[PATCH v3] spi: spi-fsl-dspi: Enable TCF interrupt mode support

[PATCH v3] spi: spi-fsl-dspi: Enable TCF interrupt mode support

[Haikun Wang]

DSPI module has two optional interrupts when complete data transfer.
One is EOQ interrupt, the other one is TCF interrupt.
EOQ indicates a queue of data frame has been transmitted.
TCF indicates a frame has been transmitted.
This patch enable support TCF mode.
Driver binds a correct interrupt mode to every compatible string.
User should use the correct compatible string in the dts node.

Signed-off-by: Haikun Wang <haikun.wang-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
---

Changes in v3:
- Using different compatible strings instead of a individual
  property to select the interrupt mode

Changes in v2:
- Remove global variable g_actual_length
- Add "dspi->dataflags &= ~TRAN_STATE_WORD_ODD_NUM" 
  if dataflags has TRAN_STATE_WORD_ODD_NUM in IRQ handler
- Move single byte chacking inside while loop in function dspi_eoq_write 

Changes in v1: None
 drivers/spi/spi-fsl-dspi.c | 214 +++++++++++++++++++++++++++++----------------
 1 file changed, 139 insertions(+), 75 deletions(-)

diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
index 5fe54cd..ce2062a 100644
--- a/drivers/spi/spi-fsl-dspi.c
+++ b/drivers/spi/spi-fsl-dspi.c
@@ -67,9 +67,11 @@
 
 #define SPI_SR			0x2c
 #define SPI_SR_EOQF		0x10000000
+#define SPI_SR_TCFQF		0x80000000
 
 #define SPI_RSER		0x30
 #define SPI_RSER_EOQFE		0x10000000
+#define SPI_RSER_TCFQE		0x80000000
 
 #define SPI_PUSHR		0x34
 #define SPI_PUSHR_CONT		(1 << 31)
@@ -108,6 +110,27 @@ struct chip_data {
 	u16 void_write_data;
 };
 
+enum dspi_trans_mode {
+	DSPI_EOQ_MODE = 0,
+	DSPI_TCFQ_MODE,
+};
+
+struct fsl_dspi_devtype_data {
+	enum dspi_trans_mode trans_mode;
+};
+
+static const struct fsl_dspi_devtype_data vf610_data = {
+	.trans_mode = DSPI_EOQ_MODE,
+};
+
+static const struct fsl_dspi_devtype_data ls1021a_v1_data = {
+	.trans_mode = DSPI_TCFQ_MODE,
+};
+
+static const struct fsl_dspi_devtype_data ls2085a_data = {
+	.trans_mode = DSPI_TCFQ_MODE,
+};
+
 struct fsl_dspi {
 	struct spi_master	*master;
 	struct platform_device	*pdev;
@@ -128,6 +151,7 @@ struct fsl_dspi {
 	u8			cs;
 	u16			void_write_data;
 	u32			cs_change;
+	struct fsl_dspi_devtype_data *devtype_data;
 
 	wait_queue_head_t	waitq;
 	u32			waitflags;
@@ -213,63 +237,61 @@ static void ns_delay_scale(char *psc, char *sc, int delay_ns,
 	}
 }
 
-static int dspi_transfer_write(struct fsl_dspi *dspi)
+static u32 dspi_data_to_pushr(struct fsl_dspi *dspi, int tx_word)
 {
-	int tx_count = 0;
-	int tx_word;
 	u16 d16;
-	u8  d8;
-	u32 dspi_pushr = 0;
-	int first = 1;
 
-	tx_word = is_double_byte_mode(dspi);
+	if (!(dspi->dataflags & TRAN_STATE_TX_VOID))
+		d16 = tx_word ? *(u16 *)dspi->tx : *(u8 *)dspi->tx;
+	else
+		d16 = dspi->void_write_data;
 
-	/* If we are in word mode, but only have a single byte to transfer
-	 * then switch to byte mode temporarily.  Will switch back at the
-	 * end of the transfer.
-	 */
-	if (tx_word && (dspi->len == 1)) {
-		dspi->dataflags |= TRAN_STATE_WORD_ODD_NUM;
-		regmap_update_bits(dspi->regmap, SPI_CTAR(dspi->cs),
-				SPI_FRAME_BITS_MASK, SPI_FRAME_BITS(8));
-		tx_word = 0;
-	}
+	dspi->tx += tx_word + 1;
+	dspi->len -= tx_word + 1;
 
-	while (dspi->len && (tx_count < DSPI_FIFO_SIZE)) {
-		if (tx_word) {
-			if (dspi->len == 1)
-				break;
+	return	SPI_PUSHR_TXDATA(d16) |
+		SPI_PUSHR_PCS(dspi->cs) |
+		SPI_PUSHR_CTAS(dspi->cs) |
+		SPI_PUSHR_CONT;
+}
 
-			if (!(dspi->dataflags & TRAN_STATE_TX_VOID)) {
-				d16 = *(u16 *)dspi->tx;
-				dspi->tx += 2;
-			} else {
-				d16 = dspi->void_write_data;
-			}
+static void dspi_data_from_popr(struct fsl_dspi *dspi, int rx_word)
+{
+	u16 d;
+	unsigned int val;
 
-			dspi_pushr = SPI_PUSHR_TXDATA(d16) |
-				SPI_PUSHR_PCS(dspi->cs) |
-				SPI_PUSHR_CTAS(dspi->cs) |
-				SPI_PUSHR_CONT;
+	regmap_read(dspi->regmap, SPI_POPR, &val);
+	d = SPI_POPR_RXDATA(val);
 
-			dspi->len -= 2;
-		} else {
-			if (!(dspi->dataflags & TRAN_STATE_TX_VOID)) {
+	if (!(dspi->dataflags & TRAN_STATE_RX_VOID))
+		rx_word ? (*(u16 *)dspi->rx = d) : (*(u8 *)dspi->rx = d);
 
-				d8 = *(u8 *)dspi->tx;
-				dspi->tx++;
-			} else {
-				d8 = (u8)dspi->void_write_data;
-			}
+	dspi->rx += rx_word + 1;
+}
 
-			dspi_pushr = SPI_PUSHR_TXDATA(d8) |
-				SPI_PUSHR_PCS(dspi->cs) |
-				SPI_PUSHR_CTAS(dspi->cs) |
-				SPI_PUSHR_CONT;
+static int dspi_eoq_write(struct fsl_dspi *dspi)
+{
+	int tx_count = 0;
+	int tx_word;
+	u32 dspi_pushr = 0;
+	int first = 1;
 
-			dspi->len--;
+	tx_word = is_double_byte_mode(dspi);
+
+	while (dspi->len && (tx_count < DSPI_FIFO_SIZE)) {
+		/* If we are in word mode, only have a single byte to transfer
+		 * switch to byte mode temporarily.  Will switch back at the
+		 * end of the transfer.
+		 */
+		if (tx_word && (dspi->len == 1)) {
+			dspi->dataflags |= TRAN_STATE_WORD_ODD_NUM;
+			regmap_update_bits(dspi->regmap, SPI_CTAR(dspi->cs),
+					SPI_FRAME_BITS_MASK, SPI_FRAME_BITS(8));
+			tx_word = 0;
 		}
 
+		dspi_pushr = dspi_data_to_pushr(dspi, tx_word);
+
 		if (dspi->len == 0 || tx_count == DSPI_FIFO_SIZE - 1) {
 			/* last transfer in the transfer */
 			dspi_pushr |= SPI_PUSHR_EOQ;
@@ -291,40 +313,55 @@ static int dspi_transfer_write(struct fsl_dspi *dspi)
 	return tx_count * (tx_word + 1);
 }
 
-static int dspi_transfer_read(struct fsl_dspi *dspi)
+static int dspi_eoq_read(struct fsl_dspi *dspi)
 {
 	int rx_count = 0;
 	int rx_word = is_double_byte_mode(dspi);
-	u16 d;
 
 	while ((dspi->rx < dspi->rx_end)
 			&& (rx_count < DSPI_FIFO_SIZE)) {
-		if (rx_word) {
-			unsigned int val;
+		if (rx_word && (dspi->rx_end - dspi->rx) == 1)
+			rx_word = 0;
 
-			if ((dspi->rx_end - dspi->rx) == 1)
-				break;
+		dspi_data_from_popr(dspi, rx_word);
+		rx_count++;
+	}
 
-			regmap_read(dspi->regmap, SPI_POPR, &val);
-			d = SPI_POPR_RXDATA(val);
+	return rx_count;
+}
 
-			if (!(dspi->dataflags & TRAN_STATE_RX_VOID))
-				*(u16 *)dspi->rx = d;
-			dspi->rx += 2;
+static int dspi_tcfq_write(struct fsl_dspi *dspi)
+{
+	int tx_word;
+	u32 dspi_pushr = 0;
 
-		} else {
-			unsigned int val;
+	tx_word = is_double_byte_mode(dspi);
 
-			regmap_read(dspi->regmap, SPI_POPR, &val);
-			d = SPI_POPR_RXDATA(val);
-			if (!(dspi->dataflags & TRAN_STATE_RX_VOID))
-				*(u8 *)dspi->rx = d;
-			dspi->rx++;
-		}
-		rx_count++;
+	if (tx_word && (dspi->len == 1)) {
+		dspi->dataflags |= TRAN_STATE_WORD_ODD_NUM;
+		regmap_update_bits(dspi->regmap, SPI_CTAR(dspi->cs),
+				SPI_FRAME_BITS_MASK, SPI_FRAME_BITS(8));
+		tx_word = 0;
 	}
 
-	return rx_count;
+	dspi_pushr = dspi_data_to_pushr(dspi, tx_word);
+
+	if ((dspi->cs_change) && (!dspi->len))
+		dspi_pushr &= ~SPI_PUSHR_CONT;
+
+	regmap_write(dspi->regmap, SPI_PUSHR, dspi_pushr);
+
+	return tx_word + 1;
+}
+
+static void dspi_tcfq_read(struct fsl_dspi *dspi)
+{
+	int rx_word = is_double_byte_mode(dspi);
+
+	if (rx_word && (dspi->rx_end - dspi->rx) == 1)
+		rx_word = 0;
+
+	dspi_data_from_popr(dspi, rx_word);
 }
 
 static int dspi_transfer_one_message(struct spi_master *master,
@@ -334,6 +371,7 @@ static int dspi_transfer_one_message(struct spi_master *master,
 	struct spi_device *spi = message->spi;
 	struct spi_transfer *transfer;
 	int status = 0;
+
 	message->actual_length = 0;
 
 	list_for_each_entry(transfer, &message->transfers, transfer_list) {
@@ -370,8 +408,13 @@ static int dspi_transfer_one_message(struct spi_master *master,
 			regmap_write(dspi->regmap, SPI_CTAR(dspi->cs),
 					dspi->cur_chip->ctar_val);
 
-		regmap_write(dspi->regmap, SPI_RSER, SPI_RSER_EOQFE);
-		message->actual_length += dspi_transfer_write(dspi);
+		if (dspi->devtype_data->trans_mode == DSPI_EOQ_MODE) {
+			regmap_write(dspi->regmap, SPI_RSER, SPI_RSER_EOQFE);
+			message->actual_length += dspi_eoq_write(dspi);
+		} else if (dspi->devtype_data->trans_mode == DSPI_TCFQ_MODE) {
+			regmap_write(dspi->regmap, SPI_RSER, SPI_RSER_TCFQE);
+			message->actual_length += dspi_tcfq_write(dspi);
+		}
 
 		if (wait_event_interruptible(dspi->waitq, dspi->waitflags))
 			dev_err(&dspi->pdev->dev, "wait transfer complete fail!\n");
@@ -460,27 +503,39 @@ static void dspi_cleanup(struct spi_device *spi)
 static irqreturn_t dspi_interrupt(int irq, void *dev_id)
 {
 	struct fsl_dspi *dspi = (struct fsl_dspi *)dev_id;
-
 	struct spi_message *msg = dspi->cur_msg;
 
-	regmap_write(dspi->regmap, SPI_SR, SPI_SR_EOQF);
-	dspi_transfer_read(dspi);
+	if (dspi->devtype_data->trans_mode == DSPI_EOQ_MODE) {
+		regmap_write(dspi->regmap, SPI_SR, SPI_SR_EOQF);
+		dspi_eoq_read(dspi);
+	} else if (dspi->devtype_data->trans_mode == DSPI_TCFQ_MODE) {
+		regmap_write(dspi->regmap, SPI_SR, SPI_SR_TCFQF);
+		dspi_tcfq_read(dspi);
+	}
 
 	if (!dspi->len) {
-		if (dspi->dataflags & TRAN_STATE_WORD_ODD_NUM)
+		if (dspi->dataflags & TRAN_STATE_WORD_ODD_NUM) {
 			regmap_update_bits(dspi->regmap, SPI_CTAR(dspi->cs),
 			SPI_FRAME_BITS_MASK, SPI_FRAME_BITS(16));
+			dspi->dataflags &= ~TRAN_STATE_WORD_ODD_NUM;
+		}
 
 		dspi->waitflags = 1;
 		wake_up_interruptible(&dspi->waitq);
-	} else
-		msg->actual_length += dspi_transfer_write(dspi);
-
+	} else {
+		if (dspi->devtype_data->trans_mode == DSPI_EOQ_MODE)
+			msg->actual_length += dspi_eoq_write(dspi);
+		else if (dspi->devtype_data->trans_mode == DSPI_TCFQ_MODE)
+			msg->actual_length += dspi_tcfq_write(dspi);
+	}
 	return IRQ_HANDLED;
 }
 
 static const struct of_device_id fsl_dspi_dt_ids[] = {
-	{ .compatible = "fsl,vf610-dspi", .data = NULL, },
+	{ .compatible = "fsl,vf610-dspi", .data = (void *)&vf610_data, },
+	{ .compatible = "fsl,ls1021a-v1.0-dspi",
+		.data = (void *)&ls1021a_v1_data, },
+	{ .compatible = "fsl,ls2085a-dspi", .data = (void *)&ls2085a_data, },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, fsl_dspi_dt_ids);
@@ -526,6 +581,8 @@ static int dspi_probe(struct platform_device *pdev)
 	struct resource *res;
 	void __iomem *base;
 	int ret = 0, cs_num, bus_num;
+	const struct of_device_id *of_id =
+			of_match_device(fsl_dspi_dt_ids, &pdev->dev);
 
 	master = spi_alloc_master(&pdev->dev, sizeof(struct fsl_dspi));
 	if (!master)
@@ -559,6 +616,13 @@ static int dspi_probe(struct platform_device *pdev)
 	}
 	master->bus_num = bus_num;
 
+	dspi->devtype_data = (struct fsl_dspi_devtype_data *)of_id->data;
+	if (!dspi->devtype_data) {
+		dev_err(&pdev->dev, "can't get devtype_data\n");
+		ret = -EFAULT;
+		goto out_master_put;
+	}
+
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(base)) {
-- 
2.1.0.27.g96db324

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Re: [PATCH v3] spi: spi-fsl-dspi: Enable TCF interrupt mode support

[Mark Brown]

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On Mon, May 25, 2015 at 06:07:49PM +0800, Haikun Wang wrote:

> +		if (dspi->devtype_data->trans_mode == DSPI_EOQ_MODE) {
> +			regmap_write(dspi->regmap, SPI_RSER, SPI_RSER_EOQFE);
> +			message->actual_length += dspi_eoq_write(dspi);
> +		} else if (dspi->devtype_data->trans_mode == DSPI_TCFQ_MODE) {
> +			regmap_write(dspi->regmap, SPI_RSER, SPI_RSER_TCFQE);
> +			message->actual_length += dspi_tcfq_write(dspi);
> +		}

Please use switch statements to select between variants (this is more
idiomatic and makes it easier to add any new variants) both here and in
the other place where you do this.  It'd also be better to handle the
default case - what happens if we forgot a mode here?  I'd expect at
least an error message.

Otherwise this looks good.

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