From da50827657d6bc3024dd6acea76cb315d1cbbae1 Mon Sep 17 00:00:00 2001 From: yn386 Date: Wed, 31 Aug 2022 19:13:00 +0900 Subject: [PATCH] stm32/pyb_i2c: Fix pyb.I2C to work with dma=True on F4 MCUs. Prior to this commit, excuting this code: i2c = I2C(1, I2C.CONTROLLER, dma=True) i2c.send(data, addr=i2c_addr) the call to i2c.send() does not return and the board needs a reset. This code works when dma=False. According to the specification, I2Cx_EV_IRQHandler should: - Write DR to address when Start condition generated. - Clear ADDR by reading SR2 after reading SR2 when address sent. These processes are included in HAL_I2C_EV_IRQHandler(), however the firmware size increses about 2KB if HAL_I2C_EV_IRQHandler is called. This commit adds above processes to i2c_ev_irq_handler, and increases firmware by less than 100 bytes. Fixes issue #2643. --- ports/stm32/pyb_i2c.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/ports/stm32/pyb_i2c.c b/ports/stm32/pyb_i2c.c index 436b1c9bc2..e9877422ca 100644 --- a/ports/stm32/pyb_i2c.c +++ b/ports/stm32/pyb_i2c.c @@ -472,7 +472,17 @@ void i2c_ev_irq_handler(mp_uint_t i2c_id) { #if defined(STM32F4) - if (hi2c->Instance->SR1 & I2C_FLAG_BTF && hi2c->State == HAL_I2C_STATE_BUSY_TX) { + if (hi2c->Instance->SR1 & I2C_FLAG_SB) { + if (hi2c->State == HAL_I2C_STATE_BUSY_TX) { + hi2c->Instance->DR = I2C_7BIT_ADD_WRITE(hi2c->Devaddress); + } else { + hi2c->Instance->DR = I2C_7BIT_ADD_READ(hi2c->Devaddress); + } + } else if (hi2c->Instance->SR1 & I2C_FLAG_ADDR) { + __IO uint32_t tmp_sr2; + tmp_sr2 = hi2c->Instance->SR2; + UNUSED(tmp_sr2); + } else if (hi2c->Instance->SR1 & I2C_FLAG_BTF && hi2c->State == HAL_I2C_STATE_BUSY_TX) { if (hi2c->XferCount != 0U) { hi2c->Instance->DR = *hi2c->pBuffPtr++; hi2c->XferCount--;