first commit

Bash version. Requires `devmem2`. Run this script at boot time to restore the gpio pins on the 40 pin connector to the correct state.

gpio_fixup.sh

@@ -0,0 +1,77 @@
+#!/bin/bash
+# correct the GPIO settings to match the stated values in the i96 bus spec
+#
+# Pat Beirne <patb@pbeirne> 2021
+# 
+# this script applies only to the OrangePi-i96, booting from u-boot 2012.04.442
+
+echo "OrangePi-i96 fixup GPIO pins"
+echo "Version 1.0"
+
+# assert the i96 GPIO pins into GPIO mode
+PORTC_GPIO_MASK=0           # no pins need changing
+PORTA_GPIO_MASK=0x7e508000  # rda gpioA 15,20,22,25-30 (i96 gpio group)
+PORTB_GPIO_MASK=0           # no pins need changing
+PORTD_GPIO_MASK=0xc         # rda gpioD 2,3 (i96 gpioi group)
+PORTB_GPIO_MASK_NO_CTSRTS=0x0x300  # assert B 8,9 to reuse uart2_cts,rts
+
+# clear the i96 GPIO pins to special function mode
+PORTC_SF_MASK=0xfffffe3f  # clear bits C c6,7,8 (i96 uarts)
+PORTA_SF_MASK=0xffff91a0  # clear bits A 0-4,6,9-11,13,14 (i96 i2c, spi, i2s)
+PORTB_SF_MASK=0xfffffc3f  # clear bits B 6-9 (i96 i2c, uart)
+PORTD_SF_MASK=0xFFFFFFFF  # nothing to change
+
+PORTC_IOMUX=0x11a09008
+PORTA_IOMUX=0x11a0900c
+PORTB_IOMUX=0x11a09010
+PORTD_IOMUX=0x11a09014
+
+DEVMEM=''
+if [[ -x /usr/bin/devmem2 ]] 
+then
+  DEVMEM='/usr/bin/devmem2'
+elif [[ -x /usr/local/bin/devmem2 ]] 
+then
+  DEVMEM='/usr/localbin/devmem2'
+elif [[ -x /usr/local/bin/devmem2.py ]] 
+then
+  DEVMEM='/usr/local/bin/devmem2.py'
+else
+  echo "devmem2 not installed, no fixup done" 
+  return 1
+fi
+
+get_word() {
+  A=`$DEVMEM $1`
+  A=${A#*: }
+  echo $A
+}
+
+# call or_bits with <announcement> <iomux_address> <or_bitmask>
+# to set the bits (change to gpio)
+
+or_bits() {
+  echo "===" $1 "==="
+  READ_VALUE=`get_word $2`
+  WRITE_VALUE=$(($READ_VALUE | $3))
+  $DEVMEM $2 w $WRITE_VALUE >> /dev/null
+  echo "read:" $READ_VALUE " write:" `printf '0x%x' $WRITE_VALUE` "readback: " `get_word $2`
+}
+
+or_bits "PORTC set GPIO" $PORTC_IOMUX $PORTC_GPIO_MASK 
+or_bits "PORTA set GPIO" $PORTA_IOMUX $PORTA_GPIO_MASK 
+or_bits "PORTB set GPIO" $PORTB_IOMUX $PORTB_GPIO_MASK 
+or_bits "PORTD set GPIO" $PORTD_IOMUX $PORTD_GPIO_MASK 
+
+and_bits() {
+  echo "===" $1 "==="
+  READ_VALUE=`get_word $2`
+  WRITE_VALUE=$(($READ_VALUE & $3))
+  $DEVMEM $2 w $WRITE_VALUE >> /dev/null
+  echo "read:" $READ_VALUE " write:" `printf '0x%x' $WRITE_VALUE` "readback: " `get_word $2`
+}
+
+and_bits "PORTC set SPECIAL FUNCTION" $PORTC_IOMUX $PORTC_SF_MASK 
+and_bits "PORTA set SPECIAL FUNCTION" $PORTA_IOMUX $PORTA_SF_MASK 
+and_bits "PORTB set SPECIAL FUNCTION" $PORTB_IOMUX $PORTB_SF_MASK 
+