[PATCH v8 08/13] spi: imx: remove ERR009165 workaround on i.mx6ul

[Robin Gong <yibin.gong@xxxxxxx>]

ERR009165 fixed on i.mx6ul/6ull/6sll. All other i.mx6/7 and
i.mx8m/8mm still need this errata. Please refer to nxp official
errata document from https://www.nxp.com/ .

For removing workaround on those chips. Add new i.mx6ul type.

Signed-off-by: Robin Gong <yibin.gong@xxxxxxx>
Acked-by: Mark Brown <broonie@xxxxxxxxxx>
---
 drivers/spi/spi-imx.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 54 insertions(+), 5 deletions(-)

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 8f758db..9ac9222 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -57,6 +57,7 @@ enum spi_imx_devtype {
 	IMX35_CSPI,	/* CSPI on all i.mx except above */
 	IMX51_ECSPI,	/* ECSPI on i.mx51 */
 	IMX53_ECSPI,	/* ECSPI on i.mx53 and later */
+	IMX6UL_ECSPI,	/* ERR009165 fix from i.mx6ul */
 };
 
 struct spi_imx_data;
@@ -76,6 +77,11 @@ struct spi_imx_devtype_data {
 	bool has_slavemode;
 	unsigned int fifo_size;
 	bool dynamic_burst;
+	/*
+	 * ERR009165 fixed or not:
+	 * https://www.nxp.com/docs/en/errata/IMX6DQCE.pdf
+	 */
+	bool tx_glitch_fixed;
 	enum spi_imx_devtype devtype;
 };
 
@@ -132,6 +138,11 @@ static inline int is_imx51_ecspi(struct spi_imx_data *d)
 	return d->devtype_data->devtype == IMX51_ECSPI;
 }
 
+static inline int is_imx6ul_ecspi(struct spi_imx_data *d)
+{
+	return d->devtype_data->devtype == IMX6UL_ECSPI;
+}
+
 static inline int is_imx53_ecspi(struct spi_imx_data *d)
 {
 	return d->devtype_data->devtype == IMX53_ECSPI;
@@ -591,8 +602,14 @@ 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 */
-	ctrl &= ~MX51_ECSPI_CTRL_SMC;
+	/*
+	 * ERR009165: work in XHC mode instead of SMC as PIO on the chips
+	 * before i.mx6ul.
+	 */
+	if (spi_imx->usedma && spi_imx->devtype_data->tx_glitch_fixed)
+		ctrl |= MX51_ECSPI_CTRL_SMC;
+	else
+		ctrl &= ~MX51_ECSPI_CTRL_SMC;
 
 	writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
 
@@ -618,12 +635,16 @@ 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;
+
+	if (spi_imx->devtype_data->tx_glitch_fixed)
+		tx_wml = spi_imx->wml;
 	/*
 	 * 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(0) |
+		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);
@@ -1017,6 +1038,23 @@ static struct spi_imx_devtype_data imx53_ecspi_devtype_data = {
 	.devtype = IMX53_ECSPI,
 };
 
+static struct spi_imx_devtype_data imx6ul_ecspi_devtype_data = {
+	.intctrl = mx51_ecspi_intctrl,
+	.prepare_message = mx51_ecspi_prepare_message,
+	.prepare_transfer = mx51_ecspi_prepare_transfer,
+	.trigger = mx51_ecspi_trigger,
+	.rx_available = mx51_ecspi_rx_available,
+	.reset = mx51_ecspi_reset,
+	.setup_wml = mx51_setup_wml,
+	.fifo_size = 64,
+	.has_dmamode = true,
+	.dynamic_burst = true,
+	.has_slavemode = true,
+	.tx_glitch_fixed = true,
+	.disable = mx51_ecspi_disable,
+	.devtype = IMX6UL_ECSPI,
+};
+
 static const struct platform_device_id spi_imx_devtype[] = {
 	{
 		.name = "imx1-cspi",
@@ -1040,6 +1078,9 @@ static const struct platform_device_id spi_imx_devtype[] = {
 		.name = "imx53-ecspi",
 		.driver_data = (kernel_ulong_t) &imx53_ecspi_devtype_data,
 	}, {
+		.name = "imx6ul-ecspi",
+		.driver_data = (kernel_ulong_t) &imx6ul_ecspi_devtype_data,
+	}, {
 		/* sentinel */
 	}
 };
@@ -1052,6 +1093,7 @@ static const struct of_device_id spi_imx_dt_ids[] = {
 	{ .compatible = "fsl,imx35-cspi", .data = &imx35_cspi_devtype_data, },
 	{ .compatible = "fsl,imx51-ecspi", .data = &imx51_ecspi_devtype_data, },
 	{ .compatible = "fsl,imx53-ecspi", .data = &imx53_ecspi_devtype_data, },
+	{ .compatible = "fsl,imx6ul-ecspi", .data = &imx6ul_ecspi_devtype_data, },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, spi_imx_dt_ids);
@@ -1179,7 +1221,14 @@ 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_THRESHOLD=0 could enlarge burst size to fifo
+	 * size to speed up fifo filling as possible.
+	 */
+	if (spi_imx->devtype_data->tx_glitch_fixed)
+		tx.dst_maxburst = spi_imx->wml;
+	else
+		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);
@@ -1678,7 +1727,7 @@ static int spi_imx_probe(struct platform_device *pdev)
 	spi_imx->bitbang.master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH \
 					     | SPI_NO_CS;
 	if (is_imx35_cspi(spi_imx) || is_imx51_ecspi(spi_imx) ||
-	    is_imx53_ecspi(spi_imx))
+	    is_imx53_ecspi(spi_imx) || is_imx6ul_ecspi(spi_imx))
 		spi_imx->bitbang.master->mode_bits |= SPI_LOOP | SPI_READY;
 
 	spi_imx->spi_drctl = spi_drctl;
-- 
2.7.4