Add GPIO reset support for the RaspberryPi.

osint.h

@@ -2,7 +2,7 @@
  * @file osint.h
  *
  * Serial I/O functions used by PLoadLib.c
-  *
+ *
  * Copyright (c) 2009 by John Steven Denson
  * Modified in 2011 by David Michael Betz
  *
@@ -35,8 +35,11 @@
 /* serial i/o definitions */
 #define SERIAL_TIMEOUT  -1
 
+/* Method of issuing reset to the Propeller chip. */
+typedef enum {RESET_WITH_RTS, RESET_WITH_DTR, RESET_WITH_GPIO} reset_method_t;
+
 /* serial i/o routines */
-void serial_use_rts_for_reset(int use_rts);
+int use_reset_method(char* method);
 int serial_find(const char* prefix, int (*check)(const char* port, void* data), void* data);
 int serial_init(const char *port, unsigned long baud);
 int serial_baud(unsigned long baud);

osint_linux.c

@@ -44,17 +44,37 @@
 #include <signal.h>
 
 #include "osint.h"
+#ifdef RASPBERRY_PI
+#include "gpio_sysfs.h"
+#endif
 
 typedef int HANDLE;
 static HANDLE hSerial = -1;
 static struct termios old_sparm;
+static int continue_terminal = 1;
 
-/* normally we use DTR for reset but setting this variable to non-zero will use RTS instead */
+/* Normally we use DTR for reset */
-static int use_rts_for_reset = 0;
+static reset_method_t reset_method = RESET_WITH_DTR;
 
-void serial_use_rts_for_reset(int use_rts)
+int use_reset_method(char* method)
 {
-    use_rts_for_reset = use_rts;
+    if (strcasecmp(method, "dtr") == 0)
+        reset_method = RESET_WITH_DTR;
+    else if (strcasecmp(method, "rts") == 0)
+       reset_method = RESET_WITH_RTS;
+#ifdef RASPBERRY_PI
+    else if (strcasecmp(method, "gpio") == 0)
+    {
+        reset_method = RESET_WITH_GPIO;
+        gpio_export(17);
+        gpio_write(17, 0);
+        gpio_direction(17, 1);
+    }
+#endif
+    else {
+        return -1;
+    }
+    return 0;
 }
 
 static void chk(char *fun, int sts)
@@ -89,19 +109,19 @@ int serial_find(const char* prefix, int (*check)(const char* port, void* data),
 
 static void sigint_handler(int signum)
 {
-    serial_done();
+        serial_done();
-    exit(1);
+        continue_terminal = 0;
 }
 
 /**
  * open serial port
  * @param port - COMn port name
- * @param baud - baud rate
+ * @returns hSerial - file handle to serial port
- * @returns 1 for success and 0 for failure
  */
 int serial_init(const char* port, unsigned long baud)
 {
     struct termios sparm;
+    int tbaud = 0;
 
     /* open the port */
 #ifdef MACOSX
@@ -124,7 +144,7 @@ int serial_init(const char* port, unsigned long baud)
     }
 
     fcntl(hSerial, F_SETFL, 0);
-    
+
     /* set the baud rate */
     if (!serial_baud(baud)) {
         close(hSerial);
@@ -137,9 +157,10 @@ int serial_init(const char* port, unsigned long baud)
     
     /* set raw input */
 #ifdef MACOSX
-    cfmakeraw(&sparm);
+        cfmakeraw(&sparm);
-    sparm.c_cc[VTIME] = 0;
+        sparm.c_cc[VTIME] = 0;
-    sparm.c_cc[VMIN] = 1;
+        sparm.c_cc[VMIN] = 1;
+        chk("cfsetspeed", cfsetspeed(&sparm, tbaud));
 #else
     memset(&sparm, 0, sizeof(sparm));
     sparm.c_cflag     = CS8 | CLOCAL | CREAD;
@@ -149,6 +170,8 @@ int serial_init(const char* port, unsigned long baud)
     sparm.c_iflag     = IGNPAR | IGNBRK;
     sparm.c_cc[VTIME] = 0;
     sparm.c_cc[VMIN] = 1;
+    chk("cfsetispeed", cfsetispeed(&sparm, tbaud));
+    chk("cfsetospeed", cfsetospeed(&sparm, tbaud));
 #endif
 
     /* set the options */
@@ -266,6 +289,12 @@ void serial_done(void)
         close(hSerial);
         hSerial = -1;
     }
+#ifdef RASPBERRY_PI
+    if (reset_method == RESET_WITH_GPIO)
+    {
+        gpio_unexport(17);
+    }
+#endif
 }
 
 /**
@@ -336,16 +365,72 @@ int rx_timeout(uint8_t* buff, int n, int timeout)
 }
 
 /**
- * hwreset ... resets Propeller hardware using DTR or RTS
+ * assert_reset ... Asserts the Propellers reset signal via DTR, RTS or GPIO pin.
- * @param sparm - pointer to DCB serial control struct
+ * @returns void
+ */
+static void assert_reset(void)
+{
+    int cmd;
+
+    switch (reset_method)
+    {
+    case RESET_WITH_DTR:
+        cmd = TIOCM_DTR;
+        ioctl(hSerial, TIOCMBIS, &cmd); /* assert bit */
+        break;
+    case RESET_WITH_RTS:
+        cmd = TIOCM_RTS;
+        ioctl(hSerial, TIOCMBIS, &cmd); /* assert bit */
+        break;
+#ifdef RASPBERRY_PI
+    case RESET_WITH_GPIO:
+        gpio_write(17, 1);
+        break;
+#endif
+    default:
+        // should be reached
+        break;
+    }
+}
+
+/**
+ * deassert_reset ... Deasserts the Propellers reset signal via DTR, RTS or GPIO pin.
+ * @returns void
+ */
+static void deassert_reset(void)
+{
+    int cmd;
+
+    switch (reset_method)
+    {
+    case RESET_WITH_DTR:
+        cmd = TIOCM_DTR;
+        ioctl(hSerial, TIOCMBIC, &cmd); /* assert bit */
+        break;
+    case RESET_WITH_RTS:
+        cmd = TIOCM_RTS;
+        ioctl(hSerial, TIOCMBIC, &cmd); /* assert bit */
+        break;
+#ifdef RASPBERRY_PI
+    case RESET_WITH_GPIO:
+        gpio_write(17, 0);
+        break;
+#endif
+    default:
+        // should be reached
+        break;
+    }
+}
+
+/**
+ * hwreset ... resets Propeller hardware.
  * @returns void
  */
 void hwreset(void)
 {
-    int cmd = use_rts_for_reset ? TIOCM_RTS : TIOCM_DTR;
+    assert_reset();
-    ioctl(hSerial, TIOCMBIS, &cmd); /* assert bit */
     msleep(10);
-    ioctl(hSerial, TIOCMBIC, &cmd); /* clear bit */
+    deassert_reset();
     msleep(90);
     tcflush(hSerial, TCIFLUSH);
 }
@@ -377,18 +462,17 @@ void msleep(int ms)
 void terminal_mode(int check_for_exit, int pst_mode)
 {
     struct termios oldt, newt;
-    char buf[128], realbuf[256]; // double in case buf is filled with \r in PST mode
+    char buf[128], realbuf[256];
     ssize_t cnt;
     fd_set set;
     int exit_char = 0xdead; /* not a valid character */
     int sawexit_char = 0;
     int sawexit_valid = 0; 
     int exitcode = 0;
-    int continue_terminal = 1;
 
     tcgetattr(STDIN_FILENO, &oldt);
     newt = oldt;
-    newt.c_lflag &= ~(ICANON | ECHO | ISIG);
+    newt.c_lflag &= ~(ICANON | ECHO);
     newt.c_iflag &= ~(ICRNL | INLCR);
     newt.c_oflag &= ~OPOST;
     tcsetattr(STDIN_FILENO, TCSANOW, &newt);

p1load.c

@@ -156,6 +156,10 @@ int main(int argc, char *argv[])
         }
     }
     
+#ifdef RASPBERRY_PI
+    use_reset_method("gpio");
+#endif
+
     switch (InitPort(PORT_PREFIX, port, baudRate, verbose, actualPort)) {
     case CHECK_PORT_OK:
         printf("Found propeller version %d on %s\n", version, actualPort);