From ef5c4b9f30da2f4b9a0edd4231e95b3ef8a88d43 Mon Sep 17 00:00:00 2001
From: Barry Carter <barry.carter@robotfuzz.com>
Date: Mon, 3 Sep 2012 17:45:58 +0100
Subject: - tx and rx callbacks for each module  - Callbacks can be called
 after each read/write cycle or per byte  - Each I2C module can have different
 callbacks  - General call support also working  - Supports master and slave
 at same time. Also works with multimaster

Usage:

i2c_msg msg;
char buffer[255];

main()
{
    i2c_slave_enable(I2C1, I2C_FAST_MODE | I2C_SLAVE_DUAL_ADDRESS | I2C_SLAVE_GENERAL_CALL | I2C_SLAVE_USE_RX_BUFFER); // init slave mode. Enables master too
    i2c_slave_attach_recv_handler(I2C1, pmsg, funcrx); // attach  receive handler
    i2c_slave_attach_transmit_handler(I2C1, pmsg, functx);   // attach transmit handler
    i2c_slave_set_own_address(I2C1, 0x10);    // set addresss 1
    i2c_slave_set_own_address2(I2C1, 0x20);   // set addresss 2
}

void funcrx(i2c_msg *msg)
{
    printf("length is %d.\n", msg->length);
    char return_data = msg0>data[0];
}

void functx(i2c_msg *dev)
{
    msg->data[0] = 0x01;
    msg->data[1] = 0x02;
    msg->data[2] = 0x03;
    msg->data[3] = 0x04;
    msg->data[4] = 0x05;
    msg->length = 5;
}

All code derived from datasheets and libmaple.
Signed-off-by:- Barry Carter <barry.carter@gmail.com>
---
 libmaple/include/libmaple/i2c.h | 52 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

(limited to 'libmaple/include/libmaple/i2c.h')

diff --git a/libmaple/include/libmaple/i2c.h b/libmaple/include/libmaple/i2c.h
index ff1c313..d4eac61 100644
--- a/libmaple/include/libmaple/i2c.h
+++ b/libmaple/include/libmaple/i2c.h
@@ -93,6 +93,7 @@ typedef struct i2c_msg {
 
 #define I2C_MSG_READ            0x1
 #define I2C_MSG_10BIT_ADDR      0x2
+
     /**
      * Bitwise OR of:
      * - I2C_MSG_READ (write is default)
@@ -197,6 +198,10 @@ typedef struct i2c_msg {
 #define I2C_DUTY_16_9           0x2           // 16/9 duty ratio
 /* Flag 0x4 is reserved; DO NOT USE. */
 #define I2C_BUS_RESET           0x8           // Perform a bus reset
+#define I2C_SLAVE_USE_RX_BUFFER 0x10          // Use a buffered message when doing a slave recv
+#define I2C_SLAVE_USE_TX_BUFFER 0x20          // Use a buffered message when doing a slave transmit
+#define I2C_SLAVE_DUAL_ADDRESS  0x40          // Enable the dual slave address scheme
+#define I2C_SLAVE_GENERAL_CALL  0x80          // Enable the dual slave address scheme
 void i2c_master_enable(i2c_dev *dev, uint32 flags);
 
 #define I2C_ERROR_PROTOCOL      (-1)
@@ -406,6 +411,53 @@ static inline void i2c_set_trise(i2c_dev *dev, uint32 trise) {
     dev->regs->TRISE = trise;
 }
 
+/* Barry Carter
+ * Slave support
+ */
+
+/**
+ * @brief Enable Dual addressing mode to allow peripheral to have 2 addresses
+ * @param dev I2C device
+  */
+static inline void i2c_slave_dual_address_enable(i2c_dev *dev) {
+    dev->regs->OAR2 |= I2C_OAR2_ENDUAL;
+}
+
+/**
+ * @brief Enable General Call to allow the  unit to respond on addr 0x00
+ * @param dev I2C device
+  */
+static inline void i2c_slave_general_call_enable(i2c_dev *dev) {
+    dev->regs->CR1 |= I2C_CR1_ENGC;
+}
+
+/* callback functions */
+/* Callback handler for data received over the bus */
+void i2c_slave_attach_recv_handler(i2c_dev *dev, i2c_msg *msg, i2c_slave_recv_callback_func func);
+
+/* Callback handler for data being requested over the bus
+ * The callback function must call i2c_write to get the data over the bus
+ */
+void i2c_slave_attach_transmit_handler(i2c_dev *dev, i2c_msg *msg, i2c_slave_transmit_callback_func func);
+
+/**
+ * @brief Set the primary I2c slave address
+ * @param dev I2C device
+ * @param address the 8 or 10 bit i2c address
+  */
+static inline void i2c_slave_set_own_address(i2c_dev *dev, uint16 address) {
+    dev->regs->OAR1 = address <<1;
+}
+
+/**
+ * @brief Set the secondary I2c slave address
+ * @param dev I2C device
+ * @param address the 8 or 10 bit i2c address
+  */
+static inline void i2c_slave_set_own_address2(i2c_dev *dev, uint16 address) {
+dev->regs->OAR2 = (address <<1 ) | I2C_OAR2_ENDUAL;
+}
+
 #ifdef __cplusplus
 }
 #endif
-- 
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