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path: root/drivers/clocksource/timer-qcom.c
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-rw-r--r--drivers/clocksource/timer-qcom.c249
1 files changed, 249 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-qcom.c b/drivers/clocksource/timer-qcom.c
new file mode 100644
index 0000000000..b4afe3a675
--- /dev/null
+++ b/drivers/clocksource/timer-qcom.c
@@ -0,0 +1,249 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *
+ * Copyright (C) 2007 Google, Inc.
+ * Copyright (c) 2009-2012,2014, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/cpu.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/sched_clock.h>
+
+#include <asm/delay.h>
+
+#define TIMER_MATCH_VAL 0x0000
+#define TIMER_COUNT_VAL 0x0004
+#define TIMER_ENABLE 0x0008
+#define TIMER_ENABLE_CLR_ON_MATCH_EN BIT(1)
+#define TIMER_ENABLE_EN BIT(0)
+#define TIMER_CLEAR 0x000C
+#define DGT_CLK_CTL 0x10
+#define DGT_CLK_CTL_DIV_4 0x3
+#define TIMER_STS_GPT0_CLR_PEND BIT(10)
+
+#define GPT_HZ 32768
+
+static void __iomem *event_base;
+static void __iomem *sts_base;
+
+static irqreturn_t msm_timer_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *evt = dev_id;
+ /* Stop the timer tick */
+ if (clockevent_state_oneshot(evt)) {
+ u32 ctrl = readl_relaxed(event_base + TIMER_ENABLE);
+ ctrl &= ~TIMER_ENABLE_EN;
+ writel_relaxed(ctrl, event_base + TIMER_ENABLE);
+ }
+ evt->event_handler(evt);
+ return IRQ_HANDLED;
+}
+
+static int msm_timer_set_next_event(unsigned long cycles,
+ struct clock_event_device *evt)
+{
+ u32 ctrl = readl_relaxed(event_base + TIMER_ENABLE);
+
+ ctrl &= ~TIMER_ENABLE_EN;
+ writel_relaxed(ctrl, event_base + TIMER_ENABLE);
+
+ writel_relaxed(ctrl, event_base + TIMER_CLEAR);
+ writel_relaxed(cycles, event_base + TIMER_MATCH_VAL);
+
+ if (sts_base)
+ while (readl_relaxed(sts_base) & TIMER_STS_GPT0_CLR_PEND)
+ cpu_relax();
+
+ writel_relaxed(ctrl | TIMER_ENABLE_EN, event_base + TIMER_ENABLE);
+ return 0;
+}
+
+static int msm_timer_shutdown(struct clock_event_device *evt)
+{
+ u32 ctrl;
+
+ ctrl = readl_relaxed(event_base + TIMER_ENABLE);
+ ctrl &= ~(TIMER_ENABLE_EN | TIMER_ENABLE_CLR_ON_MATCH_EN);
+ writel_relaxed(ctrl, event_base + TIMER_ENABLE);
+ return 0;
+}
+
+static struct clock_event_device __percpu *msm_evt;
+
+static void __iomem *source_base;
+
+static notrace u64 msm_read_timer_count(struct clocksource *cs)
+{
+ return readl_relaxed(source_base + TIMER_COUNT_VAL);
+}
+
+static struct clocksource msm_clocksource = {
+ .name = "dg_timer",
+ .rating = 300,
+ .read = msm_read_timer_count,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static int msm_timer_irq;
+static int msm_timer_has_ppi;
+
+static int msm_local_timer_starting_cpu(unsigned int cpu)
+{
+ struct clock_event_device *evt = per_cpu_ptr(msm_evt, cpu);
+ int err;
+
+ evt->irq = msm_timer_irq;
+ evt->name = "msm_timer";
+ evt->features = CLOCK_EVT_FEAT_ONESHOT;
+ evt->rating = 200;
+ evt->set_state_shutdown = msm_timer_shutdown;
+ evt->set_state_oneshot = msm_timer_shutdown;
+ evt->tick_resume = msm_timer_shutdown;
+ evt->set_next_event = msm_timer_set_next_event;
+ evt->cpumask = cpumask_of(cpu);
+
+ clockevents_config_and_register(evt, GPT_HZ, 4, 0xffffffff);
+
+ if (msm_timer_has_ppi) {
+ enable_percpu_irq(evt->irq, IRQ_TYPE_EDGE_RISING);
+ } else {
+ err = request_irq(evt->irq, msm_timer_interrupt,
+ IRQF_TIMER | IRQF_NOBALANCING |
+ IRQF_TRIGGER_RISING, "gp_timer", evt);
+ if (err)
+ pr_err("request_irq failed\n");
+ }
+
+ return 0;
+}
+
+static int msm_local_timer_dying_cpu(unsigned int cpu)
+{
+ struct clock_event_device *evt = per_cpu_ptr(msm_evt, cpu);
+
+ evt->set_state_shutdown(evt);
+ disable_percpu_irq(evt->irq);
+ return 0;
+}
+
+static u64 notrace msm_sched_clock_read(void)
+{
+ return msm_clocksource.read(&msm_clocksource);
+}
+
+static unsigned long msm_read_current_timer(void)
+{
+ return msm_clocksource.read(&msm_clocksource);
+}
+
+static struct delay_timer msm_delay_timer = {
+ .read_current_timer = msm_read_current_timer,
+};
+
+static int __init msm_timer_init(u32 dgt_hz, int sched_bits, int irq,
+ bool percpu)
+{
+ struct clocksource *cs = &msm_clocksource;
+ int res = 0;
+
+ msm_timer_irq = irq;
+ msm_timer_has_ppi = percpu;
+
+ msm_evt = alloc_percpu(struct clock_event_device);
+ if (!msm_evt) {
+ pr_err("memory allocation failed for clockevents\n");
+ goto err;
+ }
+
+ if (percpu)
+ res = request_percpu_irq(irq, msm_timer_interrupt,
+ "gp_timer", msm_evt);
+
+ if (res) {
+ pr_err("request_percpu_irq failed\n");
+ } else {
+ /* Install and invoke hotplug callbacks */
+ res = cpuhp_setup_state(CPUHP_AP_QCOM_TIMER_STARTING,
+ "clockevents/qcom/timer:starting",
+ msm_local_timer_starting_cpu,
+ msm_local_timer_dying_cpu);
+ if (res) {
+ free_percpu_irq(irq, msm_evt);
+ goto err;
+ }
+ }
+
+err:
+ writel_relaxed(TIMER_ENABLE_EN, source_base + TIMER_ENABLE);
+ res = clocksource_register_hz(cs, dgt_hz);
+ if (res)
+ pr_err("clocksource_register failed\n");
+ sched_clock_register(msm_sched_clock_read, sched_bits, dgt_hz);
+ msm_delay_timer.freq = dgt_hz;
+ register_current_timer_delay(&msm_delay_timer);
+
+ return res;
+}
+
+static int __init msm_dt_timer_init(struct device_node *np)
+{
+ u32 freq;
+ int irq, ret;
+ struct resource res;
+ u32 percpu_offset;
+ void __iomem *base;
+ void __iomem *cpu0_base;
+
+ base = of_iomap(np, 0);
+ if (!base) {
+ pr_err("Failed to map event base\n");
+ return -ENXIO;
+ }
+
+ /* We use GPT0 for the clockevent */
+ irq = irq_of_parse_and_map(np, 1);
+ if (irq <= 0) {
+ pr_err("Can't get irq\n");
+ return -EINVAL;
+ }
+
+ /* We use CPU0's DGT for the clocksource */
+ if (of_property_read_u32(np, "cpu-offset", &percpu_offset))
+ percpu_offset = 0;
+
+ ret = of_address_to_resource(np, 0, &res);
+ if (ret) {
+ pr_err("Failed to parse DGT resource\n");
+ return ret;
+ }
+
+ cpu0_base = ioremap(res.start + percpu_offset, resource_size(&res));
+ if (!cpu0_base) {
+ pr_err("Failed to map source base\n");
+ return -EINVAL;
+ }
+
+ if (of_property_read_u32(np, "clock-frequency", &freq)) {
+ pr_err("Unknown frequency\n");
+ return -EINVAL;
+ }
+
+ event_base = base + 0x4;
+ sts_base = base + 0x88;
+ source_base = cpu0_base + 0x24;
+ freq /= 4;
+ writel_relaxed(DGT_CLK_CTL_DIV_4, source_base + DGT_CLK_CTL);
+
+ return msm_timer_init(freq, 32, irq, !!percpu_offset);
+}
+TIMER_OF_DECLARE(kpss_timer, "qcom,kpss-timer", msm_dt_timer_init);
+TIMER_OF_DECLARE(scss_timer, "qcom,scss-timer", msm_dt_timer_init);