Suffix the nif functions to allow an extra layer of guards and erlang…

… code This makes it possible to for example accept atoms for input/output further on instead of solely relying on macros which makes interactive use a bit easier.
klajo · Jul 27, 2012 · f516058 · f516058
1 parent 627fe97
commit f516058
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Showing 2 changed files with 39 additions and 22 deletions.
diff --git a/c_src/wpi.c b/c_src/wpi.c
@@ -24,7 +24,7 @@ load(ErlNifEnv* env, void** priv_data, ERL_NIF_TERM load_info)
 }
 
 static ERL_NIF_TERM
-pin_mode(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+pin_mode_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 {
     int pin, mode;
     if (!enif_get_int(env, argv[0], &pin))
@@ -40,7 +40,7 @@ pin_mode(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 }
 
 static ERL_NIF_TERM
-digital_write(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+digital_write_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 {
     int pin, value;
     if (!enif_get_int(env, argv[0], &pin))
@@ -56,7 +56,7 @@ digital_write(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 }
 
 static ERL_NIF_TERM
-pwm_write(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+pwm_write_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 {
     int pin, value;
     if (!enif_get_int(env, argv[0], &pin))
@@ -72,7 +72,7 @@ pwm_write(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 }
 
 static ERL_NIF_TERM
-digital_read(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+digital_read_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 {
     int pin, value;
     if (!enif_get_int(env, argv[0], &pin))
@@ -84,7 +84,7 @@ digital_read(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 }
 
 static ERL_NIF_TERM
-pull_up_dn_control(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+pull_up_dn_control_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 {
     int pin, mode;
     if (!enif_get_int(env, argv[0], &pin))
@@ -101,11 +101,11 @@ pull_up_dn_control(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 
 static ErlNifFunc nif_funcs[] =
     {
-        {"pin_mode",           2, pin_mode},
-        {"digital_write",      2, digital_write},
-        {"pwm_write",          2, pwm_write},
-        {"digital_read",       1, digital_read},
-        {"pull_up_dn_control", 2, pull_up_dn_control}
+        {"pin_mode_nif",           2, pin_mode_nif},
+        {"digital_write_nif",      2, digital_write_nif},
+        {"pwm_write_nif",          2, pwm_write_nif},
+        {"digital_read_nif",       1, digital_read_nif},
+        {"pull_up_dn_control_nif", 2, pull_up_dn_control_nif}
     };
 
 ERL_NIF_INIT(wpi, nif_funcs, load, NULL, NULL, NULL)
diff --git a/src/wpi.erl b/src/wpi.erl
@@ -32,28 +32,45 @@
 -type wpi_pin_mode()      :: 0..2.    % WPI_INPUT|WPI_OUTPUT|WPI_PWM_OUTPUT
 -type wpi_pin_number()    :: integer().
 -type wpi_digital_value() :: 0..1.    % WPI_LOW|WPI_HIGH
--type wpi_pwm_value()     :: 0..1024.
--type wpi_pud_mode()      :: 0..2.    % WPI_PUD_OFF|WPI_PUD_DOWN|WPI_PUD_DOWN
+-type wpi_pwm_value()     :: 0..1023.
+-type wpi_pud_mode()      :: 0..2.    % WPI_PUD_OFF|WPI_PUD_DOWN|WPI_PUD_UP
 
 on_load() ->
     ok = erlang:load_nif(filename:join(code:priv_dir(wpi), "./wpi_drv"), 0).
 
 -spec pin_mode(wpi_pin_number(), wpi_pin_mode()) -> ok.
-pin_mode(_Pin, _Mode) ->
-    ?nif_stub.
+pin_mode(Pin, Mode) when is_integer(Pin),
+                         (Mode == ?WPI_INPUT orelse
+                          Mode == ?WPI_OUTPUT orelse
+                          Mode == ?WPI_PWM_OUTPUT) ->
+    pin_mode_nif(Pin, Mode).
 
 -spec digital_write(wpi_pin_number(), wpi_digital_value()) -> ok.
-digital_write(_Pin, _Value) ->
-    ?nif_stub.
+digital_write(Pin, Value) when is_integer(Pin),
+                               (Value == ?WPI_LOW orelse
+                                Value == ?WPI_HIGH) ->
+    digital_write_nif(Pin, Value).
 
 -spec pwm_write(wpi_pin_number(), wpi_pwm_value()) -> ok.
-pwm_write(_Pin, _Value) ->
-    ?nif_stub.
+pwm_write(Pin, Value) when is_integer(Pin),
+                           is_integer(Value),
+                           Value >= 0,
+                           Value < 1024 ->
+    pwm_write_nif(Pin, Value).
 
 -spec digital_read(wpi_pin_number()) -> wpi_digital_value().
-digital_read(_Pin) ->
-    ?nif_stub.
+digital_read(Pin) when is_integer(Pin) ->
+    digital_read_nif(Pin).
 
 -spec pull_up_dn_control(wpi_pin_number(), wpi_pud_mode()) -> ok.
-pull_up_dn_control(_Pin, _Mode) ->
-    ?nif_stub.
+pull_up_dn_control(Pin, Mode) when is_integer(Pin),
+                                   (Mode == ?WPI_PUD_OFF orelse
+                                    Mode == ?WPI_PUD_DOWN orelse
+                                    Mode == ?WPI_PUD_UP) ->
+    pull_up_dn_control_nif(Pin, Mode).
+
+pin_mode_nif(_Pin, _Mode)           -> ?nif_stub.
+digital_write_nif(_Pin, _Value)     -> ?nif_stub.
+pwm_write_nif(_Pin, _Value)         -> ?nif_stub.
+digital_read_nif(_Pin)              -> ?nif_stub.
+pull_up_dn_control_nif(_Pin, _Mode) -> ?nif_stub.