[U-Boot] [PATCH] ARM: tegra: rm Jetson TK1 PMIC GPIO programming

[Tom Warren]

Stephen,

> -----Original Message-----
> From: Stephen Warren [mailto:swarren at wwwdotorg.org]
> Sent: Monday, January 18, 2016 11:23 AM
> To: u-boot at lists.denx.de; Simon Glass <sjg at chromium.org>; Tom Warren
> <TWarren at nvidia.com>; Stephen Warren <swarren at nvidia.com>
> Cc: Thierry Reding <treding at nvidia.com>
> Subject: [PATCH] ARM: tegra: rm Jetson TK1 PMIC GPIO programming
> 
> From: Stephen Warren <swarren at nvidia.com>
> 
> The PMIC is configured such that its GPIOs have the correct configuration at
> power-up, so no programming is required.
> 
> In fact, the current programming is actively wrong, since:
> 
> (a) the AS3722 driver configures the GPIO to be an output before setting its
> output value, which causes a 0v glitch on the output.
> 
> (b) the AS3722 driver configures the GPIO to drive a high voltage from its
> VSUP_GPIO power source rather than its VDD_GPIO_LV power source, so the
> pin drives 5V not 1.8V as desired.
> 
> Solve these problems by removing the code which configures the PMIC GPIOs.
> 
> Note that this patch was tested directly on top of v2016.01; since then, commit
> 96350f729c42 "dm: tegra: net: Convert tegra boards to driver model for
> Ethernet" prevents PCIe from being initialized. Alternatively, simply revert that
> commit to get PCIe Ethernet working again, then apply this patch to test.
> 
> Signed-off-by: Stephen Warren <swarren at nvidia.com>
Acked-by: Tom Warren <twarren at nvidia.com>
I'll apply this to u-boot-tegra/next ASAP.

> ---
>  board/nvidia/jetson-tk1/jetson-tk1.c | 13 -------------
>  1 file changed, 13 deletions(-)
> 
> diff --git a/board/nvidia/jetson-tk1/jetson-tk1.c b/board/nvidia/jetson-
> tk1/jetson-tk1.c
> index e929a1c1ea27..a66b710cddab 100644
> --- a/board/nvidia/jetson-tk1/jetson-tk1.c
> +++ b/board/nvidia/jetson-tk1/jetson-tk1.c
> @@ -60,19 +60,6 @@ int tegra_pcie_board_init(void)
>  		return err;
>  	}
> 
> -	err = as3722_gpio_configure(pmic, 1, AS3722_GPIO_OUTPUT_VDDH |
> -					     AS3722_GPIO_INVERT);
> -	if (err < 0) {
> -		error("failed to configure GPIO#1 as output: %d\n", err);
> -		return err;
> -	}
> -
> -	err = as3722_gpio_direction_output(pmic, 2, 1);
> -	if (err < 0) {
> -		error("failed to set GPIO#2 high: %d\n", err);
> -		return err;
> -	}
> -
>  	return 0;
>  }
>  #endif /* PCI */
> --
> 2.7.0

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