diff options
Diffstat (limited to 'arch/arm/mach-at91/at91sam926x_time.c')
| -rw-r--r-- | arch/arm/mach-at91/at91sam926x_time.c | 140 |
1 files changed, 114 insertions, 26 deletions
diff --git a/arch/arm/mach-at91/at91sam926x_time.c b/arch/arm/mach-at91/at91sam926x_time.c index d89ead740a9..0a9e2fc8f79 100644 --- a/arch/arm/mach-at91/at91sam926x_time.c +++ b/arch/arm/mach-at91/at91sam926x_time.c @@ -14,11 +14,25 @@ #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> -#include <mach/at91_pit.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) @@ -26,6 +40,7 @@ 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) { @@ -91,12 +106,38 @@ pit_clkevt_mode(enum clock_event_mode mode, struct clock_event_device *dev) } } +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, }; @@ -132,36 +173,84 @@ static irqreturn_t at91sam926x_pit_interrupt(int irq, void *dev_id) static struct irqaction at91sam926x_pit_irq = { .name = "at91_tick", - .flags = IRQF_SHARED | IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, - .handler = at91sam926x_pit_interrupt + .flags = IRQF_SHARED | IRQF_TIMER | IRQF_IRQPOLL, + .handler = at91sam926x_pit_interrupt, + .irq = NR_IRQS_LEGACY + AT91_ID_SYS, }; -static void at91sam926x_pit_reset(void) +#ifdef CONFIG_OF +static struct of_device_id pit_timer_ids[] = { + { .compatible = "atmel,at91sam9260-pit" }, + { /* sentinel */ } +}; + +static int __init of_at91sam926x_pit_init(void) { - /* Disable timer and irqs */ - pit_write(AT91_PIT_MR, 0); + struct device_node *np; + int ret; - /* Clear any pending interrupts, wait for PIT to stop counting */ - while (PIT_CPIV(pit_read(AT91_PIT_PIVR)) != 0) - cpu_relax(); + np = of_find_matching_node(NULL, pit_timer_ids); + if (!np) + goto err; - /* Start PIT but don't enable IRQ */ - pit_write(AT91_PIT_MR, (pit_cycle - 1) | AT91_PIT_PITEN); + 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. */ -static void __init at91sam926x_pit_init(void) +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). */ - pit_rate = clk_get_rate(clk_get(NULL, "mck")) / 16; + 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); @@ -177,7 +266,9 @@ static void __init at91sam926x_pit_init(void) clocksource_register_hz(&pit_clk, pit_rate); /* Set up irq handler */ - setup_irq(AT91_ID_SYS, &at91sam926x_pit_irq); + 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); @@ -185,22 +276,19 @@ static void __init at91sam926x_pit_init(void) clockevents_register_device(&pit_clkevt); } -static void at91sam926x_pit_suspend(void) -{ - /* Disable timer */ - pit_write(AT91_PIT_MR, 0); -} - 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"); } - -struct sys_timer at91sam926x_timer = { - .init = at91sam926x_pit_init, - .suspend = at91sam926x_pit_suspend, - .resume = at91sam926x_pit_reset, -}; |