summaryrefslogtreecommitdiff
path: root/drivers/clocksource/qcom-timer.c
diff options
context:
space:
mode:
authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/clocksource/qcom-timer.c
Initial import
Diffstat (limited to 'drivers/clocksource/qcom-timer.c')
-rw-r--r--drivers/clocksource/qcom-timer.c343
1 files changed, 343 insertions, 0 deletions
diff --git a/drivers/clocksource/qcom-timer.c b/drivers/clocksource/qcom-timer.c
new file mode 100644
index 000000000..098c542e5
--- /dev/null
+++ b/drivers/clocksource/qcom-timer.c
@@ -0,0 +1,343 @@
+/*
+ *
+ * Copyright (C) 2007 Google, Inc.
+ * Copyright (c) 2009-2012,2014, The Linux Foundation. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#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
+
+#define MSM_DGT_SHIFT 5
+
+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 (evt->mode == CLOCK_EVT_MODE_ONESHOT) {
+ 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 void msm_timer_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *evt)
+{
+ u32 ctrl;
+
+ ctrl = readl_relaxed(event_base + TIMER_ENABLE);
+ ctrl &= ~(TIMER_ENABLE_EN | TIMER_ENABLE_CLR_ON_MATCH_EN);
+
+ switch (mode) {
+ case CLOCK_EVT_MODE_RESUME:
+ case CLOCK_EVT_MODE_PERIODIC:
+ break;
+ case CLOCK_EVT_MODE_ONESHOT:
+ /* Timer is enabled in set_next_event */
+ break;
+ case CLOCK_EVT_MODE_UNUSED:
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ break;
+ }
+ writel_relaxed(ctrl, event_base + TIMER_ENABLE);
+}
+
+static struct clock_event_device __percpu *msm_evt;
+
+static void __iomem *source_base;
+
+static notrace cycle_t 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_setup(struct clock_event_device *evt)
+{
+ int cpu = smp_processor_id();
+ int err;
+
+ evt->irq = msm_timer_irq;
+ evt->name = "msm_timer";
+ evt->features = CLOCK_EVT_FEAT_ONESHOT;
+ evt->rating = 200;
+ evt->set_mode = msm_timer_set_mode;
+ 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 void msm_local_timer_stop(struct clock_event_device *evt)
+{
+ evt->set_mode(CLOCK_EVT_MODE_UNUSED, evt);
+ disable_percpu_irq(evt->irq);
+}
+
+static int msm_timer_cpu_notify(struct notifier_block *self,
+ unsigned long action, void *hcpu)
+{
+ /*
+ * Grab cpu pointer in each case to avoid spurious
+ * preemptible warnings
+ */
+ switch (action & ~CPU_TASKS_FROZEN) {
+ case CPU_STARTING:
+ msm_local_timer_setup(this_cpu_ptr(msm_evt));
+ break;
+ case CPU_DYING:
+ msm_local_timer_stop(this_cpu_ptr(msm_evt));
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block msm_timer_cpu_nb = {
+ .notifier_call = msm_timer_cpu_notify,
+};
+
+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 void __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 {
+ res = register_cpu_notifier(&msm_timer_cpu_nb);
+ if (res) {
+ free_percpu_irq(irq, msm_evt);
+ goto err;
+ }
+
+ /* Immediately configure the timer on the boot CPU */
+ msm_local_timer_setup(raw_cpu_ptr(msm_evt));
+ }
+
+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);
+}
+
+#ifdef CONFIG_ARCH_QCOM
+static void __init msm_dt_timer_init(struct device_node *np)
+{
+ u32 freq;
+ int irq;
+ 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;
+ }
+
+ /* 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;
+ }
+
+ /* We use CPU0's DGT for the clocksource */
+ if (of_property_read_u32(np, "cpu-offset", &percpu_offset))
+ percpu_offset = 0;
+
+ if (of_address_to_resource(np, 0, &res)) {
+ pr_err("Failed to parse DGT resource\n");
+ return;
+ }
+
+ cpu0_base = ioremap(res.start + percpu_offset, resource_size(&res));
+ if (!cpu0_base) {
+ pr_err("Failed to map source base\n");
+ return;
+ }
+
+ if (of_property_read_u32(np, "clock-frequency", &freq)) {
+ pr_err("Unknown frequency\n");
+ return;
+ }
+
+ 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);
+
+ msm_timer_init(freq, 32, irq, !!percpu_offset);
+}
+CLOCKSOURCE_OF_DECLARE(kpss_timer, "qcom,kpss-timer", msm_dt_timer_init);
+CLOCKSOURCE_OF_DECLARE(scss_timer, "qcom,scss-timer", msm_dt_timer_init);
+#else
+
+static int __init msm_timer_map(phys_addr_t addr, u32 event, u32 source,
+ u32 sts)
+{
+ void __iomem *base;
+
+ base = ioremap(addr, SZ_256);
+ if (!base) {
+ pr_err("Failed to map timer base\n");
+ return -ENOMEM;
+ }
+ event_base = base + event;
+ source_base = base + source;
+ if (sts)
+ sts_base = base + sts;
+
+ return 0;
+}
+
+static notrace cycle_t msm_read_timer_count_shift(struct clocksource *cs)
+{
+ /*
+ * Shift timer count down by a constant due to unreliable lower bits
+ * on some targets.
+ */
+ return msm_read_timer_count(cs) >> MSM_DGT_SHIFT;
+}
+
+void __init msm7x01_timer_init(void)
+{
+ struct clocksource *cs = &msm_clocksource;
+
+ if (msm_timer_map(0xc0100000, 0x0, 0x10, 0x0))
+ return;
+ cs->read = msm_read_timer_count_shift;
+ cs->mask = CLOCKSOURCE_MASK((32 - MSM_DGT_SHIFT));
+ /* 600 KHz */
+ msm_timer_init(19200000 >> MSM_DGT_SHIFT, 32 - MSM_DGT_SHIFT, 7,
+ false);
+}
+
+void __init msm7x30_timer_init(void)
+{
+ if (msm_timer_map(0xc0100000, 0x4, 0x24, 0x80))
+ return;
+ msm_timer_init(24576000 / 4, 32, 1, false);
+}
+
+void __init qsd8x50_timer_init(void)
+{
+ if (msm_timer_map(0xAC100000, 0x0, 0x10, 0x34))
+ return;
+ msm_timer_init(19200000 / 4, 32, 7, false);
+}
+#endif