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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-gxp.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-gxp.c')
-rw-r--r--drivers/clocksource/timer-gxp.c215
1 files changed, 215 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-gxp.c b/drivers/clocksource/timer-gxp.c
new file mode 100644
index 000000000..1becc9433
--- /dev/null
+++ b/drivers/clocksource/timer-gxp.c
@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2022 Hewlett-Packard Enterprise Development Company, L.P. */
+
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/interrupt.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/sched_clock.h>
+
+#define TIMER0_FREQ 1000000
+#define GXP_TIMER_CNT_OFS 0x00
+#define GXP_TIMESTAMP_OFS 0x08
+#define GXP_TIMER_CTRL_OFS 0x14
+
+/* TCS Stands for Timer Control/Status: these are masks to be used in */
+/* the Timer Count Registers */
+#define MASK_TCS_ENABLE 0x01
+#define MASK_TCS_PERIOD 0x02
+#define MASK_TCS_RELOAD 0x04
+#define MASK_TCS_TC 0x80
+
+struct gxp_timer {
+ void __iomem *counter;
+ void __iomem *control;
+ struct clock_event_device evt;
+};
+
+static struct gxp_timer *gxp_timer;
+
+static void __iomem *system_clock __ro_after_init;
+
+static inline struct gxp_timer *to_gxp_timer(struct clock_event_device *evt_dev)
+{
+ return container_of(evt_dev, struct gxp_timer, evt);
+}
+
+static u64 notrace gxp_sched_read(void)
+{
+ return readl_relaxed(system_clock);
+}
+
+static int gxp_time_set_next_event(unsigned long event, struct clock_event_device *evt_dev)
+{
+ struct gxp_timer *timer = to_gxp_timer(evt_dev);
+
+ /* Stop counting and disable interrupt before updating */
+ writeb_relaxed(MASK_TCS_TC, timer->control);
+ writel_relaxed(event, timer->counter);
+ writeb_relaxed(MASK_TCS_TC | MASK_TCS_ENABLE, timer->control);
+
+ return 0;
+}
+
+static irqreturn_t gxp_timer_interrupt(int irq, void *dev_id)
+{
+ struct gxp_timer *timer = (struct gxp_timer *)dev_id;
+
+ if (!(readb_relaxed(timer->control) & MASK_TCS_TC))
+ return IRQ_NONE;
+
+ writeb_relaxed(MASK_TCS_TC, timer->control);
+
+ timer->evt.event_handler(&timer->evt);
+
+ return IRQ_HANDLED;
+}
+
+static int __init gxp_timer_init(struct device_node *node)
+{
+ void __iomem *base;
+ struct clk *clk;
+ u32 freq;
+ int ret, irq;
+
+ gxp_timer = kzalloc_obj(*gxp_timer);
+ if (!gxp_timer) {
+ ret = -ENOMEM;
+ pr_err("Can't allocate gxp_timer");
+ return ret;
+ }
+
+ clk = of_clk_get(node, 0);
+ if (IS_ERR(clk)) {
+ ret = PTR_ERR(clk);
+ pr_err("%pOFn clock not found: %d\n", node, ret);
+ goto err_free;
+ }
+
+ ret = clk_prepare_enable(clk);
+ if (ret) {
+ pr_err("%pOFn clock enable failed: %d\n", node, ret);
+ goto err_clk_enable;
+ }
+
+ base = of_iomap(node, 0);
+ if (!base) {
+ ret = -ENXIO;
+ pr_err("Can't map timer base registers");
+ goto err_iomap;
+ }
+
+ /* Set the offsets to the clock register and timer registers */
+ gxp_timer->counter = base + GXP_TIMER_CNT_OFS;
+ gxp_timer->control = base + GXP_TIMER_CTRL_OFS;
+ system_clock = base + GXP_TIMESTAMP_OFS;
+
+ gxp_timer->evt.name = node->name;
+ gxp_timer->evt.rating = 300;
+ gxp_timer->evt.features = CLOCK_EVT_FEAT_ONESHOT;
+ gxp_timer->evt.set_next_event = gxp_time_set_next_event;
+ gxp_timer->evt.cpumask = cpumask_of(0);
+
+ irq = irq_of_parse_and_map(node, 0);
+ if (irq <= 0) {
+ ret = -EINVAL;
+ pr_err("GXP Timer Can't parse IRQ %d", irq);
+ goto err_exit;
+ }
+
+ freq = clk_get_rate(clk);
+
+ ret = clocksource_mmio_init(system_clock, node->name, freq,
+ 300, 32, clocksource_mmio_readl_up);
+ if (ret) {
+ pr_err("%pOFn init clocksource failed: %d", node, ret);
+ goto err_exit;
+ }
+
+ sched_clock_register(gxp_sched_read, 32, freq);
+
+ irq = irq_of_parse_and_map(node, 0);
+ if (irq <= 0) {
+ ret = -EINVAL;
+ pr_err("%pOFn Can't parse IRQ %d", node, irq);
+ goto err_exit;
+ }
+
+ clockevents_config_and_register(&gxp_timer->evt, TIMER0_FREQ,
+ 0xf, 0xffffffff);
+
+ ret = request_irq(irq, gxp_timer_interrupt, IRQF_TIMER | IRQF_SHARED,
+ node->name, gxp_timer);
+ if (ret) {
+ pr_err("%pOFn request_irq() failed: %d", node, ret);
+ goto err_exit;
+ }
+
+ pr_debug("gxp: system timer (irq = %d)\n", irq);
+ return 0;
+
+err_exit:
+ iounmap(base);
+err_iomap:
+ clk_disable_unprepare(clk);
+err_clk_enable:
+ clk_put(clk);
+err_free:
+ kfree(gxp_timer);
+ return ret;
+}
+
+/*
+ * This probe gets called after the timer is already up and running. This will create
+ * the watchdog device as a child since the registers are shared.
+ */
+
+static int gxp_timer_probe(struct platform_device *pdev)
+{
+ struct platform_device *gxp_watchdog_device;
+ struct device *dev = &pdev->dev;
+ int ret;
+
+ if (!gxp_timer) {
+ pr_err("Gxp Timer not initialized, cannot create watchdog");
+ return -ENOMEM;
+ }
+
+ gxp_watchdog_device = platform_device_alloc("gxp-wdt", -1);
+ if (!gxp_watchdog_device) {
+ pr_err("Timer failed to allocate gxp-wdt");
+ return -ENOMEM;
+ }
+
+ /* Pass the base address (counter) as platform data and nothing else */
+ gxp_watchdog_device->dev.platform_data = gxp_timer->counter;
+ gxp_watchdog_device->dev.parent = dev;
+
+ ret = platform_device_add(gxp_watchdog_device);
+ if (ret)
+ platform_device_put(gxp_watchdog_device);
+
+ return ret;
+}
+
+static const struct of_device_id gxp_timer_of_match[] = {
+ { .compatible = "hpe,gxp-timer", },
+ {},
+};
+
+static struct platform_driver gxp_timer_driver = {
+ .probe = gxp_timer_probe,
+ .driver = {
+ .name = "gxp-timer",
+ .of_match_table = gxp_timer_of_match,
+ .suppress_bind_attrs = true,
+ },
+};
+
+builtin_platform_driver(gxp_timer_driver);
+
+TIMER_OF_DECLARE(gxp, "hpe,gxp-timer", gxp_timer_init);