diff options
Diffstat (limited to 'libmaple/i2c.c')
| -rw-r--r-- | libmaple/i2c.c | 96 |
1 files changed, 52 insertions, 44 deletions
diff --git a/libmaple/i2c.c b/libmaple/i2c.c index 0ef8e70..8f6967b 100644 --- a/libmaple/i2c.c +++ b/libmaple/i2c.c @@ -26,8 +26,9 @@ /** * @file i2c.c - * @brief Inter-Integrated Circuit (I2C) support. Currently supports only master - * mode. + * @brief Inter-Integrated Circuit (I2C) support. + * + * Currently, only master mode is supported. */ #include "libmaple.h" @@ -43,11 +44,12 @@ static i2c_dev i2c_dev1 = { .gpio_port = &gpiob, .sda_pin = 7, .scl_pin = 6, - .clk_line = RCC_I2C1, + .clk_id = RCC_I2C1, .ev_nvic_line = NVIC_I2C1_EV, .er_nvic_line = NVIC_I2C1_ER, .state = I2C_STATE_DISABLED }; +/** I2C1 device */ i2c_dev* const I2C1 = &i2c_dev1; static i2c_dev i2c_dev2 = { @@ -55,11 +57,12 @@ static i2c_dev i2c_dev2 = { .gpio_port = &gpiob, .sda_pin = 11, .scl_pin = 10, - .clk_line = RCC_I2C2, + .clk_id = RCC_I2C2, .ev_nvic_line = NVIC_I2C2_EV, .er_nvic_line = NVIC_I2C2_ER, .state = I2C_STATE_DISABLED }; +/** I2C2 device */ i2c_dev* const I2C2 = &i2c_dev2; static inline int32 wait_for_state_change(i2c_dev *dev, @@ -68,9 +71,9 @@ static inline int32 wait_for_state_change(i2c_dev *dev, /** * @brief Fill data register with slave address - * @param dev i2c device - * @param addr slave address - * @param rw read/write bit + * @param dev I2C device + * @param addr Slave address + * @param rw Read/write bit */ static inline void i2c_send_slave_addr(i2c_dev *dev, uint32 addr, uint32 rw) { dev->regs->DR = (addr << 1) | rw; @@ -121,10 +124,9 @@ enum { ERROR_ENTRY = 13, }; - /** - * @brief IRQ handler for i2c master. Handles transmission/reception. - * @param dev i2c device + * @brief IRQ handler for I2C master. Handles transmission/reception. + * @param dev I2C device */ static void i2c_irq_handler(i2c_dev *dev) { i2c_msg *msg = dev->msg; @@ -294,11 +296,10 @@ void __irq_i2c2_ev(void) { i2c_irq_handler(&i2c_dev2); } - /** - * @brief Interrupt handler for i2c error conditions - * @param dev i2c device - * @sideeffect Aborts any pending i2c transactions + * @brief Interrupt handler for I2C error conditions + * @param dev I2C device + * @sideeffect Aborts any pending I2C transactions */ static void i2c_irq_error_handler(i2c_dev *dev) { I2C_CRUMB(ERROR_ENTRY, dev->regs->SR1, dev->regs->SR2); @@ -324,12 +325,14 @@ void __irq_i2c2_er(void) { i2c_irq_error_handler(&i2c_dev2); } - /** - * @brief Reset an i2c bus by clocking out pulses until any hung - * slaves release SDA and SCL, then generate a START condition, then - * a STOP condition. - * @param dev i2c device + * @brief Reset an I2C bus. + * + * Reset is accomplished by clocking out pulses until any hung slaves + * release SDA and SCL, then generating a START condition, then a STOP + * condition. + * + * @param dev I2C device */ void i2c_bus_reset(const i2c_dev *dev) { /* Release both lines */ @@ -370,22 +373,24 @@ void i2c_bus_reset(const i2c_dev *dev) { /** * @brief Initialize an I2C device and reset its registers to their * default values. - * @param dev Device to enable. + * @param dev Device to initialize. */ void i2c_init(i2c_dev *dev) { - rcc_reset_dev(dev->clk_line); - rcc_clk_enable(dev->clk_line); + rcc_reset_dev(dev->clk_id); + rcc_clk_enable(dev->clk_id); } /** - * @brief Initialize an i2c device as bus master + * @brief Initialize an I2C device as bus 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: Remap I2C1 to SCL/PB8 SDA/PB9 + * 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: Remap I2C1 to SCL/PB8 SDA/PB9. */ void i2c_master_enable(i2c_dev *dev, uint32 flags) { #define I2C_CLK (PCLK1/1000000) @@ -484,17 +489,20 @@ void i2c_master_enable(i2c_dev *dev, uint32 flags) { /** - * @brief Process an i2c transaction. Transactions are composed of - * one or more i2c_msg's and may be read or write tranfers. Multiple i2c_msg's - * will generate a repeated start inbetween messages. - * @param dev i2c device - * @param msgs messages to send/receive - * @param num number of messages to send/receive - * @param timeout bus idle timeout in milliseconds before aborting the - * transfer. 0 denotes no timeout. - * @return 0 on success - * I2C_ERROR_PROTOCOL if there was a protocol error. - * I2C_ERROR_TIMEOUT if the transfer timed out. + * @brief Process an i2c transaction. + * + * Transactions are composed of one or more i2c_msg's, and may be read + * or write tranfers. Multiple i2c_msg's will generate a repeated + * start in between messages. + * + * @param dev I2C device + * @param msgs Messages to send/receive + * @param num Number of messages to send/receive + * @param timeout Bus idle timeout in milliseconds before aborting the + * transfer. 0 denotes no timeout. + * @return 0 on success, + * I2C_ERROR_PROTOCOL if there was a protocol error, + * I2C_ERROR_TIMEOUT if the transfer timed out. */ int32 i2c_master_xfer(i2c_dev *dev, i2c_msg *msgs, @@ -524,11 +532,11 @@ out: /** - * @brief Wait for an i2c event, or timeout in case of error - * @param dev i2c device - * @param state i2c_state state to wait for - * @param timeout timeout in milliseconds - * @return 0 if target state is reached, <0 on error + * @brief Wait for an I2C event, or time out in case of error. + * @param dev I2C device + * @param state I2C_state state to wait for + * @param timeout Timeout, in milliseconds + * @return 0 if target state is reached, a negative value on error. */ static inline int32 wait_for_state_change(i2c_dev *dev, i2c_state state, |