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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-ds1553.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-ds1553.c')
-rw-r--r--drivers/rtc/rtc-ds1553.c331
1 files changed, 331 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-ds1553.c b/drivers/rtc/rtc-ds1553.c
new file mode 100644
index 000000000..dbff5b621
--- /dev/null
+++ b/drivers/rtc/rtc-ds1553.c
@@ -0,0 +1,331 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * An rtc driver for the Dallas DS1553
+ *
+ * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
+ */
+
+#include <linux/bcd.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/gfp.h>
+#include <linux/delay.h>
+#include <linux/jiffies.h>
+#include <linux/interrupt.h>
+#include <linux/rtc.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/module.h>
+
+#define RTC_REG_SIZE 0x2000
+#define RTC_OFFSET 0x1ff0
+
+#define RTC_FLAGS (RTC_OFFSET + 0)
+#define RTC_SECONDS_ALARM (RTC_OFFSET + 2)
+#define RTC_MINUTES_ALARM (RTC_OFFSET + 3)
+#define RTC_HOURS_ALARM (RTC_OFFSET + 4)
+#define RTC_DATE_ALARM (RTC_OFFSET + 5)
+#define RTC_INTERRUPTS (RTC_OFFSET + 6)
+#define RTC_WATCHDOG (RTC_OFFSET + 7)
+#define RTC_CONTROL (RTC_OFFSET + 8)
+#define RTC_CENTURY (RTC_OFFSET + 8)
+#define RTC_SECONDS (RTC_OFFSET + 9)
+#define RTC_MINUTES (RTC_OFFSET + 10)
+#define RTC_HOURS (RTC_OFFSET + 11)
+#define RTC_DAY (RTC_OFFSET + 12)
+#define RTC_DATE (RTC_OFFSET + 13)
+#define RTC_MONTH (RTC_OFFSET + 14)
+#define RTC_YEAR (RTC_OFFSET + 15)
+
+#define RTC_CENTURY_MASK 0x3f
+#define RTC_SECONDS_MASK 0x7f
+#define RTC_DAY_MASK 0x07
+
+/* Bits in the Control/Century register */
+#define RTC_WRITE 0x80
+#define RTC_READ 0x40
+
+/* Bits in the Seconds register */
+#define RTC_STOP 0x80
+
+/* Bits in the Flags register */
+#define RTC_FLAGS_AF 0x40
+#define RTC_FLAGS_BLF 0x10
+
+/* Bits in the Interrupts register */
+#define RTC_INTS_AE 0x80
+
+struct rtc_plat_data {
+ struct rtc_device *rtc;
+ void __iomem *ioaddr;
+ unsigned long last_jiffies;
+ int irq;
+ unsigned int irqen;
+ int alrm_sec;
+ int alrm_min;
+ int alrm_hour;
+ int alrm_mday;
+ spinlock_t lock;
+};
+
+static int ds1553_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct rtc_plat_data *pdata = dev_get_drvdata(dev);
+ void __iomem *ioaddr = pdata->ioaddr;
+ u8 century;
+
+ century = bin2bcd((tm->tm_year + 1900) / 100);
+
+ writeb(RTC_WRITE, pdata->ioaddr + RTC_CONTROL);
+
+ writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR);
+ writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH);
+ writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY);
+ writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE);
+ writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS);
+ writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES);
+ writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS);
+
+ /* RTC_CENTURY and RTC_CONTROL share same register */
+ writeb(RTC_WRITE | (century & RTC_CENTURY_MASK), ioaddr + RTC_CENTURY);
+ writeb(century & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
+ return 0;
+}
+
+static int ds1553_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct rtc_plat_data *pdata = dev_get_drvdata(dev);
+ void __iomem *ioaddr = pdata->ioaddr;
+ unsigned int year, month, day, hour, minute, second, week;
+ unsigned int century;
+
+ /* give enough time to update RTC in case of continuous read */
+ if (pdata->last_jiffies == jiffies)
+ msleep(1);
+ pdata->last_jiffies = jiffies;
+ writeb(RTC_READ, ioaddr + RTC_CONTROL);
+ second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
+ minute = readb(ioaddr + RTC_MINUTES);
+ hour = readb(ioaddr + RTC_HOURS);
+ day = readb(ioaddr + RTC_DATE);
+ week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
+ month = readb(ioaddr + RTC_MONTH);
+ year = readb(ioaddr + RTC_YEAR);
+ century = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
+ writeb(0, ioaddr + RTC_CONTROL);
+ tm->tm_sec = bcd2bin(second);
+ tm->tm_min = bcd2bin(minute);
+ tm->tm_hour = bcd2bin(hour);
+ tm->tm_mday = bcd2bin(day);
+ tm->tm_wday = bcd2bin(week);
+ tm->tm_mon = bcd2bin(month) - 1;
+ /* year is 1900 + tm->tm_year */
+ tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900;
+
+ return 0;
+}
+
+static void ds1553_rtc_update_alarm(struct rtc_plat_data *pdata)
+{
+ void __iomem *ioaddr = pdata->ioaddr;
+ unsigned long flags;
+
+ spin_lock_irqsave(&pdata->lock, flags);
+ writeb(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ?
+ 0x80 : bin2bcd(pdata->alrm_mday),
+ ioaddr + RTC_DATE_ALARM);
+ writeb(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ?
+ 0x80 : bin2bcd(pdata->alrm_hour),
+ ioaddr + RTC_HOURS_ALARM);
+ writeb(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ?
+ 0x80 : bin2bcd(pdata->alrm_min),
+ ioaddr + RTC_MINUTES_ALARM);
+ writeb(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ?
+ 0x80 : bin2bcd(pdata->alrm_sec),
+ ioaddr + RTC_SECONDS_ALARM);
+ writeb(pdata->irqen ? RTC_INTS_AE : 0, ioaddr + RTC_INTERRUPTS);
+ readb(ioaddr + RTC_FLAGS); /* clear interrupts */
+ spin_unlock_irqrestore(&pdata->lock, flags);
+}
+
+static int ds1553_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct rtc_plat_data *pdata = dev_get_drvdata(dev);
+
+ if (pdata->irq <= 0)
+ return -EINVAL;
+ pdata->alrm_mday = alrm->time.tm_mday;
+ pdata->alrm_hour = alrm->time.tm_hour;
+ pdata->alrm_min = alrm->time.tm_min;
+ pdata->alrm_sec = alrm->time.tm_sec;
+ if (alrm->enabled)
+ pdata->irqen |= RTC_AF;
+ ds1553_rtc_update_alarm(pdata);
+ return 0;
+}
+
+static int ds1553_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct rtc_plat_data *pdata = dev_get_drvdata(dev);
+
+ if (pdata->irq <= 0)
+ return -EINVAL;
+ alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
+ alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
+ alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
+ alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
+ alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
+ return 0;
+}
+
+static irqreturn_t ds1553_rtc_interrupt(int irq, void *dev_id)
+{
+ struct platform_device *pdev = dev_id;
+ struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+ void __iomem *ioaddr = pdata->ioaddr;
+ unsigned long events = 0;
+
+ spin_lock(&pdata->lock);
+ /* read and clear interrupt */
+ if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF) {
+ events = RTC_IRQF;
+ if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80)
+ events |= RTC_UF;
+ else
+ events |= RTC_AF;
+ rtc_update_irq(pdata->rtc, 1, events);
+ }
+ spin_unlock(&pdata->lock);
+ return events ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static int ds1553_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+ struct rtc_plat_data *pdata = dev_get_drvdata(dev);
+
+ if (pdata->irq <= 0)
+ return -EINVAL;
+ if (enabled)
+ pdata->irqen |= RTC_AF;
+ else
+ pdata->irqen &= ~RTC_AF;
+ ds1553_rtc_update_alarm(pdata);
+ return 0;
+}
+
+static const struct rtc_class_ops ds1553_rtc_ops = {
+ .read_time = ds1553_rtc_read_time,
+ .set_time = ds1553_rtc_set_time,
+ .read_alarm = ds1553_rtc_read_alarm,
+ .set_alarm = ds1553_rtc_set_alarm,
+ .alarm_irq_enable = ds1553_rtc_alarm_irq_enable,
+};
+
+static int ds1553_nvram_read(void *priv, unsigned int pos, void *val,
+ size_t bytes)
+{
+ struct platform_device *pdev = priv;
+ struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+ void __iomem *ioaddr = pdata->ioaddr;
+ u8 *buf = val;
+
+ for (; bytes; bytes--)
+ *buf++ = readb(ioaddr + pos++);
+ return 0;
+}
+
+static int ds1553_nvram_write(void *priv, unsigned int pos, void *val,
+ size_t bytes)
+{
+ struct platform_device *pdev = priv;
+ struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+ void __iomem *ioaddr = pdata->ioaddr;
+ u8 *buf = val;
+
+ for (; bytes; bytes--)
+ writeb(*buf++, ioaddr + pos++);
+ return 0;
+}
+
+static int ds1553_rtc_probe(struct platform_device *pdev)
+{
+ unsigned int cen, sec;
+ struct rtc_plat_data *pdata;
+ void __iomem *ioaddr;
+ int ret = 0;
+ struct nvmem_config nvmem_cfg = {
+ .name = "ds1553_nvram",
+ .word_size = 1,
+ .stride = 1,
+ .size = RTC_OFFSET,
+ .reg_read = ds1553_nvram_read,
+ .reg_write = ds1553_nvram_write,
+ .priv = pdev,
+ };
+
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata)
+ return -ENOMEM;
+
+ ioaddr = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(ioaddr))
+ return PTR_ERR(ioaddr);
+ pdata->ioaddr = ioaddr;
+ pdata->irq = platform_get_irq(pdev, 0);
+
+ /* turn RTC on if it was not on */
+ sec = readb(ioaddr + RTC_SECONDS);
+ if (sec & RTC_STOP) {
+ sec &= RTC_SECONDS_MASK;
+ cen = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
+ writeb(RTC_WRITE, ioaddr + RTC_CONTROL);
+ writeb(sec, ioaddr + RTC_SECONDS);
+ writeb(cen & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
+ }
+ if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_BLF)
+ dev_warn(&pdev->dev, "voltage-low detected.\n");
+
+ spin_lock_init(&pdata->lock);
+ pdata->last_jiffies = jiffies;
+ platform_set_drvdata(pdev, pdata);
+
+ pdata->rtc = devm_rtc_allocate_device(&pdev->dev);
+ if (IS_ERR(pdata->rtc))
+ return PTR_ERR(pdata->rtc);
+
+ pdata->rtc->ops = &ds1553_rtc_ops;
+
+ ret = devm_rtc_register_device(pdata->rtc);
+ if (ret)
+ return ret;
+
+ if (pdata->irq > 0) {
+ writeb(0, ioaddr + RTC_INTERRUPTS);
+ if (devm_request_irq(&pdev->dev, pdata->irq,
+ ds1553_rtc_interrupt,
+ 0, pdev->name, pdev) < 0) {
+ dev_warn(&pdev->dev, "interrupt not available.\n");
+ pdata->irq = 0;
+ }
+ }
+
+ devm_rtc_nvmem_register(pdata->rtc, &nvmem_cfg);
+
+ return 0;
+}
+
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:rtc-ds1553");
+
+static struct platform_driver ds1553_rtc_driver = {
+ .probe = ds1553_rtc_probe,
+ .driver = {
+ .name = "rtc-ds1553",
+ },
+};
+
+module_platform_driver(ds1553_rtc_driver);
+
+MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
+MODULE_DESCRIPTION("Dallas DS1553 RTC driver");
+MODULE_LICENSE("GPL");