[U-Boot] [PATCH v2 5/7] tegra: Implement gpio_early_init() on Tamonten

Thierry Reding thierry.reding at avionic-design.de
Fri May 25 15:46:26 CEST 2012


The PI4 GPIO is used on Tamonten to reset carrier board peripherals.
Power sequencing hardware on the carrier pulls the reset low before
powering up the Tegra, and the CPU is supposed to signal readiness,
and therefore bring peripherals out of reset by pulling PI4 high.

Signed-off-by: Thierry Reding <thierry.reding at avionic-design.de>
---
Changes in v2:
- new patch required for TEC support

 board/avionic-design/common/tamonten.c |    9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/board/avionic-design/common/tamonten.c b/board/avionic-design/common/tamonten.c
index d9ecd23..2b19d1e 100644
--- a/board/avionic-design/common/tamonten.c
+++ b/board/avionic-design/common/tamonten.c
@@ -49,6 +49,15 @@ void gpio_config_uart(void)
 {
 }
 
+#ifdef CONFIG_BOARD_EARLY_INIT_F
+void gpio_early_init(void)
+{
+	gpio_request(GPIO_PI4, NULL);
+	gpio_direction_output(GPIO_PI4, 1);
+	gpio_free(GPIO_PI4);
+}
+#endif
+
 #ifdef CONFIG_TEGRA2_MMC
 /*
  * Routine: pin_mux_mmc
-- 
1.7.10.2



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