diff options
| author | Robin Gong <yibin.gong@nxp.com> | 2020-06-17 06:42:08 +0800 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2020-06-23 13:38:14 +0100 |
| commit | 809b1b04df898b6d182069146231a3cbf5f2d9cc (patch) | |
| tree | 64458c4970bab1cdccef890aa54f6267fa28c346 /include/linux/spi | |
| parent | c314360cea42e9481d9f68a73a3a776eba31ba4b (diff) | |
spi: introduce fallback to pio
Add fallback to pio mode in case dma transfer failed with error status
SPI_TRANS_FAIL_NO_START.
If spi client driver want to enable this feature please set xfer->error in
the proper place such as dmaengine_prep_slave_sg() failure detect(but no
any data put into spi bus yet). Besides, add master->fallback checking in
its can_dma() so that spi core could switch to pio next time. Please refer
to spi-imx.c.
Signed-off-by: Robin Gong <yibin.gong@nxp.com>
Link: https://lore.kernel.org/r/1592347329-28363-2-git-send-email-yibin.gong@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'include/linux/spi')
| -rw-r--r-- | include/linux/spi/spi.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index aac57b5b7c21..b4917df79637 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -447,6 +447,8 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv) * If the driver does not set this, the SPI core takes the snapshot as * close to the driver hand-over as possible. * @irq_flags: Interrupt enable state during PTP system timestamping + * @fallback: fallback to pio if dma transfer return failure with + * SPI_TRANS_FAIL_NO_START. * * Each SPI controller can communicate with one or more @spi_device * children. These make a small bus, sharing MOSI, MISO and SCK signals @@ -602,6 +604,7 @@ struct spi_controller { bool auto_runtime_pm; bool cur_msg_prepared; bool cur_msg_mapped; + bool fallback; struct completion xfer_completion; size_t max_dma_len; @@ -847,6 +850,7 @@ extern void spi_res_release(struct spi_controller *ctlr, * back unset and they need the better resolution. * @timestamped_post: See above. The reason why both exist is that these * booleans are also used to keep state in the core SPI logic. + * @error: Error status logged by spi controller driver. * * SPI transfers always write the same number of bytes as they read. * Protocol drivers should always provide @rx_buf and/or @tx_buf. @@ -940,6 +944,9 @@ struct spi_transfer { bool timestamped; struct list_head transfer_list; + +#define SPI_TRANS_FAIL_NO_START BIT(0) + u16 error; }; /** |