Messages in this thread | | | Date | Tue, 09 Dec 2014 15:02:06 +0100 | From | Jacek Anaszewski <> | Subject | Re: [PATCH/RFC v9 04/19] mfd: max77693: adjust max77693_led_platform_data |
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On 12/09/2014 02:50 PM, Lee Jones wrote: > On Tue, 09 Dec 2014, Jacek Anaszewski wrote: > >> On 12/09/2014 11:04 AM, Lee Jones wrote: >>> On Tue, 09 Dec 2014, Jacek Anaszewski wrote: >>> >>>> On 12/09/2014 09:50 AM, Lee Jones wrote: >>>>> On Wed, 03 Dec 2014, Jacek Anaszewski wrote: >>>>> >>>>>> Add "label" array for Device Tree strings with the name of a LED device >>>>>> and make flash_timeout a two element array, for caching the sub-led >>>>>> related flash timeout. Added is also an array for caching pointers to the >>>>>> sub-nodes representing sub-leds. >>>>>> >>>>>> Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com> >>>>>> Acked-by: Kyungmin Park <kyungmin.park@samsung.com> >>>>>> Cc: Chanwoo Choi <cw00.choi@samsung.com> >>>>>> Cc: Lee Jones <lee.jones@linaro.org> >>>>>> --- >>>>>> include/linux/mfd/max77693.h | 4 +++- >>>>>> 1 file changed, 3 insertions(+), 1 deletion(-) >>>>>> >>>>>> diff --git a/include/linux/mfd/max77693.h b/include/linux/mfd/max77693.h >>>>>> index f0b6585..c80ee99 100644 >>>>>> --- a/include/linux/mfd/max77693.h >>>>>> +++ b/include/linux/mfd/max77693.h >>>>>> @@ -88,16 +88,18 @@ enum max77693_led_boost_mode { >>>>>> }; >>>>>> >>>>>> struct max77693_led_platform_data { >>>>>> + const char *label[2]; >>>>>> u32 fleds[2]; >>>>>> u32 iout_torch[2];for_each_available_child_of_node >>>>>> u32 iout_flash[2]; >>>>>> u32 trigger[2]; >>>>>> u32 trigger_type[2]; >>>>>> + u32 flash_timeout[2]; >>>>>> u32 num_leds; >>>>>> u32 boost_mode; >>>>>> - u32 flash_timeout; >>>>>> u32 boost_vout; >>>>>> u32 low_vsys; >>>>>> + struct device_node *sub_nodes[2]; >>>>> >>>>> I haven't seen anyone do this before. Why can't you use the provided >>>>> OF functions to traverse through your tree? >>>> >>>> I use for_each_available_child_of_node when parsing DT node, but I >>>> need to cache the pointer to sub-node to be able to use it later >>>> when it needs to be passed to V4L2 sub-device which is then >>>> asynchronously matched by the phandle to sub-node. >>>> >>>> If it is not well seen to cache it in the platform data then >>>> I will find different way to accomplish this. >>> >>> I haven't seen the end-driver for this, but why can't you use that >>> device's of_node pointer? >> >> Maybe it is indeed a good idea. I could pass the of_node pointer >> and the sub-led identifier to the V4L2 sub-device and there look >> for the sub-node containing relevant identifier. The downside >> would be only that for_each_available_child_of_node would >> have to be called twice - in the led driver and in the V4L2 sub-device. >> I think that we can live with it. > > Are the LED and V4L2 drivers children of this MFD? If so, you can use > the of_compatible attribute in struct mfd_cell to populate the each > child's of_node dynamically i.e. the MFD core will do that for you. >
V4L2 driver wraps LED driver. This way the LED device can be controlled with use of two interfaces - LED subsystem sysfs and V4L2 Flash. This is the aim of the whole patch set.
I've thought it over again and it seems that I will need to cache somewhere these sub_nodes pointers. They have to be easily accessible for the V4L2 sub-device as it can be asynchronously registered or unregistered within V4L2 media device. Sub-devices are matched basing on the sub-node phandle.
Best Regards, Jacek Anaszewski
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