Create README.md

Signed-off-by: Michel-FK <michel.stempin@funkey-project.com>

.gitignore

@@ -4,3 +4,4 @@
 ###################
 *.o
 funkey_gpio_management
+termfix

README.md

@@ -0,0 +1,4 @@
+# FunKey-GPIO-Mapping
+Embedded Linux OS GPIO mapping daemon for the FunKey S retro-gaming console
+
+**Note**: This repository is archived and read-only, as this functionality is now handled by [fkgpiod](https://github.com/FunKey-Project/fkgpiod).

driver_pcal6416a.c

@@ -26,11 +26,26 @@
 	#define DEBUG_PRINTF(...)
 #endif
 
+/****************************************************************
+ * Structures
+ ****************************************************************/
+
+typedef struct {
+    unsigned int address;
+    char *name;
+} i2c_expander_t;
+
 /****************************************************************
  * Static variables
  ****************************************************************/
 static int fd_i2c_expander;
+static unsigned int i2c_expander_addr;
 static char i2c0_sysfs_filename[] = "/dev/i2c-0";
+static i2c_expander_t i2c_chip[] = {
+    {PCAL9539A_I2C_ADDR, "PCAL9539A"},
+    {PCAL6416A_I2C_ADDR, "PCAL6416A"},
+    {0, NULL}
+};
 
 /****************************************************************
  * Static functions
@@ -40,20 +55,32 @@ static char i2c0_sysfs_filename[] = "/dev/i2c-0";
  * Public functions
  ****************************************************************/
 bool pcal6416a_init(void) {
+    int i;
+
     if ((fd_i2c_expander = open(i2c0_sysfs_filename,O_RDWR)) < 0) {
         printf("Failed to open the I2C bus %s", i2c0_sysfs_filename);
         // ERROR HANDLING; you can check errno to see what went wrong 
         return false;
     }
+    
+    /// Probing known I2C GPIO expander chips
+    for (i = 0, i2c_expander_addr = 0; i2c_chip[i].address; i++) {
 
-    if (ioctl(fd_i2c_expander,I2C_SLAVE,PCAL6416A_I2C_ADDR) < 0) {
-        printf("In pcal6416a_init - Failed to acquire bus access and/or talk to slave.\n");
-        // ERROR HANDLING; you can check errno to see what went wrong 
-        if (ioctl(fd_i2c_expander, I2C_SLAVE_FORCE, PCAL6416A_I2C_ADDR) < 0) {
-            printf("In pcal6416a_init - Failed to acquire FORCED bus access and/or talk to slave.\n");
-            // ERROR HANDLING; you can check errno to see what went wrong 
-            return false;
-        }
+        if (ioctl(fd_i2c_expander, I2C_SLAVE_FORCE, i2c_chip[i]) < 0 ||
+	    pcal6416a_read_mask_interrupts() < 0) {
+            DEBUG_PRINTF("In %s - Failed to acquire bus access and/or talk to slave %s at address 0x%02X.\n",
+		   __func__, i2c_chip[i].name, i2c_chip[i].address);
+    	} else {
+    	    DEBUG_PRINTF("Found I2C gpio expander chip %s at address 0x%02X\n",
+    	        i2c_chip[i].name, i2c_chip[i].address);
+    	    i2c_expander_addr = i2c_chip[i].address;
+            break;
+    	}
+    }
+
+    /// GPIO expander chip found?
+    if(!i2c_expander_addr){
+        printf("In %s - Failed to acquire bus access and/or talk to slave, exit\n", __func__);
         return false;
     }
 
@@ -101,4 +128,4 @@ int pcal6416a_read_mask_active_GPIOs(void){
 	val = 0xFFFF-val;
  	DEBUG_PRINTF("READ PCAL6416A_INPUT (active GPIOs) :  0x%04X\n",val);
  	return (int) val;
-}
+}

driver_pcal6416a.h

@@ -12,6 +12,7 @@
  ****************************************************************/
 // Chip physical address
 #define PCAL6416A_I2C_ADDR			0x20
+#define PCAL9539A_I2C_ADDR			0x76
 
 // Chip registers adresses
 #define PCAL6416A_INPUT				0x00 /* Input port [RO] */

gpio_mapping.c

@@ -491,4 +491,3 @@ int listen_gpios_interrupts(void)
 
 	return 0;
 }
-