Add word register read/write commands to I2C driver

kestrel/src/opencores_i2c.c

-// © 2020 - 2022 Raptor Engineering, LLC
+// © 2020 - 2023 Raptor Engineering, LLC
 //
 // Released under the terms of the LGPL v3+
 // See the LICENSE file for full details
@@ -257,6 +257,32 @@ uint8_t i2c_read_register_byte(uint8_t *base_address, uint8_t slave_address, uin
     return retval;
 }
 
+uint16_t i2c_read_register_word(uint8_t *base_address, uint8_t slave_address, uint8_t slave_register, int *error)
+{
+    uint16_t retval = 0xffff;
+    uint8_t byte[2];
+
+    if (error)
+    {
+        *error = -1;
+    }
+
+    if (!write_i2c_data(base_address, slave_address, &slave_register, 1, 0))
+    {
+        if (!read_i2c_data(base_address, slave_address, &byte, NULL, 2, 1))
+        {
+            retval = byte[0] << 8;
+            retval |= byte[1];
+            if (error)
+            {
+                *error = 0;
+            }
+        }
+    }
+
+    return retval;
+}
+
 int i2c_write_register_byte(uint8_t *base_address, uint8_t slave_address, uint8_t slave_register, uint8_t data)
 {
     uint8_t tx_data[2];
@@ -271,4 +297,21 @@ int i2c_write_register_byte(uint8_t *base_address, uint8_t slave_address, uint8_
     }
 
     return 1;
-}
\ No newline at end of file
+}
+
+int i2c_write_register_word(uint8_t *base_address, uint8_t slave_address, uint8_t slave_register, uint16_t data)
+{
+    uint8_t tx_data[3];
+
+    // Assemble TX data structure
+    tx_data[0] = slave_register;
+    tx_data[1] = (data >> 16) & 0xff;
+    tx_data[2] = data & 0xff;
+
+    if (!write_i2c_data(base_address, slave_address, tx_data, 3, 1))
+    {
+        return 0;
+    }
+
+    return 1;
+}

kestrel/src/opencores_i2c.h

-// © 2020 - 2022 Raptor Engineering, LLC
+// © 2020 - 2023 Raptor Engineering, LLC
 //
 // Released under the terms of the LGPL v3+
 // See the LICENSE file for full details
@@ -70,6 +70,8 @@ int initialize_i2c_master(uint8_t *base_address, int i2c_bus_frequency);
 int write_i2c_data(uint8_t *base_address, uint8_t slave_address, uint8_t *data, int data_length, uint8_t send_stop_signal);
 int read_i2c_data(uint8_t *base_address, uint8_t slave_address, uint8_t *data, int *data_length, int max_data_length, uint8_t send_stop_signal);
 uint8_t i2c_read_register_byte(uint8_t *base_address, uint8_t slave_address, uint8_t slave_register, int *error);
+uint16_t i2c_read_register_word(uint8_t *base_address, uint8_t slave_address, uint8_t slave_register, int *error);
 int i2c_write_register_byte(uint8_t *base_address, uint8_t slave_address, uint8_t slave_register, uint8_t data);
+int i2c_write_register_word(uint8_t *base_address, uint8_t slave_address, uint8_t slave_register, uint16_t data);
 
 #endif // _OPENCORES_I2C_H