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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-max8997.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-max8997.c')
-rw-r--r--drivers/rtc/rtc-max8997.c533
1 files changed, 533 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-max8997.c b/drivers/rtc/rtc-max8997.c
new file mode 100644
index 000000000..89203c92e
--- /dev/null
+++ b/drivers/rtc/rtc-max8997.c
@@ -0,0 +1,533 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// RTC driver for Maxim MAX8997
+//
+// Copyright (C) 2013 Samsung Electronics Co.Ltd
+//
+// based on rtc-max8998.c
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/slab.h>
+#include <linux/rtc.h>
+#include <linux/delay.h>
+#include <linux/mutex.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/max8997-private.h>
+#include <linux/irqdomain.h>
+
+/* Module parameter for WTSR function control */
+static int wtsr_en = 1;
+module_param(wtsr_en, int, 0444);
+MODULE_PARM_DESC(wtsr_en, "Watchdog Timeout & Software Reset (default=on)");
+/* Module parameter for SMPL function control */
+static int smpl_en = 1;
+module_param(smpl_en, int, 0444);
+MODULE_PARM_DESC(smpl_en, "Sudden Momentary Power Loss (default=on)");
+
+/* RTC Control Register */
+#define BCD_EN_SHIFT 0
+#define BCD_EN_MASK (1 << BCD_EN_SHIFT)
+#define MODEL24_SHIFT 1
+#define MODEL24_MASK (1 << MODEL24_SHIFT)
+/* RTC Update Register1 */
+#define RTC_UDR_SHIFT 0
+#define RTC_UDR_MASK (1 << RTC_UDR_SHIFT)
+/* WTSR and SMPL Register */
+#define WTSRT_SHIFT 0
+#define SMPLT_SHIFT 2
+#define WTSR_EN_SHIFT 6
+#define SMPL_EN_SHIFT 7
+#define WTSRT_MASK (3 << WTSRT_SHIFT)
+#define SMPLT_MASK (3 << SMPLT_SHIFT)
+#define WTSR_EN_MASK (1 << WTSR_EN_SHIFT)
+#define SMPL_EN_MASK (1 << SMPL_EN_SHIFT)
+/* RTC Hour register */
+#define HOUR_PM_SHIFT 6
+#define HOUR_PM_MASK (1 << HOUR_PM_SHIFT)
+/* RTC Alarm Enable */
+#define ALARM_ENABLE_SHIFT 7
+#define ALARM_ENABLE_MASK (1 << ALARM_ENABLE_SHIFT)
+
+enum {
+ RTC_SEC = 0,
+ RTC_MIN,
+ RTC_HOUR,
+ RTC_WEEKDAY,
+ RTC_MONTH,
+ RTC_YEAR,
+ RTC_DATE,
+ RTC_NR_TIME
+};
+
+struct max8997_rtc_info {
+ struct device *dev;
+ struct max8997_dev *max8997;
+ struct i2c_client *rtc;
+ struct rtc_device *rtc_dev;
+ struct mutex lock;
+ int virq;
+ int rtc_24hr_mode;
+};
+
+static void max8997_rtc_data_to_tm(u8 *data, struct rtc_time *tm,
+ int rtc_24hr_mode)
+{
+ tm->tm_sec = data[RTC_SEC] & 0x7f;
+ tm->tm_min = data[RTC_MIN] & 0x7f;
+ if (rtc_24hr_mode)
+ tm->tm_hour = data[RTC_HOUR] & 0x1f;
+ else {
+ tm->tm_hour = data[RTC_HOUR] & 0x0f;
+ if (data[RTC_HOUR] & HOUR_PM_MASK)
+ tm->tm_hour += 12;
+ }
+
+ tm->tm_wday = fls(data[RTC_WEEKDAY] & 0x7f) - 1;
+ tm->tm_mday = data[RTC_DATE] & 0x1f;
+ tm->tm_mon = (data[RTC_MONTH] & 0x0f) - 1;
+ tm->tm_year = (data[RTC_YEAR] & 0x7f) + 100;
+ tm->tm_yday = 0;
+ tm->tm_isdst = 0;
+}
+
+static int max8997_rtc_tm_to_data(struct rtc_time *tm, u8 *data)
+{
+ data[RTC_SEC] = tm->tm_sec;
+ data[RTC_MIN] = tm->tm_min;
+ data[RTC_HOUR] = tm->tm_hour;
+ data[RTC_WEEKDAY] = 1 << tm->tm_wday;
+ data[RTC_DATE] = tm->tm_mday;
+ data[RTC_MONTH] = tm->tm_mon + 1;
+ data[RTC_YEAR] = tm->tm_year > 100 ? (tm->tm_year - 100) : 0;
+
+ if (tm->tm_year < 100) {
+ pr_warn("RTC cannot handle the year %d. Assume it's 2000.\n",
+ 1900 + tm->tm_year);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static inline int max8997_rtc_set_update_reg(struct max8997_rtc_info *info)
+{
+ int ret;
+
+ ret = max8997_write_reg(info->rtc, MAX8997_RTC_UPDATE1,
+ RTC_UDR_MASK);
+ if (ret < 0)
+ dev_err(info->dev, "%s: fail to write update reg(%d)\n",
+ __func__, ret);
+ else {
+ /* Minimum 16ms delay required before RTC update.
+ * Otherwise, we may read and update based on out-of-date
+ * value */
+ msleep(20);
+ }
+
+ return ret;
+}
+
+static int max8997_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct max8997_rtc_info *info = dev_get_drvdata(dev);
+ u8 data[RTC_NR_TIME];
+ int ret;
+
+ mutex_lock(&info->lock);
+ ret = max8997_bulk_read(info->rtc, MAX8997_RTC_SEC, RTC_NR_TIME, data);
+ mutex_unlock(&info->lock);
+
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to read time reg(%d)\n", __func__,
+ ret);
+ return ret;
+ }
+
+ max8997_rtc_data_to_tm(data, tm, info->rtc_24hr_mode);
+
+ return 0;
+}
+
+static int max8997_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct max8997_rtc_info *info = dev_get_drvdata(dev);
+ u8 data[RTC_NR_TIME];
+ int ret;
+
+ ret = max8997_rtc_tm_to_data(tm, data);
+ if (ret < 0)
+ return ret;
+
+ mutex_lock(&info->lock);
+
+ ret = max8997_bulk_write(info->rtc, MAX8997_RTC_SEC, RTC_NR_TIME, data);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to write time reg(%d)\n", __func__,
+ ret);
+ goto out;
+ }
+
+ ret = max8997_rtc_set_update_reg(info);
+out:
+ mutex_unlock(&info->lock);
+ return ret;
+}
+
+static int max8997_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct max8997_rtc_info *info = dev_get_drvdata(dev);
+ u8 data[RTC_NR_TIME];
+ u8 val;
+ int i, ret;
+
+ mutex_lock(&info->lock);
+
+ ret = max8997_bulk_read(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME,
+ data);
+ if (ret < 0) {
+ dev_err(info->dev, "%s:%d fail to read alarm reg(%d)\n",
+ __func__, __LINE__, ret);
+ goto out;
+ }
+
+ max8997_rtc_data_to_tm(data, &alrm->time, info->rtc_24hr_mode);
+
+ alrm->enabled = 0;
+ for (i = 0; i < RTC_NR_TIME; i++) {
+ if (data[i] & ALARM_ENABLE_MASK) {
+ alrm->enabled = 1;
+ break;
+ }
+ }
+
+ alrm->pending = 0;
+ ret = max8997_read_reg(info->max8997->i2c, MAX8997_REG_STATUS1, &val);
+ if (ret < 0) {
+ dev_err(info->dev, "%s:%d fail to read status1 reg(%d)\n",
+ __func__, __LINE__, ret);
+ goto out;
+ }
+
+ if (val & (1 << 4)) /* RTCA1 */
+ alrm->pending = 1;
+
+out:
+ mutex_unlock(&info->lock);
+ return ret;
+}
+
+static int max8997_rtc_stop_alarm(struct max8997_rtc_info *info)
+{
+ u8 data[RTC_NR_TIME];
+ int ret, i;
+
+ if (!mutex_is_locked(&info->lock))
+ dev_warn(info->dev, "%s: should have mutex locked\n", __func__);
+
+ ret = max8997_bulk_read(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME,
+ data);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to read alarm reg(%d)\n",
+ __func__, ret);
+ goto out;
+ }
+
+ for (i = 0; i < RTC_NR_TIME; i++)
+ data[i] &= ~ALARM_ENABLE_MASK;
+
+ ret = max8997_bulk_write(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME,
+ data);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
+ __func__, ret);
+ goto out;
+ }
+
+ ret = max8997_rtc_set_update_reg(info);
+out:
+ return ret;
+}
+
+static int max8997_rtc_start_alarm(struct max8997_rtc_info *info)
+{
+ u8 data[RTC_NR_TIME];
+ int ret;
+
+ if (!mutex_is_locked(&info->lock))
+ dev_warn(info->dev, "%s: should have mutex locked\n", __func__);
+
+ ret = max8997_bulk_read(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME,
+ data);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to read alarm reg(%d)\n",
+ __func__, ret);
+ goto out;
+ }
+
+ data[RTC_SEC] |= (1 << ALARM_ENABLE_SHIFT);
+ data[RTC_MIN] |= (1 << ALARM_ENABLE_SHIFT);
+ data[RTC_HOUR] |= (1 << ALARM_ENABLE_SHIFT);
+ data[RTC_WEEKDAY] &= ~ALARM_ENABLE_MASK;
+ if (data[RTC_MONTH] & 0xf)
+ data[RTC_MONTH] |= (1 << ALARM_ENABLE_SHIFT);
+ if (data[RTC_YEAR] & 0x7f)
+ data[RTC_YEAR] |= (1 << ALARM_ENABLE_SHIFT);
+ if (data[RTC_DATE] & 0x1f)
+ data[RTC_DATE] |= (1 << ALARM_ENABLE_SHIFT);
+
+ ret = max8997_bulk_write(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME,
+ data);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
+ __func__, ret);
+ goto out;
+ }
+
+ ret = max8997_rtc_set_update_reg(info);
+out:
+ return ret;
+}
+static int max8997_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct max8997_rtc_info *info = dev_get_drvdata(dev);
+ u8 data[RTC_NR_TIME];
+ int ret;
+
+ ret = max8997_rtc_tm_to_data(&alrm->time, data);
+ if (ret < 0)
+ return ret;
+
+ dev_info(info->dev, "%s: %d-%02d-%02d %02d:%02d:%02d\n", __func__,
+ data[RTC_YEAR] + 2000, data[RTC_MONTH], data[RTC_DATE],
+ data[RTC_HOUR], data[RTC_MIN], data[RTC_SEC]);
+
+ mutex_lock(&info->lock);
+
+ ret = max8997_rtc_stop_alarm(info);
+ if (ret < 0)
+ goto out;
+
+ ret = max8997_bulk_write(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME,
+ data);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
+ __func__, ret);
+ goto out;
+ }
+
+ ret = max8997_rtc_set_update_reg(info);
+ if (ret < 0)
+ goto out;
+
+ if (alrm->enabled)
+ ret = max8997_rtc_start_alarm(info);
+out:
+ mutex_unlock(&info->lock);
+ return ret;
+}
+
+static int max8997_rtc_alarm_irq_enable(struct device *dev,
+ unsigned int enabled)
+{
+ struct max8997_rtc_info *info = dev_get_drvdata(dev);
+ int ret;
+
+ mutex_lock(&info->lock);
+ if (enabled)
+ ret = max8997_rtc_start_alarm(info);
+ else
+ ret = max8997_rtc_stop_alarm(info);
+ mutex_unlock(&info->lock);
+
+ return ret;
+}
+
+static irqreturn_t max8997_rtc_alarm_irq(int irq, void *data)
+{
+ struct max8997_rtc_info *info = data;
+
+ dev_info(info->dev, "%s:irq(%d)\n", __func__, irq);
+
+ rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);
+
+ return IRQ_HANDLED;
+}
+
+static const struct rtc_class_ops max8997_rtc_ops = {
+ .read_time = max8997_rtc_read_time,
+ .set_time = max8997_rtc_set_time,
+ .read_alarm = max8997_rtc_read_alarm,
+ .set_alarm = max8997_rtc_set_alarm,
+ .alarm_irq_enable = max8997_rtc_alarm_irq_enable,
+};
+
+static void max8997_rtc_enable_wtsr(struct max8997_rtc_info *info, bool enable)
+{
+ int ret;
+ u8 val, mask;
+
+ if (!wtsr_en)
+ return;
+
+ if (enable)
+ val = (1 << WTSR_EN_SHIFT) | (3 << WTSRT_SHIFT);
+ else
+ val = 0;
+
+ mask = WTSR_EN_MASK | WTSRT_MASK;
+
+ dev_info(info->dev, "%s: %s WTSR\n", __func__,
+ enable ? "enable" : "disable");
+
+ ret = max8997_update_reg(info->rtc, MAX8997_RTC_WTSR_SMPL, val, mask);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to update WTSR reg(%d)\n",
+ __func__, ret);
+ return;
+ }
+
+ max8997_rtc_set_update_reg(info);
+}
+
+static void max8997_rtc_enable_smpl(struct max8997_rtc_info *info, bool enable)
+{
+ int ret;
+ u8 val, mask;
+
+ if (!smpl_en)
+ return;
+
+ if (enable)
+ val = (1 << SMPL_EN_SHIFT) | (0 << SMPLT_SHIFT);
+ else
+ val = 0;
+
+ mask = SMPL_EN_MASK | SMPLT_MASK;
+
+ dev_info(info->dev, "%s: %s SMPL\n", __func__,
+ enable ? "enable" : "disable");
+
+ ret = max8997_update_reg(info->rtc, MAX8997_RTC_WTSR_SMPL, val, mask);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to update SMPL reg(%d)\n",
+ __func__, ret);
+ return;
+ }
+
+ max8997_rtc_set_update_reg(info);
+
+ val = 0;
+ max8997_read_reg(info->rtc, MAX8997_RTC_WTSR_SMPL, &val);
+ pr_info("WTSR_SMPL(0x%02x)\n", val);
+}
+
+static int max8997_rtc_init_reg(struct max8997_rtc_info *info)
+{
+ u8 data[2];
+ int ret;
+
+ /* Set RTC control register : Binary mode, 24hour mdoe */
+ data[0] = (1 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT);
+ data[1] = (0 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT);
+
+ info->rtc_24hr_mode = 1;
+
+ ret = max8997_bulk_write(info->rtc, MAX8997_RTC_CTRLMASK, 2, data);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to write controlm reg(%d)\n",
+ __func__, ret);
+ return ret;
+ }
+
+ ret = max8997_rtc_set_update_reg(info);
+ return ret;
+}
+
+static int max8997_rtc_probe(struct platform_device *pdev)
+{
+ struct max8997_dev *max8997 = dev_get_drvdata(pdev->dev.parent);
+ struct max8997_rtc_info *info;
+ int ret, virq;
+
+ info = devm_kzalloc(&pdev->dev, sizeof(struct max8997_rtc_info),
+ GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+
+ mutex_init(&info->lock);
+ info->dev = &pdev->dev;
+ info->max8997 = max8997;
+ info->rtc = max8997->rtc;
+
+ platform_set_drvdata(pdev, info);
+
+ ret = max8997_rtc_init_reg(info);
+
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to initialize RTC reg:%d\n", ret);
+ return ret;
+ }
+
+ max8997_rtc_enable_wtsr(info, true);
+ max8997_rtc_enable_smpl(info, true);
+
+ device_init_wakeup(&pdev->dev, true);
+
+ info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8997-rtc",
+ &max8997_rtc_ops, THIS_MODULE);
+
+ if (IS_ERR(info->rtc_dev)) {
+ ret = PTR_ERR(info->rtc_dev);
+ dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
+ return ret;
+ }
+
+ virq = irq_create_mapping(max8997->irq_domain, MAX8997_PMICIRQ_RTCA1);
+ if (!virq) {
+ dev_err(&pdev->dev, "Failed to create mapping alarm IRQ\n");
+ ret = -ENXIO;
+ goto err_out;
+ }
+ info->virq = virq;
+
+ ret = devm_request_threaded_irq(&pdev->dev, virq, NULL,
+ max8997_rtc_alarm_irq, 0,
+ "rtc-alarm0", info);
+ if (ret < 0)
+ dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
+ info->virq, ret);
+
+err_out:
+ return ret;
+}
+
+static void max8997_rtc_shutdown(struct platform_device *pdev)
+{
+ struct max8997_rtc_info *info = platform_get_drvdata(pdev);
+
+ max8997_rtc_enable_wtsr(info, false);
+ max8997_rtc_enable_smpl(info, false);
+}
+
+static const struct platform_device_id rtc_id[] = {
+ { .name = "max8997-rtc" },
+ { }
+};
+MODULE_DEVICE_TABLE(platform, rtc_id);
+
+static struct platform_driver max8997_rtc_driver = {
+ .driver = {
+ .name = "max8997-rtc",
+ },
+ .probe = max8997_rtc_probe,
+ .shutdown = max8997_rtc_shutdown,
+ .id_table = rtc_id,
+};
+
+module_platform_driver(max8997_rtc_driver);
+
+MODULE_DESCRIPTION("Maxim MAX8997 RTC driver");
+MODULE_AUTHOR("<ms925.kim@samsung.com>");
+MODULE_LICENSE("GPL");