[PATCH v3 05/11] [ARM] tegra: Add timer support
Erik Gilling
konkers at android.com
Mon Jun 14 17:10:21 EDT 2010
From: Colin Cross <ccross at android.com>
v2: fixes from Russell King:
- include linux/io.h instead of asm/io.h
fixes from Gary King:
- remove extra (and incorrect) irq definitions
- use timer 3 instead of timer 1 for compatibility with other drivers
- fix typo that disabled oneshot mode
v3:
- Implement sched_clock
- Fix checkpatch issues
fixes from Gary King:
- Fix incorrect cycles calculation
- Fix min_delta_ns assignment
fixes from Linus Walleij:
- use calc_mult_shift() instead of hard coding values
Signed-off-by: Colin Cross <ccross at android.com>
---
arch/arm/mach-tegra/Makefile | 1 +
arch/arm/mach-tegra/timer.c | 187 ++++++++++++++++++++++++++++++++++++++++++
2 files changed, 188 insertions(+), 0 deletions(-)
create mode 100644 arch/arm/mach-tegra/timer.c
diff --git a/arch/arm/mach-tegra/Makefile b/arch/arm/mach-tegra/Makefile
index f339559..01f47fd 100644
--- a/arch/arm/mach-tegra/Makefile
+++ b/arch/arm/mach-tegra/Makefile
@@ -2,6 +2,7 @@ obj-y += common.o
obj-y += io.o
obj-y += irq.o
obj-y += clock.o
+obj-y += timer.o
obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += tegra2_clocks.o
obj-$(CONFIG_SMP) += platsmp.o localtimer.o headsmp.o
obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
diff --git a/arch/arm/mach-tegra/timer.c b/arch/arm/mach-tegra/timer.c
new file mode 100644
index 0000000..2f42021
--- /dev/null
+++ b/arch/arm/mach-tegra/timer.c
@@ -0,0 +1,187 @@
+/*
+ * arch/arch/mach-tegra/timer.c
+ *
+ * Copyright (C) 2010 Google, Inc.
+ *
+ * Author:
+ * Colin Cross <ccross at 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/init.h>
+#include <linux/time.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/cnt32_to_63.h>
+
+#include <asm/mach/time.h>
+#include <asm/mach/time.h>
+#include <asm/localtimer.h>
+
+#include <mach/iomap.h>
+#include <mach/irqs.h>
+
+#include "board.h"
+#include "clock.h"
+
+#define TIMERUS_CNTR_1US 0x10
+#define TIMERUS_USEC_CFG 0x14
+#define TIMERUS_CNTR_FREEZE 0x4c
+
+#define TIMER1_BASE 0x0
+#define TIMER2_BASE 0x8
+#define TIMER3_BASE 0x50
+#define TIMER4_BASE 0x58
+
+#define TIMER_PTV 0x0
+#define TIMER_PCR 0x4
+
+struct tegra_timer;
+
+static void __iomem *timer_reg_base = IO_ADDRESS(TEGRA_TMR1_BASE);
+
+#define timer_writel(value, reg) \
+ __raw_writel(value, (u32)timer_reg_base + (reg))
+#define timer_readl(reg) \
+ __raw_readl((u32)timer_reg_base + (reg))
+
+static int tegra_timer_set_next_event(unsigned long cycles,
+ struct clock_event_device *evt)
+{
+ u32 reg;
+
+ reg = 0x80000000 | ((cycles > 1) ? (cycles-1) : 0);
+ timer_writel(reg, TIMER3_BASE + TIMER_PTV);
+
+ return 0;
+}
+
+static void tegra_timer_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *evt)
+{
+ u32 reg;
+
+ timer_writel(0, TIMER3_BASE + TIMER_PTV);
+
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ reg = 0xC0000000 | ((1000000/HZ)-1);
+ timer_writel(reg, TIMER3_BASE + TIMER_PTV);
+ break;
+ case CLOCK_EVT_MODE_ONESHOT:
+ break;
+ case CLOCK_EVT_MODE_UNUSED:
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ case CLOCK_EVT_MODE_RESUME:
+ break;
+ }
+}
+
+static cycle_t tegra_clocksource_read(struct clocksource *cs)
+{
+ return cnt32_to_63(timer_readl(TIMERUS_CNTR_1US));
+}
+
+static struct clock_event_device tegra_clockevent = {
+ .name = "timer0",
+ .rating = 300,
+ .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
+ .set_next_event = tegra_timer_set_next_event,
+ .set_mode = tegra_timer_set_mode,
+};
+
+static struct clocksource tegra_clocksource = {
+ .name = "timer_us",
+ .rating = 300,
+ .read = tegra_clocksource_read,
+ .mask = 0x7FFFFFFFFFFFFFFFULL,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+unsigned long long sched_clock(void)
+{
+ return clocksource_cyc2ns(tegra_clocksource.read(&tegra_clocksource),
+ tegra_clocksource.mult, tegra_clocksource.shift);
+}
+
+static irqreturn_t tegra_timer_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *evt = (struct clock_event_device *)dev_id;
+ timer_writel(1<<30, TIMER3_BASE + TIMER_PCR);
+ evt->event_handler(evt);
+ return IRQ_HANDLED;
+}
+
+static struct irqaction tegra_timer_irq = {
+ .name = "timer0",
+ .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_TRIGGER_HIGH,
+ .handler = tegra_timer_interrupt,
+ .dev_id = &tegra_clockevent,
+ .irq = INT_TMR3,
+};
+
+static void __init tegra_init_timer(void)
+{
+ unsigned long rate = clk_measure_input_freq();
+ int ret;
+
+#ifdef CONFIG_HAVE_ARM_TWD
+ twd_base = IO_ADDRESS(TEGRA_ARM_PERIF_BASE + 0x600);
+#endif
+
+ switch (rate) {
+ case 12000000:
+ timer_writel(0x000b, TIMERUS_USEC_CFG);
+ break;
+ case 13000000:
+ timer_writel(0x000c, TIMERUS_USEC_CFG);
+ break;
+ case 19200000:
+ timer_writel(0x045f, TIMERUS_USEC_CFG);
+ break;
+ case 26000000:
+ timer_writel(0x0019, TIMERUS_USEC_CFG);
+ break;
+ default:
+ WARN(1, "Unknown clock rate");
+ }
+
+ if (clocksource_register_hz(&tegra_clocksource, 1000000)) {
+ printk(KERN_ERR "Failed to register clocksource\n");
+ BUG();
+ }
+
+ ret = setup_irq(tegra_timer_irq.irq, &tegra_timer_irq);
+ if (ret) {
+ printk(KERN_ERR "Failed to register timer IRQ: %d\n", ret);
+ BUG();
+ }
+
+ clockevents_calc_mult_shift(&tegra_clockevent, 1000000, 5);
+ tegra_clockevent.max_delta_ns =
+ clockevent_delta2ns(0x1fffffff, &tegra_clockevent);
+ tegra_clockevent.min_delta_ns =
+ clockevent_delta2ns(0x1, &tegra_clockevent);
+ tegra_clockevent.cpumask = cpu_all_mask;
+ tegra_clockevent.irq = tegra_timer_irq.irq;
+ clockevents_register_device(&tegra_clockevent);
+
+ return;
+}
+
+struct sys_timer tegra_timer = {
+ .init = tegra_init_timer,
+};
--
1.6.5.6
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