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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-s32g.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-s32g.c')
-rw-r--r--drivers/rtc/rtc-s32g.c385
1 files changed, 385 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-s32g.c b/drivers/rtc/rtc-s32g.c
new file mode 100644
index 000000000..3a0818e97
--- /dev/null
+++ b/drivers/rtc/rtc-s32g.c
@@ -0,0 +1,385 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2025 NXP
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/iopoll.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+
+#define RTCC_OFFSET 0x4ul
+#define RTCS_OFFSET 0x8ul
+#define APIVAL_OFFSET 0x10ul
+
+/* RTCC fields */
+#define RTCC_CNTEN BIT(31)
+#define RTCC_APIEN BIT(15)
+#define RTCC_APIIE BIT(14)
+#define RTCC_CLKSEL_MASK GENMASK(13, 12)
+#define RTCC_DIV512EN BIT(11)
+#define RTCC_DIV32EN BIT(10)
+
+/* RTCS fields */
+#define RTCS_INV_API BIT(17)
+#define RTCS_APIF BIT(13)
+
+#define APIVAL_MAX_VAL GENMASK(31, 0)
+#define RTC_SYNCH_TIMEOUT (100 * USEC_PER_MSEC)
+
+/*
+ * S32G2 and S32G3 SoCs have RTC clock source1 reserved and
+ * should not be used.
+ */
+#define RTC_CLK_SRC1_RESERVED BIT(1)
+
+/*
+ * S32G RTC module has a 512 value and a 32 value hardware frequency
+ * divisors (DIV512 and DIV32) which could be used to achieve higher
+ * counter ranges by lowering the RTC frequency.
+ */
+enum {
+ DIV1 = 1,
+ DIV32 = 32,
+ DIV512 = 512,
+ DIV512_32 = 16384
+};
+
+static const char *const rtc_clk_src[] = {
+ "source0",
+ "source1",
+ "source2",
+ "source3"
+};
+
+struct rtc_priv {
+ struct rtc_device *rdev;
+ void __iomem *rtc_base;
+ struct clk *ipg;
+ struct clk *clk_src;
+ const struct rtc_soc_data *rtc_data;
+ u64 rtc_hz;
+ time64_t sleep_sec;
+ int irq;
+ u32 clk_src_idx;
+};
+
+struct rtc_soc_data {
+ u32 clk_div;
+ u32 reserved_clk_mask;
+};
+
+static const struct rtc_soc_data rtc_s32g2_data = {
+ .clk_div = DIV512_32,
+ .reserved_clk_mask = RTC_CLK_SRC1_RESERVED,
+};
+
+static irqreturn_t s32g_rtc_handler(int irq, void *dev)
+{
+ struct rtc_priv *priv = platform_get_drvdata(dev);
+ u32 status;
+
+ status = readl(priv->rtc_base + RTCS_OFFSET);
+
+ if (status & RTCS_APIF) {
+ writel(0x0, priv->rtc_base + APIVAL_OFFSET);
+ writel(status | RTCS_APIF, priv->rtc_base + RTCS_OFFSET);
+ }
+
+ rtc_update_irq(priv->rdev, 1, RTC_IRQF | RTC_AF);
+
+ return IRQ_HANDLED;
+}
+
+/*
+ * The function is not really getting time from the RTC since the S32G RTC
+ * has several limitations. Thus, to setup alarm use system time.
+ */
+static int s32g_rtc_read_time(struct device *dev,
+ struct rtc_time *tm)
+{
+ struct rtc_priv *priv = dev_get_drvdata(dev);
+ time64_t sec;
+
+ if (check_add_overflow(ktime_get_real_seconds(),
+ priv->sleep_sec, &sec))
+ return -ERANGE;
+
+ rtc_time64_to_tm(sec, tm);
+
+ return 0;
+}
+
+static int s32g_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct rtc_priv *priv = dev_get_drvdata(dev);
+ u32 rtcc, rtcs;
+
+ rtcc = readl(priv->rtc_base + RTCC_OFFSET);
+ rtcs = readl(priv->rtc_base + RTCS_OFFSET);
+
+ alrm->enabled = rtcc & RTCC_APIIE;
+ if (alrm->enabled)
+ alrm->pending = !(rtcs & RTCS_APIF);
+
+ return 0;
+}
+
+static int s32g_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+ struct rtc_priv *priv = dev_get_drvdata(dev);
+ u32 rtcc;
+
+ /* RTC API functionality is used both for triggering interrupts
+ * and as a wakeup event. Hence it should always be enabled.
+ */
+ rtcc = readl(priv->rtc_base + RTCC_OFFSET);
+ rtcc |= RTCC_APIEN | RTCC_APIIE;
+ writel(rtcc, priv->rtc_base + RTCC_OFFSET);
+
+ return 0;
+}
+
+static int s32g_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct rtc_priv *priv = dev_get_drvdata(dev);
+ unsigned long long cycles;
+ long long t_offset;
+ time64_t alrm_time;
+ u32 rtcs;
+ int ret;
+
+ alrm_time = rtc_tm_to_time64(&alrm->time);
+ t_offset = alrm_time - ktime_get_real_seconds() - priv->sleep_sec;
+ if (t_offset < 0)
+ return -ERANGE;
+
+ cycles = t_offset * priv->rtc_hz;
+ if (cycles > APIVAL_MAX_VAL)
+ return -ERANGE;
+
+ /* APIVAL could have been reset from the IRQ handler.
+ * Hence, we wait in case there is a synchronization process.
+ */
+ ret = read_poll_timeout(readl, rtcs, !(rtcs & RTCS_INV_API),
+ 0, RTC_SYNCH_TIMEOUT, false, priv->rtc_base + RTCS_OFFSET);
+ if (ret)
+ return ret;
+
+ writel(cycles, priv->rtc_base + APIVAL_OFFSET);
+
+ return read_poll_timeout(readl, rtcs, !(rtcs & RTCS_INV_API),
+ 0, RTC_SYNCH_TIMEOUT, false, priv->rtc_base + RTCS_OFFSET);
+}
+
+/*
+ * Disable the 32-bit free running counter.
+ * This allows Clock Source and Divisors selection
+ * to be performed without causing synchronization issues.
+ */
+static void s32g_rtc_disable(struct rtc_priv *priv)
+{
+ u32 rtcc = readl(priv->rtc_base + RTCC_OFFSET);
+
+ rtcc &= ~RTCC_CNTEN;
+ writel(rtcc, priv->rtc_base + RTCC_OFFSET);
+}
+
+static void s32g_rtc_enable(struct rtc_priv *priv)
+{
+ u32 rtcc = readl(priv->rtc_base + RTCC_OFFSET);
+
+ rtcc |= RTCC_CNTEN;
+ writel(rtcc, priv->rtc_base + RTCC_OFFSET);
+}
+
+static int rtc_clk_src_setup(struct rtc_priv *priv)
+{
+ u32 rtcc;
+
+ rtcc = FIELD_PREP(RTCC_CLKSEL_MASK, priv->clk_src_idx);
+
+ switch (priv->rtc_data->clk_div) {
+ case DIV512_32:
+ rtcc |= RTCC_DIV512EN;
+ rtcc |= RTCC_DIV32EN;
+ break;
+ case DIV512:
+ rtcc |= RTCC_DIV512EN;
+ break;
+ case DIV32:
+ rtcc |= RTCC_DIV32EN;
+ break;
+ case DIV1:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ rtcc |= RTCC_APIEN | RTCC_APIIE;
+ /*
+ * Make sure the CNTEN is 0 before we configure
+ * the clock source and dividers.
+ */
+ s32g_rtc_disable(priv);
+ writel(rtcc, priv->rtc_base + RTCC_OFFSET);
+ s32g_rtc_enable(priv);
+
+ return 0;
+}
+
+static const struct rtc_class_ops rtc_ops = {
+ .read_time = s32g_rtc_read_time,
+ .read_alarm = s32g_rtc_read_alarm,
+ .set_alarm = s32g_rtc_set_alarm,
+ .alarm_irq_enable = s32g_rtc_alarm_irq_enable,
+};
+
+static int rtc_clk_dts_setup(struct rtc_priv *priv,
+ struct device *dev)
+{
+ u32 i;
+
+ priv->ipg = devm_clk_get_enabled(dev, "ipg");
+ if (IS_ERR(priv->ipg))
+ return dev_err_probe(dev, PTR_ERR(priv->ipg),
+ "Failed to get 'ipg' clock\n");
+
+ for (i = 0; i < ARRAY_SIZE(rtc_clk_src); i++) {
+ if (priv->rtc_data->reserved_clk_mask & BIT(i))
+ return -EOPNOTSUPP;
+
+ priv->clk_src = devm_clk_get_enabled(dev, rtc_clk_src[i]);
+ if (!IS_ERR(priv->clk_src)) {
+ priv->clk_src_idx = i;
+ break;
+ }
+ }
+
+ if (IS_ERR(priv->clk_src))
+ return dev_err_probe(dev, PTR_ERR(priv->clk_src),
+ "Failed to get rtc module clock source\n");
+
+ return 0;
+}
+
+static int s32g_rtc_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct rtc_priv *priv;
+ unsigned long rtc_hz;
+ int ret;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->rtc_data = of_device_get_match_data(dev);
+ if (!priv->rtc_data)
+ return -ENODEV;
+
+ priv->rtc_base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(priv->rtc_base))
+ return PTR_ERR(priv->rtc_base);
+
+ device_init_wakeup(dev, true);
+
+ ret = rtc_clk_dts_setup(priv, dev);
+ if (ret)
+ return ret;
+
+ priv->rdev = devm_rtc_allocate_device(dev);
+ if (IS_ERR(priv->rdev))
+ return PTR_ERR(priv->rdev);
+
+ ret = rtc_clk_src_setup(priv);
+ if (ret)
+ return ret;
+
+ priv->irq = platform_get_irq(pdev, 0);
+ if (priv->irq < 0) {
+ ret = priv->irq;
+ goto disable_rtc;
+ }
+
+ rtc_hz = clk_get_rate(priv->clk_src);
+ if (!rtc_hz) {
+ dev_err(dev, "Failed to get RTC frequency\n");
+ ret = -EINVAL;
+ goto disable_rtc;
+ }
+
+ priv->rtc_hz = DIV_ROUND_UP(rtc_hz, priv->rtc_data->clk_div);
+
+ platform_set_drvdata(pdev, priv);
+ priv->rdev->ops = &rtc_ops;
+
+ ret = devm_request_irq(dev, priv->irq,
+ s32g_rtc_handler, 0, dev_name(dev), pdev);
+ if (ret) {
+ dev_err(dev, "Request interrupt %d failed, error: %d\n",
+ priv->irq, ret);
+ goto disable_rtc;
+ }
+
+ ret = devm_rtc_register_device(priv->rdev);
+ if (ret)
+ goto disable_rtc;
+
+ return 0;
+
+disable_rtc:
+ s32g_rtc_disable(priv);
+ return ret;
+}
+
+static int s32g_rtc_suspend(struct device *dev)
+{
+ struct rtc_priv *priv = dev_get_drvdata(dev);
+ u32 apival = readl(priv->rtc_base + APIVAL_OFFSET);
+
+ if (check_add_overflow(priv->sleep_sec, div64_u64(apival, priv->rtc_hz),
+ &priv->sleep_sec)) {
+ dev_warn(dev, "Overflow on sleep cycles occurred. Resetting to 0.\n");
+ priv->sleep_sec = 0;
+ }
+
+ return 0;
+}
+
+static int s32g_rtc_resume(struct device *dev)
+{
+ struct rtc_priv *priv = dev_get_drvdata(dev);
+
+ /* The transition from resume to run is a reset event.
+ * This leads to the RTC registers being reset after resume from
+ * suspend. It is uncommon, but this behaviour has been observed
+ * on S32G RTC after issuing a Suspend to RAM operation.
+ * Thus, reconfigure RTC registers on the resume path.
+ */
+ return rtc_clk_src_setup(priv);
+}
+
+static const struct of_device_id rtc_dt_ids[] = {
+ { .compatible = "nxp,s32g2-rtc", .data = &rtc_s32g2_data },
+ { /* sentinel */ },
+};
+
+static DEFINE_SIMPLE_DEV_PM_OPS(s32g_rtc_pm_ops,
+ s32g_rtc_suspend, s32g_rtc_resume);
+
+static struct platform_driver s32g_rtc_driver = {
+ .driver = {
+ .name = "s32g-rtc",
+ .pm = pm_sleep_ptr(&s32g_rtc_pm_ops),
+ .of_match_table = rtc_dt_ids,
+ },
+ .probe = s32g_rtc_probe,
+};
+module_platform_driver(s32g_rtc_driver);
+
+MODULE_AUTHOR("NXP");
+MODULE_DESCRIPTION("NXP RTC driver for S32G2/S32G3");
+MODULE_LICENSE("GPL");