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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-ds1511.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-ds1511.c')
-rw-r--r--drivers/rtc/rtc-ds1511.c368
1 files changed, 368 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-ds1511.c b/drivers/rtc/rtc-ds1511.c
new file mode 100644
index 000000000..8b087d955
--- /dev/null
+++ b/drivers/rtc/rtc-ds1511.c
@@ -0,0 +1,368 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * An rtc driver for the Dallas DS1511
+ *
+ * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
+ * Copyright (C) 2007 Andrew Sharp <andy.sharp@lsi.com>
+ *
+ * Real time clock driver for the Dallas 1511 chip, which also
+ * contains a watchdog timer. There is a tiny amount of code that
+ * platform code could use to mess with the watchdog device a little
+ * bit, but not a full watchdog driver.
+ */
+
+#include <linux/bcd.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/gfp.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/rtc.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/module.h>
+
+#define DS1511_SEC 0x0
+#define DS1511_MIN 0x1
+#define DS1511_HOUR 0x2
+#define DS1511_DOW 0x3
+#define DS1511_DOM 0x4
+#define DS1511_MONTH 0x5
+#define DS1511_YEAR 0x6
+#define DS1511_CENTURY 0x7
+#define DS1511_AM1_SEC 0x8
+#define DS1511_AM2_MIN 0x9
+#define DS1511_AM3_HOUR 0xa
+#define DS1511_AM4_DATE 0xb
+#define DS1511_WD_MSEC 0xc
+#define DS1511_WD_SEC 0xd
+#define DS1511_CONTROL_A 0xe
+#define DS1511_CONTROL_B 0xf
+#define DS1511_RAMADDR_LSB 0x10
+#define DS1511_RAMDATA 0x13
+
+#define DS1511_BLF1 0x80
+#define DS1511_BLF2 0x40
+#define DS1511_PRS 0x20
+#define DS1511_PAB 0x10
+#define DS1511_TDF 0x08
+#define DS1511_KSF 0x04
+#define DS1511_WDF 0x02
+#define DS1511_IRQF 0x01
+#define DS1511_TE 0x80
+#define DS1511_CS 0x40
+#define DS1511_BME 0x20
+#define DS1511_TPE 0x10
+#define DS1511_TIE 0x08
+#define DS1511_KIE 0x04
+#define DS1511_WDE 0x02
+#define DS1511_WDS 0x01
+#define DS1511_RAM_MAX 0x100
+
+struct ds1511_data {
+ struct rtc_device *rtc;
+ void __iomem *ioaddr; /* virtual base address */
+ int irq;
+ spinlock_t lock;
+};
+
+static DEFINE_SPINLOCK(ds1511_lock);
+
+static __iomem char *ds1511_base;
+static u32 reg_spacing = 1;
+
+static void rtc_write(uint8_t val, uint32_t reg)
+{
+ writeb(val, ds1511_base + (reg * reg_spacing));
+}
+
+static uint8_t rtc_read(uint32_t reg)
+{
+ return readb(ds1511_base + (reg * reg_spacing));
+}
+
+static void rtc_disable_update(void)
+{
+ rtc_write((rtc_read(DS1511_CONTROL_B) & ~DS1511_TE), DS1511_CONTROL_B);
+}
+
+static void rtc_enable_update(void)
+{
+ rtc_write((rtc_read(DS1511_CONTROL_B) | DS1511_TE), DS1511_CONTROL_B);
+}
+
+static int ds1511_rtc_set_time(struct device *dev, struct rtc_time *rtc_tm)
+{
+ u8 mon, day, dow, hrs, min, sec, yrs, cen;
+ unsigned long flags;
+
+ yrs = rtc_tm->tm_year % 100;
+ cen = 19 + rtc_tm->tm_year / 100;
+ mon = rtc_tm->tm_mon + 1; /* tm_mon starts at zero */
+ day = rtc_tm->tm_mday;
+ dow = rtc_tm->tm_wday & 0x7; /* automatic BCD */
+ hrs = rtc_tm->tm_hour;
+ min = rtc_tm->tm_min;
+ sec = rtc_tm->tm_sec;
+
+ /*
+ * each register is a different number of valid bits
+ */
+ sec = bin2bcd(sec) & 0x7f;
+ min = bin2bcd(min) & 0x7f;
+ hrs = bin2bcd(hrs) & 0x3f;
+ day = bin2bcd(day) & 0x3f;
+ mon = bin2bcd(mon) & 0x1f;
+ yrs = bin2bcd(yrs) & 0xff;
+ cen = bin2bcd(cen) & 0xff;
+
+ spin_lock_irqsave(&ds1511_lock, flags);
+ rtc_disable_update();
+ rtc_write(cen, DS1511_CENTURY);
+ rtc_write(yrs, DS1511_YEAR);
+ rtc_write((rtc_read(DS1511_MONTH) & 0xe0) | mon, DS1511_MONTH);
+ rtc_write(day, DS1511_DOM);
+ rtc_write(hrs, DS1511_HOUR);
+ rtc_write(min, DS1511_MIN);
+ rtc_write(sec, DS1511_SEC);
+ rtc_write(dow, DS1511_DOW);
+ rtc_enable_update();
+ spin_unlock_irqrestore(&ds1511_lock, flags);
+
+ return 0;
+}
+
+static int ds1511_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
+{
+ unsigned int century;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ds1511_lock, flags);
+ rtc_disable_update();
+
+ rtc_tm->tm_sec = rtc_read(DS1511_SEC) & 0x7f;
+ rtc_tm->tm_min = rtc_read(DS1511_MIN) & 0x7f;
+ rtc_tm->tm_hour = rtc_read(DS1511_HOUR) & 0x3f;
+ rtc_tm->tm_mday = rtc_read(DS1511_DOM) & 0x3f;
+ rtc_tm->tm_wday = rtc_read(DS1511_DOW) & 0x7;
+ rtc_tm->tm_mon = rtc_read(DS1511_MONTH) & 0x1f;
+ rtc_tm->tm_year = rtc_read(DS1511_YEAR) & 0x7f;
+ century = rtc_read(DS1511_CENTURY);
+
+ rtc_enable_update();
+ spin_unlock_irqrestore(&ds1511_lock, flags);
+
+ rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
+ rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
+ rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
+ rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
+ rtc_tm->tm_wday = bcd2bin(rtc_tm->tm_wday);
+ rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
+ rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
+ century = bcd2bin(century) * 100;
+
+ /*
+ * Account for differences between how the RTC uses the values
+ * and how they are defined in a struct rtc_time;
+ */
+ century += rtc_tm->tm_year;
+ rtc_tm->tm_year = century - 1900;
+
+ rtc_tm->tm_mon--;
+
+ return 0;
+}
+
+static void ds1511_rtc_alarm_enable(unsigned int enabled)
+{
+ rtc_write(rtc_read(DS1511_CONTROL_B) | (enabled ? DS1511_TIE : 0), DS1511_CONTROL_B);
+}
+
+static int ds1511_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct ds1511_data *ds1511 = dev_get_drvdata(dev);
+ unsigned long flags;
+
+ spin_lock_irqsave(&ds1511->lock, flags);
+ rtc_write(bin2bcd(alrm->time.tm_mday) & 0x3f, DS1511_AM4_DATE);
+ rtc_write(bin2bcd(alrm->time.tm_hour) & 0x3f, DS1511_AM3_HOUR);
+ rtc_write(bin2bcd(alrm->time.tm_min) & 0x7f, DS1511_AM2_MIN);
+ rtc_write(bin2bcd(alrm->time.tm_sec) & 0x7f, DS1511_AM1_SEC);
+ ds1511_rtc_alarm_enable(alrm->enabled);
+
+ rtc_read(DS1511_CONTROL_A); /* clear interrupts */
+ spin_unlock_irqrestore(&ds1511->lock, flags);
+
+ return 0;
+}
+
+static int ds1511_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ alrm->time.tm_mday = bcd2bin(rtc_read(DS1511_AM4_DATE) & 0x3f);
+ alrm->time.tm_hour = bcd2bin(rtc_read(DS1511_AM3_HOUR) & 0x3f);
+ alrm->time.tm_min = bcd2bin(rtc_read(DS1511_AM2_MIN) & 0x7f);
+ alrm->time.tm_sec = bcd2bin(rtc_read(DS1511_AM1_SEC) & 0x7f);
+ alrm->enabled = !!(rtc_read(DS1511_CONTROL_B) & DS1511_TIE);
+
+ return 0;
+}
+
+static irqreturn_t ds1511_interrupt(int irq, void *dev_id)
+{
+ struct platform_device *pdev = dev_id;
+ struct ds1511_data *ds1511 = platform_get_drvdata(pdev);
+ unsigned long events = 0;
+
+ spin_lock(&ds1511->lock);
+ /*
+ * read and clear interrupt
+ */
+ if (rtc_read(DS1511_CONTROL_A) & DS1511_IRQF) {
+ events = RTC_IRQF | RTC_AF;
+ rtc_update_irq(ds1511->rtc, 1, events);
+ }
+ spin_unlock(&ds1511->lock);
+ return events ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static int ds1511_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+ struct ds1511_data *ds1511 = dev_get_drvdata(dev);
+ unsigned long flags;
+
+ spin_lock_irqsave(&ds1511->lock, flags);
+ ds1511_rtc_alarm_enable(enabled);
+ spin_unlock_irqrestore(&ds1511->lock, flags);
+
+ return 0;
+}
+
+static const struct rtc_class_ops ds1511_rtc_ops = {
+ .read_time = ds1511_rtc_read_time,
+ .set_time = ds1511_rtc_set_time,
+ .read_alarm = ds1511_rtc_read_alarm,
+ .set_alarm = ds1511_rtc_set_alarm,
+ .alarm_irq_enable = ds1511_rtc_alarm_irq_enable,
+};
+
+static int ds1511_nvram_read(void *priv, unsigned int pos, void *buf,
+ size_t size)
+{
+ int i;
+
+ rtc_write(pos, DS1511_RAMADDR_LSB);
+ for (i = 0; i < size; i++)
+ *(char *)buf++ = rtc_read(DS1511_RAMDATA);
+
+ return 0;
+}
+
+static int ds1511_nvram_write(void *priv, unsigned int pos, void *buf,
+ size_t size)
+{
+ int i;
+
+ rtc_write(pos, DS1511_RAMADDR_LSB);
+ for (i = 0; i < size; i++)
+ rtc_write(*(char *)buf++, DS1511_RAMDATA);
+
+ return 0;
+}
+
+static int ds1511_rtc_probe(struct platform_device *pdev)
+{
+ struct ds1511_data *ds1511;
+ int ret = 0;
+ struct nvmem_config ds1511_nvmem_cfg = {
+ .name = "ds1511_nvram",
+ .word_size = 1,
+ .stride = 1,
+ .size = DS1511_RAM_MAX,
+ .reg_read = ds1511_nvram_read,
+ .reg_write = ds1511_nvram_write,
+ .priv = &pdev->dev,
+ };
+
+ ds1511 = devm_kzalloc(&pdev->dev, sizeof(*ds1511), GFP_KERNEL);
+ if (!ds1511)
+ return -ENOMEM;
+
+ ds1511_base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(ds1511_base))
+ return PTR_ERR(ds1511_base);
+ ds1511->ioaddr = ds1511_base;
+ ds1511->irq = platform_get_irq(pdev, 0);
+
+ /*
+ * turn on the clock and the crystal, etc.
+ */
+ rtc_write(DS1511_BME, DS1511_CONTROL_B);
+ rtc_write(0, DS1511_CONTROL_A);
+ /*
+ * clear the wdog counter
+ */
+ rtc_write(0, DS1511_WD_MSEC);
+ rtc_write(0, DS1511_WD_SEC);
+ /*
+ * start the clock
+ */
+ rtc_enable_update();
+
+ /*
+ * check for a dying bat-tree
+ */
+ if (rtc_read(DS1511_CONTROL_A) & DS1511_BLF1)
+ dev_warn(&pdev->dev, "voltage-low detected.\n");
+
+ spin_lock_init(&ds1511->lock);
+ platform_set_drvdata(pdev, ds1511);
+
+ ds1511->rtc = devm_rtc_allocate_device(&pdev->dev);
+ if (IS_ERR(ds1511->rtc))
+ return PTR_ERR(ds1511->rtc);
+
+ ds1511->rtc->ops = &ds1511_rtc_ops;
+ ds1511->rtc->range_max = RTC_TIMESTAMP_END_2099;
+ ds1511->rtc->alarm_offset_max = 28 * 24 * 60 * 60 - 1;
+
+ /*
+ * if the platform has an interrupt in mind for this device,
+ * then by all means, set it
+ */
+ if (ds1511->irq > 0) {
+ rtc_read(DS1511_CONTROL_A);
+ if (devm_request_irq(&pdev->dev, ds1511->irq, ds1511_interrupt,
+ IRQF_SHARED, pdev->name, pdev) < 0) {
+
+ dev_warn(&pdev->dev, "interrupt not available.\n");
+ ds1511->irq = 0;
+ }
+ }
+
+ if (ds1511->irq == 0)
+ clear_bit(RTC_FEATURE_ALARM, ds1511->rtc->features);
+
+ ret = devm_rtc_register_device(ds1511->rtc);
+ if (ret)
+ return ret;
+
+ devm_rtc_nvmem_register(ds1511->rtc, &ds1511_nvmem_cfg);
+
+ return 0;
+}
+
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:ds1511");
+
+static struct platform_driver ds1511_rtc_driver = {
+ .probe = ds1511_rtc_probe,
+ .driver = {
+ .name = "ds1511",
+ },
+};
+
+module_platform_driver(ds1511_rtc_driver);
+
+MODULE_AUTHOR("Andrew Sharp <andy.sharp@lsi.com>");
+MODULE_DESCRIPTION("Dallas DS1511 RTC driver");
+MODULE_LICENSE("GPL");