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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-r7301.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-r7301.c')
-rw-r--r--drivers/rtc/rtc-r7301.c479
1 files changed, 479 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-r7301.c b/drivers/rtc/rtc-r7301.c
new file mode 100644
index 000000000..6323b7771
--- /dev/null
+++ b/drivers/rtc/rtc-r7301.c
@@ -0,0 +1,479 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * EPSON TOYOCOM RTC-7301SF/DG Driver
+ *
+ * Copyright (c) 2016 Akinobu Mita <akinobu.mita@gmail.com>
+ *
+ * Based on rtc-rp5c01.c
+ *
+ * Datasheet: http://www5.epsondevice.com/en/products/parallel/rtc7301sf.html
+ */
+
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+
+#define DRV_NAME "rtc-r7301"
+
+#define RTC7301_1_SEC 0x0 /* Bank 0 and Band 1 */
+#define RTC7301_10_SEC 0x1 /* Bank 0 and Band 1 */
+#define RTC7301_AE BIT(3)
+#define RTC7301_1_MIN 0x2 /* Bank 0 and Band 1 */
+#define RTC7301_10_MIN 0x3 /* Bank 0 and Band 1 */
+#define RTC7301_1_HOUR 0x4 /* Bank 0 and Band 1 */
+#define RTC7301_10_HOUR 0x5 /* Bank 0 and Band 1 */
+#define RTC7301_DAY_OF_WEEK 0x6 /* Bank 0 and Band 1 */
+#define RTC7301_1_DAY 0x7 /* Bank 0 and Band 1 */
+#define RTC7301_10_DAY 0x8 /* Bank 0 and Band 1 */
+#define RTC7301_1_MONTH 0x9 /* Bank 0 */
+#define RTC7301_10_MONTH 0xa /* Bank 0 */
+#define RTC7301_1_YEAR 0xb /* Bank 0 */
+#define RTC7301_10_YEAR 0xc /* Bank 0 */
+#define RTC7301_100_YEAR 0xd /* Bank 0 */
+#define RTC7301_1000_YEAR 0xe /* Bank 0 */
+#define RTC7301_ALARM_CONTROL 0xe /* Bank 1 */
+#define RTC7301_ALARM_CONTROL_AIE BIT(0)
+#define RTC7301_ALARM_CONTROL_AF BIT(1)
+#define RTC7301_TIMER_CONTROL 0xe /* Bank 2 */
+#define RTC7301_TIMER_CONTROL_TIE BIT(0)
+#define RTC7301_TIMER_CONTROL_TF BIT(1)
+#define RTC7301_CONTROL 0xf /* All banks */
+#define RTC7301_CONTROL_BUSY BIT(0)
+#define RTC7301_CONTROL_STOP BIT(1)
+#define RTC7301_CONTROL_BANK_SEL_0 BIT(2)
+#define RTC7301_CONTROL_BANK_SEL_1 BIT(3)
+
+struct rtc7301_priv {
+ struct regmap *regmap;
+ int irq;
+ spinlock_t lock;
+ u8 bank;
+};
+
+/*
+ * When the device is memory-mapped, some platforms pack the registers into
+ * 32-bit access using the lower 8 bits at each 4-byte stride, while others
+ * expose them as simply consecutive bytes.
+ */
+static const struct regmap_config rtc7301_regmap_32_config = {
+ .reg_bits = 32,
+ .val_bits = 8,
+ .reg_stride = 4,
+};
+
+static const struct regmap_config rtc7301_regmap_8_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .reg_stride = 1,
+};
+
+static u8 rtc7301_read(struct rtc7301_priv *priv, unsigned int reg)
+{
+ int reg_stride = regmap_get_reg_stride(priv->regmap);
+ unsigned int val;
+
+ regmap_read(priv->regmap, reg_stride * reg, &val);
+
+ return val & 0xf;
+}
+
+static void rtc7301_write(struct rtc7301_priv *priv, u8 val, unsigned int reg)
+{
+ int reg_stride = regmap_get_reg_stride(priv->regmap);
+
+ regmap_write(priv->regmap, reg_stride * reg, val);
+}
+
+static void rtc7301_update_bits(struct rtc7301_priv *priv, unsigned int reg,
+ u8 mask, u8 val)
+{
+ int reg_stride = regmap_get_reg_stride(priv->regmap);
+
+ regmap_update_bits(priv->regmap, reg_stride * reg, mask, val);
+}
+
+static int rtc7301_wait_while_busy(struct rtc7301_priv *priv)
+{
+ int retries = 100;
+
+ while (retries-- > 0) {
+ u8 val;
+
+ val = rtc7301_read(priv, RTC7301_CONTROL);
+ if (!(val & RTC7301_CONTROL_BUSY))
+ return 0;
+
+ udelay(300);
+ }
+
+ return -ETIMEDOUT;
+}
+
+static void rtc7301_stop(struct rtc7301_priv *priv)
+{
+ rtc7301_update_bits(priv, RTC7301_CONTROL, RTC7301_CONTROL_STOP,
+ RTC7301_CONTROL_STOP);
+}
+
+static void rtc7301_start(struct rtc7301_priv *priv)
+{
+ rtc7301_update_bits(priv, RTC7301_CONTROL, RTC7301_CONTROL_STOP, 0);
+}
+
+static void rtc7301_select_bank(struct rtc7301_priv *priv, u8 bank)
+{
+ u8 val = 0;
+
+ if (bank == priv->bank)
+ return;
+
+ if (bank & BIT(0))
+ val |= RTC7301_CONTROL_BANK_SEL_0;
+ if (bank & BIT(1))
+ val |= RTC7301_CONTROL_BANK_SEL_1;
+
+ rtc7301_update_bits(priv, RTC7301_CONTROL,
+ RTC7301_CONTROL_BANK_SEL_0 |
+ RTC7301_CONTROL_BANK_SEL_1, val);
+
+ priv->bank = bank;
+}
+
+static void rtc7301_get_time(struct rtc7301_priv *priv, struct rtc_time *tm,
+ bool alarm)
+{
+ int year;
+
+ tm->tm_sec = rtc7301_read(priv, RTC7301_1_SEC);
+ tm->tm_sec += (rtc7301_read(priv, RTC7301_10_SEC) & ~RTC7301_AE) * 10;
+ tm->tm_min = rtc7301_read(priv, RTC7301_1_MIN);
+ tm->tm_min += (rtc7301_read(priv, RTC7301_10_MIN) & ~RTC7301_AE) * 10;
+ tm->tm_hour = rtc7301_read(priv, RTC7301_1_HOUR);
+ tm->tm_hour += (rtc7301_read(priv, RTC7301_10_HOUR) & ~RTC7301_AE) * 10;
+ tm->tm_mday = rtc7301_read(priv, RTC7301_1_DAY);
+ tm->tm_mday += (rtc7301_read(priv, RTC7301_10_DAY) & ~RTC7301_AE) * 10;
+
+ if (alarm) {
+ tm->tm_wday = -1;
+ tm->tm_mon = -1;
+ tm->tm_year = -1;
+ tm->tm_yday = -1;
+ tm->tm_isdst = -1;
+ return;
+ }
+
+ tm->tm_wday = (rtc7301_read(priv, RTC7301_DAY_OF_WEEK) & ~RTC7301_AE);
+ tm->tm_mon = rtc7301_read(priv, RTC7301_10_MONTH) * 10 +
+ rtc7301_read(priv, RTC7301_1_MONTH) - 1;
+ year = rtc7301_read(priv, RTC7301_1000_YEAR) * 1000 +
+ rtc7301_read(priv, RTC7301_100_YEAR) * 100 +
+ rtc7301_read(priv, RTC7301_10_YEAR) * 10 +
+ rtc7301_read(priv, RTC7301_1_YEAR);
+
+ tm->tm_year = year - 1900;
+}
+
+static void rtc7301_write_time(struct rtc7301_priv *priv, struct rtc_time *tm,
+ bool alarm)
+{
+ int year;
+
+ rtc7301_write(priv, tm->tm_sec % 10, RTC7301_1_SEC);
+ rtc7301_write(priv, tm->tm_sec / 10, RTC7301_10_SEC);
+
+ rtc7301_write(priv, tm->tm_min % 10, RTC7301_1_MIN);
+ rtc7301_write(priv, tm->tm_min / 10, RTC7301_10_MIN);
+
+ rtc7301_write(priv, tm->tm_hour % 10, RTC7301_1_HOUR);
+ rtc7301_write(priv, tm->tm_hour / 10, RTC7301_10_HOUR);
+
+ rtc7301_write(priv, tm->tm_mday % 10, RTC7301_1_DAY);
+ rtc7301_write(priv, tm->tm_mday / 10, RTC7301_10_DAY);
+
+ /* Don't care for alarm register */
+ rtc7301_write(priv, alarm ? RTC7301_AE : tm->tm_wday,
+ RTC7301_DAY_OF_WEEK);
+
+ if (alarm)
+ return;
+
+ rtc7301_write(priv, (tm->tm_mon + 1) % 10, RTC7301_1_MONTH);
+ rtc7301_write(priv, (tm->tm_mon + 1) / 10, RTC7301_10_MONTH);
+
+ year = tm->tm_year + 1900;
+
+ rtc7301_write(priv, year % 10, RTC7301_1_YEAR);
+ rtc7301_write(priv, (year / 10) % 10, RTC7301_10_YEAR);
+ rtc7301_write(priv, (year / 100) % 10, RTC7301_100_YEAR);
+ rtc7301_write(priv, year / 1000, RTC7301_1000_YEAR);
+}
+
+static void rtc7301_alarm_irq(struct rtc7301_priv *priv, unsigned int enabled)
+{
+ rtc7301_update_bits(priv, RTC7301_ALARM_CONTROL,
+ RTC7301_ALARM_CONTROL_AF |
+ RTC7301_ALARM_CONTROL_AIE,
+ enabled ? RTC7301_ALARM_CONTROL_AIE : 0);
+}
+
+static int rtc7301_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct rtc7301_priv *priv = dev_get_drvdata(dev);
+ unsigned long flags;
+ int err;
+
+ spin_lock_irqsave(&priv->lock, flags);
+
+ rtc7301_select_bank(priv, 0);
+
+ err = rtc7301_wait_while_busy(priv);
+ if (!err)
+ rtc7301_get_time(priv, tm, false);
+
+ spin_unlock_irqrestore(&priv->lock, flags);
+
+ return err;
+}
+
+static int rtc7301_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct rtc7301_priv *priv = dev_get_drvdata(dev);
+ unsigned long flags;
+
+ spin_lock_irqsave(&priv->lock, flags);
+
+ rtc7301_stop(priv);
+ udelay(300);
+ rtc7301_select_bank(priv, 0);
+ rtc7301_write_time(priv, tm, false);
+ rtc7301_start(priv);
+
+ spin_unlock_irqrestore(&priv->lock, flags);
+
+ return 0;
+}
+
+static int rtc7301_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+ struct rtc7301_priv *priv = dev_get_drvdata(dev);
+ unsigned long flags;
+ u8 alrm_ctrl;
+
+ if (priv->irq <= 0)
+ return -EINVAL;
+
+ spin_lock_irqsave(&priv->lock, flags);
+
+ rtc7301_select_bank(priv, 1);
+ rtc7301_get_time(priv, &alarm->time, true);
+
+ alrm_ctrl = rtc7301_read(priv, RTC7301_ALARM_CONTROL);
+
+ alarm->enabled = !!(alrm_ctrl & RTC7301_ALARM_CONTROL_AIE);
+ alarm->pending = !!(alrm_ctrl & RTC7301_ALARM_CONTROL_AF);
+
+ spin_unlock_irqrestore(&priv->lock, flags);
+
+ return 0;
+}
+
+static int rtc7301_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+ struct rtc7301_priv *priv = dev_get_drvdata(dev);
+ unsigned long flags;
+
+ if (priv->irq <= 0)
+ return -EINVAL;
+
+ spin_lock_irqsave(&priv->lock, flags);
+
+ rtc7301_select_bank(priv, 1);
+ rtc7301_write_time(priv, &alarm->time, true);
+ rtc7301_alarm_irq(priv, alarm->enabled);
+
+ spin_unlock_irqrestore(&priv->lock, flags);
+
+ return 0;
+}
+
+static int rtc7301_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+ struct rtc7301_priv *priv = dev_get_drvdata(dev);
+ unsigned long flags;
+
+ if (priv->irq <= 0)
+ return -EINVAL;
+
+ spin_lock_irqsave(&priv->lock, flags);
+
+ rtc7301_select_bank(priv, 1);
+ rtc7301_alarm_irq(priv, enabled);
+
+ spin_unlock_irqrestore(&priv->lock, flags);
+
+ return 0;
+}
+
+static const struct rtc_class_ops rtc7301_rtc_ops = {
+ .read_time = rtc7301_read_time,
+ .set_time = rtc7301_set_time,
+ .read_alarm = rtc7301_read_alarm,
+ .set_alarm = rtc7301_set_alarm,
+ .alarm_irq_enable = rtc7301_alarm_irq_enable,
+};
+
+static irqreturn_t rtc7301_irq_handler(int irq, void *dev_id)
+{
+ struct rtc_device *rtc = dev_id;
+ struct rtc7301_priv *priv = dev_get_drvdata(rtc->dev.parent);
+ irqreturn_t ret = IRQ_NONE;
+ u8 alrm_ctrl;
+
+ spin_lock(&priv->lock);
+
+ rtc7301_select_bank(priv, 1);
+
+ alrm_ctrl = rtc7301_read(priv, RTC7301_ALARM_CONTROL);
+ if (alrm_ctrl & RTC7301_ALARM_CONTROL_AF) {
+ ret = IRQ_HANDLED;
+ rtc7301_alarm_irq(priv, false);
+ rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
+ }
+
+ spin_unlock(&priv->lock);
+
+ return ret;
+}
+
+static void rtc7301_init(struct rtc7301_priv *priv)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&priv->lock, flags);
+
+ rtc7301_select_bank(priv, 2);
+ rtc7301_write(priv, 0, RTC7301_TIMER_CONTROL);
+
+ spin_unlock_irqrestore(&priv->lock, flags);
+}
+
+static int __init rtc7301_rtc_probe(struct platform_device *dev)
+{
+ void __iomem *regs;
+ struct rtc7301_priv *priv;
+ struct rtc_device *rtc;
+ static const struct regmap_config *mapconf;
+ int ret;
+ u32 val;
+
+ priv = devm_kzalloc(&dev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ regs = devm_platform_ioremap_resource(dev, 0);
+ if (IS_ERR(regs))
+ return PTR_ERR(regs);
+
+ ret = device_property_read_u32(&dev->dev, "reg-io-width", &val);
+ if (ret)
+ /* Default to 32bit accesses */
+ val = 4;
+
+ switch (val) {
+ case 1:
+ mapconf = &rtc7301_regmap_8_config;
+ break;
+ case 4:
+ mapconf = &rtc7301_regmap_32_config;
+ break;
+ default:
+ dev_err(&dev->dev, "invalid reg-io-width %d\n", val);
+ return -EINVAL;
+ }
+
+ priv->regmap = devm_regmap_init_mmio(&dev->dev, regs,
+ mapconf);
+ if (IS_ERR(priv->regmap))
+ return PTR_ERR(priv->regmap);
+
+ priv->irq = platform_get_irq(dev, 0);
+
+ spin_lock_init(&priv->lock);
+ priv->bank = -1;
+
+ rtc7301_init(priv);
+
+ platform_set_drvdata(dev, priv);
+
+ rtc = devm_rtc_device_register(&dev->dev, DRV_NAME, &rtc7301_rtc_ops,
+ THIS_MODULE);
+ if (IS_ERR(rtc))
+ return PTR_ERR(rtc);
+
+ if (priv->irq > 0) {
+ ret = devm_request_irq(&dev->dev, priv->irq,
+ rtc7301_irq_handler, IRQF_SHARED,
+ dev_name(&dev->dev), rtc);
+ if (ret) {
+ priv->irq = 0;
+ dev_err(&dev->dev, "unable to request IRQ\n");
+ } else {
+ device_set_wakeup_capable(&dev->dev, true);
+ }
+ }
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+
+static int rtc7301_suspend(struct device *dev)
+{
+ struct rtc7301_priv *priv = dev_get_drvdata(dev);
+
+ if (device_may_wakeup(dev))
+ enable_irq_wake(priv->irq);
+
+ return 0;
+}
+
+static int rtc7301_resume(struct device *dev)
+{
+ struct rtc7301_priv *priv = dev_get_drvdata(dev);
+
+ if (device_may_wakeup(dev))
+ disable_irq_wake(priv->irq);
+
+ return 0;
+}
+
+#endif
+
+static SIMPLE_DEV_PM_OPS(rtc7301_pm_ops, rtc7301_suspend, rtc7301_resume);
+
+static const struct of_device_id rtc7301_dt_match[] = {
+ { .compatible = "epson,rtc7301sf" },
+ { .compatible = "epson,rtc7301dg" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, rtc7301_dt_match);
+
+static struct platform_driver rtc7301_rtc_driver = {
+ .driver = {
+ .name = DRV_NAME,
+ .of_match_table = rtc7301_dt_match,
+ .pm = &rtc7301_pm_ops,
+ },
+};
+
+module_platform_driver_probe(rtc7301_rtc_driver, rtc7301_rtc_probe);
+
+MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("EPSON TOYOCOM RTC-7301SF/DG Driver");
+MODULE_ALIAS("platform:rtc-r7301");