Hi Daniel,
On Wed, Jun 26, 2013 at 11:27:35PM +0200, Daniel Lezcano wrote:
> On 06/26/2013 11:16 PM, Maxime Ripard wrote:
> > The A10 and the A13 has a 64 bits free running counter that we can use
> > as a clocksource and a sched clock, that were both not used yet on these
> > platforms.
> >
> > Signed-off-by: Maxime Ripard <maxime.rip...@free-electrons.com>
> > ---
> > drivers/clocksource/sun4i_timer.c | 27 +++++++++++++++++++++++++++
> > 1 file changed, 27 insertions(+)
> >
> > diff --git a/drivers/clocksource/sun4i_timer.c
> > b/drivers/clocksource/sun4i_timer.c
> > index bdf34d9..1d2eaa0 100644
> > --- a/drivers/clocksource/sun4i_timer.c
> > +++ b/drivers/clocksource/sun4i_timer.c
> > @@ -23,6 +23,8 @@
> > #include <linux/of_address.h>
> > #include <linux/of_irq.h>
> >
> > +#include <asm/sched_clock.h>
> > +
> > #define TIMER_IRQ_EN_REG 0x00
> > #define TIMER_IRQ_EN(val) BIT(val)
> > #define TIMER_IRQ_ST_REG 0x04
> > @@ -34,6 +36,11 @@
> > #define TIMER_CNTVAL_REG(val) (0x10 * val + 0x18)
> >
> > #define TIMER_SCAL 16
> > +#define TIMER_CNT64_CTL_REG 0xa0
> > +#define TIMER_CNT64_CTL_CLR BIT(0)
> > +#define TIMER_CNT64_CTL_RL BIT(1)
> > +#define TIMER_CNT64_LOW_REG 0xa4
> > +#define TIMER_CNT64_HIGH_REG 0xa8
> >
> > static void __iomem *timer_base;
> >
> > @@ -96,6 +103,20 @@ static struct irqaction sun4i_timer_irq = {
> > .dev_id = &sun4i_clockevent,
> > };
> >
> > +static u32 sun4i_timer_sched_read(void)
> > +{
> > + u32 reg = readl(timer_base + TIMER_CNT64_CTL_REG);
> > + writel(reg | TIMER_CNT64_CTL_RL, timer_base + TIMER_CNT64_CTL_REG);
> > + while (readl(timer_base + TIMER_CNT64_CTL_REG) & TIMER_CNT64_CTL_REG);
>
> Isn't a cpu_relax missing here ?Right. The AND is wrong as well, it should be TIMER_CNT64_CTL_RL, not the reg offset. > > > > + writel(TIMER_CNT64_CTL_CLR, timer_base + TIMER_CNT64_CTL_REG); > > + setup_sched_clock(sun4i_timer_sched_read, 32, clk_get_rate(clk)); > > + clocksource_mmio_init(timer_base + TIMER_CNT64_LOW_REG, node->name, > > + clk_get_rate(clk), 300, 32, > > + sun4i_timer_clksrc_read); > > + > > writel(rate / (TIMER_SCAL * HZ), > > DIV_ROUND_CLOSEST(rate, (TIMER_SCAL * HZ)), ? It's actually fixed in a later patch, but yes. Thanks! Maxime -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com
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