From: Sowjanya Komatineni skomatineni@nvidia.com
[ Upstream commit c4fc9e5b28ff787e35137c2cc13316bb11d7657b ]
Fixes: Flush TX and RX FIFOs before start of new transfer and on FIFO overflow or underrun errors.
Signed-off-by: Sowjanya Komatineni skomatineni@nvidia.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/spi/spi-tegra114.c | 39 +++++++++++++++++++++++++++++--------- 1 file changed, 30 insertions(+), 9 deletions(-)
diff --git a/drivers/spi/spi-tegra114.c b/drivers/spi/spi-tegra114.c index b1b726673f85..5114b8008472 100644 --- a/drivers/spi/spi-tegra114.c +++ b/drivers/spi/spi-tegra114.c @@ -499,22 +499,37 @@ static int tegra_spi_start_rx_dma(struct tegra_spi_data *tspi, int len) return 0; }
-static int tegra_spi_start_dma_based_transfer( - struct tegra_spi_data *tspi, struct spi_transfer *t) +static int tegra_spi_flush_fifos(struct tegra_spi_data *tspi) { - u32 val; - unsigned int len; - int ret = 0; + unsigned long timeout = jiffies + HZ; u32 status;
- /* Make sure that Rx and Tx fifo are empty */ status = tegra_spi_readl(tspi, SPI_FIFO_STATUS); if ((status & SPI_FIFO_EMPTY) != SPI_FIFO_EMPTY) { - dev_err(tspi->dev, "Rx/Tx fifo are not empty status 0x%08x\n", - (unsigned)status); - return -EIO; + status |= SPI_RX_FIFO_FLUSH | SPI_TX_FIFO_FLUSH; + tegra_spi_writel(tspi, status, SPI_FIFO_STATUS); + while ((status & SPI_FIFO_EMPTY) != SPI_FIFO_EMPTY) { + status = tegra_spi_readl(tspi, SPI_FIFO_STATUS); + if (time_after(jiffies, timeout)) { + dev_err(tspi->dev, + "timeout waiting for fifo flush\n"); + return -EIO; + } + + udelay(1); + } }
+ return 0; +} + +static int tegra_spi_start_dma_based_transfer( + struct tegra_spi_data *tspi, struct spi_transfer *t) +{ + u32 val; + unsigned int len; + int ret = 0; + val = SPI_DMA_BLK_SET(tspi->curr_dma_words - 1); tegra_spi_writel(tspi, val, SPI_DMA_BLK);
@@ -779,6 +794,9 @@ static int tegra_spi_start_transfer_one(struct spi_device *spi, dev_dbg(tspi->dev, "The def 0x%x and written 0x%x\n", tspi->def_command1_reg, (unsigned)command1);
+ ret = tegra_spi_flush_fifos(tspi); + if (ret < 0) + return ret; if (total_fifo_words > SPI_FIFO_DEPTH) ret = tegra_spi_start_dma_based_transfer(tspi, t); else @@ -876,6 +894,7 @@ static int tegra_spi_transfer_one_message(struct spi_master *master, (tspi->cur_direction & DATA_DIR_RX)) dmaengine_terminate_all(tspi->rx_dma_chan); ret = -EIO; + tegra_spi_flush_fifos(tspi); reset_control_assert(tspi->rst); udelay(2); reset_control_deassert(tspi->rst); @@ -929,6 +948,7 @@ static irqreturn_t handle_cpu_based_xfer(struct tegra_spi_data *tspi) tspi->status_reg); dev_err(tspi->dev, "CpuXfer 0x%08x:0x%08x\n", tspi->command1_reg, tspi->dma_control_reg); + tegra_spi_flush_fifos(tspi); reset_control_assert(tspi->rst); udelay(2); reset_control_deassert(tspi->rst); @@ -1001,6 +1021,7 @@ static irqreturn_t handle_dma_based_xfer(struct tegra_spi_data *tspi) tspi->status_reg); dev_err(tspi->dev, "DmaXfer 0x%08x:0x%08x\n", tspi->command1_reg, tspi->dma_control_reg); + tegra_spi_flush_fifos(tspi); reset_control_assert(tspi->rst); udelay(2); reset_control_deassert(tspi->rst);