[U-Boot] [PATCH V5] ARM: mx6: Add support for Kosagi Novena

[Sean Cross <xobs@kosagi.com>]

Hi Nikolay,

On 08/10/2014 23:35, picmaster at mail.bg wrote:
> Hi Sean,
>
> ----- ????? ?? Sean Cross (xobs at kosagi.com), ?? 08.10.2014 ? 10:47 -----
>
>> On 08/10/2014 05:55, Nikolay Dimitrov wrote:
>>> Hi Marek,
>>>
>>> I'm marking only the critical issues that are left unfixed from
>>> previous conversations, to speed-up the process a little bit.
>>> I'll send later patches for the non-critical issues to spare you the
>>> extra work (and I'm sure my constructive criticism is already boring
>>> :D ).
>>>
>>>
>>> On 10/06/2014 07:02 PM, Marek Vasut wrote:
>>>> +#define NOVENA_USB_HUB_RESET    IMX_GPIO_NR(7, 12)
>>> ...
>>>> +/*
>>>> + * USB
>>>> + */
>>>> +#ifdef CONFIG_USB_EHCI_MX6
>>>> +int board_ehci_hcd_init(int port)
>>>> +{
>>>> +    /* Reset USB hub */
>>>> +    if (port == 1) {
>>>> +        gpio_set_value(NOVENA_USB_HUB_RESET, 0);
>>>> +        mdelay(2);
>>>> +        gpio_set_value(NOVENA_USB_HUB_RESET, 1);
>>>> +    }
>>>> +    return 0;
>>>> +}
>>>> +#endif
>>> As we previously discussed, this pin definition conflicts with
>>> NOVENA_PCIE_POWER_ON_GPIO (GPIO7_IO12 is connected to PCIE_PWRON), so
>>> by asserting it, you'll turn-off the wrong sub-system.
>>>
>>> Currently the USB hub is reset only by system reset (RESETBMCU
>>> asserted by the PMIC). I don't see how the CPU can selectively reset
>>> the USB hub via a GPIO, so it would be better to remove the reset code.
>>>
>>> @Sean - can you please confirm/reject this finding?
> @Sean: Do you have any comments on USB hub reset stuff? Should we ditch
> entirely the reset code, or should we modify it somehow to work properly?
>
>
>>>> +#define NOVENA_AUDIO_PWRON        IMX_GPIO_NR(5, 17)
>>> ...
>>>> +/*
>>>> + * Audio
>>>> + */
>>>> +static iomux_v3_cfg_t audio_pads[] = {
>>>> +    /* AUD_PWRON */
>>>> +    MX6_PAD_DISP0_DAT23__GPIO5_IO17 | MUX_PAD_CTRL(NO_PAD_CTRL),
>>>> +};
>>> The speaker amplifiers will still be disabled, as AUDIO_PWRON is not
>>> connected to them (R30A is marked as DNP). You need to add one more
>>> GPIO to enable the speaker amplifiers, here's the fix:
>>>
>>> #define NOVENA_AUDIO_PWRON        IMX_GPIO_NR(5, 17)
>>> #define NOVENA_AUDIO_SPK_AMP_ON        IMX_GPIO_NR(4, 9)
>>>
>>> /*
>>>  * Audio
>>>  */
>>> static iomux_v3_cfg_t audio_pads[] = {
>>>     /* AUD_PWRON */
>>>     MX6_PAD_KEY_ROW1__GPIO5_IO17 | MUX_PAD_CTRL(NO_PAD_CTRL),
>>>
>>>     /* Speakers' amplifiers #SHDWN  */
>>>     MX6_PAD_KEY_ROW1__GPIO4_IO09 | MUX_PAD_CTRL(NO_PAD_CTRL),
>>> };
>>>
>>> static void novena_spl_setup_iomux_audio(void)
>>> {
>>>     imx_iomux_v3_setup_multiple_pads(audio_pads, ARRAY_SIZE(audio_pads));
>>>
>>>     gpio_direction_output(NOVENA_AUDIO_PWRON, 1);
>>>     gpio_direction_output(NOVENA_AUDIO_SPK_AMP_ON, 1);
>>> }
>>>
>>>
>>> Side comment: If someone needs to talk to the Audio Codec via I2C3 in
>>> U-Boot environment, don't be surprised if the codec doesn't respond to
>>> any I2C requests at all (I've had such issues with SGTL5000). The most
>>> probable reason is that the codec doesn't receive reference clock from
>>> imx6 GPIO0. This is not a critical issues as later the kernel muxes
>>> this GPIO0 properly, but keep this in mind if you want to hack the
>>> audio-codec at low level.
>> The audio codec ought to answer even when the reference clock isn't
>> active.  I actually can't recall, but I think the digital side still
>> works.
> Well, that would be great if it works out this way. I just shared what
> happened with another audio codec, to spare some frustration to others.
>
>
>> The audio codec needs to be turned on because otherwise it will
>> pull the SCL and SCK lines low, blocking I2C3 from working at all.
> Agreed.
>
>
>> Actually, now that I'm looking at it, we just had to make an ECO to get
>> rid of SPK_AMP_ON.  It is now ganged to AUDIO_PWRON, because SPK_AMP_ON
>> was accidentally dual-purposed as a GPIO for the front button on the
>> desktop / laptop.  This change was made very recently (last Friday I
>> think), and we'll be switching resistors on the mainboard when they're
>> built in order to make the change.
> Well, all I have is the Novena schematic (http://bunniefoo.com/novena/pvt2_release/novena_pvt2.PDF) so all my analysis is based on this PDF. On page 14, R30A is
> DNP, and R28A is populated, this is why I suggested this modification to enable
> speaker amps. If there are schematic changes, please publish the new version
> so we can use the proper schematic and reduce spam.
>
> @Marek: According to this latest update, there's no need for my fix for
> NOVENA_AUDIO_SPK_AMP_ON, as your original code will work just fine with the
> planned schematic changes. Please disregard the fix.

I'll be sure to have Bunnie post a new schematic when he returns
tomorrow.  For now, the ECO on our wiki is the authoritative source. 
This is curently the only ECO for the final PVT2 board:
http://www.kosagi.com/w/index.php?title=Novena_PVT2_ECO_List#ECO22:_swap_audio_control_option


Sean