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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-mxc.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-mxc.c')
-rw-r--r--drivers/rtc/rtc-mxc.c404
1 files changed, 404 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-mxc.c b/drivers/rtc/rtc-mxc.c
new file mode 100644
index 000000000..608db97d4
--- /dev/null
+++ b/drivers/rtc/rtc-mxc.c
@@ -0,0 +1,404 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// Copyright 2004-2008 Freescale Semiconductor, Inc. All Rights Reserved.
+
+#include <linux/io.h>
+#include <linux/rtc.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/pm_wakeirq.h>
+#include <linux/clk.h>
+#include <linux/of.h>
+
+#define RTC_INPUT_CLK_32768HZ (0x00 << 5)
+#define RTC_INPUT_CLK_32000HZ (0x01 << 5)
+#define RTC_INPUT_CLK_38400HZ (0x02 << 5)
+
+#define RTC_SW_BIT (1 << 0)
+#define RTC_ALM_BIT (1 << 2)
+#define RTC_1HZ_BIT (1 << 4)
+#define RTC_2HZ_BIT (1 << 7)
+#define RTC_SAM0_BIT (1 << 8)
+#define RTC_SAM1_BIT (1 << 9)
+#define RTC_SAM2_BIT (1 << 10)
+#define RTC_SAM3_BIT (1 << 11)
+#define RTC_SAM4_BIT (1 << 12)
+#define RTC_SAM5_BIT (1 << 13)
+#define RTC_SAM6_BIT (1 << 14)
+#define RTC_SAM7_BIT (1 << 15)
+#define PIT_ALL_ON (RTC_2HZ_BIT | RTC_SAM0_BIT | RTC_SAM1_BIT | \
+ RTC_SAM2_BIT | RTC_SAM3_BIT | RTC_SAM4_BIT | \
+ RTC_SAM5_BIT | RTC_SAM6_BIT | RTC_SAM7_BIT)
+
+#define RTC_ENABLE_BIT (1 << 7)
+
+#define MAX_PIE_NUM 9
+#define MAX_PIE_FREQ 512
+
+#define MXC_RTC_TIME 0
+#define MXC_RTC_ALARM 1
+
+#define RTC_HOURMIN 0x00 /* 32bit rtc hour/min counter reg */
+#define RTC_SECOND 0x04 /* 32bit rtc seconds counter reg */
+#define RTC_ALRM_HM 0x08 /* 32bit rtc alarm hour/min reg */
+#define RTC_ALRM_SEC 0x0C /* 32bit rtc alarm seconds reg */
+#define RTC_RTCCTL 0x10 /* 32bit rtc control reg */
+#define RTC_RTCISR 0x14 /* 32bit rtc interrupt status reg */
+#define RTC_RTCIENR 0x18 /* 32bit rtc interrupt enable reg */
+#define RTC_STPWCH 0x1C /* 32bit rtc stopwatch min reg */
+#define RTC_DAYR 0x20 /* 32bit rtc days counter reg */
+#define RTC_DAYALARM 0x24 /* 32bit rtc day alarm reg */
+#define RTC_TEST1 0x28 /* 32bit rtc test reg 1 */
+#define RTC_TEST2 0x2C /* 32bit rtc test reg 2 */
+#define RTC_TEST3 0x30 /* 32bit rtc test reg 3 */
+
+enum imx_rtc_type {
+ IMX1_RTC,
+ IMX21_RTC,
+};
+
+struct rtc_plat_data {
+ struct rtc_device *rtc;
+ void __iomem *ioaddr;
+ int irq;
+ struct clk *clk_ref;
+ struct clk *clk_ipg;
+ struct rtc_time g_rtc_alarm;
+ enum imx_rtc_type devtype;
+};
+
+static const struct of_device_id imx_rtc_dt_ids[] = {
+ { .compatible = "fsl,imx1-rtc", .data = (const void *)IMX1_RTC },
+ { .compatible = "fsl,imx21-rtc", .data = (const void *)IMX21_RTC },
+ {}
+};
+MODULE_DEVICE_TABLE(of, imx_rtc_dt_ids);
+
+static inline int is_imx1_rtc(struct rtc_plat_data *data)
+{
+ return data->devtype == IMX1_RTC;
+}
+
+/*
+ * This function is used to obtain the RTC time or the alarm value in
+ * second.
+ */
+static time64_t get_alarm_or_time(struct device *dev, int time_alarm)
+{
+ struct rtc_plat_data *pdata = dev_get_drvdata(dev);
+ void __iomem *ioaddr = pdata->ioaddr;
+ u32 day = 0, hr = 0, min = 0, sec = 0, hr_min = 0;
+
+ switch (time_alarm) {
+ case MXC_RTC_TIME:
+ day = readw(ioaddr + RTC_DAYR);
+ hr_min = readw(ioaddr + RTC_HOURMIN);
+ sec = readw(ioaddr + RTC_SECOND);
+ break;
+ case MXC_RTC_ALARM:
+ day = readw(ioaddr + RTC_DAYALARM);
+ hr_min = readw(ioaddr + RTC_ALRM_HM) & 0xffff;
+ sec = readw(ioaddr + RTC_ALRM_SEC);
+ break;
+ }
+
+ hr = hr_min >> 8;
+ min = hr_min & 0xff;
+
+ return ((((time64_t)day * 24 + hr) * 60) + min) * 60 + sec;
+}
+
+/*
+ * This function sets the RTC alarm value or the time value.
+ */
+static void set_alarm_or_time(struct device *dev, int time_alarm, time64_t time)
+{
+ u32 tod, day, hr, min, sec, temp;
+ struct rtc_plat_data *pdata = dev_get_drvdata(dev);
+ void __iomem *ioaddr = pdata->ioaddr;
+
+ day = div_s64_rem(time, 86400, &tod);
+
+ /* time is within a day now */
+ hr = tod / 3600;
+ tod -= hr * 3600;
+
+ /* time is within an hour now */
+ min = tod / 60;
+ sec = tod - min * 60;
+
+ temp = (hr << 8) + min;
+
+ switch (time_alarm) {
+ case MXC_RTC_TIME:
+ writew(day, ioaddr + RTC_DAYR);
+ writew(sec, ioaddr + RTC_SECOND);
+ writew(temp, ioaddr + RTC_HOURMIN);
+ break;
+ case MXC_RTC_ALARM:
+ writew(day, ioaddr + RTC_DAYALARM);
+ writew(sec, ioaddr + RTC_ALRM_SEC);
+ writew(temp, ioaddr + RTC_ALRM_HM);
+ break;
+ }
+}
+
+/*
+ * This function updates the RTC alarm registers and then clears all the
+ * interrupt status bits.
+ */
+static void rtc_update_alarm(struct device *dev, struct rtc_time *alrm)
+{
+ time64_t time;
+ struct rtc_plat_data *pdata = dev_get_drvdata(dev);
+ void __iomem *ioaddr = pdata->ioaddr;
+
+ time = rtc_tm_to_time64(alrm);
+
+ /* clear all the interrupt status bits */
+ writew(readw(ioaddr + RTC_RTCISR), ioaddr + RTC_RTCISR);
+ set_alarm_or_time(dev, MXC_RTC_ALARM, time);
+}
+
+static void mxc_rtc_irq_enable(struct device *dev, unsigned int bit,
+ unsigned int enabled)
+{
+ struct rtc_plat_data *pdata = dev_get_drvdata(dev);
+ void __iomem *ioaddr = pdata->ioaddr;
+ u32 reg;
+ unsigned long flags;
+
+ spin_lock_irqsave(&pdata->rtc->irq_lock, flags);
+ reg = readw(ioaddr + RTC_RTCIENR);
+
+ if (enabled)
+ reg |= bit;
+ else
+ reg &= ~bit;
+
+ writew(reg, ioaddr + RTC_RTCIENR);
+ spin_unlock_irqrestore(&pdata->rtc->irq_lock, flags);
+}
+
+/* This function is the RTC interrupt service routine. */
+static irqreturn_t mxc_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;
+ u32 status;
+ u32 events = 0;
+
+ spin_lock(&pdata->rtc->irq_lock);
+ status = readw(ioaddr + RTC_RTCISR) & readw(ioaddr + RTC_RTCIENR);
+ /* clear interrupt sources */
+ writew(status, ioaddr + RTC_RTCISR);
+
+ /* update irq data & counter */
+ if (status & RTC_ALM_BIT) {
+ events |= (RTC_AF | RTC_IRQF);
+ /* RTC alarm should be one-shot */
+ mxc_rtc_irq_enable(&pdev->dev, RTC_ALM_BIT, 0);
+ }
+
+ if (status & PIT_ALL_ON)
+ events |= (RTC_PF | RTC_IRQF);
+
+ rtc_update_irq(pdata->rtc, 1, events);
+ spin_unlock(&pdata->rtc->irq_lock);
+
+ return IRQ_HANDLED;
+}
+
+static int mxc_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+ mxc_rtc_irq_enable(dev, RTC_ALM_BIT, enabled);
+ return 0;
+}
+
+/*
+ * This function reads the current RTC time into tm in Gregorian date.
+ */
+static int mxc_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ time64_t val;
+
+ /* Avoid roll-over from reading the different registers */
+ do {
+ val = get_alarm_or_time(dev, MXC_RTC_TIME);
+ } while (val != get_alarm_or_time(dev, MXC_RTC_TIME));
+
+ rtc_time64_to_tm(val, tm);
+
+ return 0;
+}
+
+/*
+ * This function sets the internal RTC time based on tm in Gregorian date.
+ */
+static int mxc_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ time64_t time = rtc_tm_to_time64(tm);
+
+ /* Avoid roll-over from reading the different registers */
+ do {
+ set_alarm_or_time(dev, MXC_RTC_TIME, time);
+ } while (time != get_alarm_or_time(dev, MXC_RTC_TIME));
+
+ return 0;
+}
+
+/*
+ * This function reads the current alarm value into the passed in 'alrm'
+ * argument. It updates the alrm's pending field value based on the whether
+ * an alarm interrupt occurs or not.
+ */
+static int mxc_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct rtc_plat_data *pdata = dev_get_drvdata(dev);
+ void __iomem *ioaddr = pdata->ioaddr;
+
+ rtc_time64_to_tm(get_alarm_or_time(dev, MXC_RTC_ALARM), &alrm->time);
+ alrm->pending = ((readw(ioaddr + RTC_RTCISR) & RTC_ALM_BIT)) ? 1 : 0;
+
+ return 0;
+}
+
+/*
+ * This function sets the RTC alarm based on passed in alrm.
+ */
+static int mxc_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct rtc_plat_data *pdata = dev_get_drvdata(dev);
+
+ rtc_update_alarm(dev, &alrm->time);
+
+ memcpy(&pdata->g_rtc_alarm, &alrm->time, sizeof(struct rtc_time));
+ mxc_rtc_irq_enable(dev, RTC_ALM_BIT, alrm->enabled);
+
+ return 0;
+}
+
+/* RTC layer */
+static const struct rtc_class_ops mxc_rtc_ops = {
+ .read_time = mxc_rtc_read_time,
+ .set_time = mxc_rtc_set_time,
+ .read_alarm = mxc_rtc_read_alarm,
+ .set_alarm = mxc_rtc_set_alarm,
+ .alarm_irq_enable = mxc_rtc_alarm_irq_enable,
+};
+
+static int mxc_rtc_probe(struct platform_device *pdev)
+{
+ struct rtc_device *rtc;
+ struct rtc_plat_data *pdata = NULL;
+ u32 reg;
+ unsigned long rate;
+ int ret;
+
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata)
+ return -ENOMEM;
+
+ pdata->devtype = (uintptr_t)of_device_get_match_data(&pdev->dev);
+
+ pdata->ioaddr = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(pdata->ioaddr))
+ return PTR_ERR(pdata->ioaddr);
+
+ rtc = devm_rtc_allocate_device(&pdev->dev);
+ if (IS_ERR(rtc))
+ return PTR_ERR(rtc);
+
+ pdata->rtc = rtc;
+ rtc->ops = &mxc_rtc_ops;
+ if (is_imx1_rtc(pdata)) {
+ struct rtc_time tm;
+
+ /* 9bit days + hours minutes seconds */
+ rtc->range_max = (1 << 9) * 86400 - 1;
+
+ /*
+ * Set the start date as beginning of the current year. This can
+ * be overridden using device tree.
+ */
+ rtc_time64_to_tm(ktime_get_real_seconds(), &tm);
+ rtc->start_secs = mktime64(tm.tm_year, 1, 1, 0, 0, 0);
+ rtc->set_start_time = true;
+ } else {
+ /* 16bit days + hours minutes seconds */
+ rtc->range_max = (1 << 16) * 86400ULL - 1;
+ }
+
+ pdata->clk_ipg = devm_clk_get_enabled(&pdev->dev, "ipg");
+ if (IS_ERR(pdata->clk_ipg)) {
+ dev_err(&pdev->dev, "unable to get ipg clock!\n");
+ return PTR_ERR(pdata->clk_ipg);
+ }
+
+ pdata->clk_ref = devm_clk_get_enabled(&pdev->dev, "ref");
+ if (IS_ERR(pdata->clk_ref)) {
+ dev_err(&pdev->dev, "unable to get ref clock!\n");
+ return PTR_ERR(pdata->clk_ref);
+ }
+
+ rate = clk_get_rate(pdata->clk_ref);
+
+ if (rate == 32768)
+ reg = RTC_INPUT_CLK_32768HZ;
+ else if (rate == 32000)
+ reg = RTC_INPUT_CLK_32000HZ;
+ else if (rate == 38400)
+ reg = RTC_INPUT_CLK_38400HZ;
+ else {
+ dev_err(&pdev->dev, "rtc clock is not valid (%lu)\n", rate);
+ return -EINVAL;
+ }
+
+ reg |= RTC_ENABLE_BIT;
+ writew(reg, (pdata->ioaddr + RTC_RTCCTL));
+ if (((readw(pdata->ioaddr + RTC_RTCCTL)) & RTC_ENABLE_BIT) == 0) {
+ dev_err(&pdev->dev, "hardware module can't be enabled!\n");
+ return -EIO;
+ }
+
+ platform_set_drvdata(pdev, pdata);
+
+ /* Configure and enable the RTC */
+ pdata->irq = platform_get_irq(pdev, 0);
+
+ if (pdata->irq >= 0 &&
+ devm_request_irq(&pdev->dev, pdata->irq, mxc_rtc_interrupt,
+ IRQF_SHARED, pdev->name, pdev) < 0) {
+ dev_warn(&pdev->dev, "interrupt not available.\n");
+ pdata->irq = -1;
+ }
+
+ if (pdata->irq >= 0) {
+ device_init_wakeup(&pdev->dev, true);
+ ret = dev_pm_set_wake_irq(&pdev->dev, pdata->irq);
+ if (ret)
+ dev_err(&pdev->dev, "failed to enable irq wake\n");
+ }
+
+ ret = devm_rtc_register_device(rtc);
+
+ return ret;
+}
+
+static struct platform_driver mxc_rtc_driver = {
+ .driver = {
+ .name = "mxc_rtc",
+ .of_match_table = imx_rtc_dt_ids,
+ },
+ .probe = mxc_rtc_probe,
+};
+
+module_platform_driver(mxc_rtc_driver)
+
+MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
+MODULE_DESCRIPTION("RTC driver for Freescale MXC");
+MODULE_LICENSE("GPL");
+