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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-tegra.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-tegra.c')
-rw-r--r--drivers/clocksource/timer-tegra.c415
1 files changed, 415 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-tegra.c b/drivers/clocksource/timer-tegra.c
new file mode 100644
index 000000000..35b6ce9de
--- /dev/null
+++ b/drivers/clocksource/timer-tegra.c
@@ -0,0 +1,415 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2010 Google, Inc.
+ *
+ * Author:
+ * Colin Cross <ccross@google.com>
+ */
+
+#define pr_fmt(fmt) "tegra-timer: " fmt
+
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/cpu.h>
+#include <linux/cpumask.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/percpu.h>
+#include <linux/sched_clock.h>
+#include <linux/time.h>
+
+#include "timer-of.h"
+
+#define RTC_SECONDS 0x08
+#define RTC_SHADOW_SECONDS 0x0c
+#define RTC_MILLISECONDS 0x10
+
+#define TIMERUS_CNTR_1US 0x10
+#define TIMERUS_USEC_CFG 0x14
+#define TIMERUS_CNTR_FREEZE 0x4c
+
+#define TIMER_PTV 0x0
+#define TIMER_PTV_EN BIT(31)
+#define TIMER_PTV_PER BIT(30)
+#define TIMER_PCR 0x4
+#define TIMER_PCR_INTR_CLR BIT(30)
+
+#define TIMER1_BASE 0x00
+#define TIMER2_BASE 0x08
+#define TIMER3_BASE 0x50
+#define TIMER4_BASE 0x58
+#define TIMER10_BASE 0x90
+
+#define TIMER1_IRQ_IDX 0
+#define TIMER10_IRQ_IDX 10
+
+#define TIMER_1MHz 1000000
+
+static u32 usec_config;
+static void __iomem *timer_reg_base;
+
+static int tegra_timer_set_next_event(unsigned long cycles,
+ struct clock_event_device *evt)
+{
+ void __iomem *reg_base = timer_of_base(to_timer_of(evt));
+
+ /*
+ * Tegra's timer uses n+1 scheme for the counter, i.e. timer will
+ * fire after one tick if 0 is loaded.
+ *
+ * The minimum and maximum numbers of oneshot ticks are defined
+ * by clockevents_config_and_register(1, 0x1fffffff + 1) invocation
+ * below in the code. Hence the cycles (ticks) can't be outside of
+ * a range supportable by hardware.
+ */
+ writel_relaxed(TIMER_PTV_EN | (cycles - 1), reg_base + TIMER_PTV);
+
+ return 0;
+}
+
+static int tegra_timer_shutdown(struct clock_event_device *evt)
+{
+ void __iomem *reg_base = timer_of_base(to_timer_of(evt));
+
+ writel_relaxed(0, reg_base + TIMER_PTV);
+
+ return 0;
+}
+
+static int tegra_timer_set_periodic(struct clock_event_device *evt)
+{
+ void __iomem *reg_base = timer_of_base(to_timer_of(evt));
+ unsigned long period = timer_of_period(to_timer_of(evt));
+
+ writel_relaxed(TIMER_PTV_EN | TIMER_PTV_PER | (period - 1),
+ reg_base + TIMER_PTV);
+
+ return 0;
+}
+
+static irqreturn_t tegra_timer_isr(int irq, void *dev_id)
+{
+ struct clock_event_device *evt = dev_id;
+ void __iomem *reg_base = timer_of_base(to_timer_of(evt));
+
+ writel_relaxed(TIMER_PCR_INTR_CLR, reg_base + TIMER_PCR);
+ evt->event_handler(evt);
+
+ return IRQ_HANDLED;
+}
+
+static void tegra_timer_suspend(struct clock_event_device *evt)
+{
+ void __iomem *reg_base = timer_of_base(to_timer_of(evt));
+
+ writel_relaxed(TIMER_PCR_INTR_CLR, reg_base + TIMER_PCR);
+}
+
+static void tegra_timer_resume(struct clock_event_device *evt)
+{
+ writel_relaxed(usec_config, timer_reg_base + TIMERUS_USEC_CFG);
+}
+
+static DEFINE_PER_CPU(struct timer_of, tegra_to) = {
+ .flags = TIMER_OF_CLOCK | TIMER_OF_BASE,
+
+ .clkevt = {
+ .name = "tegra_timer",
+ .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
+ .set_next_event = tegra_timer_set_next_event,
+ .set_state_shutdown = tegra_timer_shutdown,
+ .set_state_periodic = tegra_timer_set_periodic,
+ .set_state_oneshot = tegra_timer_shutdown,
+ .tick_resume = tegra_timer_shutdown,
+ .suspend = tegra_timer_suspend,
+ .resume = tegra_timer_resume,
+ },
+};
+
+static int tegra_timer_setup(unsigned int cpu)
+{
+ struct timer_of *to = per_cpu_ptr(&tegra_to, cpu);
+
+ writel_relaxed(0, timer_of_base(to) + TIMER_PTV);
+ writel_relaxed(TIMER_PCR_INTR_CLR, timer_of_base(to) + TIMER_PCR);
+
+ irq_force_affinity(to->clkevt.irq, cpumask_of(cpu));
+ enable_irq(to->clkevt.irq);
+
+ /*
+ * Tegra's timer uses n+1 scheme for the counter, i.e. timer will
+ * fire after one tick if 0 is loaded and thus minimum number of
+ * ticks is 1. In result both of the clocksource's tick limits are
+ * higher than a minimum and maximum that hardware register can
+ * take by 1, this is then taken into account by set_next_event
+ * callback.
+ */
+ clockevents_config_and_register(&to->clkevt, timer_of_rate(to),
+ 1, /* min */
+ 0x1fffffff + 1); /* max 29 bits + 1 */
+
+ return 0;
+}
+
+static int tegra_timer_stop(unsigned int cpu)
+{
+ struct timer_of *to = per_cpu_ptr(&tegra_to, cpu);
+
+ disable_irq_nosync(to->clkevt.irq);
+
+ return 0;
+}
+
+static u64 notrace tegra_read_sched_clock(void)
+{
+ return readl_relaxed(timer_reg_base + TIMERUS_CNTR_1US);
+}
+
+#ifdef CONFIG_ARM
+static unsigned long tegra_delay_timer_read_counter_long(void)
+{
+ return readl_relaxed(timer_reg_base + TIMERUS_CNTR_1US);
+}
+
+static struct delay_timer tegra_delay_timer = {
+ .read_current_timer = tegra_delay_timer_read_counter_long,
+ .freq = TIMER_1MHz,
+};
+#endif
+
+static struct timer_of suspend_rtc_to = {
+ .flags = TIMER_OF_BASE | TIMER_OF_CLOCK,
+};
+
+/*
+ * tegra_rtc_read - Reads the Tegra RTC registers
+ * Care must be taken that this function is not called while the
+ * tegra_rtc driver could be executing to avoid race conditions
+ * on the RTC shadow register
+ */
+static u64 tegra_rtc_read_ms(struct clocksource *cs)
+{
+ void __iomem *reg_base = timer_of_base(&suspend_rtc_to);
+
+ u32 ms = readl_relaxed(reg_base + RTC_MILLISECONDS);
+ u32 s = readl_relaxed(reg_base + RTC_SHADOW_SECONDS);
+
+ return (u64)s * MSEC_PER_SEC + ms;
+}
+
+static struct clocksource suspend_rtc_clocksource = {
+ .name = "tegra_suspend_timer",
+ .rating = 200,
+ .read = tegra_rtc_read_ms,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_SUSPEND_NONSTOP,
+};
+
+static inline unsigned int tegra_base_for_cpu(int cpu, bool tegra20)
+{
+ if (tegra20) {
+ switch (cpu) {
+ case 0:
+ return TIMER1_BASE;
+ case 1:
+ return TIMER2_BASE;
+ case 2:
+ return TIMER3_BASE;
+ default:
+ return TIMER4_BASE;
+ }
+ }
+
+ return TIMER10_BASE + cpu * 8;
+}
+
+static inline unsigned int tegra_irq_idx_for_cpu(int cpu, bool tegra20)
+{
+ if (tegra20)
+ return TIMER1_IRQ_IDX + cpu;
+
+ return TIMER10_IRQ_IDX + cpu;
+}
+
+static inline unsigned long tegra_rate_for_timer(struct timer_of *to,
+ bool tegra20)
+{
+ /*
+ * TIMER1-9 are fixed to 1MHz, TIMER10-13 are running off the
+ * parent clock.
+ */
+ if (tegra20)
+ return TIMER_1MHz;
+
+ return timer_of_rate(to);
+}
+
+static int __init tegra_init_timer(struct device_node *np, bool tegra20,
+ int rating)
+{
+ struct timer_of *to;
+ int cpu, ret;
+
+ to = this_cpu_ptr(&tegra_to);
+ ret = timer_of_init(np, to);
+ if (ret)
+ goto out;
+
+ timer_reg_base = timer_of_base(to);
+
+ /*
+ * Configure microsecond timers to have 1MHz clock
+ * Config register is 0xqqww, where qq is "dividend", ww is "divisor"
+ * Uses n+1 scheme
+ */
+ switch (timer_of_rate(to)) {
+ case 12000000:
+ usec_config = 0x000b; /* (11+1)/(0+1) */
+ break;
+ case 12800000:
+ usec_config = 0x043f; /* (63+1)/(4+1) */
+ break;
+ case 13000000:
+ usec_config = 0x000c; /* (12+1)/(0+1) */
+ break;
+ case 16800000:
+ usec_config = 0x0453; /* (83+1)/(4+1) */
+ break;
+ case 19200000:
+ usec_config = 0x045f; /* (95+1)/(4+1) */
+ break;
+ case 26000000:
+ usec_config = 0x0019; /* (25+1)/(0+1) */
+ break;
+ case 38400000:
+ usec_config = 0x04bf; /* (191+1)/(4+1) */
+ break;
+ case 48000000:
+ usec_config = 0x002f; /* (47+1)/(0+1) */
+ break;
+ default:
+ ret = -EINVAL;
+ goto out;
+ }
+
+ writel_relaxed(usec_config, timer_reg_base + TIMERUS_USEC_CFG);
+
+ for_each_possible_cpu(cpu) {
+ struct timer_of *cpu_to = per_cpu_ptr(&tegra_to, cpu);
+ unsigned long flags = IRQF_TIMER | IRQF_NOBALANCING;
+ unsigned long rate = tegra_rate_for_timer(to, tegra20);
+ unsigned int base = tegra_base_for_cpu(cpu, tegra20);
+ unsigned int idx = tegra_irq_idx_for_cpu(cpu, tegra20);
+ unsigned int irq = irq_of_parse_and_map(np, idx);
+
+ if (!irq) {
+ pr_err("failed to map irq for cpu%d\n", cpu);
+ ret = -EINVAL;
+ goto out_irq;
+ }
+
+ cpu_to->clkevt.irq = irq;
+ cpu_to->clkevt.rating = rating;
+ cpu_to->clkevt.cpumask = cpumask_of(cpu);
+ cpu_to->of_base.base = timer_reg_base + base;
+ cpu_to->of_clk.period = rate / HZ;
+ cpu_to->of_clk.rate = rate;
+
+ irq_set_status_flags(cpu_to->clkevt.irq, IRQ_NOAUTOEN);
+
+ ret = request_irq(cpu_to->clkevt.irq, tegra_timer_isr, flags,
+ cpu_to->clkevt.name, &cpu_to->clkevt);
+ if (ret) {
+ pr_err("failed to set up irq for cpu%d: %d\n",
+ cpu, ret);
+ irq_dispose_mapping(cpu_to->clkevt.irq);
+ cpu_to->clkevt.irq = 0;
+ goto out_irq;
+ }
+ }
+
+ sched_clock_register(tegra_read_sched_clock, 32, TIMER_1MHz);
+
+ ret = clocksource_mmio_init(timer_reg_base + TIMERUS_CNTR_1US,
+ "timer_us", TIMER_1MHz, 300, 32,
+ clocksource_mmio_readl_up);
+ if (ret)
+ pr_err("failed to register clocksource: %d\n", ret);
+
+#ifdef CONFIG_ARM
+ register_current_timer_delay(&tegra_delay_timer);
+#endif
+
+ ret = cpuhp_setup_state(CPUHP_AP_TEGRA_TIMER_STARTING,
+ "AP_TEGRA_TIMER_STARTING", tegra_timer_setup,
+ tegra_timer_stop);
+ if (ret)
+ pr_err("failed to set up cpu hp state: %d\n", ret);
+
+ return ret;
+
+out_irq:
+ for_each_possible_cpu(cpu) {
+ struct timer_of *cpu_to;
+
+ cpu_to = per_cpu_ptr(&tegra_to, cpu);
+ if (cpu_to->clkevt.irq) {
+ free_irq(cpu_to->clkevt.irq, &cpu_to->clkevt);
+ irq_dispose_mapping(cpu_to->clkevt.irq);
+ }
+ }
+
+ to->of_base.base = timer_reg_base;
+out:
+ timer_of_cleanup(to);
+
+ return ret;
+}
+
+static int __init tegra210_init_timer(struct device_node *np)
+{
+ /*
+ * Arch-timer can't survive across power cycle of CPU core and
+ * after CPUPORESET signal due to a system design shortcoming,
+ * hence tegra-timer is more preferable on Tegra210.
+ */
+ return tegra_init_timer(np, false, 460);
+}
+TIMER_OF_DECLARE(tegra210_timer, "nvidia,tegra210-timer", tegra210_init_timer);
+
+static int __init tegra20_init_timer(struct device_node *np)
+{
+ int rating;
+
+ /*
+ * Tegra20 and Tegra30 have Cortex A9 CPU that has a TWD timer,
+ * that timer runs off the CPU clock and hence is subjected to
+ * a jitter caused by DVFS clock rate changes. Tegra-timer is
+ * more preferable for older Tegra's, while later SoC generations
+ * have arch-timer as a main per-CPU timer and it is not affected
+ * by DVFS changes.
+ */
+ if (of_machine_is_compatible("nvidia,tegra20") ||
+ of_machine_is_compatible("nvidia,tegra30"))
+ rating = 460;
+ else
+ rating = 330;
+
+ return tegra_init_timer(np, true, rating);
+}
+TIMER_OF_DECLARE(tegra20_timer, "nvidia,tegra20-timer", tegra20_init_timer);
+
+static int __init tegra20_init_rtc(struct device_node *np)
+{
+ int ret;
+
+ ret = timer_of_init(np, &suspend_rtc_to);
+ if (ret)
+ return ret;
+
+ return clocksource_register_hz(&suspend_rtc_clocksource, 1000);
+}
+TIMER_OF_DECLARE(tegra20_rtc, "nvidia,tegra20-rtc", tegra20_init_rtc);