1 files changed, 159 insertions, 95 deletions

diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
index 9b80d54d4ddb..5fe54cda309f 100644
--- a/drivers/spi/spi-fsl-dspi.c
+++ b/drivers/spi/spi-fsl-dspi.c
@@ -20,6 +20,7 @@
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
+#include <linux/math64.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
@@ -29,6 +30,7 @@
 #include <linux/sched.h>
 #include <linux/spi/spi.h>
 #include <linux/spi/spi_bitbang.h>
+#include <linux/time.h>
 
 #define DRIVER_NAME "fsl-dspi"
 
@@ -51,7 +53,7 @@
 #define SPI_CTAR_CPOL(x)	((x) << 26)
 #define SPI_CTAR_CPHA(x)	((x) << 25)
 #define SPI_CTAR_LSBFE(x)	((x) << 24)
-#define SPI_CTAR_PCSSCR(x)	(((x) & 0x00000003) << 22)
+#define SPI_CTAR_PCSSCK(x)	(((x) & 0x00000003) << 22)
 #define SPI_CTAR_PASC(x)	(((x) & 0x00000003) << 20)
 #define SPI_CTAR_PDT(x)	(((x) & 0x00000003) << 18)
 #define SPI_CTAR_PBR(x)	(((x) & 0x00000003) << 16)
@@ -59,6 +61,7 @@
 #define SPI_CTAR_ASC(x)	(((x) & 0x0000000f) << 8)
 #define SPI_CTAR_DT(x)		(((x) & 0x0000000f) << 4)
 #define SPI_CTAR_BR(x)		((x) & 0x0000000f)
+#define SPI_CTAR_SCALE_BITS	0xf
 
 #define SPI_CTAR0_SLAVE	0x0c
 
@@ -106,7 +109,7 @@ struct chip_data {
 };
 
 struct fsl_dspi {
-	struct spi_bitbang	bitbang;
+	struct spi_master	*master;
 	struct platform_device	*pdev;
 
 	struct regmap		*regmap;
@@ -114,6 +117,7 @@ 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 +127,7 @@ struct fsl_dspi {
 	char			dataflags;
 	u8			cs;
 	u16			void_write_data;
+	u32			cs_change;
 
 	wait_queue_head_t	waitq;
 	u32			waitflags;
@@ -146,23 +151,66 @@ static void hz_to_spi_baud(char *pbr, char *br, int speed_hz,
 		16,	32,	64,	128,
 		256,	512,	1024,	2048,
 		4096,	8192,	16384,	32768 };
-	int temp, i = 0, j = 0;
+	int scale_needed, scale, minscale = INT_MAX;
+	int i, j;
+
+	scale_needed = clkrate / speed_hz;
+	if (clkrate % speed_hz)
+		scale_needed++;
+
+	for (i = 0; i < ARRAY_SIZE(brs); i++)
+		for (j = 0; j < ARRAY_SIZE(pbr_tbl); j++) {
+			scale = brs[i] * pbr_tbl[j];
+			if (scale >= scale_needed) {
+				if (scale < minscale) {
+					minscale = scale;
+					*br = i;
+					*pbr = j;
+				}
+				break;
+			}
+		}
 
-	temp = clkrate / 2 / speed_hz;
+	if (minscale == INT_MAX) {
+		pr_warn("Can not find valid baud rate,speed_hz is %d,clkrate is %ld, we use the max prescaler value.\n",
+			speed_hz, clkrate);
+		*pbr = ARRAY_SIZE(pbr_tbl) - 1;
+		*br =  ARRAY_SIZE(brs) - 1;
+	}
+}
 
-	for (i = 0; i < ARRAY_SIZE(pbr_tbl); i++)
-		for (j = 0; j < ARRAY_SIZE(brs); j++) {
-			if (pbr_tbl[i] * brs[j] >= temp) {
-				*pbr = i;
-				*br = j;
-				return;
+static void ns_delay_scale(char *psc, char *sc, int delay_ns,
+		unsigned long clkrate)
+{
+	int pscale_tbl[4] = {1, 3, 5, 7};
+	int scale_needed, scale, minscale = INT_MAX;
+	int i, j;
+	u32 remainder;
+
+	scale_needed = div_u64_rem((u64)delay_ns * clkrate, NSEC_PER_SEC,
+			&remainder);
+	if (remainder)
+		scale_needed++;
+
+	for (i = 0; i < ARRAY_SIZE(pscale_tbl); i++)
+		for (j = 0; j <= SPI_CTAR_SCALE_BITS; j++) {
+			scale = pscale_tbl[i] * (2 << j);
+			if (scale >= scale_needed) {
+				if (scale < minscale) {
+					minscale = scale;
+					*psc = i;
+					*sc = j;
+				}
+				break;
 			}
 		}
 
-	pr_warn("Can not find valid baud rate,speed_hz is %d,clkrate is %ld\
-		,we use the max prescaler value.\n", speed_hz, clkrate);
-	*pbr = ARRAY_SIZE(pbr_tbl) - 1;
-	*br =  ARRAY_SIZE(brs) - 1;
+	if (minscale == INT_MAX) {
+		pr_warn("Cannot find correct scale values for %dns delay at clkrate %ld, using max prescaler value",
+			delay_ns, clkrate);
+		*psc = ARRAY_SIZE(pscale_tbl) - 1;
+		*sc = SPI_CTAR_SCALE_BITS;
+	}
 }
 
 static int dspi_transfer_write(struct fsl_dspi *dspi)
@@ -225,6 +273,8 @@ static int dspi_transfer_write(struct fsl_dspi *dspi)
 		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;
 
@@ -246,6 +296,7 @@ static int dspi_transfer_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) {
@@ -276,68 +327,81 @@ static int dspi_transfer_read(struct fsl_dspi *dspi)
 	return rx_count;
 }
 
-static int dspi_txrx_transfer(struct spi_device *spi, struct spi_transfer *t)
+static int dspi_transfer_one_message(struct spi_master *master,
+		struct spi_message *message)
 {
-	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;
-
-	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;
-
-	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_write(dspi->regmap, SPI_CTAR(dspi->cs), dspi->cur_chip->ctar_val);
-	regmap_write(dspi->regmap, SPI_RSER, SPI_RSER_EOQFE);
-
-	if (t->speed_hz)
+	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);
 
-	dspi_transfer_write(dspi);
+		regmap_write(dspi->regmap, SPI_RSER, SPI_RSER_EOQFE);
+		message->actual_length += dspi_transfer_write(dspi);
 
-	if (wait_event_interruptible(dspi->waitq, dspi->waitflags))
-		dev_err(&dspi->pdev->dev, "wait transfer complete fail!\n");
-	dspi->waitflags = 0;
+		if (wait_event_interruptible(dspi->waitq, dspi->waitflags))
+			dev_err(&dspi->pdev->dev, "wait transfer complete fail!\n");
+		dspi->waitflags = 0;
 
-	return t->len - dspi->len;
-}
-
-static void dspi_chipselect(struct spi_device *spi, int value)
-{
-	struct fsl_dspi *dspi = spi_master_get_devdata(spi->master);
-	unsigned int pushr;
-
-	regmap_read(dspi->regmap, SPI_PUSHR, &pushr);
-
-	switch (value) {
-	case BITBANG_CS_ACTIVE:
-		pushr |= SPI_PUSHR_CONT;
-		break;
-	case BITBANG_CS_INACTIVE:
-		pushr &= ~SPI_PUSHR_CONT;
-		break;
+		if (transfer->delay_usecs)
+			udelay(transfer->delay_usecs);
 	}
 
-	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);
-	unsigned char br = 0, pbr = 0, fmsz = 0;
+	u32 cs_sck_delay = 0, sck_cs_delay = 0;
+	unsigned char br = 0, pbr = 0, pcssck = 0, cssck = 0;
+	unsigned char pasc = 0, asc = 0, fmsz = 0;
+	unsigned long clkrate;
+
+	if ((spi->bits_per_word >= 4) && (spi->bits_per_word <= 16)) {
+		fmsz = spi->bits_per_word - 1;
+	} else {
+		pr_err("Invalid wordsize\n");
+		return -ENODEV;
+	}
 
 	/* Only alloc on first setup */
 	chip = spi_get_ctldata(spi);
@@ -347,24 +411,34 @@ static int dspi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
 			return -ENOMEM;
 	}
 
+	of_property_read_u32(spi->dev.of_node, "fsl,spi-cs-sck-delay",
+			&cs_sck_delay);
+
+	of_property_read_u32(spi->dev.of_node, "fsl,spi-sck-cs-delay",
+			&sck_cs_delay);
+
 	chip->mcr_val = SPI_MCR_MASTER | SPI_MCR_PCSIS |
 		SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF;
-	if ((spi->bits_per_word >= 4) && (spi->bits_per_word <= 16)) {
-		fmsz = spi->bits_per_word - 1;
-	} else {
-		pr_err("Invalid wordsize\n");
-		return -ENODEV;
-	}
 
 	chip->void_write_data = 0;
 
-	hz_to_spi_baud(&pbr, &br,
-			spi->max_speed_hz, clk_get_rate(dspi->clk));
+	clkrate = clk_get_rate(dspi->clk);
+	hz_to_spi_baud(&pbr, &br, spi->max_speed_hz, clkrate);
+
+	/* Set PCS to SCK delay scale values */
+	ns_delay_scale(&pcssck, &cssck, cs_sck_delay, clkrate);
+
+	/* Set After SCK delay scale values */
+	ns_delay_scale(&pasc, &asc, sck_cs_delay, clkrate);
 
 	chip->ctar_val =  SPI_CTAR_FMSZ(fmsz)
 		| SPI_CTAR_CPOL(spi->mode & SPI_CPOL ? 1 : 0)
 		| SPI_CTAR_CPHA(spi->mode & SPI_CPHA ? 1 : 0)
 		| SPI_CTAR_LSBFE(spi->mode & SPI_LSB_FIRST ? 1 : 0)
+		| SPI_CTAR_PCSSCK(pcssck)
+		| SPI_CTAR_CSSCK(cssck)
+		| SPI_CTAR_PASC(pasc)
+		| SPI_CTAR_ASC(asc)
 		| SPI_CTAR_PBR(pbr)
 		| SPI_CTAR_BR(br);
 
@@ -373,14 +447,6 @@ static int dspi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
 	return 0;
 }
 
-static int dspi_setup(struct spi_device *spi)
-{
-	if (!spi->max_speed_hz)
-		return -EINVAL;
-
-	return dspi_setup_transfer(spi, NULL);
-}
-
 static void dspi_cleanup(struct spi_device *spi)
 {
 	struct chip_data *chip = spi_get_ctldata((struct spi_device *)spi);
@@ -395,22 +461,20 @@ 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);
+	struct spi_message *msg = dspi->cur_msg;
 
+	regmap_write(dspi->regmap, SPI_SR, SPI_SR_EOQF);
 	dspi_transfer_read(dspi);
 
 	if (!dspi->len) {
 		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));
+			SPI_FRAME_BITS_MASK, SPI_FRAME_BITS(16));
 
 		dspi->waitflags = 1;
 		wake_up_interruptible(&dspi->waitq);
-	} else {
-		dspi_transfer_write(dspi);
-
-		return IRQ_HANDLED;
-	}
+	} else
+		msg->actual_length += dspi_transfer_write(dspi);
 
 	return IRQ_HANDLED;
 }
@@ -469,12 +533,12 @@ 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->setup = dspi_setup;
+	master->transfer_one_message = dspi_transfer_one_message;
+	master->dev.of_node = pdev->dev.of_node;
 
 	master->cleanup = dspi_cleanup;
 	master->mode_bits = SPI_CPOL | SPI_CPHA;
@@ -535,7 +599,7 @@ 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;
@@ -557,9 +621,9 @@ 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;
 }