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authorEdoardo Scaglia <edoardo.87@gmail.com>2019-02-01 16:43:46 +0100
committerKoen Vandeputte <koen.vandeputte@ncentric.com>2019-02-08 17:27:47 +0100
commit077253dd666a30ae5231c3748222d4b5b138593d (patch)
treef0641d5b445ad56e09121cb030507528b636e99e
parent07e6ce4606474643cf4e8fee355b9126eb55c962 (diff)
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ar71xx: fix Arduino Yun enabling of level shifters outputs
As show in Arduino Yun schematic [1] GPIO 21 and 22 are connected to output enable pin (OE) of two NTB01xx level shifters. NTB01xx datasheets [2] [3] states that OE pin are active-high therefore we should initialize GPIO 21 (DS_GPIO_OE) and GPIO 22 (DS_GPIO_OE2) accordingly to actually enable level shifters outputs. [1] https://www.arduino.cc/en/uploads/Main/arduino-Yun-schematic.pdf [2] https://www.nxp.com/docs/en/data-sheet/NTB0102.pdf [3] https://www.nxp.com/docs/en/data-sheet/NTB0104.pdf Signed-off-by: Edoardo Scaglia <edoardo.87@gmail.com>
-rw-r--r--target/linux/ar71xx/files/arch/mips/ath79/mach-arduino-yun.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/target/linux/ar71xx/files/arch/mips/ath79/mach-arduino-yun.c b/target/linux/ar71xx/files/arch/mips/ath79/mach-arduino-yun.c
index 5873248edf..e92f68f490 100644
--- a/target/linux/ar71xx/files/arch/mips/ath79/mach-arduino-yun.c
+++ b/target/linux/ar71xx/files/arch/mips/ath79/mach-arduino-yun.c
@@ -141,7 +141,7 @@ static void __init ds_setup(void)
// enable OE of level shifter
if (gpio_request_one(DS_GPIO_OE,
- GPIOF_OUT_INIT_LOW | GPIOF_EXPORT_DIR_FIXED, "OE-1") != 0)
+ GPIOF_OUT_INIT_HIGH | GPIOF_EXPORT_DIR_FIXED, "OE-1") != 0)
printk("Error setting GPIO OE\n");
if (gpio_request_one(DS_GPIO_UART_ENA,
@@ -150,7 +150,7 @@ static void __init ds_setup(void)
// enable OE of level shifter
if (gpio_request_one(DS_GPIO_OE2,
- GPIOF_OUT_INIT_LOW | GPIOF_EXPORT_DIR_FIXED, "OE-2") != 0)
+ GPIOF_OUT_INIT_HIGH | GPIOF_EXPORT_DIR_FIXED, "OE-2") != 0)
printk("Error setting GPIO OE2\n");
}