use set_pin_mode() to set uart pinmux (#158)

Use set_pin_mode() to set pinmux for UART
RX and TX pins. This is similar effect as
running the config-pin utility.

Signed-off-by: Drew Fustini <drew@pdp7.com>

Author: pdp7

setup.py

@@ -54,6 +54,6 @@
       ext_modules      = [Extension('Adafruit_BBIO.GPIO', ['source/py_gpio.c', 'source/event_gpio.c', 'source/c_pinmux.c', 'source/constants.c', 'source/common.c'], **extension_args),
                           Extension('Adafruit_BBIO.PWM', ['source/py_pwm.c', 'source/c_pwm.c', 'source/c_pinmux.c', 'source/constants.c', 'source/common.c'], **extension_args),
                           Extension('Adafruit_BBIO.ADC', ['source/py_adc.c', 'source/c_adc.c', 'source/constants.c', 'source/common.c'], **extension_args),
-                          Extension('Adafruit_BBIO.SPI', ['source/spimodule.c', 'source/constants.c', 'source/common.c'], **extension_args),
-                          Extension('Adafruit_BBIO.UART', ['source/py_uart.c', 'source/c_uart.c', 'source/constants.c', 'source/common.c'], **extension_args)] )
+                          Extension('Adafruit_BBIO.SPI', ['source/spimodule.c', 'source/c_pinmux.c', 'source/constants.c', 'source/common.c'], **extension_args),
+                          Extension('Adafruit_BBIO.UART', ['source/py_uart.c', 'source/c_pinmux.c', 'source/c_uart.c', 'source/constants.c', 'source/common.c'], **extension_args)] )
 

source/common.c

@@ -263,14 +263,6 @@ pins_t table[] = {
   { NULL, NULL, 0, 0, 0 }
 };
 
-typedef struct uart_t { 
-    const char *name; 
-    const char *path;
-    const char *dt; 
-    const char *rx;
-    const char *tx;
-} uart_t;
-
 uart_t uart_table[] = {
   { "UART1", "/dev/ttyO1", "ADAFRUIT-UART1", "P9_26", "P9_24"},
   { "UART2", "/dev/ttyO2", "ADAFRUIT-UART2", "P9_22", "P9_21"},

source/common.h

@@ -64,6 +64,17 @@ typedef struct pwm_t {
   const char *key;  // Pin name eg P9_21
 } pwm_t;
 
+
+typedef struct uart_t {
+    const char *name;
+    const char *path;
+    const char *dt;
+    const char *rx;
+    const char *tx;
+} uart_t;
+
+extern uart_t uart_table[];
+
 extern int gpio_mode;
 extern int gpio_direction[120];
 

source/py_uart.c

@@ -25,6 +25,7 @@ SOFTWARE.
 #include "constants.h"
 #include "common.h"
 #include "c_uart.h"
+#include "c_pinmux.h"
 
 const char *valid_uarts[4] = {"UART1", "UART2", "UART4", "UART5"};
 
@@ -61,6 +62,29 @@ static PyObject *py_setup_uart(__attribute__ ((unused)) PyObject *self, PyObject
         return NULL;        
     }
 
+#ifdef BBBVERSION41
+    uart_t *p;
+    for (p = uart_table; p->name != NULL; ++p) {
+        if (strcmp(p->name, channel) == 0) {
+            err = set_pin_mode(p->rx, "uart");
+            //Check if set_pin_mode() returned no error
+            if (err != BBIO_OK) {
+                fprintf(stderr, "py_setup_uart(%s): set_pin_mode() failed for pin=%s", channel, p->rx);
+                PyErr_SetString(PyExc_ValueError, "Set pin mode failed for uart channel.");
+                return NULL;
+            }
+
+            err = set_pin_mode(p->tx, "uart");
+            //Check if set_pin_mode() returned no error
+            if (err != BBIO_OK) {
+                fprintf(stderr, "py_setup_uart(%s): set_pin_mode() failed for pin=%s", channel, p->tx);
+                PyErr_SetString(PyExc_ValueError, "Set pin mode failed for uart channel.");
+                return NULL;
+            }
+        }
+    }
+#endif
+
     Py_RETURN_NONE;
 }