;
+}
+
+static int max8925_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct max8925_rtc_info *info = dev_get_drvdata(dev);
+ unsigned char buf[TIME_NUM];
+ int ret;
+
+ ret = max8925_bulk_read(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf);
+ if (ret < 0)
+ goto out;
+ ret = tm_calc(&alrm->time, buf, TIME_NUM);
+ if (ret < 0)
+ goto out;
+ ret = max8925_reg_read(info->rtc, MAX8925_RTC_IRQ_MASK);
+ if (ret < 0)
+ goto out;
+ if (ret & ALARM0_IRQ) {
+ alrm->enabled = 0;
+ } else {
+ ret = max8925_reg_read(info->rtc, MAX8925_ALARM0_CNTL);
+ if (ret < 0)
+ goto out;
+ if (!ret)
+ alrm->enabled = 0;
+ else
+ alrm->enabled = 1;
+ }
+ ret = max8925_reg_read(info->rtc, MAX8925_RTC_STATUS);
+ if (ret < 0)
+ goto out;
+ if (ret & ALARM0_STATUS)
+ alrm->pending = 1;
+ else
+ alrm->pending = 0;
+ return 0;
+out:
+ return ret;
+}
+
+static int max8925_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct max8925_rtc_info *info = dev_get_drvdata(dev);
+ unsigned char buf[TIME_NUM];
+ int ret;
+
+ ret = data_calc(buf, &alrm->time, TIME_NUM);
+ if (ret < 0)
+ goto out;
+ ret = max8925_bulk_write(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf);
+ if (ret < 0)
+ goto out;
+ if (alrm->enabled)
+ /* only enable alarm on year/month/day/hour/min/sec */
+ ret = max8925_reg_write(info->rtc, MAX8925_ALARM0_CNTL, 0x77);
+ else
+ ret = max8925_reg_write(info->rtc, MAX8925_ALARM0_CNTL, 0x0);
+out:
+ return ret;
+}
+
+static const struct rtc_class_ops max8925_rtc_ops = {
+ .read_time = max8925_rtc_read_time,
+ .set_time = max8925_rtc_set_time,
+ .read_alarm = max8925_rtc_read_alarm,
+ .set_alarm = max8925_rtc_set_alarm,
+};
+
+static int max8925_rtc_probe(struct platform_device *pdev)
+{
+ struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
+ struct max8925_rtc_info *info;
+ int ret;
+
+ info = devm_kzalloc(&pdev->dev, sizeof(struct max8925_rtc_info),
+ GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+ info->chip = chip;
+ info->rtc = chip->rtc;
+ info->dev = &pdev->dev;
+ info->irq = platform_get_irq(pdev, 0);
+
+ ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL,
+ rtc_update_handler, IRQF_ONESHOT,
+ "rtc-alarm0", info);
+ if (ret < 0) {
+ dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
+ info->irq, ret);
+ return ret;
+ }
+
+ dev_set_drvdata(&pdev->dev, info);
+ /* XXX - isn't this redundant? */
+ platform_set_drvdata(pdev, info);
+
+ device_init_wakeup(&pdev->dev, true);
+
+ info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8925-rtc",
+ &max8925_rtc_ops, THIS_MODULE);
+ ret = PTR_ERR(info->rtc_dev);
+ if (IS_ERR(info->rtc_dev)) {
+ dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int max8925_rtc_suspend(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
+
+ if (device_may_wakeup(dev))
+ chip->wakeup_flag |= 1 << MAX8925_IRQ_RTC_ALARM0;
+ return 0;
+}
+static int max8925_rtc_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
+
+ if (device_may_wakeup(dev))
+ chip->wakeup_flag &= ~(1 << MAX8925_IRQ_RTC_ALARM0);
+ return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(max8925_rtc_pm_ops, max8925_rtc_suspend, max8925_rtc_resume);
+
+static struct platform_driver max8925_rtc_driver = {
+ .driver = {
+ .name = "max8925-rtc",
+ .pm = &max8925_rtc_pm_ops,
+ },
+ .probe = max8925_rtc_probe,
+};
+
+module_platform_driver(max8925_rtc_driver);
+
+MODULE_DESCRIPTION("Maxim MAX8925 RTC driver");
+MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
+MODULE_LICENSE("GPL");
+