diff options
author | Rob Austein <sra@hactrn.net> | 2018-05-27 02:28:32 -0400 |
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committer | Rob Austein <sra@hactrn.net> | 2018-05-27 02:28:32 -0400 |
commit | 64126d628fe4b6e49bcd143f199710c40115817a (patch) | |
tree | 442d2fa04111c8ab9a5be184472136bc5b299688 /stm-fmc.h | |
parent | 9c603069e41bfe56b9a7f37e1e939db2f25bf710 (diff) |
Convert FMC I/O functions to static inline.
fmc_read_32() and fmc_write_32() get called often enough that it's
worth eliminating unnecessary function call overhead.
Diffstat (limited to 'stm-fmc.h')
-rw-r--r-- | stm-fmc.h | 58 |
1 files changed, 56 insertions, 2 deletions
@@ -57,7 +57,61 @@ extern void fmc_init(void); -extern HAL_StatusTypeDef fmc_write_32(uint32_t addr, uint32_t *data); -extern HAL_StatusTypeDef fmc_read_32(uint32_t addr, uint32_t *data); + +static inline HAL_StatusTypeDef _fmc_nwait_idle(void) +{ + int cnt; + + // poll NWAIT (number of iterations is limited) + for (cnt=0; cnt<FMC_FPGA_NWAIT_MAX_POLL_TICKS; cnt++) + { + // read pin state + if (HAL_GPIO_ReadPin(FMC_GPIO_PORT_NWAIT, FMC_GPIO_PIN_NWAIT) == FMC_NWAIT_IDLE) + return HAL_OK; + } + + return HAL_ERROR; +} + +static inline HAL_StatusTypeDef fmc_write_32(uint32_t addr, uint32_t *data) +{ + // calculate target fpga address + uint32_t *ptr = (uint32_t *) (FMC_FPGA_BASE_ADDR + (addr & FMC_FPGA_ADDR_MASK)); + + // write data to fpga + *ptr = *data; + + // wait for transaction to complete + return _fmc_nwait_idle(); +} + +static inline HAL_StatusTypeDef fmc_read_32(uint32_t addr, uint32_t *data) +{ + // calculate target fpga address + uint32_t *ptr = (uint32_t *) (FMC_FPGA_BASE_ADDR + (addr & FMC_FPGA_ADDR_MASK)); + + /* Pavel says: + * The short story is like, on one hand STM32 has a dedicated FMC_NWAIT + * pin, that can be used in variable-latency data transfer mode. On the + * other hand STM32 also has a very nasty hardware bug associated with + * FMC_WAIT, that causes processor to freeze under certain conditions. + * Because of this FMC_NWAIT cannot be used and FPGA can't properly signal + * to STM32, when data transfer is done. Because of that we have to read + * two times. + */ + + HAL_StatusTypeDef status; + + *data = *ptr; + status = _fmc_nwait_idle(); + + if (status != HAL_OK) + return status; + + *data = *ptr; + status = _fmc_nwait_idle(); + + return status; +} #endif /* __STM_FMC_H */ |