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Diffstat (limited to 'arch/arm/mach-omap1/time.c')
| -rw-r--r-- | arch/arm/mach-omap1/time.c | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/arch/arm/mach-omap1/time.c b/arch/arm/mach-omap1/time.c new file mode 100644 index 000000000..de590a85a --- /dev/null +++ b/arch/arm/mach-omap1/time.c @@ -0,0 +1,229 @@ +/* + * linux/arch/arm/mach-omap1/time.c + * + * OMAP Timers + * + * Copyright (C) 2004 Nokia Corporation + * Partial timer rewrite and additional dynamic tick timer support by + * Tony Lindgen <tony@atomide.com> and + * Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com> + * + * MPU timer code based on the older MPU timer code for OMAP + * Copyright (C) 2000 RidgeRun, Inc. + * Author: Greg Lonnon <glonnon@ridgerun.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + * + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN + * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF + * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON + * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/delay.h> +#include <linux/interrupt.h> +#include <linux/spinlock.h> +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/clocksource.h> +#include <linux/clockchips.h> +#include <linux/io.h> +#include <linux/sched_clock.h> + +#include <asm/irq.h> + +#include <mach/hardware.h> +#include <asm/mach/irq.h> +#include <asm/mach/time.h> + +#include "iomap.h" +#include "common.h" + +#ifdef CONFIG_OMAP_MPU_TIMER + +#define OMAP_MPU_TIMER_BASE OMAP_MPU_TIMER1_BASE +#define OMAP_MPU_TIMER_OFFSET 0x100 + +typedef struct { + u32 cntl; /* CNTL_TIMER, R/W */ + u32 load_tim; /* LOAD_TIM, W */ + u32 read_tim; /* READ_TIM, R */ +} omap_mpu_timer_regs_t; + +#define omap_mpu_timer_base(n) \ +((omap_mpu_timer_regs_t __iomem *)OMAP1_IO_ADDRESS(OMAP_MPU_TIMER_BASE + \ + (n)*OMAP_MPU_TIMER_OFFSET)) + +static inline unsigned long notrace omap_mpu_timer_read(int nr) +{ + omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(nr); + return readl(&timer->read_tim); +} + +static inline void omap_mpu_set_autoreset(int nr) +{ + omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(nr); + + writel(readl(&timer->cntl) | MPU_TIMER_AR, &timer->cntl); +} + +static inline void omap_mpu_remove_autoreset(int nr) +{ + omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(nr); + + writel(readl(&timer->cntl) & ~MPU_TIMER_AR, &timer->cntl); +} + +static inline void omap_mpu_timer_start(int nr, unsigned long load_val, + int autoreset) +{ + omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(nr); + unsigned int timerflags = MPU_TIMER_CLOCK_ENABLE | MPU_TIMER_ST; + + if (autoreset) + timerflags |= MPU_TIMER_AR; + + writel(MPU_TIMER_CLOCK_ENABLE, &timer->cntl); + udelay(1); + writel(load_val, &timer->load_tim); + udelay(1); + writel(timerflags, &timer->cntl); +} + +static inline void omap_mpu_timer_stop(int nr) +{ + omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(nr); + + writel(readl(&timer->cntl) & ~MPU_TIMER_ST, &timer->cntl); +} + +/* + * --------------------------------------------------------------------------- + * MPU timer 1 ... count down to zero, interrupt, reload + * --------------------------------------------------------------------------- + */ +static int omap_mpu_set_next_event(unsigned long cycles, + struct clock_event_device *evt) +{ + omap_mpu_timer_start(0, cycles, 0); + return 0; +} + +static int omap_mpu_set_oneshot(struct clock_event_device *evt) +{ + omap_mpu_timer_stop(0); + omap_mpu_remove_autoreset(0); + return 0; +} + +static int omap_mpu_set_periodic(struct clock_event_device *evt) +{ + omap_mpu_set_autoreset(0); + return 0; +} + +static struct clock_event_device clockevent_mpu_timer1 = { + .name = "mpu_timer1", + .features = CLOCK_EVT_FEAT_PERIODIC | + CLOCK_EVT_FEAT_ONESHOT, + .set_next_event = omap_mpu_set_next_event, + .set_state_periodic = omap_mpu_set_periodic, + .set_state_oneshot = omap_mpu_set_oneshot, +}; + +static irqreturn_t omap_mpu_timer1_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evt = &clockevent_mpu_timer1; + + evt->event_handler(evt); + + return IRQ_HANDLED; +} + +static __init void omap_init_mpu_timer(unsigned long rate) +{ + if (request_irq(INT_TIMER1, omap_mpu_timer1_interrupt, + IRQF_TIMER | IRQF_IRQPOLL, "mpu_timer1", NULL)) + pr_err("Failed to request irq %d (mpu_timer1)\n", INT_TIMER1); + omap_mpu_timer_start(0, (rate / HZ) - 1, 1); + + clockevent_mpu_timer1.cpumask = cpumask_of(0); + clockevents_config_and_register(&clockevent_mpu_timer1, rate, + 1, -1); +} + + +/* + * --------------------------------------------------------------------------- + * MPU timer 2 ... free running 32-bit clock source and scheduler clock + * --------------------------------------------------------------------------- + */ + +static u64 notrace omap_mpu_read_sched_clock(void) +{ + return ~omap_mpu_timer_read(1); +} + +static void __init omap_init_clocksource(unsigned long rate) +{ + omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(1); + static char err[] __initdata = KERN_ERR + "%s: can't register clocksource!\n"; + + omap_mpu_timer_start(1, ~0, 1); + sched_clock_register(omap_mpu_read_sched_clock, 32, rate); + + if (clocksource_mmio_init(&timer->read_tim, "mpu_timer2", rate, + 300, 32, clocksource_mmio_readl_down)) + printk(err, "mpu_timer2"); +} + +static void __init omap_mpu_timer_init(void) +{ + struct clk *ck_ref = clk_get(NULL, "ck_ref"); + unsigned long rate; + + BUG_ON(IS_ERR(ck_ref)); + + rate = clk_get_rate(ck_ref); + clk_put(ck_ref); + + /* PTV = 0 */ + rate /= 2; + + omap_init_mpu_timer(rate); + omap_init_clocksource(rate); +} + +#else +static inline void omap_mpu_timer_init(void) +{ + pr_err("Bogus timer, should not happen\n"); +} +#endif /* CONFIG_OMAP_MPU_TIMER */ + +/* + * --------------------------------------------------------------------------- + * Timer initialization + * --------------------------------------------------------------------------- + */ +void __init omap1_timer_init(void) +{ + if (omap_32k_timer_init() != 0) + omap_mpu_timer_init(); +} |