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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-vt8500.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-vt8500.c')
-rw-r--r--drivers/rtc/rtc-vt8500.c266
1 files changed, 266 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-vt8500.c b/drivers/rtc/rtc-vt8500.c
new file mode 100644
index 000000000..c8b568498
--- /dev/null
+++ b/drivers/rtc/rtc-vt8500.c
@@ -0,0 +1,266 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * drivers/rtc/rtc-vt8500.c
+ *
+ * Copyright (C) 2010 Alexey Charkov <alchark@gmail.com>
+ *
+ * Based on rtc-pxa.c
+ */
+
+#include <linux/module.h>
+#include <linux/rtc.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/bcd.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+
+/*
+ * Register definitions
+ */
+#define VT8500_RTC_TS 0x00 /* Time set */
+#define VT8500_RTC_DS 0x04 /* Date set */
+#define VT8500_RTC_AS 0x08 /* Alarm set */
+#define VT8500_RTC_CR 0x0c /* Control */
+#define VT8500_RTC_TR 0x10 /* Time read */
+#define VT8500_RTC_DR 0x14 /* Date read */
+#define VT8500_RTC_WS 0x18 /* Write status */
+#define VT8500_RTC_CL 0x20 /* Calibration */
+#define VT8500_RTC_IS 0x24 /* Interrupt status */
+#define VT8500_RTC_ST 0x28 /* Status */
+
+#define INVALID_TIME_BIT (1 << 31)
+
+#define DATE_CENTURY_S 19
+#define DATE_YEAR_S 11
+#define DATE_YEAR_MASK (0xff << DATE_YEAR_S)
+#define DATE_MONTH_S 6
+#define DATE_MONTH_MASK (0x1f << DATE_MONTH_S)
+#define DATE_DAY_MASK 0x3f
+
+#define TIME_DOW_S 20
+#define TIME_DOW_MASK (0x07 << TIME_DOW_S)
+#define TIME_HOUR_S 14
+#define TIME_HOUR_MASK (0x3f << TIME_HOUR_S)
+#define TIME_MIN_S 7
+#define TIME_MIN_MASK (0x7f << TIME_MIN_S)
+#define TIME_SEC_MASK 0x7f
+
+#define ALARM_DAY_S 20
+#define ALARM_DAY_MASK (0x3f << ALARM_DAY_S)
+
+#define ALARM_DAY_BIT (1 << 29)
+#define ALARM_HOUR_BIT (1 << 28)
+#define ALARM_MIN_BIT (1 << 27)
+#define ALARM_SEC_BIT (1 << 26)
+
+#define ALARM_ENABLE_MASK (ALARM_DAY_BIT \
+ | ALARM_HOUR_BIT \
+ | ALARM_MIN_BIT \
+ | ALARM_SEC_BIT)
+
+#define VT8500_RTC_CR_ENABLE (1 << 0) /* Enable RTC */
+#define VT8500_RTC_CR_12H (1 << 1) /* 12h time format */
+#define VT8500_RTC_CR_SM_ENABLE (1 << 2) /* Enable periodic irqs */
+#define VT8500_RTC_CR_SM_SEC (1 << 3) /* 0: 1Hz/60, 1: 1Hz */
+#define VT8500_RTC_CR_CALIB (1 << 4) /* Enable calibration */
+
+#define VT8500_RTC_IS_ALARM (1 << 0) /* Alarm interrupt status */
+
+struct vt8500_rtc {
+ void __iomem *regbase;
+ int irq_alarm;
+ struct rtc_device *rtc;
+ spinlock_t lock; /* Protects this structure */
+};
+
+static irqreturn_t vt8500_rtc_irq(int irq, void *dev_id)
+{
+ struct vt8500_rtc *vt8500_rtc = dev_id;
+ u32 isr;
+ unsigned long events = 0;
+
+ spin_lock(&vt8500_rtc->lock);
+
+ /* clear interrupt sources */
+ isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS);
+ writel(isr, vt8500_rtc->regbase + VT8500_RTC_IS);
+
+ spin_unlock(&vt8500_rtc->lock);
+
+ if (isr & VT8500_RTC_IS_ALARM)
+ events |= RTC_AF | RTC_IRQF;
+
+ rtc_update_irq(vt8500_rtc->rtc, 1, events);
+
+ return IRQ_HANDLED;
+}
+
+static int vt8500_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
+ u32 date, time;
+
+ date = readl(vt8500_rtc->regbase + VT8500_RTC_DR);
+ time = readl(vt8500_rtc->regbase + VT8500_RTC_TR);
+
+ tm->tm_sec = bcd2bin(time & TIME_SEC_MASK);
+ tm->tm_min = bcd2bin((time & TIME_MIN_MASK) >> TIME_MIN_S);
+ tm->tm_hour = bcd2bin((time & TIME_HOUR_MASK) >> TIME_HOUR_S);
+ tm->tm_mday = bcd2bin(date & DATE_DAY_MASK);
+ tm->tm_mon = bcd2bin((date & DATE_MONTH_MASK) >> DATE_MONTH_S) - 1;
+ tm->tm_year = bcd2bin((date & DATE_YEAR_MASK) >> DATE_YEAR_S)
+ + ((date >> DATE_CENTURY_S) & 1 ? 200 : 100);
+ tm->tm_wday = (time & TIME_DOW_MASK) >> TIME_DOW_S;
+
+ return 0;
+}
+
+static int vt8500_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
+
+ writel((bin2bcd(tm->tm_year % 100) << DATE_YEAR_S)
+ | (bin2bcd(tm->tm_mon + 1) << DATE_MONTH_S)
+ | (bin2bcd(tm->tm_mday))
+ | ((tm->tm_year >= 200) << DATE_CENTURY_S),
+ vt8500_rtc->regbase + VT8500_RTC_DS);
+ writel((bin2bcd(tm->tm_wday) << TIME_DOW_S)
+ | (bin2bcd(tm->tm_hour) << TIME_HOUR_S)
+ | (bin2bcd(tm->tm_min) << TIME_MIN_S)
+ | (bin2bcd(tm->tm_sec)),
+ vt8500_rtc->regbase + VT8500_RTC_TS);
+
+ return 0;
+}
+
+static int vt8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
+ u32 isr, alarm;
+
+ alarm = readl(vt8500_rtc->regbase + VT8500_RTC_AS);
+ isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS);
+
+ alrm->time.tm_mday = bcd2bin((alarm & ALARM_DAY_MASK) >> ALARM_DAY_S);
+ alrm->time.tm_hour = bcd2bin((alarm & TIME_HOUR_MASK) >> TIME_HOUR_S);
+ alrm->time.tm_min = bcd2bin((alarm & TIME_MIN_MASK) >> TIME_MIN_S);
+ alrm->time.tm_sec = bcd2bin((alarm & TIME_SEC_MASK));
+
+ alrm->enabled = (alarm & ALARM_ENABLE_MASK) ? 1 : 0;
+ alrm->pending = (isr & VT8500_RTC_IS_ALARM) ? 1 : 0;
+
+ return rtc_valid_tm(&alrm->time);
+}
+
+static int vt8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
+
+ writel((alrm->enabled ? ALARM_ENABLE_MASK : 0)
+ | (bin2bcd(alrm->time.tm_mday) << ALARM_DAY_S)
+ | (bin2bcd(alrm->time.tm_hour) << TIME_HOUR_S)
+ | (bin2bcd(alrm->time.tm_min) << TIME_MIN_S)
+ | (bin2bcd(alrm->time.tm_sec)),
+ vt8500_rtc->regbase + VT8500_RTC_AS);
+
+ return 0;
+}
+
+static int vt8500_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+ struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
+ unsigned long tmp = readl(vt8500_rtc->regbase + VT8500_RTC_AS);
+
+ if (enabled)
+ tmp |= ALARM_ENABLE_MASK;
+ else
+ tmp &= ~ALARM_ENABLE_MASK;
+
+ writel(tmp, vt8500_rtc->regbase + VT8500_RTC_AS);
+ return 0;
+}
+
+static const struct rtc_class_ops vt8500_rtc_ops = {
+ .read_time = vt8500_rtc_read_time,
+ .set_time = vt8500_rtc_set_time,
+ .read_alarm = vt8500_rtc_read_alarm,
+ .set_alarm = vt8500_rtc_set_alarm,
+ .alarm_irq_enable = vt8500_alarm_irq_enable,
+};
+
+static int vt8500_rtc_probe(struct platform_device *pdev)
+{
+ struct vt8500_rtc *vt8500_rtc;
+ int ret;
+
+ vt8500_rtc = devm_kzalloc(&pdev->dev,
+ sizeof(struct vt8500_rtc), GFP_KERNEL);
+ if (!vt8500_rtc)
+ return -ENOMEM;
+
+ spin_lock_init(&vt8500_rtc->lock);
+ platform_set_drvdata(pdev, vt8500_rtc);
+
+ vt8500_rtc->irq_alarm = platform_get_irq(pdev, 0);
+ if (vt8500_rtc->irq_alarm < 0)
+ return vt8500_rtc->irq_alarm;
+
+ vt8500_rtc->regbase = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(vt8500_rtc->regbase))
+ return PTR_ERR(vt8500_rtc->regbase);
+
+ /* Enable RTC and set it to 24-hour mode */
+ writel(VT8500_RTC_CR_ENABLE,
+ vt8500_rtc->regbase + VT8500_RTC_CR);
+
+ vt8500_rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
+ if (IS_ERR(vt8500_rtc->rtc))
+ return PTR_ERR(vt8500_rtc->rtc);
+
+ vt8500_rtc->rtc->ops = &vt8500_rtc_ops;
+ vt8500_rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+ vt8500_rtc->rtc->range_max = RTC_TIMESTAMP_END_2199;
+
+ ret = devm_request_irq(&pdev->dev, vt8500_rtc->irq_alarm,
+ vt8500_rtc_irq, 0, "rtc alarm", vt8500_rtc);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "can't get irq %i, err %d\n",
+ vt8500_rtc->irq_alarm, ret);
+ return ret;
+ }
+
+ return devm_rtc_register_device(vt8500_rtc->rtc);
+}
+
+static void vt8500_rtc_remove(struct platform_device *pdev)
+{
+ struct vt8500_rtc *vt8500_rtc = platform_get_drvdata(pdev);
+
+ /* Disable alarm matching */
+ writel(0, vt8500_rtc->regbase + VT8500_RTC_IS);
+}
+
+static const struct of_device_id wmt_dt_ids[] = {
+ { .compatible = "via,vt8500-rtc", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, wmt_dt_ids);
+
+static struct platform_driver vt8500_rtc_driver = {
+ .probe = vt8500_rtc_probe,
+ .remove = vt8500_rtc_remove,
+ .driver = {
+ .name = "vt8500-rtc",
+ .of_match_table = wmt_dt_ids,
+ },
+};
+
+module_platform_driver(vt8500_rtc_driver);
+
+MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
+MODULE_DESCRIPTION("VIA VT8500 SoC Realtime Clock Driver (RTC)");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:vt8500-rtc");