drivers/spi/tegra1x4_spi.c - mirrors/cros/chromiumos/third_party/u-boot - Git at Google

 /*
  * NVIDIA Tegra SPI controller (T114 and later)
  *
  * Copyright (c) 2010-2013 NVIDIA Corporation
  *
  * See file CREDITS for list of people who contributed to this
  * project.
  *
  * This software is licensed under the terms of the GNU General Public
  * License version 2, as published by the Free Software Foundation, and
  * may be copied, distributed, and modified under those terms.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  * MA 02111-1307 USA
  */

 #include <common.h>
 #include <malloc.h>
 #include <asm/io.h>
 #include <asm/errno.h>
 #include <asm/gpio.h>
 #include <asm/arch/clock.h>
 #include <asm/arch/clk_rst.h>
 #include <asm/arch-tegra/tegra1x4_spi.h>
 #include <spi.h>
 #include <fdtdec.h>
 #include <asm/arch/pinmux.h>

 DECLARE_GLOBAL_DATA_PTR;

 /* COMMAND1 */
 #define SPI_CMD1_GO			(1 << 31)
 #define SPI_CMD1_M_S			(1 << 30)
 #define SPI_CMD1_MODE_MASK		0x3
 #define SPI_CMD1_MODE_SHIFT		28
 #define SPI_CMD1_CS_SEL_MASK		0x3
 #define SPI_CMD1_CS_SEL_SHIFT		26
 #define SPI_CMD1_CS_POL_INACTIVE3	(1 << 25)
 #define SPI_CMD1_CS_POL_INACTIVE2	(1 << 24)
 #define SPI_CMD1_CS_POL_INACTIVE1	(1 << 23)
 #define SPI_CMD1_CS_POL_INACTIVE0	(1 << 22)
 #define SPI_CMD1_CS_SW_HW		(1 << 21)
 #define SPI_CMD1_CS_SW_VAL		(1 << 20)
 #define SPI_CMD1_IDLE_SDA_MASK		0x3
 #define SPI_CMD1_IDLE_SDA_SHIFT		18
 #define SPI_CMD1_BIDIR			(1 << 17)
 #define SPI_CMD1_LSBI_FE		(1 << 16)
 #define SPI_CMD1_LSBY_FE		(1 << 15)
 #define SPI_CMD1_BOTH_EN_BIT		(1 << 14)
 #define SPI_CMD1_BOTH_EN_BYTE		(1 << 13)
 #define SPI_CMD1_RX_EN			(1 << 12)
 #define SPI_CMD1_TX_EN			(1 << 11)
 #define SPI_CMD1_PACKED			(1 << 5)
 #define SPI_CMD1_BIT_LEN_MASK		0x1F
 #define SPI_CMD1_BIT_LEN_SHIFT		0

 /* COMMAND2 */
 #define SPI_CMD2_TX_CLK_TAP_DELAY	(1 << 6)
 #define SPI_CMD2_TX_CLK_TAP_DELAY_MASK	(0x3F << 6)
 #define SPI_CMD2_RX_CLK_TAP_DELAY	(1 << 0)
 #define SPI_CMD2_RX_CLK_TAP_DELAY_MASK	(0x3F << 0)

 /* TRANSFER STATUS */
 #define SPI_XFER_STS_RDY		(1 << 30)

 /* FIFO STATUS */
 #define SPI_FIFO_STS_CS_INACTIVE	(1 << 31)
 #define SPI_FIFO_STS_FRAME_END		(1 << 30)
 #define SPI_FIFO_STS_RX_FIFO_FLUSH	(1 << 15)
 #define SPI_FIFO_STS_TX_FIFO_FLUSH	(1 << 14)
 #define SPI_FIFO_STS_ERR		(1 << 8)
 #define SPI_FIFO_STS_TX_FIFO_OVF	(1 << 7)
 #define SPI_FIFO_STS_TX_FIFO_UNR	(1 << 6)
 #define SPI_FIFO_STS_RX_FIFO_OVF	(1 << 5)
 #define SPI_FIFO_STS_RX_FIFO_UNR	(1 << 4)
 #define SPI_FIFO_STS_TX_FIFO_FULL	(1 << 3)
 #define SPI_FIFO_STS_TX_FIFO_EMPTY	(1 << 2)
 #define SPI_FIFO_STS_RX_FIFO_FULL	(1 << 1)
 #define SPI_FIFO_STS_RX_FIFO_EMPTY	(1 << 0)

 #define SPI_TIMEOUT		1000
 #define TEGRA_SPI_MAX_FREQ	52000000
 #define SPI_REPLY_TIMEOUT_MS	100

 struct spi_regs {
 	u32 command1;	/* 000:SPI_COMMAND1 register */
 	u32 command2;	/* 004:SPI_COMMAND2 register */
 	u32 timing1;	/* 008:SPI_CS_TIM1 register */
 	u32 timing2;	/* 00c:SPI_CS_TIM2 register */
 	u32 xfer_status;/* 010:SPI_TRANS_STATUS register */
 	u32 fifo_status;/* 014:SPI_FIFO_STATUS register */
 	u32 tx_data;	/* 018:SPI_TX_DATA register */
 	u32 rx_data;	/* 01c:SPI_RX_DATA register */
 	u32 dma_ctl;	/* 020:SPI_DMA_CTL register */
 	u32 dma_blk;	/* 024:SPI_DMA_BLK register */
 	u32 rsvd[56];	/* 028-107 reserved */
 	u32 tx_fifo;	/* 108:SPI_FIFO1 register */
 	u32 rsvd2[31];	/* 10c-187 reserved */
 	u32 rx_fifo;	/* 188:SPI_FIFO2 register */
 	u32 spare_ctl;	/* 18c:SPI_SPARE_CTRL register */
 };

 struct tegra_spi_ctrl {
 	struct spi_regs *regs;
 	unsigned int freq;
 	unsigned int mode;
 	int periph_id;
 	int valid;
 	int node;
 	uint deactivate_delay_us;	/* Delay to wait after deactivate */
 	int cs_pinmux;
 };

 struct tegra_spi_slave {
 	struct spi_slave slave;
 	struct tegra_spi_ctrl *ctrl;
 	ulong last_transaction_us;	/* Time of the last transaction end */
 };

 static struct tegra_spi_ctrl spi_ctrls[CONFIG_TEGRA114_SPI_CTRLS];

 static inline struct tegra_spi_slave *to_tegra_spi(struct spi_slave *slave)
 {
 	return container_of(slave, struct tegra_spi_slave, slave);
 }

 int tegra114_spi_cs_is_valid(unsigned int bus, unsigned int cs)
 {
 	if (bus >= CONFIG_TEGRA114_SPI_CTRLS || cs > 3 || !spi_ctrls[bus].valid)
 		return 0;
 	else
 		return 1;
 }

 struct spi_slave *tegra114_spi_setup_slave(unsigned int bus, unsigned int cs,
 		unsigned int max_hz, unsigned int mode)
 {
 	struct tegra_spi_slave *spi;

 	debug("%s: bus: %u, cs: %u, max_hz: %u, mode: %u\n", __func__,
 		bus, cs, max_hz, mode);

 	if (!spi_cs_is_valid(bus, cs)) {
 		printf("SPI error: unsupported bus %d / chip select %d\n",
 		       bus, cs);
 		return NULL;
 	}

 	if (max_hz > TEGRA_SPI_MAX_FREQ) {
 		printf("SPI error: unsupported frequency %d Hz. Max frequency"
 			" is %d Hz\n", max_hz, TEGRA_SPI_MAX_FREQ);
 		return NULL;
 	}

 	spi = spi_alloc_slave(struct tegra_spi_slave, bus, cs);
 	if (!spi) {
 		printf("SPI error: malloc of SPI structure failed\n");
 		return NULL;
 	}

 	spi->ctrl = &spi_ctrls[bus];
 	if (!spi->ctrl) {
 		printf("SPI error: could not find controller for bus %d\n",
 		       bus);
 		return NULL;
 	}

 	if (max_hz < spi->ctrl->freq) {
 		debug("%s: limiting frequency from %u to %u\n", __func__,
 		      spi->ctrl->freq, max_hz);
 		spi->ctrl->freq = max_hz;
 	}
 	spi->ctrl->mode = mode;
 	spi->last_transaction_us = timer_get_us();

 	return &spi->slave;
 }

 void tegra114_spi_free_slave(struct spi_slave *slave)
 {
 	struct tegra_spi_slave *spi = to_tegra_spi(slave);

 	free(spi);
 }

 int tegra114_spi_init(int *node_list, int count)
 {
 	struct tegra_spi_ctrl *ctrl;
 	int i;
 	int node = 0;
 	int found = 0;

 	for (i = 0; i < count; i++) {
 		ctrl = &spi_ctrls[i];
 		node = node_list[i];

 		ctrl->regs = (struct spi_regs *)fdtdec_get_addr(gd->fdt_blob,
 								 node, "reg");
 		if ((fdt_addr_t)ctrl->regs == FDT_ADDR_T_NONE) {
 			debug("%s: no spi register found\n", __func__);
 			continue;
 		}
 		ctrl->freq = fdtdec_get_int(gd->fdt_blob, node,
 					    "spi-max-frequency", 0);
 		if (!ctrl->freq) {
 			debug("%s: no spi max frequency found\n", __func__);
 			continue;
 		}
 		ctrl->cs_pinmux = fdtdec_get_int(gd->fdt_blob, node,
 						 "nvidia,cs-pinmux", 0);
 		if (!ctrl->cs_pinmux) {
 			debug("%s: cs-pinmux must be specified.\n", __func__);
 			continue;
 		}

 		ctrl->periph_id = clock_decode_periph_id(gd->fdt_blob, node);
 		if (ctrl->periph_id == PERIPH_ID_NONE) {
 			debug("%s: could not decode periph id\n", __func__);
 			continue;
 		}
 		ctrl->valid = 1;
 		found = 1;

 		ctrl->node = node;
 		ctrl->deactivate_delay_us = fdtdec_get_int(gd->fdt_blob, node,
 						"spi-deactivate-delay", 0);

 		debug("%s: found controller at %p, freq = %u, periph_id = %d\n",
 		      __func__, ctrl->regs, ctrl->freq, ctrl->periph_id);
 	}

 	return !found;
 }

 int tegra114_spi_claim_bus(struct spi_slave *slave)
 {
 	struct tegra_spi_slave *spi = to_tegra_spi(slave);
 	struct spi_regs *regs = spi->ctrl->regs;

 	/*
 	 * Change SPI clock to correct frequency, PLLP_OUT0 source
 	 *
 	 * Note that calling clock_start_periph_pll() will reset the SPI
 	 * controller, and that will cause CS line to be asserted.
 	 *
 	 * We tristate (and pull-up) the CS line before the call, so the line
 	 * won't be driven out low during reset.
 	 */
 	if (spi->ctrl->cs_pinmux) {
 		pinmux_set_pullupdown(spi->ctrl->cs_pinmux, PMUX_PULL_UP);
 		pinmux_tristate_enable(spi->ctrl->cs_pinmux);
 	}
 	clock_start_periph_pll(spi->ctrl->periph_id, CLOCK_ID_PERIPH,
 			       spi->ctrl->freq);
 	if (spi->ctrl->cs_pinmux) {
 		pinmux_set_pullupdown(spi->ctrl->cs_pinmux, PMUX_PULL_NORMAL);
 		pinmux_tristate_disable(spi->ctrl->cs_pinmux);
 	}

 	/* Clear stale status here */
 	setbits_le32(&regs->fifo_status,
 		     SPI_FIFO_STS_ERR		|
 		     SPI_FIFO_STS_TX_FIFO_OVF	|
 		     SPI_FIFO_STS_TX_FIFO_UNR	|
 		     SPI_FIFO_STS_RX_FIFO_OVF	|
 		     SPI_FIFO_STS_RX_FIFO_UNR	|
 		     SPI_FIFO_STS_TX_FIFO_FULL	|
 		     SPI_FIFO_STS_TX_FIFO_EMPTY	|
 		     SPI_FIFO_STS_RX_FIFO_FULL	|
 		     SPI_FIFO_STS_RX_FIFO_EMPTY);
 	debug("%s: FIFO STATUS = %08x\n", __func__, readl(&regs->fifo_status));

 	/* Set master mode and sw controlled CS */
 	setbits_le32(&regs->command1, SPI_CMD1_M_S | SPI_CMD1_CS_SW_HW |
 		     (spi->ctrl->mode << SPI_CMD1_MODE_SHIFT));
 	debug("%s: COMMAND1 = %08x\n", __func__, readl(&regs->command1));

 	return 0;
 }

 void tegra114_spi_cs_activate(struct spi_slave *slave)
 {
 	struct tegra_spi_slave *spi = to_tegra_spi(slave);
 	struct spi_regs *regs = spi->ctrl->regs;
 	ulong delay_us;			/* The delay completed so far */

 	/* If it's too soon to do another transaction, wait */
 	if (spi->ctrl->deactivate_delay_us && spi->last_transaction_us) {
 		delay_us = timer_get_us() - spi->last_transaction_us;
 		if (delay_us < spi->ctrl->deactivate_delay_us) {
 			debug("%s: delaying %lu uSec\n", __func__,
 			      spi->ctrl->deactivate_delay_us - delay_us);
 			udelay(spi->ctrl->deactivate_delay_us - delay_us);
 		}
 	}
 	clrbits_le32(&regs->command1, SPI_CMD1_CS_SW_VAL);
 }

 void tegra114_spi_cs_deactivate(struct spi_slave *slave)
 {
 	struct tegra_spi_slave *spi = to_tegra_spi(slave);
 	struct spi_regs *regs = spi->ctrl->regs;

 	setbits_le32(&regs->command1, SPI_CMD1_CS_SW_VAL);

 	/* Remember time of this transaction so we can honor the bus delay */
 	if (spi->ctrl->deactivate_delay_us)
 		spi->last_transaction_us = timer_get_us();

 	debug("%s: deactivate_delay_us = %u, last_transaction_us = %lu\n",
 	      __func__, spi->ctrl->deactivate_delay_us,
 	      spi->last_transaction_us);
 }

 void spi_set_deactivate_delay_us(struct spi_slave *slave, int delay_us)
 {
 	struct tegra_spi_slave *spi = to_tegra_spi(slave);

 	spi->ctrl->deactivate_delay_us = delay_us;

 	debug("%s: deactivate_delay_us set to %d\n",
 	      __func__, spi->ctrl->deactivate_delay_us);
 }

 static int spi_check_fifo_error(int fifo_status)
 {
 	int ret = 0;

 	if (fifo_status & SPI_FIFO_STS_ERR) {
 		ret = fifo_status;
 		debug("%s: got a fifo error: ", __func__);
 		if (fifo_status & SPI_FIFO_STS_TX_FIFO_OVF)
 			debug("tx FIFO overflow ");
 		if (fifo_status & SPI_FIFO_STS_TX_FIFO_UNR)
 			debug("tx FIFO underrun ");
 		if (fifo_status & SPI_FIFO_STS_RX_FIFO_OVF)
 			debug("rx FIFO overflow ");
 		if (fifo_status & SPI_FIFO_STS_RX_FIFO_UNR)
 			debug("rx FIFO underrun ");
 		if (fifo_status & SPI_FIFO_STS_TX_FIFO_FULL)
 			debug("tx FIFO full ");
 		if (fifo_status & SPI_FIFO_STS_TX_FIFO_EMPTY)
 			debug("tx FIFO empty ");
 		if (fifo_status & SPI_FIFO_STS_RX_FIFO_FULL)
 			debug("rx FIFO full ");
 		if (fifo_status & SPI_FIFO_STS_RX_FIFO_EMPTY)
 			debug("rx FIFO empty ");
 		debug("\n");
 	} else {
 		/* no error, but fifo is still empty, set as an error */
 		if (fifo_status & SPI_FIFO_STS_RX_FIFO_EMPTY) {
 			ret = SPI_FIFO_STS_RX_FIFO_EMPTY;
 			debug("%s: rx FIFO should not be empty\n", __func__);
 		}
 	}

 	return ret;
 }

 /**
  * Output number of 'bytes' of data from dout to SPI interface.
  *
  * If out_bytes is 0 or if dout is NULL, data of 0 is output to SPI interface.
  *
  * @param regs		pointer to SPI register structure
  * @param dout		data is output from this pointer
  * @param bytes		# of bytes to send, must be <= 4
  * @param out_bytes	a counter to keep track # of bytes to output from dout;
  *			will be updated by this routine if data are outputted
  *			from dout
  * @return # of bytes are output from dout.
  */
 static int spi_out_data(struct spi_regs *regs, const u8 *dout, int bytes,
 			int *out_bytes)
 {
 	int tmpdout;
 	int dout_len;

 	if (dout && (*out_bytes > 0)) {
 		memcpy((void *)&tmpdout, (void *)dout, bytes);
 		*out_bytes -= bytes;
 		dout_len = bytes;
 	} else {
 		tmpdout = 0;
 		dout_len = 0;
 	}

 	clrsetbits_le32(&regs->command1,
 			SPI_CMD1_BIT_LEN_MASK << SPI_CMD1_BIT_LEN_SHIFT,
 			(bytes * 8 - 1) << SPI_CMD1_BIT_LEN_SHIFT);
 	writel(tmpdout, &regs->tx_fifo);
 	setbits_le32(&regs->command1, SPI_CMD1_GO);

 	return dout_len;
 }

 int tegra114_spi_xfer(struct spi_slave *slave, unsigned int bitlen,
 		const void *data_out, void *data_in, unsigned long flags)
 {
 	struct tegra_spi_slave *spi = to_tegra_spi(slave);
 	struct spi_regs *regs = spi->ctrl->regs;
 	u32 tmpdin = 0;
 	const u8 *dout = data_out;
 	u8 *din = data_in;
 	int num_bytes, out_bytes;
 	int ret;
 	int found = 1;
 	u32 max_timeout_ms = 0;
 	u32 start_time = 0;
 	unsigned header = slave->frame_header;

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

 	if (slave->half_duplex) {
 		found = 0;
 		max_timeout_ms = slave->max_timeout_ms;
 		if (max_timeout_ms == 0)
 			max_timeout_ms = SPI_REPLY_TIMEOUT_MS;

 		start_time = get_timer(0);
 	}

 	ret = 0;

 	/* clear all error status bits */
 	writel(readl(&regs->fifo_status), &regs->fifo_status);

 	/* clear ready bit */
 	setbits_le32(&regs->xfer_status, SPI_XFER_STS_RDY);

 	clrsetbits_le32(&regs->command1,
 			SPI_CMD1_LSBI_FE | SPI_CMD1_LSBY_FE,
 			SPI_CMD1_RX_EN | SPI_CMD1_TX_EN |
 			(slave->cs << SPI_CMD1_CS_SEL_SHIFT));

 	/* set xfer size to 1 block (32 bits) */
 	writel(0, &regs->dma_blk);

 	if (flags & SPI_XFER_BEGIN)
 		spi_cs_activate(slave);

 	/* handle data in 32-bit chunks */
 	while (num_bytes > 0) {
 		int bytes;
 		int tm;
 		u8 *pheader;
 		u32 fifo_status, xfer_status;

 		if (!found)
 			if (get_timer(start_time) > max_timeout_ms) {
 				printf("%s: did not get reply in %u ms\n",
 				       __func__, max_timeout_ms);
 				ret = -EIO;
 				break;
 			}

 		/* Send out data, 4 bytes a time */
 		bytes = (num_bytes > 4) ?  4 : num_bytes;
 		dout += spi_out_data(regs, dout, bytes, &out_bytes);

 		/*
 		 * Wait for SPI transmit FIFO to empty, or to time out.
 		 * The RX FIFO status will be read and cleared last
 		 */
 		for (tm = 0; tm < SPI_TIMEOUT; ++tm) {
 			xfer_status = readl(&regs->xfer_status);
 			if (xfer_status & SPI_XFER_STS_RDY)
 				break;
 		}

 		if (tm >= SPI_TIMEOUT) {
 			debug("%s: timed out waiting for STS_RDY\n", __func__);
 			ret = tm;
 			break;	/* break out of while (num_bytes > 0) loop */
 		}

 		/* clear RDY status */
 		writel(SPI_XFER_STS_RDY, &regs->xfer_status);

 		/* check if there is any FIFO error */
 		fifo_status = readl(&regs->fifo_status);
 		ret = spi_check_fifo_error(fifo_status);
 		if (ret)
 			/* break out of while loop if there is any fifo error */
 			break;

 		/* no error, read RX FIFO */
 		tmpdin = readl(&regs->rx_fifo);

 		/* process input package */
 		if (din) {
 			if (found) {
 				memcpy(din, &tmpdin, bytes);
 				din += bytes;
 			} else {
 				pheader = memchr(&tmpdin, header, bytes);
 				if (pheader) {
 					int len;

 					found = 1;
 					/* determine how many bytes to copy */
 					len = pheader - (u8 *)&tmpdin;
 					bytes -= (len + 1);
 					memcpy(din, pheader + 1, bytes);
 					din += bytes;
 				} else {
 					bytes = 0;
 				}
 			}
 		}

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

 		num_bytes -= bytes;
 	}

 	if (flags & SPI_XFER_END)
 		spi_cs_deactivate(slave);

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

 	return 0;
 }

 #ifdef CONFIG_OF_CONTROL
 /**
  * Get the SPI bus for an fdt node
  *
  * @param blob         Device tree blob
  * @param spi_node     cached pointer to the SPI interface this node belongs to
  * @return spi bus # if ok, -1 on error
  */
 int spi_get_bus_by_node(const void *blob, unsigned spi_node)
 {
 	int i;

 	for (i = 0; i < ARRAY_SIZE(spi_ctrls); i++)
 		if (spi_ctrls[i].node == spi_node)
 			return i;
 	return -1;
 }
 #endif
	/*
	* NVIDIA Tegra SPI controller (T114 and later)
	*
	* Copyright (c) 2010-2013 NVIDIA Corporation
	*
	* See file CREDITS for list of people who contributed to this
	* project.
	*
	* This software is licensed under the terms of the GNU General Public
	* License version 2, as published by the Free Software Foundation, and
	* may be copied, distributed, and modified under those terms.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
	* MA 02111-1307 USA
	*/

	#include <common.h>
	#include <malloc.h>
	#include <asm/io.h>
	#include <asm/errno.h>
	#include <asm/gpio.h>
	#include <asm/arch/clock.h>
	#include <asm/arch/clk_rst.h>
	#include <asm/arch-tegra/tegra1x4_spi.h>
	#include <spi.h>
	#include <fdtdec.h>
	#include <asm/arch/pinmux.h>

	DECLARE_GLOBAL_DATA_PTR;

	/* COMMAND1 */
	#define SPI_CMD1_GO (1 << 31)
	#define SPI_CMD1_M_S (1 << 30)
	#define SPI_CMD1_MODE_MASK 0x3
	#define SPI_CMD1_MODE_SHIFT 28
	#define SPI_CMD1_CS_SEL_MASK 0x3
	#define SPI_CMD1_CS_SEL_SHIFT 26
	#define SPI_CMD1_CS_POL_INACTIVE3 (1 << 25)
	#define SPI_CMD1_CS_POL_INACTIVE2 (1 << 24)
	#define SPI_CMD1_CS_POL_INACTIVE1 (1 << 23)
	#define SPI_CMD1_CS_POL_INACTIVE0 (1 << 22)
	#define SPI_CMD1_CS_SW_HW (1 << 21)
	#define SPI_CMD1_CS_SW_VAL (1 << 20)
	#define SPI_CMD1_IDLE_SDA_MASK 0x3
	#define SPI_CMD1_IDLE_SDA_SHIFT 18
	#define SPI_CMD1_BIDIR (1 << 17)
	#define SPI_CMD1_LSBI_FE (1 << 16)
	#define SPI_CMD1_LSBY_FE (1 << 15)
	#define SPI_CMD1_BOTH_EN_BIT (1 << 14)
	#define SPI_CMD1_BOTH_EN_BYTE (1 << 13)
	#define SPI_CMD1_RX_EN (1 << 12)
	#define SPI_CMD1_TX_EN (1 << 11)
	#define SPI_CMD1_PACKED (1 << 5)
	#define SPI_CMD1_BIT_LEN_MASK 0x1F
	#define SPI_CMD1_BIT_LEN_SHIFT 0

	/* COMMAND2 */
	#define SPI_CMD2_TX_CLK_TAP_DELAY (1 << 6)
	#define SPI_CMD2_TX_CLK_TAP_DELAY_MASK (0x3F << 6)
	#define SPI_CMD2_RX_CLK_TAP_DELAY (1 << 0)
	#define SPI_CMD2_RX_CLK_TAP_DELAY_MASK (0x3F << 0)

	/* TRANSFER STATUS */
	#define SPI_XFER_STS_RDY (1 << 30)

	/* FIFO STATUS */
	#define SPI_FIFO_STS_CS_INACTIVE (1 << 31)
	#define SPI_FIFO_STS_FRAME_END (1 << 30)
	#define SPI_FIFO_STS_RX_FIFO_FLUSH (1 << 15)
	#define SPI_FIFO_STS_TX_FIFO_FLUSH (1 << 14)
	#define SPI_FIFO_STS_ERR (1 << 8)
	#define SPI_FIFO_STS_TX_FIFO_OVF (1 << 7)
	#define SPI_FIFO_STS_TX_FIFO_UNR (1 << 6)
	#define SPI_FIFO_STS_RX_FIFO_OVF (1 << 5)
	#define SPI_FIFO_STS_RX_FIFO_UNR (1 << 4)
	#define SPI_FIFO_STS_TX_FIFO_FULL (1 << 3)
	#define SPI_FIFO_STS_TX_FIFO_EMPTY (1 << 2)
	#define SPI_FIFO_STS_RX_FIFO_FULL (1 << 1)
	#define SPI_FIFO_STS_RX_FIFO_EMPTY (1 << 0)

	#define SPI_TIMEOUT 1000
	#define TEGRA_SPI_MAX_FREQ 52000000
	#define SPI_REPLY_TIMEOUT_MS 100

	struct spi_regs {
	u32 command1; /* 000:SPI_COMMAND1 register */
	u32 command2; /* 004:SPI_COMMAND2 register */
	u32 timing1; /* 008:SPI_CS_TIM1 register */
	u32 timing2; /* 00c:SPI_CS_TIM2 register */
	u32 xfer_status;/* 010:SPI_TRANS_STATUS register */
	u32 fifo_status;/* 014:SPI_FIFO_STATUS register */
	u32 tx_data; /* 018:SPI_TX_DATA register */
	u32 rx_data; /* 01c:SPI_RX_DATA register */
	u32 dma_ctl; /* 020:SPI_DMA_CTL register */
	u32 dma_blk; /* 024:SPI_DMA_BLK register */
	u32 rsvd[56]; /* 028-107 reserved */
	u32 tx_fifo; /* 108:SPI_FIFO1 register */
	u32 rsvd2[31]; /* 10c-187 reserved */
	u32 rx_fifo; /* 188:SPI_FIFO2 register */
	u32 spare_ctl; /* 18c:SPI_SPARE_CTRL register */
	};

	struct tegra_spi_ctrl {
	struct spi_regs *regs;
	unsigned int freq;
	unsigned int mode;
	int periph_id;
	int valid;
	int node;
	uint deactivate_delay_us; /* Delay to wait after deactivate */
	int cs_pinmux;
	};

	struct tegra_spi_slave {
	struct spi_slave slave;
	struct tegra_spi_ctrl *ctrl;
	ulong last_transaction_us; /* Time of the last transaction end */
	};

	static struct tegra_spi_ctrl spi_ctrls[CONFIG_TEGRA114_SPI_CTRLS];

	static inline struct tegra_spi_slave to_tegra_spi(struct spi_slave slave)
	{
	return container_of(slave, struct tegra_spi_slave, slave);
	}

	int tegra114_spi_cs_is_valid(unsigned int bus, unsigned int cs)
	{
	if (bus >= CONFIG_TEGRA114_SPI_CTRLS \|\| cs > 3 \|\| !spi_ctrls[bus].valid)
	return 0;
	else
	return 1;
	}

	struct spi_slave *tegra114_spi_setup_slave(unsigned int bus, unsigned int cs,
	unsigned int max_hz, unsigned int mode)
	{
	struct tegra_spi_slave *spi;

	debug("%s: bus: %u, cs: %u, max_hz: %u, mode: %u\n", __func__,
	bus, cs, max_hz, mode);

	if (!spi_cs_is_valid(bus, cs)) {
	printf("SPI error: unsupported bus %d / chip select %d\n",
	bus, cs);
	return NULL;
	}

	if (max_hz > TEGRA_SPI_MAX_FREQ) {
	printf("SPI error: unsupported frequency %d Hz. Max frequency"
	" is %d Hz\n", max_hz, TEGRA_SPI_MAX_FREQ);
	return NULL;
	}

	spi = spi_alloc_slave(struct tegra_spi_slave, bus, cs);
	if (!spi) {
	printf("SPI error: malloc of SPI structure failed\n");
	return NULL;
	}

	spi->ctrl = &spi_ctrls[bus];
	if (!spi->ctrl) {
	printf("SPI error: could not find controller for bus %d\n",
	bus);
	return NULL;
	}

	if (max_hz < spi->ctrl->freq) {
	debug("%s: limiting frequency from %u to %u\n", __func__,
	spi->ctrl->freq, max_hz);
	spi->ctrl->freq = max_hz;
	}
	spi->ctrl->mode = mode;
	spi->last_transaction_us = timer_get_us();

	return &spi->slave;
	}

	void tegra114_spi_free_slave(struct spi_slave *slave)
	{
	struct tegra_spi_slave *spi = to_tegra_spi(slave);

	free(spi);
	}

	int tegra114_spi_init(int *node_list, int count)
	{
	struct tegra_spi_ctrl *ctrl;
	int i;
	int node = 0;
	int found = 0;

	for (i = 0; i < count; i++) {
	ctrl = &spi_ctrls[i];
	node = node_list[i];

	ctrl->regs = (struct spi_regs *)fdtdec_get_addr(gd->fdt_blob,
	node, "reg");
	if ((fdt_addr_t)ctrl->regs == FDT_ADDR_T_NONE) {
	debug("%s: no spi register found\n", __func__);
	continue;
	}
	ctrl->freq = fdtdec_get_int(gd->fdt_blob, node,
	"spi-max-frequency", 0);
	if (!ctrl->freq) {
	debug("%s: no spi max frequency found\n", __func__);
	continue;
	}
	ctrl->cs_pinmux = fdtdec_get_int(gd->fdt_blob, node,
	"nvidia,cs-pinmux", 0);
	if (!ctrl->cs_pinmux) {
	debug("%s: cs-pinmux must be specified.\n", __func__);
	continue;
	}

	ctrl->periph_id = clock_decode_periph_id(gd->fdt_blob, node);
	if (ctrl->periph_id == PERIPH_ID_NONE) {
	debug("%s: could not decode periph id\n", __func__);
	continue;
	}
	ctrl->valid = 1;
	found = 1;

	ctrl->node = node;
	ctrl->deactivate_delay_us = fdtdec_get_int(gd->fdt_blob, node,
	"spi-deactivate-delay", 0);

	debug("%s: found controller at %p, freq = %u, periph_id = %d\n",
	__func__, ctrl->regs, ctrl->freq, ctrl->periph_id);
	}

	return !found;
	}

	int tegra114_spi_claim_bus(struct spi_slave *slave)
	{
	struct tegra_spi_slave *spi = to_tegra_spi(slave);
	struct spi_regs *regs = spi->ctrl->regs;

	/*
	* Change SPI clock to correct frequency, PLLP_OUT0 source
	*
	* Note that calling clock_start_periph_pll() will reset the SPI
	* controller, and that will cause CS line to be asserted.
	*
	* We tristate (and pull-up) the CS line before the call, so the line
	* won't be driven out low during reset.
	*/
	if (spi->ctrl->cs_pinmux) {
	pinmux_set_pullupdown(spi->ctrl->cs_pinmux, PMUX_PULL_UP);
	pinmux_tristate_enable(spi->ctrl->cs_pinmux);
	}
	clock_start_periph_pll(spi->ctrl->periph_id, CLOCK_ID_PERIPH,
	spi->ctrl->freq);
	if (spi->ctrl->cs_pinmux) {
	pinmux_set_pullupdown(spi->ctrl->cs_pinmux, PMUX_PULL_NORMAL);
	pinmux_tristate_disable(spi->ctrl->cs_pinmux);
	}

	/* Clear stale status here */
	setbits_le32(&regs->fifo_status,
	SPI_FIFO_STS_ERR \|
	SPI_FIFO_STS_TX_FIFO_OVF \|
	SPI_FIFO_STS_TX_FIFO_UNR \|
	SPI_FIFO_STS_RX_FIFO_OVF \|
	SPI_FIFO_STS_RX_FIFO_UNR \|
	SPI_FIFO_STS_TX_FIFO_FULL \|
	SPI_FIFO_STS_TX_FIFO_EMPTY \|
	SPI_FIFO_STS_RX_FIFO_FULL \|
	SPI_FIFO_STS_RX_FIFO_EMPTY);
	debug("%s: FIFO STATUS = %08x\n", __func__, readl(&regs->fifo_status));

	/* Set master mode and sw controlled CS */
	setbits_le32(&regs->command1, SPI_CMD1_M_S \| SPI_CMD1_CS_SW_HW \|
	(spi->ctrl->mode << SPI_CMD1_MODE_SHIFT));
	debug("%s: COMMAND1 = %08x\n", __func__, readl(&regs->command1));

	return 0;
	}

	void tegra114_spi_cs_activate(struct spi_slave *slave)
	{
	struct tegra_spi_slave *spi = to_tegra_spi(slave);
	struct spi_regs *regs = spi->ctrl->regs;
	ulong delay_us; /* The delay completed so far */

	/* If it's too soon to do another transaction, wait */
	if (spi->ctrl->deactivate_delay_us && spi->last_transaction_us) {
	delay_us = timer_get_us() - spi->last_transaction_us;
	if (delay_us < spi->ctrl->deactivate_delay_us) {
	debug("%s: delaying %lu uSec\n", __func__,
	spi->ctrl->deactivate_delay_us - delay_us);
	udelay(spi->ctrl->deactivate_delay_us - delay_us);
	}
	}
	clrbits_le32(&regs->command1, SPI_CMD1_CS_SW_VAL);
	}

	void tegra114_spi_cs_deactivate(struct spi_slave *slave)
	{
	struct tegra_spi_slave *spi = to_tegra_spi(slave);
	struct spi_regs *regs = spi->ctrl->regs;

	setbits_le32(&regs->command1, SPI_CMD1_CS_SW_VAL);

	/* Remember time of this transaction so we can honor the bus delay */
	if (spi->ctrl->deactivate_delay_us)
	spi->last_transaction_us = timer_get_us();

	debug("%s: deactivate_delay_us = %u, last_transaction_us = %lu\n",
	__func__, spi->ctrl->deactivate_delay_us,
	spi->last_transaction_us);
	}

	void spi_set_deactivate_delay_us(struct spi_slave *slave, int delay_us)
	{
	struct tegra_spi_slave *spi = to_tegra_spi(slave);

	spi->ctrl->deactivate_delay_us = delay_us;

	debug("%s: deactivate_delay_us set to %d\n",
	__func__, spi->ctrl->deactivate_delay_us);
	}

	static int spi_check_fifo_error(int fifo_status)
	{
	int ret = 0;

	if (fifo_status & SPI_FIFO_STS_ERR) {
	ret = fifo_status;
	debug("%s: got a fifo error: ", __func__);
	if (fifo_status & SPI_FIFO_STS_TX_FIFO_OVF)
	debug("tx FIFO overflow ");
	if (fifo_status & SPI_FIFO_STS_TX_FIFO_UNR)
	debug("tx FIFO underrun ");
	if (fifo_status & SPI_FIFO_STS_RX_FIFO_OVF)
	debug("rx FIFO overflow ");
	if (fifo_status & SPI_FIFO_STS_RX_FIFO_UNR)
	debug("rx FIFO underrun ");
	if (fifo_status & SPI_FIFO_STS_TX_FIFO_FULL)
	debug("tx FIFO full ");
	if (fifo_status & SPI_FIFO_STS_TX_FIFO_EMPTY)
	debug("tx FIFO empty ");
	if (fifo_status & SPI_FIFO_STS_RX_FIFO_FULL)
	debug("rx FIFO full ");
	if (fifo_status & SPI_FIFO_STS_RX_FIFO_EMPTY)
	debug("rx FIFO empty ");
	debug("\n");
	} else {
	/* no error, but fifo is still empty, set as an error */
	if (fifo_status & SPI_FIFO_STS_RX_FIFO_EMPTY) {
	ret = SPI_FIFO_STS_RX_FIFO_EMPTY;
	debug("%s: rx FIFO should not be empty\n", __func__);
	}
	}

	return ret;
	}

	/**
	* Output number of 'bytes' of data from dout to SPI interface.
	*
	* If out_bytes is 0 or if dout is NULL, data of 0 is output to SPI interface.
	*
	* @param regs pointer to SPI register structure
	* @param dout data is output from this pointer
	* @param bytes # of bytes to send, must be <= 4
	* @param out_bytes a counter to keep track # of bytes to output from dout;
	* will be updated by this routine if data are outputted
	* from dout
	* @return # of bytes are output from dout.
	*/
	static int spi_out_data(struct spi_regs regs, const u8 dout, int bytes,
	int *out_bytes)
	{
	int tmpdout;
	int dout_len;

	if (dout && (*out_bytes > 0)) {
	memcpy((void )&tmpdout, (void )dout, bytes);
	*out_bytes -= bytes;
	dout_len = bytes;
	} else {
	tmpdout = 0;
	dout_len = 0;
	}

	clrsetbits_le32(&regs->command1,
	SPI_CMD1_BIT_LEN_MASK << SPI_CMD1_BIT_LEN_SHIFT,
	(bytes * 8 - 1) << SPI_CMD1_BIT_LEN_SHIFT);
	writel(tmpdout, &regs->tx_fifo);
	setbits_le32(&regs->command1, SPI_CMD1_GO);

	return dout_len;
	}

	int tegra114_spi_xfer(struct spi_slave *slave, unsigned int bitlen,
	const void data_out, void data_in, unsigned long flags)
	{
	struct tegra_spi_slave *spi = to_tegra_spi(slave);
	struct spi_regs *regs = spi->ctrl->regs;
	u32 tmpdin = 0;
	const u8 *dout = data_out;
	u8 *din = data_in;
	int num_bytes, out_bytes;
	int ret;
	int found = 1;
	u32 max_timeout_ms = 0;
	u32 start_time = 0;
	unsigned header = slave->frame_header;

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

	if (slave->half_duplex) {
	found = 0;
	max_timeout_ms = slave->max_timeout_ms;
	if (max_timeout_ms == 0)
	max_timeout_ms = SPI_REPLY_TIMEOUT_MS;

	start_time = get_timer(0);
	}

	ret = 0;

	/* clear all error status bits */
	writel(readl(&regs->fifo_status), &regs->fifo_status);

	/* clear ready bit */
	setbits_le32(&regs->xfer_status, SPI_XFER_STS_RDY);

	clrsetbits_le32(&regs->command1,
	SPI_CMD1_LSBI_FE \| SPI_CMD1_LSBY_FE,
	SPI_CMD1_RX_EN \| SPI_CMD1_TX_EN \|
	(slave->cs << SPI_CMD1_CS_SEL_SHIFT));

	/* set xfer size to 1 block (32 bits) */
	writel(0, &regs->dma_blk);

	if (flags & SPI_XFER_BEGIN)
	spi_cs_activate(slave);

	/* handle data in 32-bit chunks */
	while (num_bytes > 0) {
	int bytes;
	int tm;
	u8 *pheader;
	u32 fifo_status, xfer_status;

	if (!found)
	if (get_timer(start_time) > max_timeout_ms) {
	printf("%s: did not get reply in %u ms\n",
	__func__, max_timeout_ms);
	ret = -EIO;
	break;
	}

	/* Send out data, 4 bytes a time */
	bytes = (num_bytes > 4) ? 4 : num_bytes;
	dout += spi_out_data(regs, dout, bytes, &out_bytes);

	/*
	* Wait for SPI transmit FIFO to empty, or to time out.
	* The RX FIFO status will be read and cleared last
	*/
	for (tm = 0; tm < SPI_TIMEOUT; ++tm) {
	xfer_status = readl(&regs->xfer_status);
	if (xfer_status & SPI_XFER_STS_RDY)
	break;
	}

	if (tm >= SPI_TIMEOUT) {
	debug("%s: timed out waiting for STS_RDY\n", __func__);
	ret = tm;
	break; /* break out of while (num_bytes > 0) loop */
	}

	/* clear RDY status */
	writel(SPI_XFER_STS_RDY, &regs->xfer_status);

	/* check if there is any FIFO error */
	fifo_status = readl(&regs->fifo_status);
	ret = spi_check_fifo_error(fifo_status);
	if (ret)
	/* break out of while loop if there is any fifo error */
	break;

	/* no error, read RX FIFO */
	tmpdin = readl(&regs->rx_fifo);

	/* process input package */
	if (din) {
	if (found) {
	memcpy(din, &tmpdin, bytes);
	din += bytes;
	} else {
	pheader = memchr(&tmpdin, header, bytes);
	if (pheader) {
	int len;

	found = 1;
	/* determine how many bytes to copy */
	len = pheader - (u8 *)&tmpdin;
	bytes -= (len + 1);
	memcpy(din, pheader + 1, bytes);
	din += bytes;
	} else {
	bytes = 0;
	}
	}
	}

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

	num_bytes -= bytes;
	}

	if (flags & SPI_XFER_END)
	spi_cs_deactivate(slave);

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

	return 0;
	}

	#ifdef CONFIG_OF_CONTROL
	/**
	* Get the SPI bus for an fdt node
	*
	* @param blob Device tree blob
	* @param spi_node cached pointer to the SPI interface this node belongs to
	* @return spi bus # if ok, -1 on error
	*/
	int spi_get_bus_by_node(const void *blob, unsigned spi_node)
	{
	int i;

	for (i = 0; i < ARRAY_SIZE(spi_ctrls); i++)
	if (spi_ctrls[i].node == spi_node)
	return i;
	return -1;
	}
	#endif