> -----Original Message-----
> From: Hilman, Kevin
> Sent: Tuesday, February 15, 2011 10:45 PM
> To: DebBarma, Tarun Kanti
> Cc: [email protected]; Basak, Partha
> Subject: Re: [PATCH v9 10/11] OMAP: dmtimer: pm_runtime support
>
> Tarun Kanti DebBarma <[email protected]> writes:
>
> > Add pm_runtime support to dmtimer. Since dmtimer is used during
> > early boot before pm_runtime is initialized completely there are
> > provisions to enable/disable clocks directly in the code during
> > early boot.
> >
> > Signed-off-by: Tarun Kanti DebBarma <[email protected]>
> > [[email protected]: added pm_runtime logic in probe()]
> > Signed-off-by: Partha Basak <[email protected]>
> > Reviewed-by: Varadarajan, Charulatha <[email protected]>
> > Acked-by: Cousson, Benoit <[email protected]>
> > ---
> > arch/arm/plat-omap/dmtimer.c | 60
> +++++++++++++++++++++++++++++++++++------
> > 1 files changed, 51 insertions(+), 9 deletions(-)
> >
> > diff --git a/arch/arm/plat-omap/dmtimer.c b/arch/arm/plat-omap/dmtimer.c
> > index ed4aada..4de473b 100644
> > --- a/arch/arm/plat-omap/dmtimer.c
> > +++ b/arch/arm/plat-omap/dmtimer.c
> > @@ -39,6 +39,7 @@
> > #include <linux/delay.h>
> > #include <linux/io.h>
> > #include <linux/slab.h>
> > +#include <linux/pm_runtime.h>
> > #include <linux/err.h>
> > #include <linux/platform_device.h>
> > #include <plat/dmtimer.h>
> > @@ -211,13 +212,16 @@ static void omap_dm_timer_prepare(struct
> omap_dm_timer *timer)
> > {
> > struct dmtimer_platform_data *pdata = timer->pdev->dev.platform_data;
> >
> > - timer->fclk = clk_get(&timer->pdev->dev, "fck");
> > - if (WARN_ON_ONCE(IS_ERR_OR_NULL(timer->fclk))) {
> > - dev_err(&timer->pdev->dev, ": No fclk handle.\n");
> > - return;
> > + if (!pdata->is_omap16xx) {
> > + timer->fclk = clk_get(&timer->pdev->dev, "fck");
> > + if (WARN_ON_ONCE(IS_ERR_OR_NULL(timer->fclk))) {
> > + dev_err(&timer->pdev->dev, ": No fclk handle.\n");
> > + return;
> > + }
> > }
> >
> > - omap_dm_timer_enable(timer);
> > + if (!pdata->is_omap16xx)
> > + omap_dm_timer_enable(timer);
> >
> > if (pdata->dm_timer_reset)
> > pdata->dm_timer_reset(timer);
> > @@ -289,10 +293,22 @@ EXPORT_SYMBOL_GPL(omap_dm_timer_free);
> >
> > void omap_dm_timer_enable(struct omap_dm_timer *timer)
> > {
> > + struct dmtimer_platform_data *pdata = timer->pdev->dev.platform_data;
> > +
> > if (timer->enabled)
> > return;
> >
> > - clk_enable(timer->fclk);
> > + if (unlikely(pdata->is_early_init)) {
> > + clk_enable(timer->fclk);
> > + timer->enabled = 1;
> > + return;
> > + }
> > +
> > + if (pm_runtime_get_sync(&timer->pdev->dev) < 0) {
> > + dev_err(&timer->pdev->dev, "%s: pm_runtime_get_sync() FAILED\n",
> > + __func__);
> > + return;
> > + }
> >
> > timer->enabled = 1;
> > }
> > @@ -300,10 +316,22 @@ EXPORT_SYMBOL_GPL(omap_dm_timer_enable);
> >
> > void omap_dm_timer_disable(struct omap_dm_timer *timer)
> > {
> > + struct dmtimer_platform_data *pdata = timer->pdev->dev.platform_data;
> > +
> > if (!timer->enabled)
> > return;
> >
> > - clk_disable(timer->fclk);
> > + if (unlikely(pdata->is_early_init)) {
> > + clk_disable(timer->fclk);
> > + timer->enabled = 0;
> > + return;
> > + }
> > +
> > + if (pm_runtime_put_sync(&timer->pdev->dev) < 0) {
> > + dev_err(&timer->pdev->dev, "%s: pm_runtime_put_sync() FAILED\n",
> > + __func__);
> > + return;
> > + }
> >
> > timer->enabled = 0;
> > }
> > @@ -422,10 +450,12 @@ int omap_dm_timer_set_source(struct omap_dm_timer
> *timer, int source)
> > if (source < 0 || source >= 3)
> > return -EINVAL;
> >
> > - omap_dm_timer_disable(timer);
> > + if (!pdata->is_omap16xx)
> > + omap_dm_timer_disable(timer);
> > /* change the timer clock source */
> > ret = pdata->set_timer_src(timer->pdev, source);
> > - omap_dm_timer_enable(timer);
> > + if (!pdata->is_omap16xx)
> > + omap_dm_timer_enable(timer);
> >
> > /*
> > * When the functional clock disappears, too quick writes seem
> > @@ -597,11 +627,21 @@ static int __devinit omap_dm_timer_probe(struct
> platform_device *pdev)
> > return -ENODEV;
> > }
> >
> > + /* OMAP2+
>
> please fix multi-line comment style
OK, thanks.
>
> > + * Early timers are already registered and in list.
> > + * What we need to do during second phase of probe
> > + * is to assign the newly allocated/configured pdev
> > + * to timer->pdev. We also call pm_runtime_enable()
> > + * for each device because it could not be called
> > + * during early boot because pm_runtime framework
> > + * was not yet up and running.
> > + */
> > spin_lock_irqsave(&dm_timer_lock, flags);
> > list_for_each_entry(timer, &omap_timer_list, node)
> > if (!pdata->is_early_init && timer->id == pdev->id) {
> > timer->pdev = pdev;
> > spin_unlock_irqrestore(&dm_timer_lock, flags);
> > + pm_runtime_enable(&pdev->dev);
> > dev_dbg(&pdev->dev, "Regular Probed\n");
> > return 0;
> > }
>
> > @@ -652,6 +692,8 @@ static int __devinit omap_dm_timer_probe(struct
> platform_device *pdev)
> > pdata->dm_timer_read_reg = omap_dm_timer_read_reg;
> > pdata->dm_timer_write_reg = omap_dm_timer_write_reg;
> > pdata->is_early_init = 0;
> > + pm_runtime_enable(&pdev->dev);
> > + dev_dbg(&pdev->dev, " pm_runtime enabled\n");
This will be removed since PM runtime is not applicable on OMAP1.
> > }
> >
> > timer->id = pdev->id;
>
> Somehow, you need to also update runtime PM for early timers that were
> enabled. For the PM runtime userspace info to be correct, I think you
> also need to do a 'get' here if the timer has also been enabled.
Yes, I have done in the second pass of probe for timers which are used.
>
> Otherwise, upon boot, checking runtime PM sysfs it looks like no timers
> are active, or ever have been active:
Here is the result after change.
/ # cat /sys/devices/platform/omap/omap_timer.*/power/runtime_status
active
suspended
suspended
suspended
suspended
suspended
suspended
suspended
suspended
suspended
suspended
/ #
# cat /sys/devices/platform/omap/omap_timer.*/power/runtime_active_time
45187
0
0
0
0
0
0
0
0
0
0
--
Tarun
>
>
> / # cat /sys/devices/platform/omap/omap_timer.*/power/runtime_status
> suspended
> suspended
> suspended
> suspended
> suspended
> suspended
> suspended
> suspended
> suspended
> suspended
> suspended
> suspended
> / # cat /sys/devices/platform/omap/omap_timer.*/power/runtime_active_time
> 0
> 0
> 0
> 0
> 0
> 0
> 0
> 0
> 0
> 0
> 0
> 0
> / #
>
> Kevin
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