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| author | Olof Johansson <olof@lixom.net> | 2014-07-07 02:47:28 +0200 |
|---|---|---|
| committer | Olof Johansson <olof@lixom.net> | 2014-07-07 02:47:28 +0200 |
| commit | b040614c5bf6af6657574299fdf0572d47b53366 (patch) | |
| tree | 0c969ce83d8a76cfaf3ff7b58d963b668eab23d4 /drivers/clocksource | |
| parent | Merge tag 'renesas-r8a7779-multiplatform-for-v3.17' of git://git.kernel.org/p... (diff) | |
| parent | clocksource: tegra: Use us counter as delay timer (diff) | |
| download | linux-b040614c5bf6af6657574299fdf0572d47b53366.tar.xz linux-b040614c5bf6af6657574299fdf0572d47b53366.zip | |
Merge tag 'tegra-for-3.17-delay-timer' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux into next/soc
Merge "ARM: tegra: use us counter as delay timer" from Stephen Warren:
Tegra has a micro-second counter whose rate doesn't vary with cpufreq
changes. Register it so it can be used as the delay timer, so delays
aren't influenced by cpufreq.
* tag 'tegra-for-3.17-delay-timer' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux:
clocksource: tegra: Use us counter as delay timer
ARM: choose highest resolution delay timer
kernel: add calibration_delay_done()
Signed-off-by: Olof Johansson <olof@lixom.net>
Diffstat (limited to 'drivers/clocksource')
| -rw-r--r-- | drivers/clocksource/tegra20_timer.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/clocksource/tegra20_timer.c b/drivers/clocksource/tegra20_timer.c index d1869f02051c..d2616ef16770 100644 --- a/drivers/clocksource/tegra20_timer.c +++ b/drivers/clocksource/tegra20_timer.c @@ -27,6 +27,7 @@ #include <linux/of_address.h> #include <linux/of_irq.h> #include <linux/sched_clock.h> +#include <linux/delay.h> #include <asm/mach/time.h> #include <asm/smp_twd.h> @@ -53,6 +54,8 @@ static void __iomem *rtc_base; static struct timespec persistent_ts; static u64 persistent_ms, last_persistent_ms; +static struct delay_timer tegra_delay_timer; + #define timer_writel(value, reg) \ __raw_writel(value, timer_reg_base + (reg)) #define timer_readl(reg) \ @@ -139,6 +142,11 @@ static void tegra_read_persistent_clock(struct timespec *ts) *ts = *tsp; } +static unsigned long tegra_delay_timer_read_counter_long(void) +{ + return readl(timer_reg_base + TIMERUS_CNTR_1US); +} + static irqreturn_t tegra_timer_interrupt(int irq, void *dev_id) { struct clock_event_device *evt = (struct clock_event_device *)dev_id; @@ -206,6 +214,11 @@ static void __init tegra20_init_timer(struct device_node *np) BUG(); } + tegra_delay_timer.read_current_timer = + tegra_delay_timer_read_counter_long; + tegra_delay_timer.freq = 1000000; + register_current_timer_delay(&tegra_delay_timer); + ret = setup_irq(tegra_timer_irq.irq, &tegra_timer_irq); if (ret) { pr_err("Failed to register timer IRQ: %d\n", ret); |