/* * arch/arm/mach-pnx4008/time.c * * PNX4008 Timers * * Authors: Vitaly Wool, Dmitry Chigirev, Grigory Tolstolytkin <source@mvista.com> * * 2005 (c) MontaVista Software, Inc. This file is licensed under * the terms of the GNU General Public License version 2. This program * is licensed "as is" without any warranty of any kind, whether express * or implied. */ #include <linux/kernel.h> #include <linux/init.h> #include <linux/delay.h> #include <linux/interrupt.h> #include <linux/sched.h> #include <linux/spinlock.h> #include <linux/module.h> #include <linux/kallsyms.h> #include <linux/time.h> #include <linux/timex.h> #include <linux/irq.h> #include <asm/system.h> #include <asm/hardware.h> #include <asm/io.h> #include <asm/leds.h> #include <asm/mach/time.h> #include <asm/errno.h> /*! Note: all timers are UPCOUNTING */ /*! * Returns number of us since last clock interrupt. Note that interrupts * will have been disabled by do_gettimeoffset() */ static unsigned long pnx4008_gettimeoffset(void) { u32 ticks_to_match = __raw_readl(HSTIM_MATCH0) - __raw_readl(HSTIM_COUNTER); u32 elapsed = LATCH - ticks_to_match; return (elapsed * (tick_nsec / 1000)) / LATCH; } /*! * IRQ handler for the timer */ static irqreturn_t pnx4008_timer_interrupt(int irq, void *dev_id) { if (__raw_readl(HSTIM_INT) & MATCH0_INT) { write_seqlock(&xtime_lock); do { timer_tick(); /* * this algorithm takes care of possible delay * for this interrupt handling longer than a normal * timer period */ __raw_writel(__raw_readl(HSTIM_MATCH0) + LATCH, HSTIM_MATCH0); __raw_writel(MATCH0_INT, HSTIM_INT); /* clear interrupt */ /* * The goal is to keep incrementing HSTIM_MATCH0 * register until HSTIM_MATCH0 indicates time after * what HSTIM_COUNTER indicates. */ } while ((signed) (__raw_readl(HSTIM_MATCH0) - __raw_readl(HSTIM_COUNTER)) < 0); write_sequnlock(&xtime_lock); } return IRQ_HANDLED; } static struct irqaction pnx4008_timer_irq = { .name = "PNX4008 Tick Timer", .flags = IRQF_DISABLED | IRQF_TIMER, .handler = pnx4008_timer_interrupt }; /*! * Set up timer and timer interrupt. */ static __init void pnx4008_setup_timer(void) { __raw_writel(RESET_COUNT, MSTIM_CTRL); while (__raw_readl(MSTIM_COUNTER)) ; /* wait for reset to complete. 100% guarantee event */ __raw_writel(0, MSTIM_CTRL); /* stop the timer */ __raw_writel(0, MSTIM_MCTRL); __raw_writel(RESET_COUNT, HSTIM_CTRL); while (__raw_readl(HSTIM_COUNTER)) ; /* wait for reset to complete. 100% guarantee event */ __raw_writel(0, HSTIM_CTRL); __raw_writel(0, HSTIM_MCTRL); __raw_writel(0, HSTIM_CCR); __raw_writel(12, HSTIM_PMATCH); /* scale down to 1 MHZ */ __raw_writel(LATCH, HSTIM_MATCH0); __raw_writel(MR0_INT, HSTIM_MCTRL); setup_irq(HSTIMER_INT, &pnx4008_timer_irq); __raw_writel(COUNT_ENAB | DEBUG_EN, HSTIM_CTRL); /*start timer, stop when JTAG active */ } /* Timer Clock Control in PM register */ #define TIMCLK_CTRL_REG IO_ADDRESS((PNX4008_PWRMAN_BASE + 0xBC)) #define WATCHDOG_CLK_EN 1 #define TIMER_CLK_EN 2 /* HS and MS timers? */ static u32 timclk_ctrl_reg_save; void pnx4008_timer_suspend(void) { timclk_ctrl_reg_save = __raw_readl(TIMCLK_CTRL_REG); __raw_writel(0, TIMCLK_CTRL_REG); /* disable timers */ } void pnx4008_timer_resume(void) { __raw_writel(timclk_ctrl_reg_save, TIMCLK_CTRL_REG); /* enable timers */ } struct sys_timer pnx4008_timer = { .init = pnx4008_setup_timer, .offset = pnx4008_gettimeoffset, .suspend = pnx4008_timer_suspend, .resume = pnx4008_timer_resume, };