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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-ds1286.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-ds1286.c')
-rw-r--r--drivers/rtc/rtc-ds1286.c358
1 files changed, 358 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-ds1286.c b/drivers/rtc/rtc-ds1286.c
new file mode 100644
index 000000000..7acf849d4
--- /dev/null
+++ b/drivers/rtc/rtc-ds1286.c
@@ -0,0 +1,358 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * DS1286 Real Time Clock interface for Linux
+ *
+ * Copyright (C) 1998, 1999, 2000 Ralf Baechle
+ * Copyright (C) 2008 Thomas Bogendoerfer
+ *
+ * Based on code written by Paul Gortmaker.
+ */
+
+#include <linux/module.h>
+#include <linux/rtc.h>
+#include <linux/platform_device.h>
+#include <linux/bcd.h>
+#include <linux/rtc/ds1286.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+
+struct ds1286_priv {
+ struct rtc_device *rtc;
+ u32 __iomem *rtcregs;
+ spinlock_t lock;
+};
+
+static inline u8 ds1286_rtc_read(struct ds1286_priv *priv, int reg)
+{
+ return __raw_readl(&priv->rtcregs[reg]) & 0xff;
+}
+
+static inline void ds1286_rtc_write(struct ds1286_priv *priv, u8 data, int reg)
+{
+ __raw_writel(data, &priv->rtcregs[reg]);
+}
+
+
+static int ds1286_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+ struct ds1286_priv *priv = dev_get_drvdata(dev);
+ unsigned long flags;
+ unsigned char val;
+
+ /* Allow or mask alarm interrupts */
+ spin_lock_irqsave(&priv->lock, flags);
+ val = ds1286_rtc_read(priv, RTC_CMD);
+ if (enabled)
+ val &= ~RTC_TDM;
+ else
+ val |= RTC_TDM;
+ ds1286_rtc_write(priv, val, RTC_CMD);
+ spin_unlock_irqrestore(&priv->lock, flags);
+
+ return 0;
+}
+
+#ifdef CONFIG_RTC_INTF_DEV
+
+static int ds1286_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+{
+ struct ds1286_priv *priv = dev_get_drvdata(dev);
+ unsigned long flags;
+ unsigned char val;
+
+ switch (cmd) {
+ case RTC_WIE_OFF:
+ /* Mask watchdog int. enab. bit */
+ spin_lock_irqsave(&priv->lock, flags);
+ val = ds1286_rtc_read(priv, RTC_CMD);
+ val |= RTC_WAM;
+ ds1286_rtc_write(priv, val, RTC_CMD);
+ spin_unlock_irqrestore(&priv->lock, flags);
+ break;
+ case RTC_WIE_ON:
+ /* Allow watchdog interrupts. */
+ spin_lock_irqsave(&priv->lock, flags);
+ val = ds1286_rtc_read(priv, RTC_CMD);
+ val &= ~RTC_WAM;
+ ds1286_rtc_write(priv, val, RTC_CMD);
+ spin_unlock_irqrestore(&priv->lock, flags);
+ break;
+ default:
+ return -ENOIOCTLCMD;
+ }
+ return 0;
+}
+
+#else
+#define ds1286_ioctl NULL
+#endif
+
+#ifdef CONFIG_PROC_FS
+
+static int ds1286_proc(struct device *dev, struct seq_file *seq)
+{
+ struct ds1286_priv *priv = dev_get_drvdata(dev);
+ unsigned char month, cmd, amode;
+ const char *s;
+
+ month = ds1286_rtc_read(priv, RTC_MONTH);
+ seq_printf(seq,
+ "oscillator\t: %s\n"
+ "square_wave\t: %s\n",
+ (month & RTC_EOSC) ? "disabled" : "enabled",
+ (month & RTC_ESQW) ? "disabled" : "enabled");
+
+ amode = ((ds1286_rtc_read(priv, RTC_MINUTES_ALARM) & 0x80) >> 5) |
+ ((ds1286_rtc_read(priv, RTC_HOURS_ALARM) & 0x80) >> 6) |
+ ((ds1286_rtc_read(priv, RTC_DAY_ALARM) & 0x80) >> 7);
+ switch (amode) {
+ case 7:
+ s = "each minute";
+ break;
+ case 3:
+ s = "minutes match";
+ break;
+ case 1:
+ s = "hours and minutes match";
+ break;
+ case 0:
+ s = "days, hours and minutes match";
+ break;
+ default:
+ s = "invalid";
+ break;
+ }
+ seq_printf(seq, "alarm_mode\t: %s\n", s);
+
+ cmd = ds1286_rtc_read(priv, RTC_CMD);
+ seq_printf(seq,
+ "alarm_enable\t: %s\n"
+ "wdog_alarm\t: %s\n"
+ "alarm_mask\t: %s\n"
+ "wdog_alarm_mask\t: %s\n"
+ "interrupt_mode\t: %s\n"
+ "INTB_mode\t: %s_active\n"
+ "interrupt_pins\t: %s\n",
+ (cmd & RTC_TDF) ? "yes" : "no",
+ (cmd & RTC_WAF) ? "yes" : "no",
+ (cmd & RTC_TDM) ? "disabled" : "enabled",
+ (cmd & RTC_WAM) ? "disabled" : "enabled",
+ (cmd & RTC_PU_LVL) ? "pulse" : "level",
+ (cmd & RTC_IBH_LO) ? "low" : "high",
+ (cmd & RTC_IPSW) ? "unswapped" : "swapped");
+ return 0;
+}
+
+#else
+#define ds1286_proc NULL
+#endif
+
+static int ds1286_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct ds1286_priv *priv = dev_get_drvdata(dev);
+ unsigned char save_control;
+ unsigned long flags;
+ unsigned long uip_watchdog = jiffies;
+
+ /*
+ * read RTC once any update in progress is done. The update
+ * can take just over 2ms. We wait 10 to 20ms. There is no need to
+ * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
+ * If you need to know *exactly* when a second has started, enable
+ * periodic update complete interrupts, (via ioctl) and then
+ * immediately read /dev/rtc which will block until you get the IRQ.
+ * Once the read clears, read the RTC time (again via ioctl). Easy.
+ */
+
+ if (ds1286_rtc_read(priv, RTC_CMD) & RTC_TE)
+ while (time_before(jiffies, uip_watchdog + 2*HZ/100))
+ barrier();
+
+ /*
+ * Only the values that we read from the RTC are set. We leave
+ * tm_wday, tm_yday and tm_isdst untouched. Even though the
+ * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
+ * by the RTC when initially set to a non-zero value.
+ */
+ spin_lock_irqsave(&priv->lock, flags);
+ save_control = ds1286_rtc_read(priv, RTC_CMD);
+ ds1286_rtc_write(priv, (save_control|RTC_TE), RTC_CMD);
+
+ tm->tm_sec = ds1286_rtc_read(priv, RTC_SECONDS);
+ tm->tm_min = ds1286_rtc_read(priv, RTC_MINUTES);
+ tm->tm_hour = ds1286_rtc_read(priv, RTC_HOURS) & 0x3f;
+ tm->tm_mday = ds1286_rtc_read(priv, RTC_DATE);
+ tm->tm_mon = ds1286_rtc_read(priv, RTC_MONTH) & 0x1f;
+ tm->tm_year = ds1286_rtc_read(priv, RTC_YEAR);
+
+ ds1286_rtc_write(priv, save_control, RTC_CMD);
+ spin_unlock_irqrestore(&priv->lock, flags);
+
+ 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);
+ tm->tm_year = bcd2bin(tm->tm_year);
+
+ /*
+ * Account for differences between how the RTC uses the values
+ * and how they are defined in a struct rtc_time;
+ */
+ if (tm->tm_year < 45)
+ tm->tm_year += 30;
+ tm->tm_year += 40;
+ if (tm->tm_year < 70)
+ tm->tm_year += 100;
+
+ tm->tm_mon--;
+
+ return 0;
+}
+
+static int ds1286_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct ds1286_priv *priv = dev_get_drvdata(dev);
+ unsigned char mon, day, hrs, min, sec;
+ unsigned char save_control;
+ unsigned int yrs;
+ unsigned long flags;
+
+ yrs = tm->tm_year + 1900;
+ mon = tm->tm_mon + 1; /* tm_mon starts at zero */
+ day = tm->tm_mday;
+ hrs = tm->tm_hour;
+ min = tm->tm_min;
+ sec = tm->tm_sec;
+
+ if (yrs < 1970)
+ return -EINVAL;
+
+ yrs -= 1940;
+ if (yrs > 255) /* They are unsigned */
+ return -EINVAL;
+
+ if (yrs >= 100)
+ yrs -= 100;
+
+ sec = bin2bcd(sec);
+ min = bin2bcd(min);
+ hrs = bin2bcd(hrs);
+ day = bin2bcd(day);
+ mon = bin2bcd(mon);
+ yrs = bin2bcd(yrs);
+
+ spin_lock_irqsave(&priv->lock, flags);
+ save_control = ds1286_rtc_read(priv, RTC_CMD);
+ ds1286_rtc_write(priv, (save_control|RTC_TE), RTC_CMD);
+
+ ds1286_rtc_write(priv, yrs, RTC_YEAR);
+ ds1286_rtc_write(priv, mon, RTC_MONTH);
+ ds1286_rtc_write(priv, day, RTC_DATE);
+ ds1286_rtc_write(priv, hrs, RTC_HOURS);
+ ds1286_rtc_write(priv, min, RTC_MINUTES);
+ ds1286_rtc_write(priv, sec, RTC_SECONDS);
+ ds1286_rtc_write(priv, 0, RTC_HUNDREDTH_SECOND);
+
+ ds1286_rtc_write(priv, save_control, RTC_CMD);
+ spin_unlock_irqrestore(&priv->lock, flags);
+ return 0;
+}
+
+static int ds1286_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+ struct ds1286_priv *priv = dev_get_drvdata(dev);
+ unsigned long flags;
+
+ /*
+ * Only the values that we read from the RTC are set. That
+ * means only tm_wday, tm_hour, tm_min.
+ */
+ spin_lock_irqsave(&priv->lock, flags);
+ alm->time.tm_min = ds1286_rtc_read(priv, RTC_MINUTES_ALARM) & 0x7f;
+ alm->time.tm_hour = ds1286_rtc_read(priv, RTC_HOURS_ALARM) & 0x1f;
+ alm->time.tm_wday = ds1286_rtc_read(priv, RTC_DAY_ALARM) & 0x07;
+ ds1286_rtc_read(priv, RTC_CMD);
+ spin_unlock_irqrestore(&priv->lock, flags);
+
+ alm->time.tm_min = bcd2bin(alm->time.tm_min);
+ alm->time.tm_hour = bcd2bin(alm->time.tm_hour);
+ alm->time.tm_sec = 0;
+ return 0;
+}
+
+static int ds1286_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+ struct ds1286_priv *priv = dev_get_drvdata(dev);
+ unsigned char hrs, min, sec;
+
+ hrs = alm->time.tm_hour;
+ min = alm->time.tm_min;
+ sec = alm->time.tm_sec;
+
+ if (hrs >= 24)
+ hrs = 0xff;
+
+ if (min >= 60)
+ min = 0xff;
+
+ if (sec != 0)
+ return -EINVAL;
+
+ min = bin2bcd(min);
+ hrs = bin2bcd(hrs);
+
+ spin_lock(&priv->lock);
+ ds1286_rtc_write(priv, hrs, RTC_HOURS_ALARM);
+ ds1286_rtc_write(priv, min, RTC_MINUTES_ALARM);
+ spin_unlock(&priv->lock);
+
+ return 0;
+}
+
+static const struct rtc_class_ops ds1286_ops = {
+ .ioctl = ds1286_ioctl,
+ .proc = ds1286_proc,
+ .read_time = ds1286_read_time,
+ .set_time = ds1286_set_time,
+ .read_alarm = ds1286_read_alarm,
+ .set_alarm = ds1286_set_alarm,
+ .alarm_irq_enable = ds1286_alarm_irq_enable,
+};
+
+static int ds1286_probe(struct platform_device *pdev)
+{
+ struct rtc_device *rtc;
+ struct ds1286_priv *priv;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(struct ds1286_priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->rtcregs = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(priv->rtcregs))
+ return PTR_ERR(priv->rtcregs);
+
+ spin_lock_init(&priv->lock);
+ platform_set_drvdata(pdev, priv);
+ rtc = devm_rtc_device_register(&pdev->dev, "ds1286", &ds1286_ops,
+ THIS_MODULE);
+ if (IS_ERR(rtc))
+ return PTR_ERR(rtc);
+ priv->rtc = rtc;
+ return 0;
+}
+
+static struct platform_driver ds1286_platform_driver = {
+ .driver = {
+ .name = "rtc-ds1286",
+ },
+ .probe = ds1286_probe,
+};
+
+module_platform_driver(ds1286_platform_driver);
+
+MODULE_AUTHOR("Thomas Bogendoerfer <tsbogend@alpha.franken.de>");
+MODULE_DESCRIPTION("DS1286 RTC driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:rtc-ds1286");