clocksource: qcom: Move clocksource code out of mach-msm

We intend to share the clocksource code for MSM platforms between legacy
and multiplatform supported qcom SoCs.

Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Kumar Gala <galak@codeaurora.org>

1 files changed, 329 insertions, 0 deletions

diff --git a/drivers/clocksource/qcom-timer.c b/drivers/clocksource/qcom-timer.c
new file mode 100644
index 00000000000..dca829ec859
--- /dev/null
+++ b/drivers/clocksource/qcom-timer.c
@@ -0,0 +1,329 @@
+/*
+ *
+ * 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>
+
+#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 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;
+}
+
+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 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(__this_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);
+}
+
+#ifdef CONFIG_OF
+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);
+#endif
+
+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;
+}
+
+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);
+}