diff options
| author | Clément Le Goffic <clement.legoffic@foss.st.com> | 2025-07-04 10:39:16 +0200 |
|---|---|---|
| committer | Andi Shyti <andi.shyti@kernel.org> | 2025-07-30 00:30:43 +0200 |
| commit | ffdd20555cc6fcb15e8a57d442c458034d169c7b (patch) | |
| tree | c04761c6e8f70792608043dfc930bace83d380d6 | |
| parent | 0ae982df67760cd08affa935c0fe86c8a9311797 (diff) | |
i2c: stm32f7: support i2c_*_dma_safe_msg_buf APIs
`i2c_*_dma_safe_msg_buf` APIs operate on a `struct i2c_msg`.
The get operation make sure the I2C buffer is DMA'able according to its
buffer length, or if the memory use is DMA coherent for example and
return a valid pointer for safe DMA access to be used.
The put operation release the pointer.
Prefer using generic API's than relying on private tests.
Acked-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20250704-i2c-upstream-v4-3-84a095a2c728@foss.st.com
| -rw-r--r-- | drivers/i2c/busses/i2c-stm32f7.c | 32 |
1 files changed, 21 insertions, 11 deletions
diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c index c8b4b404f6c1..e6815f6cae78 100644 --- a/drivers/i2c/busses/i2c-stm32f7.c +++ b/drivers/i2c/busses/i2c-stm32f7.c @@ -742,11 +742,14 @@ static void stm32f7_i2c_dma_callback(void *arg) { struct stm32f7_i2c_dev *i2c_dev = arg; struct stm32_i2c_dma *dma = i2c_dev->dma; + struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; stm32f7_i2c_disable_dma_req(i2c_dev); dmaengine_terminate_async(dma->chan_using); dma_unmap_single(i2c_dev->dev, dma->dma_buf, dma->dma_len, dma->dma_data_dir); + if (!f7_msg->smbus) + i2c_put_dma_safe_msg_buf(f7_msg->buf, i2c_dev->msg, true); complete(&dma->dma_complete); } @@ -882,6 +885,7 @@ static void stm32f7_i2c_xfer_msg(struct stm32f7_i2c_dev *i2c_dev, { struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; void __iomem *base = i2c_dev->base; + u8 *dma_buf; u32 cr1, cr2; int ret; @@ -931,17 +935,23 @@ static void stm32f7_i2c_xfer_msg(struct stm32f7_i2c_dev *i2c_dev, /* Configure DMA or enable RX/TX interrupt */ i2c_dev->use_dma = false; - if (i2c_dev->dma && f7_msg->count >= STM32F7_I2C_DMA_LEN_MIN - && !i2c_dev->atomic) { - ret = stm32_i2c_prep_dma_xfer(i2c_dev->dev, i2c_dev->dma, - msg->flags & I2C_M_RD, - f7_msg->count, f7_msg->buf, - stm32f7_i2c_dma_callback, - i2c_dev); - if (!ret) - i2c_dev->use_dma = true; - else - dev_warn(i2c_dev->dev, "can't use DMA\n"); + if (i2c_dev->dma && !i2c_dev->atomic) { + dma_buf = i2c_get_dma_safe_msg_buf(msg, STM32F7_I2C_DMA_LEN_MIN); + if (dma_buf) { + f7_msg->buf = dma_buf; + ret = stm32_i2c_prep_dma_xfer(i2c_dev->dev, i2c_dev->dma, + msg->flags & I2C_M_RD, + f7_msg->count, f7_msg->buf, + stm32f7_i2c_dma_callback, + i2c_dev); + if (ret) { + dev_warn(i2c_dev->dev, "can't use DMA\n"); + i2c_put_dma_safe_msg_buf(f7_msg->buf, msg, false); + f7_msg->buf = msg->buf; + } else { + i2c_dev->use_dma = true; + } + } } if (!i2c_dev->use_dma) { |