From d0f349fbce2905607e0473d2358f97f48866e52c Mon Sep 17 00:00:00 2001 From: Juergen Beisert Date: Sat, 5 Jul 2008 10:02:50 +0200 Subject: i.MXC family: Adding timer support This patch adds timer support for the i.MX machine family. This code can be used on the following machs: - i.MX1 (tested) - i.MX2 (i.MX21 (to be tested), i.MX27 (tested)) - i.MX3 (i.MX31 (tested)) TODO: It seems impossible to build a kernel for more than one CPU because the timer do not follow the platform device rules. So it does only work if timer 1 can be accessed on all CPUs at the same address. Signed-off-by: Juergen Beisert Signed-off-by: Sascha Hauer --- arch/arm/mach-mx3/Makefile | 2 +- arch/arm/mach-mx3/mx31ads.c | 13 +++- arch/arm/mach-mx3/time.c | 148 -------------------------------------------- 3 files changed, 13 insertions(+), 150 deletions(-) delete mode 100644 arch/arm/mach-mx3/time.c (limited to 'arch/arm/mach-mx3') diff --git a/arch/arm/mach-mx3/Makefile b/arch/arm/mach-mx3/Makefile index 68f062b70d3..562c75d2e37 100644 --- a/arch/arm/mach-mx3/Makefile +++ b/arch/arm/mach-mx3/Makefile @@ -4,5 +4,5 @@ # Object file lists. -obj-y := mm.o time.o clock.o devices.o iomux.o +obj-y := mm.o clock.o devices.o iomux.o obj-$(CONFIG_MACH_MX31ADS) += mx31ads.o diff --git a/arch/arm/mach-mx3/mx31ads.c b/arch/arm/mach-mx3/mx31ads.c index 5addbb7f711..eba3e0cd428 100644 --- a/arch/arm/mach-mx3/mx31ads.c +++ b/arch/arm/mach-mx3/mx31ads.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include #include @@ -127,6 +128,16 @@ static void __init mxc_board_init(void) mxc_init_extuart(); } +static void __init mx31ads_timer_init(void) +{ + mxc_clocks_init(26000000); + mxc_timer_init("ipg_clk.0"); +} + +struct sys_timer mx31ads_timer = { + .init = mx31ads_timer_init, +}; + /* * The following uses standard kernel macros defined in arch.h in order to * initialize __mach_desc_MX31ADS data structure. @@ -139,5 +150,5 @@ MACHINE_START(MX31ADS, "Freescale MX31ADS") .map_io = mx31ads_map_io, .init_irq = mxc_init_irq, .init_machine = mxc_board_init, - .timer = &mxc_timer, + .timer = &mx31ads_timer, MACHINE_END diff --git a/arch/arm/mach-mx3/time.c b/arch/arm/mach-mx3/time.c deleted file mode 100644 index fb565c98dbf..00000000000 --- a/arch/arm/mach-mx3/time.c +++ /dev/null @@ -1,148 +0,0 @@ -/* - * System Timer Interrupt reconfigured to run in free-run mode. - * Author: Vitaly Wool - * Copyright 2004 MontaVista Software Inc. - * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved. - */ - -/* - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - */ - -/*! - * @file time.c - * @brief This file contains OS tick and wdog timer implementations. - * - * This file contains OS tick and wdog timer implementations. - * - * @ingroup Timers - */ - -#include -#include -#include -#include -#include -#include -#include -#include - -/*! - * This is the timer interrupt service routine to do required tasks. - * It also services the WDOG timer at the frequency of twice per WDOG - * timeout value. For example, if the WDOG's timeout value is 4 (2 - * seconds since the WDOG runs at 0.5Hz), it will be serviced once - * every 2/2=1 second. - * - * @param irq GPT interrupt source number (not used) - * @param dev_id this parameter is not used - * @return always returns \b IRQ_HANDLED as defined in - * include/linux/interrupt.h. - */ -static irqreturn_t mxc_timer_interrupt(int irq, void *dev_id) -{ - unsigned int next_match; - - if (__raw_readl(MXC_GPT_GPTSR) & GPTSR_OF1) { - do { - timer_tick(); - next_match = __raw_readl(MXC_GPT_GPTOCR1) + LATCH; - __raw_writel(GPTSR_OF1, MXC_GPT_GPTSR); - __raw_writel(next_match, MXC_GPT_GPTOCR1); - } while ((signed long)(next_match - - __raw_readl(MXC_GPT_GPTCNT)) <= 0); - } - - return IRQ_HANDLED; -} - -/*! - * This function is used to obtain the number of microseconds since the last - * timer interrupt. Note that interrupts is disabled by do_gettimeofday(). - * - * @return the number of microseconds since the last timer interrupt. - */ -static unsigned long mxc_gettimeoffset(void) -{ - unsigned long ticks_to_match, elapsed, usec, tick_usec, i; - - /* Get ticks before next timer match */ - ticks_to_match = - __raw_readl(MXC_GPT_GPTOCR1) - __raw_readl(MXC_GPT_GPTCNT); - - /* We need elapsed ticks since last match */ - elapsed = LATCH - ticks_to_match; - - /* Now convert them to usec */ - /* Insure no overflow when calculating the usec below */ - for (i = 1, tick_usec = tick_nsec / 1000;; i *= 2) { - tick_usec /= i; - if ((0xFFFFFFFF / tick_usec) > elapsed) - break; - } - usec = (unsigned long)(elapsed * tick_usec) / (LATCH / i); - - return usec; -} - -/*! - * The OS tick timer interrupt structure. - */ -static struct irqaction timer_irq = { - .name = "MXC Timer Tick", - .flags = IRQF_DISABLED | IRQF_TIMER, - .handler = mxc_timer_interrupt -}; - -/*! - * This function is used to initialize the GPT to produce an interrupt - * based on HZ. It is called by start_kernel() during system startup. - */ -void __init mxc_init_time(void) -{ - u32 reg, v; - reg = __raw_readl(MXC_GPT_GPTCR); - reg &= ~GPTCR_ENABLE; - __raw_writel(reg, MXC_GPT_GPTCR); - reg |= GPTCR_SWR; - __raw_writel(reg, MXC_GPT_GPTCR); - - while ((__raw_readl(MXC_GPT_GPTCR) & GPTCR_SWR) != 0) - cpu_relax(); - - reg = GPTCR_FRR | GPTCR_CLKSRC_HIGHFREQ; - __raw_writel(reg, MXC_GPT_GPTCR); - - /* TODO: get timer rate from clk driver */ - v = 66500000; - - __raw_writel((v / CLOCK_TICK_RATE) - 1, MXC_GPT_GPTPR); - - if ((v % CLOCK_TICK_RATE) != 0) { - pr_info("\nWARNING: Can't generate CLOCK_TICK_RATE at %d Hz\n", - CLOCK_TICK_RATE); - } - pr_info("Actual CLOCK_TICK_RATE is %d Hz\n", - v / ((__raw_readl(MXC_GPT_GPTPR) & 0xFFF) + 1)); - - reg = __raw_readl(MXC_GPT_GPTCNT); - reg += LATCH; - __raw_writel(reg, MXC_GPT_GPTOCR1); - - setup_irq(MXC_INT_GPT, &timer_irq); - - reg = __raw_readl(MXC_GPT_GPTCR); - reg = - GPTCR_FRR | GPTCR_CLKSRC_HIGHFREQ | GPTCR_STOPEN | GPTCR_DOZEN | - GPTCR_WAITEN | GPTCR_ENMOD | GPTCR_ENABLE; - __raw_writel(reg, MXC_GPT_GPTCR); - - __raw_writel(GPTIR_OF1IE, MXC_GPT_GPTIR); -} - -struct sys_timer mxc_timer = { - .init = mxc_init_time, - .offset = mxc_gettimeoffset, -}; -- cgit v1.2.3