diff options
| -rw-r--r-- | examples/test-usart-dma.cpp | 127 | ||||
| -rw-r--r-- | libmaple/dma.c | 397 | ||||
| -rw-r--r-- | libmaple/dma.h | 445 | ||||
| -rw-r--r-- | libmaple/nvic.h | 1 | ||||
| -rw-r--r-- | notes/dma.txt | 99 |
5 files changed, 921 insertions, 148 deletions
diff --git a/examples/test-usart-dma.cpp b/examples/test-usart-dma.cpp new file mode 100644 index 0000000..b9c03f1 --- /dev/null +++ b/examples/test-usart-dma.cpp @@ -0,0 +1,127 @@ +/** + * @file test-usart-dma.cpp + * @author Marti Bolivar <mbolivar@leaflabs.com> + * + * Simple test of DMA used with a USART receiver. + * + * Configures a USART receiver for use with DMA. Received bytes are + * placed into a buffer, with an interrupt firing when the buffer is + * full. At that point, the USART transmitter will print the contents + * of the byte buffer. The buffer is continually filled and refilled + * in this manner. + * + * This example isn't very robust; don't use it in production. In + * particular, since the buffer keeps filling (DMA_CIRC_MODE is set), + * if you keep typing after filling the buffer, you'll overwrite + * earlier bytes; this may happen before those earlier bytes are done + * printing. + * + * This code is released into the public domain. + */ + +#include "dma.h" +#include "usart.h" +#include "gpio.h" + +#include "wirish.h" + +#define BAUD 9600 + +#define USART USART2 +#define USART_HWSER Serial2 +#define USART_DMA_DEV DMA1 +#define USART_RX_DMA_CHANNEL DMA_CH6 +#define USART_TX BOARD_USART2_TX_PIN +#define USART_RX BOARD_USART2_RX_PIN + +#define BUF_SIZE 8 +uint8 rx_buf[BUF_SIZE]; + +dma_irq_cause irq_cause; + +__io uint32 irq_fired = 0; + +void init_usart(void); +void init_dma_xfer(void); +void rx_dma_irq(void); + +void setup(void) { + pinMode(BOARD_LED_PIN, OUTPUT); + + init_dma_xfer(); + init_usart(); +} + +void loop(void) { + toggleLED(); + delay(100); + + dma_channel_reg_map *ch_regs = dma_channel_regs(USART_DMA_DEV, + USART_RX_DMA_CHANNEL); + if (irq_fired) { + USART_HWSER.println("** IRQ **"); + while (true) + ; + } + USART_HWSER.print("["); + USART_HWSER.print(millis()); + USART_HWSER.print("]\tISR bits: 0x"); + uint8 isr_bits = dma_get_isr_bits(USART_DMA_DEV, USART_RX_DMA_CHANNEL); + USART_HWSER.print((int32)isr_bits, HEX); + USART_HWSER.print("\tCCR: 0x"); + USART_HWSER.print((int64)ch_regs->CCR, HEX); + USART_HWSER.print("\tCNDTR: 0x"); + USART_HWSER.print((int64)ch_regs->CNDTR, HEX); + USART_HWSER.print("\tBuffer contents: "); + for (int i = 0; i < BUF_SIZE; i++) { + USART_HWSER.print('\''); + USART_HWSER.print(rx_buf[i]); + USART_HWSER.print('\''); + if (i < BUF_SIZE - 1) USART_HWSER.print(", "); + } + USART_HWSER.println(); + if (isr_bits == 0x7) { + USART_HWSER.println("** Clearing ISR bits."); + dma_clear_isr_bits(USART_DMA_DEV, USART_RX_DMA_CHANNEL); + } + + irq_fired = 0; +} + +/* Configure USART receiver for use with DMA */ +void init_usart(void) { + USART_HWSER.begin(BAUD); + USART->regs->CR3 = USART_CR3_DMAR; +} + +/* Configure DMA transmission */ +void init_dma_xfer(void) { + dma_init(USART_DMA_DEV); + dma_setup_transfer(USART_DMA_DEV, USART_RX_DMA_CHANNEL, + &USART->regs->DR, DMA_SIZE_8BITS, + rx_buf, DMA_SIZE_8BITS, + (DMA_MINC_MODE | DMA_CIRC_MODE | DMA_TRNS_CMPLT + )); + dma_set_num_transfers(USART_DMA_DEV, USART_RX_DMA_CHANNEL, BUF_SIZE); + // Currently not working: + // dma_attach_interrupt(USART_DMA_DEV, USART_RX_DMA_CHANNEL, rx_dma_irq); + dma_enable(USART_DMA_DEV, USART_RX_DMA_CHANNEL); +} + +void rx_dma_irq(void) { +} + +// Force init to be called *first*, i.e. before static object allocation. +// Otherwise, statically allocated objects that need libmaple may fail. +__attribute__((constructor)) void premain() { + init(); +} + +int main(void) { + setup(); + + while (true) { + loop(); + } + return 0; +} diff --git a/libmaple/dma.c b/libmaple/dma.c index c71e52c..6ddabcc 100644 --- a/libmaple/dma.c +++ b/libmaple/dma.c @@ -23,126 +23,351 @@ *****************************************************************************/ /** - * @file dma.c - * - * @brief Direct Memory Access peripheral support + * @file dma.c + * @author Marti Bolivar <mbolivar@leaflabs.com>; + * Original implementation by Michael Hope + * @brief Direct Memory Access peripheral support */ -#include "libmaple.h" #include "dma.h" -#include "rcc.h" -#include "nvic.h" - -#define DMA_EN BIT(0) - -typedef struct dma_regs { - uint32 CCR; - uint32 CNDTR; - uint32 CPAR; - uint32 CMAR; -} dma_regs; - -typedef struct DMAChannel { - void (*handler)(void); - uint32 irq_line; -} DMAChannel; - -volatile static DMAChannel dma_channels[] = { - { .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 } +#include "bitband.h" +#include "util.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 }} +}; +dma_dev *DMA1 = &dma1; + +#ifdef STM32_HIGH_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 }} /* !@#$ */ }; +dma_dev *DMA2 = &dma2; +#endif -/** Get the base address of the given channel, asserting and returning - * NULL on illegal +/* + * Convenience routines */ -static dma_regs *dma_get_regs(uint8 channel) { - if (channel >= 1 && channel <= 7) { - return (dma_regs *)(DMA1_CCR1 + DMA_CHANNEL_STRIDE * (channel-1)); - } else { - ASSERT(0); - return NULL; - } + +/** + * @brief Initialize a DMA device. + * @param dev Device to initialize. + */ +void dma_init(dma_dev *dev) { + rcc_clk_enable(dev->clk_id); } -/* Zero-based indexing */ -static inline void dispatch_handler(uint8 channel_idx) { - ASSERT(dma_channels[channel_idx].handler); - if (dma_channels[channel_idx].handler) { - (dma_channels[channel_idx].handler)(); - } +/** + * @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; } -void __irq_dma1_channel1(void) { - dispatch_handler(0); +/** + * @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; } -void __irq_dma1_channel2(void) { - dispatch_handler(1); +/** + * @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); } -void __irq_dma2_channel3(void) { - dispatch_handler(2); +/** + * @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 + * @sideffect 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; } -void __irq_dma2_channel4(void) { - dispatch_handler(3); +/** + * @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. + * + * @brief dev DMA device + * @brief 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); + return DMA_TRANSFER_ERROR; + } +#endif } -void __irq_dma2_channel5(void) { - dispatch_handler(4); +/** + * @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); } -void __irq_dma2_channel6(void) { - dispatch_handler(5); +/** + * @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); } -void __irq_dma2_channel7(void) { - dispatch_handler(6); +/** + * @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. + */ +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; } -void dma_init(uint8 channel, volatile void *paddr, - dma_transfer_size psize, dma_transfer_size msize, - int mode) { - volatile dma_regs *regs = dma_get_regs(channel); +/** + * @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. + */ +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)); - if (regs != NULL) { - rcc_clk_enable(RCC_DMA1); + chan_regs = dma_channel_regs(dev, channel); + chan_regs->CPAR = (uint32)addr; +} - regs->CCR = ((0 << 12) /* Low priority */ - | (msize << 10) - | (psize << 8) - | (0 << 0) /* Disabled (until started) */ - | mode); +/* + * IRQ handlers + */ - regs->CPAR = (uint32)paddr; +static inline void dispatch_handler(dma_dev *dev, dma_channel channel) { + void (*handler)(void) = dev->handlers[channel - 1].handler; + if (handler) { + handler(); + dma_clear_isr_bits(dev, channel); /* in case handler doesn't */ } } -void dma_start(uint8 channel, volatile void *buffer, uint16 count) { - volatile dma_regs *regs = dma_get_regs(channel); +void __irq_dma_channel1(void) { + dispatch_handler(DMA1, DMA_CH1); +} - if (regs != NULL) { - regs->CCR &= ~DMA_EN; /* CMAR may not be written with EN set */ - regs->CMAR = (uint32)buffer; - regs->CNDTR = count; +void __irq_dma_channel2(void) { + dispatch_handler(DMA1, DMA_CH2); +} - regs->CCR |= DMA_EN; - } +void __irq_dma_channel3(void) { + dispatch_handler(DMA1, DMA_CH3); } -void dma_attach_interrupt(uint8 channel, voidFuncPtr handler) { - channel--; /* 1-based -> 0-based indexing */ - dma_channels[channel].handler = handler; - nvic_irq_enable(dma_channels[channel].irq_line); +void __irq_dma_channel4(void) { + dispatch_handler(DMA1, DMA_CH4); +} + +void __irq_dma_channel5(void) { + dispatch_handler(DMA1, DMA_CH5); +} + +void __irq_dma_channel6(void) { + dispatch_handler(DMA1, DMA_CH6); +} + +void __irq_dma_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 dma_detach_interrupt(uint8 channel) { - channel--; - nvic_irq_disable(dma_channels[channel].irq_line); - dma_channels[channel].handler = NULL; +void __irq_dma2_channel4_5(void) { + dispatch_handler(DMA2, DMA_CH4); + dispatch_handler(DMA2, DMA_CH5); } +#endif diff --git a/libmaple/dma.h b/libmaple/dma.h index 3417f02..c763672 100644 --- a/libmaple/dma.h +++ b/libmaple/dma.h @@ -23,97 +23,418 @@ *****************************************************************************/ /** - * @file dma.h + * @file dma.h * - * @brief Direct Memory Access peripheral support + * @author Marti Bolivar <mbolivar@leaflabs.com>; + * Original implementation by Michael Hope * - * TODO: add DMA2 support for high-density devices. + * @brief Direct Memory Access peripheral support + */ + +/* + * See /notes/dma.txt for more information. */ #ifndef _DMA_H_ #define _DMA_H_ #include "libmaple_types.h" +#include "rcc.h" +#include "nvic.h" #ifdef __cplusplus extern "C"{ #endif -/** Base address of the DMA1 peripheral */ -#define DMA1_BASE 0x40020000 -/** DMA Interrupt Status Register */ -#define DMA1_ISR (DMA1_BASE + 0x00) -/** DMA Interrupt Flag Clear Register */ -#define DMA1_IFCR (DMA1_BASE + 0x04) -/** DMA Channel Configuration Register */ -#define DMA1_CCR1 (DMA1_BASE + 0x08) -/** DMA Channel Number of Data Register */ -#define DMA1_CNDTR1 (DMA1_BASE + 0x0C) -/** DMA Channel Peripheral Address Register */ -#define DMA1_CPAR1 (DMA1_BASE + 0x10) -/** DMA Channel Memory Address Register */ -#define DMA1_CMAR1 (DMA1_BASE + 0x14) -/** Spacing between channel registers */ -#define DMA_CHANNEL_STRIDE 20 +/* + * Register maps + */ + +/** + * @brief DMA register map type. + * + * Note that DMA controller 2 (register map base pointer DMA2_BASE) + * only supports channels 1--5. + */ +typedef struct dma_reg_map { + __io uint32 ISR; /**< Interrupt status register */ + __io uint32 IFCR; /**< Interrupt flag clear register */ + __io uint32 CCR1; /**< Channel 1 configuration register */ + __io uint32 CNDTR1; /**< Channel 1 number of data register */ + __io uint32 CPAR1; /**< Channel 1 peripheral address register */ + __io uint32 CMAR1; /**< Channel 1 memory address register */ + const uint32 RESERVED1; /**< Reserved. */ + __io uint32 CCR2; /**< Channel 2 configuration register */ + __io uint32 CNDTR2; /**< Channel 2 number of data register */ + __io uint32 CPAR2; /**< Channel 2 peripheral address register */ + __io uint32 CMAR2; /**< Channel 2 memory address register */ + const uint32 RESERVED2; /**< Reserved. */ + __io uint32 CCR3; /**< Channel 3 configuration register */ + __io uint32 CNDTR3; /**< Channel 3 number of data register */ + __io uint32 CPAR3; /**< Channel 3 peripheral address register */ + __io uint32 CMAR3; /**< Channel 3 memory address register */ + const uint32 RESERVED3; /**< Reserved. */ + __io uint32 CCR4; /**< Channel 4 configuration register */ + __io uint32 CNDTR4; /**< Channel 4 number of data register */ + __io uint32 CPAR4; /**< Channel 4 peripheral address register */ + __io uint32 CMAR4; /**< Channel 4 memory address register */ + const uint32 RESERVED4; /**< Reserved. */ + __io uint32 CCR5; /**< Channel 5 configuration register */ + __io uint32 CNDTR5; /**< Channel 5 number of data register */ + __io uint32 CPAR5; /**< Channel 5 peripheral address register */ + __io uint32 CMAR5; /**< Channel 5 memory address register */ + const uint32 RESERVED5; /**< Reserved. */ + __io uint32 CCR6; /**< Channel 6 configuration register */ + __io uint32 CNDTR6; /**< Channel 6 number of data register */ + __io uint32 CPAR6; /**< Channel 6 peripheral address register */ + __io uint32 CMAR6; /**< Channel 6 memory address register */ + const uint32 RESERVED6; /**< Reserved. */ + __io uint32 CCR7; /**< Channel 7 configuration register */ + __io uint32 CNDTR7; /**< Channel 7 number of data register */ + __io uint32 CPAR7; /**< Channel 7 peripheral address register */ + __io uint32 CMAR7; /**< Channel 7 memory address register */ + const uint32 RESERVED7; /**< Reserved. */ +} dma_reg_map; + +/** DMA controller 1 register map base pointer */ +#define DMA1_BASE ((struct dma_reg_map*)0x40020000) + +#ifdef STM32_HIGH_DENSITY +/** DMA controller 2 register map base pointer */ +#define DMA2_BASE ((struct dma_reg_map*)0x40020400) +#endif + +/* + * Register bit definitions + */ + +/* Interrupt status register */ + +#define DMA_ISR_TEIF7_BIT 27 +#define DMA_ISR_HTIF7_BIT 26 +#define DMA_ISR_TCIF7_BIT 25 +#define DMA_ISR_GIF7_BIT 24 +#define DMA_ISR_TEIF6_BIT 23 +#define DMA_ISR_HTIF6_BIT 22 +#define DMA_ISR_TCIF6_BIT 21 +#define DMA_ISR_GIF6_BIT 20 +#define DMA_ISR_TEIF5_BIT 19 +#define DMA_ISR_HTIF5_BIT 18 +#define DMA_ISR_TCIF5_BIT 17 +#define DMA_ISR_GIF5_BIT 16 +#define DMA_ISR_TEIF4_BIT 15 +#define DMA_ISR_HTIF4_BIT 14 +#define DMA_ISR_TCIF4_BIT 13 +#define DMA_ISR_GIF4_BIT 12 +#define DMA_ISR_TEIF3_BIT 11 +#define DMA_ISR_HTIF3_BIT 10 +#define DMA_ISR_TCIF3_BIT 9 +#define DMA_ISR_GIF3_BIT 8 +#define DMA_ISR_TEIF2_BIT 7 +#define DMA_ISR_HTIF2_BIT 6 +#define DMA_ISR_TCIF2_BIT 5 +#define DMA_ISR_GIF2_BIT 4 +#define DMA_ISR_TEIF1_BIT 3 +#define DMA_ISR_HTIF1_BIT 2 +#define DMA_ISR_TCIF1_BIT 1 +#define DMA_ISR_GIF1_BIT 0 + +#define DMA_ISR_TEIF7 BIT(DMA_ISR_TEIF7_BIT) +#define DMA_ISR_HTIF7 BIT(DMA_ISR_HTIF7_BIT) +#define DMA_ISR_TCIF7 BIT(DMA_ISR_TCIF7_BIT) +#define DMA_ISR_GIF7 BIT(DMA_ISR_GIF7_BIT) +#define DMA_ISR_TEIF6 BIT(DMA_ISR_TEIF6_BIT) +#define DMA_ISR_HTIF6 BIT(DMA_ISR_HTIF6_BIT) +#define DMA_ISR_TCIF6 BIT(DMA_ISR_TCIF6_BIT) +#define DMA_ISR_GIF6 BIT(DMA_ISR_GIF6_BIT) +#define DMA_ISR_TEIF5 BIT(DMA_ISR_TEIF5_BIT) +#define DMA_ISR_HTIF5 BIT(DMA_ISR_HTIF5_BIT) +#define DMA_ISR_TCIF5 BIT(DMA_ISR_TCIF5_BIT) +#define DMA_ISR_GIF5 BIT(DMA_ISR_GIF5_BIT) +#define DMA_ISR_TEIF4 BIT(DMA_ISR_TEIF4_BIT) +#define DMA_ISR_HTIF4 BIT(DMA_ISR_HTIF4_BIT) +#define DMA_ISR_TCIF4 BIT(DMA_ISR_TCIF4_BIT) +#define DMA_ISR_GIF4 BIT(DMA_ISR_GIF4_BIT) +#define DMA_ISR_TEIF3 BIT(DMA_ISR_TEIF3_BIT) +#define DMA_ISR_HTIF3 BIT(DMA_ISR_HTIF3_BIT) +#define DMA_ISR_TCIF3 BIT(DMA_ISR_TCIF3_BIT) +#define DMA_ISR_GIF3 BIT(DMA_ISR_GIF3_BIT) +#define DMA_ISR_TEIF2 BIT(DMA_ISR_TEIF2_BIT) +#define DMA_ISR_HTIF2 BIT(DMA_ISR_HTIF2_BIT) +#define DMA_ISR_TCIF2 BIT(DMA_ISR_TCIF2_BIT) +#define DMA_ISR_GIF2 BIT(DMA_ISR_GIF2_BIT) +#define DMA_ISR_TEIF1 BIT(DMA_ISR_TEIF1_BIT) +#define DMA_ISR_HTIF1 BIT(DMA_ISR_HTIF1_BIT) +#define DMA_ISR_TCIF1 BIT(DMA_ISR_TCIF1_BIT) +#define DMA_ISR_GIF1 BIT(DMA_ISR_GIF1_BIT) + +/* Interrupt flag clear register */ + +#define DMA_IFCR_CTEIF7_BIT 27 +#define DMA_IFCR_CHTIF7_BIT 26 +#define DMA_IFCR_CTCIF7_BIT 25 +#define DMA_IFCR_CGIF7_BIT 24 +#define DMA_IFCR_CTEIF6_BIT 23 +#define DMA_IFCR_CHTIF6_BIT 22 +#define DMA_IFCR_CTCIF6_BIT 21 +#define DMA_IFCR_CGIF6_BIT 20 +#define DMA_IFCR_CTEIF5_BIT 19 +#define DMA_IFCR_CHTIF5_BIT 18 +#define DMA_IFCR_CTCIF5_BIT 17 +#define DMA_IFCR_CGIF5_BIT 16 +#define DMA_IFCR_CTEIF4_BIT 15 +#define DMA_IFCR_CHTIF4_BIT 14 +#define DMA_IFCR_CTCIF4_BIT 13 +#define DMA_IFCR_CGIF4_BIT 12 +#define DMA_IFCR_CTEIF3_BIT 11 +#define DMA_IFCR_CHTIF3_BIT 10 +#define DMA_IFCR_CTCIF3_BIT 9 +#define DMA_IFCR_CGIF3_BIT 8 +#define DMA_IFCR_CTEIF2_BIT 7 +#define DMA_IFCR_CHTIF2_BIT 6 +#define DMA_IFCR_CTCIF2_BIT 5 +#define DMA_IFCR_CGIF2_BIT 4 +#define DMA_IFCR_CTEIF1_BIT 3 +#define DMA_IFCR_CHTIF1_BIT 2 +#define DMA_IFCR_CTCIF1_BIT 1 +#define DMA_IFCR_CGIF1_BIT 0 + +#define DMA_IFCR_CTEIF7 BIT(DMA_IFCR_CTEIF7_BIT) +#define DMA_IFCR_CHTIF7 BIT(DMA_IFCR_CHTIF7_BIT) +#define DMA_IFCR_CTCIF7 BIT(DMA_IFCR_CTCIF7_BIT) +#define DMA_IFCR_CGIF7 BIT(DMA_IFCR_CGIF7_BIT) +#define DMA_IFCR_CTEIF6 BIT(DMA_IFCR_CTEIF6_BIT) +#define DMA_IFCR_CHTIF6 BIT(DMA_IFCR_CHTIF6_BIT) +#define DMA_IFCR_CTCIF6 BIT(DMA_IFCR_CTCIF6_BIT) +#define DMA_IFCR_CGIF6 BIT(DMA_IFCR_CGIF6_BIT) +#define DMA_IFCR_CTEIF5 BIT(DMA_IFCR_CTEIF5_BIT) +#define DMA_IFCR_CHTIF5 BIT(DMA_IFCR_CHTIF5_BIT) +#define DMA_IFCR_CTCIF5 BIT(DMA_IFCR_CTCIF5_BIT) +#define DMA_IFCR_CGIF5 BIT(DMA_IFCR_CGIF5_BIT) +#define DMA_IFCR_CTEIF4 BIT(DMA_IFCR_CTEIF4_BIT) +#define DMA_IFCR_CHTIF4 BIT(DMA_IFCR_CHTIF4_BIT) +#define DMA_IFCR_CTCIF4 BIT(DMA_IFCR_CTCIF4_BIT) +#define DMA_IFCR_CGIF4 BIT(DMA_IFCR_CGIF4_BIT) +#define DMA_IFCR_CTEIF3 BIT(DMA_IFCR_CTEIF3_BIT) +#define DMA_IFCR_CHTIF3 BIT(DMA_IFCR_CHTIF3_BIT) +#define DMA_IFCR_CTCIF3 BIT(DMA_IFCR_CTCIF3_BIT) +#define DMA_IFCR_CGIF3 BIT(DMA_IFCR_CGIF3_BIT) +#define DMA_IFCR_CTEIF2 BIT(DMA_IFCR_CTEIF2_BIT) +#define DMA_IFCR_CHTIF2 BIT(DMA_IFCR_CHTIF2_BIT) +#define DMA_IFCR_CTCIF2 BIT(DMA_IFCR_CTCIF2_BIT) +#define DMA_IFCR_CGIF2 BIT(DMA_IFCR_CGIF2_BIT) +#define DMA_IFCR_CTEIF1 BIT(DMA_IFCR_CTEIF1_BIT) +#define DMA_IFCR_CHTIF1 BIT(DMA_IFCR_CHTIF1_BIT) +#define DMA_IFCR_CTCIF1 BIT(DMA_IFCR_CTCIF1_BIT) +#define DMA_IFCR_CGIF1 BIT(DMA_IFCR_CGIF1_BIT) + +/* Channel configuration register */ + +#define DMA_CCR_MEM2MEM_BIT 14 +#define DMA_CCR_MINC_BIT 7 +#define DMA_CCR_PINC_BIT 6 +#define DMA_CCR_CIRC_BIT 5 +#define DMA_CCR_DIR_BIT 4 +#define DMA_CCR_TEIE_BIT 3 +#define DMA_CCR_HTIE_BIT 2 +#define DMA_CCR_TCIE_BIT 1 +#define DMA_CCR_EN_BIT 0 + +#define DMA_CCR_MEM2MEM BIT(DMA_CCR_MEM2MEM_BIT) +#define DMA_CCR_PL (0x3 << 12) +#define DMA_CCR_PL_LOW (0x0 << 12) +#define DMA_CCR_PL_MEDIUM (0x1 << 12) +#define DMA_CCR_PL_HIGH (0x2 << 12) +#define DMA_CCR_PL_VERY_HIGH (0x3 << 12) +#define DMA_CCR_MSIZE (0x3 << 10) +#define DMA_CCR_MSIZE_8BITS (0x0 << 10) +#define DMA_CCR_MSIZE_16BITS (0x1 << 10) +#define DMA_CCR_MSIZE_32BITS (0x2 << 10) +#define DMA_CCR_PSIZE (0x3 << 8) +#define DMA_CCR_PSIZE_8BITS (0x0 << 8) +#define DMA_CCR_PSIZE_16BITS (0x1 << 8) +#define DMA_CCR_PSIZE_32BITS (0x2 << 8) +#define DMA_CCR_MINC BIT(DMA_CCR_MINC_BIT) +#define DMA_CCR_PINC BIT(DMA_CCR_PINC_BIT) +#define DMA_CCR_CIRC BIT(DMA_CCR_CIRC_BIT) +#define DMA_CCR_DIR BIT(DMA_CCR_DIR_BIT) +#define DMA_CCR_TEIE BIT(DMA_CCR_TEIE_BIT) +#define DMA_CCR_HTIE BIT(DMA_CCR_HTIE_BIT) +#define DMA_CCR_TCIE BIT(DMA_CCR_TCIE_BIT) +#define DMA_CCR_EN BIT(DMA_CCR_EN_BIT) + +/* + * Devices + */ + +/** Encapsulates state related to a DMA channel interrupt. */ +typedef struct dma_handler_config { + void (*handler)(void); + nvic_irq_num irq_line; +} dma_handler_config; + +/** DMA device type */ +typedef struct dma_dev { + dma_reg_map *regs; /**< Register map */ + rcc_clk_id clk_id; /**< Clock ID */ + dma_handler_config handlers[]; /**< IRQ handlers and NVIC numbers. */ +} dma_dev; + +/** DMA1 device */ +extern dma_dev *DMA1; +#ifdef STM32_HIGH_DENSITY +/** DMA2 device */ +extern dma_dev *DMA2; +#endif + +/* + * Convenience functions + */ + +void dma_init(dma_dev *dev); /** Flags for DMA transfer configuration. */ typedef enum dma_mode_flags { - DMA_MINC_MODE = 1 << 7, /**< Auto-increment memory address */ - DMA_PINC_MODE = 1 << 6, /**< Auto-increment peripheral address */ - DMA_CIRC_MODE = 1 << 5, /**< Circular mode */ - DMA_FROM_MEM = 1 << 4, /**< Read from memory to peripheral */ - DMA_TRNS_ERR = 1 << 3, /**< Interrupt on transfer error */ - DMA_HALF_TRNS = 1 << 2, /**< Interrupt on half-transfer */ - DMA_TRNS_CMPLT = 1 << 1 /**< Interrupt on transfer completion */ + DMA_MEM_2_MEM = 1 << 14, /**< Memory to memory mode */ + DMA_MINC_MODE = 1 << 7, /**< Auto-increment memory address */ + DMA_PINC_MODE = 1 << 6, /**< Auto-increment peripheral address */ + DMA_CIRC_MODE = 1 << 5, /**< Circular mode */ + DMA_FROM_MEM = 1 << 4, /**< Read from memory to peripheral */ + DMA_TRNS_ERR = 1 << 3, /**< Interrupt on transfer error */ + DMA_HALF_TRNS = 1 << 2, /**< Interrupt on half-transfer */ + DMA_TRNS_CMPLT = 1 << 1 /**< Interrupt on transfer completion */ } dma_mode_flags; /** Source and destination transfer sizes. */ -typedef enum dma_transfer_size { - DMA_SIZE_8BITS = 0, - DMA_SIZE_16BITS = 1, - DMA_SIZE_32BITS = 2 -} dma_transfer_size; +typedef enum dma_xfer_size { + DMA_SIZE_8BITS = 0, /**< 8-bit transfers */ + DMA_SIZE_16BITS = 1, /**< 16-bit transfers */ + DMA_SIZE_32BITS = 2 /**< 32-bit transfers */ +} dma_xfer_size; + +/** DMA channel */ +typedef enum dma_channel { + DMA_CH1 = 1, /**< Channel 1 */ + DMA_CH2 = 2, /**< Channel 2 */ + DMA_CH3 = 3, /**< Channel 3 */ + DMA_CH4 = 4, /**< Channel 4 */ + DMA_CH5 = 5, /**< Channel 5 */ + DMA_CH6 = 6, /**< Channel 6 */ + DMA_CH7 = 7, /**< Channel 7 */ +} dma_channel; + +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); + +void dma_set_num_transfers(dma_dev *dev, + dma_channel channel, + uint16 num_transfers); + +/** DMA transfer priority. */ +typedef enum dma_priority { + DMA_PRIORITY_LOW = DMA_CCR_PL_LOW, /**< Low priority */ + DMA_PRIORITY_MEDIUM = DMA_CCR_PL_MEDIUM, /**< Medium priority */ + DMA_PRIORITY_HIGH = DMA_CCR_PL_HIGH, /**< High priority */ + DMA_PRIORITY_VERY_HIGH = DMA_CCR_PL_VERY_HIGH /**< Very high priority */ +} dma_priority; + +void dma_set_priority(dma_dev *dev, + dma_channel channel, + dma_priority priority); + +void dma_attach_interrupt(dma_dev *dev, + dma_channel channel, + void (*handler)(void)); +void dma_detach_interrupt(dma_dev *dev, dma_channel channel); + +/** + * Encodes the reason why a DMA interrupt was called. + * @see dma_get_irq_cause() + */ +typedef enum dma_irq_cause { + DMA_TRANSFER_COMPLETE, /**< Transfer is complete. */ + DMA_TRANSFER_HALF_COMPLETE, /**< Transfer is half complete. */ + DMA_TRANSFER_ERROR, /**< Error occurred during transfer. */ +} dma_irq_cause; + +dma_irq_cause dma_get_irq_cause(dma_dev *dev, dma_channel channel); + +void dma_enable(dma_dev *dev, dma_channel channel); +void dma_disable(dma_dev *dev, dma_channel channel); + +void dma_set_mem_addr(dma_dev *dev, dma_channel channel, __io void *address); +void dma_set_per_addr(dma_dev *dev, dma_channel channel, __io void *address); /** - * Initialize a DMA channel. If desired, attach an interrupt handler - * using dma_attach_interrupt(). Start the transfer using - * dma_start(). + * @brief DMA channel register map type. * - * @param channel the channel number (1..7) - * @param paddr address of the peripheral - * @param psize peripheral size - * @param msize memory size - * @param mode OR of the dma_mode_flags - * @see dma_mode_flags - * @see dma_attach_interrupt() - * @see dma_start() */ -void dma_init(uint8 channel, volatile void *paddr, - dma_transfer_size psize, dma_transfer_size msize, - int mode); + * Provides access to an individual channel's registers. + */ +typedef struct dma_channel_reg_map { + __io uint32 CCR; /**< Channel configuration register */ + __io uint32 CNDTR; /**< Channel number of data register */ + __io uint32 CPAR; /**< Channel peripheral address register */ + __io uint32 CMAR; /**< Channel memory address register */ +} dma_channel_reg_map; + +#define DMA_CHANNEL_NREGS 5 /** - * Begin a DMA transfer initialized with dma_init(). + * @brief Obtain a pointer to an individual DMA channel's registers. * - * @param channel Channel transfer to start. - * @param buffer Buffer to write to (unless DMA_FROM_MEM was set in - * mode argument to dma_init(), in which case, buffer - * to read from). This must be aligned with msize - * argument to dma_init(). - * @param count Number of elements to transfer. - * @see dma_init() */ -void dma_start(uint8 channel, volatile void *buffer, uint16 count); + * For example, dma_channel_regs(DMA1, DMA_CH1)->CCR is DMA1_BASE->CCR1. + * + * @param dev DMA device + * @param channel DMA channel whose channel register map to obtain. + */ +static inline dma_channel_reg_map* dma_channel_regs(dma_dev *dev, + dma_channel channel) { + __io uint32 *ccr1 = &dev->regs->CCR1; + return (dma_channel_reg_map*)(ccr1 + DMA_CHANNEL_NREGS * (channel - 1)); +} + +/** + * @brief Check if a DMA channel is enabled + * @param dev DMA device + * @param channel Channel whose enabled bit to check. + */ +static inline uint8 dma_is_channel_enabled(dma_dev *dev, dma_channel channel) { + return (uint8)(dma_channel_regs(dev, channel)->CCR & DMA_CCR_EN); +} /** - * Attach an interrupt handler for the given DMA channel. - * @param channel DMA channel (1..7) - * @param handler Interrupt handler to attach - * @see voidFuncPtr */ -void dma_attach_interrupt(uint8 channel, voidFuncPtr handler); + * @brief Get the ISR status bits for a DMA channel. + * + * The bits are returned right-aligned, in the following order: + * transfer error flag, half-transfer flag, transfer complete flag, + * global interrupt flag. + * + * If you're attempting to figure out why a DMA interrupt fired; you + * may find dma_get_irq_cause() more convenient. + * + * @see dma_get_irq_cause(). + */ +static inline uint8 dma_get_isr_bits(dma_dev *dev, dma_channel channel) { + uint8 shift = (channel - 1) * 4; + return (dev->regs->ISR >> shift) & 0xF; +} /** - * Detach any handler associated with the given DMA channel. - * @param channel Channel whose interrupt handler to detach. */ -void dma_detach_interrupt(uint8 channel); + * @brief Clear the ISR status bits for a given DMA channel. + * + * If you're attempting to clean up after yourself in a DMA interrupt, + * you may find dma_get_irq_cause() more convenient. + * + * @see dma_get_irq_cause() + */ +static inline void dma_clear_isr_bits(dma_dev *dev, dma_channel channel) { + dev->regs->IFCR = BIT(4 * (channel - 1)); +} #ifdef __cplusplus } // extern "C" diff --git a/libmaple/nvic.h b/libmaple/nvic.h index df3461b..2e98c9f 100644 --- a/libmaple/nvic.h +++ b/libmaple/nvic.h @@ -31,6 +31,7 @@ #define _NVIC_H_ #include "libmaple_types.h" +#include "util.h" #ifdef __cplusplus extern "C"{ diff --git a/notes/dma.txt b/notes/dma.txt new file mode 100644 index 0000000..97b23a0 --- /dev/null +++ b/notes/dma.txt @@ -0,0 +1,99 @@ +DMA Notes +========= + +Medium-density devices have one DMA controller, DMA1. High-density +devices and up also have DMA2. DMA1 has 7 channels; DMA2 has 5. Each +channel multiplexes DMA requests from various peripherals, like so: + +Channel Capabilities +-------------------- + +DMA1: + + * Channel 1: ADC1, TIM2_CH3, TIM4_CH1 + * Channel 2: USART3_TX, TIM1_CH1, TIM2_UP, TIM3_CH3, SPI1_RX + * Channel 3: USART3_RX, TIM1_CH2, TIM3_CH4, TIM3_UP, SPI1_TX + * Channel 4: USART1_TX, TIM1_CH4, TIM1_TRIG, TIM1_COM, TIM4_CH2, + SPI2/I2S2_RX, I2C2_TX + * Channel 5: USART1_RX, TIM1_UP, TIM2_CH1, TIM4_CH3, + SPI2/I2S2_TX, I2C2_RX + * Channel 6: USART2_RX, TIM1_CH3, TIM3_CH1, TIM3_TRIG, I2C1_TX + * Channel 7: USART2_TX, TIM2_CH2, TIM2_CH4, TIM4_UP, I2C1_RX + +DMA2: + + * Channel 1: TIM5_CH4, TIM5_TRIG, TIM8_CH3, TIM8_UP, SPI/I2S3_RX + * Channel 2: TIM8_CH4, TIM8_TRIG, TIM8_COM, TIM5_CH3, TIM5_UP, SPI/I2S3_TX + * Channel 3: TIM8_CH1, UART4_RX, TIM6_UP/DAC_CH1 + * Channel 4: TIM5_CH2, SDIO, TIM7_UP/DAC_CH2 + * Channel 5: ADC3, TIM8_CH2, TIM5_CH1, UART4_TX + +An example usage: via DMA1, channel 1, you can have ADC1 periodically +dump converted data into an array in memory. The DMA controller can +then interrupt you when the array is half-full and full, and if any +error occurred. + +Since channels are multiplexed in hardware, you can't simultaneously +use the same DMA channel to serve requests from two of its peripherals +at the same time. For example, if you are using DMA 1 channel 1 to +serve DMA requests from ADC1, you can't also serve requests from Timer +2 channel 3. + +Channel Priority +---------------- + +An arbiter prioritizes simultaneous channel DMA requests. Channel +priority levels are configurable (4 levels of priority). Ties within +a DMA controller are broken by choosing the lower channel number; +between the controllers, DMA1 has higher priority than DMA2. + +Interrupts +---------- + +You can cause an interrupt to fire once half the transfers are +complete, when all the transfers are complete, if an error occurs +during transfer, or any combination of the three. + +If an error occurs, the transfer is automatically disabled. + +Configuration +------------- + +In order to configure a DMA transfer for DMA controller n, channel x, +ST RM0008 says you should do the following: + + A. Set the peripheral register address in DMAn_BASE->CPARx. + B. Set the memory address in DMAn_BASE->CMARx. + C. Set the number of data to be transferred in DMAn_BASE->CNDTRx. + D. Set the channel priority via the PL bits in DMAn_BASE->CCRx. + E. Configure various other things (e.g. data transfer sizes, what + events cause channel interrupts) in DMAn_BASE->CCRx as desired. + F. Activate the channel by setting ENABLE bit in DMAn_BASE->CCRx. + +The channel will start serving DMA requests as soon as it's activated. + +The DMA library lets you accomplish these tasks as follows: + + **Setup transfer** + + Do (A), (B), and (E) using dma_setup_transfer(). + + This also does (D), but chooses the lowest priority by default. + + **Perform any other desired configuration** + + You can do (C) using dma_set_num_transfers(). + + You can do (D) using dma_set_priority(). + + You can attach interrupt handlers with dma_attach_interrupt(). + + **Activate the channel** + + Do (F) with dma_enable(). + +Once you're all done, you can dma_disable() the channel. If you +dma_detach_interrupt() an interrupt handler, the channel interrupts +will stop firing, but the transfer itself won't stop until it's done +(which never happens if you set the DMA_CIRC_MODE flag when you called +dma_setup_transfer()). |