[PATCH v3 8/9] pwm: pwm-omap-dmtimer: Adapt driver to utilize dmtimer pdata ops

[grygorii.strashko@ti.com (Grygorii Strashko)]

On 11/30/2017 03:36 AM, Keerthy wrote:
> 
> 
> On Tuesday 28 November 2017 11:57 PM, Strashko, Grygorii wrote:
>>
>>
>> On 11/15/2017 10:23 PM, Keerthy wrote:
>>> Adapt driver to utilize dmtimer pdata ops instead of pdata-quirks.
>>>
>>> Signed-off-by: Keerthy <j-keerthy@ti.com>
>>> ---
>>>
>>> Changes in v3:
>>>
>>>     * Used of_find_platdata_by_node function to fetch platform
>>>       data for timer node.
>>>
>>>    drivers/pwm/pwm-omap-dmtimer.c | 39 ++++++++++++++++++++++-----------------
>>>    1 file changed, 22 insertions(+), 17 deletions(-)
>>>
>>> diff --git a/drivers/pwm/pwm-omap-dmtimer.c b/drivers/pwm/pwm-omap-dmtimer.c
>>> index 5ad42f3..2caf46b 100644
>>> --- a/drivers/pwm/pwm-omap-dmtimer.c
>>> +++ b/drivers/pwm/pwm-omap-dmtimer.c
>>> @@ -23,6 +23,7 @@
>>>    #include <linux/mutex.h>
>>>    #include <linux/of.h>
>>>    #include <linux/of_platform.h>
>>> +#include <linux/platform_data/dmtimer-omap.h>
>>>    #include <linux/platform_data/pwm_omap_dmtimer.h>
>>>    #include <linux/platform_device.h>
>>>    #include <linux/pm_runtime.h>
>>> @@ -37,7 +38,7 @@ struct pwm_omap_dmtimer_chip {
>>>    	struct pwm_chip chip;
>>>    	struct mutex mutex;
>>>    	pwm_omap_dmtimer *dm_timer;
>>> -	struct pwm_omap_dmtimer_pdata *pdata;
>>> +	struct omap_dm_timer_ops *pdata;
>>>    	struct platform_device *dm_timer_pdev;
>>>    };
>>>    
>>> @@ -242,19 +243,33 @@ static int pwm_omap_dmtimer_probe(struct platform_device *pdev)
>>>    {
>>>    	struct device_node *np = pdev->dev.of_node;
>>>    	struct device_node *timer;
>>> +	struct platform_device *timer_pdev;
>>>    	struct pwm_omap_dmtimer_chip *omap;
>>> -	struct pwm_omap_dmtimer_pdata *pdata;
>>> +	struct dmtimer_platform_data *timer_pdata;
>>> +	struct omap_dm_timer_ops *pdata;
>>>    	pwm_omap_dmtimer *dm_timer;
>>>    	u32 v;
>>>    	int status;
>>>    
>>> -	pdata = dev_get_platdata(&pdev->dev);
>>> -	if (!pdata) {
>>> -		dev_err(&pdev->dev, "Missing dmtimer platform data\n");
>>> +	timer = of_parse_phandle(np, "ti,timers", 0);
>>> +	if (!timer)
>>> +		return -ENODEV;
>>> +
>>> +	timer_pdev = of_find_device_by_node(timer);
>>> +	if (!timer_pdev) {
>>> +		dev_err(&pdev->dev, "Unable to find Timer pdev\n");
>>> +		return -ENODEV;
>>> +	}
>>> +
>>> +	timer_pdata = of_find_platdata_by_node(timer);
>>> +	if (!timer_pdata) {
>>> +		dev_err(&pdev->dev, "dmtimer pdata structure NULL\n");
>>>    		return -EINVAL;
>>>    	}
>>
>> Huh. I think It might be better if you add smth. like
>>
>> struct omap_dm_timer *dm_timer = of_omap_dm_timer_get(parent_np, "ti,timers", idx);
>>
>> struct omap_dm_timer_ops *pdata = omap_dm_timer_get_ops(dm_timer);
>>
>> so all DT and platdata implementation details will be hidden.
> 
> Grygorii,
> 
> This driver is already fetching:
> 
> omap->dm_timer_pdev = of_find_device_by_node(timer);
> 
> It stores dm_timer_pdev in struct pwm_omap_dmtimer_chip.
> So we already need:
> timer = of_parse_phandle(np, "ti,timers", 0);
> and
> omap->dm_timer_pdev = of_find_device_by_node(timer);
> 
> So why not just do:
> 
> struct omap_dm_timer_ops *pdata =
> omap_dm_timer_get_ops(omap->dm_timer_pdev);

if you dont want to do additional optimizations as part of migration
might be
dev_get_platdata(&omap->dm_timer_pdev->dev);

would be enough.

But, again, PWM driver don't need to know so many details about
DM timer implementation and internal structure as consumer.

-- 
regards,
-grygorii