diff options
Diffstat (limited to 'libmaple/i2c.c')
| -rw-r--r-- | libmaple/i2c.c | 271 |
1 files changed, 2 insertions, 269 deletions
diff --git a/libmaple/i2c.c b/libmaple/i2c.c index bbbf123..9c93d3f 100644 --- a/libmaple/i2c.c +++ b/libmaple/i2c.c @@ -28,11 +28,9 @@ /** * @file libmaple/i2c.c * @author Perry Hung <perry@leaflabs.com> - * @author Barry Carter <barry.carter@gmail.com> * @brief Inter-Integrated Circuit (I2C) support. * - * Master and Slave supported - * Slave code added Barry Carter 2012 + * Currently, only master mode is supported. */ #include "i2c_private.h" @@ -156,7 +154,6 @@ void i2c_bus_reset(const i2c_dev *dev) { void i2c_init(i2c_dev *dev) { rcc_reset_dev(dev->clk_id); rcc_clk_enable(dev->clk_id); - _i2c_irq_priority_fixup(dev); } /* Hack for deprecated bit of STM32F1 functionality */ @@ -201,51 +198,13 @@ void i2c_master_enable(i2c_dev *dev, uint32 flags) { nvic_irq_enable(dev->er_nvic_line); i2c_enable_irq(dev, I2C_IRQ_EVENT | I2C_IRQ_BUFFER | I2C_IRQ_ERROR); - /* Configure the slave unit */ - if (flags & I2C_SLAVE_DUAL_ADDRESS) { - i2c_slave_dual_address_enable(dev); - } - - if (flags & I2C_SLAVE_GENERAL_CALL) { - i2c_slave_general_call_enable(dev); - } - - /* store all of the flags */ - dev->config_flags = flags; - /* Make it go! */ i2c_peripheral_enable(dev); - i2c_enable_ack(dev); 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); -} - -/** * @brief Process an i2c transaction. * * Transactions are composed of one or more i2c_msg's, and may be read @@ -345,164 +304,6 @@ void _i2c_irq_handler(i2c_dev *dev) { dev->timestamp = systick_uptime(); /* - * 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 */ - - /* Check for address match */ - if (sr1 & I2C_SR1_ADDR) { - /* Find out which address was matched */ - /* Check the general call address first */ - if (sr2 & I2C_SR2_GENCALL) { - dev->i2c_slave_msg->addr = 0; - } - /* We matched the secondary address */ - else if (sr2 & I2C_SR2_DUALF) { - dev->i2c_slave_msg->addr = dev->regs->OAR2 & 0xFE; - } - /* We matched the primary address */ - else if ((sr2 & I2C_SR2_DUALF) != I2C_SR2_DUALF) { - dev->i2c_slave_msg->addr = dev->regs->OAR1 & 0xFE; - } - /* Shouldn't get here */ - else { - dev->i2c_slave_msg->addr = -1; /* uh oh */ - } - - /* if we have buffered io */ - if ((dev->config_flags & I2C_SLAVE_USE_RX_BUFFER) || - (dev->config_flags & I2C_SLAVE_USE_TX_BUFFER)) { - - /* if receiving then this would be a repeated start - * - *if we have some bytes already - */ - if ((dev->state == I2C_STATE_SL_RX) && - (dev->i2c_slave_msg->xferred > 0) && - (dev->config_flags & I2C_SLAVE_USE_RX_BUFFER)) { - /* Call the callback with the contents of the data */ - if (dev->i2c_slave_recv_callback != NULL) { - (*(dev->i2c_slave_recv_callback))(dev->i2c_slave_msg); - } - } - - /* Reset the message back to defaults. - * We are starting a new message - */ - dev->i2c_slave_msg->flags = 0; - dev->i2c_slave_msg->length = 0; - dev->i2c_slave_msg->xferred = 0; - dev->msgs_left = 0; - dev->timestamp = systick_uptime(); - - /* We have been addressed with SLA+R so - * the master wants us to transmit - */ - if ((sr1 & I2C_SR1_TXE) && - (dev->config_flags & I2C_SLAVE_USE_TX_BUFFER)) { - /* Call the transmit callback so it can populate the msg - * data with the bytes to go - */ - if (dev->i2c_slave_transmit_callback != NULL) { - (*(dev->i2c_slave_transmit_callback))(dev->i2c_slave_msg); - } - } - dev->state = I2C_STATE_BUSY; - } - - sr1 = sr2 = 0; - } - - /* EV3: Master requesting data from slave. Transmit a byte*/ - if (sr1 & I2C_SR1_TXE) { - if (dev->config_flags & I2C_SLAVE_USE_TX_BUFFER) { - if (dev->i2c_slave_msg->xferred >= dev->i2c_slave_msg->length) { - /* End of the transmit buffer? If so we NACK */ - i2c_disable_ack(dev); - /* We have to either issue a STOP or write something here. - * STOP here seems to screw up some masters, - * For now padding with 0 - */ - i2c_write(dev, 0); - /*i2c_stop_condition(dev); // This is causing bus lockups way more than it should !? Seems some I2C master devices freak out here*/ - } - else - { - /* NACk the last byte */ - if (dev->i2c_slave_msg->xferred == dev->i2c_slave_msg->length-1) { - i2c_disable_ack(dev); - } - else { - i2c_enable_ack(dev); - } - i2c_write(dev, dev->i2c_slave_msg->data[dev->i2c_slave_msg->xferred++]); - } - } - else - { - /* Call the callback to get the data we need. - * The callback is expected to write using i2c_write(...) - * If the slave is going to terminate the transfer, this function should - * also do a NACK on the last byte! - */ - if (dev->i2c_slave_transmit_callback != NULL) (*(dev->i2c_slave_transmit_callback))(dev->i2c_slave_msg); - } - - dev->state = I2C_STATE_BUSY; - sr1 = sr2 = 0; - } - - /* EV2: Slave received data from a master. Get from DR */ - if (sr1 & I2C_SR1_RXNE) { - if (dev->config_flags & I2C_SLAVE_USE_RX_BUFFER) { - /* Fill the buffer with the contents of the data register */ - /* These is potential for buffer overflow here, so we should - * really store the size of the array. This is expensive in - * the ISR so left out for now. We must trust the implementor! - */ - dev->i2c_slave_msg->data[dev->i2c_slave_msg->xferred++] = dev->regs->DR; - dev->i2c_slave_msg->length++; - } - else { - /* Call the callback with the contents of the data */ - dev->i2c_slave_msg->data[0] = dev->regs->DR; - if (dev->i2c_slave_recv_callback != NULL) (*(dev->i2c_slave_recv_callback))(dev->i2c_slave_msg); - } - dev->state = I2C_STATE_SL_RX; - sr1 = sr2 = 0; - } - - /* EV4: Slave has detected a STOP condition on the bus */ - if (sr1 & I2C_SR1_STOPF) { - dev->regs->CR1 |= I2C_CR1_PE; - - if ((dev->config_flags & I2C_SLAVE_USE_RX_BUFFER) || - (dev->config_flags & I2C_SLAVE_USE_TX_BUFFER)) { - - /* 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; - dev->state = I2C_STATE_IDLE; - } - - return; - } - - /* * EV5: Start condition sent */ if (sr1 & I2C_SR1_SB) { @@ -646,7 +447,6 @@ void _i2c_irq_handler(i2c_dev *dev) { } } } - } /* @@ -656,49 +456,10 @@ void _i2c_irq_handler(i2c_dev *dev) { void _i2c_irq_error_handler(i2c_dev *dev) { I2C_CRUMB(ERROR_ENTRY, dev->regs->SR1, dev->regs->SR2); - dev->error_flags = dev->regs->SR1 & (I2C_SR1_BERR | + dev->error_flags = dev->regs->SR2 & (I2C_SR1_BERR | I2C_SR1_ARLO | I2C_SR1_AF | I2C_SR1_OVR); - - /* Are we in slave mode? */ - if ((dev->regs->SR2 & I2C_SR2_MSL) != I2C_SR2_MSL) { - /* Check to see if the master device did a NAK on the last bit - * This is perfectly valid for a master to do this on the bus. - * We ignore this. Any further error processing takes us into dead - * loop waiting for the stop condition that will never arrive - */ - if (dev->regs->SR1 & I2C_SR1_AF) { - /* Clear flags */ - dev->regs->SR1 = 0; - dev->regs->SR2 = 0; - /* We need to write something to CR1 to clear the flag. - * This isn't really mentioned but seems important */ - i2c_enable_ack(dev); - - if (dev->state == I2C_STATE_SL_RX && - dev->config_flags & I2C_SLAVE_USE_RX_BUFFER && - dev->i2c_slave_msg->xferred > 0) { - /* Call the callback with the contents of the data */ - if (dev->i2c_slave_recv_callback != NULL) (*(dev->i2c_slave_recv_callback))(dev->i2c_slave_msg); - } - - dev->state = I2C_STATE_IDLE; - return; - } - /* Catch any other strange errors while in slave mode. - * I have seen BERR caused by an over fast master device - * as well as several overflows and arbitration failures. - * We are going to reset SR flags and carry on at this point which - * is not the best thing to do, but stops the bus locking up completely - * If we carry on below and send the stop bit, the code spins forever */ - /* Clear flags */ - dev->regs->SR1 = 0; - dev->regs->SR2 = 0; - dev->state = I2C_STATE_IDLE; - return; - } - /* Clear flags */ dev->regs->SR1 = 0; dev->regs->SR2 = 0; @@ -746,31 +507,3 @@ static void set_ccr_trise(i2c_dev *dev, uint32 flags) { i2c_set_clk_control(dev, ccr); i2c_set_trise(dev, trise); } - - -/** - * @brief callback for when the device acts as a slave. If using an rx buffer, this is triggered - * after the last byte, otherwise it is called for every incoming packet. - * @param dev I2C device - * @param msg The dev_msg to pass to the slave init code - * @param func The function pointer to call - */ -void i2c_slave_attach_recv_handler(i2c_dev *dev, i2c_msg *msg, i2c_slave_recv_callback_func func) { - dev->i2c_slave_recv_callback = func; - dev->i2c_slave_msg = msg; - msg->xferred = 0; -} - - -/** - * @brief callback for when the device acts as a slave. If using a tx buffer, this is triggered - * after the device is successsfully addressed with SLA+R. - * @param dev I2C device - * @param msg The dev_msg to pass to the slave init code - * @param func The function pointer to call - */ -void i2c_slave_attach_transmit_handler(i2c_dev *dev, i2c_msg *msg, i2c_slave_transmit_callback_func func) { - dev->i2c_slave_transmit_callback = func; - dev->i2c_slave_msg = msg; - msg->xferred = 0; -} |