[U-Boot] [PATCH] x86: minnowmax: add GPIO mapping support

[Bin Meng]

Hi Gabriel,

On Fri, Feb 27, 2015 at 3:54 PM, gabriel huau <contact at huau-gabriel.fr> wrote:
> Hi Bin,
>
>
> On 02/26/2015 07:30 PM, Bin Meng wrote:
>>
>> Hi Gabriel,
>>
>> On Thu, Feb 26, 2015 at 12:27 AM, Gabriel Huau <contact at huau-gabriel.fr>
>> wrote:
>>>
>>> Hi Bin,
>>>
>>>
>>> On 02/24/2015 11:52 PM, Bin Meng wrote:
>>>>
>>>> Hi Gabriel,
>>>>
>>>> On Mon, Feb 16, 2015 at 5:55 AM, Gabriel Huau <contact at huau-gabriel.fr>
>>>> wrote:
>>>>>
>>>>> Configure the pinctrl as it required to make some IO controllers
>>>>> working (USB/UART/I2C/...).
>>>>> The idea would be in the next version to modify the pch GPIO driver and
>>>>> configure these pins through the device tree.
>>>>>
>>>>> These modifications are ported from the coreboot project.
>>>>>
>>>>> Signed-off-by: Gabriel Huau <contact at huau-gabriel.fr>
>>>>> ---
>>>>>    arch/x86/cpu/baytrail/Makefile                |   1 +
>>>>>    arch/x86/cpu/baytrail/gpio.c                  | 206 +++++++++++++++
>>>>>    arch/x86/include/asm/arch-baytrail/gpio.h     | 364
>>>>> ++++++++++++++++++++++++++
>>>>>    arch/x86/include/asm/arch-baytrail/iomap.h    |  73 ++++++
>>>>>    arch/x86/include/asm/arch-baytrail/irq.h      | 119 +++++++++
>>>>>    arch/x86/include/asm/arch-baytrail/irqroute.h |  67 +++++
>>>>>    arch/x86/include/asm/arch-baytrail/pci_devs.h | 144 ++++++++++
>>>>>    arch/x86/include/asm/arch-baytrail/pmc.h      | 253
>>>>> ++++++++++++++++++
>>>>>    board/intel/minnowmax/minnowmax.c             | 212 +++++++++++++++
>>>>>    include/configs/minnowmax.h                   |  11 +
>>>>>    10 files changed, 1450 insertions(+)
>>>>>    create mode 100644 arch/x86/cpu/baytrail/gpio.c
>>>>>    create mode 100644 arch/x86/include/asm/arch-baytrail/iomap.h
>>>>>    create mode 100644 arch/x86/include/asm/arch-baytrail/irq.h
>>>>>    create mode 100644 arch/x86/include/asm/arch-baytrail/irqroute.h
>>>>>    create mode 100644 arch/x86/include/asm/arch-baytrail/pci_devs.h
>>>>>    create mode 100644 arch/x86/include/asm/arch-baytrail/pmc.h
>>>>>
>>>> [snip]
>>>>
>>>>> diff --git a/include/configs/minnowmax.h b/include/configs/minnowmax.h
>>>>> index 823e051..738c6fa 100644
>>>>> --- a/include/configs/minnowmax.h
>>>>> +++ b/include/configs/minnowmax.h
>>>>> @@ -69,4 +69,15 @@
>>>>>    /* Avoid a warning in the Realtek Ethernet driver */
>>>>>    #define CONFIG_SYS_CACHELINE_SIZE 16
>>>>>
>>>>> +/*
>>>>> + * Baytrail has 3 GPIOs bank over PCI, there is no
>>>>> + * driver at the moment so let's disable the command
>>>>> + * and the default x86 driver to avoid any collision
>>>>> + * with the GPIO mapping code.
>>>>> + * @TODO: adding a baytrail-gpio driver and configure
>>>>> + * the muxing through the device tree
>>>>> + */
>>>>> +#undef CONFIG_INTEL_ICH6_GPIO
>>>>> +#undef CONFIG_CMD_GPIO
>>>>> +
>>>>
>>>> Why undef these two? The BayTrail SoC does support GPIO banks in the
>>>> legacy bridge.
>>>
>>> I might misunderstood the GPIO subsystem but I thought there was 2 banks
>>> available through the PCU iLB GPIO controller which contains the SCORE
>>> and
>>> SSUS (102 / 44 pins).
>>> The intel_ich6_gpio has a limitation of 32 GPIOs per bank and I thought
>>> it
>>> was just a different controller from the Baytrail, but if I can use it to
>>> control all the GPIOs + doing the IO mapping, I'll be glad to do it!
>>
>> I checked the BayTrail datasheet. Its GPIO is in the iLB (legacy
>> bridge), which is the same as other IA chipset (Ivybridge,
>> TunnelCreek, Quark). It has 4 banks in core domain and 2 banks in sus
>> domain. So 6 banks in total. You need define 6 gpio nodes in the
>> minnowmax board dts file. You should be able to use the existing gpio
>> driver to configure.
>
>
> Thanks for the clarification!
> Actually, I saw it today when I was doing some tests and I configured the 6
> banks in the devices tree. I also fixed the GPIO base address to 0x48 but I
> got some issues like the fact I'm reading only 0 from all the registers.

Yep, the offset should be 0x48 for BayTrail.

> The registers are configured to be in the IO Space (0x500), I checked the
> PCI configuration space to make sure that everything is enabled correctly,
> but I'm still missing something.

I checked the gpio driver codes, and it currently has:

        /*
         * Okay, I guess we're looking at the right device. The actual
         * GPIO registers are in the PCI device's I/O space, starting
         * at the offset that we just read. Bit 0 indicates that it's
         * an I/O address, not a memory address, so mask that off.
         */
        gpiobase = tmplong & 0xfffe;

This should be changed to

        gpiobase = tmplong & 0xfffc;

as bit1 is the enable bit on BayTrail (Intel changes this GPIO base
register again for BayTrail, sigh...)

> Once I'll be able to use these GPIOs, I will update the entire patch to
> remove the port from Coreboot as this is not necessary.
>
>>>>>    #endif /* __CONFIG_H */
>>>>> --

Regards,
Bin