Added Dual mode half duplex Rx and Tx support to Allwinner sun6i/sun8i SPI driver. Main changes is related to SUN6I_BURST_CTL_CNT_REG register. SPI transmit is in Dual mode if STC (Master Single Mode Transmit Counter) is 0 and DRM (Master Dual Mode RX Enable) is not set. SPI receive is in Dual mode if DRM (Master Dual Mode RX Enable) is set. Tested on Allwinner V3s (sun8i) CPU.
Signed-off-by: Maksims Matjakubovs <[email protected]> --- drivers/spi/spi-sun6i.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c index 8533f4e..2da52ed 100644 --- a/drivers/spi/spi-sun6i.c +++ b/drivers/spi/spi-sun6i.c @@ -84,6 +84,7 @@ #define SUN6I_BURST_CTL_CNT_REG 0x38 #define SUN6I_BURST_CTL_CNT_STC(cnt) ((cnt) & SUN6I_MAX_XFER_SIZE) +#define SUN6I_BURST_CTL_CNT_DRM BIT(28) #define SUN6I_TXDATA_REG 0x200 #define SUN6I_RXDATA_REG 0x300 @@ -312,6 +313,8 @@ static int sun6i_spi_transfer_one(struct spi_master *master, sun6i_spi_write(sspi, SUN6I_BURST_CNT_REG, SUN6I_BURST_CNT(tfr->len)); sun6i_spi_write(sspi, SUN6I_XMIT_CNT_REG, SUN6I_XMIT_CNT(tx_len)); sun6i_spi_write(sspi, SUN6I_BURST_CTL_CNT_REG, + (tfr->tx_nbits == SPI_NBITS_DUAL) ? 0 : + (tfr->rx_nbits == SPI_NBITS_DUAL) ? SUN6I_BURST_CTL_CNT_DRM : SUN6I_BURST_CTL_CNT_STC(tx_len)); /* Fill the TX FIFO */ @@ -480,7 +483,8 @@ static int sun6i_spi_probe(struct platform_device *pdev) master->set_cs = sun6i_spi_set_cs; master->transfer_one = sun6i_spi_transfer_one; master->num_chipselect = 4; - master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST; + master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST | + SPI_RX_DUAL | SPI_TX_DUAL; master->bits_per_word_mask = SPI_BPW_MASK(8); master->dev.of_node = pdev->dev.of_node; master->auto_runtime_pm = true; -- 2.7.4
