[PATCH v2 2/6] clocksource: msc313e: Add support for ssd20xd-based platforms
From: Romain Perier <romain.perier@gmail.com>
Date: 2021-12-12 18:19:30
Also in:
linux-devicetree, lkml
Subsystem:
arm/mstar/sigmastar armv7 soc support, clocksource, clockevent drivers, the rest · Maintainers:
Daniel Palmer, Romain Perier, Daniel Lezcano, Thomas Gleixner, Linus Torvalds
SSD20X family SoCs have an oscillator running at ~432Mhz for timer1 and timer2, while timer0 is running at 12Mhz. There are no ways to reduce or divide these clocks in the clktree. However, SSD20X SoCs provide an internal "timer_divide" register that can act on this input oscillator. This commit adds support for this register, as timer1 and timer2 are used as clockevents these will run at 48Mhz. Signed-off-by: Romain Perier <romain.perier@gmail.com> --- drivers/clocksource/timer-msc313e.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/drivers/clocksource/timer-msc313e.c b/drivers/clocksource/timer-msc313e.c
index 154e73444a0c..54c54ca7c786 100644
--- a/drivers/clocksource/timer-msc313e.c
+++ b/drivers/clocksource/timer-msc313e.c@@ -33,7 +33,9 @@ #define MSC313E_REG_TIMER_MAX_HIGH 0x0c #define MSC313E_REG_COUNTER_LOW 0x10 #define MSC313E_REG_COUNTER_HIGH 0x14 +#define MSC313E_REG_TIMER_DIVIDE 0x18 +#define MSC313E_CLK_DIVIDER 9 #define TIMER_SYNC_TICKS 3 #ifdef CONFIG_ARM
@@ -179,6 +181,12 @@ static int __init msc313e_clkevt_init(struct device_node *np) if (ret) return ret; + if (of_device_is_compatible(np, "sstar,ssd20xd-timer")) { + to->of_clk.rate = clk_get_rate(to->of_clk.clk) / MSC313E_CLK_DIVIDER; + to->of_clk.period = DIV_ROUND_UP(to->of_clk.rate, HZ); + writew(MSC313E_CLK_DIVIDER - 1, timer_of_base(to) + MSC313E_REG_TIMER_DIVIDE); + } + msc313e_clkevt.cpumask = cpu_possible_mask; msc313e_clkevt.irq = to->of_irq.irq; to->clkevt = msc313e_clkevt;
@@ -242,3 +250,4 @@ static int __init msc313e_timer_init(struct device_node *np) } TIMER_OF_DECLARE(msc313, "mstar,msc313e-timer", msc313e_timer_init); +TIMER_OF_DECLARE(ssd20xd, "sstar,ssd20xd-timer", msc313e_timer_init);
--
2.33.0
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