+++ /dev/null
-/*
- * arch/sh/kernel/timers/timer-mtu2.c - MTU2 Timer Support
- *
- * Copyright (C) 2005 Paul Mundt
- *
- * Based off of arch/sh/kernel/timers/timer-tmu.c
- *
- * 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/kernel.h>
-#include <linux/interrupt.h>
-#include <linux/seqlock.h>
-#include <asm/timer.h>
-#include <asm/io.h>
-#include <asm/irq.h>
-#include <asm/clock.h>
-
-/*
- * We use channel 1 for our lowly system timer. Channel 2 would be the other
- * likely candidate, but we leave it alone as it has higher divisors that
- * would be of more use to other more interesting applications.
- *
- * TODO: Presently we only implement a 16-bit single-channel system timer.
- * However, we can implement channel cascade if we go the overflow route and
- * get away with using 2 MTU2 channels as a 32-bit timer.
- */
-#define MTU2_TSTR 0xfffe4280
-#define MTU2_TCR_1 0xfffe4380
-#define MTU2_TMDR_1 0xfffe4381
-#define MTU2_TIOR_1 0xfffe4382
-#define MTU2_TIER_1 0xfffe4384
-#define MTU2_TSR_1 0xfffe4385
-#define MTU2_TCNT_1 0xfffe4386 /* 16-bit counter */
-
-#if defined(CONFIG_CPU_SUBTYPE_SH7201) || \
- defined(CONFIG_CPU_SUBTYPE_SH7203)
-#define MTU2_TGRA_1 0xfffe4388
-#else
-#define MTU2_TGRA_1 0xfffe438a
-#endif
-
-#define STBCR3 0xfffe0408
-
-#define MTU2_TSTR_CST1 (1 << 1) /* Counter Start 1 */
-
-#define MTU2_TSR_TGFA (1 << 0) /* GRA compare match */
-
-#define MTU2_TIER_TGIEA (1 << 0) /* GRA compare match interrupt enable */
-
-#define MTU2_TCR_INIT 0x22
-
-#define MTU2_TCR_CALIB 0x00
-
-static unsigned long mtu2_timer_get_offset(void)
-{
- int count;
- static int count_p = 0x7fff; /* for the first call after boot */
- static unsigned long jiffies_p = 0;
-
- /*
- * cache volatile jiffies temporarily; we have IRQs turned off.
- */
- unsigned long jiffies_t;
-
- /* timer count may underflow right here */
- count = ctrl_inw(MTU2_TCNT_1); /* read the latched count */
-
- jiffies_t = jiffies;
-
- /*
- * avoiding timer inconsistencies (they are rare, but they happen)...
- * there is one kind of problem that must be avoided here:
- * 1. the timer counter underflows
- */
-
- if (jiffies_t == jiffies_p) {
- if (count > count_p) {
- if (ctrl_inb(MTU2_TSR_1) & MTU2_TSR_TGFA) {
- count -= LATCH;
- } else {
- printk("%s (): hardware timer problem?\n",
- __func__);
- }
- }
- } else
- jiffies_p = jiffies_t;
-
- count_p = count;
-
- count = ((LATCH-1) - count) * TICK_SIZE;
- count = (count + LATCH/2) / LATCH;
-
- return count;
-}
-
-static irqreturn_t mtu2_timer_interrupt(int irq, void *dev_id)
-{
- unsigned long timer_status;
-
- /* Clear TGFA bit */
- timer_status = ctrl_inb(MTU2_TSR_1);
- timer_status &= ~MTU2_TSR_TGFA;
- ctrl_outb(timer_status, MTU2_TSR_1);
-
- /* Do timer tick */
- handle_timer_tick();
-
- return IRQ_HANDLED;
-}
-
-static struct irqaction mtu2_irq = {
- .name = "timer",
- .handler = mtu2_timer_interrupt,
- .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
-};
-
-static unsigned int divisors[] = { 1, 4, 16, 64, 1, 1, 256 };
-
-static void mtu2_clk_init(struct clk *clk)
-{
- u8 idx = MTU2_TCR_INIT & 0x7;
-
- clk->rate = clk->parent->rate / divisors[idx];
- /* Start TCNT counting */
- ctrl_outb(ctrl_inb(MTU2_TSTR) | MTU2_TSTR_CST1, MTU2_TSTR);
-
-}
-
-static void mtu2_clk_recalc(struct clk *clk)
-{
- u8 idx = ctrl_inb(MTU2_TCR_1) & 0x7;
- clk->rate = clk->parent->rate / divisors[idx];
-}
-
-static struct clk_ops mtu2_clk_ops = {
- .init = mtu2_clk_init,
- .recalc = mtu2_clk_recalc,
-};
-
-static struct clk mtu2_clk1 = {
- .name = "mtu2_clk1",
- .ops = &mtu2_clk_ops,
-};
-
-static int mtu2_timer_start(void)
-{
- ctrl_outb(ctrl_inb(MTU2_TSTR) | MTU2_TSTR_CST1, MTU2_TSTR);
- return 0;
-}
-
-static int mtu2_timer_stop(void)
-{
- ctrl_outb(ctrl_inb(MTU2_TSTR) & ~MTU2_TSTR_CST1, MTU2_TSTR);
- return 0;
-}
-
-static int mtu2_timer_init(void)
-{
- unsigned long interval;
-
- setup_irq(CONFIG_SH_TIMER_IRQ, &mtu2_irq);
-
- mtu2_clk1.parent = clk_get(NULL, "module_clk");
-
- ctrl_outb(ctrl_inb(STBCR3) & (~0x20), STBCR3);
-
- /* Normal operation */
- ctrl_outb(0, MTU2_TMDR_1);
- ctrl_outb(MTU2_TCR_INIT, MTU2_TCR_1);
- ctrl_outb(0x01, MTU2_TIOR_1);
-
- /* Enable underflow interrupt */
- ctrl_outb(ctrl_inb(MTU2_TIER_1) | MTU2_TIER_TGIEA, MTU2_TIER_1);
-
- interval = CONFIG_SH_PCLK_FREQ / 16 / HZ;
- printk(KERN_INFO "Interval = %ld\n", interval);
-
- ctrl_outw(interval, MTU2_TGRA_1);
- ctrl_outw(0, MTU2_TCNT_1);
-
- clk_register(&mtu2_clk1);
- clk_enable(&mtu2_clk1);
-
- return 0;
-}
-
-struct sys_timer_ops mtu2_timer_ops = {
- .init = mtu2_timer_init,
- .start = mtu2_timer_start,
- .stop = mtu2_timer_stop,
-#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
- .get_offset = mtu2_timer_get_offset,
-#endif
-};
-
-struct sys_timer mtu2_timer = {
- .name = "mtu2",
- .ops = &mtu2_timer_ops,
-};
projects / linux-beck.git / commitdiff