spi:fsl-dspi:add dspi tcfq mode transfer support

TCFQ is interrupt of Transfer Complete Flag in DSPI module.
EOQ is interrupt of End of Queue Flag in DSPI module.
For adopting of different platform, either of them is a way of DSPI
transfer data. This patch add TCF support for DSPI module  in other platform.

The software will be changed in two transfer methods as followwing:
		 EOQ			TCFQ
transfer data: dspi_eoq_write	  dspi_tcfq_write
receive data:  dspi_eoq_read	  dspi_tcfq_read

Using which method will decided by paltform soc dtsi file.

Remove bitbang:
Add tcf funtions, DSPI module need get cs change information in a spi transfer.
According cs change, DSPI will give last data the right flag. Bitbang provide
cs change behind the last data in a transfer. So DSPI can not deal the last data in
every transfer properly, so remove the bitbang in the driver.

Merge duplicate code:
	dspi_data_from_popr
	dspi_data_to_pushr

Remove clk reference in regmap I/O:
Set the clk parament is NULL in devm_regmap_init_mmio_clk, it will avoid clk handle
in every register read/write, and advance tranferring efficiency.

Signed-off-by: Chao Fu <b44548@freescale.com>

The upstream status of this patch can be found at: https://patchwork.kernel.org/patch/4974181

Change-Id: I0ed6c1598c111e74b5e53c248e00dec2398fa900
Reviewed-on: http://git.am.freescale.net:8181/20096
Tested-by: Review Code-CDREVIEW <CDREVIEW@freescale.com>
Reviewed-by: Li Xiubo <Li.Xiubo@freescale.com>
Reviewed-by: Zhengxiong Jin <Jason.Jin@freescale.com>

2 files changed, 198 insertions, 124 deletions

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 21bf181..c17c349 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -263,7 +263,6 @@ config SPI_FSL_SPI
 
 config SPI_FSL_DSPI
 	tristate "Freescale DSPI controller"
-	select SPI_BITBANG
 	select REGMAP_MMIO
 	depends on SOC_VF610 || COMPILE_TEST
 	help
diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
index ebc4d1f..ec0ad01 100644
--- a/drivers/spi/spi-fsl-dspi.c
+++ b/drivers/spi/spi-fsl-dspi.c
@@ -63,9 +63,11 @@
 #define SPI_CTAR0_SLAVE	0x0c
 
 #define SPI_SR			0x2c
+#define SPI_SR_TCFQF		0x80000000
 #define SPI_SR_EOQF		0x10000000
 
 #define SPI_RSER		0x30
+#define SPI_RSER_TCFQE		0x80000000
 #define SPI_RSER_EOQFE		0x10000000
 
 #define SPI_PUSHR		0x34
@@ -105,8 +107,14 @@ struct chip_data {
 	u16 void_write_data;
 };
 
+enum dspi_trans_mode {
+	DSPI_EOQ_MODE = 0,
+	DSPI_TCFQ_MODE,
+	DSPI_DMA_MODE, /*TODO*/
+};
+
 struct fsl_dspi {
-	struct spi_bitbang	bitbang;
+	struct spi_master	*master;
 	struct platform_device	*pdev;
 
 	struct regmap		*regmap;
@@ -114,6 +122,7 @@ struct fsl_dspi {
 	struct clk		*clk;
 
 	struct spi_transfer	*cur_transfer;
+	struct spi_message	*cur_msg;
 	struct chip_data	*cur_chip;
 	size_t			len;
 	void			*tx;
@@ -123,6 +132,8 @@ struct fsl_dspi {
 	char			dataflags;
 	u8			cs;
 	u16			void_write_data;
+	u32			cs_change;
+	enum dspi_trans_mode	trans_mode;
 
 	wait_queue_head_t	waitq;
 	u32			waitflags;
@@ -165,12 +176,68 @@ static void hz_to_spi_baud(char *pbr, char *br, int speed_hz,
 	*br =  ARRAY_SIZE(brs) - 1;
 }
 
-static int dspi_transfer_write(struct fsl_dspi *dspi)
+static u32 dspi_data_to_pushr(struct fsl_dspi *dspi, int tx_word)
+{
+	u16 d16;
+	u8 d8;
+
+	if (tx_word) {
+		if (!(dspi->dataflags & TRAN_STATE_TX_VOID)) {
+			d16 = *(u16 *)dspi->tx;
+			dspi->tx += 2;
+		} else {
+			d16 = dspi->void_write_data;
+		}
+
+		dspi->len -= 2;
+
+		return	SPI_PUSHR_TXDATA(d16) |
+			SPI_PUSHR_PCS(dspi->cs) |
+			SPI_PUSHR_CTAS(dspi->cs) |
+			SPI_PUSHR_CONT;
+	} else {
+		if (!(dspi->dataflags & TRAN_STATE_TX_VOID)) {
+
+			d8 = *(u8 *)dspi->tx;
+			dspi->tx++;
+		} else {
+			d8 = (u8)dspi->void_write_data;
+		}
+
+		dspi->len--;
+
+		return SPI_PUSHR_TXDATA(d8) |
+			SPI_PUSHR_PCS(dspi->cs) |
+			SPI_PUSHR_CTAS(dspi->cs) |
+			SPI_PUSHR_CONT;
+	}
+}
+
+static void dspi_data_from_popr(struct fsl_dspi *dspi, int rx_word)
+{
+	u16 d;
+	unsigned int val;
+
+	if (rx_word) {
+		regmap_read(dspi->regmap, SPI_POPR, &val);
+		d = SPI_POPR_RXDATA(val);
+
+		if (!(dspi->dataflags & TRAN_STATE_RX_VOID))
+			*(u16 *)dspi->rx = d;
+		dspi->rx += 2;
+	} else {
+		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++;
+	}
+}
+
+static int dspi_eoq_write(struct fsl_dspi *dspi)
 {
 	int tx_count = 0;
 	int tx_word;
-	u16 d16;
-	u8  d8;
 	u32 dspi_pushr = 0;
 	int first = 1;
 
@@ -188,43 +255,13 @@ static int dspi_transfer_write(struct fsl_dspi *dspi)
 	}
 
 	while (dspi->len && (tx_count < DSPI_FIFO_SIZE)) {
-		if (tx_word) {
-			if (dspi->len == 1)
-				break;
-
-			if (!(dspi->dataflags & TRAN_STATE_TX_VOID)) {
-				d16 = *(u16 *)dspi->tx;
-				dspi->tx += 2;
-			} else {
-				d16 = dspi->void_write_data;
-			}
-
-			dspi_pushr = SPI_PUSHR_TXDATA(d16) |
-				SPI_PUSHR_PCS(dspi->cs) |
-				SPI_PUSHR_CTAS(dspi->cs) |
-				SPI_PUSHR_CONT;
-
-			dspi->len -= 2;
-		} else {
-			if (!(dspi->dataflags & TRAN_STATE_TX_VOID)) {
-
-				d8 = *(u8 *)dspi->tx;
-				dspi->tx++;
-			} else {
-				d8 = (u8)dspi->void_write_data;
-			}
-
-			dspi_pushr = SPI_PUSHR_TXDATA(d8) |
-				SPI_PUSHR_PCS(dspi->cs) |
-				SPI_PUSHR_CTAS(dspi->cs) |
-				SPI_PUSHR_CONT;
-
-			dspi->len--;
-		}
+		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;
+			if ((dspi->cs_change) && (!dspi->len))
+				dspi_pushr &= ~SPI_PUSHR_CONT;
 		} else if (tx_word && (dspi->len == 1))
 			dspi_pushr |= SPI_PUSHR_EOQ;
 
@@ -241,99 +278,119 @@ 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 ((dspi->rx_end - dspi->rx) == 1)
-				break;
-
-			regmap_read(dspi->regmap, SPI_POPR, &val);
-			d = SPI_POPR_RXDATA(val);
-
-			if (!(dspi->dataflags & TRAN_STATE_RX_VOID))
-				*(u16 *)dspi->rx = d;
-			dspi->rx += 2;
-
-		} else {
-			unsigned int val;
-
-			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++;
-		}
+		dspi_data_from_popr(dspi, rx_word);
 		rx_count++;
 	}
 
 	return rx_count;
 }
 
-static int dspi_txrx_transfer(struct spi_device *spi, struct spi_transfer *t)
+static int dspi_tcfq_write(struct fsl_dspi *dspi)
 {
-	struct fsl_dspi *dspi = spi_master_get_devdata(spi->master);
-	dspi->cur_transfer = t;
-	dspi->cur_chip = spi_get_ctldata(spi);
-	dspi->cs = spi->chip_select;
-	dspi->void_write_data = dspi->cur_chip->void_write_data;
+	int tx_word;
+	u32 dspi_pushr = 0;
 
-	dspi->dataflags = 0;
-	dspi->tx = (void *)t->tx_buf;
-	dspi->tx_end = dspi->tx + t->len;
-	dspi->rx = t->rx_buf;
-	dspi->rx_end = dspi->rx + t->len;
-	dspi->len = t->len;
+	tx_word = is_double_byte_mode(dspi);
 
-	if (!dspi->rx)
-		dspi->dataflags |= TRAN_STATE_RX_VOID;
+	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;
+	}
 
-	if (!dspi->tx)
-		dspi->dataflags |= TRAN_STATE_TX_VOID;
+	dspi_pushr = dspi_data_to_pushr(dspi, tx_word);
 
-	regmap_write(dspi->regmap, SPI_MCR, dspi->cur_chip->mcr_val);
-	regmap_write(dspi->regmap, SPI_CTAR(dspi->cs), dspi->cur_chip->ctar_val);
-	regmap_write(dspi->regmap, SPI_RSER, SPI_RSER_EOQFE);
+	if ((dspi->cs_change) && (!dspi->len))
+		dspi_pushr &= ~SPI_PUSHR_CONT;
 
-	if (t->speed_hz)
-		regmap_write(dspi->regmap, SPI_CTAR(dspi->cs),
-				dspi->cur_chip->ctar_val);
+	regmap_write(dspi->regmap, SPI_PUSHR, dspi_pushr);
 
-	dspi_transfer_write(dspi);
+	return tx_word + 1;
+}
 
-	if (wait_event_interruptible(dspi->waitq, dspi->waitflags))
-		dev_err(&dspi->pdev->dev, "wait transfer complete fail!\n");
-	dspi->waitflags = 0;
+static void dspi_tcfq_read(struct fsl_dspi *dspi)
+{
+	int rx_word = is_double_byte_mode(dspi);
 
-	return t->len - dspi->len;
+	dspi_data_from_popr(dspi, rx_word);
 }
 
-static void dspi_chipselect(struct spi_device *spi, int value)
+static int dspi_transfer_one_message(struct spi_master *master,
+		struct spi_message *message)
 {
-	struct fsl_dspi *dspi = spi_master_get_devdata(spi->master);
-	unsigned int pushr;
+	struct fsl_dspi *dspi = spi_master_get_devdata(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) {
+		dspi->cur_transfer = transfer;
+		dspi->cur_msg = message;
+		dspi->cur_chip = spi_get_ctldata(spi);
+		dspi->cs = spi->chip_select;
+		if (dspi->cur_transfer->transfer_list.next
+				== &dspi->cur_msg->transfers)
+			transfer->cs_change = 1;
+		dspi->cs_change = transfer->cs_change;
+		dspi->void_write_data = dspi->cur_chip->void_write_data;
+
+		dspi->dataflags = 0;
+		dspi->tx = (void *)transfer->tx_buf;
+		dspi->tx_end = dspi->tx + transfer->len;
+		dspi->rx = transfer->rx_buf;
+		dspi->rx_end = dspi->rx + transfer->len;
+		dspi->len = transfer->len;
+
+		if (!dspi->rx)
+			dspi->dataflags |= TRAN_STATE_RX_VOID;
+
+		if (!dspi->tx)
+			dspi->dataflags |= TRAN_STATE_TX_VOID;
+
+		regmap_write(dspi->regmap, SPI_MCR, dspi->cur_chip->mcr_val);
+		regmap_update_bits(dspi->regmap, SPI_MCR,
+				SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF,
+				SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF);
+		regmap_write(dspi->regmap, SPI_CTAR(dspi->cs),
+				dspi->cur_chip->ctar_val);
+		if (transfer->speed_hz)
+			regmap_write(dspi->regmap, SPI_CTAR(dspi->cs),
+					dspi->cur_chip->ctar_val);
+
+		if (dspi->trans_mode == DSPI_EOQ_MODE) {
+			regmap_write(dspi->regmap, SPI_RSER, SPI_RSER_EOQFE);
+			message->actual_length += dspi_eoq_write(dspi);
+		} else if (dspi->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");
+		dspi->waitflags = 0;
 
-	regmap_read(dspi->regmap, SPI_PUSHR, &pushr);
+		if (transfer->delay_usecs)
+			udelay(transfer->delay_usecs);
 
-	switch (value) {
-	case BITBANG_CS_ACTIVE:
-		pushr |= SPI_PUSHR_CONT;
-		break;
-	case BITBANG_CS_INACTIVE:
-		pushr &= ~SPI_PUSHR_CONT;
-		break;
 	}
 
-	regmap_write(dspi->regmap, SPI_PUSHR, pushr);
+	message->status = status;
+	spi_finalize_current_message(master);
+
+	return status;
+
 }
 
-static int dspi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
+static int dspi_setup(struct spi_device *spi)
 {
 	struct chip_data *chip;
 	struct fsl_dspi *dspi = spi_master_get_devdata(spi->master);
@@ -343,7 +400,7 @@ static int dspi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
 	chip = spi_get_ctldata(spi);
 	if (chip == NULL) {
 		chip = devm_kzalloc(&spi->dev, sizeof(struct chip_data),
-				    GFP_KERNEL);
+					GFP_KERNEL);
 		if (!chip)
 			return -ENOMEM;
 	}
@@ -374,21 +431,28 @@ static int dspi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
 	return 0;
 }
 
-static int dspi_setup(struct spi_device *spi)
+static void dspi_cleanup(struct spi_device *spi)
 {
-	if (!spi->max_speed_hz)
-		return -EINVAL;
+	struct chip_data *chip = spi_get_ctldata((struct spi_device *)spi);
+
+	dev_dbg(&spi->dev, "spi_device %u.%u cleanup\n",
+			spi->master->bus_num, spi->chip_select);
 
-	return dspi_setup_transfer(spi, NULL);
+	kfree(chip);
 }
 
 static irqreturn_t dspi_interrupt(int irq, void *dev_id)
 {
 	struct fsl_dspi *dspi = (struct fsl_dspi *)dev_id;
-
-	regmap_write(dspi->regmap, SPI_SR, SPI_SR_EOQF);
-
-	dspi_transfer_read(dspi);
+	struct spi_message *msg = dspi->cur_msg;
+
+	if (dspi->trans_mode == DSPI_EOQ_MODE) {
+		regmap_write(dspi->regmap, SPI_SR, SPI_SR_EOQF);
+		dspi_eoq_read(dspi);
+	} else if (dspi->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)
@@ -398,9 +462,10 @@ static irqreturn_t dspi_interrupt(int irq, void *dev_id)
 		dspi->waitflags = 1;
 		wake_up_interruptible(&dspi->waitq);
 	} else {
-		dspi_transfer_write(dspi);
-
-		return IRQ_HANDLED;
+		if (dspi->trans_mode == DSPI_EOQ_MODE)
+			msg->actual_length += dspi_eoq_write(dspi);
+		else if (dspi->trans_mode == DSPI_TCFQ_MODE)
+			msg->actual_length += dspi_tcfq_write(dspi);
 	}
 
 	return IRQ_HANDLED;
@@ -460,12 +525,13 @@ static int dspi_probe(struct platform_device *pdev)
 
 	dspi = spi_master_get_devdata(master);
 	dspi->pdev = pdev;
-	dspi->bitbang.master = master;
-	dspi->bitbang.chipselect = dspi_chipselect;
-	dspi->bitbang.setup_transfer = dspi_setup_transfer;
-	dspi->bitbang.txrx_bufs = dspi_txrx_transfer;
-	dspi->bitbang.master->setup = dspi_setup;
-	dspi->bitbang.master->dev.of_node = pdev->dev.of_node;
+	dspi->master = master;
+
+	master->transfer = NULL;
+	master->cleanup = dspi_cleanup;
+	master->setup = dspi_setup;
+	master->transfer_one_message = dspi_transfer_one_message;
+	master->dev.of_node = pdev->dev.of_node;
 
 	master->mode_bits = SPI_CPOL | SPI_CPHA;
 	master->bits_per_word_mask = SPI_BPW_MASK(4) | SPI_BPW_MASK(8) |
@@ -485,6 +551,15 @@ static int dspi_probe(struct platform_device *pdev)
 	}
 	master->bus_num = bus_num;
 
+	if (of_property_read_bool(np, "eoq-mode"))
+		dspi->trans_mode = DSPI_EOQ_MODE;
+	else if (of_property_read_bool(np, "tcfq-mode"))
+		dspi->trans_mode = DSPI_TCFQ_MODE;
+	else {
+		dev_err(&pdev->dev, "can't get dspi transfer mode\n");
+		goto out_master_put;
+	}
+
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(base)) {
@@ -493,7 +568,7 @@ static int dspi_probe(struct platform_device *pdev)
 	}
 
 	dspi_regmap_config.lock_arg = dspi;
-	dspi->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "dspi", base,
+	dspi->regmap = devm_regmap_init_mmio_clk(&pdev->dev, NULL, base,
 						&dspi_regmap_config);
 	if (IS_ERR(dspi->regmap)) {
 		dev_err(&pdev->dev, "failed to init regmap: %ld\n",
@@ -526,7 +601,7 @@ static int dspi_probe(struct platform_device *pdev)
 	init_waitqueue_head(&dspi->waitq);
 	platform_set_drvdata(pdev, master);
 
-	ret = spi_bitbang_start(&dspi->bitbang);
+	ret = spi_register_master(master);
 	if (ret != 0) {
 		dev_err(&pdev->dev, "Problem registering DSPI master\n");
 		goto out_clk_put;
@@ -549,9 +624,9 @@ static int dspi_remove(struct platform_device *pdev)
 	struct fsl_dspi *dspi = spi_master_get_devdata(master);
 
 	/* Disconnect from the SPI framework */
-	spi_bitbang_stop(&dspi->bitbang);
 	clk_disable_unprepare(dspi->clk);
-	spi_master_put(dspi->bitbang.master);
+	spi_unregister_master(dspi->master);
+	spi_master_put(dspi->master);
 
 	return 0;
 }