From: Adam Shamblin <adam@vexingworkshop.com>
Date: Thu, 26 May 2022 23:02:29 +0000 (-0600)
Subject: Update readme, add additional gpio functions
X-Git-Url: https://git.vexinglabs.com/?a=commitdiff_plain;h=2bf199bf0cea2171457aa2d021d79ea0c291ac60;p=forthdeck.git

Update readme, add additional gpio functions
---

diff --git a/README.md b/README.md
index 345e8c2..aa90178 100644
--- a/README.md
+++ b/README.md
@@ -9,4 +9,46 @@ keywords:
 ---
 # ForthDeck
 
+The purpose of this project is to build a general purpose, interactive computer
+out of an rp2040, while learning practical programming using the Forth language.
 
+## GPIO
+
+*file: gpio.fs*
+
+### pin ( n -- addr )
+
+Given a pin number, return the pin's address on the IO bank.
+
+```forth
+13 pin
+```
+
+### funcsel@ ( addr -- n )
+
+Given a pin address, leave the number of the currently selected pin function on
+the stack.
+
+```forth
+13 pin funcsel@
+```
+
+### funcsel! ( addr n -- )
+
+Given a pin address and a function number (see GPIO pin constants), set the
+selected pin's function.
+
+```forth
+13 pin SIO funcsel!
+```
+
+## Terminal
+
+*file: terminal.fs*
+
+## TODO
+
+* Timers
+* Blocks
+* SPI
+* U2F image
diff --git a/gpio.fs b/gpio.fs
index 9101e23..dbf58b4 100644
--- a/gpio.fs
+++ b/gpio.fs
@@ -1,14 +1,5 @@
 \ Words for managing GPIO pins
 
-\ User bank IO registers
-$40014000       constant IO_BANK0_BASE
-$00000004       constant GPIO_CTRL
-$d0000000       constant SIO_BASE
-SIO_BASE $020 + constant GPIO_OE
-SIO_BASE $024 + constant GPIO_OE_SET
-SIO_BASE $028 + constant GPIO_OE_CLR
-SIO_BASE $02c + constant GPIO_OE_XOR
-
 \ GPIO pin functions
 1 constant SPI0
 2 constant UART
@@ -20,19 +11,33 @@ SIO_BASE $02c + constant GPIO_OE_XOR
 9 constant USB
 31 constant NULL
 
+\ User bank IO registers
+$40014000       constant IO_BANK0_BASE
+$00000004       constant GPIO_CTRL
+$d0000000       constant SIO_BASE
+SIO_BASE $004 + constant GPIO_IN
+SIO_BASE $010 + constant GPIO_OUT
+SIO_BASE $014 + constant GPIO_OUT_SET
+SIO_BASE $018 + constant GPIO_OUT_CLR
+SIO_BASE $01c + constant GPIO_OUT_XOR
+SIO_BASE $020 + constant GPIO_OE
+SIO_BASE $024 + constant GPIO_OE_SET
+SIO_BASE $028 + constant GPIO_OE_CLR
+SIO_BASE $02c + constant GPIO_OE_XOR
+
 \ Given a pin #, leave its address on the stack
 : pin ( n -- addr ) 8 * IO_BANK0_BASE + ;
 
 \ Given a pin address, leave its selected function value on the stack
-\ example: 13 pin funcsel
+\ example: 13 pin funcsel@
 : funcsel@ ( addr -- n ) GPIO_CTRL + @ ;
 
 \ Given a pin address, set its function
-\ example: 13 pin SIO funcset
+\ example: 13 pin SIO funcsel!
 : funcsel! ( addr n -- ) swap GPIO_CTRL + ! ;
 
 \ Display a list of all gpio pins and their current function
-: pins ( -- ) cr 30 0 DO I dup u. pin funcsel u. cr LOOP ;
+: pins ( -- ) cr 30 0 DO I dup u. pin funcsel@ u. cr LOOP ;
 
 \ Enable/disable pin for GPIO output
 \ example: 13 output-enable
@@ -41,4 +46,36 @@ SIO_BASE $02c + constant GPIO_OE_XOR
 : output-disable ( n -- ) 1 swap lshift GPIO_OE_CLR ! ;
 
 \ Check if pin has GPIO output enabled
+\ example: 13 output-enabled?
 : output-enabled? ( n -- flag ) 1 swap lshift GPIO_OE @ and 0 > ;
+
+\ Display a list of all gpio pins and their On/Off status
+: output-enabled. ( -- )
+  cr 30 0 DO I dup u.
+    output-enabled? IF ." On" ELSE ." Off" THEN
+  cr LOOP ;
+
+\ Set pin output to high
+\ example: 13 high
+\ example: 13 low
+\ example: 13 output .
+: high ( n -- ) 1 swap lshift GPIO_OUT_SET ! ;
+: low ( n -- ) 1 swap lshift GPIO_OUT_CLR ! ;
+: output? ( n -- flag ) 1 swap lshift GPIO_OUT @ and 0 > ;
+
+\ Display a list of all gpio pins and their output High/Low status
+: outputs. ( -- )
+  cr 30 0 DO I dup u.
+    output? IF ." High" ELSE ." Low" THEN
+  cr LOOP ;
+
+\ TODO I haven't read much about reading inputs yet, this will require fleshing out.
+: input@ ( n -- ? ) 1 swap lshift GPIO_IN @ ;
+
+: inputs. ( -- )
+  cr 30 0 DO I dup u.
+    input@ .
+  cr LOOP ;
+
+\ TODO Create a word to output a table containing selected function,
+\ output enabled, etc. for each pin.