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

> +      * 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");
>       }
>  
>       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.

Otherwise, upon boot, checking runtime PM sysfs it looks like no timers
are active, or ever have been active:


/ # 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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