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authorSandeep Paulraj <s-paulraj@ti.com>2009-12-17 01:02:18 +0300
committerGrant Likely <grant.likely@secretlab.ca>2010-01-20 23:49:34 +0300
commit358934a60d2180dcd1ed20691dbb66d4fb977ab2 (patch)
treefcebf0327a981f9062d519db40181fb961c3adcf /drivers/spi
parent7284ce6c9f6153d1777df5f310c959724d1bd446 (diff)
downloadlinux-358934a60d2180dcd1ed20691dbb66d4fb977ab2.tar.xz
spi: Add SPI master driver for DaVinci/DA8xx
This patch adds support for a SPI master driver for the DaVinci series of SOCs Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com> Signed-off-by: Mark A. Greer <mgreer@mvista.com> Signed-off-by: Philby John <pjohn@in.mvista.com> Signed-off-by: Sudhakar Rajashekhara <sudhakar.raj@ti.com> Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/Kconfig7
-rw-r--r--drivers/spi/Makefile1
-rw-r--r--drivers/spi/davinci_spi.c1255
3 files changed, 1263 insertions, 0 deletions
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index f55eb0107336..82dabbca00c1 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -100,6 +100,13 @@ config SPI_BUTTERFLY
inexpensive battery powered microcontroller evaluation board.
This same cable can be used to flash new firmware.
+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_GPIO
tristate "GPIO-based bitbanging SPI Master"
depends on GENERIC_GPIO
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index f3d2810ba11c..84b490fb7f8a 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_SPI_BFIN) += spi_bfin5xx.o
obj-$(CONFIG_SPI_BITBANG) += spi_bitbang.o
obj-$(CONFIG_SPI_AU1550) += au1550_spi.o
obj-$(CONFIG_SPI_BUTTERFLY) += spi_butterfly.o
+obj-$(CONFIG_SPI_DAVINCI) += davinci_spi.o
obj-$(CONFIG_SPI_DESIGNWARE) += dw_spi.o
obj-$(CONFIG_SPI_DW_PCI) += dw_spi_pci.o
obj-$(CONFIG_SPI_GPIO) += spi_gpio.o
diff --git a/drivers/spi/davinci_spi.c b/drivers/spi/davinci_spi.c
new file mode 100644
index 000000000000..225ab60b02c4
--- /dev/null
+++ b/drivers/spi/davinci_spi.c
@@ -0,0 +1,1255 @@
+/*
+ * 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/dma-mapping.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+
+#include <mach/spi.h>
+#include <mach/edma.h>
+
+#define SPI_NO_RESOURCE ((resource_size_t)-1)
+
+#define SPI_MAX_CHIPSELECT 2
+
+#define CS_DEFAULT 0xFF
+
+#define SPI_BUFSIZ (SMP_CACHE_BYTES + 1)
+#define DAVINCI_DMA_DATA_TYPE_S8 0x01
+#define DAVINCI_DMA_DATA_TYPE_S16 0x02
+#define DAVINCI_DMA_DATA_TYPE_S32 0x04
+
+#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_SHIFT 28
+#define SPIDAT1_CSNR_SHIFT 16
+#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;
+};
+
+/* We have 2 DMA channels per CS, one for RX and one for TX */
+struct davinci_spi_dma {
+ int dma_tx_channel;
+ int dma_rx_channel;
+ int dma_tx_sync_dev;
+ int dma_rx_sync_dev;
+ enum dma_event_q eventq;
+
+ struct completion dma_tx_completion;
+ struct completion dma_rx_completion;
+};
+
+/* 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;
+ u8 *tmp_buf;
+ int count;
+ struct davinci_spi_dma *dma_channels;
+ 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];
+};
+
+static unsigned use_dma;
+
+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);
+}
+
+static void davinci_spi_set_dma_req(const struct spi_device *spi, int enable)
+{
+ struct davinci_spi *davinci_spi = spi_master_get_devdata(spi->master);
+
+ if (enable)
+ set_io_bits(davinci_spi->base + SPIINT, SPIINT_DMA_REQ_EN);
+ else
+ clear_io_bits(davinci_spi->base + SPIINT, SPIINT_DMA_REQ_EN);
+}
+
+/*
+ * 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;
+}
+
+static void davinci_spi_dma_rx_callback(unsigned lch, u16 ch_status, void *data)
+{
+ struct spi_device *spi = (struct spi_device *)data;
+ struct davinci_spi *davinci_spi;
+ struct davinci_spi_dma *davinci_spi_dma;
+ struct davinci_spi_platform_data *pdata;
+
+ davinci_spi = spi_master_get_devdata(spi->master);
+ davinci_spi_dma = &(davinci_spi->dma_channels[spi->chip_select]);
+ pdata = davinci_spi->pdata;
+
+ if (ch_status == DMA_COMPLETE)
+ edma_stop(davinci_spi_dma->dma_rx_channel);
+ else
+ edma_clean_channel(davinci_spi_dma->dma_rx_channel);
+
+ complete(&davinci_spi_dma->dma_rx_completion);
+ /* We must disable the DMA RX request */
+ davinci_spi_set_dma_req(spi, 0);
+}
+
+static void davinci_spi_dma_tx_callback(unsigned lch, u16 ch_status, void *data)
+{
+ struct spi_device *spi = (struct spi_device *)data;
+ struct davinci_spi *davinci_spi;
+ struct davinci_spi_dma *davinci_spi_dma;
+ struct davinci_spi_platform_data *pdata;
+
+ davinci_spi = spi_master_get_devdata(spi->master);
+ davinci_spi_dma = &(davinci_spi->dma_channels[spi->chip_select]);
+ pdata = davinci_spi->pdata;
+
+ if (ch_status == DMA_COMPLETE)
+ edma_stop(davinci_spi_dma->dma_tx_channel);
+ else
+ edma_clean_channel(davinci_spi_dma->dma_tx_channel);
+
+ complete(&davinci_spi_dma->dma_tx_completion);
+ /* We must disable the DMA TX request */
+ davinci_spi_set_dma_req(spi, 0);
+}
+
+static int davinci_spi_request_dma(struct spi_device *spi)
+{
+ struct davinci_spi *davinci_spi;
+ struct davinci_spi_dma *davinci_spi_dma;
+ struct davinci_spi_platform_data *pdata;
+ struct device *sdev;
+ int r;
+
+ davinci_spi = spi_master_get_devdata(spi->master);
+ davinci_spi_dma = &davinci_spi->dma_channels[spi->chip_select];
+ pdata = davinci_spi->pdata;
+ sdev = davinci_spi->bitbang.master->dev.parent;
+
+ r = edma_alloc_channel(davinci_spi_dma->dma_rx_sync_dev,
+ davinci_spi_dma_rx_callback, spi,
+ davinci_spi_dma->eventq);
+ if (r < 0) {
+ dev_dbg(sdev, "Unable to request DMA channel for SPI RX\n");
+ return -EAGAIN;
+ }
+ davinci_spi_dma->dma_rx_channel = r;
+ r = edma_alloc_channel(davinci_spi_dma->dma_tx_sync_dev,
+ davinci_spi_dma_tx_callback, spi,
+ davinci_spi_dma->eventq);
+ if (r < 0) {
+ edma_free_channel(davinci_spi_dma->dma_rx_channel);
+ davinci_spi_dma->dma_rx_channel = -1;
+ dev_dbg(sdev, "Unable to request DMA channel for SPI TX\n");
+ return -EAGAIN;
+ }
+ davinci_spi_dma->dma_tx_channel = r;
+
+ 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;
+ struct davinci_spi *davinci_spi;
+ struct davinci_spi_dma *davinci_spi_dma;
+ struct device *sdev;
+
+ davinci_spi = spi_master_get_devdata(spi->master);
+ sdev = davinci_spi->bitbang.master->dev.parent;
+
+ /* if bits per word length is zero then set it default 8 */
+ if (!spi->bits_per_word)
+ spi->bits_per_word = 8;
+
+ davinci_spi->slave[spi->chip_select].cmd_to_write = 0;
+
+ if (use_dma && davinci_spi->dma_channels) {
+ davinci_spi_dma = &davinci_spi->dma_channels[spi->chip_select];
+
+ if ((davinci_spi_dma->dma_rx_channel == -1)
+ || (davinci_spi_dma->dma_tx_channel == -1)) {
+ retval = davinci_spi_request_dma(spi);
+ if (retval < 0)
+ return retval;
+ }
+ }
+
+ /*
+ * SPI in DaVinci and DA8xx operate between
+ * 600 KHz and 50 MHz
+ */
+ if (spi->max_speed_hz < 600000 || spi->max_speed_hz > 50000000) {
+ dev_dbg(sdev, "Operating frequency is not in acceptable "
+ "range\n");
+ return -EINVAL;
+ }
+
+ /*
+ * Set up SPIFMTn register, unique to this chipselect.
+ *
+ * NOTE: we could do all of these with one write. Also, some
+ * of the "version 2" features are found in chips that don't
+ * support all of them...
+ */
+ 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);
+
+ /*
+ * 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)
+ */
+
+ 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);
+ }
+
+ retval = davinci_spi_setup_transfer(spi, NULL);
+
+ return retval;
+}
+
+static void davinci_spi_cleanup(struct spi_device *spi)
+{
+ struct davinci_spi *davinci_spi = spi_master_get_devdata(spi->master);
+ struct davinci_spi_dma *davinci_spi_dma;
+
+ davinci_spi_dma = &davinci_spi->dma_channels[spi->chip_select];
+
+ if (use_dma && davinci_spi->dma_channels) {
+ davinci_spi_dma = &davinci_spi->dma_channels[spi->chip_select];
+
+ if ((davinci_spi_dma->dma_rx_channel != -1)
+ && (davinci_spi_dma->dma_tx_channel != -1)) {
+ edma_free_channel(davinci_spi_dma->dma_tx_channel);
+ edma_free_channel(davinci_spi_dma->dma_rx_channel);
+ }
+ }
+}
+
+static int davinci_spi_bufs_prep(struct spi_device *spi,
+ struct davinci_spi *davinci_spi)
+{
+ int op_mode = 0;
+
+ /*
+ * REVISIT unless devices disagree about SPI_LOOP or
+ * SPI_READY (SPI_NO_CS only allows one device!), this
+ * should not need to be done before each message...
+ * optimize for both flags staying cleared.
+ */
+
+ 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);
+
+ return 0;
+}
+
+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 until 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 based 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);
+
+ ret = davinci_spi_bufs_prep(spi, davinci_spi);
+ if (ret)
+ return ret;
+
+ /* 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;
+}
+
+#define DAVINCI_DMA_DATA_TYPE_S8 0x01
+#define DAVINCI_DMA_DATA_TYPE_S16 0x02
+#define DAVINCI_DMA_DATA_TYPE_S32 0x04
+
+static int davinci_spi_bufs_dma(struct spi_device *spi, struct spi_transfer *t)
+{
+ struct davinci_spi *davinci_spi;
+ int int_status = 0;
+ int count, temp_count;
+ u8 conv = 1;
+ u8 tmp;
+ u32 data1_reg_val;
+ struct davinci_spi_dma *davinci_spi_dma;
+ int word_len, data_type, ret;
+ unsigned long tx_reg, rx_reg;
+ struct davinci_spi_platform_data *pdata;
+ struct device *sdev;
+
+ davinci_spi = spi_master_get_devdata(spi->master);
+ pdata = davinci_spi->pdata;
+ sdev = davinci_spi->bitbang.master->dev.parent;
+
+ davinci_spi_dma = &davinci_spi->dma_channels[spi->chip_select];
+
+ tx_reg = (unsigned long)davinci_spi->pbase + SPIDAT1;
+ rx_reg = (unsigned long)davinci_spi->pbase + SPIBUF;
+
+ davinci_spi->tx = t->tx_buf;
+ davinci_spi->rx = t->rx_buf;
+
+ /* convert len to words based 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);
+
+ init_completion(&davinci_spi_dma->dma_rx_completion);
+ init_completion(&davinci_spi_dma->dma_tx_completion);
+
+ word_len = conv * 8;
+
+ if (word_len <= 8)
+ data_type = DAVINCI_DMA_DATA_TYPE_S8;
+ else if (word_len <= 16)
+ data_type = DAVINCI_DMA_DATA_TYPE_S16;
+ else if (word_len <= 32)
+ data_type = DAVINCI_DMA_DATA_TYPE_S32;
+ else
+ return -EINVAL;
+
+ ret = davinci_spi_bufs_prep(spi, davinci_spi);
+ if (ret)
+ return ret;
+
+ /* Put delay val if required */
+ iowrite32(0 | (pdata->c2tdelay << SPI_C2TDELAY_SHIFT) |
+ (pdata->t2cdelay << SPI_T2CDELAY_SHIFT),
+ davinci_spi->base + SPIDELAY);
+
+ count = davinci_spi->count; /* the number of elements */
+ data1_reg_val = pdata->cs_hold << SPIDAT1_CSHOLD_SHIFT;
+
+ /* CS default = 0xFF */
+ tmp = ~(0x1 << spi->chip_select);
+
+ clear_io_bits(davinci_spi->base + SPIDEF, ~tmp);
+
+ data1_reg_val |= tmp << SPIDAT1_CSNR_SHIFT;
+
+ /* disable all interrupts for dma transfers */
+ clear_io_bits(davinci_spi->base + SPIINT, SPIINT_MASKALL);
+ /* Disable SPI to write configuration bits in SPIDAT */
+ clear_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_SPIENA_MASK);
+ iowrite32(data1_reg_val, davinci_spi->base + SPIDAT1);
+ /* Enable SPI */
+ set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_SPIENA_MASK);
+
+ while ((ioread32(davinci_spi->base + SPIBUF)
+ & SPIBUF_RXEMPTY_MASK) == 0)
+ cpu_relax();
+
+
+ if (t->tx_buf) {
+ t->tx_dma = dma_map_single(&spi->dev, (void *)t->tx_buf, count,
+ DMA_TO_DEVICE);
+ if (dma_mapping_error(&spi->dev, t->tx_dma)) {
+ dev_dbg(sdev, "Unable to DMA map a %d bytes"
+ " TX buffer\n", count);
+ return -ENOMEM;
+ }
+ temp_count = count;
+ } else {
+ /* We need TX clocking for RX transaction */
+ t->tx_dma = dma_map_single(&spi->dev,
+ (void *)davinci_spi->tmp_buf, count + 1,
+ DMA_TO_DEVICE);
+ if (dma_mapping_error(&spi->dev, t->tx_dma)) {
+ dev_dbg(sdev, "Unable to DMA map a %d bytes"
+ " TX tmp buffer\n", count);
+ return -ENOMEM;
+ }
+ temp_count = count + 1;
+ }
+
+ edma_set_transfer_params(davinci_spi_dma->dma_tx_channel,
+ data_type, temp_count, 1, 0, ASYNC);
+ edma_set_dest(davinci_spi_dma->dma_tx_channel, tx_reg, INCR, W8BIT);
+ edma_set_src(davinci_spi_dma->dma_tx_channel, t->tx_dma, INCR, W8BIT);
+ edma_set_src_index(davinci_spi_dma->dma_tx_channel, data_type, 0);
+ edma_set_dest_index(davinci_spi_dma->dma_tx_channel, 0, 0);
+
+ if (t->rx_buf) {
+ /* initiate transaction */
+ iowrite32(data1_reg_val, davinci_spi->base + SPIDAT1);
+
+ t->rx_dma = dma_map_single(&spi->dev, (void *)t->rx_buf, count,
+ DMA_FROM_DEVICE);
+ if (dma_mapping_error(&spi->dev, t->rx_dma)) {
+ dev_dbg(sdev, "Couldn't DMA map a %d bytes RX buffer\n",
+ count);
+ if (t->tx_buf != NULL)
+ dma_unmap_single(NULL, t->tx_dma,
+ count, DMA_TO_DEVICE);
+ return -ENOMEM;
+ }
+ edma_set_transfer_params(davinci_spi_dma->dma_rx_channel,
+ data_type, count, 1, 0, ASYNC);
+ edma_set_src(davinci_spi_dma->dma_rx_channel,
+ rx_reg, INCR, W8BIT);
+ edma_set_dest(davinci_spi_dma->dma_rx_channel,
+ t->rx_dma, INCR, W8BIT);
+ edma_set_src_index(davinci_spi_dma->dma_rx_channel, 0, 0);
+ edma_set_dest_index(davinci_spi_dma->dma_rx_channel,
+ data_type, 0);
+ }
+
+ if ((t->tx_buf) || (t->rx_buf))
+ edma_start(davinci_spi_dma->dma_tx_channel);
+
+ if (t->rx_buf)
+ edma_start(davinci_spi_dma->dma_rx_channel);
+
+ if ((t->rx_buf) || (t->tx_buf))
+ davinci_spi_set_dma_req(spi, 1);
+
+ if (t->tx_buf)
+ wait_for_completion_interruptible(
+ &davinci_spi_dma->dma_tx_completion);
+
+ if (t->rx_buf)
+ wait_for_completion_interruptible(
+ &davinci_spi_dma->dma_rx_completion);
+
+ dma_unmap_single(NULL, t->tx_dma, temp_count, DMA_TO_DEVICE);
+
+ if (t->rx_buf)
+ dma_unmap_single(NULL, t->rx_dma, count, DMA_FROM_DEVICE);
+
+ /*
+ * 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 - IRQ handler for DaVinci SPI
+ * @irq: IRQ number for this SPI Master
+ * @context_data: structure for SPI Master controller davinci_spi
+ */
+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_RX_INTR_MASK)) {
+ if (likely(int_status & SPIFLG_RX_INTR_MASK)) {
+ ret = IRQ_HANDLED;
+
+ rx_data = ioread32(davinci_spi->base + SPIBUF);
+ davinci_spi->get_rx(rx_data, davinci_spi);
+
+ /* Disable Receive Interrupt */
+ iowrite32(~(SPIINT_RX_INTR | SPIINT_TX_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
+ */
+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;
+ resource_size_t dma_rx_chan = SPI_NO_RESOURCE;
+ resource_size_t dma_tx_chan = SPI_NO_RESOURCE;
+ resource_size_t dma_eventq = SPI_NO_RESOURCE;
+ int i = 0, 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)
+ goto unmap_io;
+
+ /* Allocate tmp_buf for tx_buf */
+ davinci_spi->tmp_buf = kzalloc(SPI_BUFSIZ, GFP_KERNEL);
+ if (davinci_spi->tmp_buf == NULL) {
+ ret = -ENOMEM;
+ goto irq_free;
+ }
+
+ davinci_spi->bitbang.master = spi_master_get(master);
+ if (davinci_spi->bitbang.master == NULL) {
+ ret = -ENODEV;
+ goto free_tmp_buf;
+ }
+
+ 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;
+ master->cleanup = davinci_spi_cleanup;
+
+ davinci_spi->bitbang.chipselect = davinci_spi_chipselect;
+ davinci_spi->bitbang.setup_transfer = davinci_spi_setup_transfer;
+
+ davinci_spi->version = pdata->version;
+ use_dma = pdata->use_dma;
+
+ 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;
+
+ if (use_dma) {
+ r = platform_get_resource(pdev, IORESOURCE_DMA, 0);
+ if (r)
+ dma_rx_chan = r->start;
+ r = platform_get_resource(pdev, IORESOURCE_DMA, 1);
+ if (r)
+ dma_tx_chan = r->start;
+ r = platform_get_resource(pdev, IORESOURCE_DMA, 2);
+ if (r)
+ dma_eventq = r->start;
+ }
+
+ if (!use_dma ||
+ dma_rx_chan == SPI_NO_RESOURCE ||
+ dma_tx_chan == SPI_NO_RESOURCE ||
+ dma_eventq == SPI_NO_RESOURCE) {
+ davinci_spi->bitbang.txrx_bufs = davinci_spi_bufs_pio;
+ use_dma = 0;
+ } else {
+ davinci_spi->bitbang.txrx_bufs = davinci_spi_bufs_dma;
+ davinci_spi->dma_channels = kzalloc(master->num_chipselect
+ * sizeof(struct davinci_spi_dma), GFP_KERNEL);
+ if (davinci_spi->dma_channels == NULL) {
+ ret = -ENOMEM;
+ goto free_clk;
+ }
+
+ for (i = 0; i < master->num_chipselect; i++) {
+ davinci_spi->dma_channels[i].dma_rx_channel = -1;
+ davinci_spi->dma_channels[i].dma_rx_sync_dev =
+ dma_rx_chan;
+ davinci_spi->dma_channels[i].dma_tx_channel = -1;
+ davinci_spi->dma_channels[i].dma_tx_sync_dev =
+ dma_tx_chan;
+ davinci_spi->dma_channels[i].eventq = dma_eventq;
+ }
+ dev_info(&pdev->dev, "DaVinci SPI driver in EDMA mode\n"
+ "Using RX channel = %d , TX channel = %d and "
+ "event queue = %d", dma_rx_chan, dma_tx_chan,
+ dma_eventq);
+ }
+
+ 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 module */
+ iowrite32(0, davinci_spi->base + SPIGCR0);
+ udelay(100);
+ iowrite32(1, davinci_spi->base + SPIGCR0);
+
+ /* 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);
+
+ ret = spi_bitbang_start(&davinci_spi->bitbang);
+ if (ret)
+ goto free_clk;
+
+ dev_info(&pdev->dev, "Controller at 0x%p \n", davinci_spi->base);
+
+ if (!pdata->poll_mode)
+ dev_info(&pdev->dev, "Operating in interrupt mode"
+ " using IRQ %d\n", davinci_spi->irq);
+
+ return ret;
+
+free_clk:
+ clk_disable(davinci_spi->clk);
+ clk_put(davinci_spi->clk);
+put_master:
+ spi_master_put(master);
+free_tmp_buf:
+ kfree(davinci_spi->tmp_buf);
+irq_free:
+ 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);
+ kfree(davinci_spi->tmp_buf);
+ 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);
+}
+module_init(davinci_spi_init);
+
+static void __exit davinci_spi_exit(void)
+{
+ platform_driver_unregister(&davinci_spi_driver);
+}
+module_exit(davinci_spi_exit);
+
+MODULE_DESCRIPTION("TI DaVinci SPI Master Controller Driver");
+MODULE_LICENSE("GPL");