[PATCH 8/8] arm64: dts: hikey: Fix WiFi support

[John Stultz]

On Mon, Jun 5, 2017 at 8:15 AM, Ulf Hansson <ulf.hansson at linaro.org> wrote:
> On 1 June 2017 at 22:57, John Stultz <john.stultz at linaro.org> wrote:
>> On Wed, May 31, 2017 at 11:36 AM, Daniel Lezcano
>> <daniel.lezcano at linaro.org> wrote:
>>> On 31/05/2017 20:14, John Stultz wrote:
>>>> On Mon, May 8, 2017 at 9:21 AM, Ulf Hansson <ulf.hansson at linaro.org> wrote:
>>>>> The description of the connection between the dwmmc (SDIO) controller and
>>>>> the Wifi chip, which is attached to the SDIO bus is wrong. Currently the
>>>>> SDIO card can't be detected and thus the Wifi doesn't work.
>>>>>
>>>>> Let's fix this by assigning the correct vmmc supply, which is the always on
>>>>> regulator VDD_3V3 and remove the WLAN enable regulator altogether. Then to
>>>>> properly deal with the power on/off sequence, add a mmc-pwrseq node to
>>>>> describe the resources needed to detect the SDIO card.
>>>>>
>>>>> Except for the WLAN enable GPIO and its corresponding assert/de-assert
>>>>> delays, the mmc-pwrseq node also contains a handle to a clock provided by
>>>>> the hi655x pmic. This clock is also needed to be able to turn on the WiFi
>>>>> chip.
>>>>>
>>>>> Signed-off-by: Ulf Hansson <ulf.hansson at linaro.org>
>>>>
>>>>
>>>> Ulf,
>>>>   So oddly, this patch seems to have broken wifi on HiKey when it
>>>> landed in 4.12-rc3. I checked my config and CONFIG_PWRSEQ_SIMPLE is
>>>> enabled.
>>>
>>> Hi John,
>>>
>>> how is it possible the WiFi stops working with this series? This series
>>> provides the missing bits to enable the WiFi with a vanilla kernel.
>>>
>>> May be the WiFi is reset with this kernel and when it starts again the
>>> firmware fails to load because it is not up-to-date?
>>>
>>> Can you check in dmesg if there is a firmware error message?
>>
>> So, it seems to me to be connected to some of the tweaks to the mmc2 dts node.
>>
>> When it works I see:
>>  dwmmc_k3 f723f000.dwmmc2: Using internal DMA controller.
>>  dwmmc_k3 f723f000.dwmmc2: Version ID is 250a
>>  dwmmc_k3 f723f000.dwmmc2: DW MMC controller at irq 43,32 bit host
>> data width,128 deep fifo
>>  mmc_host mmc2: card is non-removable.
>>  mmc_host mmc2: Bus speed (slot 0) = 24800000Hz (slot req 400000Hz,
>> actual 400000HZ div = 31)
>>  dwmmc_k3 f723f000.dwmmc2: 1 slots initialized
>>  dwmmc_k3 f723f000.dwmmc2: card claims to support voltages below defined range
>>  mmc_host mmc2: Bus speed (slot 0) = 24800000Hz (slot req 25000000Hz,
>> actual 24800000HZ div = 0)
>>  mmc2: new SDIO card at address 0001
>>  wl18xx_driver wl18xx.4.auto: Direct firmware load for
>> ti-connectivity/wl18xx-conf.bin failed with error -2
>>  wl18xx_driver wl18xx.4.auto: Falling back to user helper
>>
>> When it fails:
>>  dwmmc_k3 f723f000.dwmmc2: fifo-depth property not found, using value
>> of FIFOTH register as default
>>  dwmmc_k3 f723f000.dwmmc2: IDMAC supports 32-bit address mode.
>>  dwmmc_k3 f723f000.dwmmc2: Using internal DMA controller.
>>  dwmmc_k3 f723f000.dwmmc2: Version ID is 250a
>>  dwmmc_k3 f723f000.dwmmc2: DW MMC controller at irq 43,32 bit host
>> data width,128 deep fifo
>>
>> is seen repeatedly.
>>
>>
>> I'm using my branch here (using the hikey_defconfig included):
>> https://git.linaro.org/people/john.stultz/android-dev.git dev/hikey-mainline-WIP
>
> John, thanks for the report!
>
> After a some investigation, I realized that the mmc pwrseq_simple
> driver returns -EPROBE_DEFER as it's not able to get the "ext" clock.
> Hence the SDIO card will not be detected.
>
> To fix the problem, you need to enable CONFIG_COMMON_CLK_HI655X in the
> kernel config. This is actually also the case when using the arm64
> defconfig for a plain 4.12 rc3 and later. We should probably make this
> driver enabled per default when building the arm64 defconfig.

Ah! Thanks for this!

Would it make sense to have the hi6220 clk select this if its
required? I had thought the Hi655x was a different SoC, not just a
PMIC.  Expecting users to be able to figure any of this out doesn't
seem reasonable.


> Can you run a re-test at your side with the CONFIG_COMMON_CLK_HI655X
> set? Just to make sure it works also with those boot binaries you are
> using...

Yep. With that it seems to work alright. I'll let you know if I see
any further problems as I continue to use it.

Thanks again for the help sorting this out!
-john