From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sowjanya Komatineni Subject: [PATCH V2 09/20] spi: tegra114: add 3 wire transfer mode support Date: Thu, 4 Apr 2019 17:14:08 -0700 Message-ID: <1554423259-26056-9-git-send-email-skomatineni@nvidia.com> References: <1554423259-26056-1-git-send-email-skomatineni@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1554423259-26056-1-git-send-email-skomatineni@nvidia.com> Sender: linux-kernel-owner@vger.kernel.org To: thierry.reding@gmail.com, jonathanh@nvidia.com, talho@nvidia.com, skomatineni@nvidia.com, broonie@kernel.org, robh+dt@kernel.org, mark.rutland@arm.com, kyarlagadda@nvidia.com Cc: ldewangan@nvidia.com, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org, devicetree@vger.kernel.org List-Id: devicetree@vger.kernel.org This patch adds 3 wire transfer support to SPI mode list along with its implementation. 3 wire or Bi-directional mode uses only one serial data pin for the transfer. SPI in master mode uses MOSI data line only and MISO data line is not used. Signed-off-by: Sowjanya Komatineni --- drivers/spi/spi-tegra114.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/spi/spi-tegra114.c b/drivers/spi/spi-tegra114.c index 239fb0c8c31f..212bb90aa0cb 100644 --- a/drivers/spi/spi-tegra114.c +++ b/drivers/spi/spi-tegra114.c @@ -755,6 +755,11 @@ static u32 tegra_spi_setup_transfer_one(struct spi_device *spi, else command1 &= ~SPI_LSBIT_FE; + if (spi->mode & SPI_3WIRE) + command1 |= SPI_BIDIROE; + else + command1 &= ~SPI_BIDIROE; + if (tspi->cs_control) { if (tspi->cs_control != spi) tegra_spi_writel(tspi, command1, SPI_COMMAND1); @@ -1159,7 +1164,7 @@ static int tegra_spi_probe(struct platform_device *pdev) /* the spi->mode bits understood by this driver: */ master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST | - SPI_TX_DUAL | SPI_RX_DUAL; + SPI_TX_DUAL | SPI_RX_DUAL | SPI_3WIRE; master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32); master->setup = tegra_spi_setup; master->transfer_one_message = tegra_spi_transfer_one_message; -- 2.7.4