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Diffstat (limited to 'libopencm3/lib/stm32/common/i2c_common_all.c')
-rw-r--r-- | libopencm3/lib/stm32/common/i2c_common_all.c | 419 |
1 files changed, 419 insertions, 0 deletions
diff --git a/libopencm3/lib/stm32/common/i2c_common_all.c b/libopencm3/lib/stm32/common/i2c_common_all.c new file mode 100644 index 0000000..886f594 --- /dev/null +++ b/libopencm3/lib/stm32/common/i2c_common_all.c @@ -0,0 +1,419 @@ +/** @addtogroup i2c_file + +@author @htmlonly © @endhtmlonly 2010 +Thomas Otto <tommi@viadmin.org> +@author @htmlonly © @endhtmlonly 2012 +Ken Sarkies <ksarkies@internode.on.net> + +Devices can have up to three I2C peripherals. The peripherals support SMBus and +PMBus variants. + +A peripheral begins after reset in Slave mode. To become a Master a start +condition must be generated. The peripheral will remain in Master mode unless +a multimaster contention is lost or a stop condition is generated. + +@todo all sorts of lovely stuff like DMA, Interrupts, SMBus variant, Status +register access, Error conditions + +*/ +/* + * This file is part of the libopencm3 project. + * + * Copyright (C) 2010 Thomas Otto <tommi@viadmin.org> + * + * 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_periph_reset_pulse(RST_I2C1); + break; +#if defined(I2C2_BASE) + case I2C2: + rcc_periph_reset_pulse(RST_I2C2); + break; +#endif +#if defined(I2C3_BASE) + case I2C3: + rcc_periph_reset_pulse(RST_I2C3); + break; +#endif + default: + 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_CR1(i2c) |= I2C_CR1_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_CR1(i2c) |= I2C_CR1_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_CR1(i2c) &= ~I2C_CR1_STOP; +} + +/*---------------------------------------------------------------------------*/ +/** @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_ADDMODE; + 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_ADDMODE | slave); +} + + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Set Peripheral Clock Frequency. + +Set the peripheral clock frequency: 2MHz to 36MHz (the APB frequency). Note +that this is <b> not </b> the I2C bus clock. This is set in conjunction with +the Clock Control register to generate the Master bus clock, see @ref +i2c_set_ccr + +@param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. +@param[in] freq Unsigned int8. Clock Frequency Setting @ref i2c_clock. +*/ + +void i2c_set_clock_frequency(uint32_t i2c, uint8_t freq) +{ + uint16_t reg16; + reg16 = I2C_CR2(i2c) & 0xffc0; /* Clear bits [5:0]. */ + reg16 |= freq; + I2C_CR2(i2c) = reg16; +} + +/*---------------------------------------------------------------------------*/ +/** @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_DR(i2c) = data; +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Set Fast Mode. + +Set the clock frequency to the high clock rate mode (up to 400kHz). The actual +clock frequency must be set with @ref i2c_set_clock_frequency + +@param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. +*/ + +void i2c_set_fast_mode(uint32_t i2c) +{ + I2C_CCR(i2c) |= I2C_CCR_FS; +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Set Standard Mode. + +Set the clock frequency to the standard clock rate mode (up to 100kHz). The +actual clock frequency must be set with @ref i2c_set_clock_frequency + +@param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. +*/ + +void i2c_set_standard_mode(uint32_t i2c) +{ + I2C_CCR(i2c) &= ~I2C_CCR_FS; +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Set Bus Clock Frequency. + +Set the bus clock frequency. This is a 12 bit number (0...4095) calculated +from the formulae given in the STM32F1 reference manual in the description +of the CCR field. It is a divisor of the peripheral clock frequency +@ref i2c_set_clock_frequency modified by the fast mode setting +@ref i2c_set_fast_mode + +@todo provide additional API assitance to set the clock, eg macros + +@param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. +@param[in] freq Unsigned int16. Bus Clock Frequency Setting 0...4095. +*/ + +void i2c_set_ccr(uint32_t i2c, uint16_t freq) +{ + uint16_t reg16; + reg16 = I2C_CCR(i2c) & 0xf000; /* Clear bits [11:0]. */ + reg16 |= freq; + I2C_CCR(i2c) = reg16; +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Set the Rise Time. + +Set the maximum rise time on the bus according to the I2C specification, as 1 +more than the specified rise time in peripheral clock cycles. This is a 6 bit +number. + +@todo provide additional APIP assistance. + +@param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. +@param[in] trise Unsigned int16. Rise Time Setting 0...63. +*/ + +void i2c_set_trise(uint32_t i2c, uint16_t trise) +{ + I2C_TRISE(i2c) = trise; +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Send the 7-bit Slave Address. + +@param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. +@param[in] slave Unsigned int16. Slave address 0...1023. +@param[in] readwrite Unsigned int8. Single bit to instruct slave to receive or +send @ref i2c_rw. +*/ + +void i2c_send_7bit_address(uint32_t i2c, uint8_t slave, uint8_t readwrite) +{ + I2C_DR(i2c) = (uint8_t)((slave << 1) | readwrite); +} + +/*---------------------------------------------------------------------------*/ +/** @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_DR(i2c) & 0xff; +} + +/*---------------------------------------------------------------------------*/ +/** @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_CR2(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_CR2(i2c) &= ~interrupt; +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Enable ACK + +Enables acking of own 7/10 bit address +@param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. +*/ +void i2c_enable_ack(uint32_t i2c) +{ + I2C_CR1(i2c) |= I2C_CR1_ACK; +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Disable ACK + +Disables acking of own 7/10 bit address +@param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. +*/ +void i2c_disable_ack(uint32_t i2c) +{ + I2C_CR1(i2c) &= ~I2C_CR1_ACK; +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C NACK Next Byte + +Causes the I2C controller to NACK the reception of the next byte +@param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. +*/ +void i2c_nack_next(uint32_t i2c) +{ + I2C_CR1(i2c) |= I2C_CR1_POS; +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C NACK Next Byte + +Causes the I2C controller to NACK the reception of the current byte + +@param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. +*/ +void i2c_nack_current(uint32_t i2c) +{ + I2C_CR1(i2c) &= ~I2C_CR1_POS; +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Set clock duty cycle + +@param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. +@param[in] dutycycle Unsigned int32. I2C duty cycle @ref i2c_duty_cycle. +*/ +void i2c_set_dutycycle(uint32_t i2c, uint32_t dutycycle) +{ + if (dutycycle == I2C_CCR_DUTY_DIV2) { + I2C_CCR(i2c) &= ~I2C_CCR_DUTY; + } else { + I2C_CCR(i2c) |= I2C_CCR_DUTY; + } +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Enable DMA + +@param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. +*/ +void i2c_enable_dma(uint32_t i2c) +{ + I2C_CR2(i2c) |= I2C_CR2_DMAEN; +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Disable DMA + +@param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. +*/ +void i2c_disable_dma(uint32_t i2c) +{ + I2C_CR2(i2c) &= ~I2C_CR2_DMAEN; +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Set DMA last transfer + +@param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. +*/ +void i2c_set_dma_last_transfer(uint32_t i2c) +{ + I2C_CR2(i2c) |= I2C_CR2_LAST; +} + +/*---------------------------------------------------------------------------*/ +/** @brief I2C Clear DMA last transfer + +@param[in] i2c Unsigned int32. I2C register base address @ref i2c_reg_base. +*/ +void i2c_clear_dma_last_transfer(uint32_t i2c) +{ + I2C_CR2(i2c) &= ~I2C_CR2_LAST; +} + +/**@}*/ |