Initial import

1 files changed, 643 insertions, 0 deletions

diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
new file mode 100644
index 000000000..5fe54cda3
--- /dev/null
+++ b/drivers/spi/spi-fsl-dspi.c
@@ -0,0 +1,643 @@
+/*
+ * drivers/spi/spi-fsl-dspi.c
+ *
+ * Copyright 2013 Freescale Semiconductor, Inc.
+ *
+ * Freescale DSPI driver
+ * This file contains a driver for the Freescale DSPI
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#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>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/sched.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+#include <linux/time.h>
+
+#define DRIVER_NAME "fsl-dspi"
+
+#define TRAN_STATE_RX_VOID		0x01
+#define TRAN_STATE_TX_VOID		0x02
+#define TRAN_STATE_WORD_ODD_NUM	0x04
+
+#define DSPI_FIFO_SIZE			4
+
+#define SPI_MCR		0x00
+#define SPI_MCR_MASTER		(1 << 31)
+#define SPI_MCR_PCSIS		(0x3F << 16)
+#define SPI_MCR_CLR_TXF	(1 << 11)
+#define SPI_MCR_CLR_RXF	(1 << 10)
+
+#define SPI_TCR			0x08
+
+#define SPI_CTAR(x)		(0x0c + (((x) & 0x3) * 4))
+#define SPI_CTAR_FMSZ(x)	(((x) & 0x0000000f) << 27)
+#define SPI_CTAR_CPOL(x)	((x) << 26)
+#define SPI_CTAR_CPHA(x)	((x) << 25)
+#define SPI_CTAR_LSBFE(x)	((x) << 24)
+#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)
+#define SPI_CTAR_CSSCK(x)	(((x) & 0x0000000f) << 12)
+#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
+
+#define SPI_SR			0x2c
+#define SPI_SR_EOQF		0x10000000
+
+#define SPI_RSER		0x30
+#define SPI_RSER_EOQFE		0x10000000
+
+#define SPI_PUSHR		0x34
+#define SPI_PUSHR_CONT		(1 << 31)
+#define SPI_PUSHR_CTAS(x)	(((x) & 0x00000003) << 28)
+#define SPI_PUSHR_EOQ		(1 << 27)
+#define SPI_PUSHR_CTCNT	(1 << 26)
+#define SPI_PUSHR_PCS(x)	(((1 << x) & 0x0000003f) << 16)
+#define SPI_PUSHR_TXDATA(x)	((x) & 0x0000ffff)
+
+#define SPI_PUSHR_SLAVE	0x34
+
+#define SPI_POPR		0x38
+#define SPI_POPR_RXDATA(x)	((x) & 0x0000ffff)
+
+#define SPI_TXFR0		0x3c
+#define SPI_TXFR1		0x40
+#define SPI_TXFR2		0x44
+#define SPI_TXFR3		0x48
+#define SPI_RXFR0		0x7c
+#define SPI_RXFR1		0x80
+#define SPI_RXFR2		0x84
+#define SPI_RXFR3		0x88
+
+#define SPI_FRAME_BITS(bits)	SPI_CTAR_FMSZ((bits) - 1)
+#define SPI_FRAME_BITS_MASK	SPI_CTAR_FMSZ(0xf)
+#define SPI_FRAME_BITS_16	SPI_CTAR_FMSZ(0xf)
+#define SPI_FRAME_BITS_8	SPI_CTAR_FMSZ(0x7)
+
+#define SPI_CS_INIT		0x01
+#define SPI_CS_ASSERT		0x02
+#define SPI_CS_DROP		0x04
+
+struct chip_data {
+	u32 mcr_val;
+	u32 ctar_val;
+	u16 void_write_data;
+};
+
+struct fsl_dspi {
+	struct spi_master	*master;
+	struct platform_device	*pdev;
+
+	struct regmap		*regmap;
+	int			irq;
+	struct clk		*clk;
+
+	struct spi_transfer	*cur_transfer;
+	struct spi_message	*cur_msg;
+	struct chip_data	*cur_chip;
+	size_t			len;
+	void			*tx;
+	void			*tx_end;
+	void			*rx;
+	void			*rx_end;
+	char			dataflags;
+	u8			cs;
+	u16			void_write_data;
+	u32			cs_change;
+
+	wait_queue_head_t	waitq;
+	u32			waitflags;
+};
+
+static inline int is_double_byte_mode(struct fsl_dspi *dspi)
+{
+	unsigned int val;
+
+	regmap_read(dspi->regmap, SPI_CTAR(dspi->cs), &val);
+
+	return ((val & SPI_FRAME_BITS_MASK) == SPI_FRAME_BITS(8)) ? 0 : 1;
+}
+
+static void hz_to_spi_baud(char *pbr, char *br, int speed_hz,
+		unsigned long clkrate)
+{
+	/* Valid baud rate pre-scaler values */
+	int pbr_tbl[4] = {2, 3, 5, 7};
+	int brs[16] = {	2,	4,	6,	8,
+		16,	32,	64,	128,
+		256,	512,	1024,	2048,
+		4096,	8192,	16384,	32768 };
+	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;
+			}
+		}
+
+	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;
+	}
+}
+
+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;
+			}
+		}
+
+	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)
+{
+	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 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;
+	}
+
+	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--;
+		}
+
+		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;
+
+		if (first) {
+			first = 0;
+			dspi_pushr |= SPI_PUSHR_CTCNT; /* clear counter */
+		}
+
+		regmap_write(dspi->regmap, SPI_PUSHR, dspi_pushr);
+
+		tx_count++;
+	}
+
+	return tx_count * (tx_word + 1);
+}
+
+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) {
+			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++;
+		}
+		rx_count++;
+	}
+
+	return rx_count;
+}
+
+static int dspi_transfer_one_message(struct spi_master *master,
+		struct spi_message *message)
+{
+	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);
+
+		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 (transfer->delay_usecs)
+			udelay(transfer->delay_usecs);
+	}
+
+	message->status = status;
+	spi_finalize_current_message(master);
+
+	return status;
+}
+
+static int dspi_setup(struct spi_device *spi)
+{
+	struct chip_data *chip;
+	struct fsl_dspi *dspi = spi_master_get_devdata(spi->master);
+	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);
+	if (chip == NULL) {
+		chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
+		if (!chip)
+			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;
+
+	chip->void_write_data = 0;
+
+	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);
+
+	spi_set_ctldata(spi, chip);
+
+	return 0;
+}
+
+static void dspi_cleanup(struct spi_device *spi)
+{
+	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);
+
+	kfree(chip);
+}
+
+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->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));
+
+		dspi->waitflags = 1;
+		wake_up_interruptible(&dspi->waitq);
+	} else
+		msg->actual_length += dspi_transfer_write(dspi);
+
+	return IRQ_HANDLED;
+}
+
+static const struct of_device_id fsl_dspi_dt_ids[] = {
+	{ .compatible = "fsl,vf610-dspi", .data = NULL, },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, fsl_dspi_dt_ids);
+
+#ifdef CONFIG_PM_SLEEP
+static int dspi_suspend(struct device *dev)
+{
+	struct spi_master *master = dev_get_drvdata(dev);
+	struct fsl_dspi *dspi = spi_master_get_devdata(master);
+
+	spi_master_suspend(master);
+	clk_disable_unprepare(dspi->clk);
+
+	return 0;
+}
+
+static int dspi_resume(struct device *dev)
+{
+	struct spi_master *master = dev_get_drvdata(dev);
+	struct fsl_dspi *dspi = spi_master_get_devdata(master);
+
+	clk_prepare_enable(dspi->clk);
+	spi_master_resume(master);
+
+	return 0;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+static SIMPLE_DEV_PM_OPS(dspi_pm, dspi_suspend, dspi_resume);
+
+static const struct regmap_config dspi_regmap_config = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.max_register = 0x88,
+};
+
+static int dspi_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct spi_master *master;
+	struct fsl_dspi *dspi;
+	struct resource *res;
+	void __iomem *base;
+	int ret = 0, cs_num, bus_num;
+
+	master = spi_alloc_master(&pdev->dev, sizeof(struct fsl_dspi));
+	if (!master)
+		return -ENOMEM;
+
+	dspi = spi_master_get_devdata(master);
+	dspi->pdev = pdev;
+	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;
+	master->bits_per_word_mask = SPI_BPW_MASK(4) | SPI_BPW_MASK(8) |
+					SPI_BPW_MASK(16);
+
+	ret = of_property_read_u32(np, "spi-num-chipselects", &cs_num);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "can't get spi-num-chipselects\n");
+		goto out_master_put;
+	}
+	master->num_chipselect = cs_num;
+
+	ret = of_property_read_u32(np, "bus-num", &bus_num);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "can't get bus-num\n");
+		goto out_master_put;
+	}
+	master->bus_num = bus_num;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(base)) {
+		ret = PTR_ERR(base);
+		goto out_master_put;
+	}
+
+	dspi->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "dspi", base,
+						&dspi_regmap_config);
+	if (IS_ERR(dspi->regmap)) {
+		dev_err(&pdev->dev, "failed to init regmap: %ld\n",
+				PTR_ERR(dspi->regmap));
+		return PTR_ERR(dspi->regmap);
+	}
+
+	dspi->irq = platform_get_irq(pdev, 0);
+	if (dspi->irq < 0) {
+		dev_err(&pdev->dev, "can't get platform irq\n");
+		ret = dspi->irq;
+		goto out_master_put;
+	}
+
+	ret = devm_request_irq(&pdev->dev, dspi->irq, dspi_interrupt, 0,
+			pdev->name, dspi);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Unable to attach DSPI interrupt\n");
+		goto out_master_put;
+	}
+
+	dspi->clk = devm_clk_get(&pdev->dev, "dspi");
+	if (IS_ERR(dspi->clk)) {
+		ret = PTR_ERR(dspi->clk);
+		dev_err(&pdev->dev, "unable to get clock\n");
+		goto out_master_put;
+	}
+	clk_prepare_enable(dspi->clk);
+
+	init_waitqueue_head(&dspi->waitq);
+	platform_set_drvdata(pdev, master);
+
+	ret = spi_register_master(master);
+	if (ret != 0) {
+		dev_err(&pdev->dev, "Problem registering DSPI master\n");
+		goto out_clk_put;
+	}
+
+	return ret;
+
+out_clk_put:
+	clk_disable_unprepare(dspi->clk);
+out_master_put:
+	spi_master_put(master);
+
+	return ret;
+}
+
+static int dspi_remove(struct platform_device *pdev)
+{
+	struct spi_master *master = platform_get_drvdata(pdev);
+	struct fsl_dspi *dspi = spi_master_get_devdata(master);
+
+	/* Disconnect from the SPI framework */
+	clk_disable_unprepare(dspi->clk);
+	spi_unregister_master(dspi->master);
+	spi_master_put(dspi->master);
+
+	return 0;
+}
+
+static struct platform_driver fsl_dspi_driver = {
+	.driver.name    = DRIVER_NAME,
+	.driver.of_match_table = fsl_dspi_dt_ids,
+	.driver.owner   = THIS_MODULE,
+	.driver.pm = &dspi_pm,
+	.probe          = dspi_probe,
+	.remove		= dspi_remove,
+};
+module_platform_driver(fsl_dspi_driver);
+
+MODULE_DESCRIPTION("Freescale DSPI Controller Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRIVER_NAME);