[PATCH RESEND] intel_mid_ssp_spi: Moorestown and Medfield SPI for SSP devices

[Alan Cox <alan-qBU/x9rampVanCEyBjwyrvXRex20P6io@public.gmane.org>]

From: Mathieu SOULARD <mathieux.soulard-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>

This driver is a fusion of various internal drivers into a single
driver for the SPI slave/master on the Intel Moorestown and Medfield
SSP devices.

Signed-off-by: Mathieu SOULARD <mathieux.soulard-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
[Queueing and runtime pm added]
Signed-off-by: Kristen Carlson Accardi <kristen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
[Ported to the -next tree DMA engine]
Signed-off-by: Alan Cox <alan-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
---

 drivers/spi/Kconfig             |    8 
 drivers/spi/Makefile            |    2 
 drivers/spi/spi-intel-mid-ssp.c | 1426 +++++++++++++++++++++++++++++++++++++++
 drivers/spi/spi-intel-mid-ssp.h |  308 ++++++++
 4 files changed, 1743 insertions(+), 1 deletions(-)
 create mode 100644 drivers/spi/spi-intel-mid-ssp.c
 create mode 100644 drivers/spi/spi-intel-mid-ssp.h


diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 8293658..90b7ef6 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -163,6 +163,14 @@ config SPI_IMX
 	  This enables using the Freescale i.MX SPI controllers in master
 	  mode.
 
+config SPI_INTEL_MID_SSP
+	tristate "SSP SPI controller driver for Intel MID platforms (EXPERIMENTAL)"
+	depends on SPI_MASTER && INTEL_MID_DMAC && EXPERIMENTAL
+	help
+	  This is the unified SSP SPI slave controller driver for the Intel
+	  MID platforms, handling Moorestown & Medfield, master & slave
+	  clock mode.
+
 config SPI_LM70_LLP
 	tristate "Parallel port adapter for LM70 eval board (DEVELOPMENT)"
 	depends on PARPORT && EXPERIMENTAL
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 61c3261..e81757a 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -58,4 +58,4 @@ obj-$(CONFIG_SPI_TLE62X0)		+= spi-tle62x0.o
 obj-$(CONFIG_SPI_TOPCLIFF_PCH)		+= spi-topcliff-pch.o
 obj-$(CONFIG_SPI_TXX9)			+= spi-txx9.o
 obj-$(CONFIG_SPI_XILINX)		+= spi-xilinx.o
-
+obj-$(CONFIG_SPI_INTEL_MID_SSP)		+= spi-intel-mid-ssp.o
diff --git a/drivers/spi/spi-intel-mid-ssp.c b/drivers/spi/spi-intel-mid-ssp.c
new file mode 100644
index 0000000..77bff9f
--- /dev/null
+++ b/drivers/spi/spi-intel-mid-ssp.c
@@ -0,0 +1,1426 @@
+/*
+ * This driver supports Bulverde SSP core used on Intel MID platforms
+ * It supports the SSP of Medfield platforms and handles clock
+ * slave & master modes.
+ *
+ * Copyright (c) 2010, Intel Corporation.
+ *  Ken Mills <ken.k.mills-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
+ *  Sylvain Centelles <sylvain.centelles-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
+ *  Mathieu SOULARD
+ *  Kristen Carlson Accardi <kristen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
+ *  Alan Cox <alan-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+/*
+ * Note:
+ *
+ * Supports DMA and non-interrupt polled transfers.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/highmem.h>
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/dma-mapping.h>
+#include <linux/intel_mid_dma.h>
+#include <linux/pm_qos.h>
+#include <linux/pm_runtime.h>
+
+#include <linux/spi/spi.h>
+#include "spi-intel-mid-ssp.h"
+
+#define DRIVER_NAME "spi-intel-mid-ssp"
+
+MODULE_AUTHOR("Ken Mills");
+MODULE_DESCRIPTION("Bulverde SSP core SPI contoller");
+MODULE_LICENSE("GPL");
+
+static const struct pci_device_id pci_ids[];
+
+#ifdef DUMP_RX
+static void dump_trailer(const struct device *dev, char *buf, int len, int sz)
+{
+	int tlen1 = (len < sz ? len : sz);
+	int tlen2 =  ((len - sz) > sz) ? sz : (len - sz);
+	unsigned char *p;
+	static char msg[MAX_SPI_TRANSFER_SIZE];
+
+	memset(msg, '\0', sizeof(msg));
+	p = buf;
+	while (p < buf + tlen1)
+		sprintf(msg, "%s%02x", msg, (unsigned int)*p++);
+
+	if (tlen2 > 0) {
+		sprintf(msg, "%s .....", msg);
+		p = (buf+len) - tlen2;
+		while (p < buf + len)
+			sprintf(msg, "%s%02x", msg, (unsigned int)*p++);
+	}
+
+	dev_info(dev, "DUMP: %p[0:%d ... %d:%d]:%s", buf, tlen1 - 1,
+		   len-tlen2, len - 1, msg);
+}
+#endif
+
+static inline u32 is_tx_fifo_empty(struct ssp_driver_context *drv_context)
+{
+	u32 sssr;
+	sssr = read_SSSR(drv_context->ioaddr);
+	if ((sssr & SSSR_TFL_MASK) || (sssr & SSSR_TNF) == 0)
+		return 0;
+	else
+		return 1;
+}
+
+static inline u32 is_rx_fifo_empty(struct ssp_driver_context *drv_context)
+{
+	return ((read_SSSR(drv_context->ioaddr) & SSSR_RNE) == 0);
+}
+
+static inline void disable_interface(struct ssp_driver_context *drv_context)
+{
+	void *reg = drv_context->ioaddr;
+	write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
+}
+
+static inline void disable_triggers(struct ssp_driver_context *drv_context)
+{
+	void *reg = drv_context->ioaddr;
+	write_SSCR1(read_SSCR1(reg) & ~drv_context->cr1_sig, reg);
+}
+
+
+static void flush(struct ssp_driver_context *drv_context)
+{
+	void *reg = drv_context->ioaddr;
+	u32 i = 0;
+
+	/* If the transmit fifo is not empty, reset the interface. */
+	if (!is_tx_fifo_empty(drv_context)) {
+		dev_err(&drv_context->pdev->dev,
+				"TX FIFO not empty. Reset of SPI IF");
+		disable_interface(drv_context);
+		return;
+	}
+
+	dev_dbg(&drv_context->pdev->dev, " SSSR=%x\r\n", read_SSSR(reg));
+	while (!is_rx_fifo_empty(drv_context) && (i < SPI_FIFO_SIZE + 1)) {
+		read_SSDR(reg);
+		i++;
+	}
+	WARN(i > 0, "%d words flush occured\n", i);
+
+	return;
+}
+
+static int null_writer(struct ssp_driver_context *drv_context)
+{
+	void *reg = drv_context->ioaddr;
+	u8 n_bytes = drv_context->n_bytes;
+
+	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
+		|| (drv_context->tx == drv_context->tx_end))
+		return 0;
+
+	write_SSDR(0, reg);
+	drv_context->tx += n_bytes;
+
+	return 1;
+}
+
+static int null_reader(struct ssp_driver_context *drv_context)
+{
+	void *reg = drv_context->ioaddr;
+	u8 n_bytes = drv_context->n_bytes;
+
+	while ((read_SSSR(reg) & SSSR_RNE)
+		&& (drv_context->rx < drv_context->rx_end)) {
+		read_SSDR(reg);
+		drv_context->rx += n_bytes;
+	}
+
+	return drv_context->rx == drv_context->rx_end;
+}
+
+static int u8_writer(struct ssp_driver_context *drv_context)
+{
+	void *reg = drv_context->ioaddr;
+	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
+		|| (drv_context->tx == drv_context->tx_end))
+		return 0;
+
+	write_SSDR(*(u8 *)(drv_context->tx), reg);
+	++drv_context->tx;
+
+	return 1;
+}
+
+static int u8_reader(struct ssp_driver_context *drv_context)
+{
+	void *reg = drv_context->ioaddr;
+	while ((read_SSSR(reg) & SSSR_RNE)
+		&& (drv_context->rx < drv_context->rx_end)) {
+		*(u8 *)(drv_context->rx) = read_SSDR(reg);
+		++drv_context->rx;
+	}
+
+	return drv_context->rx == drv_context->rx_end;
+}
+
+static int u16_writer(struct ssp_driver_context *drv_context)
+{
+	void *reg = drv_context->ioaddr;
+	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
+		|| (drv_context->tx == drv_context->tx_end))
+		return 0;
+
+	write_SSDR(*(u16 *)(drv_context->tx), reg);
+	drv_context->tx += 2;
+
+	return 1;
+}
+
+static int u16_reader(struct ssp_driver_context *drv_context)
+{
+	void *reg = drv_context->ioaddr;
+	while ((read_SSSR(reg) & SSSR_RNE)
+		&& (drv_context->rx < drv_context->rx_end)) {
+		*(u16 *)(drv_context->rx) = read_SSDR(reg);
+		drv_context->rx += 2;
+	}
+
+	return drv_context->rx == drv_context->rx_end;
+}
+
+static int u32_writer(struct ssp_driver_context *drv_context)
+{
+	void *reg = drv_context->ioaddr;
+	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
+		|| (drv_context->tx == drv_context->tx_end))
+		return 0;
+
+	write_SSDR(*(u32 *)(drv_context->tx), reg);
+	drv_context->tx += 4;
+
+	return 1;
+}
+
+static int u32_reader(struct ssp_driver_context *drv_context)
+{
+	void *reg = drv_context->ioaddr;
+	while ((read_SSSR(reg) & SSSR_RNE)
+		&& (drv_context->rx < drv_context->rx_end)) {
+		*(u32 *)(drv_context->rx) = read_SSDR(reg);
+		drv_context->rx += 4;
+	}
+
+	return drv_context->rx == drv_context->rx_end;
+}
+
+static bool chan_filter(struct dma_chan *chan, void *param)
+{
+	struct ssp_driver_context *drv_context =
+		(struct ssp_driver_context *)param;
+	bool ret = false;
+
+	if (!drv_context->dmac1)
+		return ret;
+
+	if (chan->device->dev == &drv_context->dmac1->dev)
+		ret = true;
+
+	return ret;
+}
+
+/**
+ * unmap_dma_buffers() - Unmap the DMA buffers used during the last transfer.
+ * @drv_context:	Pointer to the private driver context
+ */
+static void unmap_dma_buffers(struct ssp_driver_context *drv_context)
+{
+	struct device *dev = &drv_context->pdev->dev;
+
+	if (!drv_context->dma_mapped)
+		return;
+	dma_unmap_single(dev, drv_context->rx_dma, drv_context->len,
+		PCI_DMA_FROMDEVICE);
+	dma_unmap_single(dev, drv_context->tx_dma, drv_context->len,
+		PCI_DMA_TODEVICE);
+	drv_context->dma_mapped = 0;
+}
+
+/**
+ * intel_mid_ssp_spi_dma_done() - End of DMA transfer callback
+ * @arg:	Pointer to the data provided at callback registration
+ *
+ * This function is set as callback for both RX and TX DMA transfers. The
+ * RX or TX 'done' flag is set acording to the direction of the ended
+ * transfer. Then, if both RX and TX flags are set, it means that the
+ * transfer job is completed.
+ */
+static void intel_mid_ssp_spi_dma_done(void *arg)
+{
+	struct callback_param *cb_param = (struct callback_param *)arg;
+	struct ssp_driver_context *drv_context = cb_param->drv_context;
+	struct device *dev = &drv_context->pdev->dev;
+	void *reg = drv_context->ioaddr;
+
+	if (cb_param->direction == TX_DIRECTION)
+		drv_context->txdma_done = 1;
+	else
+		drv_context->rxdma_done = 1;
+
+	dev_dbg(dev, "DMA callback for direction %d [RX done:%d] [TX done:%d]\n",
+		cb_param->direction, drv_context->rxdma_done,
+		drv_context->txdma_done);
+
+	if (drv_context->txdma_done && drv_context->rxdma_done) {
+		/* Clear Status Register */
+		write_SSSR(drv_context->clear_sr, reg);
+		dev_dbg(dev, "DMA done\n");
+		/* Disable Triggers to DMA or to CPU*/
+		disable_triggers(drv_context);
+		unmap_dma_buffers(drv_context);
+
+		queue_work(drv_context->dma_wq, &drv_context->complete_work);
+	}
+}
+
+/**
+ * intel_mid_ssp_spi_dma_init() - Initialize DMA
+ * @drv_context:	Pointer to the private driver context
+ *
+ * This function is called at driver setup phase to allocate DMA
+ * ressources.
+ */
+static void intel_mid_ssp_spi_dma_init(struct ssp_driver_context *drv_context)
+{
+	struct intel_mid_dma_slave *rxs, *txs;
+	struct dma_slave_config *ds;
+	dma_cap_mask_t mask;
+	struct device *dev = &drv_context->pdev->dev;
+
+	/* Configure RX channel parameters */
+	rxs = &drv_context->dmas_rx;
+	ds = &rxs->dma_slave;
+
+	ds->direction = DMA_FROM_DEVICE;
+	rxs->hs_mode = LNW_DMA_HW_HS;
+	rxs->cfg_mode = LNW_DMA_PER_TO_MEM;
+	ds->dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	ds->src_addr_width = drv_context->n_bytes;
+
+	/* Use a DMA burst according to the FIFO thresholds */
+	if (drv_context->rx_fifo_threshold == 8) {
+		ds->src_maxburst = 8;
+		ds->dst_maxburst = 8;
+	} else if (drv_context->rx_fifo_threshold == 4) {
+		ds->src_maxburst = 4;
+		ds->dst_maxburst = 4;
+	} else {
+		ds->src_maxburst = 1;
+		ds->dst_maxburst = 1;
+	}
+
+	/* Configure TX channel parameters */
+	txs = &drv_context->dmas_tx;
+	ds = &txs->dma_slave;
+
+	ds->direction = DMA_TO_DEVICE;
+	txs->hs_mode = LNW_DMA_HW_HS;
+	txs->cfg_mode = LNW_DMA_MEM_TO_PER;
+	ds->src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	ds->dst_addr_width = drv_context->n_bytes;
+
+	/* Use a DMA burst according to the FIFO thresholds */
+	if (drv_context->rx_fifo_threshold == 8) {
+		ds->src_maxburst = 8;
+		ds->dst_maxburst = 8;
+	} else if (drv_context->rx_fifo_threshold == 4) {
+		ds->src_maxburst = 4;
+		ds->dst_maxburst = 4;
+	} else {
+		ds->src_maxburst = 1;
+		ds->dst_maxburst = 1;
+	}
+
+	/* Nothing more to do if already initialized */
+	if (drv_context->dma_initialized)
+		return;
+
+	/* Use DMAC1 */
+	drv_context->dmac1 = pci_get_device(PCI_VENDOR_ID_INTEL,
+						PCI_MDFL_DMAC1_ID, NULL);
+
+	if (!drv_context->dmac1) {
+		dev_err(dev, "Can't find DMAC1");
+		return;
+	}
+
+	/* 1. Allocate rx channel */
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_MEMCPY, mask);
+	dma_cap_set(DMA_SLAVE, mask);
+
+	drv_context->rxchan = dma_request_channel(mask, chan_filter,
+		drv_context);
+	if (!drv_context->rxchan)
+		goto err_exit;
+
+	drv_context->rxchan->private = rxs;
+
+	/* 2. Allocate tx channel */
+	dma_cap_set(DMA_SLAVE, mask);
+	dma_cap_set(DMA_MEMCPY, mask);
+
+	drv_context->txchan = dma_request_channel(mask, chan_filter,
+		drv_context);
+
+	if (!drv_context->txchan)
+		goto free_rxchan;
+	else
+		drv_context->txchan->private = txs;
+
+	/* set the dma done bit to 1 */
+	drv_context->txdma_done = 1;
+	drv_context->rxdma_done = 1;
+
+	drv_context->tx_param.drv_context  = drv_context;
+	drv_context->tx_param.direction = TX_DIRECTION;
+	drv_context->rx_param.drv_context  = drv_context;
+	drv_context->rx_param.direction = RX_DIRECTION;
+
+	drv_context->dma_initialized = 1;
+
+	return;
+
+free_rxchan:
+	dma_release_channel(drv_context->rxchan);
+err_exit:
+	dev_err(dev, "Error : DMA Channel Not available\n");
+
+	pci_dev_put(drv_context->dmac1);
+	return;
+}
+
+/**
+ * intel_mid_ssp_spi_dma_exit() - Release DMA ressources
+ * @drv_context:	Pointer to the private driver context
+ */
+static void intel_mid_ssp_spi_dma_exit(struct ssp_driver_context *drv_context)
+{
+	dma_release_channel(drv_context->txchan);
+	dma_release_channel(drv_context->rxchan);
+	pci_dev_put(drv_context->dmac1);
+}
+
+/**
+ * dma_transfer() - Initiate a DMA transfer
+ * @drv_context:	Pointer to the private driver context
+ */
+static void dma_transfer(struct ssp_driver_context *drv_context)
+{
+	dma_addr_t ssdr_addr;
+	struct dma_async_tx_descriptor *txdesc = NULL, *rxdesc = NULL;
+	struct dma_chan *txchan, *rxchan;
+	enum dma_ctrl_flags flag;
+	struct device *dev = &drv_context->pdev->dev;
+
+	/* get Data Read/Write address */
+	ssdr_addr = (dma_addr_t)(drv_context->paddr + 0x10);
+
+	if (drv_context->tx_dma)
+		drv_context->txdma_done = 0;
+
+	if (drv_context->rx_dma)
+		drv_context->rxdma_done = 0;
+
+	/* 2. prepare the RX dma transfer */
+	txchan = drv_context->txchan;
+	rxchan = drv_context->rxchan;
+
+	flag = DMA_PREP_INTERRUPT | DMA_CTRL_ACK;
+
+	if (likely(drv_context->quirks & QUIRKS_DMA_USE_NO_TRAIL)) {
+		/* Since the DMA is configured to do 32bits access */
+		/* to/from the DDR, the DMA transfer size must be  */
+		/* a multiple of 4 bytes                           */
+		drv_context->len_dma_rx = drv_context->len & ~(4 - 1);
+		drv_context->len_dma_tx = drv_context->len_dma_rx;
+
+		/* In Rx direction, TRAIL Bytes are handled by memcpy */
+		if (drv_context->rx_dma &&
+			(drv_context->len_dma_rx >
+			drv_context->rx_fifo_threshold * drv_context->n_bytes))
+			drv_context->len_dma_rx =
+					TRUNCATE(drv_context->len_dma_rx,
+					drv_context->rx_fifo_threshold *
+					drv_context->n_bytes);
+		else if (!drv_context->rx_dma)
+			dev_err(dev, "ERROR : rx_dma is null\r\n");
+	} else {
+		/* TRAIL Bytes are handled by DMA */
+		if (drv_context->rx_dma) {
+			drv_context->len_dma_rx = drv_context->len;
+			drv_context->len_dma_tx = drv_context->len;
+		} else {
+			dev_err(dev, "ERROR : drv_context->rx_dma is null!\n");
+		}
+	}
+
+	rxdesc = rxchan->device->device_prep_dma_memcpy
+		(rxchan,				/* DMA Channel */
+		drv_context->rx_dma,			/* DAR */
+		ssdr_addr,				/* SAR */
+		drv_context->len_dma_rx,		/* Data Length */
+		flag);					/* Flag */
+
+	if (rxdesc) {
+		rxdesc->callback = intel_mid_ssp_spi_dma_done;
+		rxdesc->callback_param = &drv_context->rx_param;
+	} else {
+		dev_dbg(dev, "rxdesc is null! (len_dma_rx:%d)\n",
+			drv_context->len_dma_rx);
+		drv_context->rxdma_done = 1;
+	}
+
+	/* 3. prepare the TX dma transfer */
+	if (drv_context->tx_dma) {
+		txdesc = txchan->device->device_prep_dma_memcpy
+		(txchan,				/* DMA Channel */
+		ssdr_addr,				/* DAR */
+		drv_context->tx_dma,			/* SAR */
+		drv_context->len_dma_tx,		/* Data Length */
+		flag);					/* Flag */
+		if (txdesc) {
+			txdesc->callback = intel_mid_ssp_spi_dma_done;
+			txdesc->callback_param = &drv_context->tx_param;
+		} else {
+			dev_dbg(dev, "txdesc is null! (len_dma_tx:%d)\n",
+				drv_context->len_dma_tx);
+			drv_context->txdma_done = 1;
+		}
+	} else {
+		dev_err(dev, "ERROR : drv_context->tx_dma is null!\n");
+		return;
+	}
+
+	dev_info(dev, "DMA transfer len:%d len_dma_tx:%d len_dma_rx:%d\n",
+		drv_context->len, drv_context->len_dma_tx,
+		drv_context->len_dma_rx);
+
+	if (rxdesc || txdesc) {
+		if (rxdesc) {
+			dev_dbg(dev, "Firing DMA RX channel\n");
+			rxdesc->tx_submit(rxdesc);
+		}
+		if (txdesc) {
+			dev_dbg(dev, "Firing DMA TX channel\n");
+			txdesc->tx_submit(txdesc);
+		}
+	} else {
+		struct callback_param cb_param;
+		cb_param.drv_context = drv_context;
+		dev_dbg(dev, "Bypassing DMA transfer\n");
+		intel_mid_ssp_spi_dma_done(&cb_param);
+	}
+}
+
+/**
+ * map_dma_buffers() - Map DMA buffer before a transfer
+ * @drv_context:	Pointer to the private drivzer context
+ */
+static int map_dma_buffers(struct ssp_driver_context *drv_context)
+{
+	struct device *dev = &drv_context->pdev->dev;
+
+	if (unlikely(drv_context->dma_mapped)) {
+		dev_err(dev, "ERROR : DMA buffers already mapped\n");
+		return 0;
+	}
+	if (unlikely(drv_context->dma_mapped))
+		return 1;
+
+	drv_context->tx_dma =
+		dma_map_single(dev, drv_context->tx, drv_context->len,
+			PCI_DMA_TODEVICE);
+	if (unlikely(dma_mapping_error(dev, drv_context->tx_dma))) {
+		dev_err(dev, "ERROR : tx dma mapping failed\n");
+		return 0;
+	}
+
+	drv_context->rx_dma =
+		dma_map_single(dev, drv_context->rx, drv_context->len,
+			PCI_DMA_FROMDEVICE);
+	if (unlikely(dma_mapping_error(dev, drv_context->rx_dma))) {
+		dma_unmap_single(dev, drv_context->tx_dma,
+			drv_context->len, DMA_TO_DEVICE);
+		dev_err(dev, "ERROR : rx dma mapping failed\n");
+		return 0;
+	}
+	return 1;
+}
+
+/**
+ * drain_trail() - Handle trailing bytes of a transfer
+ * @drv_context:	Pointer to the private driver context
+ *
+ * This function handles the trailing bytes of a transfer for the case
+ * they are not handled by the DMA.
+ */
+void drain_trail(struct ssp_driver_context *drv_context)
+{
+	struct device *dev = &drv_context->pdev->dev;
+	void *reg = drv_context->ioaddr;
+
+	if (drv_context->len != drv_context->len_dma_rx) {
+		dev_dbg(dev, "Handling trailing bytes. SSSR:%08x\n",
+			read_SSSR(reg));
+		drv_context->rx += drv_context->len_dma_rx;
+		drv_context->tx += drv_context->len_dma_tx;
+
+		while ((drv_context->tx != drv_context->tx_end) ||
+			(drv_context->rx != drv_context->rx_end)) {
+			drv_context->read(drv_context);
+			drv_context->write(drv_context);
+		}
+	}
+}
+
+static void int_transfer_complete(struct ssp_driver_context *drv_context)
+{
+	void *reg = drv_context->ioaddr;
+	struct spi_message *msg;
+	struct device *dev = &drv_context->pdev->dev;
+	unsigned long flags;
+
+	spin_lock_irqsave(&drv_context->queue_lock, flags);
+	msg = drv_context->cur_msg;
+	drv_context->cur_msg = NULL;
+	queue_work(drv_context->transfer_queue, &drv_context->transfer_work);
+	spin_unlock_irqrestore(&drv_context->queue_lock, flags);
+
+	if (likely(drv_context->quirks & QUIRKS_DMA_USE_NO_TRAIL))
+		drain_trail(drv_context);
+	else
+		/* Stop getting Time Outs */
+		write_SSTO(0, reg);
+
+	msg->status = 0;
+	msg->actual_length = drv_context->len;
+
+#ifdef DUMP_RX
+	dump_trailer(dev, drv_context->rx, drv_context->len, 16);
+#endif
+
+	dev_dbg(dev, "End of transfer. SSSR:%08X\n", read_SSSR(reg));
+	if (likely(msg->complete))
+		msg->complete(msg->context);
+
+	pm_runtime_put(dev);
+}
+
+static void int_transfer_complete_work(struct work_struct *work)
+{
+	struct ssp_driver_context *drv_context = container_of(work,
+				struct ssp_driver_context, complete_work);
+
+	int_transfer_complete(drv_context);
+}
+
+static void poll_transfer_complete(struct ssp_driver_context *drv_context)
+{
+	struct spi_message *msg;
+	unsigned long flags;
+	struct device *dev = &drv_context->pdev->dev;
+
+	/* Update total byte transfered return count actual bytes read */
+	drv_context->cur_msg->actual_length +=
+		drv_context->len - (drv_context->rx_end - drv_context->rx);
+
+	drv_context->cur_msg->status = 0;
+
+	msg = drv_context->cur_msg;
+	if (likely(msg->complete))
+		msg->complete(msg->context);
+
+	spin_lock_irqsave(&drv_context->queue_lock, flags);
+	drv_context->cur_msg = NULL;
+	queue_work(drv_context->transfer_queue, &drv_context->transfer_work);
+	spin_unlock_irqrestore(&drv_context->queue_lock, flags);
+
+	pm_runtime_put(dev);
+}
+
+/**
+ * ssp_int() - Interrupt handler
+ * @irq
+ * @dev_id
+ *
+ * The SSP interrupt is not used for transfer which are handled by
+ * DMA or polling: only under/over run are catched to detect
+ * broken transfers.
+ */
+static irqreturn_t ssp_int(int irq, void *dev_id)
+{
+	struct ssp_driver_context *drv_context = dev_id;
+	void *reg = drv_context->ioaddr;
+	struct device *dev = &drv_context->pdev->dev;
+	u32 status = read_SSSR(reg);
+
+	/* It should never be our interrupt since SSP will */
+	/* only trigs interrupt for under/over run.        */
+	if (likely(!(status & drv_context->mask_sr)))
+		return IRQ_NONE;
+
+	if (status & SSSR_ROR || status & SSSR_TUR) {
+		dev_err(dev, "--- SPI ROR or TUR occurred : SSSR=%x\n",	status);
+		WARN_ON(1);
+		if (status & SSSR_ROR)
+			dev_err(dev, "we have Overrun\n");
+		if (status & SSSR_TUR)
+			dev_err(dev, "we have Underrun\n");
+	}
+
+	/* We can fall here when not using DMA mode */
+	if (!drv_context->cur_msg) {
+		disable_interface(drv_context);
+		disable_triggers(drv_context);
+	}
+	/* clear status register */
+	write_SSSR(drv_context->clear_sr, reg);
+	return IRQ_HANDLED;
+}
+
+static void poll_transfer(unsigned long data)
+{
+	struct ssp_driver_context *drv_context =
+		(struct ssp_driver_context *)data;
+
+	if (drv_context->tx)
+		while (drv_context->tx != drv_context->tx_end) {
+			drv_context->write(drv_context);
+			drv_context->read(drv_context);
+		}
+
+	while (!drv_context->read(drv_context))
+		cpu_relax();
+
+	poll_transfer_complete(drv_context);
+}
+
+static unsigned int ssp_get_clk_div(int speed)
+{
+	return max(100000000 / speed, 4) - 1;
+}
+
+static struct spi_message *get_message(struct ssp_driver_context *drv)
+{
+	struct spi_message *msg = NULL;
+	unsigned long flags;
+
+	spin_lock_irqsave(&drv->queue_lock, flags);
+
+	if (!list_empty(&drv->queue)) {
+		msg = list_entry(drv->queue.next, struct spi_message, queue);
+		list_del_init(&msg->queue);
+	}
+
+	spin_unlock_irqrestore(&drv->queue_lock, flags);
+
+	return msg;
+}
+
+/**
+ * transfer_messages() - workqueue function which processes spi message queue
+ */
+static void transfer_messages(struct work_struct *work)
+{
+	struct ssp_driver_context *drv_context =
+		container_of(work, struct ssp_driver_context, transfer_work);
+	struct chip_data *chip = NULL;
+	struct spi_transfer *transfer = NULL;
+	void *reg = drv_context->ioaddr;
+	u32 cr1;
+	struct device *dev = &drv_context->pdev->dev;
+	struct spi_message *msg;
+
+	pm_runtime_get_sync(dev);
+
+next_transfer:
+	if (drv_context->running == false) {
+		pm_runtime_put(dev);
+		return;
+	}
+
+	msg = drv_context->cur_msg = get_message(drv_context);
+	if (msg == NULL) {
+		pm_runtime_put(dev);
+		return;
+	}
+	chip = spi_get_ctldata(msg->spi);
+
+	/*
+	 * We handle only one transfer message since the protocol
+	 * module has to control the out of band signaling.
+	 */
+	transfer = list_entry(msg->transfers.next,
+				struct spi_transfer,
+				transfer_list);
+
+	/* Check transfer length */
+	if (unlikely((transfer->len > MAX_SPI_TRANSFER_SIZE) ||
+		(transfer->len == 0))) {
+		dev_warn(dev, "transfer length null or greater than %d\n",
+					MAX_SPI_TRANSFER_SIZE);
+		dev_warn(dev, "length = %d\n", transfer->len);
+		msg->status = -EINVAL;
+
+		if (msg->complete)
+			msg->complete(msg->context);
+
+		goto next_transfer;
+		return;
+	}
+
+	/* Flush any remaining data (in case of failed previous transfer) */
+	flush(drv_context);
+
+	drv_context->tx  = (void *)transfer->tx_buf;
+	drv_context->rx  = (void *)transfer->rx_buf;
+	drv_context->len = transfer->len;
+	drv_context->write = chip->write;
+	drv_context->read = chip->read;
+
+	if (likely(chip->dma_enabled)) {
+		drv_context->dma_mapped = map_dma_buffers(drv_context);
+		if (unlikely(!drv_context->dma_mapped))
+			goto next_transfer;
+	} else {
+		drv_context->write = drv_context->tx ?
+			chip->write : null_writer;
+		drv_context->read  = drv_context->rx ?
+			chip->read : null_reader;
+	}
+	drv_context->tx_end = drv_context->tx + transfer->len;
+	drv_context->rx_end = drv_context->rx + transfer->len;
+
+	/* Clear status  */
+	write_SSSR(drv_context->clear_sr, reg);
+
+	/* setup the CR1 control register */
+	cr1 = chip->cr1 | drv_context->cr1_sig;
+
+	if (likely(drv_context->quirks & QUIRKS_DMA_USE_NO_TRAIL)) {
+		/*
+		 * in case of len smaller than burst size, adjust the
+		 * RX threshold. All other cases will use the default
+		 * threshold value. The RX fifo threshold must be
+		 * aligned with the DMA RX transfer size, which may be
+		 * limited to a multiple of 4 bytes due to 32bits DDR
+		 * access.
+		 */
+		if  (drv_context->len / drv_context->n_bytes <=
+			drv_context->rx_fifo_threshold) {
+			u32 rx_fifo_threshold;
+
+			rx_fifo_threshold = (drv_context->len & ~(4 - 1)) /
+						drv_context->n_bytes;
+			cr1 &= ~(SSCR1_RFT);
+			cr1 |= SSCR1_RxTresh(rx_fifo_threshold)
+					& SSCR1_RFT;
+		} else {
+			write_SSTO(chip->timeout, reg);
+		}
+	}
+
+	dev_dbg(dev, "transfer len:%d  n_bytes:%d  cr0:%x  cr1:%x",
+			drv_context->len, drv_context->n_bytes, chip->cr0, cr1);
+
+	/* first set CR1 */
+	write_SSCR1(cr1, reg);
+
+	/* (re)start the SSP */
+	write_SSCR0(chip->cr0, reg);
+
+	if (likely(chip->dma_enabled)) {
+		dma_transfer(drv_context);
+	} else {
+		tasklet_schedule(&drv_context->poll_transfer);
+	}
+
+	return;
+}
+
+static int transfer(struct spi_device *spi, struct spi_message *msg)
+{
+	struct ssp_driver_context *drv_context =
+				spi_master_get_devdata(spi->master);
+	unsigned long flags;
+
+	spin_lock_irqsave(&drv_context->queue_lock, flags);
+
+	msg->actual_length = 0;
+	msg->status = -EINPROGRESS;
+
+	list_add_tail(&msg->queue, &drv_context->queue);
+	if (drv_context->running)
+		queue_work(drv_context->transfer_queue,
+				&drv_context->transfer_work);
+
+	spin_unlock_irqrestore(&drv_context->queue_lock, flags);
+	return 0;
+}
+
+/**
+ * setup() - Driver setup procedure
+ * @spi:	Pointeur to the spi_device struct
+ */
+static int setup(struct spi_device *spi)
+{
+	struct intel_mid_ssp_spi_chip *chip_info = NULL;
+	struct chip_data *chip;
+	struct ssp_driver_context *drv_context =
+		spi_master_get_devdata(spi->master);
+	u32 tx_fifo_threshold;
+	u32 burst_size;
+	u32 clk_div;
+
+	if (!spi->bits_per_word)
+		spi->bits_per_word = DFLT_BITS_PER_WORD;
+
+	if ((spi->bits_per_word < MIN_BITS_PER_WORD
+		|| spi->bits_per_word > MAX_BITS_PER_WORD))
+		return -EINVAL;
+
+	chip = spi_get_ctldata(spi);
+	if (!chip) {
+		chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
+		if (!chip) {
+			dev_err(&spi->dev,
+			"failed setup: can't allocate chip data\n");
+			return -ENOMEM;
+		}
+	}
+	chip->cr0 = SSCR0_Motorola | SSCR0_DataSize(spi->bits_per_word > 16 ?
+		spi->bits_per_word - 16 : spi->bits_per_word)
+			| SSCR0_SSE
+			| (spi->bits_per_word > 16 ? SSCR0_EDSS : 0);
+
+	/* protocol drivers may change the chip settings, so...  */
+	/* if chip_info exists, use it                           */
+	chip_info = spi->controller_data;
+
+	/* chip_info isn't always needed */
+	chip->cr1 = 0;
+	if (chip_info) {
+		burst_size = chip_info->burst_size;
+		if (burst_size > IMSS_FIFO_BURST_8)
+			burst_size = DFLT_FIFO_BURST_SIZE;
+
+		chip->timeout = chip_info->timeout;
+
+		if (chip_info->enable_loopback)
+			chip->cr1 |= SSCR1_LBM;
+
+		chip->dma_enabled = chip_info->dma_enabled;
+
+	} else {
+		/* if no chip_info provided by protocol driver, */
+		/* set default values                           */
+		dev_info(&spi->dev, "setting default chip values\n");
+
+		burst_size = DFLT_FIFO_BURST_SIZE;
+
+		chip->dma_enabled = 1;
+		if (drv_context->quirks & QUIRKS_DMA_USE_NO_TRAIL)
+			chip->timeout = 0;
+		else
+			chip->timeout = DFLT_TIMEOUT_VAL;
+	}
+	/* Set FIFO thresholds according to burst_size */
+	if (burst_size == IMSS_FIFO_BURST_8)
+		drv_context->rx_fifo_threshold = 8;
+	else if (burst_size == IMSS_FIFO_BURST_4)
+		drv_context->rx_fifo_threshold = 4;
+	else
+		drv_context->rx_fifo_threshold = 1;
+	tx_fifo_threshold = SPI_FIFO_SIZE - drv_context->rx_fifo_threshold;
+	chip->cr1 |= (SSCR1_RxTresh(drv_context->rx_fifo_threshold) &
+		SSCR1_RFT) | (SSCR1_TxTresh(tx_fifo_threshold) &
+		SSCR1_TFT);
+
+	drv_context->dma_mapped = 0;
+
+	/* setting phase and polarity. spi->mode comes from boardinfo */
+	if ((spi->mode & SPI_CPHA) != 0)
+		chip->cr1 |= SSCR1_SPH;
+	if ((spi->mode & SPI_CPOL) != 0)
+		chip->cr1 |= SSCR1_SPO;
+
+	if (drv_context->quirks & QUIRKS_SPI_SLAVE_CLOCK_MODE)
+		/* set slave mode */
+		chip->cr1 |= SSCR1_SCLKDIR | SSCR1_SFRMDIR;
+	chip->cr1 |= SSCR1_SCFR;        /* clock is not free running */
+
+	dev_dbg(&spi->dev, "%d bits/word, mode %d\n",
+		spi->bits_per_word,
+		spi->mode & 0x3);
+	if (spi->bits_per_word <= 8) {
+		chip->n_bytes = 1;
+		chip->read = u8_reader;
+		chip->write = u8_writer;
+	} else if (spi->bits_per_word <= 16) {
+		chip->n_bytes = 2;
+		chip->read = u16_reader;
+		chip->write = u16_writer;
+	} else if (spi->bits_per_word <= 32) {
+		chip->cr0 |= SSCR0_EDSS;
+		chip->n_bytes = 4;
+		chip->read = u32_reader;
+		chip->write = u32_writer;
+	} else {
+		dev_err(&spi->dev, "invalid wordsize\n");
+		return -EINVAL;
+	}
+
+	if ((drv_context->quirks & QUIRKS_SPI_SLAVE_CLOCK_MODE) == 0) {
+		chip->speed_hz = spi->max_speed_hz;
+		clk_div = ssp_get_clk_div(chip->speed_hz);
+		chip->cr0 |= clk_div << 8;
+	}
+	chip->bits_per_word = spi->bits_per_word;
+
+	spi_set_ctldata(spi, chip);
+
+	/* setup of drv_context members that will not change across transfers */
+	drv_context->n_bytes = chip->n_bytes;
+
+	if (chip->dma_enabled) {
+		intel_mid_ssp_spi_dma_init(drv_context);
+		drv_context->cr1_sig  = SSCR1_TSRE | SSCR1_RSRE;
+		drv_context->mask_sr  = SSSR_ROR | SSSR_TUR;
+		if (drv_context->quirks & QUIRKS_DMA_USE_NO_TRAIL)
+			drv_context->cr1_sig  |= SSCR1_TRAIL;
+	} else {
+		drv_context->cr1_sig = SSCR1_RIE | SSCR1_TIE | SSCR1_TINTE;
+		drv_context->mask_sr = SSSR_RFS | SSSR_TFS |
+				 SSSR_ROR | SSSR_TUR | SSSR_TINT;
+	}
+	drv_context->clear_sr = SSSR_TUR  | SSSR_ROR | SSSR_TINT;
+
+	return 0;
+}
+
+/**
+ * cleanup() - Driver cleanup procedure
+ * @spi:	Pointer to the spi_device struct
+ */
+static void cleanup(struct spi_device *spi)
+{
+	struct chip_data *chip = spi_get_ctldata(spi);
+	struct ssp_driver_context *drv_context =
+		spi_master_get_devdata(spi->master);
+
+	if (drv_context->dma_initialized)
+		intel_mid_ssp_spi_dma_exit(drv_context);
+
+	kfree(chip);
+	spi_set_ctldata(spi, NULL);
+}
+
+static int start_queue(struct ssp_driver_context *drv)
+{
+	unsigned long flags;
+	int status = 0;
+
+	spin_lock_irqsave(&drv->queue_lock, flags);
+
+	if (drv->running) {
+		spin_unlock_irqrestore(&drv->queue_lock, flags);
+		return -EBUSY;
+	}
+	drv->running = true;
+
+	spin_unlock_irqrestore(&drv->queue_lock, flags);
+
+	queue_work(drv->transfer_queue, &drv->transfer_work);
+
+	return status;
+}
+
+static int stop_queue(struct ssp_driver_context *drv)
+{
+	unsigned long flags;
+	int status = 0;
+
+	spin_lock_irqsave(&drv->queue_lock, flags);
+	if (!list_empty(&drv->queue))
+		return -EBUSY;
+
+	drv->running = false;
+
+	spin_unlock_irqrestore(&drv->queue_lock, flags);
+
+	return status;
+}
+
+static int destroy_queue(struct ssp_driver_context *drv)
+{
+	int status;
+
+	status = stop_queue(drv);
+	if (status != 0)
+		return status;
+
+	destroy_workqueue(drv->transfer_queue);
+	return 0;
+}
+
+/**
+ * intel_mid_ssp_spi_probe() - Driver probe procedure
+ * @pdev:	Pointer to the pci_dev struct
+ * @ent:	Pointer to the pci_device_id struct
+ */
+static int intel_mid_ssp_spi_probe(struct pci_dev *pdev,
+	const struct pci_device_id *ent)
+{
+	struct device *dev = &pdev->dev;
+	struct spi_master *master;
+	struct ssp_driver_context *drv_context = 0;
+	int status;
+	u32 iolen = 0;
+	u8 ssp_cfg;
+	int pos;
+	void __iomem *syscfg_ioaddr;
+	unsigned long syscfg;
+
+	/* Check if the SSP we are probed for has been allocated */
+	/* to operate as SPI. This information is retreived from */
+	/* the field adid of the Vendor-Specific PCI capability  */
+	/* which is used as a configuration register.            */
+	pos = pci_find_capability(pdev, PCI_CAP_ID_VNDR);
+	if (pos > 0) {
+		pci_read_config_byte(pdev,
+			pos + VNDR_CAPABILITY_ADID_OFFSET,
+			&ssp_cfg);
+	} else {
+		dev_info(dev, "No Vendor Specific PCI capability\n");
+		goto err_abort_probe;
+	}
+	if (SSP_CFG_GET_MODE(ssp_cfg) != SSP_CFG_SPI_MODE_ID) {
+		dev_info(dev, "Unsupported SSP mode (%02xh)\n",
+			ssp_cfg);
+		goto err_abort_probe;
+	}
+
+	dev_info(dev, "found PCI SSP controller"
+		" (ID: %04xh:%04xh cfg: %02xh)\n",
+		pdev->vendor, pdev->device, ssp_cfg);
+
+	status = pci_enable_device(pdev);
+	if (status)
+		return status;
+
+	/* Allocate Slave with space for drv_context and null dma buffer */
+	master = spi_alloc_master(dev, sizeof(struct ssp_driver_context));
+
+	if (!master) {
+		dev_err(dev, "cannot alloc spi_slave\n");
+		status = -ENOMEM;
+		goto err_free_0;
+	}
+
+	drv_context = spi_master_get_devdata(master);
+	drv_context->master = master;
+
+	drv_context->pdev = pdev;
+	drv_context->quirks = ent->driver_data;
+
+	/* Set platform & configuration quirks */
+	drv_context->quirks |= QUIRKS_DMA_USE_NO_TRAIL;
+	if (SSP_CFG_IS_SPI_SLAVE(ssp_cfg))
+		drv_context->quirks |= QUIRKS_SPI_SLAVE_CLOCK_MODE;
+
+	master->mode_bits = SPI_CPOL | SPI_CPHA;
+	master->bus_num = SSP_CFG_GET_SPI_BUS_NB(ssp_cfg);
+	master->num_chipselect = 1;
+	master->cleanup = cleanup;
+	master->setup = setup;
+	master->transfer = transfer;
+	drv_context->dma_wq = create_workqueue("intel_mid_ssp_spi");
+	INIT_WORK(&drv_context->complete_work, int_transfer_complete_work);
+
+	drv_context->dma_initialized = 0;
+
+	/* get basic io resource and map it */
+	drv_context->paddr = pci_resource_start(pdev, 0);
+	iolen = pci_resource_len(pdev, 0);
+
+	status = pci_request_region(pdev, 0, dev_name(&pdev->dev));
+	if (status)
+		goto err_free_1;
+
+	drv_context->ioaddr =
+		ioremap_nocache(drv_context->paddr, iolen);
+	if (!drv_context->ioaddr) {
+		status = -ENOMEM;
+		goto err_free_2;
+	}
+	dev_dbg(dev, "paddr = : %08lx", drv_context->paddr);
+	dev_dbg(dev, "ioaddr = : %p\n", drv_context->ioaddr);
+	dev_dbg(dev, "attaching to IRQ: %04x\n", pdev->irq);
+	dev_dbg(dev, "quirks = : %08lx\n", drv_context->quirks);
+
+	/* Attach to IRQ */
+	drv_context->irq = pdev->irq;
+	status = request_irq(drv_context->irq, ssp_int, IRQF_SHARED,
+		"intel_mid_ssp_spi", drv_context);
+	if (status < 0) {
+		dev_err(&pdev->dev, "can not get IRQ\n");
+		goto err_free_2;
+	}
+
+	if (drv_context->quirks & QUIRKS_PLATFORM_MDFL) {
+		/* get base address of DMA selector. */
+		syscfg = drv_context->paddr - SYSCFG;
+		syscfg_ioaddr = ioremap_nocache(syscfg, 0x10);
+		if (!syscfg_ioaddr) {
+			status = -ENOMEM;
+			goto err_free_3;
+		}
+		iowrite32(ioread32(syscfg_ioaddr) | 2, syscfg_ioaddr);
+	}
+
+	tasklet_init(&drv_context->poll_transfer, poll_transfer,
+		(unsigned long)drv_context);
+
+	/* Register with the SPI framework */
+	dev_info(dev, "register with SPI framework (bus spi%d)\n",
+		master->bus_num);
+
+	status = spi_register_master(master);
+
+	if (status != 0) {
+		dev_err(dev, "problem registering spi\n");
+		goto err_free_3;
+	}
+
+	pci_set_drvdata(pdev, drv_context);
+
+	INIT_LIST_HEAD(&drv_context->queue);
+	spin_lock_init(&drv_context->queue_lock);
+	INIT_WORK(&drv_context->transfer_work, transfer_messages);
+	drv_context->transfer_queue =
+		create_workqueue(dev_name(master->dev.parent));
+	if (drv_context->transfer_queue == NULL)
+		goto err_free_3;
+
+	start_queue(drv_context);
+	pm_suspend_ignore_children(&pdev->dev, true);
+	pm_runtime_put_noidle(&pdev->dev);
+	pm_runtime_allow(&pdev->dev);
+
+	return status;
+
+err_free_3:
+	free_irq(drv_context->irq, drv_context);
+err_free_2:
+	pci_release_region(pdev, 0);
+err_free_1:
+	spi_master_put(master);
+err_free_0:
+	pci_disable_device(pdev);
+
+	return status;
+err_abort_probe:
+	dev_info(dev, "Abort probe for SSP %04xh:%04xh\n",
+		pdev->vendor, pdev->device);
+	return -ENODEV;
+}
+
+/**
+ * intel_mid_ssp_spi_remove() - driver remove procedure
+ * @pdev:	Pointer to the pci_dev struct
+ */
+static void __devexit intel_mid_ssp_spi_remove(struct pci_dev *pdev)
+{
+	struct ssp_driver_context *drv_context = pci_get_drvdata(pdev);
+
+	if (!drv_context)
+		return;
+
+	pm_runtime_forbid(&pdev->dev);
+	pm_runtime_get_noresume(&pdev->dev);
+
+	/* Release IRQ */
+	free_irq(drv_context->irq, drv_context);
+
+	iounmap(drv_context->ioaddr);
+
+	destroy_queue(drv_context);
+
+	/* disconnect from the SPI framework */
+	spi_unregister_master(drv_context->master);
+
+	pci_set_drvdata(pdev, NULL);
+	pci_release_region(pdev, 0);
+	pci_disable_device(pdev);
+
+	return;
+}
+
+#ifdef CONFIG_PM
+/**
+ * intel_mid_ssp_spi_suspend() - Driver suspend procedure
+ * @pdev:	Pointer to the pci_dev struct
+ * @state:	pm_message_t
+ */
+static int intel_mid_ssp_spi_suspend(struct pci_dev *pdev, pm_message_t state)
+{
+	struct ssp_driver_context *drv_context = pci_get_drvdata(pdev);
+	int status;
+
+	dev_dbg(&pdev->dev, "suspend\n");
+
+	flush_workqueue(drv_context->transfer_queue);
+
+	status = stop_queue(drv_context);
+	if (status)
+		return status;
+
+	tasklet_disable(&drv_context->poll_transfer);
+
+	return 0;
+}
+
+/**
+ * intel_mid_ssp_spi_resume() - Driver resume procedure
+ * @pdev:	Pointer to the pci_dev struct
+ */
+static int intel_mid_ssp_spi_resume(struct pci_dev *pdev)
+{
+	struct ssp_driver_context *drv_context = pci_get_drvdata(pdev);
+	int status;
+
+	dev_dbg(&pdev->dev, "resume\n");
+
+	status = start_queue(drv_context);
+	if (status)
+		return status;
+
+	tasklet_enable(&drv_context->poll_transfer);
+
+	return 0;
+}
+#else
+#define intel_mid_ssp_spi_suspend NULL
+#define intel_mid_ssp_spi_resume NULL
+#endif /* CONFIG_PM */
+
+static int intel_mid_ssp_spi_runtime_suspend(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct ssp_driver_context *drv_context = pci_get_drvdata(pdev);
+	int status;
+
+	flush_workqueue(drv_context->transfer_queue);
+
+	status = stop_queue(drv_context);
+	if (status)
+		return status;
+
+	tasklet_disable(&drv_context->poll_transfer);
+	return 0;
+}
+
+static int intel_mid_ssp_spi_runtime_resume(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct ssp_driver_context *drv_context = pci_get_drvdata(pdev);
+	int status;
+
+	status = start_queue(drv_context);
+	if (status)
+		return status;
+
+	tasklet_enable(&drv_context->poll_transfer);
+	return 0;
+}
+
+static int intel_mid_ssp_spi_runtime_idle(struct device *dev)
+{
+	int err;
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct ssp_driver_context *drv = pci_get_drvdata(pdev);
+
+	if (!list_empty(&drv->queue))
+		return -EBUSY;
+
+	err = pm_schedule_suspend(dev, 500);
+	if (err != 0)
+		return 0;
+
+	return -EBUSY;
+}
+
+static const struct dev_pm_ops intel_mid_ssp_spi_pm = {
+	.runtime_suspend = intel_mid_ssp_spi_runtime_suspend,
+	.runtime_resume = intel_mid_ssp_spi_runtime_resume,
+	.runtime_idle = intel_mid_ssp_spi_runtime_idle,
+};
+
+static const struct pci_device_id pci_ids[] __devinitdata = {
+	/* MDFL SSP0 */
+	{ PCI_VDEVICE(INTEL, 0x0832), QUIRKS_PLATFORM_MDFL},
+	/* MDFL SSP1 */
+	{ PCI_VDEVICE(INTEL, 0x0825), QUIRKS_PLATFORM_MDFL},
+	/* MDFL SSP3 */
+	{ PCI_VDEVICE(INTEL, 0x0816), QUIRKS_PLATFORM_MDFL},
+	{},
+};
+
+static struct pci_driver intel_mid_ssp_spi_driver = {
+	.name =		DRIVER_NAME,
+	.id_table =	pci_ids,
+	.probe =	intel_mid_ssp_spi_probe,
+	.remove =	__devexit_p(intel_mid_ssp_spi_remove),
+	.suspend =	intel_mid_ssp_spi_suspend,
+	.resume =	intel_mid_ssp_spi_resume,
+	.driver = {
+		.pm = &intel_mid_ssp_spi_pm,
+	},
+};
+
+static int __init intel_mid_ssp_spi_init(void)
+{
+	return pci_register_driver(&intel_mid_ssp_spi_driver);
+}
+
+late_initcall(intel_mid_ssp_spi_init);
+
+static void __exit intel_mid_ssp_spi_exit(void)
+{
+	pci_unregister_driver(&intel_mid_ssp_spi_driver);
+}
+
+module_exit(intel_mid_ssp_spi_exit);
+
diff --git a/drivers/spi/spi-intel-mid-ssp.h b/drivers/spi/spi-intel-mid-ssp.h
new file mode 100644
index 0000000..11fad57
--- /dev/null
+++ b/drivers/spi/spi-intel-mid-ssp.h
@@ -0,0 +1,308 @@
+/*
+ *  Copyright (C) Intel 2009
+ *  Ken Mills <ken.k.mills-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
+ *  Sylvain Centelles <sylvain.centelles-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  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 SPI_INTEL_MID_SSP_H_
+#define SPI_INTEL_MID_SSP_H_
+
+#define PCI_MRST_DMAC1_ID	0x0814
+#define PCI_MDFL_DMAC1_ID	0x0827
+
+#define SSP_NOT_SYNC 0x400000
+#define MAX_SPI_TRANSFER_SIZE 8192
+#define MAX_BITBANGING_LOOP   10000
+#define SPI_FIFO_SIZE 16
+
+/* PM QoS define */
+#define MIN_EXIT_LATENCY 20
+
+/* SSP assignement configuration from PCI config */
+#define SSP_CFG_GET_MODE(ssp_cfg)	((ssp_cfg) & 0x07)
+#define SSP_CFG_GET_SPI_BUS_NB(ssp_cfg)	(((ssp_cfg) >> 3) & 0x07)
+#define SSP_CFG_IS_SPI_SLAVE(ssp_cfg)	((ssp_cfg) & 0x40)
+#define SSP_CFG_SPI_MODE_ID		1
+/* adid field offset is 6 inside the vendor specific capability */
+#define VNDR_CAPABILITY_ADID_OFFSET	6
+
+/* Driver's quirk flags */
+/* This workarround bufferizes data in the audio fabric SDRAM from  */
+/* where the DMA transfers will operate. Should be enabled only for */
+/* SPI slave mode.                                                  */
+#define QUIRKS_DMA_USE_NO_TRAIL		2
+/* If set, the driver will use PM_QOS to reduce the latency         */
+/* introduced by the deeper C-states which may produce over/under   */
+/* run issues. Must be used in slave mode. In master mode, the      */
+/* latency is not critical, but setting this workarround  may       */
+/* improve the SPI throughput.                                      */
+#define QUIRKS_USE_PM_QOS		4
+/* This quirks is set on Medfield                                   */
+#define QUIRKS_PLATFORM_MDFL		16
+/* If set, SPI is in slave clock mode                               */
+#define QUIRKS_SPI_SLAVE_CLOCK_MODE	64
+
+/* Uncomment to get RX and TX short dumps after each transfer */
+/* #define DUMP_RX 1 */
+#define MAX_TRAILING_BYTE_RETRY 16
+#define MAX_TRAILING_BYTE_LOOP 100
+#define DELAY_TO_GET_A_WORD 3
+#define DFLT_TIMEOUT_VAL 500
+
+#define DEFINE_SSP_REG(reg, off) \
+static inline u32 read_##reg(void *p) { return __raw_readl(p + (off)); } \
+static inline void write_##reg(u32 v, void *p) { __raw_writel(v, p + (off)); }
+
+#define RX_DIRECTION 0
+#define TX_DIRECTION 1
+
+#define I2C_ACCESS_USDELAY 10
+
+#define DFLT_BITS_PER_WORD 16
+#define MIN_BITS_PER_WORD     4
+#define MAX_BITS_PER_WORD     32
+#define DFLT_FIFO_BURST_SIZE	IMSS_FIFO_BURST_8
+
+#define TRUNCATE(x, a) ((x) & ~((a)-1))
+
+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_SSP_REG(I2CCTRL, 0x00);
+DEFINE_SSP_REG(I2CDATA, 0x04);
+
+DEFINE_SSP_REG(GPLR1, 0x04);
+DEFINE_SSP_REG(GPDR1, 0x0c);
+DEFINE_SSP_REG(GPSR1, 0x14);
+DEFINE_SSP_REG(GPCR1, 0x1C);
+DEFINE_SSP_REG(GAFR1_U, 0x44);
+
+#define SYSCFG  0x20bc0
+
+#define SRAM_BASE_ADDR 0xfffdc000
+#define SRAM_RX_ADDR   SRAM_BASE_ADDR
+#define SRAM_TX_ADDR  (SRAM_BASE_ADDR + MAX_SPI_TRANSFER_SIZE)
+
+#define SSCR0_DSS   (0x0000000f)     /* Data Size Select (mask) */
+#define SSCR0_DataSize(x)  ((x) - 1)    /* Data Size Select [4..16] */
+#define SSCR0_FRF   (0x00000030)     /* FRame Format (mask) */
+#define SSCR0_Motorola        (0x0 << 4)         /* Motorola's SPI mode */
+#define SSCR0_ECS   (1 << 6) /* External clock select */
+#define SSCR0_SSE   (1 << 7) /* Synchronous Serial Port Enable */
+
+#define SSCR0_SCR   (0x000fff00)      /* Serial Clock Rate (mask) */
+#define SSCR0_SerClkDiv(x) (((x) - 1) << 8) /* Divisor [1..4096] */
+#define SSCR0_EDSS  (1 << 20)           /* Extended data size select */
+#define SSCR0_NCS   (1 << 21)           /* Network clock select */
+#define SSCR0_RIM    (1 << 22)           /* Receive FIFO overrrun int mask */
+#define SSCR0_TUM   (1 << 23)           /* Transmit FIFO underrun int mask */
+#define SSCR0_FRDC (0x07000000)     /* Frame rate divider control (mask) */
+#define SSCR0_SlotsPerFrm(x) (((x) - 1) << 24) /* Time slots per frame */
+#define SSCR0_ADC   (1 << 30)           /* Audio clock select */
+#define SSCR0_MOD  (1 << 31)           /* Mode (normal or network) */
+
+#define SSCR1_RIE    (1 << 0) /* Receive FIFO Interrupt Enable */
+#define SSCR1_TIE     (1 << 1) /* Transmit FIFO Interrupt Enable */
+#define SSCR1_LBM   (1 << 2) /* Loop-Back Mode */
+#define SSCR1_SPO   (1 << 3) /* SSPSCLK polarity setting */
+#define SSCR1_SPH   (1 << 4) /* Motorola SPI SSPSCLK phase setting */
+#define SSCR1_MWDS           (1 << 5) /* Microwire Transmit Data Size */
+#define SSCR1_TFT    (0x000003c0)     /* Transmit FIFO Threshold (mask) */
+#define SSCR1_TxTresh(x) (((x) - 1) << 6) /* level [1..16] */
+#define SSCR1_RFT    (0x00003c00)     /* Receive FIFO Threshold (mask) */
+#define SSCR1_RxTresh(x) (((x) - 1) << 10) /* level [1..16] */
+
+#define SSSR_TNF		(1 << 2)	/* Tx FIFO Not Full */
+#define SSSR_RNE		(1 << 3)	/* Rx FIFO Not Empty */
+#define SSSR_BSY		(1 << 4)	/* SSP Busy */
+#define SSSR_TFS		(1 << 5)	/* Tx FIFO Service Request */
+#define SSSR_RFS		(1 << 6)	/* Rx FIFO Service Request */
+#define SSSR_ROR		(1 << 7)	/* Rx FIFO Overrun */
+#define SSSR_TFL_MASK           (0x0F << 8)     /* Tx FIFO level field mask */
+
+#define SSCR0_TIM    (1 << 23)          /* Transmit FIFO Under Run Int Mask */
+#define SSCR0_RIM    (1 << 22)          /* Receive FIFO Over Run int Mask */
+#define SSCR0_NCS    (1 << 21)          /* Network Clock Select */
+#define SSCR0_EDSS   (1 << 20)          /* Extended Data Size Select */
+
+#define SSCR0_TISSP      (1 << 4)  /* TI Sync Serial Protocol */
+#define SSCR0_PSP        (3 << 4)  /* PSP - Programmable Serial Protocol */
+#define SSCR1_TTELP      (1 << 31) /* TXD Tristate Enable Last Phase */
+#define SSCR1_TTE        (1 << 30) /* TXD Tristate Enable */
+#define SSCR1_EBCEI      (1 << 29) /* Enable Bit Count Error interrupt */
+#define SSCR1_SCFR       (1 << 28) /* Slave Clock free Running */
+#define SSCR1_ECRA       (1 << 27) /* Enable Clock Request A */
+#define SSCR1_ECRB       (1 << 26) /* Enable Clock request B */
+#define SSCR1_SCLKDIR    (1 << 25) /* Serial Bit Rate Clock Direction */
+#define SSCR1_SFRMDIR    (1 << 24) /* Frame Direction */
+#define SSCR1_RWOT       (1 << 23) /* Receive Without Transmit */
+#define SSCR1_TRAIL      (1 << 22) /* Trailing Byte */
+#define SSCR1_TSRE       (1 << 21) /* Transmit Service Request Enable */
+#define SSCR1_RSRE       (1 << 20) /* Receive Service Request Enable */
+#define SSCR1_TINTE      (1 << 19) /* Receiver Time-out Interrupt enable */
+#define SSCR1_PINTE      (1 << 18) /* Trailing Byte Interupt Enable */
+#define SSCR1_STRF       (1 << 15) /* Select FIFO or EFWR */
+#define SSCR1_EFWR       (1 << 14) /* Enable FIFO Write/Read */
+#define SSCR1_IFS        (1 << 16) /* Invert Frame Signal */
+
+#define SSSR_BCE         (1 << 23) /* Bit Count Error */
+#define SSSR_CSS         (1 << 22) /* Clock Synchronisation Status */
+#define SSSR_TUR         (1 << 21) /* Transmit FIFO Under Run */
+#define SSSR_EOC         (1 << 20) /* End Of Chain */
+#define SSSR_TINT        (1 << 19) /* Receiver Time-out Interrupt */
+#define SSSR_PINT        (1 << 18) /* Peripheral Trailing Byte Interrupt */
+
+#define SSPSP_FSRT       (1 << 25)   /* Frame Sync Relative Timing */
+#define SSPSP_DMYSTOP(x) ((x) << 23) /* Dummy Stop */
+#define SSPSP_SFRMWDTH(x)((x) << 16) /* Serial Frame Width */
+#define SSPSP_SFRMDLY(x) ((x) << 9)  /* Serial Frame Delay */
+#define SSPSP_DMYSTRT(x) ((x) << 7)  /* Dummy Start */
+#define SSPSP_STRTDLY(x) ((x) << 4)  /* Start Delay */
+#define SSPSP_ETDS       (1 << 3)    /* End of Transfer data State */
+#define SSPSP_SFRMP      (1 << 2)    /* Serial Frame Polarity */
+#define SSPSP_SCMODE(x)  ((x) << 0)  /* Serial Bit Rate Clock Mode */
+
+/*
+ * For testing SSCR1 changes that require SSP restart, basically
+ * everything except 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)
+
+struct callback_param {
+	void *drv_context;
+	u32 direction;
+};
+
+struct ssp_driver_context {
+	/* Driver model hookup */
+	struct pci_dev *pdev;
+
+	/* SPI framework hookup */
+	struct spi_master *master;
+
+	/* SSP register addresses */
+	unsigned long paddr;
+	void *ioaddr;
+	int irq;
+
+	/* SSP masks*/
+	u32 cr1_sig;
+	u32 cr1;
+	u32 clear_sr;
+	u32 mask_sr;
+
+	struct tasklet_struct poll_transfer;
+
+	spinlock_t lock;
+
+	/* Current message transfer state info */
+	struct spi_message *cur_msg;
+	size_t len;
+	size_t len_dma_rx;
+	size_t len_dma_tx;
+	void *tx;
+	void *tx_end;
+	void *rx;
+	void *rx_end;
+	bool dma_initialized;
+	int dma_mapped;
+	dma_addr_t rx_dma;
+	dma_addr_t tx_dma;
+	u8 n_bytes;
+	int (*write)(struct ssp_driver_context *drv_context);
+	int (*read)(struct ssp_driver_context *drv_context);
+
+	struct intel_mid_dma_slave    dmas_tx;
+	struct intel_mid_dma_slave    dmas_rx;
+	struct dma_chan    *txchan;
+	struct dma_chan    *rxchan;
+	struct workqueue_struct *dma_wq;
+	struct work_struct complete_work;
+
+	spinlock_t 		queue_lock;
+	struct list_head	queue;
+	struct workqueue_struct	*transfer_queue;
+	struct work_struct	transfer_work;
+	bool			running;
+
+	int txdma_done;
+	int rxdma_done;
+	struct callback_param tx_param;
+	struct callback_param rx_param;
+	struct pci_dev *dmac1;
+
+	unsigned long quirks;
+	u32 rx_fifo_threshold;
+};
+
+struct chip_data {
+	u32 cr0;
+	u32 cr1;
+	u32 timeout;
+	u8 n_bytes;
+	u8 dma_enabled;
+	u8 bits_per_word;
+	u32 speed_hz;
+	int (*write)(struct ssp_driver_context *drv_context);
+	int (*read)(struct ssp_driver_context *drv_context);
+};
+
+
+enum intel_mid_ssp_spi_fifo_burst {
+	IMSS_FIFO_BURST_1,
+	IMSS_FIFO_BURST_4,
+	IMSS_FIFO_BURST_8
+};
+
+/* spi_board_info.controller_data for SPI slave devices,
+ * copied to spi_device.platform_data ... mostly for dma tuning
+ */
+struct intel_mid_ssp_spi_chip {
+	enum intel_mid_ssp_spi_fifo_burst burst_size;
+	u32 timeout;
+	u8 enable_loopback;
+	u8 dma_enabled;
+};
+
+
+#define SPI_DIB_NAME_LEN  16
+#define SPI_DIB_SPEC_INFO_LEN      10
+
+struct spi_dib_header {
+	u32       signature;
+	u32       length;
+	u8         rev;
+	u8         checksum;
+	u8         dib[0];
+} __attribute__((packed));
+
+#endif /* SPI_INTEL_MID_SSP_H_*/


------------------------------------------------------------------------------
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