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

Nikolay Dimitrov
2014-10-07T21:55:02Z

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?

> +#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.

Reviewed-by: Nikolay Dimitrov <picmaster@mail.bg>

Kind regards,
Nikolay