1 files changed, 101 insertions, 88 deletions

diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
index 158cb48c0f4a..298c22def165 100644
--- a/drivers/spi/spi-fsl-dspi.c
+++ b/drivers/spi/spi-fsl-dspi.c
@@ -72,6 +72,7 @@
 #define SPI_RSER			0x30
 #define SPI_RSER_TCFQE			BIT(31)
 #define SPI_RSER_EOQFE			BIT(28)
+#define SPI_RSER_CMDTCFE		BIT(23)
 
 #define SPI_PUSHR			0x34
 #define SPI_PUSHR_CMD_CONT		BIT(15)
@@ -114,14 +115,13 @@ struct chip_data {
 
 enum dspi_trans_mode {
 	DSPI_EOQ_MODE = 0,
-	DSPI_TCFQ_MODE,
+	DSPI_XSPI_MODE,
 	DSPI_DMA_MODE,
 };
 
 struct fsl_dspi_devtype_data {
 	enum dspi_trans_mode	trans_mode;
 	u8			max_clock_factor;
-	bool			xspi_mode;
 	int			fifo_size;
 	int			dma_bufsize;
 };
@@ -147,37 +147,32 @@ static const struct fsl_dspi_devtype_data devtype_data[] = {
 	},
 	[LS1021A] = {
 		/* Has A-011218 DMA erratum */
-		.trans_mode		= DSPI_TCFQ_MODE,
+		.trans_mode		= DSPI_XSPI_MODE,
 		.max_clock_factor	= 8,
-		.xspi_mode		= true,
 		.fifo_size		= 4,
 	},
 	[LS1012A] = {
 		/* Has A-011218 DMA erratum */
-		.trans_mode		= DSPI_TCFQ_MODE,
+		.trans_mode		= DSPI_XSPI_MODE,
 		.max_clock_factor	= 8,
-		.xspi_mode		= true,
 		.fifo_size		= 16,
 	},
 	[LS1043A] = {
 		/* Has A-011218 DMA erratum */
-		.trans_mode		= DSPI_TCFQ_MODE,
+		.trans_mode		= DSPI_XSPI_MODE,
 		.max_clock_factor	= 8,
-		.xspi_mode		= true,
 		.fifo_size		= 16,
 	},
 	[LS1046A] = {
 		/* Has A-011218 DMA erratum */
-		.trans_mode		= DSPI_TCFQ_MODE,
+		.trans_mode		= DSPI_XSPI_MODE,
 		.max_clock_factor	= 8,
-		.xspi_mode		= true,
 		.fifo_size		= 16,
 	},
 	[LS2080A] = {
 		.trans_mode		= DSPI_DMA_MODE,
 		.dma_bufsize		= 8,
 		.max_clock_factor	= 8,
-		.xspi_mode		= true,
 		.fifo_size		= 4,
 	},
 	[LS2085A] = {
@@ -190,7 +185,6 @@ static const struct fsl_dspi_devtype_data devtype_data[] = {
 		.trans_mode		= DSPI_DMA_MODE,
 		.dma_bufsize		= 8,
 		.max_clock_factor	= 8,
-		.xspi_mode		= true,
 		.fifo_size		= 4,
 	},
 	[MCF5441X] = {
@@ -233,7 +227,6 @@ struct fsl_dspi {
 	size_t					len;
 	const void				*tx;
 	void					*rx;
-	void					*rx_end;
 	u16					tx_cmd;
 	u8					bits_per_word;
 	u8					bytes_per_word;
@@ -243,6 +236,8 @@ struct fsl_dspi {
 	u32					waitflags;
 
 	struct fsl_dspi_dma			*dma;
+
+	int					words_in_flight;
 };
 
 /*
@@ -610,7 +605,17 @@ static void dspi_pushr_cmd_write(struct fsl_dspi *dspi)
 {
 	u16 cmd = dspi->tx_cmd;
 
-	if (dspi->len > 0)
+	/*
+	 * The only time when the PCS doesn't need continuation after this word
+	 * is when it's last. We need to look ahead, because we actually call
+	 * dspi_pop_tx (the function that decrements dspi->len) _after_
+	 * dspi_pushr_cmd_write with XSPI mode. As for how much in advance? One
+	 * word is enough. If there's more to transmit than that,
+	 * dspi_xspi_write will know to split the FIFO writes in 2, and
+	 * generate a new PUSHR command with the final word that will have PCS
+	 * deasserted (not continued) here.
+	 */
+	if (dspi->len > dspi->bytes_per_word)
 		cmd |= SPI_PUSHR_CMD_CONT;
 	regmap_write(dspi->regmap_pushr, PUSHR_CMD, cmd);
 }
@@ -620,93 +625,115 @@ static void dspi_pushr_txdata_write(struct fsl_dspi *dspi, u16 txdata)
 	regmap_write(dspi->regmap_pushr, PUSHR_TX, txdata);
 }
 
-static void dspi_tcfq_write(struct fsl_dspi *dspi)
+static void dspi_xspi_write(struct fsl_dspi *dspi, int cnt)
 {
-	/* Clear transfer count */
-	dspi->tx_cmd |= SPI_PUSHR_CMD_CTCNT;
+	regmap_write(dspi->regmap, SPI_CTARE(0),
+		     SPI_FRAME_EBITS(dspi->bits_per_word) |
+		     SPI_CTARE_DTCP(cnt));
 
-	if (dspi->devtype_data->xspi_mode && dspi->bits_per_word > 16) {
-		/* Write the CMD FIFO entry first, and then the two
-		 * corresponding TX FIFO entries.
-		 */
+	/*
+	 * Write the CMD FIFO entry first, and then the two
+	 * corresponding TX FIFO entries (or one...).
+	 */
+	dspi_pushr_cmd_write(dspi);
+
+	/* Fill TX FIFO with as many transfers as possible */
+	while (cnt--) {
 		u32 data = dspi_pop_tx(dspi);
 
-		dspi_pushr_cmd_write(dspi);
 		dspi_pushr_txdata_write(dspi, data & 0xFFFF);
-		dspi_pushr_txdata_write(dspi, data >> 16);
-	} else {
-		/* Write one entry to both TX FIFO and CMD FIFO
-		 * simultaneously.
-		 */
-		dspi_pushr_write(dspi);
+		if (dspi->bits_per_word > 16)
+			dspi_pushr_txdata_write(dspi, data >> 16);
 	}
 }
 
-static u32 dspi_popr_read(struct fsl_dspi *dspi)
+static void dspi_xspi_fifo_write(struct fsl_dspi *dspi)
 {
-	u32 rxdata = 0;
+	int num_fifo_entries = dspi->devtype_data->fifo_size;
+	int bytes_in_flight;
 
-	regmap_read(dspi->regmap, SPI_POPR, &rxdata);
-	return rxdata;
-}
+	/* In XSPI mode each 32-bit word occupies 2 TX FIFO entries */
+	if (dspi->bits_per_word > 16)
+		num_fifo_entries /= 2;
 
-static void dspi_tcfq_read(struct fsl_dspi *dspi)
-{
-	dspi_push_rx(dspi, dspi_popr_read(dspi));
+	dspi->words_in_flight = dspi->len / dspi->bytes_per_word;
+
+	if (dspi->words_in_flight > num_fifo_entries)
+		dspi->words_in_flight = num_fifo_entries;
+
+	bytes_in_flight = dspi->words_in_flight * dspi->bytes_per_word;
+
+	/*
+	 * If the PCS needs to de-assert (i.e. we're at the end of the buffer
+	 * and cs_change does not want the PCS to stay on), then we need a new
+	 * PUSHR command, since this one (for the body of the buffer)
+	 * necessarily has the CONT bit set.
+	 * So send one word less during this go, to force a split and a command
+	 * with a single word next time, when CONT will be unset.
+	 */
+	if (bytes_in_flight == dspi->len && dspi->words_in_flight > 1 &&
+	    !(dspi->tx_cmd & SPI_PUSHR_CMD_CONT))
+		dspi->words_in_flight--;
+
+	dspi_xspi_write(dspi, dspi->words_in_flight);
 }
 
-static void dspi_eoq_write(struct fsl_dspi *dspi)
+static void dspi_eoq_fifo_write(struct fsl_dspi *dspi)
 {
-	int fifo_size = dspi->devtype_data->fifo_size;
+	int num_fifo_entries = dspi->devtype_data->fifo_size;
 	u16 xfer_cmd = dspi->tx_cmd;
 
+	dspi->words_in_flight = num_fifo_entries;
+
 	/* Fill TX FIFO with as many transfers as possible */
-	while (dspi->len && fifo_size--) {
+	while (dspi->len && num_fifo_entries--) {
 		dspi->tx_cmd = xfer_cmd;
 		/* Request EOQF for last transfer in FIFO */
-		if (dspi->len == dspi->bytes_per_word || fifo_size == 0)
+		if (dspi->len == dspi->bytes_per_word || num_fifo_entries == 0)
 			dspi->tx_cmd |= SPI_PUSHR_CMD_EOQ;
-		/* Clear transfer count for first transfer in FIFO */
-		if (fifo_size == (dspi->devtype_data->fifo_size - 1))
-			dspi->tx_cmd |= SPI_PUSHR_CMD_CTCNT;
 		/* Write combined TX FIFO and CMD FIFO entry */
 		dspi_pushr_write(dspi);
 	}
 }
 
-static void dspi_eoq_read(struct fsl_dspi *dspi)
+static u32 dspi_popr_read(struct fsl_dspi *dspi)
 {
-	int fifo_size = dspi->devtype_data->fifo_size;
+	u32 rxdata = 0;
 
+	regmap_read(dspi->regmap, SPI_POPR, &rxdata);
+	return rxdata;
+}
+
+static void dspi_fifo_read(struct fsl_dspi *dspi)
+{
 	/* Read one FIFO entry and push to rx buffer */
-	while ((dspi->rx < dspi->rx_end) && fifo_size--)
+	while (dspi->words_in_flight--)
 		dspi_push_rx(dspi, dspi_popr_read(dspi));
 }
 
+static void dspi_fifo_write(struct fsl_dspi *dspi)
+{
+	if (dspi->devtype_data->trans_mode == DSPI_EOQ_MODE)
+		dspi_eoq_fifo_write(dspi);
+	else
+		dspi_xspi_fifo_write(dspi);
+}
+
 static int dspi_rxtx(struct fsl_dspi *dspi)
 {
+	struct spi_transfer *xfer = dspi->cur_transfer;
 	struct spi_message *msg = dspi->cur_msg;
-	enum dspi_trans_mode trans_mode;
-	u16 spi_tcnt;
-	u32 spi_tcr;
+	int bytes_sent;
+
+	/* Update total number of bytes that were transferred */
+	bytes_sent = dspi->words_in_flight * dspi->bytes_per_word;
+	msg->actual_length += bytes_sent;
+	dspi->progress += bytes_sent / DIV_ROUND_UP(xfer->bits_per_word, 8);
 
 	spi_take_timestamp_post(dspi->ctlr, dspi->cur_transfer,
 				dspi->progress, !dspi->irq);
 
-	/* Get transfer counter (in number of SPI transfers). It was
-	 * reset to 0 when transfer(s) were started.
-	 */
-	regmap_read(dspi->regmap, SPI_TCR, &spi_tcr);
-	spi_tcnt = SPI_TCR_GET_TCNT(spi_tcr);
-	/* Update total number of bytes that were transferred */
-	msg->actual_length += spi_tcnt * dspi->bytes_per_word;
-	dspi->progress += spi_tcnt;
-
-	trans_mode = dspi->devtype_data->trans_mode;
-	if (trans_mode == DSPI_EOQ_MODE)
-		dspi_eoq_read(dspi);
-	else if (trans_mode == DSPI_TCFQ_MODE)
-		dspi_tcfq_read(dspi);
+	dspi_fifo_read(dspi);
 
 	if (!dspi->len)
 		/* Success! */
@@ -715,10 +742,7 @@ static int dspi_rxtx(struct fsl_dspi *dspi)
 	spi_take_timestamp_pre(dspi->ctlr, dspi->cur_transfer,
 			       dspi->progress, !dspi->irq);
 
-	if (trans_mode == DSPI_EOQ_MODE)
-		dspi_eoq_write(dspi);
-	else if (trans_mode == DSPI_TCFQ_MODE)
-		dspi_tcfq_write(dspi);
+	dspi_fifo_write(dspi);
 
 	return -EINPROGRESS;
 }
@@ -732,7 +756,7 @@ static int dspi_poll(struct fsl_dspi *dspi)
 		regmap_read(dspi->regmap, SPI_SR, &spi_sr);
 		regmap_write(dspi->regmap, SPI_SR, spi_sr);
 
-		if (spi_sr & (SPI_SR_EOQF | SPI_SR_TCFQF))
+		if (spi_sr & (SPI_SR_EOQF | SPI_SR_CMDTCF))
 			break;
 	} while (--tries);
 
@@ -750,7 +774,7 @@ static irqreturn_t dspi_interrupt(int irq, void *dev_id)
 	regmap_read(dspi->regmap, SPI_SR, &spi_sr);
 	regmap_write(dspi->regmap, SPI_SR, spi_sr);
 
-	if (!(spi_sr & SPI_SR_EOQF))
+	if (!(spi_sr & (SPI_SR_EOQF | SPI_SR_CMDTCF)))
 		return IRQ_NONE;
 
 	if (dspi_rxtx(dspi) == 0) {
@@ -798,7 +822,6 @@ static int dspi_transfer_one_message(struct spi_controller *ctlr,
 
 		dspi->tx = transfer->tx_buf;
 		dspi->rx = transfer->rx_buf;
-		dspi->rx_end = dspi->rx + transfer->len;
 		dspi->len = transfer->len;
 		dspi->progress = 0;
 		/* Validated transfer specific frame size (defaults applied) */
@@ -811,10 +834,6 @@ static int dspi_transfer_one_message(struct spi_controller *ctlr,
 		regmap_write(dspi->regmap, SPI_CTAR(0),
 			     dspi->cur_chip->ctar_val |
 			     SPI_FRAME_BITS(transfer->bits_per_word));
-		if (dspi->devtype_data->xspi_mode)
-			regmap_write(dspi->regmap, SPI_CTARE(0),
-				     SPI_FRAME_EBITS(transfer->bits_per_word) |
-				     SPI_CTARE_DTCP(1));
 
 		spi_take_timestamp_pre(dspi->ctlr, dspi->cur_transfer,
 				       dspi->progress, !dspi->irq);
@@ -823,11 +842,11 @@ static int dspi_transfer_one_message(struct spi_controller *ctlr,
 		switch (trans_mode) {
 		case DSPI_EOQ_MODE:
 			regmap_write(dspi->regmap, SPI_RSER, SPI_RSER_EOQFE);
-			dspi_eoq_write(dspi);
+			dspi_fifo_write(dspi);
 			break;
-		case DSPI_TCFQ_MODE:
-			regmap_write(dspi->regmap, SPI_RSER, SPI_RSER_TCFQE);
-			dspi_tcfq_write(dspi);
+		case DSPI_XSPI_MODE:
+			regmap_write(dspi->regmap, SPI_RSER, SPI_RSER_CMDTCFE);
+			dspi_fifo_write(dspi);
 			break;
 		case DSPI_DMA_MODE:
 			regmap_write(dspi->regmap, SPI_RSER,
@@ -1053,16 +1072,13 @@ static void dspi_init(struct fsl_dspi *dspi)
 {
 	unsigned int mcr = SPI_MCR_PCSIS;
 
-	if (dspi->devtype_data->xspi_mode)
+	if (dspi->devtype_data->trans_mode == DSPI_XSPI_MODE)
 		mcr |= SPI_MCR_XSPI;
 	if (!spi_controller_is_slave(dspi->ctlr))
 		mcr |= SPI_MCR_MASTER;
 
 	regmap_write(dspi->regmap, SPI_MCR, mcr);
 	regmap_write(dspi->regmap, SPI_SR, SPI_SR_CLEAR);
-	if (dspi->devtype_data->xspi_mode)
-		regmap_write(dspi->regmap, SPI_CTARE(0),
-			     SPI_CTARE_FMSZE(0) | SPI_CTARE_DTCP(1));
 }
 
 static int dspi_slave_abort(struct spi_master *master)
@@ -1162,7 +1178,7 @@ static int dspi_probe(struct platform_device *pdev)
 		}
 	}
 
-	if (dspi->devtype_data->xspi_mode)
+	if (dspi->devtype_data->trans_mode == DSPI_XSPI_MODE)
 		ctlr->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
 	else
 		ctlr->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
@@ -1174,7 +1190,7 @@ static int dspi_probe(struct platform_device *pdev)
 		goto out_ctlr_put;
 	}
 
-	if (dspi->devtype_data->xspi_mode)
+	if (dspi->devtype_data->trans_mode == DSPI_XSPI_MODE)
 		regmap_config = &dspi_xspi_regmap_config[0];
 	else
 		regmap_config = &dspi_regmap_config;
@@ -1186,7 +1202,7 @@ static int dspi_probe(struct platform_device *pdev)
 		goto out_ctlr_put;
 	}
 
-	if (dspi->devtype_data->xspi_mode) {
+	if (dspi->devtype_data->trans_mode == DSPI_XSPI_MODE) {
 		dspi->regmap_pushr = devm_regmap_init_mmio(
 			&pdev->dev, base + SPI_PUSHR,
 			&dspi_xspi_regmap_config[1]);
@@ -1211,9 +1227,6 @@ static int dspi_probe(struct platform_device *pdev)
 
 	dspi_init(dspi);
 
-	if (dspi->devtype_data->trans_mode == DSPI_TCFQ_MODE)
-		goto poll_mode;
-
 	dspi->irq = platform_get_irq(pdev, 0);
 	if (dspi->irq <= 0) {
 		dev_info(&pdev->dev,