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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-xgene.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-xgene.c')
-rw-r--r--drivers/rtc/rtc-xgene.c278
1 files changed, 278 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-xgene.c b/drivers/rtc/rtc-xgene.c
new file mode 100644
index 000000000..6660b664e
--- /dev/null
+++ b/drivers/rtc/rtc-xgene.c
@@ -0,0 +1,278 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * APM X-Gene SoC Real Time Clock Driver
+ *
+ * Copyright (c) 2014, Applied Micro Circuits Corporation
+ * Author: Rameshwar Prasad Sahu <rsahu@apm.com>
+ * Loc Ho <lho@apm.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/slab.h>
+
+/* RTC CSR Registers */
+#define RTC_CCVR 0x00
+#define RTC_CMR 0x04
+#define RTC_CLR 0x08
+#define RTC_CCR 0x0C
+#define RTC_CCR_IE BIT(0)
+#define RTC_CCR_MASK BIT(1)
+#define RTC_CCR_EN BIT(2)
+#define RTC_CCR_WEN BIT(3)
+#define RTC_STAT 0x10
+#define RTC_STAT_BIT BIT(0)
+#define RTC_RSTAT 0x14
+#define RTC_EOI 0x18
+#define RTC_VER 0x1C
+
+struct xgene_rtc_dev {
+ struct rtc_device *rtc;
+ void __iomem *csr_base;
+ struct clk *clk;
+ unsigned int irq_wake;
+ unsigned int irq_enabled;
+};
+
+static int xgene_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct xgene_rtc_dev *pdata = dev_get_drvdata(dev);
+
+ rtc_time64_to_tm(readl(pdata->csr_base + RTC_CCVR), tm);
+ return 0;
+}
+
+static int xgene_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct xgene_rtc_dev *pdata = dev_get_drvdata(dev);
+
+ /*
+ * NOTE: After the following write, the RTC_CCVR is only reflected
+ * after the update cycle of 1 seconds.
+ */
+ writel((u32)rtc_tm_to_time64(tm), pdata->csr_base + RTC_CLR);
+ readl(pdata->csr_base + RTC_CLR); /* Force a barrier */
+
+ return 0;
+}
+
+static int xgene_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct xgene_rtc_dev *pdata = dev_get_drvdata(dev);
+
+ /* If possible, CMR should be read here */
+ rtc_time64_to_tm(0, &alrm->time);
+ alrm->enabled = readl(pdata->csr_base + RTC_CCR) & RTC_CCR_IE;
+
+ return 0;
+}
+
+static int xgene_rtc_alarm_irq_enable(struct device *dev, u32 enabled)
+{
+ struct xgene_rtc_dev *pdata = dev_get_drvdata(dev);
+ u32 ccr;
+
+ ccr = readl(pdata->csr_base + RTC_CCR);
+ if (enabled) {
+ ccr &= ~RTC_CCR_MASK;
+ ccr |= RTC_CCR_IE;
+ } else {
+ ccr &= ~RTC_CCR_IE;
+ ccr |= RTC_CCR_MASK;
+ }
+ writel(ccr, pdata->csr_base + RTC_CCR);
+
+ return 0;
+}
+
+static int xgene_rtc_alarm_irq_enabled(struct device *dev)
+{
+ struct xgene_rtc_dev *pdata = dev_get_drvdata(dev);
+
+ return readl(pdata->csr_base + RTC_CCR) & RTC_CCR_IE ? 1 : 0;
+}
+
+static int xgene_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct xgene_rtc_dev *pdata = dev_get_drvdata(dev);
+
+ writel((u32)rtc_tm_to_time64(&alrm->time), pdata->csr_base + RTC_CMR);
+
+ xgene_rtc_alarm_irq_enable(dev, alrm->enabled);
+
+ return 0;
+}
+
+static const struct rtc_class_ops xgene_rtc_ops = {
+ .read_time = xgene_rtc_read_time,
+ .set_time = xgene_rtc_set_time,
+ .read_alarm = xgene_rtc_read_alarm,
+ .set_alarm = xgene_rtc_set_alarm,
+ .alarm_irq_enable = xgene_rtc_alarm_irq_enable,
+};
+
+static irqreturn_t xgene_rtc_interrupt(int irq, void *id)
+{
+ struct xgene_rtc_dev *pdata = id;
+
+ /* Check if interrupt asserted */
+ if (!(readl(pdata->csr_base + RTC_STAT) & RTC_STAT_BIT))
+ return IRQ_NONE;
+
+ /* Clear interrupt */
+ readl(pdata->csr_base + RTC_EOI);
+
+ rtc_update_irq(pdata->rtc, 1, RTC_IRQF | RTC_AF);
+
+ return IRQ_HANDLED;
+}
+
+static int xgene_rtc_probe(struct platform_device *pdev)
+{
+ struct xgene_rtc_dev *pdata;
+ int ret;
+ int irq;
+
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata)
+ return -ENOMEM;
+ platform_set_drvdata(pdev, pdata);
+
+ pdata->csr_base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(pdata->csr_base))
+ return PTR_ERR(pdata->csr_base);
+
+ pdata->rtc = devm_rtc_allocate_device(&pdev->dev);
+ if (IS_ERR(pdata->rtc))
+ return PTR_ERR(pdata->rtc);
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return irq;
+ ret = devm_request_irq(&pdev->dev, irq, xgene_rtc_interrupt, 0,
+ dev_name(&pdev->dev), pdata);
+ if (ret) {
+ dev_err(&pdev->dev, "Could not request IRQ\n");
+ return ret;
+ }
+
+ pdata->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(pdata->clk)) {
+ dev_err(&pdev->dev, "Couldn't get the clock for RTC\n");
+ return -ENODEV;
+ }
+ ret = clk_prepare_enable(pdata->clk);
+ if (ret)
+ return ret;
+
+ /* Turn on the clock and the crystal */
+ writel(RTC_CCR_EN, pdata->csr_base + RTC_CCR);
+
+ ret = device_init_wakeup(&pdev->dev, true);
+ if (ret) {
+ clk_disable_unprepare(pdata->clk);
+ return ret;
+ }
+
+ pdata->rtc->ops = &xgene_rtc_ops;
+ pdata->rtc->range_max = U32_MAX;
+
+ ret = devm_rtc_register_device(pdata->rtc);
+ if (ret) {
+ clk_disable_unprepare(pdata->clk);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void xgene_rtc_remove(struct platform_device *pdev)
+{
+ struct xgene_rtc_dev *pdata = platform_get_drvdata(pdev);
+
+ xgene_rtc_alarm_irq_enable(&pdev->dev, 0);
+ device_init_wakeup(&pdev->dev, false);
+ clk_disable_unprepare(pdata->clk);
+}
+
+static int __maybe_unused xgene_rtc_suspend(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct xgene_rtc_dev *pdata = platform_get_drvdata(pdev);
+ int irq;
+
+ irq = platform_get_irq(pdev, 0);
+
+ /*
+ * If this RTC alarm will be used for waking the system up,
+ * don't disable it of course. Else we just disable the alarm
+ * and await suspension.
+ */
+ if (device_may_wakeup(&pdev->dev)) {
+ if (!enable_irq_wake(irq))
+ pdata->irq_wake = 1;
+ } else {
+ pdata->irq_enabled = xgene_rtc_alarm_irq_enabled(dev);
+ xgene_rtc_alarm_irq_enable(dev, 0);
+ clk_disable_unprepare(pdata->clk);
+ }
+ return 0;
+}
+
+static int __maybe_unused xgene_rtc_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct xgene_rtc_dev *pdata = platform_get_drvdata(pdev);
+ int irq;
+ int rc;
+
+ irq = platform_get_irq(pdev, 0);
+
+ if (device_may_wakeup(&pdev->dev)) {
+ if (pdata->irq_wake) {
+ disable_irq_wake(irq);
+ pdata->irq_wake = 0;
+ }
+ } else {
+ rc = clk_prepare_enable(pdata->clk);
+ if (rc) {
+ dev_err(dev, "Unable to enable clock error %d\n", rc);
+ return rc;
+ }
+ xgene_rtc_alarm_irq_enable(dev, pdata->irq_enabled);
+ }
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(xgene_rtc_pm_ops, xgene_rtc_suspend, xgene_rtc_resume);
+
+#ifdef CONFIG_OF
+static const struct of_device_id xgene_rtc_of_match[] = {
+ {.compatible = "apm,xgene-rtc" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, xgene_rtc_of_match);
+#endif
+
+static struct platform_driver xgene_rtc_driver = {
+ .probe = xgene_rtc_probe,
+ .remove = xgene_rtc_remove,
+ .driver = {
+ .name = "xgene-rtc",
+ .pm = &xgene_rtc_pm_ops,
+ .of_match_table = of_match_ptr(xgene_rtc_of_match),
+ },
+};
+
+module_platform_driver(xgene_rtc_driver);
+
+MODULE_DESCRIPTION("APM X-Gene SoC RTC driver");
+MODULE_AUTHOR("Rameshwar Sahu <rsahu@apm.com>");
+MODULE_LICENSE("GPL");