Tarun Kanti DebBarma <tarun.ka...@ti.com> 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.
I'm still not crazy about the duplicate logic (both early & normal) in
all the enable/disable functions.
As I've suggested in the past, why not just do a clk_get, clk_enable in
when the early timers are initialized, then do a clk_disable, clk_put()
as soon as the "normal" device is ready and PM runtime is enabled.
That will greatly simplify the code and eliminate the unnecessary checks
for ->is_early_device which will always be false except for in early
boot (when these functions are not likely to be called anyways.)
> Signed-off-by: Tarun Kanti DebBarma <tarun.ka...@ti.com>
> [p-bas...@ti.com: added pm_runtime logic in probe()]
> Signed-off-by: Partha Basak <p-bas...@ti.com>
> Reviewed-by: Varadarajan, Charulatha <ch...@ti.com>
> Acked-by: Cousson, Benoit <b-cous...@ti.com>
> ---
> arch/arm/plat-omap/dmtimer.c | 63
> ++++++++++++++++++++++++++++++++++++------
> 1 files changed, 54 insertions(+), 9 deletions(-)
>
> diff --git a/arch/arm/plat-omap/dmtimer.c b/arch/arm/plat-omap/dmtimer.c
> index 53f5205..fcac422 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) {
Is this 'is_omap16xx' really needed here? If the clk_get fails, set
timer->fclk to NULL, and any other users of fclk should just check the
validity of timer->fclk.
> + 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);
I don't think this if is needed, as runtime PM calls will essentially be
nops on OMAP1 anyways.
> if (pdata->dm_timer_reset)
> pdata->dm_timer_reset(timer);
> @@ -292,10 +296,22 @@ 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;
> }
Taking my above suggestion, this can be simplified to:
void omap_dm_timer_enable(struct omap_dm_timer *timer)
{
pm_runtime_get_sync(&timer->pdev->dev);
}
Note that with runtime PM, the ->enabled flag is no longer needed
either, as you can simply check pm_runtime_suspended(dev) instead.
> @@ -303,10 +319,22 @@ 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;
> }
Likewise, this becomes
void omap_dm_timer_disable(struct omap_dm_timer *timer)
{
pm_runtime_put_sync(&timer->pdev->dev);
}
> @@ -425,10 +453,12 @@ 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)
drop the if
> + 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)
and this one,
and with that, there are no users of is_omap16xx in this patch.
Kevin
> + omap_dm_timer_enable(timer);
>
> /*
> * When the functional clock disappears, too quick writes seem
> @@ -600,11 +630,26 @@ static int __devinit omap_dm_timer_probe(struct
> platform_device *pdev)
> return -ENODEV;
> }
>
> + /*
> + * OMAP2+
> + * 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);
> + /* update PM runtime for active early timers */
> + if (timer->reserved)
> + pm_runtime_get_sync(&pdev->dev);
> +
> dev_dbg(&pdev->dev, "Regular Probed\n");
> return 0;
> }
--
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