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Diffstat (limited to 'libopencm3/lib/stm32/common/usart_common_all.c')
| -rw-r--r-- | libopencm3/lib/stm32/common/usart_common_all.c | 367 |
1 files changed, 367 insertions, 0 deletions
diff --git a/libopencm3/lib/stm32/common/usart_common_all.c b/libopencm3/lib/stm32/common/usart_common_all.c new file mode 100644 index 0000000..43fd199 --- /dev/null +++ b/libopencm3/lib/stm32/common/usart_common_all.c @@ -0,0 +1,367 @@ +/** @addtogroup usart_file + +@author @htmlonly © @endhtmlonly 2009 Uwe Hermann <uwe@hermann-uwe.de> + +This library supports the USART/UART in the STM32F series +of ARM Cortex Microcontrollers by ST Microelectronics. + +Devices can have up to 3 USARTs and 2 UARTs. + +*/ + +/* + * This file is part of the libopencm3 project. + * + * Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de> + * + * 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/usart.h> +#include <libopencm3/stm32/rcc.h> + +/*---------------------------------------------------------------------------*/ +/** @brief USART Set Baudrate. + +The baud rate is computed from the APB high-speed prescaler clock (for +USART1/6) or the APB low-speed prescaler clock (for other USARTs). These values +must be correctly set before calling this function (refer to the +rcc_clock_setup-* functions in RCC). + +@param[in] usart unsigned 32 bit. USART block register address base @ref +usart_reg_base +@param[in] baud unsigned 32 bit. Baud rate specified in Hz. +*/ + +void usart_set_baudrate(uint32_t usart, uint32_t baud) +{ + uint32_t clock = rcc_ppre1_frequency; + +#if defined STM32F2 || defined STM32F4 + if ((usart == USART1) || + (usart == USART6)) { + clock = rcc_ppre2_frequency; + } +#else + if (usart == USART1) { + clock = rcc_ppre2_frequency; + } +#endif + + /* + * Yes it is as simple as that. The reference manual is + * talking about fractional calculation but it seems to be only + * marketting babble to sound awesome. It is nothing else but a + * simple divider to generate the correct baudrate. + * + * Note: We round() the value rather than floor()ing it, for more + * accurate divisor selection. + */ + USART_BRR(usart) = ((2 * clock) + baud) / (2 * baud); +} + +/*---------------------------------------------------------------------------*/ +/** @brief USART Set Word Length. + +The word length is set to 8 or 9 bits. Note that the last bit will be a parity +bit if parity is enabled, in which case the data length will be 7 or 8 bits +respectively. + +@param[in] usart unsigned 32 bit. USART block register address base @ref +usart_reg_base +@param[in] bits unsigned 32 bit. Word length in bits 8 or 9. +*/ + +void usart_set_databits(uint32_t usart, uint32_t bits) +{ + if (bits == 8) { + USART_CR1(usart) &= ~USART_CR1_M; /* 8 data bits */ + } else { + USART_CR1(usart) |= USART_CR1_M; /* 9 data bits */ + } +} + +/*---------------------------------------------------------------------------*/ +/** @brief USART Set Stop Bit(s). + +The stop bits are specified as 0.5, 1, 1.5 or 2. + +@param[in] usart unsigned 32 bit. USART block register address base @ref +usart_reg_base +@param[in] stopbits unsigned 32 bit. Stop bits @ref usart_cr2_stopbits. +*/ + +void usart_set_stopbits(uint32_t usart, uint32_t stopbits) +{ + uint32_t reg32; + + reg32 = USART_CR2(usart); + reg32 = (reg32 & ~USART_CR2_STOPBITS_MASK) | stopbits; + USART_CR2(usart) = reg32; +} + +/*---------------------------------------------------------------------------*/ +/** @brief USART Set Parity. + +The parity bit can be selected as none, even or odd. + +@param[in] usart unsigned 32 bit. USART block register address base @ref +usart_reg_base +@param[in] parity unsigned 32 bit. Parity @ref usart_cr1_parity. +*/ + +void usart_set_parity(uint32_t usart, uint32_t parity) +{ + uint32_t reg32; + + reg32 = USART_CR1(usart); + reg32 = (reg32 & ~USART_PARITY_MASK) | parity; + USART_CR1(usart) = reg32; +} + +/*---------------------------------------------------------------------------*/ +/** @brief USART Set Rx/Tx Mode. + +The mode can be selected as Rx only, Tx only or Rx+Tx. + +@param[in] usart unsigned 32 bit. USART block register address base @ref +usart_reg_base +@param[in] mode unsigned 32 bit. Mode @ref usart_cr1_mode. +*/ + +void usart_set_mode(uint32_t usart, uint32_t mode) +{ + uint32_t reg32; + + reg32 = USART_CR1(usart); + reg32 = (reg32 & ~USART_MODE_MASK) | mode; + USART_CR1(usart) = reg32; +} + +/*---------------------------------------------------------------------------*/ +/** @brief USART Set Hardware Flow Control. + +The flow control bit can be selected as none, RTS, CTS or RTS+CTS. + +@param[in] usart unsigned 32 bit. USART block register address base @ref +usart_reg_base +@param[in] flowcontrol unsigned 32 bit. Flowcontrol @ref usart_cr3_flowcontrol. +*/ + +void usart_set_flow_control(uint32_t usart, uint32_t flowcontrol) +{ + uint32_t reg32; + + reg32 = USART_CR3(usart); + reg32 = (reg32 & ~USART_FLOWCONTROL_MASK) | flowcontrol; + USART_CR3(usart) = reg32; +} + +/*---------------------------------------------------------------------------*/ +/** @brief USART Enable. + +@param[in] usart unsigned 32 bit. USART block register address base @ref +usart_reg_base +*/ + +void usart_enable(uint32_t usart) +{ + USART_CR1(usart) |= USART_CR1_UE; +} + +/*---------------------------------------------------------------------------*/ +/** @brief USART Disable. + +At the end of the current frame, the USART is disabled to reduce power. + +@param[in] usart unsigned 32 bit. USART block register address base @ref +usart_reg_base +*/ + +void usart_disable(uint32_t usart) +{ + USART_CR1(usart) &= ~USART_CR1_UE; +} + +/*---------------------------------------------------------------------------*/ +/** @brief USART Send Data Word with Blocking + +Blocks until the transmit data buffer becomes empty then writes the next data +word for transmission. + +@param[in] usart unsigned 32 bit. USART block register address base @ref +usart_reg_base +@param[in] data unsigned 16 bit. +*/ + +void usart_send_blocking(uint32_t usart, uint16_t data) +{ + usart_wait_send_ready(usart); + usart_send(usart, data); +} + +/*---------------------------------------------------------------------------*/ +/** @brief USART Read a Received Data Word with Blocking. + +Wait until a data word has been received then return the word. + +@param[in] usart unsigned 32 bit. USART block register address base @ref +usart_reg_base +@returns unsigned 16 bit data word. +*/ + +uint16_t usart_recv_blocking(uint32_t usart) +{ + usart_wait_recv_ready(usart); + + return usart_recv(usart); +} + +/*---------------------------------------------------------------------------*/ +/** @brief USART Receiver DMA Enable. + +DMA is available on: +@li USART1 Rx DMA1 channel 5. +@li USART2 Rx DMA1 channel 6. +@li USART3 Rx DMA1 channel 3. +@li UART4 Rx DMA2 channel 3. + +@param[in] usart unsigned 32 bit. USART block register address base @ref +usart_reg_base +*/ + +void usart_enable_rx_dma(uint32_t usart) +{ + USART_CR3(usart) |= USART_CR3_DMAR; +} + +/*---------------------------------------------------------------------------*/ +/** @brief USART Receiver DMA Disable. + +@param[in] usart unsigned 32 bit. USART block register address base @ref +usart_reg_base +*/ + +void usart_disable_rx_dma(uint32_t usart) +{ + USART_CR3(usart) &= ~USART_CR3_DMAR; +} + +/*---------------------------------------------------------------------------*/ +/** @brief USART Transmitter DMA Enable. + +DMA is available on: +@li USART1 Tx DMA1 channel 4. +@li USART2 Tx DMA1 channel 7. +@li USART3 Tx DMA1 channel 2. +@li UART4 Tx DMA2 channel 5. + +@param[in] usart unsigned 32 bit. USART block register address base @ref +usart_reg_base +*/ + +void usart_enable_tx_dma(uint32_t usart) +{ + USART_CR3(usart) |= USART_CR3_DMAT; +} + +/*---------------------------------------------------------------------------*/ +/** @brief USART Transmitter DMA Disable. + +@param[in] usart unsigned 32 bit. USART block register address base @ref +usart_reg_base +*/ + +void usart_disable_tx_dma(uint32_t usart) +{ + USART_CR3(usart) &= ~USART_CR3_DMAT; +} + +/*---------------------------------------------------------------------------*/ +/** @brief USART Receiver Interrupt Enable. + +@param[in] usart unsigned 32 bit. USART block register address base @ref +usart_reg_base +*/ + +void usart_enable_rx_interrupt(uint32_t usart) +{ + USART_CR1(usart) |= USART_CR1_RXNEIE; +} + + +/*---------------------------------------------------------------------------*/ +/** @brief USART Receiver Interrupt Disable. + +@param[in] usart unsigned 32 bit. USART block register address base @ref +usart_reg_base +*/ + +void usart_disable_rx_interrupt(uint32_t usart) +{ + USART_CR1(usart) &= ~USART_CR1_RXNEIE; +} + +/*---------------------------------------------------------------------------*/ +/** @brief USART Transmitter Interrupt Enable. + +@param[in] usart unsigned 32 bit. USART block register address base @ref +usart_reg_base +*/ + +void usart_enable_tx_interrupt(uint32_t usart) +{ + USART_CR1(usart) |= USART_CR1_TXEIE; +} + +/*---------------------------------------------------------------------------*/ +/** @brief USART Transmitter Interrupt Disable. + +@param[in] usart unsigned 32 bit. USART block register address base @ref +usart_reg_base +*/ + +void usart_disable_tx_interrupt(uint32_t usart) +{ + USART_CR1(usart) &= ~USART_CR1_TXEIE; +} + +/*---------------------------------------------------------------------------*/ +/** @brief USART Error Interrupt Enable. + +@param[in] usart unsigned 32 bit. USART block register address base @ref +usart_reg_base +*/ + +void usart_enable_error_interrupt(uint32_t usart) +{ + USART_CR3(usart) |= USART_CR3_EIE; +} + +/*---------------------------------------------------------------------------*/ +/** @brief USART Error Interrupt Disable. + +@param[in] usart unsigned 32 bit. USART block register address base @ref +usart_reg_base +*/ + +void usart_disable_error_interrupt(uint32_t usart) +{ + USART_CR3(usart) &= ~USART_CR3_EIE; +} + +/**@}*/ + |