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ARM: u300: fix timekeeping when periodic mode is used 

To determine the value to write to the hardware's timer counter register
the symbol CLOCK_TICK_RATE is used. This value is a dummy value on u300
though. So instead use the clock rate that is used for oneshot mode.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
hifive-unleashed-5.1
Uwe Kleine-König 2013-11-05 10:03:19 +01:00 committed by Linus Walleij
parent 8ddd0f6fa6
commit 6a79799d56
1 changed files with 24 additions and 14 deletions
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38
arch/arm/mach-u300/timer.c
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@ -184,11 +184,13 @@
#define U300_TIMER_APP_CRC (0x100)
#define U300_TIMER_APP_CRC_CLOCK_REQUEST_ENABLE (0x00000001)
#define TICKS_PER_JIFFY ((CLOCK_TICK_RATE + (HZ/2)) / HZ)
#define US_PER_TICK ((1000000 + (HZ/2)) / HZ)
static void __iomem *u300_timer_base;
struct u300_clockevent_data {
struct clock_event_device cevd;
unsigned ticks_per_jiffy;
};
/*
* The u300_set_mode() function is always called first, if we
* have oneshot timer active, the oneshot scheduling function
@ -197,6 +199,9 @@ static void __iomem *u300_timer_base;
static void u300_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
struct u300_clockevent_data *cevdata =
container_of(evt, struct u300_clockevent_data, cevd);
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
/* Disable interrupts on GPT1 */
@ -209,7 +214,7 @@ static void u300_set_mode(enum clock_event_mode mode,
* Set the periodic mode to a certain number of ticks per
* jiffy.
*/
writel(TICKS_PER_JIFFY,
writel(cevdata->ticks_per_jiffy,
u300_timer_base + U300_TIMER_APP_GPT1TC);
/*
* Set continuous mode, so the timer keeps triggering
@ -305,20 +310,23 @@ static int u300_set_next_event(unsigned long cycles,
return 0;
}
/* Use general purpose timer 1 as clock event */
static struct clock_event_device clockevent_u300_1mhz = {
.name = "GPT1",
.rating = 300, /* Reasonably fast and accurate clock event */
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
.set_next_event = u300_set_next_event,
.set_mode = u300_set_mode,
static struct u300_clockevent_data u300_clockevent_data = {
/* Use general purpose timer 1 as clock event */
.cevd = {
.name = "GPT1",
/* Reasonably fast and accurate clock event */
.rating = 300,
.features = CLOCK_EVT_FEAT_PERIODIC |
CLOCK_EVT_FEAT_ONESHOT,
.set_next_event = u300_set_next_event,
.set_mode = u300_set_mode,
},
};
/* Clock event timer interrupt handler */
static irqreturn_t u300_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = &clockevent_u300_1mhz;
struct clock_event_device *evt = &u300_clockevent_data.cevd;
/* ACK/Clear timer IRQ for the APP GPT1 Timer */
writel(U300_TIMER_APP_GPT1IA_IRQ_ACK,
@ -379,6 +387,8 @@ static void __init u300_timer_init_of(struct device_node *np)
clk_prepare_enable(clk);
rate = clk_get_rate(clk);
u300_clockevent_data.ticks_per_jiffy = DIV_ROUND_CLOSEST(rate, HZ);
setup_sched_clock(u300_read_sched_clock, 32, rate);
u300_delay_timer.read_current_timer = &u300_read_current_timer;
@ -428,7 +438,7 @@ static void __init u300_timer_init_of(struct device_node *np)
pr_err("timer: failed to initialize U300 clock source\n");
/* Configure and register the clockevent */
clockevents_config_and_register(&clockevent_u300_1mhz, rate,
clockevents_config_and_register(&u300_clockevent_data.cevd, rate,
1, 0xffffffff);
/*