1 files changed, 411 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-tegra20.c b/drivers/clocksource/timer-tegra20.c
new file mode 100644
index 000000000000..fdb3d795a409
--- /dev/null
+++ b/drivers/clocksource/timer-tegra20.c
@@ -0,0 +1,411 @@
+/*
+ * Copyright (C) 2010 Google, Inc.
+ *
+ * Author:
+ *	Colin Cross <ccross@google.com>
+ *
+ * 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/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"
+
+#ifdef CONFIG_ARM
+#include <asm/mach/time.h>
+#endif
+
+#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)
+
+#ifdef CONFIG_ARM
+#define TIMER_CPU0		0x50 /* TIMER3 */
+#else
+#define TIMER_CPU0		0x90 /* TIMER10 */
+#define TIMER10_IRQ_IDX		10
+#define IRQ_IDX_FOR_CPU(cpu)	(TIMER10_IRQ_IDX + cpu)
+#endif
+#define TIMER_BASE_FOR_CPU(cpu) (TIMER_CPU0 + (cpu) * 8)
+
+static u32 usec_config;
+static void __iomem *timer_reg_base;
+#ifdef CONFIG_ARM
+static void __iomem *rtc_base;
+static struct timespec64 persistent_ts;
+static u64 persistent_ms, last_persistent_ms;
+static struct delay_timer tegra_delay_timer;
+#endif
+
+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));
+
+	writel(TIMER_PTV_EN |
+	       ((cycles > 1) ? (cycles - 1) : 0), /* n+1 scheme */
+	       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(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));
+
+	writel(TIMER_PTV_EN | TIMER_PTV_PER |
+	       ((timer_of_rate(to_timer_of(evt)) / HZ) - 1),
+	       reg_base + TIMER_PTV);
+
+	return 0;
+}
+
+static irqreturn_t tegra_timer_isr(int irq, void *dev_id)
+{
+	struct clock_event_device *evt = (struct clock_event_device *)dev_id;
+	void __iomem *reg_base = timer_of_base(to_timer_of(evt));
+
+	writel(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(TIMER_PCR_INTR_CLR, reg_base + TIMER_PCR);
+}
+
+static void tegra_timer_resume(struct clock_event_device *evt)
+{
+	writel(usec_config, timer_reg_base + TIMERUS_USEC_CFG);
+}
+
+#ifdef CONFIG_ARM64
+static DEFINE_PER_CPU(struct timer_of, tegra_to) = {
+	.flags = TIMER_OF_CLOCK | TIMER_OF_BASE,
+
+	.clkevt = {
+		.name = "tegra_timer",
+		.rating = 460,
+		.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);
+
+	irq_force_affinity(to->clkevt.irq, cpumask_of(cpu));
+	enable_irq(to->clkevt.irq);
+
+	clockevents_config_and_register(&to->clkevt, timer_of_rate(to),
+					1, /* min */
+					0x1fffffff); /* 29 bits */
+
+	return 0;
+}
+
+static int tegra_timer_stop(unsigned int cpu)
+{
+	struct timer_of *to = per_cpu_ptr(&tegra_to, cpu);
+
+	to->clkevt.set_state_shutdown(&to->clkevt);
+	disable_irq_nosync(to->clkevt.irq);
+
+	return 0;
+}
+#else /* CONFIG_ARM */
+static struct timer_of tegra_to = {
+	.flags = TIMER_OF_CLOCK | TIMER_OF_BASE | TIMER_OF_IRQ,
+
+	.clkevt = {
+		.name = "tegra_timer",
+		.rating	= 300,
+		.features = CLOCK_EVT_FEAT_ONESHOT |
+			    CLOCK_EVT_FEAT_PERIODIC |
+			    CLOCK_EVT_FEAT_DYNIRQ,
+		.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,
+		.cpumask = cpu_possible_mask,
+	},
+
+	.of_irq = {
+		.index = 2,
+		.flags = IRQF_TIMER | IRQF_TRIGGER_HIGH,
+		.handler = tegra_timer_isr,
+	},
+};
+
+static u64 notrace tegra_read_sched_clock(void)
+{
+	return readl(timer_reg_base + TIMERUS_CNTR_1US);
+}
+
+static unsigned long tegra_delay_timer_read_counter_long(void)
+{
+	return readl(timer_reg_base + TIMERUS_CNTR_1US);
+}
+
+/*
+ * tegra_rtc_read - Reads the Tegra RTC registers
+ * Care must be taken that this funciton 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(void)
+{
+	u32 ms = readl(rtc_base + RTC_MILLISECONDS);
+	u32 s = readl(rtc_base + RTC_SHADOW_SECONDS);
+	return (u64)s * MSEC_PER_SEC + ms;
+}
+
+/*
+ * tegra_read_persistent_clock64 -  Return time from a persistent clock.
+ *
+ * Reads the time from a source which isn't disabled during PM, the
+ * 32k sync timer.  Convert the cycles elapsed since last read into
+ * nsecs and adds to a monotonically increasing timespec64.
+ * Care must be taken that this funciton is not called while the
+ * tegra_rtc driver could be executing to avoid race conditions
+ * on the RTC shadow register
+ */
+static void tegra_read_persistent_clock64(struct timespec64 *ts)
+{
+	u64 delta;
+
+	last_persistent_ms = persistent_ms;
+	persistent_ms = tegra_rtc_read_ms();
+	delta = persistent_ms - last_persistent_ms;
+
+	timespec64_add_ns(&persistent_ts, delta * NSEC_PER_MSEC);
+	*ts = persistent_ts;
+}
+#endif
+
+static int tegra_timer_common_init(struct device_node *np, struct timer_of *to)
+{
+	int ret = 0;
+
+	ret = timer_of_init(np, to);
+	if (ret < 0)
+		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(usec_config, timer_of_base(to) + TIMERUS_USEC_CFG);
+
+out:
+	return ret;
+}
+
+#ifdef CONFIG_ARM64
+static int __init tegra_init_timer(struct device_node *np)
+{
+	int cpu, ret = 0;
+	struct timer_of *to;
+
+	to = this_cpu_ptr(&tegra_to);
+	ret = tegra_timer_common_init(np, to);
+	if (ret < 0)
+		goto out;
+
+	for_each_possible_cpu(cpu) {
+		struct timer_of *cpu_to;
+
+		cpu_to = per_cpu_ptr(&tegra_to, cpu);
+		cpu_to->of_base.base = timer_reg_base + TIMER_BASE_FOR_CPU(cpu);
+		cpu_to->of_clk.rate = timer_of_rate(to);
+		cpu_to->clkevt.cpumask = cpumask_of(cpu);
+		cpu_to->clkevt.irq =
+			irq_of_parse_and_map(np, IRQ_IDX_FOR_CPU(cpu));
+		if (!cpu_to->clkevt.irq) {
+			pr_err("%s: can't map IRQ for CPU%d\n",
+			       __func__, cpu);
+			ret = -EINVAL;
+			goto out;
+		}
+
+		irq_set_status_flags(cpu_to->clkevt.irq, IRQ_NOAUTOEN);
+		ret = request_irq(cpu_to->clkevt.irq, tegra_timer_isr,
+				  IRQF_TIMER | IRQF_NOBALANCING,
+				  cpu_to->clkevt.name, &cpu_to->clkevt);
+		if (ret) {
+			pr_err("%s: cannot setup irq %d for CPU%d\n",
+				__func__, cpu_to->clkevt.irq, cpu);
+			ret = -EINVAL;
+			goto out_irq;
+		}
+	}
+
+	cpuhp_setup_state(CPUHP_AP_TEGRA_TIMER_STARTING,
+			  "AP_TEGRA_TIMER_STARTING", tegra_timer_setup,
+			  tegra_timer_stop);
+
+	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);
+		}
+	}
+out:
+	timer_of_cleanup(to);
+	return ret;
+}
+#else /* CONFIG_ARM */
+static int __init tegra_init_timer(struct device_node *np)
+{
+	int ret = 0;
+
+	ret = tegra_timer_common_init(np, &tegra_to);
+	if (ret < 0)
+		goto out;
+
+	tegra_to.of_base.base = timer_reg_base + TIMER_BASE_FOR_CPU(0);
+	tegra_to.of_clk.rate = 1000000; /* microsecond timer */
+
+	sched_clock_register(tegra_read_sched_clock, 32,
+			     timer_of_rate(&tegra_to));
+	ret = clocksource_mmio_init(timer_reg_base + TIMERUS_CNTR_1US,
+				    "timer_us", timer_of_rate(&tegra_to),
+				    300, 32, clocksource_mmio_readl_up);
+	if (ret) {
+		pr_err("Failed to register clocksource\n");
+		goto out;
+	}
+
+	tegra_delay_timer.read_current_timer =
+			tegra_delay_timer_read_counter_long;
+	tegra_delay_timer.freq = timer_of_rate(&tegra_to);
+	register_current_timer_delay(&tegra_delay_timer);
+
+	clockevents_config_and_register(&tegra_to.clkevt,
+					timer_of_rate(&tegra_to),
+					0x1,
+					0x1fffffff);
+
+	return ret;
+out:
+	timer_of_cleanup(&tegra_to);
+
+	return ret;
+}
+
+static int __init tegra20_init_rtc(struct device_node *np)
+{
+	struct clk *clk;
+
+	rtc_base = of_iomap(np, 0);
+	if (!rtc_base) {
+		pr_err("Can't map RTC registers\n");
+		return -ENXIO;
+	}
+
+	/*
+	 * rtc registers are used by read_persistent_clock, keep the rtc clock
+	 * enabled
+	 */
+	clk = of_clk_get(np, 0);
+	if (IS_ERR(clk))
+		pr_warn("Unable to get rtc-tegra clock\n");
+	else
+		clk_prepare_enable(clk);
+
+	return register_persistent_clock(tegra_read_persistent_clock64);
+}
+TIMER_OF_DECLARE(tegra20_rtc, "nvidia,tegra20-rtc", tegra20_init_rtc);
+#endif
+TIMER_OF_DECLARE(tegra210_timer, "nvidia,tegra210-timer", tegra_init_timer);
+TIMER_OF_DECLARE(tegra20_timer, "nvidia,tegra20-timer", tegra_init_timer);