MIMXRT1050_EVK: Update the I2C driver

1. Remove the repeated_start flag and code as this is not needed
   for the LPI2C module
2. Enable the SION bit on the I2C pins
3. Enable 22K Pullup option of the I2C pins
4. Update the 0 byte write implementation to ensure the START
   command gets flushed out of the FIFO

Signed-off-by: Mahesh Mahadevan <[email protected]>

Author: mmahadevan108

targets/TARGET_NXP/TARGET_MCUXpresso_MCUS/TARGET_IMX/i2c_api.c

@@ -37,7 +37,7 @@ void i2c_init(i2c_t *obj, PinName sda, PinName scl)
     uint32_t i2c_sda = pinmap_peripheral(sda, PinMap_I2C_SDA);
     uint32_t i2c_scl = pinmap_peripheral(scl, PinMap_I2C_SCL);
     obj->instance = pinmap_merge(i2c_sda, i2c_scl);
-    obj->next_repeated_start = 0;
+
     MBED_ASSERT((int)obj->instance != NC);
 
     lpi2c_master_config_t master_config;
@@ -50,6 +50,9 @@ void i2c_init(i2c_t *obj, PinName sda, PinName scl)
     pinmap_pinout(sda, PinMap_I2C_SDA);
     pinmap_pinout(scl, PinMap_I2C_SCL);
 
+    pin_mode(sda, PullUp_22K);
+    pin_mode(scl, PullUp_22K);
+
     pin_mode_opendrain(sda, true);
     pin_mode_opendrain(scl, true);
 }
@@ -65,7 +68,6 @@ int i2c_start(i2c_t *obj)
 
 int i2c_stop(i2c_t *obj)
 {
-    obj->next_repeated_start = 0;
     if (LPI2C_MasterStop(i2c_addrs[obj->instance]) != kStatus_Success) {
         return 1;
     }
@@ -78,7 +80,7 @@ void i2c_frequency(i2c_t *obj, int hz)
     uint32_t busClock;
 
     busClock = i2c_get_clock();
-    LPI2C_MasterSetBaudRate(i2c_addrs[obj->instance], hz, busClock);
+    LPI2C_MasterSetBaudRate(i2c_addrs[obj->instance], busClock, hz);
 }
 
 int i2c_read(i2c_t *obj, int address, char *data, int length, int stop)
@@ -92,13 +94,9 @@ int i2c_read(i2c_t *obj, int address, char *data, int length, int stop)
     master_xfer.direction = kLPI2C_Read;
     master_xfer.data = (uint8_t *)data;
     master_xfer.dataSize = length;
-    if (obj->next_repeated_start) {
-        master_xfer.flags |= kLPI2C_TransferRepeatedStartFlag;
-    }
     if (!stop) {
         master_xfer.flags |= kLPI2C_TransferNoStopFlag;
     }
-    obj->next_repeated_start = master_xfer.flags & kLPI2C_TransferNoStopFlag ? 1 : 0;
 
     /* The below function will issue a STOP signal at the end of the transfer.
      * This is required by the hardware in order to receive the last byte
@@ -120,11 +118,20 @@ int i2c_write(i2c_t *obj, int address, const char *data, int length, int stop)
             return I2C_ERROR_NO_SLAVE;
         }
 
+        /* Wait till START has been flushed out of the FIFO */
+        while (!(base->MSR & kLPI2C_MasterBusBusyFlag)) {
+        }
+
+        /* Send the STOP signal */
+        base->MTDR = LPI2C_MTDR_CMD(0x2U);
+
+        /* Wait till STOP has been sent successfully */
+        while (!(base->MSR & kLPI2C_MasterStopDetectFlag)) {
+        }
+
         if (base->MSR & kLPI2C_MasterNackDetectFlag) {
-            i2c_stop(obj);
             return I2C_ERROR_NO_SLAVE;
         } else {
-            i2c_stop(obj);
             return length;
         }
     }
@@ -134,13 +141,9 @@ int i2c_write(i2c_t *obj, int address, const char *data, int length, int stop)
     master_xfer.direction = kLPI2C_Write;
     master_xfer.data = (uint8_t *)data;
     master_xfer.dataSize = length;
-    if (obj->next_repeated_start) {
-        master_xfer.flags |= kLPI2C_TransferRepeatedStartFlag;
-    }
     if (!stop) {
         master_xfer.flags |= kLPI2C_TransferNoStopFlag;
     }
-    obj->next_repeated_start = master_xfer.flags & kLPI2C_TransferNoStopFlag ? 1 : 0;
 
     if (LPI2C_MasterTransferBlocking(base, &master_xfer) != kStatus_Success) {
         return I2C_ERROR_NO_SLAVE;

targets/TARGET_NXP/TARGET_MCUXpresso_MCUS/TARGET_IMX/objects.h

@@ -50,7 +50,6 @@ struct analogin_s {
 
 struct i2c_s {
     uint32_t instance;
-    uint8_t next_repeated_start;
 };
 
 struct spi_s {

targets/TARGET_NXP/TARGET_MCUXpresso_MCUS/TARGET_IMX/pinmap.c

@@ -54,7 +54,8 @@ void pin_function(PinName pin, int function)
     }
 
     /* Write to the mux register */
-    *((volatile uint32_t *)muxregister) = IOMUXC_SW_MUX_CTL_PAD_MUX_MODE(function);
+    *((volatile uint32_t *)muxregister) = IOMUXC_SW_MUX_CTL_PAD_MUX_MODE(function) |
+                                          IOMUXC_SW_MUX_CTL_PAD_SION((function >> SION_BIT_SHIFT) & 0x1);
 
     /* If required write to the input daisy register */
     daisyregister = (function >> DAISY_REG_SHIFT) & 0xFFF;

targets/TARGET_NXP/TARGET_MCUXpresso_MCUS/TARGET_MIMXRT1050/TARGET_EVK/PeripheralNames.h

@@ -37,6 +37,7 @@ typedef enum {
 #define STDIO_UART_RX     USBRX
 #define STDIO_UART        UART_1
 
+#define SION_BIT_SHIFT        (3)
 #define DAISY_REG_SHIFT       (4)
 #define DAISY_REG_VALUE_SHIFT (16)
 

targets/TARGET_NXP/TARGET_MCUXpresso_MCUS/TARGET_MIMXRT1050/TARGET_EVK/PeripheralPins.c

@@ -39,12 +39,12 @@ const PinMap PinMap_DAC[] = {
 
 /************I2C***************/
 const PinMap PinMap_I2C_SDA[] = {
-    {GPIO_AD_B1_01, I2C_1, ((1U << DAISY_REG_VALUE_SHIFT) | (0x4D0 << DAISY_REG_SHIFT) | 3)},
+    {GPIO_AD_B1_01, I2C_1, ((1U << DAISY_REG_VALUE_SHIFT) | (0x4D0 << DAISY_REG_SHIFT) | (1U << SION_BIT_SHIFT) | 3)},
     {NC   , NC   , 0}
 };
 
 const PinMap PinMap_I2C_SCL[] = {
-    {GPIO_AD_B1_00, I2C_1, ((1U << DAISY_REG_VALUE_SHIFT) | (0x4CC << DAISY_REG_SHIFT) | 3)},
+    {GPIO_AD_B1_00, I2C_1, ((1U << DAISY_REG_VALUE_SHIFT) | (0x4CC << DAISY_REG_SHIFT) | (1U << SION_BIT_SHIFT) | 3)},
     {NC   , NC   , 0}
 };