diff options
Diffstat (limited to 'libmaple/stm32f1/dma.c')
| -rw-r--r-- | libmaple/stm32f1/dma.c | 371 |
1 files changed, 371 insertions, 0 deletions
diff --git a/libmaple/stm32f1/dma.c b/libmaple/stm32f1/dma.c new file mode 100644 index 0000000..14ac645 --- /dev/null +++ b/libmaple/stm32f1/dma.c @@ -0,0 +1,371 @@ +/****************************************************************************** + * The MIT License + * + * Copyright (c) 2010 Michael Hope. + * Copyright (c) 2012 LeafLabs, LLC. + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + *****************************************************************************/ + +/** + * @file libmaple/stm32f1/dma.c + * @author Marti Bolivar <mbolivar@leaflabs.com>; + * Original implementation by Michael Hope + * @brief STM32F1 DMA support. + */ + +#include <libmaple/dma.h> +#include <libmaple/bitband.h> + +/* + * Devices + */ + +static dma_dev dma1 = { + .regs = DMA1_BASE, + .clk_id = RCC_DMA1, + .handlers = {{ .handler = NULL, .irq_line = NVIC_DMA_CH1 }, + { .handler = NULL, .irq_line = NVIC_DMA_CH2 }, + { .handler = NULL, .irq_line = NVIC_DMA_CH3 }, + { .handler = NULL, .irq_line = NVIC_DMA_CH4 }, + { .handler = NULL, .irq_line = NVIC_DMA_CH5 }, + { .handler = NULL, .irq_line = NVIC_DMA_CH6 }, + { .handler = NULL, .irq_line = NVIC_DMA_CH7 }}, +}; +/** DMA1 device */ +dma_dev *DMA1 = &dma1; + +#if defined(STM32_HIGH_DENSITY) || defined(STM32_XL_DENSITY) +static dma_dev dma2 = { + .regs = DMA2_BASE, + .clk_id = RCC_DMA2, + .handlers = {{ .handler = NULL, .irq_line = NVIC_DMA2_CH1 }, + { .handler = NULL, .irq_line = NVIC_DMA2_CH2 }, + { .handler = NULL, .irq_line = NVIC_DMA2_CH3 }, + { .handler = NULL, .irq_line = NVIC_DMA2_CH_4_5 }, + { .handler = NULL, .irq_line = NVIC_DMA2_CH_4_5 }}, /* !@#$ */ +}; +/** DMA2 device */ +dma_dev *DMA2 = &dma2; +#endif + +/* + * Routines + */ + +/** + * @brief Set up a DMA transfer. + * + * The channel will be disabled before being reconfigured. The + * transfer will have low priority by default. You may choose another + * priority before the transfer begins using dma_set_priority(), as + * well as performing any other configuration you desire. When the + * channel is configured to your liking, enable it using dma_enable(). + * + * @param dev DMA device. + * @param channel DMA channel. + * @param peripheral_address Base address of peripheral data register + * involved in the transfer. + * @param peripheral_size Peripheral data transfer size. + * @param memory_address Base memory address involved in the transfer. + * @param memory_size Memory data transfer size. + * @param mode Logical OR of dma_mode_flags + * @sideeffect Disables the given DMA channel. + * @see dma_xfer_size + * @see dma_mode_flags + * @see dma_set_num_transfers() + * @see dma_set_priority() + * @see dma_attach_interrupt() + * @see dma_enable() + */ +void dma_setup_transfer(dma_dev *dev, + dma_channel channel, + __io void *peripheral_address, + dma_xfer_size peripheral_size, + __io void *memory_address, + dma_xfer_size memory_size, + uint32 mode) { + dma_channel_reg_map *channel_regs = dma_channel_regs(dev, channel); + + dma_disable(dev, channel); /* can't write to CMAR/CPAR otherwise */ + channel_regs->CCR = (memory_size << 10) | (peripheral_size << 8) | mode; + channel_regs->CMAR = (uint32)memory_address; + channel_regs->CPAR = (uint32)peripheral_address; +} + +/** + * @brief Set the number of data to be transferred on a DMA channel. + * + * You may not call this function while the channel is enabled. + * + * @param dev DMA device + * @param channel Channel through which the transfer occurs. + * @param num_transfers + */ +void dma_set_num_transfers(dma_dev *dev, + dma_channel channel, + uint16 num_transfers) { + dma_channel_reg_map *channel_regs; + + ASSERT_FAULT(!dma_is_channel_enabled(dev, channel)); + + channel_regs = dma_channel_regs(dev, channel); + channel_regs->CNDTR = num_transfers; +} + +/** + * @brief Set the priority of a DMA transfer. + * + * You may not call this function while the channel is enabled. + * + * @param dev DMA device + * @param channel DMA channel + * @param priority priority to set. + */ +void dma_set_priority(dma_dev *dev, + dma_channel channel, + dma_priority priority) { + dma_channel_reg_map *channel_regs; + uint32 ccr; + + ASSERT_FAULT(!dma_is_channel_enabled(dev, channel)); + + channel_regs = dma_channel_regs(dev, channel); + ccr = channel_regs->CCR; + ccr &= ~DMA_CCR_PL; + ccr |= priority; + channel_regs->CCR = ccr; +} + +/** + * @brief Attach an interrupt to a DMA transfer. + * + * Interrupts are enabled using appropriate mode flags in + * dma_setup_transfer(). + * + * @param dev DMA device + * @param channel Channel to attach handler to + * @param handler Interrupt handler to call when channel interrupt fires. + * @see dma_setup_transfer() + * @see dma_get_irq_cause() + * @see dma_detach_interrupt() + */ +void dma_attach_interrupt(dma_dev *dev, + dma_channel channel, + void (*handler)(void)) { + dev->handlers[channel - 1].handler = handler; + nvic_irq_enable(dev->handlers[channel - 1].irq_line); +} + +/** + * @brief Detach a DMA transfer interrupt handler. + * + * After calling this function, the given channel's interrupts will be + * disabled. + * + * @param dev DMA device + * @param channel Channel whose handler to detach + * @sideeffect Clears interrupt enable bits in the channel's CCR register. + * @see dma_attach_interrupt() + */ +void dma_detach_interrupt(dma_dev *dev, dma_channel channel) { + /* Don't use nvic_irq_disable()! Think about DMA2 channels 4 and 5. */ + dma_channel_regs(dev, channel)->CCR &= ~0xF; + dev->handlers[channel - 1].handler = NULL; +} + +/** + * @brief Discover the reason why a DMA interrupt was called. + * + * You may only call this function within an attached interrupt + * handler for the given channel. + * + * This function resets the internal DMA register state which encodes + * the cause of the interrupt; consequently, it can only be called + * once per interrupt handler invocation. + * + * @param dev DMA device + * @param channel Channel whose interrupt is being handled. + * @return Reason why the interrupt fired. + * @sideeffect Clears channel status flags in dev->regs->ISR. + * @see dma_attach_interrupt() + * @see dma_irq_cause + */ +dma_irq_cause dma_get_irq_cause(dma_dev *dev, dma_channel channel) { + uint8 status_bits = dma_get_isr_bits(dev, channel); + + /* If the channel global interrupt flag is cleared, then + * something's very wrong. */ + ASSERT(status_bits & BIT(0)); + + dma_clear_isr_bits(dev, channel); + + /* ISR flags get set even if the corresponding interrupt enable + * bits in the channel's configuration register are cleared, so we + * can't use a switch here. + * + * Don't change the order of these if statements. */ + if (status_bits & BIT(3)) { + return DMA_TRANSFER_ERROR; + } else if (status_bits & BIT(1)) { + return DMA_TRANSFER_COMPLETE; + } else if (status_bits & BIT(2)) { + return DMA_TRANSFER_HALF_COMPLETE; + } else if (status_bits & BIT(0)) { + /* Shouldn't happen (unless someone messed up an IFCR write). */ + throb(); + } +#if DEBUG_LEVEL < DEBUG_ALL + else { + /* We shouldn't have been called, but the debug level is too + * low for the above ASSERT() to have had any effect. In + * order to fail fast, mimic the DMA controller's behavior + * when an error occurs. */ + dma_disable(dev, channel); + } +#endif + return DMA_TRANSFER_ERROR; +} + +/** + * @brief Enable a DMA channel. + * @param dev DMA device + * @param channel Channel to enable + */ +void dma_enable(dma_dev *dev, dma_channel channel) { + dma_channel_reg_map *chan_regs = dma_channel_regs(dev, channel); + bb_peri_set_bit(&chan_regs->CCR, DMA_CCR_EN_BIT, 1); +} + +/** + * @brief Disable a DMA channel. + * @param dev DMA device + * @param channel Channel to disable + */ +void dma_disable(dma_dev *dev, dma_channel channel) { + dma_channel_reg_map *chan_regs = dma_channel_regs(dev, channel); + bb_peri_set_bit(&chan_regs->CCR, DMA_CCR_EN_BIT, 0); +} + +/** + * @brief Set the base memory address where data will be read from or + * written to. + * + * You must not call this function while the channel is enabled. + * + * If the DMA memory size is 16 bits, the address is automatically + * aligned to a half-word. If the DMA memory size is 32 bits, the + * address is aligned to a word. + * + * @param dev DMA Device + * @param channel Channel whose base memory address to set. + * @param addr Memory base address to use. + */ +void dma_set_mem_addr(dma_dev *dev, dma_channel channel, __io void *addr) { + dma_channel_reg_map *chan_regs; + + ASSERT_FAULT(!dma_is_channel_enabled(dev, channel)); + + chan_regs = dma_channel_regs(dev, channel); + chan_regs->CMAR = (uint32)addr; +} + +/** + * @brief Set the base peripheral address where data will be read from + * or written to. + * + * You must not call this function while the channel is enabled. + * + * If the DMA peripheral size is 16 bits, the address is automatically + * aligned to a half-word. If the DMA peripheral size is 32 bits, the + * address is aligned to a word. + * + * @param dev DMA Device + * @param channel Channel whose peripheral data register base address to set. + * @param addr Peripheral memory base address to use. + */ +void dma_set_per_addr(dma_dev *dev, dma_channel channel, __io void *addr) { + dma_channel_reg_map *chan_regs; + + ASSERT_FAULT(!dma_is_channel_enabled(dev, channel)); + + chan_regs = dma_channel_regs(dev, channel); + chan_regs->CPAR = (uint32)addr; +} + +/* + * IRQ handlers + */ + +static __always_inline void dispatch_handler(dma_dev *dev, int channel) { + void (*handler)(void) = dev->handlers[channel - 1].handler; + if (handler) { + handler(); + dma_clear_isr_bits(dev, channel); /* in case handler doesn't */ + } +} + +void __irq_dma1_channel1(void) { + dispatch_handler(DMA1, DMA_CH1); +} + +void __irq_dma1_channel2(void) { + dispatch_handler(DMA1, DMA_CH2); +} + +void __irq_dma1_channel3(void) { + dispatch_handler(DMA1, DMA_CH3); +} + +void __irq_dma1_channel4(void) { + dispatch_handler(DMA1, DMA_CH4); +} + +void __irq_dma1_channel5(void) { + dispatch_handler(DMA1, DMA_CH5); +} + +void __irq_dma1_channel6(void) { + dispatch_handler(DMA1, DMA_CH6); +} + +void __irq_dma1_channel7(void) { + dispatch_handler(DMA1, DMA_CH7); +} + +#ifdef STM32_HIGH_DENSITY +void __irq_dma2_channel1(void) { + dispatch_handler(DMA2, DMA_CH1); +} + +void __irq_dma2_channel2(void) { + dispatch_handler(DMA2, DMA_CH2); +} + +void __irq_dma2_channel3(void) { + dispatch_handler(DMA2, DMA_CH3); +} + +void __irq_dma2_channel4_5(void) { + dispatch_handler(DMA2, DMA_CH4); + dispatch_handler(DMA2, DMA_CH5); +} +#endif |