diff options
Diffstat (limited to 'libopencm3/lib/stm32/f3/i2c.c')
| -rw-r--r-- | libopencm3/lib/stm32/f3/i2c.c | 486 |
1 files changed, 486 insertions, 0 deletions
diff --git a/libopencm3/lib/stm32/f3/i2c.c b/libopencm3/lib/stm32/f3/i2c.c new file mode 100644 index 0000000..b5d39cf --- /dev/null +++ b/libopencm3/lib/stm32/f3/i2c.c @@ -0,0 +1,486 @@ +/** @defgroup i2c_file I2C + * + * @ingroup STM32F3xx + * + * @brief <b>libopencm3 STM32F3xx I2C</b> + * + * @version 1.0.0 + * + * @date 15 October 2012 + * + * LGPL License Terms @ref lgpl_license + */ + +/* + * This file is part of the libopencm3 project. + * + * This library is free software: you can redistribute it and/or modify + * it under the terms of the GNU Lesser General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public License + * along with this library. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <libopencm3/stm32/i2c.h> +#include <libopencm3/stm32/rcc.h> + +/**@{*/ + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Reset. + * + * The I2C peripheral and all its associated configuration registers are placed + * in the reset condition. The reset is effected via the RCC peripheral reset + * system. + * + * @param[in] i2c Unsigned int32. I2C peripheral identifier @ref i2c_reg_base. + */ + +void i2c_reset(uint32_t i2c) +{ + switch (i2c) { + case I2C1: + rcc_peripheral_reset(&RCC_APB1RSTR, RCC_APB1RSTR_I2C1RST); + rcc_peripheral_clear_reset(&RCC_APB1RSTR, RCC_APB1RSTR_I2C1RST); + break; + case I2C2: + rcc_peripheral_reset(&RCC_APB1RSTR, RCC_APB1RSTR_I2C2RST); + rcc_peripheral_clear_reset(&RCC_APB1RSTR, RCC_APB1RSTR_I2C2RST); + break; + } +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Peripheral Enable. + * + * @param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. + */ + +void i2c_peripheral_enable(uint32_t i2c) +{ + I2C_CR1(i2c) |= I2C_CR1_PE; +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Peripheral Disable. + * + * This must not be reset while in Master mode until a communication has + * finished. In Slave mode, the peripheral is disabled only after communication + * has ended. + * + * @param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. + */ + +void i2c_peripheral_disable(uint32_t i2c) +{ + I2C_CR1(i2c) &= ~I2C_CR1_PE; +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Send Start Condition. + * + * If in Master mode this will cause a restart condition to occur at the end of + * the current transmission. If in Slave mode, this will initiate a start + * condition when the current bus activity is completed. + * + * @param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. + */ + +void i2c_send_start(uint32_t i2c) +{ + I2C_CR2(i2c) |= I2C_CR2_START; +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Send Stop Condition. + * + * After the current byte transfer this will initiate a stop condition if in + * Master mode, or simply release the bus if in Slave mode. + * + * @param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. + */ + +void i2c_send_stop(uint32_t i2c) +{ + I2C_CR2(i2c) |= I2C_CR2_STOP; +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Clear Stop Flag. + * + * Clear the "Send Stop" flag in the I2C config register + * + * @param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. + */ +void i2c_clear_stop(uint32_t i2c) +{ + I2C_ICR(i2c) |= I2C_ICR_STOPCF; +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Set the 7 bit Slave Address for the Peripheral. + * + * This sets an address for Slave mode operation, in 7 bit form. + * + * @param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. + * @param[in] slave Unsigned int8. Slave address 0...127. + */ + +void i2c_set_own_7bit_slave_address(uint32_t i2c, uint8_t slave) +{ + I2C_OAR1(i2c) = (uint16_t)(slave << 1); + I2C_OAR1(i2c) &= ~I2C_OAR1_OA1MODE; + I2C_OAR1(i2c) |= (1 << 14); /* Datasheet: always keep 1 by software. */ +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Set the 10 bit Slave Address for the Peripheral. + * + * This sets an address for Slave mode operation, in 10 bit form. + * + * @todo add "I2C_OAR1(i2c) |= (1 << 14);" as above + * + * @param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. + * @param[in] slave Unsigned int16. Slave address 0...1023. + */ + +void i2c_set_own_10bit_slave_address(uint32_t i2c, uint16_t slave) +{ + I2C_OAR1(i2c) = (uint16_t)(I2C_OAR1_OA1MODE | slave); +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Send Data. + * + * @param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. + * @param[in] data Unsigned int8. Byte to send. + */ + +void i2c_send_data(uint32_t i2c, uint8_t data) +{ + I2C_TXDR(i2c) = data; +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Get Data. + * + * @param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. + */ +uint8_t i2c_get_data(uint32_t i2c) +{ + return I2C_RXDR(i2c) & 0xff; +} + +void i2c_enable_analog_filter(uint32_t i2c) +{ + I2C_CR1(i2c) &= ~I2C_CR1_ANFOFF; +} + +void i2c_disable_analog_filter(uint32_t i2c) +{ + I2C_CR1(i2c) |= I2C_CR1_ANFOFF; +} + +void i2c_set_digital_filter(uint32_t i2c, uint8_t dnf_setting) +{ + I2C_CR1(i2c) = (I2C_CR1(i2c) & ~I2C_CR1_DNF_MASK) | dnf_setting; +} + +/* t_presc= (presc+1)*t_i2cclk */ +void i2c_set_prescaler(uint32_t i2c, uint8_t presc) +{ + I2C_TIMINGR(i2c) = (I2C_TIMINGR(i2c) & ~I2C_TIMINGR_PRESC_MASK) | + (presc << I2C_TIMINGR_PRESC_SHIFT); +} + +void i2c_set_data_setup_time(uint32_t i2c, uint8_t s_time) +{ + I2C_TIMINGR(i2c) = (I2C_TIMINGR(i2c) & ~I2C_TIMINGR_SCLDEL_MASK) | + (s_time << I2C_TIMINGR_SCLDEL_SHIFT); +} + +void i2c_set_data_hold_time(uint32_t i2c, uint8_t h_time) +{ + I2C_TIMINGR(i2c) = (I2C_TIMINGR(i2c) & ~I2C_TIMINGR_SDADEL_MASK) | + (h_time << I2C_TIMINGR_SDADEL_SHIFT); +} + +void i2c_set_scl_high_period(uint32_t i2c, uint8_t period) +{ + I2C_TIMINGR(i2c) = (I2C_TIMINGR(i2c) & ~I2C_TIMINGR_SCLH_MASK) | + (period << I2C_TIMINGR_SCLH_SHIFT); +} + +void i2c_set_scl_low_period(uint32_t i2c, uint8_t period) +{ + I2C_TIMINGR(i2c) = (I2C_TIMINGR(i2c) & ~I2C_TIMINGR_SCLL_MASK) | + (period << I2C_TIMINGR_SCLL_SHIFT); +} + +void i2c_enable_stretching(uint32_t i2c) +{ + I2C_CR1(i2c) &= ~I2C_CR1_NOSTRETCH; +} + +void i2c_disable_stretching(uint32_t i2c) +{ + I2C_CR1(i2c) |= I2C_CR1_NOSTRETCH; +} + +void i2c_100khz_i2cclk8mhz(uint32_t i2c) +{ + i2c_set_prescaler(i2c, 1); + i2c_set_scl_low_period(i2c, 0x13); + i2c_set_scl_high_period(i2c, 0xF); + i2c_set_data_hold_time(i2c, 0x2); + i2c_set_data_setup_time(i2c, 0x4); +} + +void i2c_set_7bit_addr_mode(uint32_t i2c) +{ + I2C_CR2(i2c) &= ~I2C_CR2_ADD10; +} + +void i2c_set_10bit_addr_mode(uint32_t i2c) +{ + I2C_CR2(i2c) |= I2C_CR2_ADD10; +} + +void i2c_set_7bit_address(uint32_t i2c, uint8_t addr) +{ + I2C_CR2(i2c) = (I2C_CR2(i2c) & ~I2C_CR2_SADD_7BIT_MASK) | + ((addr & 0x7F) << I2C_CR2_SADD_7BIT_SHIFT); +} + +void i2c_set_10bit_address(uint32_t i2c, uint16_t addr) +{ + I2C_CR2(i2c) = (I2C_CR2(i2c) & ~I2C_CR2_SADD_10BIT_MASK) | + ((addr & 0x3FF) << I2C_CR2_SADD_10BIT_SHIFT); +} + +void i2c_set_write_transfer_dir(uint32_t i2c) +{ + I2C_CR2(i2c) &= ~I2C_CR2_RD_WRN; +} + +void i2c_set_read_transfer_dir(uint32_t i2c) +{ + I2C_CR2(i2c) |= I2C_CR2_RD_WRN; +} + +void i2c_set_bytes_to_transfer(uint32_t i2c, uint32_t n_bytes) +{ + I2C_CR2(i2c) = (I2C_CR2(i2c) & ~I2C_CR2_NBYTES_MASK) | + (n_bytes << I2C_CR2_NBYTES_SHIFT); +} + +uint8_t i2c_is_start(uint32_t i2c) +{ + if ((I2C_CR2(i2c) & I2C_CR2_START) != 0) { + return 1; + } + + return 0; +} + +void i2c_enable_autoend(uint32_t i2c) +{ + I2C_CR2(i2c) |= I2C_CR2_AUTOEND; +} + +void i2c_disable_autoend(uint32_t i2c) +{ + I2C_CR2(i2c) &= ~I2C_CR2_AUTOEND; +} + +uint8_t i2c_nack(uint32_t i2c) +{ + if ((I2C_ISR(i2c) & I2C_ISR_NACKF) != 0) { + return 1; + } + + return 0; +} + +uint8_t i2c_busy(uint32_t i2c) +{ + if ((I2C_ISR(i2c) & I2C_ISR_BUSY) != 0) { + return 1; + } + + return 0; +} + +uint8_t i2c_transmit_int_status(uint32_t i2c) +{ + if ((I2C_ISR(i2c) & I2C_ISR_TXIS) != 0) { + return 1; + } + + return 0; +} + +uint8_t i2c_transfer_complete(uint32_t i2c) +{ + if ((I2C_ISR(i2c) & I2C_ISR_TC) != 0) { + return 1; + } + + return 0; +} + +uint8_t i2c_received_data(uint32_t i2c) +{ + if ((I2C_ISR(i2c) & I2C_ISR_RXNE) != 0) { + return 1; + } + + return 0; +} + + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Enable Interrupt + * + * @param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. + * @param[in] interrupt Unsigned int32. Interrupt to enable. + */ +void i2c_enable_interrupt(uint32_t i2c, uint32_t interrupt) +{ + I2C_CR1(i2c) |= interrupt; +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Disable Interrupt + * + * @param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. + * @param[in] interrupt Unsigned int32. Interrupt to disable. + */ +void i2c_disable_interrupt(uint32_t i2c, uint32_t interrupt) +{ + I2C_CR1(i2c) &= ~interrupt; +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Enable reception DMA + * + * @param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. + */ +void i2c_enable_rxdma(uint32_t i2c) +{ + I2C_CR1(i2c) |= I2C_CR1_RXDMAEN; +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Disable reception DMA + * + * @param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. + */ +void i2c_disable_rxdma(uint32_t i2c) +{ + I2C_CR1(i2c) &= ~I2C_CR1_RXDMAEN; +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Enable transmission DMA + * + * @param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. + */ +void i2c_enable_txdma(uint32_t i2c) +{ + I2C_CR1(i2c) |= I2C_CR1_TXDMAEN; +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Disable transmission DMA + * + * @param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. + */ +void i2c_disable_txdma(uint32_t i2c) +{ + I2C_CR1(i2c) &= ~I2C_CR1_TXDMAEN; +} + +void write_i2c(uint32_t i2c, uint8_t i2c_addr, uint8_t reg, uint8_t size, + uint8_t *data) +{ + int wait; + int i; + while (i2c_busy(i2c) == 1); + while (i2c_is_start(i2c) == 1); + /*Setting transfer properties*/ + i2c_set_bytes_to_transfer(i2c, size + 1); + i2c_set_7bit_address(i2c, (i2c_addr & 0x7F)); + i2c_set_write_transfer_dir(i2c); + i2c_enable_autoend(i2c); + /*start transfer*/ + i2c_send_start(i2c); + + wait = true; + while (wait) { + if (i2c_transmit_int_status(i2c)) { + wait = false; + } + while (i2c_nack(i2c)); + } + + i2c_send_data(i2c, reg); + for (i = 0; i < size; i++) { + wait = true; + while (wait) { + if (i2c_transmit_int_status(i2c)) { + wait = false; + } + while (i2c_nack(i2c)); + } + i2c_send_data(i2c, data[i]); + } +} + +void read_i2c(uint32_t i2c, uint8_t i2c_addr, uint8_t reg, uint8_t size, + uint8_t *data) +{ + int wait; + int i; + while (i2c_busy(i2c) == 1); + while (i2c_is_start(i2c) == 1); + /*Setting transfer properties*/ + i2c_set_bytes_to_transfer(i2c, 1); + i2c_set_7bit_address(i2c, i2c_addr); + i2c_set_write_transfer_dir(i2c); + i2c_disable_autoend(i2c); + /*start transfer*/ + i2c_send_start(i2c); + + wait = true; + while (wait) { + if (i2c_transmit_int_status(i2c)) { + wait = false; + } + while (i2c_nack(i2c)); /* Some error */ + } + i2c_send_data(i2c, reg); + + while (i2c_is_start(i2c) == 1); + /*Setting transfer properties*/ + i2c_set_bytes_to_transfer(i2c, size); + i2c_set_7bit_address(i2c, i2c_addr); + i2c_set_read_transfer_dir(i2c); + i2c_enable_autoend(i2c); + /*start transfer*/ + i2c_send_start(i2c); + + for (i = 0; i < size; i++) { + while (i2c_received_data(i2c) == 0); + data[i] = i2c_get_data(i2c); + } +} + +/**@}*/ |