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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/clocksource/timer-stm32-lp.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/clocksource/timer-stm32-lp.c')
-rw-r--r--drivers/clocksource/timer-stm32-lp.c292
1 files changed, 292 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-stm32-lp.c b/drivers/clocksource/timer-stm32-lp.c
new file mode 100644
index 000000000..3d804128c
--- /dev/null
+++ b/drivers/clocksource/timer-stm32-lp.c
@@ -0,0 +1,292 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) STMicroelectronics 2019 - All Rights Reserved
+ * Authors: Benjamin Gaignard <benjamin.gaignard@st.com> for STMicroelectronics.
+ * Pascal Paillet <p.paillet@st.com> for STMicroelectronics.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/stm32-lptimer.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/pm_wakeirq.h>
+
+#define CFGR_PSC_OFFSET 9
+#define STM32_LP_RATING 1000
+#define STM32_TARGET_CLKRATE (32000 * HZ)
+#define STM32_LP_MAX_PSC 7
+
+struct stm32_lp_private {
+ struct regmap *reg;
+ struct clock_event_device clkevt;
+ unsigned long period;
+ u32 psc;
+ struct device *dev;
+ struct clk *clk;
+ u32 version;
+};
+
+static struct stm32_lp_private*
+to_priv(struct clock_event_device *clkevt)
+{
+ return container_of(clkevt, struct stm32_lp_private, clkevt);
+}
+
+static int stm32_clkevent_lp_shutdown(struct clock_event_device *clkevt)
+{
+ struct stm32_lp_private *priv = to_priv(clkevt);
+
+ regmap_write(priv->reg, STM32_LPTIM_CR, 0);
+ regmap_write(priv->reg, STM32_LPTIM_IER, 0);
+ /* clear pending flags */
+ regmap_write(priv->reg, STM32_LPTIM_ICR, STM32_LPTIM_ARRMCF);
+
+ return 0;
+}
+
+static int stm32mp25_clkevent_lp_set_evt(struct stm32_lp_private *priv, unsigned long evt)
+{
+ int ret;
+ u32 val;
+
+ regmap_read(priv->reg, STM32_LPTIM_CR, &val);
+ if (!FIELD_GET(STM32_LPTIM_ENABLE, val)) {
+ /* Enable LPTIMER to be able to write into IER and ARR registers */
+ regmap_write(priv->reg, STM32_LPTIM_CR, STM32_LPTIM_ENABLE);
+ /*
+ * After setting the ENABLE bit, a delay of two counter clock cycles is needed
+ * before the LPTIM is actually enabled. For 32KHz rate, this makes approximately
+ * 62.5 micro-seconds, round it up.
+ */
+ udelay(63);
+ }
+ /* set next event counter */
+ regmap_write(priv->reg, STM32_LPTIM_ARR, evt);
+ /* enable ARR interrupt */
+ regmap_write(priv->reg, STM32_LPTIM_IER, STM32_LPTIM_ARRMIE);
+
+ /* Poll DIEROK and ARROK to ensure register access has completed */
+ ret = regmap_read_poll_timeout_atomic(priv->reg, STM32_LPTIM_ISR, val,
+ (val & STM32_LPTIM_DIEROK_ARROK) ==
+ STM32_LPTIM_DIEROK_ARROK,
+ 10, 500);
+ if (ret) {
+ dev_err(priv->dev, "access to LPTIM timed out\n");
+ /* Disable LPTIMER */
+ regmap_write(priv->reg, STM32_LPTIM_CR, 0);
+ return ret;
+ }
+ /* Clear DIEROK and ARROK flags */
+ regmap_write(priv->reg, STM32_LPTIM_ICR, STM32_LPTIM_DIEROKCF_ARROKCF);
+
+ return 0;
+}
+
+static void stm32_clkevent_lp_set_evt(struct stm32_lp_private *priv, unsigned long evt)
+{
+ /* disable LPTIMER to be able to write into IER register*/
+ regmap_write(priv->reg, STM32_LPTIM_CR, 0);
+ /* enable ARR interrupt */
+ regmap_write(priv->reg, STM32_LPTIM_IER, STM32_LPTIM_ARRMIE);
+ /* enable LPTIMER to be able to write into ARR register */
+ regmap_write(priv->reg, STM32_LPTIM_CR, STM32_LPTIM_ENABLE);
+ /* set next event counter */
+ regmap_write(priv->reg, STM32_LPTIM_ARR, evt);
+}
+
+static int stm32_clkevent_lp_set_timer(unsigned long evt,
+ struct clock_event_device *clkevt,
+ int is_periodic)
+{
+ struct stm32_lp_private *priv = to_priv(clkevt);
+ int ret;
+
+ if (priv->version == STM32_LPTIM_VERR_23) {
+ ret = stm32mp25_clkevent_lp_set_evt(priv, evt);
+ if (ret)
+ return ret;
+ } else {
+ stm32_clkevent_lp_set_evt(priv, evt);
+ }
+
+ /* start counter */
+ if (is_periodic)
+ regmap_write(priv->reg, STM32_LPTIM_CR,
+ STM32_LPTIM_CNTSTRT | STM32_LPTIM_ENABLE);
+ else
+ regmap_write(priv->reg, STM32_LPTIM_CR,
+ STM32_LPTIM_SNGSTRT | STM32_LPTIM_ENABLE);
+
+ return 0;
+}
+
+static int stm32_clkevent_lp_set_next_event(unsigned long evt,
+ struct clock_event_device *clkevt)
+{
+ return stm32_clkevent_lp_set_timer(evt, clkevt,
+ clockevent_state_periodic(clkevt));
+}
+
+static int stm32_clkevent_lp_set_periodic(struct clock_event_device *clkevt)
+{
+ struct stm32_lp_private *priv = to_priv(clkevt);
+
+ return stm32_clkevent_lp_set_timer(priv->period, clkevt, true);
+}
+
+static int stm32_clkevent_lp_set_oneshot(struct clock_event_device *clkevt)
+{
+ struct stm32_lp_private *priv = to_priv(clkevt);
+
+ return stm32_clkevent_lp_set_timer(priv->period, clkevt, false);
+}
+
+static irqreturn_t stm32_clkevent_lp_irq_handler(int irq, void *dev_id)
+{
+ struct clock_event_device *clkevt = (struct clock_event_device *)dev_id;
+ struct stm32_lp_private *priv = to_priv(clkevt);
+
+ regmap_write(priv->reg, STM32_LPTIM_ICR, STM32_LPTIM_ARRMCF);
+
+ if (clkevt->event_handler)
+ clkevt->event_handler(clkevt);
+
+ return IRQ_HANDLED;
+}
+
+static void stm32_clkevent_lp_set_prescaler(struct stm32_lp_private *priv,
+ unsigned long *rate)
+{
+ int i;
+
+ for (i = 0; i <= STM32_LP_MAX_PSC; i++) {
+ if (DIV_ROUND_CLOSEST(*rate, 1 << i) < STM32_TARGET_CLKRATE)
+ break;
+ }
+
+ regmap_write(priv->reg, STM32_LPTIM_CFGR, i << CFGR_PSC_OFFSET);
+
+ /* Adjust rate and period given the prescaler value */
+ *rate = DIV_ROUND_CLOSEST(*rate, (1 << i));
+ priv->period = DIV_ROUND_UP(*rate, HZ);
+ priv->psc = i;
+}
+
+static void stm32_clkevent_lp_suspend(struct clock_event_device *clkevt)
+{
+ struct stm32_lp_private *priv = to_priv(clkevt);
+
+ stm32_clkevent_lp_shutdown(clkevt);
+
+ /* balance clk_prepare_enable() from the probe */
+ clk_disable_unprepare(priv->clk);
+}
+
+static void stm32_clkevent_lp_resume(struct clock_event_device *clkevt)
+{
+ struct stm32_lp_private *priv = to_priv(clkevt);
+
+ clk_prepare_enable(priv->clk);
+
+ /* restore prescaler */
+ regmap_write(priv->reg, STM32_LPTIM_CFGR, priv->psc << CFGR_PSC_OFFSET);
+}
+
+static void stm32_clkevent_lp_init(struct stm32_lp_private *priv,
+ struct device_node *np, unsigned long rate)
+{
+ priv->clkevt.name = np->full_name;
+ priv->clkevt.cpumask = cpu_possible_mask;
+ priv->clkevt.features = CLOCK_EVT_FEAT_PERIODIC |
+ CLOCK_EVT_FEAT_ONESHOT;
+ priv->clkevt.set_state_shutdown = stm32_clkevent_lp_shutdown;
+ priv->clkevt.set_state_periodic = stm32_clkevent_lp_set_periodic;
+ priv->clkevt.set_state_oneshot = stm32_clkevent_lp_set_oneshot;
+ priv->clkevt.set_next_event = stm32_clkevent_lp_set_next_event;
+ priv->clkevt.rating = STM32_LP_RATING;
+ priv->clkevt.suspend = stm32_clkevent_lp_suspend;
+ priv->clkevt.resume = stm32_clkevent_lp_resume;
+ priv->clkevt.owner = THIS_MODULE;
+
+ clockevents_config_and_register(&priv->clkevt, rate, 0x1,
+ STM32_LPTIM_MAX_ARR);
+}
+
+static int stm32_clkevent_lp_probe(struct platform_device *pdev)
+{
+ struct stm32_lptimer *ddata = dev_get_drvdata(pdev->dev.parent);
+ struct stm32_lp_private *priv;
+ unsigned long rate;
+ int ret, irq;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->reg = ddata->regmap;
+ priv->version = ddata->version;
+ priv->clk = ddata->clk;
+ ret = clk_prepare_enable(priv->clk);
+ if (ret)
+ return -EINVAL;
+
+ rate = clk_get_rate(priv->clk);
+ if (!rate) {
+ ret = -EINVAL;
+ goto out_clk_disable;
+ }
+
+ irq = platform_get_irq(to_platform_device(pdev->dev.parent), 0);
+ if (irq <= 0) {
+ ret = irq;
+ goto out_clk_disable;
+ }
+
+ if (of_property_read_bool(pdev->dev.parent->of_node, "wakeup-source")) {
+ device_set_wakeup_capable(&pdev->dev, true);
+
+ ret = dev_pm_set_wake_irq(&pdev->dev, irq);
+ if (ret)
+ goto out_clk_disable;
+ }
+
+ ret = devm_request_irq(&pdev->dev, irq, stm32_clkevent_lp_irq_handler,
+ IRQF_TIMER, pdev->name, &priv->clkevt);
+ if (ret)
+ goto out_clk_disable;
+
+ stm32_clkevent_lp_set_prescaler(priv, &rate);
+
+ stm32_clkevent_lp_init(priv, pdev->dev.parent->of_node, rate);
+
+ priv->dev = &pdev->dev;
+
+ return 0;
+
+out_clk_disable:
+ clk_disable_unprepare(priv->clk);
+ return ret;
+}
+
+static const struct of_device_id stm32_clkevent_lp_of_match[] = {
+ { .compatible = "st,stm32-lptimer-timer", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, stm32_clkevent_lp_of_match);
+
+static struct platform_driver stm32_clkevent_lp_driver = {
+ .probe = stm32_clkevent_lp_probe,
+ .driver = {
+ .name = "stm32-lptimer-timer",
+ .of_match_table = stm32_clkevent_lp_of_match,
+ .suppress_bind_attrs = true,
+ },
+};
+module_platform_driver(stm32_clkevent_lp_driver);
+
+MODULE_DESCRIPTION("STMicroelectronics STM32 clockevent low power driver");