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clocksource/drivers/tegra: Rework for compensation of suspend time 

Since the clocksource framework has the support for suspend time
compensation. Re-work the driver to use that, so we can reduce the
duplicate code.

Suggested-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Joseph Lo <josephl@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
This commit is contained in:
Joseph Lo 2019-04-02 11:02:34 +08:00 committed by Daniel Lezcano
parent dfc82faad7
commit 95170f0708
1 changed files with 20 additions and 43 deletions
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63
drivers/clocksource/timer-tegra20.c
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@ -60,9 +60,6 @@
static u32 usec_config;
static void __iomem *timer_reg_base;
#ifdef CONFIG_ARM
static void __iomem *rtc_base;
static struct timespec64 persistent_ts;
static u64 persistent_ms, last_persistent_ms;
static struct delay_timer tegra_delay_timer;
#endif
@ -199,40 +196,30 @@ static unsigned long tegra_delay_timer_read_counter_long(void)
return readl(timer_reg_base + TIMERUS_CNTR_1US);
}
static struct timer_of suspend_rtc_to = {
.flags = TIMER_OF_BASE | TIMER_OF_CLOCK,
};
/*
* tegra_rtc_read - Reads the Tegra RTC registers
* Care must be taken that this funciton is not called while the
* tegra_rtc driver could be executing to avoid race conditions
* on the RTC shadow register
*/
static u64 tegra_rtc_read_ms(void)
static u64 tegra_rtc_read_ms(struct clocksource *cs)
{
u32 ms = readl(rtc_base + RTC_MILLISECONDS);
u32 s = readl(rtc_base + RTC_SHADOW_SECONDS);
u32 ms = readl(timer_of_base(&suspend_rtc_to) + RTC_MILLISECONDS);
u32 s = readl(timer_of_base(&suspend_rtc_to) + RTC_SHADOW_SECONDS);
return (u64)s * MSEC_PER_SEC + ms;
}
/*
* tegra_read_persistent_clock64 - Return time from a persistent clock.
*
* Reads the time from a source which isn't disabled during PM, the
* 32k sync timer. Convert the cycles elapsed since last read into
* nsecs and adds to a monotonically increasing timespec64.
* Care must be taken that this funciton is not called while the
* tegra_rtc driver could be executing to avoid race conditions
* on the RTC shadow register
*/
static void tegra_read_persistent_clock64(struct timespec64 *ts)
{
u64 delta;
last_persistent_ms = persistent_ms;
persistent_ms = tegra_rtc_read_ms();
delta = persistent_ms - last_persistent_ms;
timespec64_add_ns(&persistent_ts, delta * NSEC_PER_MSEC);
*ts = persistent_ts;
}
static struct clocksource suspend_rtc_clocksource = {
.name = "tegra_suspend_timer",
.rating = 200,
.read = tegra_rtc_read_ms,
.mask = CLOCKSOURCE_MASK(32),
.flags = CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_SUSPEND_NONSTOP,
};
#endif
static int tegra_timer_common_init(struct device_node *np, struct timer_of *to)
@ -385,25 +372,15 @@ out:
static int __init tegra20_init_rtc(struct device_node *np)
{
struct clk *clk;
int ret;
rtc_base = of_iomap(np, 0);
if (!rtc_base) {
pr_err("Can't map RTC registers\n");
return -ENXIO;
}
ret = timer_of_init(np, &suspend_rtc_to);
if (ret)
return ret;
/*
* rtc registers are used by read_persistent_clock, keep the rtc clock
* enabled
*/
clk = of_clk_get(np, 0);
if (IS_ERR(clk))
pr_warn("Unable to get rtc-tegra clock\n");
else
clk_prepare_enable(clk);
clocksource_register_hz(&suspend_rtc_clocksource, 1000);
return register_persistent_clock(tegra_read_persistent_clock64);
return 0;
}
TIMER_OF_DECLARE(tegra20_rtc, "nvidia,tegra20-rtc", tegra20_init_rtc);
#endif