From 9c603069e41bfe56b9a7f37e1e939db2f25bf710 Mon Sep 17 00:00:00 2001 From: Rob Austein Date: Wed, 23 May 2018 01:40:05 -0400 Subject: Simplify FMC I/O code. We're no longer using a preemptive multitasker, and we're on the Alpha, not the old bridge board, so all we really need to do is read or write one word at a time via a pointer then wait for the GPIO idle pin to light. Well, other than needing to read twice because of a known hardware problem with the STM32. So we dont need to fiddle with IRQ, or use the CMSIS SRAM lock, or.... --- stm-fmc.c | 51 ++++++++++++++------------------------------------- 1 file changed, 14 insertions(+), 37 deletions(-) diff --git a/stm-fmc.c b/stm-fmc.c index 1302564..1987ebe 100644 --- a/stm-fmc.c +++ b/stm-fmc.c @@ -184,38 +184,19 @@ static HAL_StatusTypeDef _fmc_nwait_idle(void) HAL_StatusTypeDef fmc_write_32(uint32_t addr, uint32_t *data) { // calculate target fpga address - uint32_t ptr = FMC_FPGA_BASE_ADDR + (addr & FMC_FPGA_ADDR_MASK); + uint32_t *ptr = (uint32_t *) (FMC_FPGA_BASE_ADDR + (addr & FMC_FPGA_ADDR_MASK)); - __disable_irq(); + // write data to fpga + *ptr = *data; - HAL_StatusTypeDef status = - // write data to fpga - HAL_SRAM_Write_32b(&_fmc_fpga_inst, (uint32_t *)ptr, data, 1); - if (status == HAL_OK) - // wait for transaction to complete - status = _fmc_nwait_idle(); - - __enable_irq(); - - return status; -} - -static inline HAL_StatusTypeDef _fmc_read_32(uint32_t *ptr, uint32_t *data) -{ - HAL_StatusTypeDef status = - // read data from fpga - HAL_SRAM_Read_32b(&_fmc_fpga_inst, (uint32_t *)ptr, data, 1); - if (status == HAL_OK) - // wait for transaction to complete - status = _fmc_nwait_idle(); - - return status; + // wait for transaction to complete + return _fmc_nwait_idle(); } HAL_StatusTypeDef fmc_read_32(uint32_t addr, uint32_t *data) { // calculate target fpga address - uint32_t ptr = FMC_FPGA_BASE_ADDR + (addr & FMC_FPGA_ADDR_MASK); + 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 @@ -227,20 +208,16 @@ HAL_StatusTypeDef fmc_read_32(uint32_t addr, uint32_t *data) * two times. */ - /* Add some level of reentrancy protection. When running under a - * preemptive multitasker, with two threads banging on the fpga, we appear - * to sometimes read the wrong value. I think this is because the second - * read counts on the first read to put the correct value on the address - * bus. - */ - __disable_irq(); + HAL_StatusTypeDef status; + + *data = *ptr; + status = _fmc_nwait_idle(); - HAL_StatusTypeDef status = - _fmc_read_32((uint32_t *)ptr, data); - if (status == HAL_OK) - status = _fmc_read_32((uint32_t *)ptr, data); + if (status != HAL_OK) + return status; - __enable_irq(); + *data = *ptr; + status = _fmc_nwait_idle(); return status; } -- cgit v1.2.3