[people/ms/u-boot.git] / drivers / spi / tegra20_slink.c

/*
 * NVIDIA Tegra SPI-SLINK controller
 *
 * Copyright (c) 2010-2013 NVIDIA Corporation
 *
 * SPDX-License-Identifier:	GPL-2.0
 */

#include <common.h>
#include <dm.h>
#include <asm/io.h>
#include <asm/arch/clock.h>
#include <asm/arch-tegra/clk_rst.h>
#include <spi.h>
#include <fdtdec.h>
#include "tegra_spi.h"

DECLARE_GLOBAL_DATA_PTR;

/* COMMAND */
#define SLINK_CMD_ENB			BIT(31)
#define SLINK_CMD_GO			BIT(30)
#define SLINK_CMD_M_S			BIT(28)
#define SLINK_CMD_IDLE_SCLK_DRIVE_LOW	(0 << 24)
#define SLINK_CMD_IDLE_SCLK_DRIVE_HIGH	BIT(24)
#define SLINK_CMD_IDLE_SCLK_PULL_LOW	(2 << 24)
#define SLINK_CMD_IDLE_SCLK_PULL_HIGH	(3 << 24)
#define SLINK_CMD_IDLE_SCLK_MASK	(3 << 24)
#define SLINK_CMD_CK_SDA		BIT(21)
#define SLINK_CMD_CS_POL		BIT(13)
#define SLINK_CMD_CS_VAL		BIT(12)
#define SLINK_CMD_CS_SOFT		BIT(11)
#define SLINK_CMD_BIT_LENGTH		BIT(4)
#define SLINK_CMD_BIT_LENGTH_MASK	GENMASK(4, 0)
/* COMMAND2 */
#define SLINK_CMD2_TXEN			BIT(30)
#define SLINK_CMD2_RXEN			BIT(31)
#define SLINK_CMD2_SS_EN		BIT(18)
#define SLINK_CMD2_SS_EN_SHIFT		18
#define SLINK_CMD2_SS_EN_MASK		GENMASK(19, 18)
#define SLINK_CMD2_CS_ACTIVE_BETWEEN	BIT(17)
/* STATUS */
#define SLINK_STAT_BSY			BIT(31)
#define SLINK_STAT_RDY			BIT(30)
#define SLINK_STAT_ERR			BIT(29)
#define SLINK_STAT_RXF_FLUSH		BIT(27)
#define SLINK_STAT_TXF_FLUSH		BIT(26)
#define SLINK_STAT_RXF_OVF		BIT(25)
#define SLINK_STAT_TXF_UNR		BIT(24)
#define SLINK_STAT_RXF_EMPTY		BIT(23)
#define SLINK_STAT_RXF_FULL		BIT(22)
#define SLINK_STAT_TXF_EMPTY		BIT(21)
#define SLINK_STAT_TXF_FULL		BIT(20)
#define SLINK_STAT_TXF_OVF		BIT(19)
#define SLINK_STAT_RXF_UNR		BIT(18)
#define SLINK_STAT_CUR_BLKCNT		BIT(15)
/* STATUS2 */
#define SLINK_STAT2_RXF_FULL_CNT	BIT(16)
#define SLINK_STAT2_TXF_FULL_CNT	BIT(0)

#define SPI_TIMEOUT		1000
#define TEGRA_SPI_MAX_FREQ	52000000

struct spi_regs {
	u32 command;	/* SLINK_COMMAND_0 register  */
	u32 command2;	/* SLINK_COMMAND2_0 reg */
	u32 status;	/* SLINK_STATUS_0 register */
	u32 reserved;	/* Reserved offset 0C */
	u32 mas_data;	/* SLINK_MAS_DATA_0 reg */
	u32 slav_data;	/* SLINK_SLAVE_DATA_0 reg */
	u32 dma_ctl;	/* SLINK_DMA_CTL_0 register */
	u32 status2;	/* SLINK_STATUS2_0 reg */
	u32 rsvd[56];	/* 0x20 to 0xFF reserved */
	u32 tx_fifo;	/* SLINK_TX_FIFO_0 reg off 100h */
	u32 rsvd2[31];	/* 0x104 to 0x17F reserved */
	u32 rx_fifo;	/* SLINK_RX_FIFO_0 reg off 180h */
};

struct tegra30_spi_priv {
	struct spi_regs *regs;
	unsigned int freq;
	unsigned int mode;
	int periph_id;
	int valid;
	int last_transaction_us;
};

struct tegra_spi_slave {
	struct spi_slave slave;
	struct tegra30_spi_priv *ctrl;
};

static int tegra30_spi_ofdata_to_platdata(struct udevice *bus)
{
	struct tegra_spi_platdata *plat = bus->platdata;
	const void *blob = gd->fdt_blob;
	int node = dev_of_offset(bus);

	plat->base = devfdt_get_addr(bus);
	plat->periph_id = clock_decode_periph_id(bus);

	if (plat->periph_id == PERIPH_ID_NONE) {
		debug("%s: could not decode periph id %d\n", __func__,
		      plat->periph_id);
		return -FDT_ERR_NOTFOUND;
	}

	/* Use 500KHz as a suitable default */
	plat->frequency = fdtdec_get_int(blob, node, "spi-max-frequency",
					500000);
	plat->deactivate_delay_us = fdtdec_get_int(blob, node,
					"spi-deactivate-delay", 0);
	debug("%s: base=%#08lx, periph_id=%d, max-frequency=%d, deactivate_delay=%d\n",
	      __func__, plat->base, plat->periph_id, plat->frequency,
	      plat->deactivate_delay_us);

	return 0;
}

static int tegra30_spi_probe(struct udevice *bus)
{
	struct tegra_spi_platdata *plat = dev_get_platdata(bus);
	struct tegra30_spi_priv *priv = dev_get_priv(bus);

	priv->regs = (struct spi_regs *)plat->base;

	priv->last_transaction_us = timer_get_us();
	priv->freq = plat->frequency;
	priv->periph_id = plat->periph_id;

	/* Change SPI clock to correct frequency, PLLP_OUT0 source */
	clock_start_periph_pll(priv->periph_id, CLOCK_ID_PERIPH,
			       priv->freq);

	return 0;
}

static int tegra30_spi_claim_bus(struct udevice *dev)
{
	struct udevice *bus = dev->parent;
	struct tegra30_spi_priv *priv = dev_get_priv(bus);
	struct spi_regs *regs = priv->regs;
	u32 reg;

	/* Change SPI clock to correct frequency, PLLP_OUT0 source */
	clock_start_periph_pll(priv->periph_id, CLOCK_ID_PERIPH,
			       priv->freq);

	/* Clear stale status here */
	reg = SLINK_STAT_RDY | SLINK_STAT_RXF_FLUSH | SLINK_STAT_TXF_FLUSH | \
		SLINK_STAT_RXF_UNR | SLINK_STAT_TXF_OVF;
	writel(reg, &regs->status);
	debug("%s: STATUS = %08x\n", __func__, readl(&regs->status));

	/* Set master mode and sw controlled CS */
	reg = readl(&regs->command);
	reg |= SLINK_CMD_M_S | SLINK_CMD_CS_SOFT;
	writel(reg, &regs->command);
	debug("%s: COMMAND = %08x\n", __func__, readl(&regs->command));

	return 0;
}

static void spi_cs_activate(struct udevice *dev)
{
	struct udevice *bus = dev->parent;
	struct tegra_spi_platdata *pdata = dev_get_platdata(bus);
	struct tegra30_spi_priv *priv = dev_get_priv(bus);

	/* If it's too soon to do another transaction, wait */
	if (pdata->deactivate_delay_us &&
	    priv->last_transaction_us) {
		ulong delay_us;		/* The delay completed so far */
		delay_us = timer_get_us() - priv->last_transaction_us;
		if (delay_us < pdata->deactivate_delay_us)
			udelay(pdata->deactivate_delay_us - delay_us);
	}

	/* CS is negated on Tegra, so drive a 1 to get a 0 */
	setbits_le32(&priv->regs->command, SLINK_CMD_CS_VAL);
}

static void spi_cs_deactivate(struct udevice *dev)
{
	struct udevice *bus = dev->parent;
	struct tegra_spi_platdata *pdata = dev_get_platdata(bus);
	struct tegra30_spi_priv *priv = dev_get_priv(bus);

	/* CS is negated on Tegra, so drive a 0 to get a 1 */
	clrbits_le32(&priv->regs->command, SLINK_CMD_CS_VAL);

	/* Remember time of this transaction so we can honour the bus delay */
	if (pdata->deactivate_delay_us)
		priv->last_transaction_us = timer_get_us();
}

static int tegra30_spi_xfer(struct udevice *dev, unsigned int bitlen,
			    const void *data_out, void *data_in,
			    unsigned long flags)
{
	struct udevice *bus = dev->parent;
	struct tegra30_spi_priv *priv = dev_get_priv(bus);
	struct spi_regs *regs = priv->regs;
	u32 reg, tmpdout, tmpdin = 0;
	const u8 *dout = data_out;
	u8 *din = data_in;
	int num_bytes;
	int ret;

	debug("%s: slave %u:%u dout %p din %p bitlen %u\n",
	      __func__, bus->seq, spi_chip_select(dev), dout, din, bitlen);
	if (bitlen % 8)
		return -1;
	num_bytes = bitlen / 8;

	ret = 0;

	reg = readl(&regs->status);
	writel(reg, &regs->status);	/* Clear all SPI events via R/W */
	debug("%s entry: STATUS = %08x\n", __func__, reg);

	reg = readl(&regs->status2);
	writel(reg, &regs->status2);	/* Clear all STATUS2 events via R/W */
	debug("%s entry: STATUS2 = %08x\n", __func__, reg);

	debug("%s entry: COMMAND = %08x\n", __func__, readl(&regs->command));

	clrsetbits_le32(&regs->command2, SLINK_CMD2_SS_EN_MASK,
			SLINK_CMD2_TXEN | SLINK_CMD2_RXEN |
			(spi_chip_select(dev) << SLINK_CMD2_SS_EN_SHIFT));
	debug("%s entry: COMMAND2 = %08x\n", __func__, readl(&regs->command2));

	if (flags & SPI_XFER_BEGIN)
		spi_cs_activate(dev);

	/* handle data in 32-bit chunks */
	while (num_bytes > 0) {
		int bytes;
		int is_read = 0;
		int tm, i;

		tmpdout = 0;
		bytes = (num_bytes > 4) ?  4 : num_bytes;

		if (dout != NULL) {
			for (i = 0; i < bytes; ++i)
				tmpdout = (tmpdout << 8) | dout[i];
			dout += bytes;
		}

		num_bytes -= bytes;

		clrsetbits_le32(&regs->command, SLINK_CMD_BIT_LENGTH_MASK,
				bytes * 8 - 1);
		writel(tmpdout, &regs->tx_fifo);
		setbits_le32(&regs->command, SLINK_CMD_GO);

		/*
		 * Wait for SPI transmit FIFO to empty, or to time out.
		 * The RX FIFO status will be read and cleared last
		 */
		for (tm = 0, is_read = 0; tm < SPI_TIMEOUT; ++tm) {
			u32 status;

			status = readl(&regs->status);

			/* We can exit when we've had both RX and TX activity */
			if (is_read && (status & SLINK_STAT_TXF_EMPTY))
				break;

			if ((status & (SLINK_STAT_BSY | SLINK_STAT_RDY)) !=
					SLINK_STAT_RDY)
				tm++;

			else if (!(status & SLINK_STAT_RXF_EMPTY)) {
				tmpdin = readl(&regs->rx_fifo);
				is_read = 1;

				/* swap bytes read in */
				if (din != NULL) {
					for (i = bytes - 1; i >= 0; --i) {
						din[i] = tmpdin & 0xff;
						tmpdin >>= 8;
					}
					din += bytes;
				}
			}
		}

		if (tm >= SPI_TIMEOUT)
			ret = tm;

		/* clear ACK RDY, etc. bits */
		writel(readl(&regs->status), &regs->status);
	}

	if (flags & SPI_XFER_END)
		spi_cs_deactivate(dev);

	debug("%s: transfer ended. Value=%08x, status = %08x\n",
	      __func__, tmpdin, readl(&regs->status));

	if (ret) {
		printf("%s: timeout during SPI transfer, tm %d\n",
		       __func__, ret);
		return -1;
	}

	return 0;
}

static int tegra30_spi_set_speed(struct udevice *bus, uint speed)
{
	struct tegra_spi_platdata *plat = bus->platdata;
	struct tegra30_spi_priv *priv = dev_get_priv(bus);

	if (speed > plat->frequency)
		speed = plat->frequency;
	priv->freq = speed;
	debug("%s: regs=%p, speed=%d\n", __func__, priv->regs, priv->freq);

	return 0;
}

static int tegra30_spi_set_mode(struct udevice *bus, uint mode)
{
	struct tegra30_spi_priv *priv = dev_get_priv(bus);
	struct spi_regs *regs = priv->regs;
	u32 reg;

	reg = readl(&regs->command);

	/* Set CPOL and CPHA */
	reg &= ~(SLINK_CMD_IDLE_SCLK_MASK | SLINK_CMD_CK_SDA);
	if (mode & SPI_CPHA)
		reg |= SLINK_CMD_CK_SDA;

	if (mode & SPI_CPOL)
		reg |= SLINK_CMD_IDLE_SCLK_DRIVE_HIGH;
	else
		reg |= SLINK_CMD_IDLE_SCLK_DRIVE_LOW;

	writel(reg, &regs->command);

	priv->mode = mode;
	debug("%s: regs=%p, mode=%d\n", __func__, priv->regs, priv->mode);

	return 0;
}

static const struct dm_spi_ops tegra30_spi_ops = {
	.claim_bus	= tegra30_spi_claim_bus,
	.xfer		= tegra30_spi_xfer,
	.set_speed	= tegra30_spi_set_speed,
	.set_mode	= tegra30_spi_set_mode,
	/*
	 * cs_info is not needed, since we require all chip selects to be
	 * in the device tree explicitly
	 */
};

static const struct udevice_id tegra30_spi_ids[] = {
	{ .compatible = "nvidia,tegra20-slink" },
	{ }
};

U_BOOT_DRIVER(tegra30_spi) = {
	.name	= "tegra20_slink",
	.id	= UCLASS_SPI,
	.of_match = tegra30_spi_ids,
	.ops	= &tegra30_spi_ops,
	.ofdata_to_platdata = tegra30_spi_ofdata_to_platdata,
	.platdata_auto_alloc_size = sizeof(struct tegra_spi_platdata),
	.priv_auto_alloc_size = sizeof(struct tegra30_spi_priv),
	.probe	= tegra30_spi_probe,
};
Commit	Line	Data
b19f5749 AM	1	/*
	2	* NVIDIA Tegra SPI-SLINK controller
	3	*
	4	* Copyright (c) 2010-2013 NVIDIA Corporation
	5	*
5b8031cc	6	* SPDX-License-Identifier: GPL-2.0
b19f5749 AM	7	*/
	8
	9	#include <common.h>
fda6fac3	10	#include <dm.h>
b19f5749	11	#include <asm/io.h>
b19f5749 AM	12	#include <asm/arch/clock.h>
b19f5749 AM	13	#include <asm/arch-tegra/clk_rst.h>
b19f5749 AM	14	#include <spi.h>
b19f5749 AM	15	#include <fdtdec.h>
fda6fac3	16	#include "tegra_spi.h"
b19f5749 AM	17
	18	DECLARE_GLOBAL_DATA_PTR;
	19
7a49ba6e	20	/* COMMAND */
f692248f JT	21	#define SLINK_CMD_ENB BIT(31)
	22	#define SLINK_CMD_GO BIT(30)
	23	#define SLINK_CMD_M_S BIT(28)
5cb1b7b3	24	#define SLINK_CMD_IDLE_SCLK_DRIVE_LOW (0 << 24)
f692248f	25	#define SLINK_CMD_IDLE_SCLK_DRIVE_HIGH BIT(24)
5cb1b7b3 MK	26	#define SLINK_CMD_IDLE_SCLK_PULL_LOW (2 << 24)
	27	#define SLINK_CMD_IDLE_SCLK_PULL_HIGH (3 << 24)
	28	#define SLINK_CMD_IDLE_SCLK_MASK (3 << 24)
f692248f JT	29	#define SLINK_CMD_CK_SDA BIT(21)
	30	#define SLINK_CMD_CS_POL BIT(13)
	31	#define SLINK_CMD_CS_VAL BIT(12)
	32	#define SLINK_CMD_CS_SOFT BIT(11)
	33	#define SLINK_CMD_BIT_LENGTH BIT(4)
76538ec6	34	#define SLINK_CMD_BIT_LENGTH_MASK GENMASK(4, 0)
7a49ba6e	35	/* COMMAND2 */
f692248f JT	36	#define SLINK_CMD2_TXEN BIT(30)
	37	#define SLINK_CMD2_RXEN BIT(31)
	38	#define SLINK_CMD2_SS_EN BIT(18)
7a49ba6e	39	#define SLINK_CMD2_SS_EN_SHIFT 18
76538ec6	40	#define SLINK_CMD2_SS_EN_MASK GENMASK(19, 18)
f692248f	41	#define SLINK_CMD2_CS_ACTIVE_BETWEEN BIT(17)
7a49ba6e	42	/* STATUS */
f692248f JT	43	#define SLINK_STAT_BSY BIT(31)
	44	#define SLINK_STAT_RDY BIT(30)
	45	#define SLINK_STAT_ERR BIT(29)
	46	#define SLINK_STAT_RXF_FLUSH BIT(27)
	47	#define SLINK_STAT_TXF_FLUSH BIT(26)
	48	#define SLINK_STAT_RXF_OVF BIT(25)
	49	#define SLINK_STAT_TXF_UNR BIT(24)
	50	#define SLINK_STAT_RXF_EMPTY BIT(23)
	51	#define SLINK_STAT_RXF_FULL BIT(22)
	52	#define SLINK_STAT_TXF_EMPTY BIT(21)
	53	#define SLINK_STAT_TXF_FULL BIT(20)
	54	#define SLINK_STAT_TXF_OVF BIT(19)
	55	#define SLINK_STAT_RXF_UNR BIT(18)
	56	#define SLINK_STAT_CUR_BLKCNT BIT(15)
7a49ba6e	57	/* STATUS2 */
f692248f JT	58	#define SLINK_STAT2_RXF_FULL_CNT BIT(16)
f692248f JT	59	#define SLINK_STAT2_TXF_FULL_CNT BIT(0)
7a49ba6e AM	60
	61	#define SPI_TIMEOUT 1000
	62	#define TEGRA_SPI_MAX_FREQ 52000000
	63
	64	struct spi_regs {
	65	u32 command; /* SLINK_COMMAND_0 register */
	66	u32 command2; /* SLINK_COMMAND2_0 reg */
	67	u32 status; /* SLINK_STATUS_0 register */
	68	u32 reserved; /* Reserved offset 0C */
	69	u32 mas_data; /* SLINK_MAS_DATA_0 reg */
	70	u32 slav_data; /* SLINK_SLAVE_DATA_0 reg */
	71	u32 dma_ctl; /* SLINK_DMA_CTL_0 register */
	72	u32 status2; /* SLINK_STATUS2_0 reg */
	73	u32 rsvd[56]; /* 0x20 to 0xFF reserved */
	74	u32 tx_fifo; /* SLINK_TX_FIFO_0 reg off 100h */
	75	u32 rsvd2[31]; /* 0x104 to 0x17F reserved */
	76	u32 rx_fifo; /* SLINK_RX_FIFO_0 reg off 180h */
	77	};
	78
fda6fac3	79	struct tegra30_spi_priv {
7a49ba6e	80	struct spi_regs *regs;
b19f5749 AM	81	unsigned int freq;
	82	unsigned int mode;
	83	int periph_id;
	84	int valid;
fda6fac3	85	int last_transaction_us;
b19f5749 AM	86	};
	87
	88	struct tegra_spi_slave {
	89	struct spi_slave slave;
fda6fac3	90	struct tegra30_spi_priv *ctrl;
b19f5749 AM	91	};
b19f5749 AM	92
fda6fac3	93	static int tegra30_spi_ofdata_to_platdata(struct udevice *bus)
b19f5749	94	{
fda6fac3 SG	95	struct tegra_spi_platdata *plat = bus->platdata;
fda6fac3 SG	96	const void *blob = gd->fdt_blob;
e160f7d4	97	int node = dev_of_offset(bus);
b19f5749	98
a821c4af	99	plat->base = devfdt_get_addr(bus);
000f15fa	100	plat->periph_id = clock_decode_periph_id(bus);
b19f5749	101
fda6fac3 SG	102	if (plat->periph_id == PERIPH_ID_NONE) {
	103	debug("%s: could not decode periph id %d\n", __func__,
	104	plat->periph_id);
	105	return -FDT_ERR_NOTFOUND;
b19f5749 AM	106	}
b19f5749 AM	107
fda6fac3 SG	108	/* Use 500KHz as a suitable default */
	109	plat->frequency = fdtdec_get_int(blob, node, "spi-max-frequency",
	110	500000);
	111	plat->deactivate_delay_us = fdtdec_get_int(blob, node,
	112	"spi-deactivate-delay", 0);
	113	debug("%s: base=%#08lx, periph_id=%d, max-frequency=%d, deactivate_delay=%d\n",
	114	__func__, plat->base, plat->periph_id, plat->frequency,
	115	plat->deactivate_delay_us);
b19f5749	116
fda6fac3	117	return 0;
b19f5749 AM	118	}
b19f5749 AM	119
fda6fac3	120	static int tegra30_spi_probe(struct udevice *bus)
b19f5749	121	{
fda6fac3 SG	122	struct tegra_spi_platdata *plat = dev_get_platdata(bus);
fda6fac3 SG	123	struct tegra30_spi_priv *priv = dev_get_priv(bus);
b19f5749	124
fda6fac3	125	priv->regs = (struct spi_regs *)plat->base;
b19f5749	126
fda6fac3 SG	127	priv->last_transaction_us = timer_get_us();
	128	priv->freq = plat->frequency;
	129	priv->periph_id = plat->periph_id;
b19f5749	130
4832c7f5 SW	131	/* Change SPI clock to correct frequency, PLLP_OUT0 source */
	132	clock_start_periph_pll(priv->periph_id, CLOCK_ID_PERIPH,
	133	priv->freq);
	134
fda6fac3	135	return 0;
b19f5749 AM	136	}
b19f5749 AM	137
9694b724	138	static int tegra30_spi_claim_bus(struct udevice *dev)
b19f5749	139	{
9694b724	140	struct udevice *bus = dev->parent;
fda6fac3 SG	141	struct tegra30_spi_priv *priv = dev_get_priv(bus);
fda6fac3 SG	142	struct spi_regs *regs = priv->regs;
b19f5749 AM	143	u32 reg;
	144
	145	/* Change SPI clock to correct frequency, PLLP_OUT0 source */
fda6fac3 SG	146	clock_start_periph_pll(priv->periph_id, CLOCK_ID_PERIPH,
fda6fac3 SG	147	priv->freq);
b19f5749 AM	148
	149	/* Clear stale status here */
	150	reg = SLINK_STAT_RDY \| SLINK_STAT_RXF_FLUSH \| SLINK_STAT_TXF_FLUSH \| \
	151	SLINK_STAT_RXF_UNR \| SLINK_STAT_TXF_OVF;
	152	writel(reg, &regs->status);
	153	debug("%s: STATUS = %08x\n", __func__, readl(&regs->status));
	154
	155	/* Set master mode and sw controlled CS */
	156	reg = readl(&regs->command);
	157	reg \|= SLINK_CMD_M_S \| SLINK_CMD_CS_SOFT;
	158	writel(reg, &regs->command);
	159	debug("%s: COMMAND = %08x\n", __func__, readl(&regs->command));
	160
	161	return 0;
	162	}
	163
fda6fac3	164	static void spi_cs_activate(struct udevice *dev)
b19f5749	165	{
fda6fac3 SG	166	struct udevice *bus = dev->parent;
	167	struct tegra_spi_platdata *pdata = dev_get_platdata(bus);
	168	struct tegra30_spi_priv *priv = dev_get_priv(bus);
	169
	170	/* If it's too soon to do another transaction, wait */
	171	if (pdata->deactivate_delay_us &&
	172	priv->last_transaction_us) {
	173	ulong delay_us; /* The delay completed so far */
	174	delay_us = timer_get_us() - priv->last_transaction_us;
	175	if (delay_us < pdata->deactivate_delay_us)
	176	udelay(pdata->deactivate_delay_us - delay_us);
	177	}
b19f5749 AM	178
b19f5749 AM	179	/* CS is negated on Tegra, so drive a 1 to get a 0 */
fda6fac3	180	setbits_le32(&priv->regs->command, SLINK_CMD_CS_VAL);
b19f5749 AM	181	}
b19f5749 AM	182
fda6fac3	183	static void spi_cs_deactivate(struct udevice *dev)
b19f5749	184	{
fda6fac3 SG	185	struct udevice *bus = dev->parent;
	186	struct tegra_spi_platdata *pdata = dev_get_platdata(bus);
	187	struct tegra30_spi_priv *priv = dev_get_priv(bus);
b19f5749 AM	188
b19f5749 AM	189	/* CS is negated on Tegra, so drive a 0 to get a 1 */
fda6fac3 SG	190	clrbits_le32(&priv->regs->command, SLINK_CMD_CS_VAL);
	191
	192	/* Remember time of this transaction so we can honour the bus delay */
	193	if (pdata->deactivate_delay_us)
	194	priv->last_transaction_us = timer_get_us();
b19f5749 AM	195	}
b19f5749 AM	196
fda6fac3 SG	197	static int tegra30_spi_xfer(struct udevice *dev, unsigned int bitlen,
	198	const void data_out, void data_in,
	199	unsigned long flags)
b19f5749	200	{
fda6fac3 SG	201	struct udevice *bus = dev->parent;
	202	struct tegra30_spi_priv *priv = dev_get_priv(bus);
	203	struct spi_regs *regs = priv->regs;
b19f5749 AM	204	u32 reg, tmpdout, tmpdin = 0;
	205	const u8 *dout = data_out;
	206	u8 *din = data_in;
	207	int num_bytes;
	208	int ret;
	209
	210	debug("%s: slave %u:%u dout %p din %p bitlen %u\n",
fda6fac3	211	__func__, bus->seq, spi_chip_select(dev), dout, din, bitlen);
b19f5749 AM	212	if (bitlen % 8)
	213	return -1;
	214	num_bytes = bitlen / 8;
	215
	216	ret = 0;
	217
	218	reg = readl(&regs->status);
	219	writel(reg, &regs->status); /* Clear all SPI events via R/W */
	220	debug("%s entry: STATUS = %08x\n", __func__, reg);
	221
	222	reg = readl(&regs->status2);
	223	writel(reg, &regs->status2); /* Clear all STATUS2 events via R/W */
	224	debug("%s entry: STATUS2 = %08x\n", __func__, reg);
	225
	226	debug("%s entry: COMMAND = %08x\n", __func__, readl(&regs->command));
	227
	228	clrsetbits_le32(&regs->command2, SLINK_CMD2_SS_EN_MASK,
	229	SLINK_CMD2_TXEN \| SLINK_CMD2_RXEN \|
fda6fac3	230	(spi_chip_select(dev) << SLINK_CMD2_SS_EN_SHIFT));
b19f5749 AM	231	debug("%s entry: COMMAND2 = %08x\n", __func__, readl(&regs->command2));
	232
	233	if (flags & SPI_XFER_BEGIN)
fda6fac3	234	spi_cs_activate(dev);
b19f5749 AM	235
	236	/* handle data in 32-bit chunks */
	237	while (num_bytes > 0) {
	238	int bytes;
	239	int is_read = 0;
	240	int tm, i;
	241
	242	tmpdout = 0;
	243	bytes = (num_bytes > 4) ? 4 : num_bytes;
	244
	245	if (dout != NULL) {
	246	for (i = 0; i < bytes; ++i)
	247	tmpdout = (tmpdout << 8) \| dout[i];
	248	dout += bytes;
	249	}
	250
	251	num_bytes -= bytes;
	252
	253	clrsetbits_le32(&regs->command, SLINK_CMD_BIT_LENGTH_MASK,
	254	bytes * 8 - 1);
	255	writel(tmpdout, &regs->tx_fifo);
	256	setbits_le32(&regs->command, SLINK_CMD_GO);
	257
	258	/*
	259	* Wait for SPI transmit FIFO to empty, or to time out.
	260	* The RX FIFO status will be read and cleared last
	261	*/
	262	for (tm = 0, is_read = 0; tm < SPI_TIMEOUT; ++tm) {
	263	u32 status;
	264
	265	status = readl(&regs->status);
	266
	267	/* We can exit when we've had both RX and TX activity */
	268	if (is_read && (status & SLINK_STAT_TXF_EMPTY))
	269	break;
	270
	271	if ((status & (SLINK_STAT_BSY \| SLINK_STAT_RDY)) !=
	272	SLINK_STAT_RDY)
	273	tm++;
	274
	275	else if (!(status & SLINK_STAT_RXF_EMPTY)) {
	276	tmpdin = readl(&regs->rx_fifo);
	277	is_read = 1;
	278
	279	/* swap bytes read in */
	280	if (din != NULL) {
	281	for (i = bytes - 1; i >= 0; --i) {
	282	din[i] = tmpdin & 0xff;
	283	tmpdin >>= 8;
	284	}
	285	din += bytes;
	286	}
	287	}
	288	}
	289
	290	if (tm >= SPI_TIMEOUT)
	291	ret = tm;
	292
	293	/* clear ACK RDY, etc. bits */
	294	writel(readl(&regs->status), &regs->status);
	295	}
	296
	297	if (flags & SPI_XFER_END)
fda6fac3	298	spi_cs_deactivate(dev);
b19f5749 AM	299
	300	debug("%s: transfer ended. Value=%08x, status = %08x\n",
	301	__func__, tmpdin, readl(&regs->status));
	302
	303	if (ret) {
	304	printf("%s: timeout during SPI transfer, tm %d\n",
	305	__func__, ret);
	306	return -1;
	307	}
	308
	309	return 0;
	310	}
fda6fac3 SG	311
	312	static int tegra30_spi_set_speed(struct udevice *bus, uint speed)
	313	{
	314	struct tegra_spi_platdata *plat = bus->platdata;
	315	struct tegra30_spi_priv *priv = dev_get_priv(bus);
	316
	317	if (speed > plat->frequency)
	318	speed = plat->frequency;
	319	priv->freq = speed;
	320	debug("%s: regs=%p, speed=%d\n", __func__, priv->regs, priv->freq);
	321
	322	return 0;
	323	}
	324
	325	static int tegra30_spi_set_mode(struct udevice *bus, uint mode)
	326	{
	327	struct tegra30_spi_priv *priv = dev_get_priv(bus);
5cb1b7b3 MK	328	struct spi_regs *regs = priv->regs;
	329	u32 reg;
	330
	331	reg = readl(&regs->command);
	332
	333	/* Set CPOL and CPHA */
	334	reg &= ~(SLINK_CMD_IDLE_SCLK_MASK \| SLINK_CMD_CK_SDA);
	335	if (mode & SPI_CPHA)
	336	reg \|= SLINK_CMD_CK_SDA;
	337
	338	if (mode & SPI_CPOL)
	339	reg \|= SLINK_CMD_IDLE_SCLK_DRIVE_HIGH;
	340	else
	341	reg \|= SLINK_CMD_IDLE_SCLK_DRIVE_LOW;
	342
	343	writel(reg, &regs->command);
fda6fac3 SG	344
	345	priv->mode = mode;
	346	debug("%s: regs=%p, mode=%d\n", __func__, priv->regs, priv->mode);
	347
	348	return 0;
	349	}
	350
	351	static const struct dm_spi_ops tegra30_spi_ops = {
	352	.claim_bus = tegra30_spi_claim_bus,
	353	.xfer = tegra30_spi_xfer,
	354	.set_speed = tegra30_spi_set_speed,
	355	.set_mode = tegra30_spi_set_mode,
	356	/*
	357	* cs_info is not needed, since we require all chip selects to be
	358	* in the device tree explicitly
	359	*/
	360	};
	361
	362	static const struct udevice_id tegra30_spi_ids[] = {
	363	{ .compatible = "nvidia,tegra20-slink" },
	364	{ }
	365	};
	366
	367	U_BOOT_DRIVER(tegra30_spi) = {
	368	.name = "tegra20_slink",
	369	.id = UCLASS_SPI,
	370	.of_match = tegra30_spi_ids,
	371	.ops = &tegra30_spi_ops,
	372	.ofdata_to_platdata = tegra30_spi_ofdata_to_platdata,
	373	.platdata_auto_alloc_size = sizeof(struct tegra_spi_platdata),
	374	.priv_auto_alloc_size = sizeof(struct tegra30_spi_priv),
fda6fac3 SG	375	.probe = tegra30_spi_probe,
fda6fac3 SG	376	};