Allow using Pico-W WL_GPIO pins with gpio nifs

Modifies the Pico gpio dirver to accept atoms for the special wl_gpio pins
present in the Pico-W.
- Adds support for `wl0` and `wl1` as output pins in `gpio:digital_write/2`.
- Adds support for `wl2` as an input pin in `gpio:digital_read/1`.

Signed-off-by: Winford <winford@object.stream>

CHANGELOG.md

@@ -20,6 +20,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Added cmake configuration option `AVM_CONFIG_REBOOT_ON_NOT_OK` for STM32
 - New gpio driver for STM32 with nif and port support for read and write functions.
 - Added support for interrupts to STM32 GPIO port driver.
+- Added suppoprt for PicoW extra gpio pins (led) to the gpio driver.
 
 ## [0.6.0-alpha.1] - 2023-10-09
 

libs/eavmlib/src/gpio.erl

@@ -59,11 +59,11 @@
 -type gpio() :: pid().
 %% This is the pid returned by `gpio:start/0'.
 -type pin() :: non_neg_integer() | pin_tuple().
-%% The pin definition for ESP32 and PR2040 is a non-negative integer, on the STM32 platform it is a tuple.
+%% The pin definition for ESP32 and PR2040 is a non-negative integer. A tuple is used on the STM32 platform and for the extra "WL" pins on the Pico-W.
 -type pin_tuple() :: {gpio_bank(), 0..15}.
-%% A pin parameter on STM32 is a tuple consisting of a GPIO bank and pin number.
--type gpio_bank() :: a | b | c | d | e | f | g | h | i | j | k.
-%% STM32 gpio banks vary by board, some only break out `a' thru `h'.
+%% A pin parameter on STM32 is a tuple consisting of a GPIO bank and pin number, also used on the Pico-W for the extra "WL" pins `0..2'.
+-type gpio_bank() :: a | b | c | d | e | f | g | h | i | j | k | wl.
+%% STM32 gpio banks vary by board, some only break out `a' thru `h'. The extra "WL" pins on Pico-W use bank `wl'.
 -type direction() :: input | output | output_od | mode_config().
 %% The direction is used to set the mode of operation for a GPIO pin, either as an input, an output, or output with open drain.
 %% On the STM32 platform pull mode and output_speed must be set at the same time as direction. See @type mode_config()
@@ -438,6 +438,9 @@ deep_sleep_hold_dis() ->
 %%          on a specific bank the atom `all' may be used, this will have no effect on any pins on the
 %%          same bank that have been configured as inputs, so it is safe to use with mixed direction
 %%          modes on a bank.
+%%
+%%          The LED pin on the Pico-W can be controlled on the extended pin `{wl, 0}', and does not
+%%          require or accept `set_pin_mode' or `set_pin_pull' before use.
 %% @end
 %%-----------------------------------------------------------------------------
 -spec digital_write(Pin :: pin(), Level :: level()) -> ok | {error, Reason :: atom()} | error.
@@ -452,6 +455,9 @@ digital_write(_Pin, _Level) ->
 %%          Read if an input pin state is high or low.
 %%          Warning: if the pin was not previously configured as an input using
 %%          `gpio:set_pin_mode/2' it will always read as low.
+%%
+%%          The VBUS detect pin on the Pico-W can be read on the extended pin `{wl, 2}',
+%%          and does not require or accept `set_pin_mode' or `set_pin_pull' before use.
 %% @end
 %%-----------------------------------------------------------------------------
 -spec digital_read(Pin :: pin()) -> high | low | {error, Reason :: atom()} | error.

src/platforms/rp2040/src/lib/gpiodriver.c

@@ -30,6 +30,8 @@
 #include "rp2040_sys.h"
 #include "trace.h"
 
+#define WL_ATOM globalcontext_make_atom(ctx->global, ATOM_STR("\x2", "wl"))
+
 static const struct Nif *gpio_nif_get_nif(const char *nifname);
 
 static const AtomStringIntPair pin_mode_table[] = {
@@ -66,13 +68,22 @@ static const AtomStringIntPair pin_level_table[] = {
     SELECT_INT_DEFAULT(AtomVMRP2040GPIOInvalid)
 };
 
+// #ifdef LIB_PICO_CYW43_ARCH
+// static const AtomStringIntPair wl_pin_table[] = {
+//     { ATOM_STR("\x3", "wl0"), 0 },
+//     { ATOM_STR("\x3", "wl1"), 1 },
+//     { ATOM_STR("\x3", "wl2"), 2 },
+//     SELECT_INT_DEFAULT(-1)
+// };
+// #endif
+
 static term nif_gpio_init(Context *ctx, int argc, term argv[])
 {
     UNUSED(ctx);
     UNUSED(argc);
 
     VALIDATE_VALUE(argv[0], term_is_integer);
-    int pin = term_to_int(argv[0]);
+    uint pin = term_to_int(argv[0]);
     gpio_init(pin);
     return OK_ATOM;
 }
@@ -83,7 +94,7 @@ static term nif_gpio_deinit(Context *ctx, int argc, term argv[])
     UNUSED(argc);
 
     VALIDATE_VALUE(argv[0], term_is_integer);
-    int gpio_num = term_to_int(argv[0]);
+    uint gpio_num = term_to_int(argv[0]);
     gpio_deinit(gpio_num);
     return OK_ATOM;
 }
@@ -93,10 +104,10 @@ static term nif_gpio_set_pin_mode(Context *ctx, int argc, term argv[])
     UNUSED(argc);
 
     VALIDATE_VALUE(argv[0], term_is_integer);
-    int gpio_num = term_to_int(argv[0]);
+    uint gpio_num = term_to_int(argv[0]);
     int mode = interop_atom_term_select_int(pin_mode_table, argv[1], ctx->global);
     if (UNLIKELY(mode < 0)) {
-        return ERROR_ATOM;
+        RAISE_ERROR(BADARG_ATOM);
     }
     gpio_set_dir(gpio_num, mode);
     return OK_ATOM;
@@ -107,7 +118,7 @@ static term nif_gpio_set_pin_pull(Context *ctx, int argc, term argv[])
     UNUSED(argc);
 
     VALIDATE_VALUE(argv[0], term_is_integer);
-    int gpio_num = term_to_int(argv[0]);
+    uint gpio_num = term_to_int(argv[0]);
     int pull_mode = interop_atom_term_select_int(pull_mode_table, argv[1], ctx->global);
     gpio_set_pulls(gpio_num, pull_mode & AtomVMRP2040GPIOPullUp, pull_mode & AtomVMRP2040GPIOPullDown);
     return OK_ATOM;
@@ -117,23 +128,44 @@ static term nif_gpio_digital_write(Context *ctx, int argc, term argv[])
 {
     UNUSED(argc);
 
-    VALIDATE_VALUE(argv[0], term_is_integer);
-    int gpio_num = term_to_int(argv[0]);
+    term gpio_pin = argv[0];
     term level_term = argv[1];
 
     int level;
     if (term_is_integer(level_term)) {
         level = term_to_int32(level_term);
         if (UNLIKELY((level != 0) && (level != 1))) {
-            return ERROR_ATOM;
+            RAISE_ERROR(BADARG_ATOM);
         }
     } else {
         level = interop_atom_term_select_int(pin_level_table, level_term, ctx->global);
         if (UNLIKELY(level < 0)) {
-            return ERROR_ATOM;
+            RAISE_ERROR(BADARG_ATOM);
         }
     }
-    gpio_put(gpio_num, level);
+
+    uint gpio_num;
+    if (term_is_integer(gpio_pin)) {
+        gpio_num = gpio_pin;
+        gpio_put(gpio_num, level);
+#ifdef LIB_PICO_CYW43_ARCH
+    } else if (term_is_tuple(gpio_pin)) {
+        term gpio_bank_atom = term_get_tuple_element(gpio_pin, 0);
+        VALIDATE_VALUE(gpio_bank_atom, term_is_atom);
+        if (UNLIKELY(gpio_bank_atom != WL_ATOM)) {
+            RAISE_ERROR(BADARG_ATOM);
+        }
+        term pin_term = term_get_tuple_element(gpio_pin, 1);
+        VALIDATE_VALUE(pin_term, term_is_integer);
+        gpio_num = (uint) term_to_int32(pin_term);
+        if (UNLIKELY((gpio_num == -1) || (gpio_num > 1))) {
+            RAISE_ERROR(BADARG_ATOM);
+        }
+        cyw43_arch_gpio_put(gpio_num, level);
+#endif
+    } else {
+        RAISE_ERROR(BADARG_ATOM);
+    }
 
     return OK_ATOM;
 }
@@ -142,9 +174,31 @@ static term nif_gpio_digital_read(Context *ctx, int argc, term argv[])
 {
     UNUSED(argc);
 
-    VALIDATE_VALUE(argv[0], term_is_integer);
-    int gpio_num = term_to_int(argv[0]);
-    bool level = gpio_get(gpio_num);
+    term gpio_pin = argv[0];
+    uint gpio_num;
+    bool level;
+
+    if (term_is_integer(gpio_pin)) {
+        gpio_num = gpio_pin;
+        level = gpio_get(gpio_num);
+#ifdef LIB_PICO_CYW43_ARCH
+    } else if (term_is_tuple(gpio_pin)) {
+        term gpio_bank_atom = term_get_tuple_element(gpio_pin, 0);
+        VALIDATE_VALUE(gpio_bank_atom, term_is_atom);
+        if (UNLIKELY(gpio_bank_atom != WL_ATOM)) {
+            RAISE_ERROR(BADARG_ATOM);
+        }
+        term pin_term = term_get_tuple_element(gpio_pin, 1);
+        VALIDATE_VALUE(pin_term, term_is_integer);
+        gpio_num = (uint) term_to_int32(pin_term);
+        if (UNLIKELY((gpio_num != 2))) {
+            RAISE_ERROR(BADARG_ATOM);
+        }
+        level = cyw43_arch_gpio_get(gpio_num);
+#endif
+    } else {
+        RAISE_ERROR(BADARG_ATOM);
+    }
 
     return level ? globalcontext_make_atom(ctx->global, ATOM_STR("\x4", "high")) : globalcontext_make_atom(ctx->global, ATOM_STR("\x3", "low"));
 }