Diff: source/family/arm/musca_b/i2c_gpio.c

Revision:

0:01f31e923fe2

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/source/family/arm/musca_b/i2c_gpio.c	Tue Apr 07 12:55:42 2020 +0200
@@ -0,0 +1,262 @@
+/**
+ * @file    i2c_gpio.c
+ * @brief   I2C GPIO control for musca PCA9537
+ *
+ * DAPLink Interface Firmware
+ * Copyright (c) 2009-2016, ARM Limited, All Rights Reserved
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "string.h"
+#include "stdio.h"
+#include "stdint.h"
+
+#include "gpio.h"
+#include "utils.h"
+#include "i2c_gpio.h"
+
+// Clock registers
+#define I2CGPIO_FREQ    6            // Sets OSC Clock SCL frequency
+#define I2CGPIO_WR      0            // Write command
+#define I2CGPIO_RD      1            // Read command
+#define I2CGPIO_ADDR    0x49         // Default slave address for PCA9537
+
+/*----------------------------------------------------------------------------
+  I2C Address + Wr + A
+ *----------------------------------------------------------------------------*/
+void i2c_gpio_addr(unsigned int addr, unsigned int read)
+{
+    unsigned int loop, data;
+    
+    // Repeated Start condition (if required after Command)
+    LPC_GPIO->DIR[PIN_I2C_SCL_PORT] &= ~PIN_I2C_SCL;
+    delay_us(I2CGPIO_FREQ);
+    LPC_GPIO->DIR[PIN_I2C_SDA_PORT] &= ~PIN_I2C_SDA;
+    delay_us(I2CGPIO_FREQ);
+    
+    // Start condition 'S' (DATA > CLK)
+    LPC_GPIO->DIR[PIN_I2C_SDA_PORT] |= PIN_I2C_SDA;
+    delay_us(I2CGPIO_FREQ);
+    LPC_GPIO->DIR[PIN_I2C_SCL_PORT] |= PIN_I2C_SCL;
+    delay_us(I2CGPIO_FREQ);
+    
+    // Addr is 7 bits so add Read
+    data = (addr << 1) & 0xFE;
+    if (read)
+        data |= 0x01;
+    
+    // Clock out the 8 bits
+    for (loop = 0; loop < 8; loop++)
+    {
+        if (data & (0x80 >> loop))
+        {
+            LPC_GPIO->DIR[PIN_I2C_SDA_PORT] &= ~PIN_I2C_SDA;
+            delay_us(I2CGPIO_FREQ);
+            LPC_GPIO->DIR[PIN_I2C_SCL_PORT] &= ~PIN_I2C_SCL;
+            delay_us(I2CGPIO_FREQ);
+            LPC_GPIO->DIR[PIN_I2C_SCL_PORT] |= PIN_I2C_SCL;
+            delay_us(I2CGPIO_FREQ);
+        }
+        else
+        {
+            LPC_GPIO->DIR[PIN_I2C_SDA_PORT] |= PIN_I2C_SDA;
+            delay_us(I2CGPIO_FREQ);
+            LPC_GPIO->DIR[PIN_I2C_SCL_PORT] &= ~PIN_I2C_SCL;
+            delay_us(I2CGPIO_FREQ);
+            LPC_GPIO->DIR[PIN_I2C_SCL_PORT] |= PIN_I2C_SCL;
+            delay_us(I2CGPIO_FREQ);
+        }
+    }
+
+    // Set data low
+    delay_us(I2CGPIO_FREQ);
+    LPC_GPIO->DIR[PIN_I2C_SDA_PORT] |= PIN_I2C_SDA;
+    delay_us(I2CGPIO_FREQ);
+    
+    // Transmission clock 'A'
+    LPC_GPIO->DIR[PIN_I2C_SCL_PORT] &= ~PIN_I2C_SCL;
+    delay_us(I2CGPIO_FREQ);
+    LPC_GPIO->DIR[PIN_I2C_SCL_PORT] |= PIN_I2C_SCL;
+    delay_us(I2CGPIO_FREQ);
+}
+
+/*----------------------------------------------------------------------------
+  I2C Command + A
+ *----------------------------------------------------------------------------*/
+void i2c_gpio_cmd(unsigned int cmd)
+{
+    unsigned int loop;
+    
+    // Clock out the 8 bits
+    for (loop = 0; loop < 8; loop++)
+    {
+        if (cmd & (0x80 >> loop))
+        {
+            LPC_GPIO->DIR[PIN_I2C_SDA_PORT] &= ~PIN_I2C_SDA;
+            delay_us(I2CGPIO_FREQ);
+            LPC_GPIO->DIR[PIN_I2C_SCL_PORT] &= ~PIN_I2C_SCL;
+            delay_us(I2CGPIO_FREQ);
+            LPC_GPIO->DIR[PIN_I2C_SCL_PORT] |= PIN_I2C_SCL;
+            delay_us(I2CGPIO_FREQ);
+        }
+        else
+        {
+            LPC_GPIO->DIR[PIN_I2C_SDA_PORT] |= PIN_I2C_SDA;
+            delay_us(I2CGPIO_FREQ);
+            LPC_GPIO->DIR[PIN_I2C_SCL_PORT] &= ~PIN_I2C_SCL;
+            delay_us(I2CGPIO_FREQ);
+            LPC_GPIO->DIR[PIN_I2C_SCL_PORT] |= PIN_I2C_SCL;
+            delay_us(I2CGPIO_FREQ);
+        }
+    }
+
+    // Set data low
+    delay_us(I2CGPIO_FREQ);
+    LPC_GPIO->DIR[PIN_I2C_SDA_PORT] |= PIN_I2C_SDA;
+    delay_us(I2CGPIO_FREQ);
+    
+    // Transmission clock 'A'
+    LPC_GPIO->DIR[PIN_I2C_SCL_PORT] &= ~PIN_I2C_SCL;
+    delay_us(I2CGPIO_FREQ);
+    LPC_GPIO->DIR[PIN_I2C_SCL_PORT] |= PIN_I2C_SCL;
+    delay_us(I2CGPIO_FREQ);
+}
+
+/*----------------------------------------------------------------------------
+  I2C Write Data + A + P
+ *----------------------------------------------------------------------------*/
+void i2c_gpio_write(unsigned int data)
+{
+    unsigned int loop;
+    
+    // Clock out the 8 bits
+    for (loop = 0; loop < 8; loop++)
+    {
+        if (data & (0x80 >> loop))
+        {
+            LPC_GPIO->DIR[PIN_I2C_SDA_PORT] &= ~PIN_I2C_SDA;
+            delay_us(I2CGPIO_FREQ);
+            LPC_GPIO->DIR[PIN_I2C_SCL_PORT] &= ~PIN_I2C_SCL;
+            delay_us(I2CGPIO_FREQ);
+            LPC_GPIO->DIR[PIN_I2C_SCL_PORT] |= PIN_I2C_SCL;
+            delay_us(I2CGPIO_FREQ);
+        }
+        else
+        {
+            LPC_GPIO->DIR[PIN_I2C_SDA_PORT] |= PIN_I2C_SDA;
+            delay_us(I2CGPIO_FREQ);
+            LPC_GPIO->DIR[PIN_I2C_SCL_PORT] &= ~PIN_I2C_SCL;
+            delay_us(I2CGPIO_FREQ);
+            LPC_GPIO->DIR[PIN_I2C_SCL_PORT] |= PIN_I2C_SCL;
+            delay_us(I2CGPIO_FREQ);
+        }
+    }
+
+    // Set data low
+    delay_us(I2CGPIO_FREQ);
+    LPC_GPIO->DIR[PIN_I2C_SDA_PORT] |= PIN_I2C_SDA;
+    delay_us(I2CGPIO_FREQ);
+    
+    // Transmission clock 'A'
+    LPC_GPIO->DIR[PIN_I2C_SCL_PORT] &= ~PIN_I2C_SCL;
+    delay_us(I2CGPIO_FREQ);
+    LPC_GPIO->DIR[PIN_I2C_SCL_PORT] |= PIN_I2C_SCL;
+    delay_us(I2CGPIO_FREQ);
+    
+    // Stop condition 'P'
+    LPC_GPIO->DIR[PIN_I2C_SCL_PORT] &= ~PIN_I2C_SCL;
+    delay_us(I2CGPIO_FREQ);
+    LPC_GPIO->DIR[PIN_I2C_SDA_PORT] &= ~PIN_I2C_SDA;
+    delay_us(I2CGPIO_FREQ);
+}
+
+/*----------------------------------------------------------------------------
+  I2C Read Data + A + P
+ *----------------------------------------------------------------------------*/
+void i2c_gpio_read(unsigned int *data, unsigned int ack)
+{
+    unsigned int loop;
+    
+    // Set SDA high (O/D) and allow PCA9537 to drive SDA
+    LPC_GPIO->DIR[PIN_I2C_SDA_PORT] &= ~PIN_I2C_SDA;
+    delay_us(I2CGPIO_FREQ);
+    
+    // Clock in the 8 bits
+    *data = 0;
+    for (loop = 0; loop < 8; loop++)
+    {
+        LPC_GPIO->DIR[PIN_I2C_SCL_PORT] &= ~PIN_I2C_SCL;
+        delay_us(I2CGPIO_FREQ);
+        if (LPC_GPIO->DIR[PIN_I2C_SDA_PORT] & PIN_I2C_SDA)
+            *data &= ~(0x80 >> loop);
+        LPC_GPIO->DIR[PIN_I2C_SCL_PORT] |= PIN_I2C_SCL;
+        delay_us(I2CGPIO_FREQ);
+    }
+
+    // Set data for acknowledge
+    delay_us(I2CGPIO_FREQ);
+    if (ack)
+        LPC_GPIO->DIR[PIN_I2C_SDA_PORT] |= PIN_I2C_SDA;
+    else
+        LPC_GPIO->DIR[PIN_I2C_SDA_PORT] &= ~PIN_I2C_SDA;
+    delay_us(I2CGPIO_FREQ);
+        
+    // Transmission clock 'A'
+    LPC_GPIO->DIR[PIN_I2C_SCL_PORT] &= ~PIN_I2C_SCL;
+    delay_us(I2CGPIO_FREQ);
+    LPC_GPIO->DIR[PIN_I2C_SCL_PORT] |= PIN_I2C_SCL;
+    delay_us(I2CGPIO_FREQ);
+
+    // End of acknowledge
+    LPC_GPIO->DIR[PIN_I2C_SDA_PORT] |= PIN_I2C_SDA;
+    delay_us(I2CGPIO_FREQ);
+    
+    // Stop condition 'P'
+    LPC_GPIO->DIR[PIN_I2C_SCL_PORT] &= ~PIN_I2C_SCL;
+    delay_us(I2CGPIO_FREQ);
+    LPC_GPIO->DIR[PIN_I2C_SDA_PORT] &= ~PIN_I2C_SDA;
+    delay_us(I2CGPIO_FREQ);
+}
+
+/*----------------------------------------------------------------------------
+  I2C Write byte
+ *----------------------------------------------------------------------------*/
+void i2c_gpio_wbyte(unsigned int cmd, unsigned int data)
+{
+    // Set slave address write
+    i2c_gpio_addr(I2CGPIO_ADDR, I2CGPIO_WR);
+    // Set command
+    i2c_gpio_cmd(cmd);
+    // Write the data
+    i2c_gpio_write(data);
+}
+
+/*----------------------------------------------------------------------------
+  I2C Read byte
+ *----------------------------------------------------------------------------*/
+void i2c_gpio_rbyte(unsigned int cmd, unsigned int *data)
+{
+    // Set slave address write
+    i2c_gpio_addr(I2CGPIO_ADDR, I2CGPIO_WR);
+    // Set command
+    i2c_gpio_cmd(cmd);
+    
+    // Set slave address write
+    i2c_gpio_addr(I2CGPIO_ADDR, I2CGPIO_RD);
+    // Read the data
+    i2c_gpio_read(data, 0);
+}
+
+// end of i2c_gpio.c