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-rw-r--r--libmaple/i2c.c40
-rw-r--r--libmaple/include/libmaple/i2c.h13
-rw-r--r--libmaple/include/libmaple/i2c_common.h2
3 files changed, 46 insertions, 9 deletions
diff --git a/libmaple/i2c.c b/libmaple/i2c.c
index b8e622d..6c609d9 100644
--- a/libmaple/i2c.c
+++ b/libmaple/i2c.c
@@ -28,9 +28,11 @@
/**
* @file libmaple/i2c.c
* @author Perry Hung <perry@leaflabs.com>
+ * @author Barry Carter <barry.carter@gmail.com>
* @brief Inter-Integrated Circuit (I2C) support.
*
- * Currently, only master mode is supported.
+ * Master and Slave supported
+ * Slave code added Barry Carter 2012
*/
#include "i2c_private.h"
@@ -218,6 +220,26 @@ void i2c_master_enable(i2c_dev *dev, uint32 flags) {
dev->state = I2C_STATE_IDLE;
}
+/**
+ * @brief Initialize an I2C device as slave (and master)
+ * @param dev Device to enable
+ * @param flags Bitwise or of the following I2C options:
+ * I2C_FAST_MODE: 400 khz operation,
+ * I2C_DUTY_16_9: 16/9 Tlow/Thigh duty cycle (only applicable for
+ * fast mode),
+ * I2C_BUS_RESET: Reset the bus and clock out any hung slaves on
+ * initialization,
+ * I2C_10BIT_ADDRESSING: Enable 10-bit addressing,
+ * I2C_REMAP: (deprecated, STM32F1 only) Remap I2C1 to SCL/PB8
+ * SDA/PB9.
+ * I2C_SLAVE_DUAL_ADDRESS: Slave can respond on 2 i2C addresses
+ * I2C_SLAVE_GENERAL_CALL: SLA+W broadcast to all general call
+ * listeners on bus. Addr 0x00
+ * I2C_SLAVE_USE_RX_BUFFER: Use a buffer to receive the incoming
+ * data. Callback at end of recv
+ * I2C_SLAVE_USE_TX_BUFFER: Use a buffer to transmit data.
+ * Callback will be called before tx
+ */
void i2c_slave_enable(i2c_dev *dev, uint32 flags) {
i2c_disable(dev);
i2c_master_enable(dev, dev->config_flags | flags);
@@ -322,11 +344,10 @@ void _i2c_irq_handler(i2c_dev *dev) {
*/
dev->timestamp = systick_uptime();
- /* Add Slave support
- * Barry Carter 2012
- * barry.carter@gmail.com
+ /*
+ * Add Slave support
*/
-
+
/* Check to see if MSL master slave bit is set */
if ((sr2 & I2C_SR2_MSL) != I2C_SR2_MSL) { /* 0 = slave mode 1 = master */
@@ -459,6 +480,15 @@ void _i2c_irq_handler(i2c_dev *dev) {
/* The callback with the data will happen on a NACK of the last data byte.
* This is handled in the error IRQ (AF bit)
*/
+ /* Handle the case where the master misbehaves by sending no NACK */
+ if (dev->state != I2C_STATE_IDLE) {
+ if (dev->state == I2C_STATE_SL_RX) {
+ if (dev->i2c_slave_recv_callback != NULL) (*(dev->i2c_slave_recv_callback))(dev->i2c_slave_msg);
+ }
+ else {
+ if (dev->i2c_slave_transmit_callback != NULL) (*(dev->i2c_slave_transmit_callback))(dev->i2c_slave_msg);
+ }
+ }
}
sr1 = sr2 = 0;
diff --git a/libmaple/include/libmaple/i2c.h b/libmaple/include/libmaple/i2c.h
index d4eac61..5a9da58 100644
--- a/libmaple/include/libmaple/i2c.h
+++ b/libmaple/include/libmaple/i2c.h
@@ -29,12 +29,19 @@
* @file libmaple/include/libmaple/i2c.h
* @brief Inter-Integrated Circuit (I2C) peripheral support
*
- * Currently master-only. Usage notes:
+ * Supports Master and Slave.
+ * Master Usage notes:
*
* - Enable an I2C device with i2c_master_enable().
* - Initialize an array of struct i2c_msg to suit the bus
* transactions (reads/writes) you wish to perform.
* - Call i2c_master_xfer() to do the work.
+ *
+ * Slave Usage notes:
+ * - Enable I2C slave by calling i2c_slave_enable().
+ * Check flags for usage. Enabling master also enabled slave.
+ * - initialise the i2c_msg struct and the data buffer
+ * - initialise the callback functions
*/
#ifndef _LIBMAPLE_I2C_H_
@@ -201,7 +208,7 @@ typedef struct i2c_msg {
#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
+#define I2C_SLAVE_GENERAL_CALL 0x80 // Enable the general call on address 0x00
void i2c_master_enable(i2c_dev *dev, uint32 flags);
#define I2C_ERROR_PROTOCOL (-1)
@@ -411,7 +418,7 @@ static inline void i2c_set_trise(i2c_dev *dev, uint32 trise) {
dev->regs->TRISE = trise;
}
-/* Barry Carter
+/*
* Slave support
*/
diff --git a/libmaple/include/libmaple/i2c_common.h b/libmaple/include/libmaple/i2c_common.h
index 5debcb8..93e17e2 100644
--- a/libmaple/include/libmaple/i2c_common.h
+++ b/libmaple/include/libmaple/i2c_common.h
@@ -93,7 +93,7 @@ typedef struct i2c_dev {
volatile i2c_state state; /**< Device state */
uint32 config_flags; /**< Configuration flags */
- /* Barry Carter
+ /*
* Slave implementation. Callback functions in this struct allow
* for a separate callback function for each I2C unit available onboard
*/