diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /drivers/rtc/rtc-cadence.c | |
| download | linux-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-cadence.c')
| -rw-r--r-- | drivers/rtc/rtc-cadence.c | 412 |
1 files changed, 412 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-cadence.c b/drivers/rtc/rtc-cadence.c new file mode 100644 index 000000000..8634eea79 --- /dev/null +++ b/drivers/rtc/rtc-cadence.c @@ -0,0 +1,412 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Copyright 2019 Cadence + * + * Authors: + * Jan Kotas <jank@cadence.com> + */ + +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/of.h> +#include <linux/io.h> +#include <linux/rtc.h> +#include <linux/clk.h> +#include <linux/bcd.h> +#include <linux/bitfield.h> +#include <linux/interrupt.h> +#include <linux/pm_wakeirq.h> + +/* Registers */ +#define CDNS_RTC_CTLR 0x00 +#define CDNS_RTC_HMR 0x04 +#define CDNS_RTC_TIMR 0x08 +#define CDNS_RTC_CALR 0x0C +#define CDNS_RTC_TIMAR 0x10 +#define CDNS_RTC_CALAR 0x14 +#define CDNS_RTC_AENR 0x18 +#define CDNS_RTC_EFLR 0x1C +#define CDNS_RTC_IENR 0x20 +#define CDNS_RTC_IDISR 0x24 +#define CDNS_RTC_IMSKR 0x28 +#define CDNS_RTC_STSR 0x2C +#define CDNS_RTC_KRTCR 0x30 + +/* Control */ +#define CDNS_RTC_CTLR_TIME BIT(0) +#define CDNS_RTC_CTLR_CAL BIT(1) +#define CDNS_RTC_CTLR_TIME_CAL (CDNS_RTC_CTLR_TIME | CDNS_RTC_CTLR_CAL) + +/* Status */ +#define CDNS_RTC_STSR_VT BIT(0) +#define CDNS_RTC_STSR_VC BIT(1) +#define CDNS_RTC_STSR_VTA BIT(2) +#define CDNS_RTC_STSR_VCA BIT(3) +#define CDNS_RTC_STSR_VT_VC (CDNS_RTC_STSR_VT | CDNS_RTC_STSR_VC) +#define CDNS_RTC_STSR_VTA_VCA (CDNS_RTC_STSR_VTA | CDNS_RTC_STSR_VCA) + +/* Keep RTC */ +#define CDNS_RTC_KRTCR_KRTC BIT(0) + +/* Alarm, Event, Interrupt */ +#define CDNS_RTC_AEI_HOS BIT(0) +#define CDNS_RTC_AEI_SEC BIT(1) +#define CDNS_RTC_AEI_MIN BIT(2) +#define CDNS_RTC_AEI_HOUR BIT(3) +#define CDNS_RTC_AEI_DATE BIT(4) +#define CDNS_RTC_AEI_MNTH BIT(5) +#define CDNS_RTC_AEI_ALRM BIT(6) + +/* Time */ +#define CDNS_RTC_TIME_H GENMASK(7, 0) +#define CDNS_RTC_TIME_S GENMASK(14, 8) +#define CDNS_RTC_TIME_M GENMASK(22, 16) +#define CDNS_RTC_TIME_HR GENMASK(29, 24) +#define CDNS_RTC_TIME_PM BIT(30) +#define CDNS_RTC_TIME_CH BIT(31) + +/* Calendar */ +#define CDNS_RTC_CAL_DAY GENMASK(2, 0) +#define CDNS_RTC_CAL_M GENMASK(7, 3) +#define CDNS_RTC_CAL_D GENMASK(13, 8) +#define CDNS_RTC_CAL_Y GENMASK(23, 16) +#define CDNS_RTC_CAL_C GENMASK(29, 24) +#define CDNS_RTC_CAL_CH BIT(31) + +#define CDNS_RTC_MAX_REGS_TRIES 3 + +struct cdns_rtc { + struct rtc_device *rtc_dev; + struct clk *pclk; + struct clk *ref_clk; + void __iomem *regs; + int irq; +}; + +static void cdns_rtc_set_enabled(struct cdns_rtc *crtc, bool enabled) +{ + u32 reg = enabled ? 0x0 : CDNS_RTC_CTLR_TIME_CAL; + + writel(reg, crtc->regs + CDNS_RTC_CTLR); +} + +static bool cdns_rtc_get_enabled(struct cdns_rtc *crtc) +{ + return !(readl(crtc->regs + CDNS_RTC_CTLR) & CDNS_RTC_CTLR_TIME_CAL); +} + +static irqreturn_t cdns_rtc_irq_handler(int irq, void *id) +{ + struct device *dev = id; + struct cdns_rtc *crtc = dev_get_drvdata(dev); + + /* Reading the register clears it */ + if (!(readl(crtc->regs + CDNS_RTC_EFLR) & CDNS_RTC_AEI_ALRM)) + return IRQ_NONE; + + rtc_update_irq(crtc->rtc_dev, 1, RTC_IRQF | RTC_AF); + return IRQ_HANDLED; +} + +static u32 cdns_rtc_time2reg(struct rtc_time *tm) +{ + return FIELD_PREP(CDNS_RTC_TIME_S, bin2bcd(tm->tm_sec)) + | FIELD_PREP(CDNS_RTC_TIME_M, bin2bcd(tm->tm_min)) + | FIELD_PREP(CDNS_RTC_TIME_HR, bin2bcd(tm->tm_hour)); +} + +static void cdns_rtc_reg2time(u32 reg, struct rtc_time *tm) +{ + tm->tm_sec = bcd2bin(FIELD_GET(CDNS_RTC_TIME_S, reg)); + tm->tm_min = bcd2bin(FIELD_GET(CDNS_RTC_TIME_M, reg)); + tm->tm_hour = bcd2bin(FIELD_GET(CDNS_RTC_TIME_HR, reg)); +} + +static int cdns_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct cdns_rtc *crtc = dev_get_drvdata(dev); + u32 reg; + + /* If the RTC is disabled, assume the values are invalid */ + if (!cdns_rtc_get_enabled(crtc)) + return -EINVAL; + + cdns_rtc_set_enabled(crtc, false); + + reg = readl(crtc->regs + CDNS_RTC_TIMR); + cdns_rtc_reg2time(reg, tm); + + reg = readl(crtc->regs + CDNS_RTC_CALR); + tm->tm_mday = bcd2bin(FIELD_GET(CDNS_RTC_CAL_D, reg)); + tm->tm_mon = bcd2bin(FIELD_GET(CDNS_RTC_CAL_M, reg)) - 1; + tm->tm_year = bcd2bin(FIELD_GET(CDNS_RTC_CAL_Y, reg)) + + bcd2bin(FIELD_GET(CDNS_RTC_CAL_C, reg)) * 100 - 1900; + tm->tm_wday = bcd2bin(FIELD_GET(CDNS_RTC_CAL_DAY, reg)) - 1; + + cdns_rtc_set_enabled(crtc, true); + return 0; +} + +static int cdns_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct cdns_rtc *crtc = dev_get_drvdata(dev); + u32 timr, calr, stsr; + int ret = -EIO; + int year = tm->tm_year + 1900; + int tries; + + cdns_rtc_set_enabled(crtc, false); + + timr = cdns_rtc_time2reg(tm); + + calr = FIELD_PREP(CDNS_RTC_CAL_D, bin2bcd(tm->tm_mday)) + | FIELD_PREP(CDNS_RTC_CAL_M, bin2bcd(tm->tm_mon + 1)) + | FIELD_PREP(CDNS_RTC_CAL_Y, bin2bcd(year % 100)) + | FIELD_PREP(CDNS_RTC_CAL_C, bin2bcd(year / 100)) + | FIELD_PREP(CDNS_RTC_CAL_DAY, tm->tm_wday + 1); + + /* Update registers, check valid flags */ + for (tries = 0; tries < CDNS_RTC_MAX_REGS_TRIES; tries++) { + writel(timr, crtc->regs + CDNS_RTC_TIMR); + writel(calr, crtc->regs + CDNS_RTC_CALR); + stsr = readl(crtc->regs + CDNS_RTC_STSR); + + if ((stsr & CDNS_RTC_STSR_VT_VC) == CDNS_RTC_STSR_VT_VC) { + ret = 0; + break; + } + } + + cdns_rtc_set_enabled(crtc, true); + return ret; +} + +static int cdns_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct cdns_rtc *crtc = dev_get_drvdata(dev); + + if (enabled) { + writel((CDNS_RTC_AEI_SEC | CDNS_RTC_AEI_MIN | CDNS_RTC_AEI_HOUR + | CDNS_RTC_AEI_DATE | CDNS_RTC_AEI_MNTH), + crtc->regs + CDNS_RTC_AENR); + writel(CDNS_RTC_AEI_ALRM, crtc->regs + CDNS_RTC_IENR); + } else { + writel(0, crtc->regs + CDNS_RTC_AENR); + writel(CDNS_RTC_AEI_ALRM, crtc->regs + CDNS_RTC_IDISR); + } + + return 0; +} + +static int cdns_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) +{ + struct cdns_rtc *crtc = dev_get_drvdata(dev); + u32 reg; + + reg = readl(crtc->regs + CDNS_RTC_TIMAR); + cdns_rtc_reg2time(reg, &alarm->time); + + reg = readl(crtc->regs + CDNS_RTC_CALAR); + alarm->time.tm_mday = bcd2bin(FIELD_GET(CDNS_RTC_CAL_D, reg)); + alarm->time.tm_mon = bcd2bin(FIELD_GET(CDNS_RTC_CAL_M, reg)) - 1; + + return 0; +} + +static int cdns_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) +{ + struct cdns_rtc *crtc = dev_get_drvdata(dev); + int ret = -EIO; + int tries; + u32 timar, calar, stsr; + + cdns_rtc_alarm_irq_enable(dev, 0); + + timar = cdns_rtc_time2reg(&alarm->time); + calar = FIELD_PREP(CDNS_RTC_CAL_D, bin2bcd(alarm->time.tm_mday)) + | FIELD_PREP(CDNS_RTC_CAL_M, bin2bcd(alarm->time.tm_mon + 1)); + + /* Update registers, check valid alarm flags */ + for (tries = 0; tries < CDNS_RTC_MAX_REGS_TRIES; tries++) { + writel(timar, crtc->regs + CDNS_RTC_TIMAR); + writel(calar, crtc->regs + CDNS_RTC_CALAR); + stsr = readl(crtc->regs + CDNS_RTC_STSR); + + if ((stsr & CDNS_RTC_STSR_VTA_VCA) == CDNS_RTC_STSR_VTA_VCA) { + ret = 0; + break; + } + } + + if (!ret) + cdns_rtc_alarm_irq_enable(dev, alarm->enabled); + return ret; +} + +static const struct rtc_class_ops cdns_rtc_ops = { + .read_time = cdns_rtc_read_time, + .set_time = cdns_rtc_set_time, + .read_alarm = cdns_rtc_read_alarm, + .set_alarm = cdns_rtc_set_alarm, + .alarm_irq_enable = cdns_rtc_alarm_irq_enable, +}; + +static int cdns_rtc_probe(struct platform_device *pdev) +{ + struct cdns_rtc *crtc; + int ret; + unsigned long ref_clk_freq; + + crtc = devm_kzalloc(&pdev->dev, sizeof(*crtc), GFP_KERNEL); + if (!crtc) + return -ENOMEM; + + crtc->regs = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(crtc->regs)) + return PTR_ERR(crtc->regs); + + crtc->irq = platform_get_irq(pdev, 0); + if (crtc->irq < 0) + return -EINVAL; + + crtc->pclk = devm_clk_get(&pdev->dev, "pclk"); + if (IS_ERR(crtc->pclk)) { + ret = PTR_ERR(crtc->pclk); + dev_err(&pdev->dev, + "Failed to retrieve the peripheral clock, %d\n", ret); + return ret; + } + + crtc->ref_clk = devm_clk_get(&pdev->dev, "ref_clk"); + if (IS_ERR(crtc->ref_clk)) { + ret = PTR_ERR(crtc->ref_clk); + dev_err(&pdev->dev, + "Failed to retrieve the reference clock, %d\n", ret); + return ret; + } + + crtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(crtc->rtc_dev)) + return PTR_ERR(crtc->rtc_dev); + + platform_set_drvdata(pdev, crtc); + + ret = clk_prepare_enable(crtc->pclk); + if (ret) { + dev_err(&pdev->dev, + "Failed to enable the peripheral clock, %d\n", ret); + return ret; + } + + ret = clk_prepare_enable(crtc->ref_clk); + if (ret) { + dev_err(&pdev->dev, + "Failed to enable the reference clock, %d\n", ret); + goto err_disable_pclk; + } + + ref_clk_freq = clk_get_rate(crtc->ref_clk); + if ((ref_clk_freq != 1) && (ref_clk_freq != 100)) { + dev_err(&pdev->dev, + "Invalid reference clock frequency %lu Hz.\n", + ref_clk_freq); + ret = -EINVAL; + goto err_disable_ref_clk; + } + + ret = devm_request_irq(&pdev->dev, crtc->irq, + cdns_rtc_irq_handler, 0, + dev_name(&pdev->dev), &pdev->dev); + if (ret) { + dev_err(&pdev->dev, + "Failed to request interrupt for the device, %d\n", + ret); + goto err_disable_ref_clk; + } + + /* The RTC supports 01.01.1900 - 31.12.2999 */ + crtc->rtc_dev->range_min = mktime64(1900, 1, 1, 0, 0, 0); + crtc->rtc_dev->range_max = mktime64(2999, 12, 31, 23, 59, 59); + + crtc->rtc_dev->ops = &cdns_rtc_ops; + device_init_wakeup(&pdev->dev, true); + + /* Always use 24-hour mode and keep the RTC values */ + writel(0, crtc->regs + CDNS_RTC_HMR); + writel(CDNS_RTC_KRTCR_KRTC, crtc->regs + CDNS_RTC_KRTCR); + + ret = devm_rtc_register_device(crtc->rtc_dev); + if (ret) + goto err_disable_wakeup; + + return 0; + +err_disable_wakeup: + device_init_wakeup(&pdev->dev, false); + +err_disable_ref_clk: + clk_disable_unprepare(crtc->ref_clk); + +err_disable_pclk: + clk_disable_unprepare(crtc->pclk); + + return ret; +} + +static void cdns_rtc_remove(struct platform_device *pdev) +{ + struct cdns_rtc *crtc = platform_get_drvdata(pdev); + + cdns_rtc_alarm_irq_enable(&pdev->dev, 0); + device_init_wakeup(&pdev->dev, false); + + clk_disable_unprepare(crtc->pclk); + clk_disable_unprepare(crtc->ref_clk); +} + +#ifdef CONFIG_PM_SLEEP +static int cdns_rtc_suspend(struct device *dev) +{ + struct cdns_rtc *crtc = dev_get_drvdata(dev); + + if (device_may_wakeup(dev)) + enable_irq_wake(crtc->irq); + + return 0; +} + +static int cdns_rtc_resume(struct device *dev) +{ + struct cdns_rtc *crtc = dev_get_drvdata(dev); + + if (device_may_wakeup(dev)) + disable_irq_wake(crtc->irq); + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(cdns_rtc_pm_ops, cdns_rtc_suspend, cdns_rtc_resume); + +static const struct of_device_id cdns_rtc_of_match[] = { + { .compatible = "cdns,rtc-r109v3" }, + { }, +}; +MODULE_DEVICE_TABLE(of, cdns_rtc_of_match); + +static struct platform_driver cdns_rtc_driver = { + .driver = { + .name = "cdns-rtc", + .of_match_table = cdns_rtc_of_match, + .pm = &cdns_rtc_pm_ops, + }, + .probe = cdns_rtc_probe, + .remove = cdns_rtc_remove, +}; +module_platform_driver(cdns_rtc_driver); + +MODULE_AUTHOR("Jan Kotas <jank@cadence.com>"); +MODULE_DESCRIPTION("Cadence RTC driver"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:cdns-rtc"); |
