diff options
| author | Wei-Han Chen <stimim@google.com> | 2018-01-08 16:51:26 +0800 |
|---|---|---|
| committer | chrome-bot <chrome-bot@chromium.org> | 2018-01-25 00:15:48 -0800 |
| commit | 9a7e82bac8f8fbfa10e0e2a1f1ea33fb1d6b75cc (patch) | |
| tree | 0834587dfa4a95ed38fed2974b470beaa862ca5b /chip/stm32/dma.c | |
| parent | e68469b5242b9b95ea5de45c965825da35b7eaab (diff) | |
| download | chrome-ec-9a7e82bac8f8fbfa10e0e2a1f1ea33fb1d6b75cc.tar.gz | |
stm32: make half-duplex SPI works on STM32F0
According to RM0091, steps for using DMA for SPI peripheral should be:
1. enable DMA RX / TX
2. enable SPI
3. wait for DMA to complete
4. disable DMA RX / TX
5. disable SPI
BUG=b:70482333
TEST=tested on reworked staff (half-duplex)
TEST=tested elm (full-duplex)
Change-Id: I095409195cd1e0379995f0bfa6605c2e1a0dfd3c
Reviewed-on: https://chromium-review.googlesource.com/853715
Commit-Ready: Wei-Han Chen <stimim@chromium.org>
Tested-by: Wei-Han Chen <stimim@chromium.org>
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>
Diffstat (limited to 'chip/stm32/dma.c')
| -rw-r--r-- | chip/stm32/dma.c | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/chip/stm32/dma.c b/chip/stm32/dma.c index 9c08973098..26dfa0f823 100644 --- a/chip/stm32/dma.c +++ b/chip/stm32/dma.c @@ -104,13 +104,14 @@ void dma_disable_all(void) * STM32_DMA_CCR_MINC | STM32_DMA_CCR_DIR for tx * 0 for rx */ -static void prepare_channel(stm32_dma_chan_t *chan, unsigned count, +static void prepare_channel(enum dma_channel channel, unsigned count, void *periph, void *memory, unsigned flags) { + stm32_dma_chan_t *chan = dma_get_channel(channel); uint32_t ccr = STM32_DMA_CCR_PL_VERY_HIGH; - if (chan->ccr & STM32_DMA_CCR_EN) - chan->ccr &= ~STM32_DMA_CCR_EN; + dma_disable(channel); + dma_clear_isr(channel); /* Following the order in Doc ID 15965 Rev 5 p194 */ chan->cpar = (uint32_t)periph; @@ -133,13 +134,11 @@ void dma_go(stm32_dma_chan_t *chan) void dma_prepare_tx(const struct dma_option *option, unsigned count, const void *memory) { - stm32_dma_chan_t *chan = dma_get_channel(option->channel); - /* * Cast away const for memory pointer; this is ok because we know * we're preparing the channel for transmit. */ - prepare_channel(chan, count, option->periph, (void *)memory, + prepare_channel(option->channel, count, option->periph, (void *)memory, STM32_DMA_CCR_MINC | STM32_DMA_CCR_DIR | option->flags); } @@ -148,8 +147,7 @@ void dma_start_rx(const struct dma_option *option, unsigned count, void *memory) { stm32_dma_chan_t *chan = dma_get_channel(option->channel); - - prepare_channel(chan, count, option->periph, memory, + prepare_channel(option->channel, count, option->periph, memory, STM32_DMA_CCR_MINC | option->flags); dma_go(chan); } |