diff options
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/spi-dw-mid.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/drivers/spi/spi-dw-mid.c b/drivers/spi/spi-dw-mid.c index 355b641c4483..846e3db91329 100644 --- a/drivers/spi/spi-dw-mid.c +++ b/drivers/spi/spi-dw-mid.c @@ -19,6 +19,7 @@ #include <linux/pci.h> #include <linux/platform_data/dma-dw.h> +#define WAIT_RETRIES 5 #define RX_BUSY 0 #define TX_BUSY 1 @@ -171,6 +172,33 @@ static int dw_spi_dma_wait(struct dw_spi *dws, struct spi_transfer *xfer) return 0; } +static inline bool dw_spi_dma_tx_busy(struct dw_spi *dws) +{ + return !(dw_readl(dws, DW_SPI_SR) & SR_TF_EMPT); +} + +static int dw_spi_dma_wait_tx_done(struct dw_spi *dws, + struct spi_transfer *xfer) +{ + int retry = WAIT_RETRIES; + struct spi_delay delay; + u32 nents; + + nents = dw_readl(dws, DW_SPI_TXFLR); + delay.unit = SPI_DELAY_UNIT_SCK; + delay.value = nents * dws->n_bytes * BITS_PER_BYTE; + + while (dw_spi_dma_tx_busy(dws) && retry--) + spi_delay_exec(&delay, xfer); + + if (retry < 0) { + dev_err(&dws->master->dev, "Tx hanged up\n"); + return -EIO; + } + + return 0; +} + /* * dws->dma_chan_busy is set before the dma transfer starts, callback for tx * channel will clear a corresponding bit. @@ -324,6 +352,12 @@ static int mid_spi_dma_transfer(struct dw_spi *dws, struct spi_transfer *xfer) if (ret) return ret; + if (txdesc && dws->master->cur_msg->status == -EINPROGRESS) { + ret = dw_spi_dma_wait_tx_done(dws, xfer); + if (ret) + return ret; + } + return 0; } |