diff options
| author | Linus Walleij <linus.walleij@linaro.org> | 2020-06-29 01:01:53 +0300 |
|---|---|---|
| committer | Daniel Lezcano <daniel.lezcano@linaro.org> | 2020-07-23 17:57:43 +0300 |
| commit | aaea0b83458cdb3467e27deb7403b4403152dbd6 (patch) | |
| tree | 19857f94f83b67fad70242c754e9dce6eae67961 /drivers/clocksource | |
| parent | ad7794d4dd0c3f03a81a0dbec3e9e3906edb9893 (diff) | |
| download | linux-aaea0b83458cdb3467e27deb7403b4403152dbd6.tar.xz | |
clocksource/drivers/nomadik-mtu: Handle 32kHz clock
It happens on the U8420-sysclk Ux500 PRCMU firmware
variant that the MTU clock is just 32768 Hz, and in this
mode the minimum ticks is 5 rather than two.
I think this is simply so that there is enough time
for the register write to propagate through the
interconnect to the registers.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200628220153.67011-1-linus.walleij@linaro.org
Diffstat (limited to 'drivers/clocksource')
| -rw-r--r-- | drivers/clocksource/nomadik-mtu.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/drivers/clocksource/nomadik-mtu.c b/drivers/clocksource/nomadik-mtu.c index f49a631d8f58..1cf3304652d6 100644 --- a/drivers/clocksource/nomadik-mtu.c +++ b/drivers/clocksource/nomadik-mtu.c @@ -186,6 +186,7 @@ static int __init nmdk_timer_init(void __iomem *base, int irq, { unsigned long rate; int ret; + int min_ticks; mtu_base = base; @@ -194,7 +195,8 @@ static int __init nmdk_timer_init(void __iomem *base, int irq, /* * Tick rate is 2.4MHz for Nomadik and 2.4Mhz, 100MHz or 133 MHz - * for ux500. + * for ux500, and in one specific Ux500 case 32768 Hz. + * * Use a divide-by-16 counter if the tick rate is more than 32MHz. * At 32 MHz, the timer (with 32 bit counter) can be programmed * to wake-up at a max 127s a head in time. Dividing a 2.4 MHz timer @@ -230,7 +232,12 @@ static int __init nmdk_timer_init(void __iomem *base, int irq, pr_err("%s: request_irq() failed\n", "Nomadik Timer Tick"); nmdk_clkevt.cpumask = cpumask_of(0); nmdk_clkevt.irq = irq; - clockevents_config_and_register(&nmdk_clkevt, rate, 2, 0xffffffffU); + if (rate < 100000) + min_ticks = 5; + else + min_ticks = 2; + clockevents_config_and_register(&nmdk_clkevt, rate, min_ticks, + 0xffffffffU); mtu_delay_timer.read_current_timer = &nmdk_timer_read_current_timer; mtu_delay_timer.freq = rate; |