diff options
| -rw-r--r-- | libmaple/i2c.c | 40 | ||||
| -rw-r--r-- | libmaple/include/libmaple/i2c.h | 13 | ||||
| -rw-r--r-- | libmaple/include/libmaple/i2c_common.h | 2 |
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 */ |