[PATCH v9] ath10k: add LED and GPIO controlling support for various chipsets

[Steve deRosier]

Hi Sebastian,

On Thu, Feb 22, 2018 at 6:09 PM, Sebastian Gottschall
<s.gottschall at dd-wrt.com> wrote:
> Am 22.02.2018 um 23:17 schrieb Steve deRosier:
>>
>> On Thu, Feb 22, 2018 at 3:15 AM,  <s.gottschall at dd-wrt.com> wrote:
>>>
>>> From: Sebastian Gottschall <s.gottschall at newmedia-net.de>
>>>
>>> Adds LED and GPIO Control support for 988x, 9887, 9888, 99x0, 9984 based
>>> chipsets with on chipset connected led's
>>> using WMI Firmware API.
>>> The LED device will get available named as "ath10k-phyX" at sysfs and can
>>> be controlled with various triggers.
>>> adds also debugfs interface for gpio control.
>>>
>>> Signed-off-by: Sebastian Gottschall <s.gottschall at dd-wrt.com>
>>>
>>> v2  add correct gpio count per chipset and remove IPQ4019 support since
>>> this chipset does not make use of specific gpios)
>>> v5  fix compiling without LED_CLASS and GPIOLIB support, fix also error
>>> by kbuild test robot which does not occur in standard builds. curious
>>> v6  correct return values and fix comment style
>>> v7  fix ath10k_unregister_led for compiling without LED_CLASS
>>> v8  fix various code design issues reported by reviewers
>>> v9  move led and led code to separate sourcefile (gpio.c)
>>> ---
>>>   drivers/net/wireless/ath/ath10k/Kconfig   |   3 +
>>>   drivers/net/wireless/ath/ath10k/Makefile  |   1 +
>>>   drivers/net/wireless/ath/ath10k/core.c    |  28 ++++-
>>>   drivers/net/wireless/ath/ath10k/core.h    |  33 ++++-
>>>   drivers/net/wireless/ath/ath10k/debug.c   | 142 ++++++++++++++++++++++
>>>   drivers/net/wireless/ath/ath10k/gpio.c    | 196
>>> ++++++++++++++++++++++++++++++
>>>   drivers/net/wireless/ath/ath10k/hw.h      |   2 +
>>>   drivers/net/wireless/ath/ath10k/mac.c     |   5 +
>>>   drivers/net/wireless/ath/ath10k/wmi-ops.h |  36 +++++-
>>>   drivers/net/wireless/ath/ath10k/wmi-tlv.c |  65 ++++++++++
>>>   drivers/net/wireless/ath/ath10k/wmi.c     |  46 +++++++
>>>   drivers/net/wireless/ath/ath10k/wmi.h     |  36 ++++++
>>>   12 files changed, 590 insertions(+), 3 deletions(-)
>>>   create mode 100644 drivers/net/wireless/ath/ath10k/gpio.c
>>>
>>> diff --git a/drivers/net/wireless/ath/ath10k/Kconfig
>>> b/drivers/net/wireless/ath/ath10k/Kconfig
>>> index deb5ae21a559..c46b7658a820 100644
>>> --- a/drivers/net/wireless/ath/ath10k/Kconfig
>>> +++ b/drivers/net/wireless/ath/ath10k/Kconfig
>>> @@ -2,6 +2,9 @@ config ATH10K
>>>           tristate "Atheros 802.11ac wireless cards support"
>>>           depends on MAC80211 && HAS_DMA
>>>          select ATH_COMMON
>>> +        select MAC80211_LEDS
>>> +        select LEDS_CLASS
>>> +        select NEW_LEDS
>>>          select CRC32
>>>          select WANT_DEV_COREDUMP
>>>           ---help---
>>
>> Pure question: do we require LEDS, or is this an option? I assumed all
>> along it was an optional thing - ie if GPIOs and/or LEDs were
>> configured, we added this code. And if not optional, then what happens
>> if we are on a platform that can't support LEDS_CLASS or NEW_LEDS,
>> assuming there is such a thing?
>
> i took this behaviour from ath9k/ath5k, both driver auto select
> MAC80211_LEDS and LEDS_CLASS (by the way MAC80211_LEDS auto selects
> LEDS_CLASS too).  only chipsets which are known to have preconfigured leds
> are used
> and led will only turn on if you enable it in sysfs by assigning a trigger
> to the led.
> for sure this can be removed from the Kconfig. it will compile without it as
> well. so this is optional. i just added it since all other drivers behave in
> the same way.
> in addition. LEDS_CLASS  / NEW_LEDS is a kernel api, not a driver. so all
> platforms to support LEDS_CLASS. just enabling LEDS_CLASS will not cause any
> platform specific dependency.
>>
>>
>>
>>> diff --git a/drivers/net/wireless/ath/ath10k/Makefile
>>> b/drivers/net/wireless/ath/ath10k/Makefile
>>> index 6739ac26fd29..bcb234f0b940 100644
>>> --- a/drivers/net/wireless/ath/ath10k/Makefile
>>> +++ b/drivers/net/wireless/ath/ath10k/Makefile
>>> @@ -20,6 +20,7 @@ ath10k_core-$(CONFIG_NL80211_TESTMODE) += testmode.o
>>>   ath10k_core-$(CONFIG_ATH10K_TRACING) += trace.o
>>>   ath10k_core-$(CONFIG_THERMAL) += thermal.o
>>>   ath10k_core-$(CONFIG_MAC80211_DEBUGFS) += debugfs_sta.o
>>> +ath10k_core-y += gpio.o
>>>   ath10k_core-$(CONFIG_PM) += wow.o
>>>   ath10k_core-$(CONFIG_DEV_COREDUMP) += coredump.o
>>>
>> I'd expect it would be something like `ath10k_core-$(CONFIG_GPIO) +=
>> gpoi.o`.  Maybe I'm mistaken.
>
> gpio.c contains the MAC80211_LEDS code and has a guard for GPIOLIB inside.
> it can be compiled even if GPIOLIB is disabled in system. (which is indeed
> platform specific)
> and leds are still supported without gpio support since it does contain a
> led only driver and a separate gpio driver.
> i suggest more somelike like
>
> ath10k_core-$(ATH10K_LEDS) += gpio.o
>
> if you want it totally optional which requires some other small changes as
> well (mainly renaming some ifdefs)
>
>> (Note, I didn't look up the actual config option name, I'm guessing.
>> Assume I wrote something reasonable for my example.)
>>
>> I only ask the above two questions, not because I think it's wrong,
>> but because I don't quite know the intention and it makes me wonder.
>>
>> Other than those questions, which are optional as the code looks
>> correct to me, the rest of it looks fine to me.
>
> i fully understand your concerns, i just followed other drivers behaviour.
> for sure its more sane to make it optional and to compile it out of not
> required.
> but then i suggest todo the same in ath5k and ath9k
>

Your explanation is fine with me. Consistency with other drivers makes
perfect sense. And I happen to agree with your thought, that it should
be fixed in the other drivers. But that doesn't seem like it should
have to be done right now. Thanks for explaining.

I think this is good to go as long as no one else has issues with it.

>>
>> Reviewed-by: Steve deRosier <derosier at cal-sierra.com>
>>

Thanks,
- Steve