spi: reorganize drivers

Sort the SPI makefile and enforce the naming convention spi_*.c for
spi drivers.

This change also rolls the contents of atmel_spi.h into the .c file
since there is only one user of that particular include file.

v2: - Use 'spi-' prefix instead of 'spi_' to match what seems to be
      be the predominant pattern for subsystem prefixes.
    - Clean up filenames in Kconfig and header comment blocks

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 1816 insertions, 0 deletions

diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
new file mode 100644
index 00000000000..dc25bee8d33
--- /dev/null
+++ b/drivers/spi/spi-pxa2xx.c
@@ -0,0 +1,1816 @@
+/*
+ * Copyright (C) 2005 Stephen Street / StreetFire Sound Labs
+ *
+ * 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.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/ioport.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/spi/pxa2xx_spi.h>
+#include <linux/dma-mapping.h>
+#include <linux/spi/spi.h>
+#include <linux/workqueue.h>
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/slab.h>
+
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/delay.h>
+
+
+MODULE_AUTHOR("Stephen Street");
+MODULE_DESCRIPTION("PXA2xx SSP SPI Controller");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:pxa2xx-spi");
+
+#define MAX_BUSES 3
+
+#define TIMOUT_DFLT		1000
+
+#define DMA_INT_MASK		(DCSR_ENDINTR | DCSR_STARTINTR | DCSR_BUSERR)
+#define RESET_DMA_CHANNEL	(DCSR_NODESC | DMA_INT_MASK)
+#define IS_DMA_ALIGNED(x)	((((u32)(x)) & 0x07) == 0)
+#define MAX_DMA_LEN		8191
+#define DMA_ALIGNMENT		8
+
+/*
+ * for testing SSCR1 changes that require SSP restart, basically
+ * everything except the service and interrupt enables, the pxa270 developer
+ * manual says only SSCR1_SCFR, SSCR1_SPH, SSCR1_SPO need to be in this
+ * list, but the PXA255 dev man says all bits without really meaning the
+ * service and interrupt enables
+ */
+#define SSCR1_CHANGE_MASK (SSCR1_TTELP | SSCR1_TTE | SSCR1_SCFR \
+				| SSCR1_ECRA | SSCR1_ECRB | SSCR1_SCLKDIR \
+				| SSCR1_SFRMDIR | SSCR1_RWOT | SSCR1_TRAIL \
+				| SSCR1_IFS | SSCR1_STRF | SSCR1_EFWR \
+				| SSCR1_RFT | SSCR1_TFT | SSCR1_MWDS \
+				| SSCR1_SPH | SSCR1_SPO | SSCR1_LBM)
+
+#define DEFINE_SSP_REG(reg, off) \
+static inline u32 read_##reg(void const __iomem *p) \
+{ return __raw_readl(p + (off)); } \
+\
+static inline void write_##reg(u32 v, void __iomem *p) \
+{ __raw_writel(v, p + (off)); }
+
+DEFINE_SSP_REG(SSCR0, 0x00)
+DEFINE_SSP_REG(SSCR1, 0x04)
+DEFINE_SSP_REG(SSSR, 0x08)
+DEFINE_SSP_REG(SSITR, 0x0c)
+DEFINE_SSP_REG(SSDR, 0x10)
+DEFINE_SSP_REG(SSTO, 0x28)
+DEFINE_SSP_REG(SSPSP, 0x2c)
+
+#define START_STATE ((void*)0)
+#define RUNNING_STATE ((void*)1)
+#define DONE_STATE ((void*)2)
+#define ERROR_STATE ((void*)-1)
+
+#define QUEUE_RUNNING 0
+#define QUEUE_STOPPED 1
+
+struct driver_data {
+	/* Driver model hookup */
+	struct platform_device *pdev;
+
+	/* SSP Info */
+	struct ssp_device *ssp;
+
+	/* SPI framework hookup */
+	enum pxa_ssp_type ssp_type;
+	struct spi_master *master;
+
+	/* PXA hookup */
+	struct pxa2xx_spi_master *master_info;
+
+	/* DMA setup stuff */
+	int rx_channel;
+	int tx_channel;
+	u32 *null_dma_buf;
+
+	/* SSP register addresses */
+	void __iomem *ioaddr;
+	u32 ssdr_physical;
+
+	/* SSP masks*/
+	u32 dma_cr1;
+	u32 int_cr1;
+	u32 clear_sr;
+	u32 mask_sr;
+
+	/* Driver message queue */
+	struct workqueue_struct	*workqueue;
+	struct work_struct pump_messages;
+	spinlock_t lock;
+	struct list_head queue;
+	int busy;
+	int run;
+
+	/* Message Transfer pump */
+	struct tasklet_struct pump_transfers;
+
+	/* Current message transfer state info */
+	struct spi_message* cur_msg;
+	struct spi_transfer* cur_transfer;
+	struct chip_data *cur_chip;
+	size_t len;
+	void *tx;
+	void *tx_end;
+	void *rx;
+	void *rx_end;
+	int dma_mapped;
+	dma_addr_t rx_dma;
+	dma_addr_t tx_dma;
+	size_t rx_map_len;
+	size_t tx_map_len;
+	u8 n_bytes;
+	u32 dma_width;
+	int (*write)(struct driver_data *drv_data);
+	int (*read)(struct driver_data *drv_data);
+	irqreturn_t (*transfer_handler)(struct driver_data *drv_data);
+	void (*cs_control)(u32 command);
+};
+
+struct chip_data {
+	u32 cr0;
+	u32 cr1;
+	u32 psp;
+	u32 timeout;
+	u8 n_bytes;
+	u32 dma_width;
+	u32 dma_burst_size;
+	u32 threshold;
+	u32 dma_threshold;
+	u8 enable_dma;
+	u8 bits_per_word;
+	u32 speed_hz;
+	union {
+		int gpio_cs;
+		unsigned int frm;
+	};
+	int gpio_cs_inverted;
+	int (*write)(struct driver_data *drv_data);
+	int (*read)(struct driver_data *drv_data);
+	void (*cs_control)(u32 command);
+};
+
+static void pump_messages(struct work_struct *work);
+
+static void cs_assert(struct driver_data *drv_data)
+{
+	struct chip_data *chip = drv_data->cur_chip;
+
+	if (drv_data->ssp_type == CE4100_SSP) {
+		write_SSSR(drv_data->cur_chip->frm, drv_data->ioaddr);
+		return;
+	}
+
+	if (chip->cs_control) {
+		chip->cs_control(PXA2XX_CS_ASSERT);
+		return;
+	}
+
+	if (gpio_is_valid(chip->gpio_cs))
+		gpio_set_value(chip->gpio_cs, chip->gpio_cs_inverted);
+}
+
+static void cs_deassert(struct driver_data *drv_data)
+{
+	struct chip_data *chip = drv_data->cur_chip;
+
+	if (drv_data->ssp_type == CE4100_SSP)
+		return;
+
+	if (chip->cs_control) {
+		chip->cs_control(PXA2XX_CS_DEASSERT);
+		return;
+	}
+
+	if (gpio_is_valid(chip->gpio_cs))
+		gpio_set_value(chip->gpio_cs, !chip->gpio_cs_inverted);
+}
+
+static void write_SSSR_CS(struct driver_data *drv_data, u32 val)
+{
+	void __iomem *reg = drv_data->ioaddr;
+
+	if (drv_data->ssp_type == CE4100_SSP)
+		val |= read_SSSR(reg) & SSSR_ALT_FRM_MASK;
+
+	write_SSSR(val, reg);
+}
+
+static int pxa25x_ssp_comp(struct driver_data *drv_data)
+{
+	if (drv_data->ssp_type == PXA25x_SSP)
+		return 1;
+	if (drv_data->ssp_type == CE4100_SSP)
+		return 1;
+	return 0;
+}
+
+static int flush(struct driver_data *drv_data)
+{
+	unsigned long limit = loops_per_jiffy << 1;
+
+	void __iomem *reg = drv_data->ioaddr;
+
+	do {
+		while (read_SSSR(reg) & SSSR_RNE) {
+			read_SSDR(reg);
+		}
+	} while ((read_SSSR(reg) & SSSR_BSY) && --limit);
+	write_SSSR_CS(drv_data, SSSR_ROR);
+
+	return limit;
+}
+
+static int null_writer(struct driver_data *drv_data)
+{
+	void __iomem *reg = drv_data->ioaddr;
+	u8 n_bytes = drv_data->n_bytes;
+
+	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
+		|| (drv_data->tx == drv_data->tx_end))
+		return 0;
+
+	write_SSDR(0, reg);
+	drv_data->tx += n_bytes;
+
+	return 1;
+}
+
+static int null_reader(struct driver_data *drv_data)
+{
+	void __iomem *reg = drv_data->ioaddr;
+	u8 n_bytes = drv_data->n_bytes;
+
+	while ((read_SSSR(reg) & SSSR_RNE)
+		&& (drv_data->rx < drv_data->rx_end)) {
+		read_SSDR(reg);
+		drv_data->rx += n_bytes;
+	}
+
+	return drv_data->rx == drv_data->rx_end;
+}
+
+static int u8_writer(struct driver_data *drv_data)
+{
+	void __iomem *reg = drv_data->ioaddr;
+
+	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
+		|| (drv_data->tx == drv_data->tx_end))
+		return 0;
+
+	write_SSDR(*(u8 *)(drv_data->tx), reg);
+	++drv_data->tx;
+
+	return 1;
+}
+
+static int u8_reader(struct driver_data *drv_data)
+{
+	void __iomem *reg = drv_data->ioaddr;
+
+	while ((read_SSSR(reg) & SSSR_RNE)
+		&& (drv_data->rx < drv_data->rx_end)) {
+		*(u8 *)(drv_data->rx) = read_SSDR(reg);
+		++drv_data->rx;
+	}
+
+	return drv_data->rx == drv_data->rx_end;
+}
+
+static int u16_writer(struct driver_data *drv_data)
+{
+	void __iomem *reg = drv_data->ioaddr;
+
+	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
+		|| (drv_data->tx == drv_data->tx_end))
+		return 0;
+
+	write_SSDR(*(u16 *)(drv_data->tx), reg);
+	drv_data->tx += 2;
+
+	return 1;
+}
+
+static int u16_reader(struct driver_data *drv_data)
+{
+	void __iomem *reg = drv_data->ioaddr;
+
+	while ((read_SSSR(reg) & SSSR_RNE)
+		&& (drv_data->rx < drv_data->rx_end)) {
+		*(u16 *)(drv_data->rx) = read_SSDR(reg);
+		drv_data->rx += 2;
+	}
+
+	return drv_data->rx == drv_data->rx_end;
+}
+
+static int u32_writer(struct driver_data *drv_data)
+{
+	void __iomem *reg = drv_data->ioaddr;
+
+	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
+		|| (drv_data->tx == drv_data->tx_end))
+		return 0;
+
+	write_SSDR(*(u32 *)(drv_data->tx), reg);
+	drv_data->tx += 4;
+
+	return 1;
+}
+
+static int u32_reader(struct driver_data *drv_data)
+{
+	void __iomem *reg = drv_data->ioaddr;
+
+	while ((read_SSSR(reg) & SSSR_RNE)
+		&& (drv_data->rx < drv_data->rx_end)) {
+		*(u32 *)(drv_data->rx) = read_SSDR(reg);
+		drv_data->rx += 4;
+	}
+
+	return drv_data->rx == drv_data->rx_end;
+}
+
+static void *next_transfer(struct driver_data *drv_data)
+{
+	struct spi_message *msg = drv_data->cur_msg;
+	struct spi_transfer *trans = drv_data->cur_transfer;
+
+	/* Move to next transfer */
+	if (trans->transfer_list.next != &msg->transfers) {
+		drv_data->cur_transfer =
+			list_entry(trans->transfer_list.next,
+					struct spi_transfer,
+					transfer_list);
+		return RUNNING_STATE;
+	} else
+		return DONE_STATE;
+}
+
+static int map_dma_buffers(struct driver_data *drv_data)
+{
+	struct spi_message *msg = drv_data->cur_msg;
+	struct device *dev = &msg->spi->dev;
+
+	if (!drv_data->cur_chip->enable_dma)
+		return 0;
+
+	if (msg->is_dma_mapped)
+		return  drv_data->rx_dma && drv_data->tx_dma;
+
+	if (!IS_DMA_ALIGNED(drv_data->rx) || !IS_DMA_ALIGNED(drv_data->tx))
+		return 0;
+
+	/* Modify setup if rx buffer is null */
+	if (drv_data->rx == NULL) {
+		*drv_data->null_dma_buf = 0;
+		drv_data->rx = drv_data->null_dma_buf;
+		drv_data->rx_map_len = 4;
+	} else
+		drv_data->rx_map_len = drv_data->len;
+
+
+	/* Modify setup if tx buffer is null */
+	if (drv_data->tx == NULL) {
+		*drv_data->null_dma_buf = 0;
+		drv_data->tx = drv_data->null_dma_buf;
+		drv_data->tx_map_len = 4;
+	} else
+		drv_data->tx_map_len = drv_data->len;
+
+	/* Stream map the tx buffer. Always do DMA_TO_DEVICE first
+	 * so we flush the cache *before* invalidating it, in case
+	 * the tx and rx buffers overlap.
+	 */
+	drv_data->tx_dma = dma_map_single(dev, drv_data->tx,
+					drv_data->tx_map_len, DMA_TO_DEVICE);
+	if (dma_mapping_error(dev, drv_data->tx_dma))
+		return 0;
+
+	/* Stream map the rx buffer */
+	drv_data->rx_dma = dma_map_single(dev, drv_data->rx,
+					drv_data->rx_map_len, DMA_FROM_DEVICE);
+	if (dma_mapping_error(dev, drv_data->rx_dma)) {
+		dma_unmap_single(dev, drv_data->tx_dma,
+					drv_data->tx_map_len, DMA_TO_DEVICE);
+		return 0;
+	}
+
+	return 1;
+}
+
+static void unmap_dma_buffers(struct driver_data *drv_data)
+{
+	struct device *dev;
+
+	if (!drv_data->dma_mapped)
+		return;
+
+	if (!drv_data->cur_msg->is_dma_mapped) {
+		dev = &drv_data->cur_msg->spi->dev;
+		dma_unmap_single(dev, drv_data->rx_dma,
+					drv_data->rx_map_len, DMA_FROM_DEVICE);
+		dma_unmap_single(dev, drv_data->tx_dma,
+					drv_data->tx_map_len, DMA_TO_DEVICE);
+	}
+
+	drv_data->dma_mapped = 0;
+}
+
+/* caller already set message->status; dma and pio irqs are blocked */
+static void giveback(struct driver_data *drv_data)
+{
+	struct spi_transfer* last_transfer;
+	unsigned long flags;
+	struct spi_message *msg;
+
+	spin_lock_irqsave(&drv_data->lock, flags);
+	msg = drv_data->cur_msg;
+	drv_data->cur_msg = NULL;
+	drv_data->cur_transfer = NULL;
+	queue_work(drv_data->workqueue, &drv_data->pump_messages);
+	spin_unlock_irqrestore(&drv_data->lock, flags);
+
+	last_transfer = list_entry(msg->transfers.prev,
+					struct spi_transfer,
+					transfer_list);
+
+	/* Delay if requested before any change in chip select */
+	if (last_transfer->delay_usecs)
+		udelay(last_transfer->delay_usecs);
+
+	/* Drop chip select UNLESS cs_change is true or we are returning
+	 * a message with an error, or next message is for another chip
+	 */
+	if (!last_transfer->cs_change)
+		cs_deassert(drv_data);
+	else {
+		struct spi_message *next_msg;
+
+		/* Holding of cs was hinted, but we need to make sure
+		 * the next message is for the same chip.  Don't waste
+		 * time with the following tests unless this was hinted.
+		 *
+		 * We cannot postpone this until pump_messages, because
+		 * after calling msg->complete (below) the driver that
+		 * sent the current message could be unloaded, which
+		 * could invalidate the cs_control() callback...
+		 */
+
+		/* get a pointer to the next message, if any */
+		spin_lock_irqsave(&drv_data->lock, flags);
+		if (list_empty(&drv_data->queue))
+			next_msg = NULL;
+		else
+			next_msg = list_entry(drv_data->queue.next,
+					struct spi_message, queue);
+		spin_unlock_irqrestore(&drv_data->lock, flags);
+
+		/* see if the next and current messages point
+		 * to the same chip
+		 */
+		if (next_msg && next_msg->spi != msg->spi)
+			next_msg = NULL;
+		if (!next_msg || msg->state == ERROR_STATE)
+			cs_deassert(drv_data);
+	}
+
+	msg->state = NULL;
+	if (msg->complete)
+		msg->complete(msg->context);
+
+	drv_data->cur_chip = NULL;
+}
+
+static int wait_ssp_rx_stall(void const __iomem *ioaddr)
+{
+	unsigned long limit = loops_per_jiffy << 1;
+
+	while ((read_SSSR(ioaddr) & SSSR_BSY) && --limit)
+		cpu_relax();
+
+	return limit;
+}
+
+static int wait_dma_channel_stop(int channel)
+{
+	unsigned long limit = loops_per_jiffy << 1;
+
+	while (!(DCSR(channel) & DCSR_STOPSTATE) && --limit)
+		cpu_relax();
+
+	return limit;
+}
+
+static void dma_error_stop(struct driver_data *drv_data, const char *msg)
+{
+	void __iomem *reg = drv_data->ioaddr;
+
+	/* Stop and reset */
+	DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
+	DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
+	write_SSSR_CS(drv_data, drv_data->clear_sr);
+	write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg);
+	if (!pxa25x_ssp_comp(drv_data))
+		write_SSTO(0, reg);
+	flush(drv_data);
+	write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
+
+	unmap_dma_buffers(drv_data);
+
+	dev_err(&drv_data->pdev->dev, "%s\n", msg);
+
+	drv_data->cur_msg->state = ERROR_STATE;
+	tasklet_schedule(&drv_data->pump_transfers);
+}
+
+static void dma_transfer_complete(struct driver_data *drv_data)
+{
+	void __iomem *reg = drv_data->ioaddr;
+	struct spi_message *msg = drv_data->cur_msg;
+
+	/* Clear and disable interrupts on SSP and DMA channels*/
+	write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg);
+	write_SSSR_CS(drv_data, drv_data->clear_sr);
+	DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
+	DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
+
+	if (wait_dma_channel_stop(drv_data->rx_channel) == 0)
+		dev_err(&drv_data->pdev->dev,
+			"dma_handler: dma rx channel stop failed\n");
+
+	if (wait_ssp_rx_stall(drv_data->ioaddr) == 0)
+		dev_err(&drv_data->pdev->dev,
+			"dma_transfer: ssp rx stall failed\n");
+
+	unmap_dma_buffers(drv_data);
+
+	/* update the buffer pointer for the amount completed in dma */
+	drv_data->rx += drv_data->len -
+			(DCMD(drv_data->rx_channel) & DCMD_LENGTH);
+
+	/* read trailing data from fifo, it does not matter how many
+	 * bytes are in the fifo just read until buffer is full
+	 * or fifo is empty, which ever occurs first */
+	drv_data->read(drv_data);
+
+	/* return count of what was actually read */
+	msg->actual_length += drv_data->len -
+				(drv_data->rx_end - drv_data->rx);
+
+	/* Transfer delays and chip select release are
+	 * handled in pump_transfers or giveback
+	 */
+
+	/* Move to next transfer */
+	msg->state = next_transfer(drv_data);
+
+	/* Schedule transfer tasklet */
+	tasklet_schedule(&drv_data->pump_transfers);
+}
+
+static void dma_handler(int channel, void *data)
+{
+	struct driver_data *drv_data = data;
+	u32 irq_status = DCSR(channel) & DMA_INT_MASK;
+
+	if (irq_status & DCSR_BUSERR) {
+
+		if (channel == drv_data->tx_channel)
+			dma_error_stop(drv_data,
+					"dma_handler: "
+					"bad bus address on tx channel");
+		else
+			dma_error_stop(drv_data,
+					"dma_handler: "
+					"bad bus address on rx channel");
+		return;
+	}
+
+	/* PXA255x_SSP has no timeout interrupt, wait for tailing bytes */
+	if ((channel == drv_data->tx_channel)
+		&& (irq_status & DCSR_ENDINTR)
+		&& (drv_data->ssp_type == PXA25x_SSP)) {
+
+		/* Wait for rx to stall */
+		if (wait_ssp_rx_stall(drv_data->ioaddr) == 0)
+			dev_err(&drv_data->pdev->dev,
+				"dma_handler: ssp rx stall failed\n");
+
+		/* finish this transfer, start the next */
+		dma_transfer_complete(drv_data);
+	}
+}
+
+static irqreturn_t dma_transfer(struct driver_data *drv_data)
+{
+	u32 irq_status;
+	void __iomem *reg = drv_data->ioaddr;
+
+	irq_status = read_SSSR(reg) & drv_data->mask_sr;
+	if (irq_status & SSSR_ROR) {
+		dma_error_stop(drv_data, "dma_transfer: fifo overrun");
+		return IRQ_HANDLED;
+	}
+
+	/* Check for false positive timeout */
+	if ((irq_status & SSSR_TINT)
+		&& (DCSR(drv_data->tx_channel) & DCSR_RUN)) {
+		write_SSSR(SSSR_TINT, reg);
+		return IRQ_HANDLED;
+	}
+
+	if (irq_status & SSSR_TINT || drv_data->rx == drv_data->rx_end) {
+
+		/* Clear and disable timeout interrupt, do the rest in
+		 * dma_transfer_complete */
+		if (!pxa25x_ssp_comp(drv_data))
+			write_SSTO(0, reg);
+
+		/* finish this transfer, start the next */
+		dma_transfer_complete(drv_data);
+
+		return IRQ_HANDLED;
+	}
+
+	/* Opps problem detected */
+	return IRQ_NONE;
+}
+
+static void reset_sccr1(struct driver_data *drv_data)
+{
+	void __iomem *reg = drv_data->ioaddr;
+	struct chip_data *chip = drv_data->cur_chip;
+	u32 sccr1_reg;
+
+	sccr1_reg = read_SSCR1(reg) & ~drv_data->int_cr1;
+	sccr1_reg &= ~SSCR1_RFT;
+	sccr1_reg |= chip->threshold;
+	write_SSCR1(sccr1_reg, reg);
+}
+
+static void int_error_stop(struct driver_data *drv_data, const char* msg)
+{
+	void __iomem *reg = drv_data->ioaddr;
+
+	/* Stop and reset SSP */
+	write_SSSR_CS(drv_data, drv_data->clear_sr);
+	reset_sccr1(drv_data);
+	if (!pxa25x_ssp_comp(drv_data))
+		write_SSTO(0, reg);
+	flush(drv_data);
+	write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
+
+	dev_err(&drv_data->pdev->dev, "%s\n", msg);
+
+	drv_data->cur_msg->state = ERROR_STATE;
+	tasklet_schedule(&drv_data->pump_transfers);
+}
+
+static void int_transfer_complete(struct driver_data *drv_data)
+{
+	void __iomem *reg = drv_data->ioaddr;
+
+	/* Stop SSP */
+	write_SSSR_CS(drv_data, drv_data->clear_sr);
+	reset_sccr1(drv_data);
+	if (!pxa25x_ssp_comp(drv_data))
+		write_SSTO(0, reg);
+
+	/* Update total byte transferred return count actual bytes read */
+	drv_data->cur_msg->actual_length += drv_data->len -
+				(drv_data->rx_end - drv_data->rx);
+
+	/* Transfer delays and chip select release are
+	 * handled in pump_transfers or giveback
+	 */
+
+	/* Move to next transfer */
+	drv_data->cur_msg->state = next_transfer(drv_data);
+
+	/* Schedule transfer tasklet */
+	tasklet_schedule(&drv_data->pump_transfers);
+}
+
+static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
+{
+	void __iomem *reg = drv_data->ioaddr;
+
+	u32 irq_mask = (read_SSCR1(reg) & SSCR1_TIE) ?
+			drv_data->mask_sr : drv_data->mask_sr & ~SSSR_TFS;
+
+	u32 irq_status = read_SSSR(reg) & irq_mask;
+
+	if (irq_status & SSSR_ROR) {
+		int_error_stop(drv_data, "interrupt_transfer: fifo overrun");
+		return IRQ_HANDLED;
+	}
+
+	if (irq_status & SSSR_TINT) {
+		write_SSSR(SSSR_TINT, reg);
+		if (drv_data->read(drv_data)) {
+			int_transfer_complete(drv_data);
+			return IRQ_HANDLED;
+		}
+	}
+
+	/* Drain rx fifo, Fill tx fifo and prevent overruns */
+	do {
+		if (drv_data->read(drv_data)) {
+			int_transfer_complete(drv_data);
+			return IRQ_HANDLED;
+		}
+	} while (drv_data->write(drv_data));
+
+	if (drv_data->read(drv_data)) {
+		int_transfer_complete(drv_data);
+		return IRQ_HANDLED;
+	}
+
+	if (drv_data->tx == drv_data->tx_end) {
+		u32 bytes_left;
+		u32 sccr1_reg;
+
+		sccr1_reg = read_SSCR1(reg);
+		sccr1_reg &= ~SSCR1_TIE;
+
+		/*
+		 * PXA25x_SSP has no timeout, set up rx threshould for the
+		 * remaining RX bytes.
+		 */
+		if (pxa25x_ssp_comp(drv_data)) {
+
+			sccr1_reg &= ~SSCR1_RFT;
+
+			bytes_left = drv_data->rx_end - drv_data->rx;
+			switch (drv_data->n_bytes) {
+			case 4:
+				bytes_left >>= 1;
+			case 2:
+				bytes_left >>= 1;
+			}
+
+			if (bytes_left > RX_THRESH_DFLT)
+				bytes_left = RX_THRESH_DFLT;
+
+			sccr1_reg |= SSCR1_RxTresh(bytes_left);
+		}
+		write_SSCR1(sccr1_reg, reg);
+	}
+
+	/* We did something */
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t ssp_int(int irq, void *dev_id)
+{
+	struct driver_data *drv_data = dev_id;
+	void __iomem *reg = drv_data->ioaddr;
+	u32 sccr1_reg = read_SSCR1(reg);
+	u32 mask = drv_data->mask_sr;
+	u32 status;
+
+	status = read_SSSR(reg);
+
+	/* Ignore possible writes if we don't need to write */
+	if (!(sccr1_reg & SSCR1_TIE))
+		mask &= ~SSSR_TFS;
+
+	if (!(status & mask))
+		return IRQ_NONE;
+
+	if (!drv_data->cur_msg) {
+
+		write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
+		write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg);
+		if (!pxa25x_ssp_comp(drv_data))
+			write_SSTO(0, reg);
+		write_SSSR_CS(drv_data, drv_data->clear_sr);
+
+		dev_err(&drv_data->pdev->dev, "bad message state "
+			"in interrupt handler\n");
+
+		/* Never fail */
+		return IRQ_HANDLED;
+	}
+
+	return drv_data->transfer_handler(drv_data);
+}
+
+static int set_dma_burst_and_threshold(struct chip_data *chip,
+				struct spi_device *spi,
+				u8 bits_per_word, u32 *burst_code,
+				u32 *threshold)
+{
+	struct pxa2xx_spi_chip *chip_info =
+			(struct pxa2xx_spi_chip *)spi->controller_data;
+	int bytes_per_word;
+	int burst_bytes;
+	int thresh_words;
+	int req_burst_size;
+	int retval = 0;
+
+	/* Set the threshold (in registers) to equal the same amount of data
+	 * as represented by burst size (in bytes).  The computation below
+	 * is (burst_size rounded up to nearest 8 byte, word or long word)
+	 * divided by (bytes/register); the tx threshold is the inverse of
+	 * the rx, so that there will always be enough data in the rx fifo
+	 * to satisfy a burst, and there will always be enough space in the
+	 * tx fifo to accept a burst (a tx burst will overwrite the fifo if
+	 * there is not enough space), there must always remain enough empty
+	 * space in the rx fifo for any data loaded to the tx fifo.
+	 * Whenever burst_size (in bytes) equals bits/word, the fifo threshold
+	 * will be 8, or half the fifo;
+	 * The threshold can only be set to 2, 4 or 8, but not 16, because
+	 * to burst 16 to the tx fifo, the fifo would have to be empty;
+	 * however, the minimum fifo trigger level is 1, and the tx will
+	 * request service when the fifo is at this level, with only 15 spaces.
+	 */
+
+	/* find bytes/word */
+	if (bits_per_word <= 8)
+		bytes_per_word = 1;
+	else if (bits_per_word <= 16)
+		bytes_per_word = 2;
+	else
+		bytes_per_word = 4;
+
+	/* use struct pxa2xx_spi_chip->dma_burst_size if available */
+	if (chip_info)
+		req_burst_size = chip_info->dma_burst_size;
+	else {
+		switch (chip->dma_burst_size) {
+		default:
+			/* if the default burst size is not set,
+			 * do it now */
+			chip->dma_burst_size = DCMD_BURST8;
+		case DCMD_BURST8:
+			req_burst_size = 8;
+			break;
+		case DCMD_BURST16:
+			req_burst_size = 16;
+			break;
+		case DCMD_BURST32:
+			req_burst_size = 32;
+			break;
+		}
+	}
+	if (req_burst_size <= 8) {
+		*burst_code = DCMD_BURST8;
+		burst_bytes = 8;
+	} else if (req_burst_size <= 16) {
+		if (bytes_per_word == 1) {
+			/* don't burst more than 1/2 the fifo */
+			*burst_code = DCMD_BURST8;
+			burst_bytes = 8;
+			retval = 1;
+		} else {
+			*burst_code = DCMD_BURST16;
+			burst_bytes = 16;
+		}
+	} else {
+		if (bytes_per_word == 1) {
+			/* don't burst more than 1/2 the fifo */
+			*burst_code = DCMD_BURST8;
+			burst_bytes = 8;
+			retval = 1;
+		} else if (bytes_per_word == 2) {
+			/* don't burst more than 1/2 the fifo */
+			*burst_code = DCMD_BURST16;
+			burst_bytes = 16;
+			retval = 1;
+		} else {
+			*burst_code = DCMD_BURST32;
+			burst_bytes = 32;
+		}
+	}
+
+	thresh_words = burst_bytes / bytes_per_word;
+
+	/* thresh_words will be between 2 and 8 */
+	*threshold = (SSCR1_RxTresh(thresh_words) & SSCR1_RFT)
+			| (SSCR1_TxTresh(16-thresh_words) & SSCR1_TFT);
+
+	return retval;
+}
+
+static unsigned int ssp_get_clk_div(struct ssp_device *ssp, int rate)
+{
+	unsigned long ssp_clk = clk_get_rate(ssp->clk);
+
+	if (ssp->type == PXA25x_SSP || ssp->type == CE4100_SSP)
+		return ((ssp_clk / (2 * rate) - 1) & 0xff) << 8;
+	else
+		return ((ssp_clk / rate - 1) & 0xfff) << 8;
+}
+
+static void pump_transfers(unsigned long data)
+{
+	struct driver_data *drv_data = (struct driver_data *)data;
+	struct spi_message *message = NULL;
+	struct spi_transfer *transfer = NULL;
+	struct spi_transfer *previous = NULL;
+	struct chip_data *chip = NULL;
+	struct ssp_device *ssp = drv_data->ssp;
+	void __iomem *reg = drv_data->ioaddr;
+	u32 clk_div = 0;
+	u8 bits = 0;
+	u32 speed = 0;
+	u32 cr0;
+	u32 cr1;
+	u32 dma_thresh = drv_data->cur_chip->dma_threshold;
+	u32 dma_burst = drv_data->cur_chip->dma_burst_size;
+
+	/* Get current state information */
+	message = drv_data->cur_msg;
+	transfer = drv_data->cur_transfer;
+	chip = drv_data->cur_chip;
+
+	/* Handle for abort */
+	if (message->state == ERROR_STATE) {
+		message->status = -EIO;
+		giveback(drv_data);
+		return;
+	}
+
+	/* Handle end of message */
+	if (message->state == DONE_STATE) {
+		message->status = 0;
+		giveback(drv_data);
+		return;
+	}
+
+	/* Delay if requested at end of transfer before CS change */
+	if (message->state == RUNNING_STATE) {
+		previous = list_entry(transfer->transfer_list.prev,
+					struct spi_transfer,
+					transfer_list);
+		if (previous->delay_usecs)
+			udelay(previous->delay_usecs);
+
+		/* Drop chip select only if cs_change is requested */
+		if (previous->cs_change)
+			cs_deassert(drv_data);
+	}
+
+	/* Check for transfers that need multiple DMA segments */
+	if (transfer->len > MAX_DMA_LEN && chip->enable_dma) {
+
+		/* reject already-mapped transfers; PIO won't always work */
+		if (message->is_dma_mapped
+				|| transfer->rx_dma || transfer->tx_dma) {
+			dev_err(&drv_data->pdev->dev,
+				"pump_transfers: mapped transfer length "
+				"of %u is greater than %d\n",
+				transfer->len, MAX_DMA_LEN);
+			message->status = -EINVAL;
+			giveback(drv_data);
+			return;
+		}
+
+		/* warn ... we force this to PIO mode */
+		if (printk_ratelimit())
+			dev_warn(&message->spi->dev, "pump_transfers: "
+				"DMA disabled for transfer length %ld "
+				"greater than %d\n",
+				(long)drv_data->len, MAX_DMA_LEN);
+	}
+
+	/* Setup the transfer state based on the type of transfer */
+	if (flush(drv_data) == 0) {
+		dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n");
+		message->status = -EIO;
+		giveback(drv_data);
+		return;
+	}
+	drv_data->n_bytes = chip->n_bytes;
+	drv_data->dma_width = chip->dma_width;
+	drv_data->tx = (void *)transfer->tx_buf;
+	drv_data->tx_end = drv_data->tx + transfer->len;
+	drv_data->rx = transfer->rx_buf;
+	drv_data->rx_end = drv_data->rx + transfer->len;
+	drv_data->rx_dma = transfer->rx_dma;
+	drv_data->tx_dma = transfer->tx_dma;
+	drv_data->len = transfer->len & DCMD_LENGTH;
+	drv_data->write = drv_data->tx ? chip->write : null_writer;
+	drv_data->read = drv_data->rx ? chip->read : null_reader;
+
+	/* Change speed and bit per word on a per transfer */
+	cr0 = chip->cr0;
+	if (transfer->speed_hz || transfer->bits_per_word) {
+
+		bits = chip->bits_per_word;
+		speed = chip->speed_hz;
+
+		if (transfer->speed_hz)
+			speed = transfer->speed_hz;
+
+		if (transfer->bits_per_word)
+			bits = transfer->bits_per_word;
+
+		clk_div = ssp_get_clk_div(ssp, speed);
+
+		if (bits <= 8) {
+			drv_data->n_bytes = 1;
+			drv_data->dma_width = DCMD_WIDTH1;
+			drv_data->read = drv_data->read != null_reader ?
+						u8_reader : null_reader;
+			drv_data->write = drv_data->write != null_writer ?
+						u8_writer : null_writer;
+		} else if (bits <= 16) {
+			drv_data->n_bytes = 2;
+			drv_data->dma_width = DCMD_WIDTH2;
+			drv_data->read = drv_data->read != null_reader ?
+						u16_reader : null_reader;
+			drv_data->write = drv_data->write != null_writer ?
+						u16_writer : null_writer;
+		} else if (bits <= 32) {
+			drv_data->n_bytes = 4;
+			drv_data->dma_width = DCMD_WIDTH4;
+			drv_data->read = drv_data->read != null_reader ?
+						u32_reader : null_reader;
+			drv_data->write = drv_data->write != null_writer ?
+						u32_writer : null_writer;
+		}
+		/* if bits/word is changed in dma mode, then must check the
+		 * thresholds and burst also */
+		if (chip->enable_dma) {
+			if (set_dma_burst_and_threshold(chip, message->spi,
+							bits, &dma_burst,
+							&dma_thresh))
+				if (printk_ratelimit())
+					dev_warn(&message->spi->dev,
+						"pump_transfers: "
+						"DMA burst size reduced to "
+						"match bits_per_word\n");
+		}
+
+		cr0 = clk_div
+			| SSCR0_Motorola
+			| SSCR0_DataSize(bits > 16 ? bits - 16 : bits)
+			| SSCR0_SSE
+			| (bits > 16 ? SSCR0_EDSS : 0);
+	}
+
+	message->state = RUNNING_STATE;
+
+	/* Try to map dma buffer and do a dma transfer if successful, but
+	 * only if the length is non-zero and less than MAX_DMA_LEN.
+	 *
+	 * Zero-length non-descriptor DMA is illegal on PXA2xx; force use
+	 * of PIO instead.  Care is needed above because the transfer may
+	 * have have been passed with buffers that are already dma mapped.
+	 * A zero-length transfer in PIO mode will not try to write/read
+	 * to/from the buffers
+	 *
+	 * REVISIT large transfers are exactly where we most want to be
+	 * using DMA.  If this happens much, split those transfers into
+	 * multiple DMA segments rather than forcing PIO.
+	 */
+	drv_data->dma_mapped = 0;
+	if (drv_data->len > 0 && drv_data->len <= MAX_DMA_LEN)
+		drv_data->dma_mapped = map_dma_buffers(drv_data);
+	if (drv_data->dma_mapped) {
+
+		/* Ensure we have the correct interrupt handler */
+		drv_data->transfer_handler = dma_transfer;
+
+		/* Setup rx DMA Channel */
+		DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
+		DSADR(drv_data->rx_channel) = drv_data->ssdr_physical;
+		DTADR(drv_data->rx_channel) = drv_data->rx_dma;
+		if (drv_data->rx == drv_data->null_dma_buf)
+			/* No target address increment */
+			DCMD(drv_data->rx_channel) = DCMD_FLOWSRC
+							| drv_data->dma_width
+							| dma_burst
+							| drv_data->len;
+		else
+			DCMD(drv_data->rx_channel) = DCMD_INCTRGADDR
+							| DCMD_FLOWSRC
+							| drv_data->dma_width
+							| dma_burst
+							| drv_data->len;
+
+		/* Setup tx DMA Channel */
+		DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
+		DSADR(drv_data->tx_channel) = drv_data->tx_dma;
+		DTADR(drv_data->tx_channel) = drv_data->ssdr_physical;
+		if (drv_data->tx == drv_data->null_dma_buf)
+			/* No source address increment */
+			DCMD(drv_data->tx_channel) = DCMD_FLOWTRG
+							| drv_data->dma_width
+							| dma_burst
+							| drv_data->len;
+		else
+			DCMD(drv_data->tx_channel) = DCMD_INCSRCADDR
+							| DCMD_FLOWTRG
+							| drv_data->dma_width
+							| dma_burst
+							| drv_data->len;
+
+		/* Enable dma end irqs on SSP to detect end of transfer */
+		if (drv_data->ssp_type == PXA25x_SSP)
+			DCMD(drv_data->tx_channel) |= DCMD_ENDIRQEN;
+
+		/* Clear status and start DMA engine */
+		cr1 = chip->cr1 | dma_thresh | drv_data->dma_cr1;
+		write_SSSR(drv_data->clear_sr, reg);
+		DCSR(drv_data->rx_channel) |= DCSR_RUN;
+		DCSR(drv_data->tx_channel) |= DCSR_RUN;