[PATCH v4 06/14] spi: imx: fix ERR009165

[Robin Gong]

Change to XCH  mode even in dma mode, please refer to the below
errata:
https://www.nxp.com/docs/en/errata/IMX6DQCE.pdf

Signed-off-by: Robin Gong <yibin.gong@xxxxxxx>
Acked-by: Mark Brown <broonie@xxxxxxxxxx>
---
 drivers/spi/spi-imx.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 09c9a1e..6795910 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -585,8 +585,9 @@ static int mx51_ecspi_prepare_transfer(struct spi_imx_data *spi_imx,
 	ctrl |= mx51_ecspi_clkdiv(spi_imx, t->speed_hz, &clk);
 	spi_imx->spi_bus_clk = clk;
 
+	/* ERR009165: work in XHC mode as PIO */
 	if (spi_imx->usedma)
-		ctrl |= MX51_ECSPI_CTRL_SMC;
+		ctrl &= ~MX51_ECSPI_CTRL_SMC;
 
 	writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
 
@@ -612,12 +613,14 @@ static int mx51_ecspi_prepare_transfer(struct spi_imx_data *spi_imx,
 
 static void mx51_setup_wml(struct spi_imx_data *spi_imx)
 {
+	u32 tx_wml = 0;
+
 	/*
 	 * Configure the DMA register: setup the watermark
 	 * and enable DMA request.
 	 */
 	writel(MX51_ECSPI_DMA_RX_WML(spi_imx->wml - 1) |
-		MX51_ECSPI_DMA_TX_WML(spi_imx->wml) |
+		MX51_ECSPI_DMA_TX_WML(tx_wml) |
 		MX51_ECSPI_DMA_RXT_WML(spi_imx->wml) |
 		MX51_ECSPI_DMA_TEDEN | MX51_ECSPI_DMA_RXDEN |
 		MX51_ECSPI_DMA_RXTDEN, spi_imx->base + MX51_ECSPI_DMA);
@@ -1171,7 +1174,11 @@ static int spi_imx_dma_configure(struct spi_master *master)
 	tx.direction = DMA_MEM_TO_DEV;
 	tx.dst_addr = spi_imx->base_phys + MXC_CSPITXDATA;
 	tx.dst_addr_width = buswidth;
-	tx.dst_maxburst = spi_imx->wml;
+	/*
+	 * For ERR009165 with tx_wml = 0 could enlarge burst size to fifo size
+	 * to speed up fifo filling as possible.
+	 */
+	tx.dst_maxburst = spi_imx->devtype_data->fifo_size;
 	ret = dmaengine_slave_config(master->dma_tx, &tx);
 	if (ret) {
 		dev_err(spi_imx->dev, "TX dma configuration failed with %d\n", ret);
@@ -1265,10 +1272,6 @@ static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx,
 {
 	int ret;
 
-	/* use pio mode for i.mx6dl chip TKT238285 */
-	if (of_machine_is_compatible("fsl,imx6dl"))
-		return 0;
-
 	spi_imx->wml = spi_imx->devtype_data->fifo_size / 2;
 
 	/* Prepare for TX DMA: */
-- 
2.7.4