| /* |
| * linux/arch/arm/mach-omap2/timer-gp.c |
| * |
| * OMAP2 GP timer support. |
| * |
| * Copyright (C) 2009 Nokia Corporation |
| * |
| * Update to use new clocksource/clockevent layers |
| * Author: Kevin Hilman, MontaVista Software, Inc. <source@mvista.com> |
| * Copyright (C) 2007 MontaVista Software, Inc. |
| * |
| * Original driver: |
| * Copyright (C) 2005 Nokia Corporation |
| * Author: Paul Mundt <paul.mundt@nokia.com> |
| * Juha Yrjölä <juha.yrjola@nokia.com> |
| * OMAP Dual-mode timer framework support by Timo Teras |
| * |
| * Some parts based off of TI's 24xx code: |
| * |
| * Copyright (C) 2004-2009 Texas Instruments, Inc. |
| * |
| * Roughly modelled after the OMAP1 MPU timer code. |
| * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com> |
| * |
| * This file is subject to the terms and conditions of the GNU General Public |
| * License. See the file "COPYING" in the main directory of this archive |
| * for more details. |
| */ |
| #include <linux/init.h> |
| #include <linux/time.h> |
| #include <linux/interrupt.h> |
| #include <linux/err.h> |
| #include <linux/clk.h> |
| #include <linux/delay.h> |
| #include <linux/irq.h> |
| #include <linux/clocksource.h> |
| #include <linux/clockchips.h> |
| |
| #include <asm/mach/time.h> |
| #include <plat/dmtimer.h> |
| #include <asm/localtimer.h> |
| |
| /* MAX_GPTIMER_ID: number of GPTIMERs on the chip */ |
| #define MAX_GPTIMER_ID 12 |
| |
| static struct omap_dm_timer *gptimer; |
| static struct clock_event_device clockevent_gpt; |
| static u8 __initdata gptimer_id = 1; |
| static u8 __initdata inited; |
| struct omap_dm_timer *gptimer_wakeup; |
| |
| static irqreturn_t omap2_gp_timer_interrupt(int irq, void *dev_id) |
| { |
| struct omap_dm_timer *gpt = (struct omap_dm_timer *)dev_id; |
| struct clock_event_device *evt = &clockevent_gpt; |
| |
| omap_dm_timer_write_status(gpt, OMAP_TIMER_INT_OVERFLOW); |
| |
| evt->event_handler(evt); |
| return IRQ_HANDLED; |
| } |
| |
| static struct irqaction omap2_gp_timer_irq = { |
| .name = "gp timer", |
| .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, |
| .handler = omap2_gp_timer_interrupt, |
| }; |
| |
| static int omap2_gp_timer_set_next_event(unsigned long cycles, |
| struct clock_event_device *evt) |
| { |
| omap_dm_timer_set_load_start(gptimer, 0, 0xffffffff - cycles); |
| |
| return 0; |
| } |
| |
| static void omap2_gp_timer_set_mode(enum clock_event_mode mode, |
| struct clock_event_device *evt) |
| { |
| u32 period; |
| |
| omap_dm_timer_stop(gptimer); |
| |
| switch (mode) { |
| case CLOCK_EVT_MODE_PERIODIC: |
| period = clk_get_rate(omap_dm_timer_get_fclk(gptimer)) / HZ; |
| period -= 1; |
| omap_dm_timer_set_load_start(gptimer, 1, 0xffffffff - period); |
| break; |
| case CLOCK_EVT_MODE_ONESHOT: |
| break; |
| case CLOCK_EVT_MODE_UNUSED: |
| case CLOCK_EVT_MODE_SHUTDOWN: |
| case CLOCK_EVT_MODE_RESUME: |
| break; |
| } |
| } |
| |
| static struct clock_event_device clockevent_gpt = { |
| .name = "gp timer", |
| .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, |
| .shift = 32, |
| .set_next_event = omap2_gp_timer_set_next_event, |
| .set_mode = omap2_gp_timer_set_mode, |
| }; |
| |
| /** |
| * omap2_gp_clockevent_set_gptimer - set which GPTIMER is used for clockevents |
| * @id: GPTIMER to use (1..MAX_GPTIMER_ID) |
| * |
| * Define the GPTIMER that the system should use for the tick timer. |
| * Meant to be called from board-*.c files in the event that GPTIMER1, the |
| * default, is unsuitable. Returns -EINVAL on error or 0 on success. |
| */ |
| int __init omap2_gp_clockevent_set_gptimer(u8 id) |
| { |
| if (id < 1 || id > MAX_GPTIMER_ID) |
| return -EINVAL; |
| |
| BUG_ON(inited); |
| |
| gptimer_id = id; |
| |
| return 0; |
| } |
| |
| static void __init omap2_gp_clockevent_init(void) |
| { |
| u32 tick_rate; |
| int src; |
| |
| inited = 1; |
| |
| gptimer = omap_dm_timer_request_specific(gptimer_id); |
| BUG_ON(gptimer == NULL); |
| gptimer_wakeup = gptimer; |
| |
| #if defined(CONFIG_OMAP_32K_TIMER) |
| src = OMAP_TIMER_SRC_32_KHZ; |
| #else |
| src = OMAP_TIMER_SRC_SYS_CLK; |
| WARN(gptimer_id == 12, "WARNING: GPTIMER12 can only use the " |
| "secure 32KiHz clock source\n"); |
| #endif |
| |
| if (gptimer_id != 12) |
| WARN(IS_ERR_VALUE(omap_dm_timer_set_source(gptimer, src)), |
| "timer-gp: omap_dm_timer_set_source() failed\n"); |
| |
| tick_rate = clk_get_rate(omap_dm_timer_get_fclk(gptimer)); |
| |
| pr_info("OMAP clockevent source: GPTIMER%d at %u Hz\n", |
| gptimer_id, tick_rate); |
| |
| omap2_gp_timer_irq.dev_id = (void *)gptimer; |
| setup_irq(omap_dm_timer_get_irq(gptimer), &omap2_gp_timer_irq); |
| omap_dm_timer_set_int_enable(gptimer, OMAP_TIMER_INT_OVERFLOW); |
| |
| clockevent_gpt.mult = div_sc(tick_rate, NSEC_PER_SEC, |
| clockevent_gpt.shift); |
| clockevent_gpt.max_delta_ns = |
| clockevent_delta2ns(0xffffffff, &clockevent_gpt); |
| clockevent_gpt.min_delta_ns = |
| clockevent_delta2ns(3, &clockevent_gpt); |
| /* Timer internal resynch latency. */ |
| |
| clockevent_gpt.cpumask = cpumask_of(0); |
| clockevents_register_device(&clockevent_gpt); |
| } |
| |
| /* Clocksource code */ |
| |
| #ifdef CONFIG_OMAP_32K_TIMER |
| /* |
| * When 32k-timer is enabled, don't use GPTimer for clocksource |
| * instead, just leave default clocksource which uses the 32k |
| * sync counter. See clocksource setup in see plat-omap/common.c. |
| */ |
| |
| static inline void __init omap2_gp_clocksource_init(void) {} |
| #else |
| /* |
| * clocksource |
| */ |
| static struct omap_dm_timer *gpt_clocksource; |
| static cycle_t clocksource_read_cycles(struct clocksource *cs) |
| { |
| return (cycle_t)omap_dm_timer_read_counter(gpt_clocksource); |
| } |
| |
| static struct clocksource clocksource_gpt = { |
| .name = "gp timer", |
| .rating = 300, |
| .read = clocksource_read_cycles, |
| .mask = CLOCKSOURCE_MASK(32), |
| .shift = 24, |
| .flags = CLOCK_SOURCE_IS_CONTINUOUS, |
| }; |
| |
| /* Setup free-running counter for clocksource */ |
| static void __init omap2_gp_clocksource_init(void) |
| { |
| static struct omap_dm_timer *gpt; |
| u32 tick_rate, tick_period; |
| static char err1[] __initdata = KERN_ERR |
| "%s: failed to request dm-timer\n"; |
| static char err2[] __initdata = KERN_ERR |
| "%s: can't register clocksource!\n"; |
| |
| gpt = omap_dm_timer_request(); |
| if (!gpt) |
| printk(err1, clocksource_gpt.name); |
| gpt_clocksource = gpt; |
| |
| omap_dm_timer_set_source(gpt, OMAP_TIMER_SRC_SYS_CLK); |
| tick_rate = clk_get_rate(omap_dm_timer_get_fclk(gpt)); |
| tick_period = (tick_rate / HZ) - 1; |
| |
| omap_dm_timer_set_load_start(gpt, 1, 0); |
| |
| clocksource_gpt.mult = |
| clocksource_khz2mult(tick_rate/1000, clocksource_gpt.shift); |
| if (clocksource_register(&clocksource_gpt)) |
| printk(err2, clocksource_gpt.name); |
| } |
| #endif |
| |
| static void __init omap2_gp_timer_init(void) |
| { |
| #ifdef CONFIG_LOCAL_TIMERS |
| if (cpu_is_omap44xx()) { |
| twd_base = ioremap(OMAP44XX_LOCAL_TWD_BASE, SZ_256); |
| BUG_ON(!twd_base); |
| } |
| #endif |
| omap_dm_timer_init(); |
| |
| omap2_gp_clockevent_init(); |
| omap2_gp_clocksource_init(); |
| } |
| |
| struct sys_timer omap_timer = { |
| .init = omap2_gp_timer_init, |
| }; |