Stephen,

-----Original Message----- From: Stephen Warren [mailto:swarren@wwwdotorg.org] Sent: Monday, January 18, 2016 11:23 AM To: u-boot@lists.denx.de; Simon Glass sjg@chromium.org; Tom Warren TWarren@nvidia.com; Stephen Warren swarren@nvidia.com Cc: Thierry Reding treding@nvidia.com Subject: [PATCH] ARM: tegra: rm Jetson TK1 PMIC GPIO programming

From: Stephen Warren swarren@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@nvidia.com

Acked-by: Tom Warren twarren@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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