diff mbox

SPI: DaVinci: Adding SPI driver for DM3xx/DM6467/DA8xx

Message ID 1247846498-23581-1-git-send-email-s-paulraj@ti.com (mailing list archive)
State Superseded
Headers show

Commit Message

s-paulraj@ti.com July 17, 2009, 4:01 p.m. UTC
From: Sandeep Paulraj <s-paulraj@ti.com>

The patch adds support for SPI in DaVinci
DM355/DM365/DM6467 and DA8xx.

This has been tested on the DM355, DM365 and DM6467 EVMs using
the EEPROM connected to SPI0

Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>
---
 arch/arm/mach-davinci/include/mach/spi.h |   45 ++
 drivers/spi/Kconfig                      |    7 +
 drivers/spi/Makefile                     |    1 +
 drivers/spi/davinci_spi.c                |  743 ++++++++++++++++++++++++++++++
 drivers/spi/davinci_spi.h                |  163 +++++++
 5 files changed, 959 insertions(+), 0 deletions(-)
 create mode 100644 arch/arm/mach-davinci/include/mach/spi.h
 create mode 100644 drivers/spi/davinci_spi.c
 create mode 100644 drivers/spi/davinci_spi.h

Comments

David Brownell July 17, 2009, 4:44 p.m. UTC | #1
You goofed on the changes to spi_setup() ... 

On Friday 17 July 2009, s-paulraj@ti.com wrote:
> +static int davinci_spi_setup(struct spi_device *spi)
> +{
> +       int retval;
> +       int op_mode = 0;
> +       struct davinci_spi *davinci_spi;
> +
> +       davinci_spi = spi_master_get_devdata(spi->master);
> +
> +       /*
> +        * Set up device-specific SPI configuration parameters.
> +        * Most of these would normally be handled in spi_setup(),

... by just moving all of the old davinci_spi_bufs_prep() here.

Example, that comment is specific to the old davinci_spi_bufs_prep()
code not this version.  That's an easy fix (although I'd still
rather see this have a single read and write to the FMT register).

Except the global options (loopback, READY handsdhaking) should
not be here ... in this hardware they are global, so that by
setting them here you could trash an ongoing transfer.

The rule of thumb for the setup() methods is that you must expect
they are called in the middle of a transfer for some *OTHER* chip
select line.  See 6e538aaf50ae782a890cbc02c27950448d8193e1 ...


> +        * updating the per-chipselect FMT registers, but some of
> +        * them use global controls like SPI_LOOP and SPI_READY.
> +        */
> +
> +       if (spi->mode & SPI_LSB_FIRST)
> +               set_fmt_bits(davinci_spi->base, SPIFMT_SHIFTDIR_MASK,
> +                               spi->chip_select);
> +       else
> +               clear_fmt_bits(davinci_spi->base, SPIFMT_SHIFTDIR_MASK,
> +                               spi->chip_select);
> +
> +       if (spi->mode & SPI_CPOL)
> +               set_fmt_bits(davinci_spi->base, SPIFMT_POLARITY_MASK,
> +                               spi->chip_select);
> +       else
> +               clear_fmt_bits(davinci_spi->base, SPIFMT_POLARITY_MASK,
> +                               spi->chip_select);
> +
> +       if (!(spi->mode & SPI_CPHA))
> +               set_fmt_bits(davinci_spi->base, SPIFMT_PHASE_MASK,
> +                               spi->chip_select);
> +       else
> +               clear_fmt_bits(davinci_spi->base, SPIFMT_PHASE_MASK,
> +                               spi->chip_select);
> +
> +       if (davinci_spi->version == SPI_VERSION_2) {
> +               clear_fmt_bits(davinci_spi->base, SPIFMT_WDELAY_MASK,
> +                               spi->chip_select);
> +               set_fmt_bits(davinci_spi->base,
> +                               (davinci_spi->pdata->wdelay
> +                                               << SPIFMT_WDELAY_SHIFT)
> +                                       & SPIFMT_WDELAY_MASK,
> +                               spi->chip_select);
> +
> +               if (davinci_spi->pdata->odd_parity)
> +                       set_fmt_bits(davinci_spi->base,
> +                                       SPIFMT_ODD_PARITY_MASK,
> +                                       spi->chip_select);
> +               else
> +                       clear_fmt_bits(davinci_spi->base,
> +                                       SPIFMT_ODD_PARITY_MASK,
> +                                       spi->chip_select);
> +
> +               if (davinci_spi->pdata->parity_enable)
> +                       set_fmt_bits(davinci_spi->base,
> +                                       SPIFMT_PARITYENA_MASK,
> +                                       spi->chip_select);
> +               else
> +                       clear_fmt_bits(davinci_spi->base,
> +                                       SPIFMT_PARITYENA_MASK,
> +                                       spi->chip_select);
> +
> +               if (davinci_spi->pdata->wait_enable)
> +                       set_fmt_bits(davinci_spi->base,
> +                                       SPIFMT_WAITENA_MASK,
> +                                       spi->chip_select);
> +               else
> +                       clear_fmt_bits(davinci_spi->base,
> +                                       SPIFMT_WAITENA_MASK,
> +                                       spi->chip_select);
> +
> +               if (davinci_spi->pdata->timer_disable)
> +                       set_fmt_bits(davinci_spi->base,
> +                                       SPIFMT_DISTIMER_MASK,
> +                                       spi->chip_select);
> +               else
> +                       clear_fmt_bits(davinci_spi->base,
> +                                       SPIFMT_DISTIMER_MASK,
> +                                       spi->chip_select);
> +       }

All those *_fmt_bits() ops are OK; the FMT register is specific to
a given chipselect line.  And you can trust that *THIS* chipselect
is not in use when this method is called.


> +
> +       /* Clock internal */
> +       if (davinci_spi->pdata->clk_internal)
> +               set_io_bits(davinci_spi->base + SPIGCR1,
> +                               SPIGCR1_CLKMOD_MASK);
> +       else
> +               clear_io_bits(davinci_spi->base + SPIGCR1,
> +                               SPIGCR1_CLKMOD_MASK);
> +
> +       /* master mode default */
> +       set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_MASTER_MASK);
> +
> +       if (davinci_spi->pdata->intr_level)
> +               iowrite32(SPI_INTLVL_1, davinci_spi->base + SPILVL);
> +       else
> +               iowrite32(SPI_INTLVL_0, davinci_spi->base + SPILVL);

But the *_io_bits() calls can crap on a pending transfer for some
other chipselect ... and the interrupt config bit should be done
in the probe(), since it never changes.  In fact all three of
those chunks seem like they should be in probe().


> +
> +       /*
> +        * Version 1 hardware supports two basic SPI modes:
> +        *  - Standard SPI mode uses 4 pins, with chipselect
> +        *  - 3 pin SPI is a 4 pin variant without CS (SPI_NO_CS)
> +        *      (distinct from SPI_3WIRE, with just one data wire;
> +        *      or similar variants without MOSI or without MISO)
> +        *
> +        * Version 2 hardware supports an optional handshaking signal,
> +        * so it can support two more modes:
> +        *  - 5 pin SPI variant is standard SPI plus SPI_READY
> +        *  - 4 pin with enable is (SPI_READY | SPI_NO_CS)
> +        */
> +
> +       op_mode = SPIPC0_DIFUN_MASK
> +               | SPIPC0_DOFUN_MASK
> +               | SPIPC0_CLKFUN_MASK;
> +       if (!(spi->mode & SPI_NO_CS))
> +               op_mode |= 1 << spi->chip_select;
> +       if (spi->mode & SPI_READY)
> +               op_mode |= SPIPC0_SPIENA_MASK;
> +
> +       iowrite32(op_mode, davinci_spi->base + SPIPC0);
> +
> +       if (spi->mode & SPI_LOOP)
> +               set_io_bits(davinci_spi->base + SPIGCR1,
> +                               SPIGCR1_LOOPBACK_MASK);
> +       else
> +               clear_io_bits(davinci_spi->base + SPIGCR1,
> +                               SPIGCR1_LOOPBACK_MASK);

These are all global.  I suggest moving this code so it kicks
in immediately before a message is processed for that
particular device.


> +
> +       /* if bits per word length is zero then set it default 8 */
> +       if (!spi->bits_per_word)
> +               spi->bits_per_word = 8;
> +
> +       /*
> +        * SPI in DaVinci and DA8xx operate between
> +        * 600 KHz and 50 MHz
> +        */
> +       if (spi->max_speed_hz < 600000 || spi->max_speed_hz > 50000000)
> +               return -EINVAL;
> +
> +       retval = davinci_spi_setup_transfer(spi, NULL);
> +
> +       return retval;
> +}
> +
diff mbox

Patch

diff --git a/arch/arm/mach-davinci/include/mach/spi.h b/arch/arm/mach-davinci/include/mach/spi.h
new file mode 100644
index 0000000..ff021e5
--- /dev/null
+++ b/arch/arm/mach-davinci/include/mach/spi.h
@@ -0,0 +1,45 @@ 
+/*
+ * Copyright 2009 Texas Instruments.
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef __ARCH_ARM_DAVINCI_SPI_H
+#define __ARCH_ARM_DAVINCI_SPI_H
+
+#define SPI_INTERN_CS	0xFF
+
+enum {
+	SPI_VERSION_1, /* For DM355/DM365/DM6467*/
+	SPI_VERSION_2, /* For DA8xx */
+};
+
+struct davinci_spi_platform_data {
+	u8	version;
+	u16	num_chipselect;
+	u32	wdelay;
+	u32	odd_parity;
+	u32	parity_enable;
+	u32	wait_enable;
+	u32	timer_disable;
+	u32	clk_internal;
+	u32	cs_hold;
+	u32	intr_level;
+	u32	poll_mode;
+	u8	c2tdelay;
+	u8	t2cdelay;
+};
+
+#endif	/* __ARCH_ARM_DAVINCI_SPI_H */
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 2c733c2..7fe9211 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -77,6 +77,13 @@  config SPI_AU1550
 	  This driver can also be built as a module.  If so, the module
 	  will be called au1550_spi.
 
+config SPI_DAVINCI
+	tristate "SPI controller driver for DaVinci/DA8xx SoC's"
+	depends on SPI_MASTER && ARCH_DAVINCI
+	select SPI_BITBANG
+	help
+	  SPI master controller for DaVinci and DA8xx SPI modules.
+
 config SPI_BITBANG
 	tristate "Utilities for Bitbanging SPI masters"
 	help
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 3de408d..910ac6d 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -31,6 +31,7 @@  obj-$(CONFIG_SPI_S3C24XX)		+= spi_s3c24xx.o
 obj-$(CONFIG_SPI_TXX9)			+= spi_txx9.o
 obj-$(CONFIG_SPI_XILINX)		+= xilinx_spi.o
 obj-$(CONFIG_SPI_SH_SCI)		+= spi_sh_sci.o
+obj-$(CONFIG_SPI_DAVINCI)		+= davinci_spi.o
 # 	... add above this line ...
 
 # SPI protocol drivers (device/link on bus)
diff --git a/drivers/spi/davinci_spi.c b/drivers/spi/davinci_spi.c
new file mode 100644
index 0000000..bed3b5e
--- /dev/null
+++ b/drivers/spi/davinci_spi.c
@@ -0,0 +1,743 @@ 
+/*
+ * Copyright (C) 2009 Texas Instruments.
+ *
+ * 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 <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+
+#include <mach/spi.h>
+
+#include "davinci_spi.h"
+
+
+static void davinci_spi_rx_buf_u8(u32 data, struct davinci_spi *davinci_spi)
+{
+	u8 *rx = davinci_spi->rx;
+
+	*rx++ = (u8)data;
+	davinci_spi->rx = rx;
+}
+
+static void davinci_spi_rx_buf_u16(u32 data, struct davinci_spi *davinci_spi)
+{
+	u16 *rx = davinci_spi->rx;
+
+	*rx++ = (u16)data;
+	davinci_spi->rx = rx;
+}
+
+static u32 davinci_spi_tx_buf_u8(struct davinci_spi *davinci_spi)
+{
+	u32 data;
+	const u8 *tx = davinci_spi->tx;
+
+	data = *tx++;
+	davinci_spi->tx = tx;
+	return data;
+}
+
+static u32 davinci_spi_tx_buf_u16(struct davinci_spi *davinci_spi)
+{
+	u32 data;
+	const u16 *tx = davinci_spi->tx;
+
+	data = *tx++;
+	davinci_spi->tx = tx;
+	return data;
+}
+
+static inline void set_io_bits(void __iomem *addr, u32 bits)
+{
+	u32 v = ioread32(addr);
+
+	v |= bits;
+	iowrite32(v, addr);
+}
+
+static inline void clear_io_bits(void __iomem *addr, u32 bits)
+{
+	u32 v = ioread32(addr);
+
+	v &= ~bits;
+	iowrite32(v, addr);
+}
+
+static inline void set_fmt_bits(void __iomem *addr, u32 bits, int cs_num)
+{
+	set_io_bits(addr + SPIFMT0 + (0x4 * cs_num), bits);
+}
+
+static inline void clear_fmt_bits(void __iomem *addr, u32 bits, int cs_num)
+{
+	clear_io_bits(addr + SPIFMT0 + (0x4 * cs_num), bits);
+}
+
+/*
+ * Interface to control the chip select signal
+ */
+static void davinci_spi_chipselect(struct spi_device *spi, int value)
+{
+	struct davinci_spi *davinci_spi;
+	struct davinci_spi_platform_data *pdata;
+	u32 data1_reg_val = 0;
+
+	davinci_spi = spi_master_get_devdata(spi->master);
+	pdata = davinci_spi->pdata;
+
+	/*
+	 * Board specific chip select logic decides the polarity and cs
+	 * line for the controller
+	 */
+	if (value == BITBANG_CS_INACTIVE) {
+		set_io_bits(davinci_spi->base + SPIDEF, CS_DEFAULT);
+
+		data1_reg_val |= CS_DEFAULT << SPIDAT1_CSNR_SHIFT;
+		iowrite32(data1_reg_val, davinci_spi->base + SPIDAT1);
+
+		while ((ioread32(davinci_spi->base + SPIBUF)
+					& SPIBUF_RXEMPTY_MASK) == 0)
+			cpu_relax();
+	}
+}
+
+/*
+ * davinci_spi_setup_transfer - This functions will determine transfer method
+ * @spi: spi device on which data transfer to be done
+ * @t: spi transfer in which transfer info is filled
+ *
+ * This function determines data transfer method (8/16/32 bit transfer).
+ * It will also set the SPI Clock Control register according to
+ * SPI slave device freq.
+ */
+static int davinci_spi_setup_transfer(struct spi_device *spi,
+		struct spi_transfer *t)
+{
+
+	struct davinci_spi *davinci_spi;
+	struct davinci_spi_platform_data *pdata;
+	u8 bits_per_word = 0;
+	u32 hz = 0, prescale;
+
+	davinci_spi = spi_master_get_devdata(spi->master);
+	pdata = davinci_spi->pdata;
+
+	if (t) {
+		bits_per_word = t->bits_per_word;
+		hz = t->speed_hz;
+	}
+
+	/* if bits_per_word is not set then set it default */
+	if (!bits_per_word)
+		bits_per_word = spi->bits_per_word;
+
+	/*
+	 * Assign function pointer to appropriate transfer method
+	 * 8bit, 16bit or 32bit transfer
+	 */
+	if (bits_per_word <= 8 && bits_per_word >= 2) {
+		davinci_spi->get_rx = davinci_spi_rx_buf_u8;
+		davinci_spi->get_tx = davinci_spi_tx_buf_u8;
+		davinci_spi->slave[spi->chip_select].bytes_per_word = 1;
+	} else if (bits_per_word <= 16 && bits_per_word >= 2) {
+		davinci_spi->get_rx = davinci_spi_rx_buf_u16;
+		davinci_spi->get_tx = davinci_spi_tx_buf_u16;
+		davinci_spi->slave[spi->chip_select].bytes_per_word = 2;
+	} else
+		return -EINVAL;
+
+	if (!hz)
+		hz = spi->max_speed_hz;
+
+	clear_fmt_bits(davinci_spi->base, SPIFMT_CHARLEN_MASK,
+			spi->chip_select);
+	set_fmt_bits(davinci_spi->base, bits_per_word & 0x1f,
+			spi->chip_select);
+
+	prescale = ((clk_get_rate(davinci_spi->clk) / hz) - 1) & 0xff;
+
+	clear_fmt_bits(davinci_spi->base, 0x0000ff00, spi->chip_select);
+	set_fmt_bits(davinci_spi->base, prescale << 8, spi->chip_select);
+
+	return 0;
+}
+
+/*
+ * davinci_spi_setup - This functions will set default transfer method
+ * @spi: spi device on which data transfer to be done
+ *
+ * This functions sets the default transfer method.
+ */
+
+static int davinci_spi_setup(struct spi_device *spi)
+{
+	int retval;
+	int op_mode = 0;
+	struct davinci_spi *davinci_spi;
+
+	davinci_spi = spi_master_get_devdata(spi->master);
+
+	/*
+	 * Set up device-specific SPI configuration parameters.
+	 * Most of these would normally be handled in spi_setup(),
+	 * updating the per-chipselect FMT registers, but some of
+	 * them use global controls like SPI_LOOP and SPI_READY.
+	 */
+
+	if (spi->mode & SPI_LSB_FIRST)
+		set_fmt_bits(davinci_spi->base, SPIFMT_SHIFTDIR_MASK,
+				spi->chip_select);
+	else
+		clear_fmt_bits(davinci_spi->base, SPIFMT_SHIFTDIR_MASK,
+				spi->chip_select);
+
+	if (spi->mode & SPI_CPOL)
+		set_fmt_bits(davinci_spi->base, SPIFMT_POLARITY_MASK,
+				spi->chip_select);
+	else
+		clear_fmt_bits(davinci_spi->base, SPIFMT_POLARITY_MASK,
+				spi->chip_select);
+
+	if (!(spi->mode & SPI_CPHA))
+		set_fmt_bits(davinci_spi->base, SPIFMT_PHASE_MASK,
+				spi->chip_select);
+	else
+		clear_fmt_bits(davinci_spi->base, SPIFMT_PHASE_MASK,
+				spi->chip_select);
+
+	if (davinci_spi->version == SPI_VERSION_2) {
+		clear_fmt_bits(davinci_spi->base, SPIFMT_WDELAY_MASK,
+				spi->chip_select);
+		set_fmt_bits(davinci_spi->base,
+				(davinci_spi->pdata->wdelay
+						<< SPIFMT_WDELAY_SHIFT)
+					& SPIFMT_WDELAY_MASK,
+				spi->chip_select);
+
+		if (davinci_spi->pdata->odd_parity)
+			set_fmt_bits(davinci_spi->base,
+					SPIFMT_ODD_PARITY_MASK,
+					spi->chip_select);
+		else
+			clear_fmt_bits(davinci_spi->base,
+					SPIFMT_ODD_PARITY_MASK,
+					spi->chip_select);
+
+		if (davinci_spi->pdata->parity_enable)
+			set_fmt_bits(davinci_spi->base,
+					SPIFMT_PARITYENA_MASK,
+					spi->chip_select);
+		else
+			clear_fmt_bits(davinci_spi->base,
+					SPIFMT_PARITYENA_MASK,
+					spi->chip_select);
+
+		if (davinci_spi->pdata->wait_enable)
+			set_fmt_bits(davinci_spi->base,
+					SPIFMT_WAITENA_MASK,
+					spi->chip_select);
+		else
+			clear_fmt_bits(davinci_spi->base,
+					SPIFMT_WAITENA_MASK,
+					spi->chip_select);
+
+		if (davinci_spi->pdata->timer_disable)
+			set_fmt_bits(davinci_spi->base,
+					SPIFMT_DISTIMER_MASK,
+					spi->chip_select);
+		else
+			clear_fmt_bits(davinci_spi->base,
+					SPIFMT_DISTIMER_MASK,
+					spi->chip_select);
+	}
+
+	/* Clock internal */
+	if (davinci_spi->pdata->clk_internal)
+		set_io_bits(davinci_spi->base + SPIGCR1,
+				SPIGCR1_CLKMOD_MASK);
+	else
+		clear_io_bits(davinci_spi->base + SPIGCR1,
+				SPIGCR1_CLKMOD_MASK);
+
+	/* master mode default */
+	set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_MASTER_MASK);
+
+	if (davinci_spi->pdata->intr_level)
+		iowrite32(SPI_INTLVL_1, davinci_spi->base + SPILVL);
+	else
+		iowrite32(SPI_INTLVL_0, davinci_spi->base + SPILVL);
+
+	/*
+	 * Version 1 hardware supports two basic SPI modes:
+	 *  - Standard SPI mode uses 4 pins, with chipselect
+	 *  - 3 pin SPI is a 4 pin variant without CS (SPI_NO_CS)
+	 *	(distinct from SPI_3WIRE, with just one data wire;
+	 *	or similar variants without MOSI or without MISO)
+	 *
+	 * Version 2 hardware supports an optional handshaking signal,
+	 * so it can support two more modes:
+	 *  - 5 pin SPI variant is standard SPI plus SPI_READY
+	 *  - 4 pin with enable is (SPI_READY | SPI_NO_CS)
+	 */
+
+	op_mode = SPIPC0_DIFUN_MASK
+		| SPIPC0_DOFUN_MASK
+		| SPIPC0_CLKFUN_MASK;
+	if (!(spi->mode & SPI_NO_CS))
+		op_mode |= 1 << spi->chip_select;
+	if (spi->mode & SPI_READY)
+		op_mode |= SPIPC0_SPIENA_MASK;
+
+	iowrite32(op_mode, davinci_spi->base + SPIPC0);
+
+	if (spi->mode & SPI_LOOP)
+		set_io_bits(davinci_spi->base + SPIGCR1,
+				SPIGCR1_LOOPBACK_MASK);
+	else
+		clear_io_bits(davinci_spi->base + SPIGCR1,
+				SPIGCR1_LOOPBACK_MASK);
+
+	/* if bits per word length is zero then set it default 8 */
+	if (!spi->bits_per_word)
+		spi->bits_per_word = 8;
+
+	/*
+	 * SPI in DaVinci and DA8xx operate between
+	 * 600 KHz and 50 MHz
+	 */
+	if (spi->max_speed_hz < 600000 || spi->max_speed_hz > 50000000)
+		return -EINVAL;
+
+	retval = davinci_spi_setup_transfer(spi, NULL);
+
+	return retval;
+}
+
+static int davinci_spi_check_error(struct davinci_spi *davinci_spi,
+				   int int_status)
+{
+	struct device *sdev = davinci_spi->bitbang.master->dev.parent;
+
+	if (int_status & SPIFLG_TIMEOUT_MASK) {
+		dev_dbg(sdev, "SPI Time-out Error\n");
+		return -ETIMEDOUT;
+	}
+	if (int_status & SPIFLG_DESYNC_MASK) {
+		dev_dbg(sdev, "SPI Desynchronization Error\n");
+		return -EIO;
+	}
+	if (int_status & SPIFLG_BITERR_MASK) {
+		dev_dbg(sdev, "SPI Bit error\n");
+		return -EIO;
+	}
+
+	if (davinci_spi->version == SPI_VERSION_2) {
+		if (int_status & SPIFLG_DLEN_ERR_MASK) {
+			dev_dbg(sdev, "SPI Data Length Error\n");
+			return -EIO;
+		}
+		if (int_status & SPIFLG_PARERR_MASK) {
+			dev_dbg(sdev, "SPI Parity Error\n");
+			return -EIO;
+		}
+		if (int_status & SPIFLG_OVRRUN_MASK) {
+			dev_dbg(sdev, "SPI Data Overrun error\n");
+			return -EIO;
+		}
+		if (int_status & SPIFLG_TX_INTR_MASK) {
+			dev_dbg(sdev, "SPI TX intr bit set\n");
+			return -EIO;
+		}
+		if (int_status & SPIFLG_BUF_INIT_ACTIVE_MASK) {
+			dev_dbg(sdev, "SPI Buffer Init Active\n");
+			return -EBUSY;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * davinci_spi_bufs - functions which will handle transfer data
+ * @spi: spi device on which data transfer to be done
+ * @t: spi transfer in which transfer info is filled
+ *
+ * This function will put data to be transferred into data register
+ * of SPI controller and then wait untill the completion will be marked
+ * by the IRQ Handler.
+ */
+static int davinci_spi_bufs_pio(struct spi_device *spi, struct spi_transfer *t)
+{
+	struct davinci_spi *davinci_spi;
+	int int_status, count, ret;
+	u8 conv, tmp;
+	u32 tx_data, data1_reg_val;
+	u32 buf_val, flg_val;
+	struct davinci_spi_platform_data *pdata;
+
+	davinci_spi = spi_master_get_devdata(spi->master);
+	pdata = davinci_spi->pdata;
+
+	davinci_spi->tx = t->tx_buf;
+	davinci_spi->rx = t->rx_buf;
+
+	/* convert len to words bbased on bits_per_word */
+	conv = davinci_spi->slave[spi->chip_select].bytes_per_word;
+	davinci_spi->count = t->len / conv;
+
+	INIT_COMPLETION(davinci_spi->done);
+
+	/* Enable SPI */
+	set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_SPIENA_MASK);
+
+	iowrite32(0 | (pdata->c2tdelay << SPI_C2TDELAY_SHIFT) |
+			(pdata->t2cdelay << SPI_T2CDELAY_SHIFT),
+			davinci_spi->base + SPIDELAY);
+
+	count = davinci_spi->count;
+	data1_reg_val = pdata->cs_hold << SPIDAT1_CSHOLD_SHIFT;
+	tmp = ~(0x1 << spi->chip_select);
+
+	clear_io_bits(davinci_spi->base + SPIDEF, ~tmp);
+
+	data1_reg_val |= tmp << SPIDAT1_CSNR_SHIFT;
+
+	while ((ioread32(davinci_spi->base + SPIBUF)
+				& SPIBUF_RXEMPTY_MASK) == 0)
+		cpu_relax();
+
+	/* Determine the command to execute READ or WRITE */
+	if (t->tx_buf) {
+		clear_io_bits(davinci_spi->base + SPIINT, SPIINT_MASKALL);
+
+		while (1) {
+			tx_data = davinci_spi->get_tx(davinci_spi);
+
+			data1_reg_val &= ~(0xFFFF);
+			data1_reg_val |= (0xFFFF & tx_data);
+
+			buf_val = ioread32(davinci_spi->base + SPIBUF);
+			if ((buf_val & SPIBUF_TXFULL_MASK) == 0) {
+				iowrite32(data1_reg_val,
+						davinci_spi->base + SPIDAT1);
+
+				count--;
+			}
+			while (ioread32(davinci_spi->base + SPIBUF)
+					& SPIBUF_RXEMPTY_MASK)
+				cpu_relax();
+
+			/* getting the returned byte */
+			if (t->rx_buf) {
+				buf_val = ioread32(davinci_spi->base + SPIBUF);
+				davinci_spi->get_rx(buf_val, davinci_spi);
+			}
+			if (count <= 0)
+				break;
+		}
+	} else {
+		if (pdata->poll_mode) {
+			while (1) {
+				/* keeps the serial clock going */
+				if ((ioread32(davinci_spi->base + SPIBUF)
+						& SPIBUF_TXFULL_MASK) == 0)
+					iowrite32(data1_reg_val,
+						davinci_spi->base + SPIDAT1);
+
+				while (ioread32(davinci_spi->base + SPIBUF) &
+						SPIBUF_RXEMPTY_MASK)
+					cpu_relax();
+
+				flg_val = ioread32(davinci_spi->base + SPIFLG);
+				buf_val = ioread32(davinci_spi->base + SPIBUF);
+
+				davinci_spi->get_rx(buf_val, davinci_spi);
+
+				count--;
+				if (count <= 0)
+					break;
+			}
+		} else {	/* Receive in Interrupt mode */
+			int i;
+
+			for (i = 0; i < davinci_spi->count; i++) {
+				set_io_bits(davinci_spi->base + SPIINT,
+						SPIINT_BITERR_INTR
+						| SPIINT_OVRRUN_INTR
+						| SPIINT_RX_INTR);
+
+				iowrite32(data1_reg_val,
+						davinci_spi->base + SPIDAT1);
+
+				while (ioread32(davinci_spi->base + SPIINT) &
+						SPIINT_RX_INTR)
+					cpu_relax();
+			}
+			iowrite32((data1_reg_val & 0x0ffcffff),
+					davinci_spi->base + SPIDAT1);
+		}
+	}
+
+	/*
+	 * Check for bit error, desync error,parity error,timeout error and
+	 * receive overflow errors
+	 */
+	int_status = ioread32(davinci_spi->base + SPIFLG);
+
+	ret = davinci_spi_check_error(davinci_spi, int_status);
+	if (ret != 0)
+		return ret;
+
+	/* SPI Framework maintains the count only in bytes so convert back */
+	davinci_spi->count *= conv;
+
+	return t->len;
+}
+
+/*
+ * davinci_spi_irq - probe function for SPI Master Controller
+ * @irq: IRQ number for this SPI Master
+ * @context_data: structure for SPI Master controller davinci_spi
+ *
+ * ISR will determine that interrupt arrives either for READ or WRITE command.
+ * According to command it will do the appropriate action. It will check
+ * transfer length and if it is not zero then dispatch transfer command again.
+ * If transfer length is zero then it will indicate the COMPLETION so that
+ * davinci_spi_bufs function can go ahead.
+ */
+static irqreturn_t davinci_spi_irq(s32 irq, void *context_data)
+{
+	struct davinci_spi *davinci_spi = context_data;
+	u32 int_status, rx_data = 0;
+	irqreturn_t ret = IRQ_NONE;
+
+	int_status = ioread32(davinci_spi->base + SPIFLG);
+	while ((int_status & SPIFLG_MASK) != 0) {
+		ret = IRQ_HANDLED;
+
+		if (likely(int_status & SPIFLG_RX_INTR_MASK)) {
+			rx_data = ioread32(davinci_spi->base + SPIBUF);
+			davinci_spi->get_rx(rx_data, davinci_spi);
+
+			/* Disable Receive Interrupt */
+			iowrite32(~SPIINT_RX_INTR,
+					davinci_spi->base + SPIINT);
+		} else
+			(void)davinci_spi_check_error(davinci_spi, int_status);
+
+		int_status = ioread32(davinci_spi->base + SPIFLG);
+	}
+
+	return ret;
+}
+
+/*
+ * davinci_spi_probe - probe function for SPI Master Controller
+ * @pdev: platform_device structure which contains plateform specific data
+ *
+ * According to Linux Device Model this function will be invoked by Linux
+ * with plateform_device struct which contains the device specific info.
+ * This function will map the SPI controller's memory, register IRQ,
+ * Reset SPI controller and setting its registers to default value.
+ * It will invoke spi_bitbang_start to create work queue so that client driver
+ * can register transfer method to work queue.
+ */
+static int davinci_spi_probe(struct platform_device *pdev)
+{
+	struct spi_master *master;
+	struct davinci_spi *davinci_spi;
+	struct davinci_spi_platform_data *pdata;
+	struct resource *r, *mem;
+	int ret = 0;
+
+	pdata = pdev->dev.platform_data;
+	if (pdata == NULL) {
+		ret = -ENODEV;
+		goto err;
+	}
+
+	master = spi_alloc_master(&pdev->dev, sizeof(struct davinci_spi));
+	if (master == NULL) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	dev_set_drvdata(&pdev->dev, master);
+
+	davinci_spi = spi_master_get_devdata(master);
+	if (davinci_spi == NULL) {
+		ret = -ENOENT;
+		goto free_master;
+	}
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (r == NULL) {
+		ret = -ENOENT;
+		goto free_master;
+	}
+
+	davinci_spi->pbase = r->start;
+	davinci_spi->region_size = resource_size(r);
+	davinci_spi->pdata = pdata;
+
+	mem = request_mem_region(r->start, davinci_spi->region_size,
+					pdev->name);
+	if (mem == NULL) {
+		ret = -EBUSY;
+		goto free_master;
+	}
+
+	davinci_spi->base = (struct davinci_spi_reg __iomem *)
+			ioremap(r->start, davinci_spi->region_size);
+	if (davinci_spi->base == NULL) {
+		ret = -ENOMEM;
+		goto release_region;
+	}
+
+	davinci_spi->irq = platform_get_irq(pdev, 0);
+	if (davinci_spi->irq <= 0) {
+		ret = -EINVAL;
+		goto unmap_io;
+	}
+
+	ret = request_irq(davinci_spi->irq, davinci_spi_irq, IRQF_DISABLED,
+			  dev_name(&pdev->dev), davinci_spi);
+	if (ret != 0) {
+		ret = -EAGAIN;
+		goto unmap_io;
+	}
+
+	davinci_spi->bitbang.master = spi_master_get(master);
+	if (davinci_spi->bitbang.master == NULL) {
+		ret = -ENODEV;
+		goto err1;
+	}
+
+	davinci_spi->clk = clk_get(&pdev->dev, NULL);
+	if (IS_ERR(davinci_spi->clk)) {
+		ret = -ENODEV;
+		goto put_master;
+	}
+	clk_enable(davinci_spi->clk);
+
+
+	master->bus_num = pdev->id;
+	master->num_chipselect = pdata->num_chipselect;
+	master->setup = davinci_spi_setup;
+
+	davinci_spi->bitbang.chipselect = davinci_spi_chipselect;
+	davinci_spi->bitbang.setup_transfer = davinci_spi_setup_transfer;
+	davinci_spi->bitbang.txrx_bufs = davinci_spi_bufs_pio;
+
+	davinci_spi->bitbang.flags = SPI_NO_CS | SPI_LSB_FIRST | SPI_LOOP;
+	if (davinci_spi->version == SPI_VERSION_2)
+		davinci_spi->bitbang.flags |= SPI_READY;
+
+	davinci_spi->version = pdata->version;
+	davinci_spi->get_rx = davinci_spi_rx_buf_u8;
+	davinci_spi->get_tx = davinci_spi_tx_buf_u8;
+
+	init_completion(&davinci_spi->done);
+
+	/* Reset In/OUT SPI modle */
+	iowrite32(0, davinci_spi->base + SPIGCR0);
+	udelay(100);
+	iowrite32(1, davinci_spi->base + SPIGCR0);
+
+	ret = spi_bitbang_start(&davinci_spi->bitbang);
+	if (ret != 0)
+		goto free_clk;
+
+	dev_info(&pdev->dev, "Controller at 0x%p (irq = %d) \n",
+		davinci_spi->base, davinci_spi->irq);
+
+	return ret;
+
+free_clk:
+	clk_disable(davinci_spi->clk);
+	clk_put(davinci_spi->clk);
+put_master:
+	spi_master_put(master);
+err1:
+	free_irq(davinci_spi->irq, davinci_spi);
+unmap_io:
+	iounmap(davinci_spi->base);
+release_region:
+	release_mem_region(davinci_spi->pbase, davinci_spi->region_size);
+free_master:
+	kfree(master);
+err:
+	return ret;
+}
+
+/*
+ * davinci_spi_remove - remove function for SPI Master Controller
+ * @pdev: platform_device structure which contains plateform specific data
+ *
+ * This function will do the reverse action of davinci_spi_probe function
+ * It will free the IRQ and SPI controller's memory region.
+ * It will also call spi_bitbang_stop to destroy the work queue which was
+ * created by spi_bitbang_start.
+ */
+static int __exit davinci_spi_remove(struct platform_device *pdev)
+{
+	struct davinci_spi *davinci_spi;
+	struct spi_master *master;
+
+	master = dev_get_drvdata(&pdev->dev);
+	davinci_spi = spi_master_get_devdata(master);
+
+	spi_bitbang_stop(&davinci_spi->bitbang);
+
+	clk_disable(davinci_spi->clk);
+	clk_put(davinci_spi->clk);
+	spi_master_put(master);
+	free_irq(davinci_spi->irq, davinci_spi);
+	iounmap(davinci_spi->base);
+	release_mem_region(davinci_spi->pbase, davinci_spi->region_size);
+
+	return 0;
+}
+
+static struct platform_driver davinci_spi_driver = {
+	.driver.name = "spi_davinci",
+	.remove = __exit_p(davinci_spi_remove),
+};
+
+static int __init davinci_spi_init(void)
+{
+	return platform_driver_probe(&davinci_spi_driver, davinci_spi_probe);
+}
+
+static void __exit davinci_spi_exit(void)
+{
+	platform_driver_unregister(&davinci_spi_driver);
+}
+
+module_init(davinci_spi_init);
+module_exit(davinci_spi_exit);
+
+MODULE_DESCRIPTION("TI DaVinci SPI Master Controller Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/spi/davinci_spi.h b/drivers/spi/davinci_spi.h
new file mode 100644
index 0000000..b6a314b
--- /dev/null
+++ b/drivers/spi/davinci_spi.h
@@ -0,0 +1,163 @@ 
+/*
+ * Copyright (C) 2009 Texas Instruments.
+ *
+ * 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
+ */
+
+#ifndef __DAVINCI_SPI_H
+#define __DAVINCI_SPI_H
+
+#define SPI_MAX_CHIPSELECT	2
+
+#define CS_DEFAULT	0xFF
+#define SCS0_SELECT	0x01
+#define SCS1_SELECT	0x02
+#define SCS2_SELECT	0x04
+#define SCS3_SELECT	0x08
+#define SCS4_SELECT	0x10
+#define SCS5_SELECT	0x20
+#define SCS6_SELECT	0x40
+#define SCS7_SELECT	0x80
+
+#define SPIFMT_PHASE_MASK	BIT(16)
+#define SPIFMT_POLARITY_MASK	BIT(17)
+#define SPIFMT_DISTIMER_MASK	BIT(18)
+#define SPIFMT_SHIFTDIR_MASK	BIT(20)
+#define SPIFMT_WAITENA_MASK	BIT(21)
+#define SPIFMT_PARITYENA_MASK	BIT(22)
+#define SPIFMT_ODD_PARITY_MASK	BIT(23)
+#define SPIFMT_WDELAY_MASK	0x3f000000u
+#define SPIFMT_WDELAY_SHIFT	24
+#define SPIFMT_CHARLEN_MASK	0x0000001Fu
+
+/* SPIGCR1 */
+#define SPIGCR1_SPIENA_MASK	0x01000000u
+
+/* SPIPC0 */
+#define SPIPC0_DIFUN_MASK	BIT(11)		/* MISO */
+#define SPIPC0_DOFUN_MASK	BIT(10)		/* MOSI */
+#define SPIPC0_CLKFUN_MASK	BIT(9)		/* CLK */
+#define SPIPC0_SPIENA_MASK	BIT(8)		/* nREADY */
+#define SPIPC0_EN1FUN_MASK	BIT(1)
+#define SPIPC0_EN0FUN_MASK	BIT(0)
+
+#define SPIINT_MASKALL		0x0101035F
+#define SPI_INTLVL_1		0x000001FFu
+#define SPI_INTLVL_0		0x00000000u
+
+/* SPIDAT1 */
+#define SPIDAT1_CSHOLD_MASK	BIT(28)
+#define SPIDAT1_CSHOLD_SHIFT	28
+#define SPIDAT1_CSNR_MASK	(BIT(17 | BIT(16))
+#define SPIDAT1_CSNR_SHIFT	16
+#define SPIDAT1_DFSEL_MASK	(BIT(24 | BIT(25))
+#define SPIGCR1_CLKMOD_MASK	BIT(1)
+#define SPIGCR1_MASTER_MASK     BIT(0)
+#define SPIGCR1_LOOPBACK_MASK	BIT(16)
+
+/* SPIBUF */
+#define SPIBUF_TXFULL_MASK	BIT(29)
+#define SPIBUF_RXEMPTY_MASK	BIT(31)
+
+/* Error Masks */
+#define SPIFLG_DLEN_ERR_MASK		BIT(0)
+#define SPIFLG_TIMEOUT_MASK		BIT(1)
+#define SPIFLG_PARERR_MASK		BIT(2)
+#define SPIFLG_DESYNC_MASK		BIT(3)
+#define SPIFLG_BITERR_MASK		BIT(4)
+#define SPIFLG_OVRRUN_MASK		BIT(6)
+#define SPIFLG_RX_INTR_MASK		BIT(8)
+#define SPIFLG_TX_INTR_MASK		BIT(9)
+#define SPIFLG_BUF_INIT_ACTIVE_MASK	BIT(24)
+#define SPIFLG_MASK			(SPIFLG_DLEN_ERR_MASK \
+				| SPIFLG_TIMEOUT_MASK | SPIFLG_PARERR_MASK \
+				| SPIFLG_DESYNC_MASK | SPIFLG_BITERR_MASK \
+				| SPIFLG_OVRRUN_MASK | SPIFLG_RX_INTR_MASK \
+				| SPIFLG_TX_INTR_MASK \
+				| SPIFLG_BUF_INIT_ACTIVE_MASK)
+
+#define SPIINT_DLEN_ERR_INTR	BIT(0)
+#define SPIINT_TIMEOUT_INTR	BIT(1)
+#define SPIINT_PARERR_INTR	BIT(2)
+#define SPIINT_DESYNC_INTR	BIT(3)
+#define SPIINT_BITERR_INTR	BIT(4)
+#define SPIINT_OVRRUN_INTR	BIT(6)
+#define SPIINT_RX_INTR		BIT(8)
+#define SPIINT_TX_INTR		BIT(9)
+#define SPIINT_DMA_REQ_EN	BIT(16)
+#define SPIINT_ENABLE_HIGHZ	BIT(24)
+
+#define SPI_T2CDELAY_SHIFT	16
+#define SPI_C2TDELAY_SHIFT	24
+
+/* SPI Controller registers */
+#define SPIGCR0		0x00
+#define SPIGCR1		0x04
+#define SPIINT		0x08
+#define SPILVL		0x0c
+#define SPIFLG		0x10
+#define SPIPC0		0x14
+#define SPIPC1		0x18
+#define SPIPC2		0x1c
+#define SPIPC3		0x20
+#define SPIPC4		0x24
+#define SPIPC5		0x28
+#define SPIPC6		0x2c
+#define SPIPC7		0x30
+#define SPIPC8		0x34
+#define SPIDAT0		0x38
+#define SPIDAT1		0x3c
+#define SPIBUF		0x40
+#define SPIEMU		0x44
+#define SPIDELAY	0x48
+#define SPIDEF		0x4c
+#define SPIFMT0		0x50
+#define SPIFMT1		0x54
+#define SPIFMT2		0x58
+#define SPIFMT3		0x5c
+#define TGINTVEC0	0x60
+#define TGINTVEC1	0x64
+
+struct davinci_spi_slave {
+	u32	cmd_to_write;
+	u32	clk_ctrl_to_write;
+	u32	bytes_per_word;
+	u8	active_cs;
+};
+
+/* SPI Controller driver's private data. */
+struct davinci_spi {
+	struct spi_bitbang	bitbang;
+	struct clk		*clk;
+
+	u8			version;
+	resource_size_t		pbase;
+	void __iomem		*base;
+	size_t			region_size;
+	u32			irq;
+	struct completion	done;
+
+	const void		*tx;
+	void			*rx;
+	int			count;
+	struct			davinci_spi_platform_data *pdata;
+
+	void			(*get_rx)(u32 rx_data, struct davinci_spi *);
+	u32			(*get_tx)(struct davinci_spi *);
+
+	struct davinci_spi_slave slave[SPI_MAX_CHIPSELECT];
+};
+
+#endif /* __DAVINCI_SPI_H */