diff options
Diffstat (limited to 'arch/arm/mach-tegra/timer.c')
| -rw-r--r-- | arch/arm/mach-tegra/timer.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/arch/arm/mach-tegra/timer.c b/arch/arm/mach-tegra/timer.c new file mode 100644 index 00000000000..2f420210d40 --- /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@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, +}; |