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SubjectRe: [PATCH 1/1] spi: intel_mid_ssp_spi: new SPI driver for intel Medfield platform
On Wed, Feb 02, 2011 at 10:40:54PM +0000, Alan Cox wrote:
> On Wed, 2 Feb 2011 13:01:52 -0800
> Russ Gorby <russ.gorby@intel.com> wrote:
> > SPI master controller driver for the Intel MID platform Medfield
> > This driver uses the Penwell SSP controller and configures it to
> > be a SPI device (spibus 3). This bus supports a single device -
> > the 3G SPI modem that can operate up to 25Mhz.
>
> And this is the unified one that handles all the devices, but I gather
> may need some fixing/test work on Medfield.
>
> (and the only reason you haven't seen this submitted yet is I was
> asked to wait until it had been tested on those platforms. So I'm
> very surprised to see the other submission)
>
> Alan
>
> --
>
> From: Mathieu SOULARD <mathieux.soulard@intel.com>
>
> intel_mid_ssp_spi: Moorestown and Medfield SPI for SSP devices
>
> 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@intel.com>
> [Ported to the -next tree DMA engine]
> Signed-off-by: Alan Cox <alan@linux.intel.com>
>
> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> index bb233a9..6d1a41f 100644
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
> @@ -178,6 +178,14 @@ 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 86d1b5f..6e052b5 100644
> --- a/drivers/spi/Makefile
> +++ b/drivers/spi/Makefile
> @@ -24,6 +24,7 @@ obj-$(CONFIG_SPI_DW_MMIO) += dw_spi_mmio.o
> obj-$(CONFIG_SPI_EP93XX) += ep93xx_spi.o
> obj-$(CONFIG_SPI_GPIO) += spi_gpio.o
> obj-$(CONFIG_SPI_IMX) += spi_imx.o
> +obj-$(CONFIG_SPI_INTEL_MID_SSP) += intel_mid_ssp_spi.o

Please use "spi_" as a prefix instead of a "_spi" suffix on spi
drivers. I'm asking for all new spi drivers to follow this
convention.

> obj-$(CONFIG_SPI_LM70_LLP) += spi_lm70llp.o
> obj-$(CONFIG_SPI_PXA2XX) += pxa2xx_spi.o
> obj-$(CONFIG_SPI_PXA2XX_PCI) += pxa2xx_spi_pci.o
> diff --git a/drivers/spi/intel_mid_ssp_spi.c b/drivers/spi/intel_mid_ssp_spi.c
> new file mode 100644
> index 0000000..2d6d881
> --- /dev/null
> +++ b/drivers/spi/intel_mid_ssp_spi.c
> @@ -0,0 +1,1403 @@
> +/*
> + * intel_mid_ssp_spi.c

Nit: Personally, I prefer not to have the filename in the header
block.

> + * This driver supports Bulverde SSP core used on Intel MID platforms
> + * It supports SSP of Moorestown & Medfield platforms and handles clock
> + * slave & master modes.
> + *
> + * Copyright (c) 2010, Intel Corporation.
> + * Ken Mills <ken.k.mills@intel.com>
> + * Sylvain Centelles <sylvain.centelles@intel.com>
> + *
> + * 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/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_params.h>
> +
> +#include <linux/spi/spi.h>
> +#include "intel_mid_ssp_spi.h"

This file is only included once by this file. Everything in
intel_mid_ssp_spi.h should be moved into this file.

> +
> +#define DRIVER_NAME "intel_mid_ssp_spi_unified"

Used exactly once. Drop the #defile and move it inline.

> +
> +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)

All symbols should use the driver's prefix, including
non-exported statics and debug functions. Currently that is
"intel_mid_ssp_spi_" (which is a little long, it can probably
be abbreviated a bit).

> +{
> + int tlen1 = (len < sz ? len : sz);
> + int tlen2 = ((len - sz) > sz) ? sz : (len - sz);
> + unsigned char *p;
> + static char msg[MAX_SPI_TRANSFER_SIZE];

Wait, 8k on the stack!?! No, wait, this is a static, which is also a
very bad idea because it means there can never be concurrent accesses
to this function. Don't use a static buffer for this; instead send
the output to the console as you generate it. Get rid of all the
sprintf stuff.

> +
> + 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;

or more simply:

+ u32 sssr = read_SSSR(drv_context->ioaddr);
+ return ((sssr & SSSR_TFL_MASK) == 0 && (sssr & SSSR_TNF) != 0)

> +}
> +
> +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;

Drop the superfluous '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;

It's unusual in linux for a return value of '0' to be the failure
case. Some comments describing what is being tested for would also
make it easier to understand.

> +
> + 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;

The following is an accepted pattern for this:

write_SSDR(*(u8 *)(drv_context->tx++), reg);

> +
> + 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;

ditto

> + }
> +
> + 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;

This test is identical to the u8 version, and same in the u32 version
below. A macro would probably be appropriate.

> +
> + 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;

Ditto

> + }
> +
> + 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;
> + unsigned int device_id;
> +
> + /* 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;
> + }

Other than the ->direction and ->cfg_mode settings, these two blocks
are identical. Maybe this could be simplified? Also, the maxburst
values are the same for both dst_ and src_ on both halves. It can
probably be calculated once and used to initialize both dma
structures.

> +
> + /* Nothing more to do if already initialized */
> + if (drv_context->dma_initialized)
> + return;
> +
> + /* Use DMAC1 */
> + if (drv_context->quirks & QUIRKS_PLATFORM_MRST)
> + device_id = PCI_MRST_DMAC1_ID;
> + else
> + device_id = PCI_MDFL_DMAC1_ID;
> +
> + drv_context->dmac1 = pci_get_device(PCI_VENDOR_ID_INTEL,
> + device_id, NULL);
> +
> + if (!drv_context->dmac1) {
> + dev_err(dev, "Can't find DMAC1");
> + return;
> + }
> +
> + if (drv_context->quirks & QUIRKS_SRAM_ADDITIONAL_CPY) {
> + drv_context->virt_addr_sram_rx = ioremap_nocache(SRAM_BASE_ADDR,
> + 2 * MAX_SPI_TRANSFER_SIZE);
> + if (drv_context->virt_addr_sram_rx)
> + drv_context->virt_addr_sram_tx =
> + drv_context->virt_addr_sram_rx +
> + MAX_SPI_TRANSFER_SIZE;
> + else
> + dev_err(dev, "Virt_addr_sram_rx is null\n");
> + }
> +
> + /* 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");
> +
> + if (drv_context->quirks & QUIRKS_SRAM_ADDITIONAL_CPY)
> + iounmap(drv_context->virt_addr_sram_rx);
> +
> + 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);
> +
> + if (drv_context->quirks & QUIRKS_SRAM_ADDITIONAL_CPY)
> + iounmap(drv_context->virt_addr_sram_rx);
> +
> + 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 */

Keep leading '(' on the line with the function name please.

> + 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 */

Ditto, and indent the parameters. The comments at the end of the line
aren't at all helpful (they state obvious facts instead of talking
about what the driver is /doing/).

> + 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;
> + }

Revers the logic so that the else block comes first and then the if
block can lose an indentation level. Like this:

+ if (!drv_context->tx_dma) {
+ dev_err(dev, "ERROR : drv_context->tx_dma is null!\n");
+ return;
+ }
+ txdesc = txchan->device->device_prep_dma_memcpy(...);
+ ...
> +
> + 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);
> + }

Ditto here, the logic would read better if it was reversed so the else
block comes first.

> +}
> +
> +/**
> + * 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->quirks & QUIRKS_SRAM_ADDITIONAL_CPY)) {
> + /* Copy drv_context->tx into sram_tx */
> + memcpy_toio(drv_context->virt_addr_sram_tx, drv_context->tx,
> + drv_context->len);
> +#ifdef DUMP_RX
> + dump_trailer(&drv_context->pdev->dev, drv_context->tx,
> + drv_context->len, 16);
> +#endif
> + drv_context->rx_dma = SRAM_RX_ADDR;
> + drv_context->tx_dma = SRAM_TX_ADDR;
> + } else {
> + /* no QUIRKS_SRAM_ADDITIONAL_CPY */
> + 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);
> + }
> + }
> +}
> +
> +/**
> + * sram_to_ddr_cpy() - Copy data from Langwell SDRAM to DDR
> + * @drv_context: Pointer to the private driver context
> + */
> +static void sram_to_ddr_cpy(struct ssp_driver_context *drv_context)
> +{
> + u32 length = drv_context->len;
> +
> + if ((drv_context->quirks & QUIRKS_DMA_USE_NO_TRAIL)
> + && (drv_context->len > drv_context->rx_fifo_threshold *
> + drv_context->n_bytes))
> + length = TRUNCATE(drv_context->len,
> + drv_context->rx_fifo_threshold * drv_context->n_bytes);
> +
> + memcpy_fromio(drv_context->rx, drv_context->virt_addr_sram_rx, length);
> +}
> +
> +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;
> +
> + if (unlikely(drv_context->quirks & QUIRKS_USE_PM_QOS))
> + pm_qos_update_request(&drv_context->pm_qos_req,
> + PM_QOS_DEFAULT_VALUE);
> +
> + if (unlikely(drv_context->quirks & QUIRKS_SRAM_ADDITIONAL_CPY))
> + sram_to_ddr_cpy(drv_context);
> +
> + if (likely(drv_context->quirks & QUIRKS_DMA_USE_NO_TRAIL))
> + drain_trail(drv_context);
> + else
> + /* Stop getting Time Outs */
> + write_SSTO(0, reg);
> +
> + drv_context->cur_msg->status = 0;
> + drv_context->cur_msg->actual_length = drv_context->len;
> +
> +#ifdef DUMP_RX
> + dump_trailer(dev, drv_context->rx, drv_context->len, 16);
> +#endif

If you add a #else clause at the definition point of dump_trailer that
implements an empty version of the function, then the #ifdef/#endif
can be dropped here.

> +
> + dev_dbg(dev, "End of transfer. SSSR:%08X\n", read_SSSR(reg));
> + msg = drv_context->cur_msg;
> + if (likely(msg->complete))
> + msg->complete(msg->context);
> +}
> +
> +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;
> +
> + /* 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);
> +}
> +
> +/**
> + * 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);
> +}
> +
> +/**
> + * start_bitbanging() - Clock synchronization by bit banging
> + * @drv_context: Pointer to private driver context
> + *
> + * This clock synchronization will be removed as soon as it is
> + * handled by the SCU.
> + */
> +static void start_bitbanging(struct ssp_driver_context *drv_context)
> +{
> + u32 sssr;
> + u32 count = 0;
> + u32 cr0;
> + void *i2c_reg = drv_context->I2C_ioaddr;
> + struct device *dev = &drv_context->pdev->dev;
> + void *reg = drv_context->ioaddr;
> + struct chip_data *chip = spi_get_ctldata(drv_context->cur_msg->spi);
> + cr0 = chip->cr0;
> +
> + dev_warn(dev, "In %s : Starting bit banging\n",\
> + __func__);
> + if (read_SSSR(reg) & SSP_NOT_SYNC)
> + dev_warn(dev, "SSP clock desynchronized.\n");
> + if (!(read_SSCR0(reg) & SSCR0_SSE))
> + dev_warn(dev, "in SSCR0, SSP disabled.\n");
> +
> + dev_dbg(dev, "SSP not ready, start CLK sync\n");
> +
> + write_SSCR0(cr0 & ~SSCR0_SSE, reg);
> + write_SSPSP(0x02010007, reg);
> +
> + write_SSTO(chip->timeout, reg);
> + write_SSCR0(cr0, reg);
> +
> + /*
> + * This routine uses the DFx block to override the SSP inputs
> + * and outputs allowing us to bit bang SSPSCLK. On Langwell,
> + * we have to generate the clock to clear busy.
> + */
> + write_I2CDATA(0x3, i2c_reg);
> + udelay(I2C_ACCESS_USDELAY);
> + write_I2CCTRL(0x01070034, i2c_reg);
> + udelay(I2C_ACCESS_USDELAY);
> + write_I2CDATA(0x00000099, i2c_reg);
> + udelay(I2C_ACCESS_USDELAY);
> + write_I2CCTRL(0x01070038, i2c_reg);
> + udelay(I2C_ACCESS_USDELAY);
> + sssr = read_SSSR(reg);
> +
> + /* Bit bang the clock until CSS clears */
> + while ((sssr & 0x400000) && (count < MAX_BITBANGING_LOOP)) {
> + write_I2CDATA(0x2, i2c_reg);
> + udelay(I2C_ACCESS_USDELAY);
> + write_I2CCTRL(0x01070034, i2c_reg);
> + udelay(I2C_ACCESS_USDELAY);
> + write_I2CDATA(0x3, i2c_reg);
> + udelay(I2C_ACCESS_USDELAY);
> + write_I2CCTRL(0x01070034, i2c_reg);
> + udelay(I2C_ACCESS_USDELAY);
> + sssr = read_SSSR(reg);
> + count++;
> + }
> + if (count >= MAX_BITBANGING_LOOP)
> + dev_err(dev, "ERROR in %s : infinite loop \
> + on bit banging. Aborting\n", __func__);
> +
> + dev_dbg(dev, "---Bit bang count=%d\n", count);
> +
> + write_I2CDATA(0x0, i2c_reg);
> + udelay(I2C_ACCESS_USDELAY);
> + write_I2CCTRL(0x01070038, i2c_reg);
> +}
> +
> +static unsigned int ssp_get_clk_div(int speed)
> +{
> + return max(100000000 / speed, 4) - 1;
> +}
> +
> +/**
> + * transfer() - Start a SPI transfer
> + * @spi: Pointer to the spi_device struct
> + * @msg: Pointer to the spi_message struct
> + */
> +static int transfer(struct spi_device *spi, struct spi_message *msg)
> +{
> + struct ssp_driver_context *drv_context = \
> + spi_master_get_devdata(spi->master);
> + struct chip_data *chip = NULL;
> + struct spi_transfer *transfer = NULL;
> + void *reg = drv_context->ioaddr;
> + u32 cr1;
> + struct device *dev = &drv_context->pdev->dev;
> + chip = spi_get_ctldata(msg->spi);
> +
> + msg->actual_length = 0;
> + msg->status = -EINPROGRESS;
> + drv_context->cur_msg = msg;
> +
> + /* 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);
> +
> + return 0;
> + }
> +
> + /* 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;

tx_buf and rx_buf are already void* (well, tx_buf is const void *).
The casts should be unnecessary. drv_context->tx should probably be a
const too.

> + 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))
> + return 0;
> + } 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. */

Please use continuous comment blocks:

/*
* ...
* ...
*/
This goes for the whole patch.

> + 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);
> +
> + /* Do bitbanging only if SSP not-enabled or not-synchronized */
> + if (unlikely(((read_SSSR(reg) & SSP_NOT_SYNC) ||
> + (!(read_SSCR0(reg) & SSCR0_SSE))) &&
> + (drv_context->quirks & QUIRKS_BIT_BANGING))) {
> + start_bitbanging(drv_context);
> + } else {
> + /* (re)start the SSP */
> + write_SSCR0(chip->cr0, reg);
> + }
> +
> + if (likely(chip->dma_enabled)) {
> + if (unlikely(drv_context->quirks & QUIRKS_USE_PM_QOS))
> + pm_qos_update_request(&drv_context->pm_qos_req,
> + MIN_EXIT_LATENCY);
> + dma_transfer(drv_context);
> + } else {
> + tasklet_schedule(&drv_context->poll_transfer);
> + }
> +
> + 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);
> +
> + /* Remove the PM_QOS request */
> + if (drv_context->quirks & QUIRKS_USE_PM_QOS)
> + pm_qos_remove_request(&drv_context->pm_qos_req);
> +
> + kfree(chip);
> + spi_set_ctldata(spi, NULL);
> +}
> +
> +/**
> + * 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 */
> + if (drv_context->quirks & QUIRKS_PLATFORM_MRST) {
> + /* Apply bit banging workarround on MRST */
> + drv_context->quirks |= QUIRKS_BIT_BANGING;
> + /* MRST slave mode workarrounds */
> + if (SSP_CFG_IS_SPI_SLAVE(ssp_cfg))
> + drv_context->quirks |=
> + QUIRKS_USE_PM_QOS |
> + QUIRKS_SRAM_ADDITIONAL_CPY;
> + }
> + 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);
> +
> + if (drv_context->quirks & QUIRKS_BIT_BANGING) {
> + /* Bit banging on the clock is done through */
> + /* DFT which is available through I2C. */
> + /* get base address of I2C_Serbus registers */
> + drv_context->I2C_paddr = 0xff12b000;
> + drv_context->I2C_ioaddr =
> + ioremap_nocache(drv_context->I2C_paddr, 0x10);
> + if (!drv_context->I2C_ioaddr) {
> + status = -ENOMEM;
> + goto err_free_3;
> + }
> + }
> +
> + /* 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_4;
> + }
> +
> + 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_5;
> + }
> + 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_5;
> + }
> +
> + pci_set_drvdata(pdev, drv_context);
> +
> + /* Create the PM_QOS request */
> + if (drv_context->quirks & QUIRKS_USE_PM_QOS)
> + pm_qos_add_request(&drv_context->pm_qos_req,
> + PM_QOS_CPU_DMA_LATENCY,
> + PM_QOS_DEFAULT_VALUE);
> +
> + return status;
> +
> +err_free_5:
> + free_irq(drv_context->irq, drv_context);
> +err_free_4:
> + iounmap(drv_context->I2C_ioaddr);
> +err_free_3:
> + iounmap(drv_context->ioaddr);
> +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;
> +
> + /* Release IRQ */
> + free_irq(drv_context->irq, drv_context);
> +
> + iounmap(drv_context->ioaddr);
> + if (drv_context->quirks & QUIRKS_BIT_BANGING)
> + iounmap(drv_context->I2C_ioaddr);
> +
> + /* 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);
> + dev_dbg(&pdev->dev, "suspend\n");
> +
> + 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);
> + dev_dbg(&pdev->dev, "resume\n");
> +
> + 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 const struct pci_device_id pci_ids[] __devinitdata = {
> + /* MRST SSP0 */
> + { PCI_VDEVICE(INTEL, 0x0815), QUIRKS_PLATFORM_MRST},
> + /* 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,
> +};
> +
> +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/intel_mid_ssp_spi.h b/drivers/spi/intel_mid_ssp_spi.h
> new file mode 100644
> index 0000000..aef2fa8
> --- /dev/null
> +++ b/drivers/spi/intel_mid_ssp_spi.h
> @@ -0,0 +1,321 @@
> +/*
> + * Copyright (C) Intel 2009
> + * Ken Mills <ken.k.mills@intel.com>
> + * Sylvain Centelles <sylvain.centelles@intel.com>
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + *
> + * 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 INTEL_MID_SSP_SPI_H_
> +#define INTEL_MID_SSP_SPI_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_SRAM_ADDITIONAL_CPY 1
> +/* If set the trailing bytes won't be handled by the DMA. */
> +/* Trailing byte feature not fully available. */
> +#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 Moorestown */
> +#define QUIRKS_PLATFORM_MRST 8
> +/* This quirks is set on Medfield */
> +#define QUIRKS_PLATFORM_MDFL 16
> +/* If set, the driver will apply the bitbanging workarround needed */
> +/* to enable defective Langwell stepping A SSP. The defective SSP */
> +/* can be enabled only once, and should never be disabled. */
> +#define QUIRKS_BIT_BANGING 32
> +/* 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;
> +
> + /* I2C registers */
> + dma_addr_t I2C_paddr;
> + void *I2C_ioaddr;
> +
> + /* SSP masks*/
> + u32 cr1_sig;
> + u32 cr1;
> + u32 clear_sr;
> + u32 mask_sr;
> +
> + /* PM_QOS request */
> + struct pm_qos_request_list pm_qos_req;
> +
> + 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;
> +
> + u8 __iomem *virt_addr_sram_tx;
> + u8 __iomem *virt_addr_sram_rx;
> +
> + 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 /*INTEL_MID_SSP_SPI_H_*/


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