Refactor I2C functions to return w_status_t for improved error handling and type safety

Author: taisirhassan

include/i2c.h

@@ -1,21 +1,21 @@
 #ifndef ROCKETLIB_I2C_H
 #define ROCKETLIB_I2C_H
 
-#include <stdbool.h>
+#include "common.h"
 #include <stdint.h>
 
 /* Initialize I2C Controller
    I2C Frequency = (100 kHz) / (2 ^ clkdiv)
    Max frequency clkdiv = b000, 100kHz
    Min frequency clkdiv = b111, 781.25 Hz
 */
-void i2c_init(uint8_t clkdiv);
+w_status_t i2c_init(uint8_t clkdiv);
 
-bool i2c_write_data(uint8_t address, const uint8_t *data, uint8_t len);
-bool i2c_read_data(uint8_t address, uint8_t *data, uint8_t len);
-bool i2c_write_reg8(uint8_t address, uint8_t reg, uint8_t val);
-bool i2c_write_reg16(uint8_t address, uint8_t reg, uint16_t val);
-bool i2c_read_reg8(uint8_t address, uint8_t reg, uint8_t *value);
-bool i2c_read_reg16(uint8_t address, uint8_t reg, uint16_t *value);
+w_status_t i2c_write_data(uint8_t address, const uint8_t *data, uint8_t len);
+w_status_t i2c_read_data(uint8_t address, uint8_t *data, uint8_t len);
+w_status_t i2c_write_reg8(uint8_t address, uint8_t reg, uint8_t val);
+w_status_t i2c_write_reg16(uint8_t address, uint8_t reg, uint16_t val);
+w_status_t i2c_read_reg8(uint8_t address, uint8_t reg, uint8_t *value);
+w_status_t i2c_read_reg16(uint8_t address, uint8_t reg, uint16_t *value);
 
 #endif

pic18f26k83/i2c.c

@@ -6,7 +6,7 @@
 #define I2C_POLL_TIMEOUT 2000
 #endif
 
-void i2c_init(uint8_t clkdiv) {
+w_status_t i2c_init(uint8_t clkdiv) {
     // CSTR Enable clocking; S Cleared by hardware after Start; MODE 7-bit address; EN enabled; RSEN
     // disabled;
     I2C1CON0 = 0x84;
@@ -23,9 +23,11 @@ void i2c_init(uint8_t clkdiv) {
     I2C1CLK = 0x04;
     I2C1PIR = 0; //    ;Clear all the error flags
     I2C1ERR = 0;
+
+    return W_SUCCESS;
 }
 
-static bool i2c_write(uint8_t address, const uint8_t *data, uint8_t len) {
+static w_status_t i2c_write(uint8_t address, const uint8_t *data, uint8_t len) {
     I2C1ADB1 = (uint8_t)(address << 1);
     I2C1CNT = len;
     I2C1PIRbits.PCIF = 0;
@@ -38,30 +40,34 @@ static bool i2c_write(uint8_t address, const uint8_t *data, uint8_t len) {
         timeout = 0;
         while (!I2C1STAT1bits.TXBE && !I2C1ERRbits.NACKIF) {
             if (timeout >= I2C_POLL_TIMEOUT) {
-                break;
+                return W_IO_TIMEOUT;
             }
             timeout++;
         }
         if (I2C1ERRbits.NACKIF) {
-            break;
+            return W_IO_ERROR;
         }
     }
 
     timeout = 0;
     while (!I2C1PIRbits.PCIF) {
         if (timeout >= I2C_POLL_TIMEOUT) {
-            break;
+            return W_IO_TIMEOUT;
         }
         timeout++;
     }
 
     I2C1PIRbits.PCIF = 0;
     I2C1STAT1bits.CLRBF = 1;
 
-    return (I2C1ERR & 0x70) != 0;
+    if ((I2C1ERR & 0x70) != 0) {
+        return W_IO_ERROR;
+    }
+
+    return W_SUCCESS;
 }
 
-static bool i2c_read(uint8_t address, uint8_t *data, uint8_t len) {
+static w_status_t i2c_read(uint8_t address, uint8_t *data, uint8_t len) {
     I2C1ADB1 = (uint8_t)((address << 1) | 1);
     I2C1CNT = len;
     I2C1PIRbits.PCIF = 0;
@@ -73,72 +79,76 @@ static bool i2c_read(uint8_t address, uint8_t *data, uint8_t len) {
         timeout = 0;
         while (!I2C1STAT1bits.RXBF && !I2C1ERRbits.NACKIF) {
             if (timeout >= I2C_POLL_TIMEOUT) {
-                break;
+                return W_IO_TIMEOUT;
             }
             timeout++;
         }
         if (I2C1ERRbits.NACKIF) {
-            break;
+            return W_IO_ERROR;
         }
         *data++ = I2C1RXB;
     }
 
     timeout = 0;
     while (!I2C1PIRbits.PCIF) {
         if (timeout >= I2C_POLL_TIMEOUT) {
-            break;
+            return W_IO_TIMEOUT;
         }
         timeout++;
     }
     I2C1PIRbits.PCIF = 0;
     I2C1STAT1bits.CLRBF = 1;
 
-    return (I2C1ERR & 0x70) != 0;
+    if ((I2C1ERR & 0x70) != 0) {
+        return W_IO_ERROR;
+    }
+
+    return W_SUCCESS;
 }
 
-bool i2c_write_data(uint8_t address, const uint8_t *data, uint8_t len) {
+w_status_t i2c_write_data(uint8_t address, const uint8_t *data, uint8_t len) {
     return i2c_write(address, data, len);
 }
 
-bool i2c_read_data(uint8_t address, uint8_t *data, uint8_t len) {
+w_status_t i2c_read_data(uint8_t address, uint8_t *data, uint8_t len) {
     return i2c_read(address, data, len);
 }
 
-bool i2c_write_reg8(uint8_t address, uint8_t reg, uint8_t val) {
+w_status_t i2c_write_reg8(uint8_t address, uint8_t reg, uint8_t val) {
     uint8_t data[2] = {reg, val};
     return i2c_write(address, data, 2);
 }
 
-bool i2c_write_reg16(uint8_t address, uint8_t reg, uint16_t val) {
+w_status_t i2c_write_reg16(uint8_t address, uint8_t reg, uint16_t val) {
     uint8_t data[3] = {reg, (uint8_t)(val >> 8), (uint8_t)val};
     return i2c_write(address, data, 3);
 }
 
-bool i2c_read_reg8(uint8_t address, uint8_t reg, uint8_t *value) {
-    bool success = i2c_write(address, &reg, 1);
-    if (!success) {
-        return false;
+w_status_t i2c_read_reg8(uint8_t address, uint8_t reg, uint8_t *value) {
+    w_status_t status = i2c_write(address, &reg, 1);
+    if (status != W_SUCCESS) {
+        return W_IO_ERROR;
     }
 
     uint8_t data;
-    success = i2c_read(address, &data, 1);
-    if (!success) {
-        return false;
+    status = i2c_read(address, &data, 1);
+    if (status != W_SUCCESS) {
+        return W_IO_ERROR;
     }
     *value = data;
-    return true;
+    return W_SUCCESS;
 }
 
-bool i2c_read_reg16(uint8_t address, uint8_t reg, uint16_t *value) {
-    bool success = i2c_write(address, &reg, 1);
-    if (!success) {
-        return false;
+w_status_t i2c_read_reg16(uint8_t address, uint8_t reg, uint16_t *value) {
+    w_status_t status = i2c_write(address, &reg, 1);
+    if (status != W_SUCCESS) {
+        return W_IO_ERROR;
     }
     uint8_t data[2];
-    success = i2c_read(address, data, 2);
-    if (!success) {
-        return false;
+    status = i2c_read(address, data, 2);
+    if (status != W_SUCCESS) {
+        return W_IO_ERROR;
     }
     *value = (uint16_t)(data[0]) << 8 | data[1];
-    return true;
+    return W_SUCCESS;
 }