Patchwork [U-Boot,6/7] tegra: add SPI SLINK driver

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Submitter Allen Martin
Date Jan. 11, 2013, 6:44 p.m.
Message ID <1357929877-18671-7-git-send-email-amartin@nvidia.com>
Download mbox | patch
Permalink /patch/211403/
State Superseded
Headers show

Comments

Allen Martin - Jan. 11, 2013, 6:44 p.m.
Add driver for tegra SPI "SLINK" style driver.  This controller is
similar to the tegra20 SPI "SFLASH" controller.  The difference is
that the SLINK controller is a genernal purpose SPI controller and the
SFLASH controller is special purpose and can only talk to FLASH
devices.  In addition there are potentially many instances of an SLINK
controller on tegra and only a single instance of SFLASH.  Tegra20 is
currently ths only version of tegra that instantiates an SFLASH
controller.

This driver supports basic PIO mode of operation and is configurable
(CONFIG_OF_CONTROL) to be driven off devicetree bindings.  Up to 4
devices per controller may be attached, although typically only a
single chip select line is exposed from tegra per controller so in
reality this is usually limited to 1.

To enable this driver, use CONFIG_TEGRA_SLINK

Signed-off-by: Allen Martin <amartin@nvidia.com>
---
 arch/arm/include/asm/arch-tegra/tegra_slink.h |   84 +++++++
 board/nvidia/common/board.c                   |    3 +-
 drivers/spi/Makefile                          |    1 +
 drivers/spi/tegra_slink.c                     |  333 +++++++++++++++++++++++++
 4 files changed, 420 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm/include/asm/arch-tegra/tegra_slink.h
 create mode 100644 drivers/spi/tegra_slink.c
Stephen Warren - Jan. 12, 2013, 12:22 a.m.
On 01/11/2013 11:44 AM, Allen Martin wrote:
> Add driver for tegra SPI "SLINK" style driver.  This controller is
> similar to the tegra20 SPI "SFLASH" controller.  The difference is
> that the SLINK controller is a genernal purpose SPI controller and the
> SFLASH controller is special purpose and can only talk to FLASH
> devices.  In addition there are potentially many instances of an SLINK
> controller on tegra and only a single instance of SFLASH.  Tegra20 is
> currently ths only version of tegra that instantiates an SFLASH
> controller.
> 
> This driver supports basic PIO mode of operation and is configurable
> (CONFIG_OF_CONTROL) to be driven off devicetree bindings.  Up to 4
> devices per controller may be attached, although typically only a
> single chip select line is exposed from tegra per controller so in
> reality this is usually limited to 1.
> 
> To enable this driver, use CONFIG_TEGRA_SLINK

> diff --git a/drivers/spi/tegra_slink.c b/drivers/spi/tegra_slink.c

> +void spi_init(void)
> +{
> +	int node = 0, i;
> +	struct tegra_spi_ctrl *ctrl;
> +	for (i = 0; i < CONFIG_TEGRA_SLINK_CTRLS; i++) {
> +		ctrl = &spi_ctrls[i];
> +#ifdef CONFIG_OF_CONTROL

Is this ever false for Tegra upstream? I don't think so.

> +		node = fdtdec_next_compatible(gd->fdt_blob, node,
> +					      COMPAT_NVIDIA_TEGRA20_SLINK);
> +		if (!node)
> +			break;
> +		ctrl->regs = (struct slink_tegra *)fdtdec_get_addr(gd->fdt_blob,
> +								   node, "reg");
> +		if ((fdt_addr_t)ctrl->regs == FDT_ADDR_T_NONE) {
> +			debug("%s: no slink register found\n", __func__);
> +			break;

Shouldn't most of the "break"s in this loop be "continue"s, so that any
other nodes can be parsed? After all, this loop is trying to initialize
all SLINK controllers in the DT right?
Allen Martin - Jan. 12, 2013, 3:58 a.m.
On Fri, Jan 11, 2013 at 04:22:46PM -0800, Stephen Warren wrote:
> On 01/11/2013 11:44 AM, Allen Martin wrote:
> > Add driver for tegra SPI "SLINK" style driver.  This controller is
> > similar to the tegra20 SPI "SFLASH" controller.  The difference is
> > that the SLINK controller is a genernal purpose SPI controller and the
> > SFLASH controller is special purpose and can only talk to FLASH
> > devices.  In addition there are potentially many instances of an SLINK
> > controller on tegra and only a single instance of SFLASH.  Tegra20 is
> > currently ths only version of tegra that instantiates an SFLASH
> > controller.
> > 
> > This driver supports basic PIO mode of operation and is configurable
> > (CONFIG_OF_CONTROL) to be driven off devicetree bindings.  Up to 4
> > devices per controller may be attached, although typically only a
> > single chip select line is exposed from tegra per controller so in
> > reality this is usually limited to 1.
> > 
> > To enable this driver, use CONFIG_TEGRA_SLINK
> 
> > diff --git a/drivers/spi/tegra_slink.c b/drivers/spi/tegra_slink.c
> 
> > +void spi_init(void)
> > +{
> > +	int node = 0, i;
> > +	struct tegra_spi_ctrl *ctrl;
> > +	for (i = 0; i < CONFIG_TEGRA_SLINK_CTRLS; i++) {
> > +		ctrl = &spi_ctrls[i];
> > +#ifdef CONFIG_OF_CONTROL
> 
> Is this ever false for Tegra upstream? I don't think so.

No, but I think it's worthwhile to keep it under #ifdef so this driver
could be used from the SPL if the need ever comes up.  I tested by
forcing it off for this driver and it works.

> 
> > +		node = fdtdec_next_compatible(gd->fdt_blob, node,
> > +					      COMPAT_NVIDIA_TEGRA20_SLINK);
> > +		if (!node)
> > +			break;
> > +		ctrl->regs = (struct slink_tegra *)fdtdec_get_addr(gd->fdt_blob,
> > +								   node, "reg");
> > +		if ((fdt_addr_t)ctrl->regs == FDT_ADDR_T_NONE) {
> > +			debug("%s: no slink register found\n", __func__);
> > +			break;
> 
> Shouldn't most of the "break"s in this loop be "continue"s, so that any
> other nodes can be parsed? After all, this loop is trying to initialize
> all SLINK controllers in the DT right?

True, and looking at this code I think the driver is going to do
something bad if any of the controllers are not fully specified and
you go to use it later.  I think the controller structure needs a
"valid" flag.

-Allen

Patch

diff --git a/arch/arm/include/asm/arch-tegra/tegra_slink.h b/arch/arm/include/asm/arch-tegra/tegra_slink.h
new file mode 100644
index 0000000..74804b5
--- /dev/null
+++ b/arch/arm/include/asm/arch-tegra/tegra_slink.h
@@ -0,0 +1,84 @@ 
+/*
+ * NVIDIA Tegra SPI-SLINK controller
+ *
+ * Copyright 2010-2013 NVIDIA Corporation
+ *
+ * This software may be used and distributed according to the
+ * terms of the GNU Public License, Version 2, incorporated
+ * herein by reference.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * Version 2 as published by the Free Software Foundation.
+ *
+ * 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
+ */
+
+#ifndef _TEGRA_SLINK_H_
+#define _TEGRA_SLINK_H_
+
+#include <asm/types.h>
+
+struct slink_tegra {
+	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 */
+};
+
+/* COMMAND */
+#define SLINK_CMD_ENB			(1 << 31)
+#define SLINK_CMD_GO			(1 << 30)
+#define SLINK_CMD_M_S			(1 << 28)
+#define SLINK_CMD_CK_SDA		(1 << 21)
+#define SLINK_CMD_CS_POL		(1 << 13)
+#define SLINK_CMD_CS_VAL		(1 << 12)
+#define SLINK_CMD_CS_SOFT		(1 << 11)
+#define SLINK_CMD_BIT_LENGTH		(1 << 4)
+#define SLINK_CMD_BIT_LENGTH_MASK	0x0000001F
+/* COMMAND2 */
+#define SLINK_CMD2_TXEN			(1 << 30)
+#define SLINK_CMD2_RXEN			(1 << 31)
+#define SLINK_CMD2_SS_EN		(1 << 18)
+#define SLINK_CMD2_SS_EN_SHIFT		18
+#define SLINK_CMD2_SS_EN_MASK		0x000C0000
+#define SLINK_CMD2_CS_ACTIVE_BETWEEN	(1 << 17)
+/* STATUS */
+#define SLINK_STAT_BSY			(1 << 31)
+#define SLINK_STAT_RDY			(1 << 30)
+#define SLINK_STAT_ERR			(1 << 29)
+#define SLINK_STAT_RXF_FLUSH		(1 << 27)
+#define SLINK_STAT_TXF_FLUSH		(1 << 26)
+#define SLINK_STAT_RXF_OVF		(1 << 25)
+#define SLINK_STAT_TXF_UNR		(1 << 24)
+#define SLINK_STAT_RXF_EMPTY		(1 << 23)
+#define SLINK_STAT_RXF_FULL		(1 << 22)
+#define SLINK_STAT_TXF_EMPTY		(1 << 21)
+#define SLINK_STAT_TXF_FULL		(1 << 20)
+#define SLINK_STAT_TXF_OVF		(1 << 19)
+#define SLINK_STAT_RXF_UNR		(1 << 18)
+#define SLINK_STAT_CUR_BLKCNT		(1 << 15)
+/* STATUS2 */
+#define SLINK_STAT2_RXF_FULL_CNT	(1 << 16)
+#define SLINK_STAT2_TXF_FULL_CNT	(1 << 0)
+
+#define SPI_TIMEOUT		1000
+#define TEGRA_SPI_MAX_FREQ	52000000
+
+#endif	/* _TEGRA_SLINK_H_ */
diff --git a/board/nvidia/common/board.c b/board/nvidia/common/board.c
index a4af539..63a7fcb 100644
--- a/board/nvidia/common/board.c
+++ b/board/nvidia/common/board.c
@@ -131,10 +131,11 @@  int board_init(void)
 #ifdef CONFIG_SPI_UART_SWITCH
 	gpio_config_uart();
 #endif
-#ifdef CONFIG_TEGRA_SPI
+#if defined(CONFIG_TEGRA_SPI) || defined(CONFIG_TEGRA_SLINK)
 	pin_mux_spi();
 	spi_init();
 #endif
+
 #ifdef CONFIG_PWM_TEGRA
 	if (pwm_init(gd->fdt_blob))
 		debug("%s: Failed to init pwm\n", __func__);
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 824d357..83abcbd 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -46,6 +46,7 @@  COBJS-$(CONFIG_SOFT_SPI) += soft_spi.o
 COBJS-$(CONFIG_SH_SPI) += sh_spi.o
 COBJS-$(CONFIG_FSL_ESPI) += fsl_espi.o
 COBJS-$(CONFIG_TEGRA_SPI) += tegra_spi.o
+COBJS-$(CONFIG_TEGRA_SLINK) += tegra_slink.o
 COBJS-$(CONFIG_XILINX_SPI) += xilinx_spi.o
 
 COBJS	:= $(COBJS-y)
diff --git a/drivers/spi/tegra_slink.c b/drivers/spi/tegra_slink.c
new file mode 100644
index 0000000..83c1cc9
--- /dev/null
+++ b/drivers/spi/tegra_slink.c
@@ -0,0 +1,333 @@ 
+/*
+ * NVIDIA Tegra SPI-SLINK controller
+ *
+ * Copyright (c) 2010-2013 NVIDIA Corporation
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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.
+ *
+ * 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/gpio.h>
+#include <asm/arch/clock.h>
+#include <asm/arch-tegra/clk_rst.h>
+#include <asm/arch-tegra/tegra_slink.h>
+#include <spi.h>
+#ifdef CONFIG_OF_CONTROL
+#include <fdtdec.h>
+#endif
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct tegra_spi_ctrl {
+	struct slink_tegra *regs;
+	unsigned int freq;
+	unsigned int mode;
+	int periph_id;
+};
+
+struct tegra_spi_slave {
+	struct spi_slave slave;
+	struct tegra_spi_ctrl *ctrl;
+};
+
+static struct tegra_spi_ctrl spi_ctrls[CONFIG_TEGRA_SLINK_CTRLS];
+
+static inline struct tegra_spi_slave *to_tegra_spi(struct spi_slave *slave)
+{
+	return container_of(slave, struct tegra_spi_slave, slave);
+}
+
+int spi_cs_is_valid(unsigned int bus, unsigned int cs)
+{
+	if (bus >= CONFIG_TEGRA_SLINK_CTRLS || cs > 3)
+		return 0;
+	else
+		return 1;
+}
+
+struct spi_slave *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 = malloc(sizeof(struct tegra_spi_slave));
+	if (!spi) {
+		printf("SPI error: malloc of SPI structure failed\n");
+		return NULL;
+	}
+	spi->slave.bus = bus;
+	spi->slave.cs = cs;
+	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;
+
+	return &spi->slave;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+	struct tegra_spi_slave *spi = to_tegra_spi(slave);
+
+	free(spi);
+}
+
+void spi_init(void)
+{
+	int node = 0, i;
+	struct tegra_spi_ctrl *ctrl;
+	for (i = 0; i < CONFIG_TEGRA_SLINK_CTRLS; i++) {
+		ctrl = &spi_ctrls[i];
+#ifdef CONFIG_OF_CONTROL
+		node = fdtdec_next_compatible(gd->fdt_blob, node,
+					      COMPAT_NVIDIA_TEGRA20_SLINK);
+		if (!node)
+			break;
+		ctrl->regs = (struct slink_tegra *)fdtdec_get_addr(gd->fdt_blob,
+								   node, "reg");
+		if ((fdt_addr_t)ctrl->regs == FDT_ADDR_T_NONE) {
+			debug("%s: no slink register found\n", __func__);
+			break;
+		}
+		ctrl->freq = fdtdec_get_int(gd->fdt_blob, node,
+					    "spi-max-frequency", 0);
+		if (!ctrl->freq) {
+			debug("%s: no slink max frequency found\n", __func__);
+			break;
+		}
+
+		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__);
+			break;
+		}
+#else
+		u32 base_regs[] = {
+			NV_PA_SLINK1_BASE,
+			NV_PA_SLINK2_BASE,
+			NV_PA_SLINK3_BASE,
+			NV_PA_SLINK4_BASE,
+			NV_PA_SLINK5_BASE,
+			NV_PA_SLINK6_BASE,
+		};
+		int periph_ids[] = {
+			PERIPH_ID_SBC1,
+			PERIPH_ID_SBC2,
+			PERIPH_ID_SBC3,
+			PERIPH_ID_SBC4,
+			PERIPH_ID_SBC5,
+			PERIPH_ID_SBC6,
+		}
+		ctrl->regs = (struct slink_tegra *)base_regs[i];
+		ctrl->freq = TEGRA_SPI_MAX_FREQ;
+		ctrl->periph_id = periph_ids[i];
+#endif
+
+		debug("%s: found controller at %p, freq = %u, periph_id = %d\n",
+		      __func__, ctrl->regs, ctrl->freq, ctrl->periph_id);
+	}
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+	struct tegra_spi_slave *spi = to_tegra_spi(slave);
+	struct slink_tegra *regs = spi->ctrl->regs;
+	u32 reg;
+
+	/* Change SPI clock to correct frequency, PLLP_OUT0 source */
+	clock_start_periph_pll(spi->ctrl->periph_id, CLOCK_ID_PERIPH,
+			       spi->ctrl->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;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+}
+
+void spi_cs_activate(struct spi_slave *slave)
+{
+	struct tegra_spi_slave *spi = to_tegra_spi(slave);
+	struct slink_tegra *regs = spi->ctrl->regs;
+
+	/* CS is negated on Tegra, so drive a 1 to get a 0 */
+	setbits_le32(&regs->command, SLINK_CMD_CS_VAL);
+}
+
+void spi_cs_deactivate(struct spi_slave *slave)
+{
+	struct tegra_spi_slave *spi = to_tegra_spi(slave);
+	struct slink_tegra *regs = spi->ctrl->regs;
+
+	/* CS is negated on Tegra, so drive a 0 to get a 1 */
+	clrbits_le32(&regs->command, SLINK_CMD_CS_VAL);
+}
+
+int 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 slink_tegra *regs = spi->ctrl->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__, slave->bus, slave->cs, 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));
+
+	reg = readl(&regs->command2);
+	reg |= SLINK_CMD2_TXEN | SLINK_CMD2_RXEN |
+		(slave->cs << SLINK_CMD2_SS_EN_SHIFT);
+	writel(reg, &regs->command2);
+	debug("%s entry: COMMAND2 = %08x\n", __func__, reg);
+
+	if (flags & SPI_XFER_BEGIN)
+		spi_cs_activate(slave);
+
+	/* 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];
+		}
+
+		num_bytes -= bytes;
+		if (dout)
+			dout += 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(slave);
+
+	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;
+}