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Diffstat (limited to 'libmaple/stm32f2/dma.c')
| -rw-r--r-- | libmaple/stm32f2/dma.c | 504 |
1 files changed, 504 insertions, 0 deletions
diff --git a/libmaple/stm32f2/dma.c b/libmaple/stm32f2/dma.c new file mode 100644 index 0000000..26e87b9 --- /dev/null +++ b/libmaple/stm32f2/dma.c @@ -0,0 +1,504 @@ +/****************************************************************************** + * The MIT License + * + * 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/stm32f2/dma.c + * @author Marti Bolivar <mbolivar@leaflabs.com> + * @brief STM32F2 DMA support. + */ + +#include <libmaple/dma.h> +#include <libmaple/bitband.h> +#include <libmaple/util.h> + +/* Hack to ensure inlining in dma_irq_handler() */ +#define DMA_GET_HANDLER(dev, tube) (dev->handlers[tube].handler) +#include "dma_private.h" + +/* + * Devices + */ + +static dma_dev dma1 = { + .regs = DMA1_BASE, + .clk_id = RCC_DMA1, + .handlers = {{ .handler = NULL, .irq_line = NVIC_DMA1_STREAM0 }, + { .handler = NULL, .irq_line = NVIC_DMA1_STREAM1 }, + { .handler = NULL, .irq_line = NVIC_DMA1_STREAM2 }, + { .handler = NULL, .irq_line = NVIC_DMA1_STREAM3 }, + { .handler = NULL, .irq_line = NVIC_DMA1_STREAM4 }, + { .handler = NULL, .irq_line = NVIC_DMA1_STREAM5 }, + { .handler = NULL, .irq_line = NVIC_DMA1_STREAM6 }, + { .handler = NULL, .irq_line = NVIC_DMA1_STREAM7 }}, +}; +dma_dev *DMA1 = &dma1; + +static dma_dev dma2 = { + .regs = DMA2_BASE, + .clk_id = RCC_DMA2, + .handlers = {{ .handler = NULL, .irq_line = NVIC_DMA2_STREAM0 }, + { .handler = NULL, .irq_line = NVIC_DMA2_STREAM1 }, + { .handler = NULL, .irq_line = NVIC_DMA2_STREAM2 }, + { .handler = NULL, .irq_line = NVIC_DMA2_STREAM3 }, + { .handler = NULL, .irq_line = NVIC_DMA2_STREAM4 }, + { .handler = NULL, .irq_line = NVIC_DMA2_STREAM5 }, + { .handler = NULL, .irq_line = NVIC_DMA2_STREAM6 }, + { .handler = NULL, .irq_line = NVIC_DMA2_STREAM7 }}, +}; +dma_dev *DMA2 = &dma2; + +/* + * Helpers for dealing with dma_request_src's bit encoding (see the + * comments in the dma_request_src definition). + */ + +/* rcc_clk_id of dma_dev which supports src. */ +static __always_inline rcc_clk_id src_clk_id(dma_request_src src) { + return (rcc_clk_id)(((uint32)src >> 3) & 0x3F); +} + +/* Bit vector of streams supporting src (e.g., bit 0 set => DMA_S0 support). */ +static __always_inline uint32 src_stream_mask(dma_request_src src) { + return ((uint32)src >> 10) & 0xFF; +} + +/* Channel corresponding to src. */ +static __always_inline dma_channel src_channel(dma_request_src src) { + return (dma_channel)(src & 0x7); +} + +/* + * Routines + */ + +/* For convenience */ +#define ASSERT_NOT_ENABLED(dev, tube) ASSERT(!dma_is_enabled(dev, tube)) + +/* Helpers for dma_tube_cfg() */ +static int preconfig_check(dma_dev *dev, dma_tube tube, dma_tube_config *cfg); +static int postconfig_check(dma_tube_reg_map *dummy, dma_tube_config *cfg); +static int config_fifo(dma_tube_reg_map *dummy, dma_tube_config *cfg); +static int config_src_dst(dma_tube_reg_map *dummy, dma_tube_config *cfg); +static void copy_regs(dma_tube_reg_map *src, dma_tube_reg_map *dst); + +int dma_tube_cfg(dma_dev *dev, dma_tube tube, dma_tube_config *cfg) { + dma_tube_reg_map dummy_regs; + dma_tube_reg_map *tregs = dma_tube_regs(dev, tube); + int ret; + + /* Initial error checking. */ + ret = preconfig_check(dev, tube, cfg); + if (ret < 0) { + return ret; + } + + /* Disable `tube' as per RM0033. */ + dma_disable(dev, tube); + dma_clear_isr_bits(dev, tube); + + /* Don't write to tregs until we've decided `cfg' is really OK, + * so as not to make a half-formed mess if we have to error out. */ + copy_regs(tregs, &dummy_regs); + + /* Try to reconfigure `tube', bailing on error. */ + ret = config_fifo(&dummy_regs, cfg); + if (ret < 0) { + return ret; + } + ret = config_src_dst(&dummy_regs, cfg); + if (ret < 0) { + return ret; + } + dummy_regs.SNDTR = cfg->tube_nr_xfers; + ret = postconfig_check(&dummy_regs, cfg); + if (ret < 0) { + return ret; + } + + /* Ok, we're good. Commit to the new configuration. */ + copy_regs(&dummy_regs, tregs); + return ret; +} + +void dma_set_priority(dma_dev *dev, dma_stream stream, dma_priority priority) { + dma_tube_reg_map *tregs = dma_tube_regs(dev, stream); + uint32 scr; + ASSERT_NOT_ENABLED(dev, stream); + scr = tregs->SCR; + scr &= ~DMA_SCR_PL; + scr |= (priority << 16); + tregs->SCR = scr; +} + +void dma_set_num_transfers(dma_dev *dev, dma_tube tube, uint16 num_transfers) { + dma_tube_reg_map *tregs = dma_tube_regs(dev, tube); + ASSERT_NOT_ENABLED(dev, tube); + tregs->SNDTR = num_transfers; +} + +/** + * @brief Set memory 0 or memory 1 address. + * + * This is a general function for setting one of the two memory + * addresses available on the double-buffered STM32F2 DMA controllers. + * + * @param dev DMA device + * @param tube Tube on dev. + * @param n If 0, set memory 0 address. If 1, set memory 1 address. + * @param address Address to set + */ +void dma_set_mem_n_addr(dma_dev *dev, dma_tube tube, int n, + __io void *address) { + dma_tube_reg_map *tregs = dma_tube_regs(dev, tube); + uint32 addr = (uint32)address; + + ASSERT_NOT_ENABLED(dev, tube); + if (n) { + tregs->SM1AR = addr; + } else { + tregs->SM0AR = addr; + } +} + +void dma_set_per_addr(dma_dev *dev, dma_tube tube, __io void *address) { + dma_tube_reg_map *tregs = dma_tube_regs(dev, tube); + ASSERT_NOT_ENABLED(dev, tube); + tregs->SPAR = (uint32)address; +} + +/** + * @brief Enable a stream's FIFO. + * + * You may only call this function when the stream is disabled. + * + * @param dev DMA device + * @param tube Stream whose FIFO to enable. + */ +void dma_enable_fifo(dma_dev *dev, dma_tube tube) { + ASSERT_NOT_ENABLED(dev, tube); + bb_peri_set_bit(&(dma_tube_regs(dev, tube)->SFCR), DMA_SFCR_DMDIS_BIT, 1); +} + +/** + * @brief Disable a stream's FIFO. + * + * You may only call this function when the stream is disabled. + * + * @param dev DMA device + * @param tube Stream whose FIFO to disable. + */ +void dma_disable_fifo(dma_dev *dev, dma_tube tube) { + ASSERT_NOT_ENABLED(dev, tube); + bb_peri_set_bit(&(dma_tube_regs(dev, tube)->SFCR), DMA_SFCR_DMDIS_BIT, 0); +} + +void dma_attach_interrupt(dma_dev *dev, dma_tube tube, + void (*handler)(void)) { + dev->handlers[tube].handler = handler; + nvic_irq_enable(dev->handlers[tube].irq_line); +} + +void dma_detach_interrupt(dma_dev *dev, dma_tube tube) { + nvic_irq_disable(dev->handlers[tube].irq_line); + dev->handlers[tube].handler = NULL; +} + +void dma_enable(dma_dev *dev, dma_tube tube) { + dma_tube_reg_map *tregs = dma_tube_regs(dev, tube); + bb_peri_set_bit(&tregs->SCR, DMA_SCR_EN_BIT, 1); +} + +void dma_disable(dma_dev *dev, dma_tube tube) { + dma_tube_reg_map *tregs = dma_tube_regs(dev, tube); + bb_peri_set_bit(&tregs->SCR, DMA_SCR_EN_BIT, 0); + /* The stream might not get disabled immediately, so wait. */ + while (tregs->SCR & DMA_SCR_EN) + ; +} + +dma_irq_cause dma_get_irq_cause(dma_dev *dev, dma_tube tube) { + /* TODO: does it still make sense to have this function? We should + * probably just be returning the ISR bits, with some defines to + * pull the flags out. The lack of masked status bits is an + * annoyance that would require documentation to solve, though. */ + uint8 status_bits = dma_get_isr_bits(dev, tube); + dma_clear_isr_bits(dev, tube); + ASSERT(status_bits); /* Or something's very wrong */ + /* Don't change the order of these if statements. */ + if (status_bits & 0x0) { + return DMA_TRANSFER_FIFO_ERROR; + } else if (status_bits & 0x4) { + return DMA_TRANSFER_DME_ERROR; + } else if (status_bits & 0x8) { + return DMA_TRANSFER_ERROR; + } else if (status_bits & 0x20) { + return DMA_TRANSFER_COMPLETE; + } else if (status_bits & 0x10) { + return DMA_TRANSFER_HALF_COMPLETE; + } + + /* Something's wrong; one of those bits should have been set. Fail + * an assert, and mimic the error behavior in case of a high debug + * level. */ + ASSERT(0); + dma_disable(dev, tube); + return DMA_TRANSFER_ERROR; +} + +/* + * IRQ handlers + */ + +void __irq_dma1_stream0(void) { + dma_irq_handler(DMA1, DMA_S0); +} + +void __irq_dma1_stream1(void) { + dma_irq_handler(DMA1, DMA_S1); +} + +void __irq_dma1_stream2(void) { + dma_irq_handler(DMA1, DMA_S2); +} + +void __irq_dma1_stream3(void) { + dma_irq_handler(DMA1, DMA_S3); +} + +void __irq_dma1_stream4(void) { + dma_irq_handler(DMA1, DMA_S4); +} + +void __irq_dma1_stream5(void) { + dma_irq_handler(DMA1, DMA_S5); +} + +void __irq_dma1_stream6(void) { + dma_irq_handler(DMA1, DMA_S6); +} + +void __irq_dma1_stream7(void) { + dma_irq_handler(DMA1, DMA_S7); +} + +void __irq_dma2_stream0(void) { + dma_irq_handler(DMA2, DMA_S0); +} + +void __irq_dma2_stream1(void) { + dma_irq_handler(DMA2, DMA_S1); +} + +void __irq_dma2_stream2(void) { + dma_irq_handler(DMA2, DMA_S2); +} + +void __irq_dma2_stream3(void) { + dma_irq_handler(DMA2, DMA_S3); +} + +void __irq_dma2_stream4(void) { + dma_irq_handler(DMA2, DMA_S4); +} + +void __irq_dma2_stream5(void) { + dma_irq_handler(DMA2, DMA_S5); +} + +void __irq_dma2_stream6(void) { + dma_irq_handler(DMA2, DMA_S6); +} + +void __irq_dma2_stream7(void) { + dma_irq_handler(DMA2, DMA_S7); +} + +/* + * Auxiliary routines for dma_tube_cfg() + */ + +/* Is addr acceptable for use as DMA src/dst? */ +static int cfg_mem_ok(__io void *addr) { + enum dma_atype atype = _dma_addr_type(addr); + return atype == DMA_ATYPE_MEM || atype == DMA_ATYPE_PER; +} + +/* Is src -> dst a reasonable combination of [MEM,PER] -> [MEM,PER]? */ +static int cfg_dir_ok(dma_dev *dev, __io void *src, __io void *dst) { + switch (_dma_addr_type(dst)) { + case DMA_ATYPE_MEM: + /* Only DMA2 can do memory-to-memory */ + return ((_dma_addr_type(src) == DMA_ATYPE_PER) || + (dev->clk_id == RCC_DMA2)); + case DMA_ATYPE_PER: + /* Peripheral-to-peripheral is illegal */ + return _dma_addr_type(src) == DMA_ATYPE_PER; + default: /* Can't happen */ + ASSERT(0); + return 0; + } +} + +/* Initial sanity check for dma_tube_cfg() */ +static int preconfig_check(dma_dev *dev, dma_tube tube, + dma_tube_config *cfg) { + if (!(src_stream_mask(cfg->tube_req_src) & (1U << tube))) { + /* ->tube_req_src not supported by stream */ + return -DMA_TUBE_CFG_EREQ; + } + if (cfg->tube_nr_xfers > 65535) { + /* That's too many. */ + return -DMA_TUBE_CFG_ENDATA; + } + if (src_clk_id(cfg->tube_req_src) != dev->clk_id) { + /* ->tube_req_src not supported by dev */ + return -DMA_TUBE_CFG_EDEV; + } + if (!cfg_mem_ok(cfg->tube_src)) { + return -DMA_TUBE_CFG_ESRC; + } + if (!cfg_mem_ok(cfg->tube_dst)) { + return -DMA_TUBE_CFG_EDST; + } + if (!cfg_dir_ok(dev, cfg->tube_src, cfg->tube_dst)) { + return -DMA_TUBE_CFG_EDIR; + } + return DMA_TUBE_CFG_SUCCESS; +} + +static int config_fifo(dma_tube_reg_map *dummy, dma_tube_config *cfg) { + /* TODO: FIFO configuration based on cfg->target_data */ + uint32 sfcr = dummy->SFCR; + sfcr &= ~DMA_SFCR_FEIE; + sfcr |= (cfg->tube_flags & DMA_CFG_FIFO_ERR_IE) ? DMA_SFCR_FEIE : 0; + dummy->SFCR = sfcr; + return DMA_TUBE_CFG_SUCCESS; +} + +/* Helper for configuring (DMA_SxCR) */ +#define BITS_WE_CARE_ABOUT \ + (DMA_SCR_CHSEL | DMA_SCR_MBURST | DMA_SCR_PBURST | DMA_SCR_PINCOS | \ + DMA_SCR_MINC | DMA_SCR_PINC | DMA_SCR_CIRC | DMA_SCR_DIR | \ + DMA_SCR_PFCTRL | DMA_SCR_TCIE | DMA_SCR_HTIE | DMA_SCR_TEIE | \ + DMA_SCR_DMEIE) +static inline void config_scr(dma_tube_reg_map *dummy, dma_tube_config *cfg, + unsigned src_shift, uint32 src_inc, + unsigned dst_shift, uint32 dst_inc, + uint32 dir) { + /* These would go here if we supported them: MBURST, PBURST, + * PINCOS, PFCTRL. We explicitly choose low priority, and double + * buffering belongs elsewhere, I think. [mbolivar] */ + uint32 flags = cfg->tube_flags & BITS_WE_CARE_ABOUT; + uint32 scr = dummy->SCR; + scr &= ~(BITS_WE_CARE_ABOUT | DMA_SCR_PL); + scr |= (/* CHSEL */ + (src_channel(cfg->tube_req_src) << 25) | + /* MSIZE/PSIZE */ + (cfg->tube_src_size << src_shift) | + (cfg->tube_dst_size << dst_shift) | + /* MINC/PINC */ + ((cfg->tube_flags & DMA_CFG_SRC_INC) ? src_inc : 0) | + ((cfg->tube_flags & DMA_CFG_DST_INC) ? dst_inc : 0) | + /* DIR */ + dir | + /* Other flags carried by cfg->tube_flags */ + flags); + dummy->SCR = scr; +} +#undef BITS_WE_CARE_ABOUT + +/* Helper for when cfg->tube_dst is memory */ +static int config_to_mem(dma_tube_reg_map *dummy, dma_tube_config *cfg) { + uint32 dir = (_dma_addr_type(cfg->tube_src) == DMA_ATYPE_MEM ? + DMA_SCR_DIR_MEM_TO_MEM : DMA_SCR_DIR_PER_TO_MEM); + + if ((dir == DMA_SCR_DIR_MEM_TO_MEM) && (cfg->tube_flags & DMA_CFG_CIRC)) { + return -DMA_TUBE_CFG_ECFG; /* Can't do DMA_CFG_CIRC and mem->mem. */ + } + + config_scr(dummy, cfg, 11, DMA_SCR_PINC, 13, DMA_SCR_MINC, dir); + dummy->SPAR = (uint32)cfg->tube_src; + dummy->SM0AR = (uint32)cfg->tube_dst; + return DMA_TUBE_CFG_SUCCESS; +} + +/* Helper for when cfg->tube_src is peripheral */ +static int config_to_per(dma_tube_reg_map *dummy, dma_tube_config *cfg) { + config_scr(dummy, cfg, 13, DMA_SCR_MINC, 11, DMA_SCR_PINC, + DMA_SCR_DIR_MEM_TO_PER); + dummy->SM0AR = (uint32)cfg->tube_src; + dummy->SPAR = (uint32)cfg->tube_dst; + return DMA_TUBE_CFG_SUCCESS; +} + +/* Configures SCR, SPAR, SM0AR, and checks that the result is OK. */ +static int config_src_dst(dma_tube_reg_map *dummy, dma_tube_config *cfg) { + switch (_dma_addr_type(cfg->tube_dst)) { + case DMA_ATYPE_MEM: + return config_to_mem(dummy, cfg); + case DMA_ATYPE_PER: + return config_to_per(dummy, cfg); + case DMA_ATYPE_OTHER: + default: /* shut up, GCC */ + /* Can't happen */ + ASSERT(0); + return -DMA_TUBE_CFG_ECFG; + } +} + +/* Final checks we can only perform when fully configured */ +static int postconfig_check(dma_tube_reg_map *dummy, dma_tube_config *cfg) { + /* TODO add dma_get_[mem,per]_size() and use them here */ + /* msize and psize are in bytes here: */ + uint32 scr = dummy->SCR; + uint32 msize = 1U << ((scr >> 13) & 0x3); + uint32 psize = 1U << ((scr >> 11) & 0x3); + + /* Ensure NDT will work with PSIZE/MSIZE. + * + * RM0033 specifies that PSIZE, MSIZE, and NDT must be such that + * the last transfer completes; i.e. that if PSIZE < MSIZE, then + * NDT is a multiple of MSIZE/PSIZE. See e.g. Table 27. */ + if ((psize < msize) && (cfg->tube_nr_xfers % (msize / psize))) { + return -DMA_TUBE_CFG_ENDATA; + } + + /* Direct mode is only possible if MSIZE == PSIZE. */ + if ((msize != psize) && !(dummy->SFCR & DMA_SFCR_DMDIS)) { + return -DMA_TUBE_CFG_ESIZE; + } + + return DMA_TUBE_CFG_SUCCESS; +} + +/* Convenience for dealing with dummy registers */ +static void copy_regs(dma_tube_reg_map *src, dma_tube_reg_map *dst) { + dst->SCR = src->SCR; + dst->SNDTR = src->SNDTR; + dst->SPAR = src->SPAR; + dst->SM0AR = src->SM0AR; + dst->SFCR = src->SFCR; +} |