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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-max8907.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-max8907.c')
-rw-r--r--drivers/rtc/rtc-max8907.c220
1 files changed, 220 insertions, 0 deletions
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 <linux/bcd.h>
+#include <linux/mfd/max8907.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/rtc.h>
+#include <linux/slab.h>
+
+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");