gpiod v2 support

Author: leventelist

src/CMakeLists.txt

@@ -104,6 +104,7 @@ list(APPEND direwolf_SOURCES
   dwgpsnmea.c
   dwgpsd.c
   mheard.c
+  gpio_common.c
   )
 
 if(LINUX)

src/audio.h

@@ -5,7 +5,7 @@
  *
  * Purpose:   	Interface to audio device commonly called a "sound card"
  *		for historical reasons.
- *		
+ *
  *---------------------------------------------------------------*/
 
 
@@ -19,13 +19,14 @@
 #include "direwolf.h"		/* for MAX_RADIO_CHANS and MAX_TOTAL_CHANS used throughout the application. */
 #include "ax25_pad.h"		/* for AX25_MAX_ADDR_LEN */
 #include "version.h"
-				
+#include "gpio_common.h"
+
 
 /*
- * PTT control. 
+ * PTT control.
  */
 
-enum ptt_method_e { 
+enum ptt_method_e {
 	PTT_METHOD_NONE,	/* VOX or no transmit. */
 	PTT_METHOD_SERIAL,	/* Serial port RTS or DTR. */
 	PTT_METHOD_GPIO,	/* General purpose I/O using sysfs, deprecated after 2020, Linux only. */
@@ -63,7 +64,7 @@ enum medium_e { MEDIUM_NONE = 0,	// Channel is not valid for use.
 
 
 typedef enum sanity_e { SANITY_APRS, SANITY_AX25, SANITY_NONE } sanity_t;
-			 
+
 
 struct audio_s {
 
@@ -276,7 +277,7 @@ struct audio_s {
 
 
 	/* Additional properties for transmit. */
-	
+
 	/* Originally we had control outputs only for PTT. */
 	/* In version 1.2, we generalize this to allow others such as DCD. */
 	/* In version 1.4 we add CON for connected to another station. */
@@ -288,8 +289,8 @@ struct audio_s {
 #define OCTYPE_CON 2
 
 #define NUM_OCTYPES 3		/* number of values above.   i.e. last value +1. */
-	
-	    struct {  		
+
+	    struct {
 
 	        ptt_method_t ptt_method; /* none, serial port, GPIO, LPT, HAMLIB, CM108. */
 
@@ -304,7 +305,7 @@ struct audio_s {
 					/* have a name like /dev/hidraw1 for Linux or */
 					/* \\?\hid#vid_0d8c&pid_0008&mi_03#8&39d3555&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030} */
 					/* for Windows.  Largest observed was 95 but add some extra to be safe. */
-			
+
 	        ptt_line_t ptt_line;	/* Control line when using serial port. PTT_LINE_RTS, PTT_LINE_DTR. */
 	        ptt_line_t ptt_line2;	/* Optional second one:  PTT_LINE_NONE when not used. */
 
@@ -330,6 +331,7 @@ struct audio_s {
 
 	        int ptt_invert;		/* Invert the output. */
 	        int ptt_invert2;	/* Invert the secondary output. */
+            gpio_num_t gpio_num;	/* Handle from libgpiod.  Valid only when ptt_method is PTT_METHOD_GPIOD. */
 
 #ifdef USE_HAMLIB
 

src/gpio_common.c

@@ -0,0 +1,176 @@
+#include <gpiod.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include <errno.h>
+#include <string.h>
+
+#include "gpio_common.h"
+
+#define GPIO_MAX_LINES 32
+#define GPIO_CONSUMER "FLDIGI"
+
+//Types
+typedef struct gpio_common {
+  struct gpiod_line_request *request;
+  unsigned int offset;
+  bool used;
+} gpio_common_t;
+
+// local variables
+
+static gpio_common_t gpio[GPIO_MAX_LINES];
+
+void gpio_common_init(void) {
+  fprintf(stderr, "Initializing GPIO common structure\n");
+  for (gpio_num_t i = 0; i < GPIO_MAX_LINES; i++) {
+    gpio[i].used = false;
+  }
+}
+
+
+gpio_num_t gpio_common_open_line(const char *chip_name, unsigned int line, bool active_low) {
+  gpio_num_t gpio_num;
+  int ret;
+
+  struct gpiod_request_config *req_cfg = NULL;
+	struct gpiod_line_settings *settings;
+	struct gpiod_line_config *line_cfg;
+	struct gpiod_chip *chip;
+
+  gpio_num = GPIO_COMMON_UNKNOWN;
+
+  if (chip_name == NULL) {
+    fprintf(stderr, "No chip name supplied.\n");
+    goto out;
+  }
+
+  fprintf(stderr, "Opening GPIO line %d on chip %s\n", line, chip_name);
+
+  // Get a free slot
+  for (gpio_num_t i = 0; i < GPIO_MAX_LINES; i++) {
+    if (gpio[i].used == false) {
+      gpio_num = i;
+      break;
+    }
+  }
+
+  if (gpio_num == GPIO_COMMON_UNKNOWN) {
+    fprintf(stderr, "Too many GPIOs open.\n");
+    goto out;
+  }
+
+  chip = gpiod_chip_open(chip_name);
+
+  if (chip == NULL) {
+    fprintf(stderr, "Failed to open GPIO chip %s\n", chip_name);
+    gpio_num = GPIO_COMMON_UNKNOWN;
+    goto out;
+  }
+
+  settings = gpiod_line_settings_new();
+
+  if (settings == NULL) {
+    fprintf(stderr, "Unable to allocate memory for line settings \n");
+    gpio_num = GPIO_COMMON_UNKNOWN;
+    goto close_chip;
+  }
+
+  gpiod_line_settings_set_direction(settings,
+					  GPIOD_LINE_DIRECTION_OUTPUT);
+	gpiod_line_settings_set_output_value(settings, 0);
+  gpiod_line_settings_set_active_low(settings, active_low);
+
+  line_cfg = gpiod_line_config_new();
+
+  if (!line_cfg) {
+    gpio_num = GPIO_COMMON_UNKNOWN;
+    goto free_settings;
+  }
+
+  ret = gpiod_line_config_add_line_settings(line_cfg, &line, 1,
+						  settings);
+	if (ret < 0) {
+    fprintf(stderr, "Failed to add line settings\n");
+    gpio_num = GPIO_COMMON_UNKNOWN;
+    goto free_line_config;
+  }
+
+  req_cfg = gpiod_request_config_new();
+	if (!req_cfg) {
+		goto free_line_config;
+  }
+
+  gpiod_request_config_set_consumer(req_cfg, "FLDIGI");
+
+  gpio[gpio_num].request = gpiod_chip_request_lines(chip, req_cfg, line_cfg);
+
+  if (gpio[gpio_num].request == NULL) {
+    fprintf(stderr, "Failed to request GPIO line %d\n", gpio_num);
+    gpio_num = GPIO_COMMON_UNKNOWN;
+    goto free_line_config;
+  } else {
+    gpio[gpio_num].used = true;
+    gpio[gpio_num].offset = line;
+  }
+
+free_line_config:
+	gpiod_line_config_free(line_cfg);
+
+free_settings:
+	gpiod_line_settings_free(settings);
+
+close_chip:
+	gpiod_chip_close(chip);
+
+
+out:
+
+  return gpio_num;
+}
+
+
+int gpio_common_release_line(gpio_num_t gpio_num) {
+  if (gpio_num >= GPIO_MAX_LINES) {
+    return -1;
+  }
+
+  if (gpio[gpio_num].request != NULL) {
+    gpiod_line_request_release(gpio[gpio_num].request);
+    gpio[gpio_num].request = NULL;
+  }
+
+  return 0;
+}
+
+
+int gpio_common_set(gpio_num_t gpio_num, bool val) {
+  if (gpio_num >= GPIO_MAX_LINES || gpio[gpio_num].request == NULL) {
+    return -1;
+  }
+  uint16_t gpiod_val;
+
+  if (val) {
+    gpiod_val = GPIOD_LINE_VALUE_ACTIVE;
+  } else {
+    gpiod_val = GPIOD_LINE_VALUE_INACTIVE;
+  }
+
+
+  int ret = gpiod_line_request_set_value(gpio[gpio_num].request, gpio[gpio_num].offset, gpiod_val);
+  if (ret < 0) {
+    fprintf(stderr, "Error setting line\n");
+    return -1;
+  }
+  return 0;
+}
+
+
+int gpio_common_close(void) {
+
+  for (gpio_num_t i = 0; i < GPIO_MAX_LINES; i++) {
+    gpio_common_release_line(i);
+  }
+
+  return 0;
+}

src/gpio_common.h

@@ -0,0 +1,25 @@
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <gpiod.h>
+#include <stdint.h>
+
+
+
+typedef uint16_t gpio_num_t;
+#define GPIO_COMMON_UNKNOWN           UINT16_MAX
+#define GPIO_COMMON_OK                0
+#define GPIO_COMMON_ERR               -1
+
+
+// Public functions
+
+void gpio_common_init(void);
+gpio_num_t gpio_common_open_line(const char *chip_name, unsigned int line, bool active_low);
+int gpio_common_close(void);
+int gpio_common_set(gpio_num_t gpio_num, bool val);
+
+#ifdef __cplusplus
+}
+#endif