Diff: targets/hal/TARGET_NXP/TARGET_LPC15XX/i2c_api.c

Revision:

117:e0a7df0a9a56

Parent:

103:9b881da47c92

Child:

182:242346c42295

--- a/targets/hal/TARGET_NXP/TARGET_LPC15XX/i2c_api.c	Tue Mar 11 17:15:06 2014 +0000
+++ b/targets/hal/TARGET_NXP/TARGET_LPC15XX/i2c_api.c	Wed Mar 12 10:30:07 2014 +0000
@@ -29,7 +29,7 @@
 
 // Wait until the Serial Interrupt (SI) is set
 static int i2c_wait_SI(i2c_t *obj) {
-    int timeout = 0;
+    volatile int timeout = 0;
     while (!(LPC_I2C0->STAT & (1 << 0))) {
         timeout++;
         if (timeout > 100000) return -1;
@@ -41,25 +41,21 @@
     LPC_I2C0->CFG |= (1 << 0);
 }
 
-static inline void i2c_power_enable(i2c_t *obj) {
+void i2c_init(i2c_t *obj, PinName sda, PinName scl) {
+    if ((sda != P0_23) | (scl != P0_22)) {
+        error("I2C pin mapping failed");
+    }
+    
     // Enables clock for I2C0
-    LPC_SYSCON->SYSAHBCLKCTRL1 |= (1<<13);
-//    LPC_SYSCON->PRESETCTRL1 &= ~(0x1<<13);
-    LPC_SYSCON->PRESETCTRL1 |= (0x1<<13);
-    LPC_SYSCON->PRESETCTRL1 &= ~(0x1 << 13);
+    LPC_SYSCON->SYSAHBCLKCTRL1 |= (1 << 13);
 
-}
+    LPC_SYSCON->PRESETCTRL1 |=  (1 << 13);
+    LPC_SYSCON->PRESETCTRL1 &= ~(1 << 13);
 
-void i2c_init(i2c_t *obj, PinName sda, PinName scl) {
-    
-    // ƒsƒ“’è‹`‚ÌŠm”F‚Ç‚¤‚µ‚悤c
-    
-    
-    // enable power
-    i2c_power_enable(obj);
     // pin enable
     LPC_SWM->PINENABLE1 &= ~(0x3 << 3);
-    // set default frequency at 100k
+
+    // set default frequency at 100kHz
     i2c_frequency(obj, 100000);
     i2c_interface_enable(obj);
 }
@@ -76,7 +72,7 @@
 }
 
 inline int i2c_stop(i2c_t *obj) {
-    int timeout = 0;
+    volatile int timeout = 0;
 
     LPC_I2C0->MSTCTL = (1 << 2) | (1 << 0);
     while ((LPC_I2C0->STAT & ((1 << 0) | (7 << 1))) != ((1 << 0) | (0 << 1))) {
@@ -107,14 +103,12 @@
         LPC_I2C0->MSTCTL = (1 << 0);
     
     // return the data
-    //return (I2C_DAT(obj) & 0xFF);
     return (LPC_I2C0->MSTDAT & 0xFF);
 }
 
 void i2c_frequency(i2c_t *obj, int hz) {
     // No peripheral clock divider on the M0
     uint32_t PCLK = SystemCoreClock;
-    
     uint32_t clkdiv = PCLK / (hz * 4) - 1;
     
     LPC_I2C0->DIV = clkdiv;
@@ -123,19 +117,15 @@
 
 int i2c_read(i2c_t *obj, int address, char *data, int length, int stop) {
     int count, status;
-    int timeout = 0;
     
     i2c_start(obj);
     
-    //status = i2c_do_write(obj, (address | 0x01), 1);
     LPC_I2C0->MSTDAT = (address | 0x01);
     LPC_I2C0->MSTCTL |= 0x20;
-    while (!(LPC_I2C0->STAT & (1 << 0))) {
-        timeout++;
-        if (timeout > 100000) return -1;
-    }
+    if (i2c_wait_SI(obj) == -1)
+        return -1;
+
     status = ((LPC_I2C0->STAT >> 1) & (0x07));
-    
     if (status != 0x01) {
         i2c_stop(obj);
         return I2C_ERROR_NO_SLAVE;
@@ -143,39 +133,27 @@
     
     // Read in all except last byte
     for (count = 0; count < (length - 1); count++) {
-        //int value = i2c_do_read(obj, 0);
-	    while (!(LPC_I2C0->STAT & (1 << 0))) {
-	        timeout++;
-	        if (timeout > 100000) return -1;
-	    }
-	    if (!0)
-	        LPC_I2C0->MSTCTL = (1 << 0);
-	    data[count] = (LPC_I2C0->MSTDAT & 0xFF);
-        //
-    	status = ((LPC_I2C0->STAT >> 1) & (0x07));
+        if (i2c_wait_SI(obj) == -1)
+            return -1;
+        LPC_I2C0->MSTCTL = (1 << 0);
+        data[count] = (LPC_I2C0->MSTDAT & 0xFF);
+        status = ((LPC_I2C0->STAT >> 1) & (0x07));
         if (status != 0x00) {
             i2c_stop(obj);
             return count;
         }
-        //data[count] = (char) value;
     }
     
     // read in last byte
-    //int value = i2c_do_read(obj, 1);
-    while (!(LPC_I2C0->STAT & (1 << 0))) {
-        timeout++;
-        if (timeout > 100000) return -1;
-    }
+    if (i2c_wait_SI(obj) == -1)
+        return -1;
+
     data[count] = (LPC_I2C0->MSTDAT & 0xFF);
-    //
     status = i2c_status(obj);
     if (status != 0x01) {
         i2c_stop(obj);
         return length - 1;
     }
-    
-    //data[count] = (char) value;
-    
     // If not repeated start, send stop.
     if (stop) {
         i2c_stop(obj);
@@ -188,35 +166,27 @@
 
 int i2c_write(i2c_t *obj, int address, const char *data, int length, int stop) {
     int i, status;
-    int timeout = 0;
     
     i2c_start(obj);
     
-    //status = i2c_do_write(obj, (address & 0xFE), 1);
     LPC_I2C0->MSTDAT = (address & 0xFE);
     LPC_I2C0->MSTCTL |= 0x20;
-    // wait and return status
-    while (!(LPC_I2C0->STAT & (1 << 0))) {
-        timeout++;
-        if (timeout > 100000) return -1;
-    }
+    if (i2c_wait_SI(obj) == -1)
+        return -1;
+
     status = ((LPC_I2C0->STAT >> 1) & (0x07));
-        
     if (status != 0x02) {
         i2c_stop(obj);
         return I2C_ERROR_NO_SLAVE;
     }
     
     for (i=0; i<length; i++) {
-        //status = i2c_do_write(obj, data[i], 0);
         LPC_I2C0->MSTDAT = data[i];
         LPC_I2C0->MSTCTL = (1 << 0);
-        // wait and return status
-	    while (!(LPC_I2C0->STAT & (1 << 0))) {
-	        timeout++;
-	        if (timeout > 100000) return -1;
-	    }
-    	status = ((LPC_I2C0->STAT >> 1) & (0x07));
+        if (i2c_wait_SI(obj) == -1)
+            return -1;
+
+        status = ((LPC_I2C0->STAT >> 1) & (0x07));
         if (status != 0x02) {
             i2c_stop(obj);
             return i;
@@ -242,17 +212,9 @@
 }
 
 int i2c_byte_write(i2c_t *obj, int data) {
-    int ack;
-    int status = i2c_do_write(obj, (data & 0xFF), 0);
-    
-    switch(status) {
-        case 2:
-            ack = 1;
-            break;
-        default:
-            ack = 0;
-            break;
+    if (i2c_do_write(obj, (data & 0xFF), 0) == 2) {
+        return 1;
+    } else {
+        return 0;
     }
-
-    return ack;
 }