From: Magnus Damm <[email protected]>
This patch updates the clocksource part of the TMU driver
to make use of the __clocksource_updatefreq_hz() function.
Without this patch the old code uses clocksource_register()
together with a hack that assumes a never changing clock rate
(see clk_enable(), clk_get_rate() and clk_disable()).
The patch uses clocksource_register_hz() with 1 Hz as initial
value, then lets the ->enable() callback update the value
with __clocksource_updatefreq_hz() once the struct clk has
been enabled and the frequency is stable.
Signed-off-by: Magnus Damm <[email protected]>
---
Thanks to John Stultz for the framework changes and the
initial implementation.
Tested on the sh7372 Mackerel board with TMU00 and TMU01.
drivers/clocksource/sh_tmu.c | 19 ++++++++-----------
1 file changed, 8 insertions(+), 11 deletions(-)
--- 0001/drivers/clocksource/sh_tmu.c
+++ work/drivers/clocksource/sh_tmu.c 2011-04-25 15:07:41.000000000 +0900
@@ -199,8 +199,12 @@ static cycle_t sh_tmu_clocksource_read(s
static int sh_tmu_clocksource_enable(struct clocksource *cs)
{
struct sh_tmu_priv *p = cs_to_sh_tmu(cs);
+ int ret;
- return sh_tmu_enable(p);
+ ret = sh_tmu_enable(p);
+ if (!ret)
+ __clocksource_updatefreq_hz(cs, p->rate);
+ return ret;
}
static void sh_tmu_clocksource_disable(struct clocksource *cs)
@@ -221,17 +225,10 @@ static int sh_tmu_register_clocksource(s
cs->mask = CLOCKSOURCE_MASK(32);
cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
- /* clk_get_rate() needs an enabled clock */
- clk_enable(p->clk);
- /* channel will be configured at parent clock / 4 */
- p->rate = clk_get_rate(p->clk) / 4;
- clk_disable(p->clk);
- /* TODO: calculate good shift from rate and counter bit width */
- cs->shift = 10;
- cs->mult = clocksource_hz2mult(p->rate, cs->shift);
-
dev_info(&p->pdev->dev, "used as clock source\n");
- clocksource_register(cs);
+
+ /* Register with dummy 1 Hz value, gets updated in ->enable() */
+ clocksource_register_hz(cs, 1);
return 0;
}
On Mon, 2011-04-25 at 22:38 +0900, Magnus Damm wrote:
> From: Magnus Damm <[email protected]>
>
> This patch updates the clocksource part of the TMU driver
> to make use of the __clocksource_updatefreq_hz() function.
>
> Without this patch the old code uses clocksource_register()
> together with a hack that assumes a never changing clock rate
> (see clk_enable(), clk_get_rate() and clk_disable()).
>
> The patch uses clocksource_register_hz() with 1 Hz as initial
> value, then lets the ->enable() callback update the value
> with __clocksource_updatefreq_hz() once the struct clk has
> been enabled and the frequency is stable.
>
> Signed-off-by: Magnus Damm <[email protected]>
Acked-by: John Stultz <[email protected]>
If these don't get picked up for 2.6.40, I'll queue them myself.
thanks
-john
On Thu, Apr 28, 2011 at 01:55:43PM -0700, john stultz wrote:
> On Mon, 2011-04-25 at 22:38 +0900, Magnus Damm wrote:
> > From: Magnus Damm <[email protected]>
> >
> > This patch updates the clocksource part of the TMU driver
> > to make use of the __clocksource_updatefreq_hz() function.
> >
> > Without this patch the old code uses clocksource_register()
> > together with a hack that assumes a never changing clock rate
> > (see clk_enable(), clk_get_rate() and clk_disable()).
> >
> > The patch uses clocksource_register_hz() with 1 Hz as initial
> > value, then lets the ->enable() callback update the value
> > with __clocksource_updatefreq_hz() once the struct clk has
> > been enabled and the frequency is stable.
> >
> > Signed-off-by: Magnus Damm <[email protected]>
>
> Acked-by: John Stultz <[email protected]>
>
> If these don't get picked up for 2.6.40, I'll queue them myself.
>
I've queued them all now, with your Acks, thanks.