summaryrefslogtreecommitdiff
path: root/arch/arm/mach-at91/at91sam926x_time.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/mach-at91/at91sam926x_time.c')
-rw-r--r--arch/arm/mach-at91/at91sam926x_time.c294
1 files changed, 0 insertions, 294 deletions
diff --git a/arch/arm/mach-at91/at91sam926x_time.c b/arch/arm/mach-at91/at91sam926x_time.c
deleted file mode 100644
index 0a9e2fc8f796..000000000000
--- a/arch/arm/mach-at91/at91sam926x_time.c
+++ /dev/null
@@ -1,294 +0,0 @@
-/*
- * at91sam926x_time.c - Periodic Interval Timer (PIT) for at91sam926x
- *
- * Copyright (C) 2005-2006 M. Amine SAYA, ATMEL Rousset, France
- * Revision 2005 M. Nicolas Diremdjian, ATMEL Rousset, France
- * Converted to ClockSource/ClockEvents by David Brownell.
- *
- * 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.
- */
-#include <linux/interrupt.h>
-#include <linux/irq.h>
-#include <linux/kernel.h>
-#include <linux/clk.h>
-#include <linux/clockchips.h>
-#include <linux/of.h>
-#include <linux/of_address.h>
-#include <linux/of_irq.h>
-
-#include <asm/mach/time.h>
-#include <mach/hardware.h>
-
-#define AT91_PIT_MR 0x00 /* Mode Register */
-#define AT91_PIT_PITIEN (1 << 25) /* Timer Interrupt Enable */
-#define AT91_PIT_PITEN (1 << 24) /* Timer Enabled */
-#define AT91_PIT_PIV (0xfffff) /* Periodic Interval Value */
-
-#define AT91_PIT_SR 0x04 /* Status Register */
-#define AT91_PIT_PITS (1 << 0) /* Timer Status */
-
-#define AT91_PIT_PIVR 0x08 /* Periodic Interval Value Register */
-#define AT91_PIT_PIIR 0x0c /* Periodic Interval Image Register */
-#define AT91_PIT_PICNT (0xfff << 20) /* Interval Counter */
-#define AT91_PIT_CPIV (0xfffff) /* Inverval Value */
-
-#define PIT_CPIV(x) ((x) & AT91_PIT_CPIV)
-#define PIT_PICNT(x) (((x) & AT91_PIT_PICNT) >> 20)
-
-static u32 pit_cycle; /* write-once */
-static u32 pit_cnt; /* access only w/system irq blocked */
-static void __iomem *pit_base_addr __read_mostly;
-static struct clk *mck;
-
-static inline unsigned int pit_read(unsigned int reg_offset)
-{
- return __raw_readl(pit_base_addr + reg_offset);
-}
-
-static inline void pit_write(unsigned int reg_offset, unsigned long value)
-{
- __raw_writel(value, pit_base_addr + reg_offset);
-}
-
-/*
- * Clocksource: just a monotonic counter of MCK/16 cycles.
- * We don't care whether or not PIT irqs are enabled.
- */
-static cycle_t read_pit_clk(struct clocksource *cs)
-{
- unsigned long flags;
- u32 elapsed;
- u32 t;
-
- raw_local_irq_save(flags);
- elapsed = pit_cnt;
- t = pit_read(AT91_PIT_PIIR);
- raw_local_irq_restore(flags);
-
- elapsed += PIT_PICNT(t) * pit_cycle;
- elapsed += PIT_CPIV(t);
- return elapsed;
-}
-
-static struct clocksource pit_clk = {
- .name = "pit",
- .rating = 175,
- .read = read_pit_clk,
- .flags = CLOCK_SOURCE_IS_CONTINUOUS,
-};
-
-
-/*
- * Clockevent device: interrupts every 1/HZ (== pit_cycles * MCK/16)
- */
-static void
-pit_clkevt_mode(enum clock_event_mode mode, struct clock_event_device *dev)
-{
- switch (mode) {
- case CLOCK_EVT_MODE_PERIODIC:
- /* update clocksource counter */
- pit_cnt += pit_cycle * PIT_PICNT(pit_read(AT91_PIT_PIVR));
- pit_write(AT91_PIT_MR, (pit_cycle - 1) | AT91_PIT_PITEN
- | AT91_PIT_PITIEN);
- break;
- case CLOCK_EVT_MODE_ONESHOT:
- BUG();
- /* FALLTHROUGH */
- case CLOCK_EVT_MODE_SHUTDOWN:
- case CLOCK_EVT_MODE_UNUSED:
- /* disable irq, leaving the clocksource active */
- pit_write(AT91_PIT_MR, (pit_cycle - 1) | AT91_PIT_PITEN);
- break;
- case CLOCK_EVT_MODE_RESUME:
- break;
- }
-}
-
-static void at91sam926x_pit_suspend(struct clock_event_device *cedev)
-{
- /* Disable timer */
- pit_write(AT91_PIT_MR, 0);
-}
-
-static void at91sam926x_pit_reset(void)
-{
- /* Disable timer and irqs */
- pit_write(AT91_PIT_MR, 0);
-
- /* Clear any pending interrupts, wait for PIT to stop counting */
- while (PIT_CPIV(pit_read(AT91_PIT_PIVR)) != 0)
- cpu_relax();
-
- /* Start PIT but don't enable IRQ */
- pit_write(AT91_PIT_MR, (pit_cycle - 1) | AT91_PIT_PITEN);
-}
-
-static void at91sam926x_pit_resume(struct clock_event_device *cedev)
-{
- at91sam926x_pit_reset();
-}
-
-static struct clock_event_device pit_clkevt = {
- .name = "pit",
- .features = CLOCK_EVT_FEAT_PERIODIC,
- .shift = 32,
- .rating = 100,
- .set_mode = pit_clkevt_mode,
- .suspend = at91sam926x_pit_suspend,
- .resume = at91sam926x_pit_resume,
-};
-
-
-/*
- * IRQ handler for the timer.
- */
-static irqreturn_t at91sam926x_pit_interrupt(int irq, void *dev_id)
-{
- /*
- * irqs should be disabled here, but as the irq is shared they are only
- * guaranteed to be off if the timer irq is registered first.
- */
- WARN_ON_ONCE(!irqs_disabled());
-
- /* The PIT interrupt may be disabled, and is shared */
- if ((pit_clkevt.mode == CLOCK_EVT_MODE_PERIODIC)
- && (pit_read(AT91_PIT_SR) & AT91_PIT_PITS)) {
- unsigned nr_ticks;
-
- /* Get number of ticks performed before irq, and ack it */
- nr_ticks = PIT_PICNT(pit_read(AT91_PIT_PIVR));
- do {
- pit_cnt += pit_cycle;
- pit_clkevt.event_handler(&pit_clkevt);
- nr_ticks--;
- } while (nr_ticks);
-
- return IRQ_HANDLED;
- }
-
- return IRQ_NONE;
-}
-
-static struct irqaction at91sam926x_pit_irq = {
- .name = "at91_tick",
- .flags = IRQF_SHARED | IRQF_TIMER | IRQF_IRQPOLL,
- .handler = at91sam926x_pit_interrupt,
- .irq = NR_IRQS_LEGACY + AT91_ID_SYS,
-};
-
-#ifdef CONFIG_OF
-static struct of_device_id pit_timer_ids[] = {
- { .compatible = "atmel,at91sam9260-pit" },
- { /* sentinel */ }
-};
-
-static int __init of_at91sam926x_pit_init(void)
-{
- struct device_node *np;
- int ret;
-
- np = of_find_matching_node(NULL, pit_timer_ids);
- if (!np)
- goto err;
-
- pit_base_addr = of_iomap(np, 0);
- if (!pit_base_addr)
- goto node_err;
-
- mck = of_clk_get(np, 0);
-
- /* Get the interrupts property */
- ret = irq_of_parse_and_map(np, 0);
- if (!ret) {
- pr_crit("AT91: PIT: Unable to get IRQ from DT\n");
- if (!IS_ERR(mck))
- clk_put(mck);
- goto ioremap_err;
- }
- at91sam926x_pit_irq.irq = ret;
-
- of_node_put(np);
-
- return 0;
-
-ioremap_err:
- iounmap(pit_base_addr);
-node_err:
- of_node_put(np);
-err:
- return -EINVAL;
-}
-#else
-static int __init of_at91sam926x_pit_init(void)
-{
- return -EINVAL;
-}
-#endif
-
-/*
- * Set up both clocksource and clockevent support.
- */
-void __init at91sam926x_pit_init(void)
-{
- unsigned long pit_rate;
- unsigned bits;
- int ret;
-
- mck = ERR_PTR(-ENOENT);
-
- /* For device tree enabled device: initialize here */
- of_at91sam926x_pit_init();
-
- /*
- * Use our actual MCK to figure out how many MCK/16 ticks per
- * 1/HZ period (instead of a compile-time constant LATCH).
- */
- if (IS_ERR(mck))
- mck = clk_get(NULL, "mck");
-
- if (IS_ERR(mck))
- panic("AT91: PIT: Unable to get mck clk\n");
- pit_rate = clk_get_rate(mck) / 16;
- pit_cycle = (pit_rate + HZ/2) / HZ;
- WARN_ON(((pit_cycle - 1) & ~AT91_PIT_PIV) != 0);
-
- /* Initialize and enable the timer */
- at91sam926x_pit_reset();
-
- /*
- * Register clocksource. The high order bits of PIV are unused,
- * so this isn't a 32-bit counter unless we get clockevent irqs.
- */
- bits = 12 /* PICNT */ + ilog2(pit_cycle) /* PIV */;
- pit_clk.mask = CLOCKSOURCE_MASK(bits);
- clocksource_register_hz(&pit_clk, pit_rate);
-
- /* Set up irq handler */
- ret = setup_irq(at91sam926x_pit_irq.irq, &at91sam926x_pit_irq);
- if (ret)
- pr_crit("AT91: PIT: Unable to setup IRQ\n");
-
- /* Set up and register clockevents */
- pit_clkevt.mult = div_sc(pit_rate, NSEC_PER_SEC, pit_clkevt.shift);
- pit_clkevt.cpumask = cpumask_of(0);
- clockevents_register_device(&pit_clkevt);
-}
-
-void __init at91sam926x_ioremap_pit(u32 addr)
-{
-#if defined(CONFIG_OF)
- struct device_node *np =
- of_find_matching_node(NULL, pit_timer_ids);
-
- if (np) {
- of_node_put(np);
- return;
- }
-#endif
- pit_base_addr = ioremap(addr, 16);
-
- if (!pit_base_addr)
- panic("Impossible to ioremap PIT\n");
-}