1 files changed, 81 insertions, 33 deletions

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 39dc02e366f4..b2dd0a4d2446 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -77,6 +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;
 };
 
@@ -505,8 +510,10 @@ static int mx51_ecspi_prepare_message(struct spi_imx_data *spi_imx,
 				      struct spi_message *msg)
 {
 	struct spi_device *spi = msg->spi;
+	struct spi_transfer *xfer;
 	u32 ctrl = MX51_ECSPI_CTRL_ENABLE;
-	u32 testreg;
+	u32 min_speed_hz = ~0U;
+	u32 testreg, delay;
 	u32 cfg = readl(spi_imx->base + MX51_ECSPI_CONFIG);
 
 	/* set Master or Slave mode */
@@ -567,6 +574,35 @@ static int mx51_ecspi_prepare_message(struct spi_imx_data *spi_imx,
 
 	writel(cfg, spi_imx->base + MX51_ECSPI_CONFIG);
 
+	/*
+	 * Wait until the changes in the configuration register CONFIGREG
+	 * propagate into the hardware. It takes exactly one tick of the
+	 * SCLK clock, but we will wait two SCLK clock just to be sure. The
+	 * effect of the delay it takes for the hardware to apply changes
+	 * is noticable if the SCLK clock run very slow. In such a case, if
+	 * the polarity of SCLK should be inverted, the GPIO ChipSelect might
+	 * be asserted before the SCLK polarity changes, which would disrupt
+	 * the SPI communication as the device on the other end would consider
+	 * the change of SCLK polarity as a clock tick already.
+	 *
+	 * Because spi_imx->spi_bus_clk is only set in bitbang prepare_message
+	 * callback, iterate over all the transfers in spi_message, find the
+	 * one with lowest bus frequency, and use that bus frequency for the
+	 * delay calculation. In case all transfers have speed_hz == 0, then
+	 * min_speed_hz is ~0 and the resulting delay is zero.
+	 */
+	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+		if (!xfer->speed_hz)
+			continue;
+		min_speed_hz = min(xfer->speed_hz, min_speed_hz);
+	}
+
+	delay = (2 * 1000000) / min_speed_hz;
+	if (likely(delay < 10))	/* SCLK is faster than 200 kHz */
+		udelay(delay);
+	else			/* SCLK is _very_ slow */
+		usleep_range(delay, delay + 10);
+
 	return 0;
 }
 
@@ -574,7 +610,7 @@ static int mx51_ecspi_prepare_transfer(struct spi_imx_data *spi_imx,
 				       struct spi_device *spi)
 {
 	u32 ctrl = readl(spi_imx->base + MX51_ECSPI_CTRL);
-	u32 clk, delay;
+	u32 clk;
 
 	/* Clear BL field and set the right value */
 	ctrl &= ~MX51_ECSPI_CTRL_BL_MASK;
@@ -591,39 +627,32 @@ static int mx51_ecspi_prepare_transfer(struct spi_imx_data *spi_imx,
 	ctrl |= mx51_ecspi_clkdiv(spi_imx, spi_imx->spi_bus_clk, &clk);
 	spi_imx->spi_bus_clk = clk;
 
-	if (spi_imx->usedma)
+	/*
+	 * 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);
 
-	/*
-	 * Wait until the changes in the configuration register CONFIGREG
-	 * propagate into the hardware. It takes exactly one tick of the
-	 * SCLK clock, but we will wait two SCLK clock just to be sure. The
-	 * effect of the delay it takes for the hardware to apply changes
-	 * is noticable if the SCLK clock run very slow. In such a case, if
-	 * the polarity of SCLK should be inverted, the GPIO ChipSelect might
-	 * be asserted before the SCLK polarity changes, which would disrupt
-	 * the SPI communication as the device on the other end would consider
-	 * the change of SCLK polarity as a clock tick already.
-	 */
-	delay = (2 * 1000000) / clk;
-	if (likely(delay < 10))	/* SCLK is faster than 100 kHz */
-		udelay(delay);
-	else			/* SCLK is _very_ slow */
-		usleep_range(delay, delay + 10);
-
 	return 0;
 }
 
 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(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);
@@ -1014,6 +1043,23 @@ 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 = IMX51_ECSPI,
+};
+
 static const struct of_device_id spi_imx_dt_ids[] = {
 	{ .compatible = "fsl,imx1-cspi", .data = &imx1_cspi_devtype_data, },
 	{ .compatible = "fsl,imx21-cspi", .data = &imx21_cspi_devtype_data, },
@@ -1022,6 +1068,7 @@ 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);
@@ -1038,12 +1085,8 @@ static void spi_imx_set_burst_len(struct spi_imx_data *spi_imx, int n_bits)
 
 static void spi_imx_push(struct spi_imx_data *spi_imx)
 {
-	unsigned int burst_len, fifo_words;
+	unsigned int burst_len;
 
-	if (spi_imx->dynamic_burst)
-		fifo_words = 4;
-	else
-		fifo_words = spi_imx_bytes_per_word(spi_imx->bits_per_word);
 	/*
 	 * Reload the FIFO when the remaining bytes to be transferred in the
 	 * current burst is 0. This only applies when bits_per_word is a
@@ -1062,7 +1105,7 @@ static void spi_imx_push(struct spi_imx_data *spi_imx)
 
 			spi_imx->remainder = burst_len;
 		} else {
-			spi_imx->remainder = fifo_words;
+			spi_imx->remainder = spi_imx_bytes_per_word(spi_imx->bits_per_word);
 		}
 	}
 
@@ -1070,8 +1113,7 @@ static void spi_imx_push(struct spi_imx_data *spi_imx)
 		if (!spi_imx->count)
 			break;
 		if (spi_imx->dynamic_burst &&
-		    spi_imx->txfifo >= DIV_ROUND_UP(spi_imx->remainder,
-						     fifo_words))
+		    spi_imx->txfifo >= DIV_ROUND_UP(spi_imx->remainder, 4))
 			break;
 		spi_imx->tx(spi_imx);
 		spi_imx->txfifo++;
@@ -1181,6 +1223,7 @@ static int spi_imx_setupxfer(struct spi_device *spi,
 	 * dynamic_burst in that case.
 	 */
 	if (spi_imx->devtype_data->dynamic_burst && !spi_imx->slave_mode &&
+	    !(spi->mode & SPI_CS_WORD) &&
 	    (spi_imx->bits_per_word == 8 ||
 	    spi_imx->bits_per_word == 16 ||
 	    spi_imx->bits_per_word == 32)) {
@@ -1239,10 +1282,6 @@ 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: */
@@ -1616,6 +1655,15 @@ static int spi_imx_probe(struct platform_device *pdev)
 	    is_imx53_ecspi(spi_imx))
 		spi_imx->bitbang.master->mode_bits |= SPI_LOOP | SPI_READY;
 
+	if (is_imx51_ecspi(spi_imx) &&
+	    device_property_read_u32(&pdev->dev, "cs-gpios", NULL))
+		/*
+		 * When using HW-CS implementing SPI_CS_WORD can be done by just
+		 * setting the burst length to the word size. This is
+		 * considerably faster than manually controlling the CS.
+		 */
+		spi_imx->bitbang.master->mode_bits |= SPI_CS_WORD;
+
 	spi_imx->spi_drctl = spi_drctl;
 
 	init_completion(&spi_imx->xfer_done);