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 <j.beisert@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

3 files changed, 13 insertions, 150 deletions

diff --git a/arch/arm/mach-mx3/Makefile b/arch/arm/mach-mx3/Makefile
index 68f062b70d33..562c75d2e379 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 5addbb7f711c..eba3e0cd4283 100644
--- a/arch/arm/mach-mx3/mx31ads.c
+++ b/arch/arm/mach-mx3/mx31ads.c
@@ -26,6 +26,7 @@
 #include <asm/hardware.h>
 #include <asm/mach-types.h>
 #include <asm/mach/arch.h>
+#include <asm/mach/time.h>
 #include <asm/memory.h>
 #include <asm/mach/map.h>
 #include <asm/arch/common.h>
@@ -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 fb565c98dbfb..000000000000
--- 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 <linux/module.h>
-#include <linux/init.h>
-#include <linux/interrupt.h>
-#include <linux/irq.h>
-#include <asm/hardware.h>
-#include <asm/mach/time.h>
-#include <asm/io.h>
-#include <asm/arch/common.h>
-
-/*!
- * 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,
-};