spi: tegra114: dump SPI registers during timeout

This patch dumps SPI registers on transfer error or timeout for debug
purpose.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-tegra114.c

@@ -874,6 +874,20 @@ static void tegra_spi_transfer_end(struct spi_device *spi)
 	tegra_spi_writel(tspi, tspi->def_command1_reg, SPI_COMMAND1);
 }
 
+static void tegra_spi_dump_regs(struct tegra_spi_data *tspi)
+{
+	dev_dbg(tspi->dev, "============ SPI REGISTER DUMP ============\n");
+	dev_dbg(tspi->dev, "Command1:    0x%08x | Command2:    0x%08x\n",
+		tegra_spi_readl(tspi, SPI_COMMAND1),
+		tegra_spi_readl(tspi, SPI_COMMAND2));
+	dev_dbg(tspi->dev, "DMA_CTL:     0x%08x | DMA_BLK:     0x%08x\n",
+		tegra_spi_readl(tspi, SPI_DMA_CTL),
+		tegra_spi_readl(tspi, SPI_DMA_BLK));
+	dev_dbg(tspi->dev, "TRANS_STAT:  0x%08x | FIFO_STATUS: 0x%08x\n",
+		tegra_spi_readl(tspi, SPI_TRANS_STATUS),
+		tegra_spi_readl(tspi, SPI_FIFO_STATUS));
+}
+
 static int tegra_spi_transfer_one_message(struct spi_master *master,
 			struct spi_message *msg)
 {
@@ -920,6 +934,7 @@ 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_dump_regs(tspi);
 			tegra_spi_flush_fifos(tspi);
 			reset_control_assert(tspi->rst);
 			udelay(2);
@@ -930,6 +945,7 @@ static int tegra_spi_transfer_one_message(struct spi_master *master,
 		if (tspi->tx_status ||  tspi->rx_status) {
 			dev_err(tspi->dev, "Error in Transfer\n");
 			ret = -EIO;
+			tegra_spi_dump_regs(tspi);
 			goto complete_xfer;
 		}
 		msg->actual_length += xfer->len;
@@ -971,6 +987,7 @@ 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_dump_regs(tspi);
 		tegra_spi_flush_fifos(tspi);
 		complete(&tspi->xfer_completion);
 		spin_unlock_irqrestore(&tspi->lock, flags);
@@ -1045,6 +1062,7 @@ 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_dump_regs(tspi);
 		tegra_spi_flush_fifos(tspi);
 		complete(&tspi->xfer_completion);
 		spin_unlock_irqrestore(&tspi->lock, flags);