Merge tag 'spi-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi updates from Mark Brown:
 "The major highlight this release is a refactoring of the core to allow
  us to run synchronous transfers in the context of the caller when
  there is no contention for the bus.  This improves performance in the
  very common case by eliminating context switches and reducing the
  number of hardware setup and teardown operations we need to perform.

  Other changes:

   - New drivers for DLN-2 USB-SPI adapter and ST SPI controllers.

   - A big round of cleanups, performance and feature improvements for
     the xilinx driver from Ricardo Ribalda Delgado.

   - A wide range of smaller cleanups, fixes and feature improvements
     throughout the subsystem"

* tag 'spi-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (68 commits)
  spi: mxs: cleanup wait_for_completion return handling
  spi: ti-qspi: cleanup wait_for_completion return handling
  spi: spi-imx: cleanup wait_for_completion handling
  spi: sh-msiof: cleanup wait_for_completion return handling
  spi: match var type to return type of wait_for_completion
  spi: spi-pxa2xx: only include mach/dma.h for legacy DMA
  spi: atmel: cleanup wait_for_completion return handling
  spi: fsl-dspi: Remove possible memory leak of 'chip'
  spi: sh-msiof: Update calculation of frequency dividing
  spi: spidev: Convert buf pointers for 32-bit compat SPI_IOC_MESSAGE(n)
  spi/xilinx: Fix access invalid memory on xilinx_spi_tx
  spi: Revert "spi/xilinx: Remove iowrite/ioread wrappers"
  spi/xilinx: Check number of slaves range
  spi/xilinx: Use polling mode on small transfers
  spi/xilinx: Remove remaining_words driver data variable
  spi/xilinx: Remove iowrite/ioread wrappers
  spi/xilinx: Convert bits_per_word in bytes_per_word
  spi/xilinx: Convert remainding_bytes in remaining words
  spi/xilinx: Make spi_tx and spi_rx simmetric
  spi/xilinx: Remove rx_fn and tx_fn pointer
  ...

48 files changed, 2198 insertions, 697 deletions

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 99829985c1a1..95ccedabba4f 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -185,6 +185,16 @@ config SPI_DAVINCI
 	help
 	  SPI master controller for DaVinci/DA8x/OMAP-L/AM1x SPI modules.
 
+config SPI_DLN2
+       tristate "Diolan DLN-2 USB SPI adapter"
+       depends on MFD_DLN2
+       help
+         If you say yes to this option, support will be included for Diolan
+         DLN2, a USB to SPI interface.
+
+         This driver can also be built as a module.  If so, the module
+         will be called spi-dln2.
+
 config SPI_EFM32
 	tristate "EFM32 SPI controller"
 	depends on OF && ARM && (ARCH_EFM32 || COMPILE_TEST)
@@ -279,7 +289,7 @@ config SPI_FSL_CPM
 	depends on FSL_SOC
 
 config SPI_FSL_SPI
-	bool "Freescale SPI controller and Aeroflex Gaisler GRLIB SPI controller"
+	tristate "Freescale SPI controller and Aeroflex Gaisler GRLIB SPI controller"
 	depends on OF
 	select SPI_FSL_LIB
 	select SPI_FSL_CPM if FSL_SOC
@@ -292,7 +302,6 @@ config SPI_FSL_SPI
 
 config SPI_FSL_DSPI
 	tristate "Freescale DSPI controller"
-	select SPI_BITBANG
 	select REGMAP_MMIO
 	depends on SOC_VF610 || COMPILE_TEST
 	help
@@ -300,7 +309,7 @@ config SPI_FSL_DSPI
 	  mode. VF610 platform uses the controller.
 
 config SPI_FSL_ESPI
-	bool "Freescale eSPI controller"
+	tristate "Freescale eSPI controller"
 	depends on FSL_SOC
 	select SPI_FSL_LIB
 	help
@@ -460,7 +469,6 @@ config SPI_S3C24XX_FIQ
 config SPI_S3C64XX
 	tristate "Samsung S3C64XX series type SPI"
 	depends on (PLAT_SAMSUNG || ARCH_EXYNOS)
-	select S3C64XX_PL080 if ARCH_S3C64XX
 	help
 	  SPI driver for Samsung S3C64XX and newer SoCs.
 
@@ -503,6 +511,13 @@ config SPI_SIRF
 	help
 	  SPI driver for CSR SiRFprimaII SoCs
 
+config SPI_ST_SSC4
+	tristate "STMicroelectronics SPI SSC-based driver"
+	depends on ARCH_STI
+	help
+	  STMicroelectronics SoCs support for SPI. If you say yes to
+	  this option, support will be included for the SSC driven SPI.
+
 config SPI_SUN4I
 	tristate "Allwinner A10 SoCs SPI controller"
 	depends on ARCH_SUNXI || COMPILE_TEST
@@ -595,7 +610,6 @@ config SPI_XTENSA_XTFPGA
 	  16 bit words in SPI mode 0, automatically asserting CS on transfer
 	  start and deasserting on end.
 
-
 config SPI_NUC900
 	tristate "Nuvoton NUC900 series SPI"
 	depends on ARCH_W90X900
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 6b9d2ac629cc..d8cbf654976b 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_SPI_CADENCE)		+= spi-cadence.o
 obj-$(CONFIG_SPI_CLPS711X)		+= spi-clps711x.o
 obj-$(CONFIG_SPI_COLDFIRE_QSPI)		+= spi-coldfire-qspi.o
 obj-$(CONFIG_SPI_DAVINCI)		+= spi-davinci.o
+obj-$(CONFIG_SPI_DLN2)			+= spi-dln2.o
 obj-$(CONFIG_SPI_DESIGNWARE)		+= spi-dw.o
 obj-$(CONFIG_SPI_DW_MMIO)		+= spi-dw-mmio.o
 obj-$(CONFIG_SPI_DW_PCI)		+= spi-dw-midpci.o
@@ -76,6 +77,7 @@ obj-$(CONFIG_SPI_SH_HSPI)		+= spi-sh-hspi.o
 obj-$(CONFIG_SPI_SH_MSIOF)		+= spi-sh-msiof.o
 obj-$(CONFIG_SPI_SH_SCI)		+= spi-sh-sci.o
 obj-$(CONFIG_SPI_SIRF)		+= spi-sirf.o
+obj-$(CONFIG_SPI_ST_SSC4)		+= spi-st-ssc4.o
 obj-$(CONFIG_SPI_SUN4I)			+= spi-sun4i.o
 obj-$(CONFIG_SPI_SUN6I)			+= spi-sun6i.o
 obj-$(CONFIG_SPI_TEGRA114)		+= spi-tegra114.o
diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index 23d8f5f56579..9af7841f2e8c 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -1046,6 +1046,7 @@ static int atmel_spi_one_transfer(struct spi_master *master,
 	struct atmel_spi_device	*asd;
 	int			timeout;
 	int			ret;
+	unsigned long		dma_timeout;
 
 	as = spi_master_get_devdata(master);
 
@@ -1103,15 +1104,12 @@ static int atmel_spi_one_transfer(struct spi_master *master,
 
 		/* interrupts are disabled, so free the lock for schedule */
 		atmel_spi_unlock(as);
-		ret = wait_for_completion_timeout(&as->xfer_completion,
-							SPI_DMA_TIMEOUT);
+		dma_timeout = wait_for_completion_timeout(&as->xfer_completion,
+							  SPI_DMA_TIMEOUT);
 		atmel_spi_lock(as);
-		if (WARN_ON(ret == 0)) {
-			dev_err(&spi->dev,
-				"spi trasfer timeout, err %d\n", ret);
+		if (WARN_ON(dma_timeout == 0)) {
+			dev_err(&spi->dev, "spi transfer timeout\n");
 			as->done_status = -EIO;
-		} else {
-			ret = 0;
 		}
 
 		if (as->done_status)
diff --git a/drivers/spi/spi-au1550.c b/drivers/spi/spi-au1550.c
index 326f47973684..f45e085c01a6 100644
--- a/drivers/spi/spi-au1550.c
+++ b/drivers/spi/spi-au1550.c
@@ -15,10 +15,6 @@
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
 #include <linux/init.h>
diff --git a/drivers/spi/spi-bcm2835.c b/drivers/spi/spi-bcm2835.c
index 98aab457b24d..419a782ab6d5 100644
--- a/drivers/spi/spi-bcm2835.c
+++ b/drivers/spi/spi-bcm2835.c
@@ -17,10 +17,6 @@
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
 #include <linux/clk.h>
diff --git a/drivers/spi/spi-bcm63xx.c b/drivers/spi/spi-bcm63xx.c
index c20530982e26..e73e2b052c9c 100644
--- a/drivers/spi/spi-bcm63xx.c
+++ b/drivers/spi/spi-bcm63xx.c
@@ -13,10 +13,6 @@
  * 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 Street, Fifth Floor,
  */
 
 #include <linux/kernel.h>
diff --git a/drivers/spi/spi-bitbang.c b/drivers/spi/spi-bitbang.c
index dc7d2c2d643e..5ef6638d5e8a 100644
--- a/drivers/spi/spi-bitbang.c
+++ b/drivers/spi/spi-bitbang.c
@@ -10,10 +10,6 @@
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
 #include <linux/spinlock.h>
diff --git a/drivers/spi/spi-butterfly.c b/drivers/spi/spi-butterfly.c
index ee4f91ccd8fd..9a95862986c8 100644
--- a/drivers/spi/spi-butterfly.c
+++ b/drivers/spi/spi-butterfly.c
@@ -12,10 +12,6 @@
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 #include <linux/kernel.h>
 #include <linux/init.h>
diff --git a/drivers/spi/spi-coldfire-qspi.c b/drivers/spi/spi-coldfire-qspi.c
index 41b5dc4445f6..688956ff5095 100644
--- a/drivers/spi/spi-coldfire-qspi.c
+++ b/drivers/spi/spi-coldfire-qspi.c
@@ -12,11 +12,6 @@
  * 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
- *
 */
 
 #include <linux/kernel.h>
diff --git a/drivers/spi/spi-davinci.c b/drivers/spi/spi-davinci.c
index b3707badb1e5..5e991065f5b0 100644
--- a/drivers/spi/spi-davinci.c
+++ b/drivers/spi/spi-davinci.c
@@ -11,10 +11,6 @@
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
 #include <linux/interrupt.h>
diff --git a/drivers/spi/spi-dln2.c b/drivers/spi/spi-dln2.c
new file mode 100644
index 000000000000..3b7d91d94fea
--- /dev/null
+++ b/drivers/spi/spi-dln2.c
@@ -0,0 +1,881 @@
+/*
+ * Driver for the Diolan DLN-2 USB-SPI adapter
+ *
+ * Copyright (c) 2014 Intel Corporation
+ *
+ * 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, version 2.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/dln2.h>
+#include <linux/spi/spi.h>
+#include <linux/pm_runtime.h>
+#include <asm/unaligned.h>
+
+#define DLN2_SPI_MODULE_ID		0x02
+#define DLN2_SPI_CMD(cmd)		DLN2_CMD(cmd, DLN2_SPI_MODULE_ID)
+
+/* SPI commands */
+#define DLN2_SPI_GET_PORT_COUNT			DLN2_SPI_CMD(0x00)
+#define DLN2_SPI_ENABLE				DLN2_SPI_CMD(0x11)
+#define DLN2_SPI_DISABLE			DLN2_SPI_CMD(0x12)
+#define DLN2_SPI_IS_ENABLED			DLN2_SPI_CMD(0x13)
+#define DLN2_SPI_SET_MODE			DLN2_SPI_CMD(0x14)
+#define DLN2_SPI_GET_MODE			DLN2_SPI_CMD(0x15)
+#define DLN2_SPI_SET_FRAME_SIZE			DLN2_SPI_CMD(0x16)
+#define DLN2_SPI_GET_FRAME_SIZE			DLN2_SPI_CMD(0x17)
+#define DLN2_SPI_SET_FREQUENCY			DLN2_SPI_CMD(0x18)
+#define DLN2_SPI_GET_FREQUENCY			DLN2_SPI_CMD(0x19)
+#define DLN2_SPI_READ_WRITE			DLN2_SPI_CMD(0x1A)
+#define DLN2_SPI_READ				DLN2_SPI_CMD(0x1B)
+#define DLN2_SPI_WRITE				DLN2_SPI_CMD(0x1C)
+#define DLN2_SPI_SET_DELAY_BETWEEN_SS		DLN2_SPI_CMD(0x20)
+#define DLN2_SPI_GET_DELAY_BETWEEN_SS		DLN2_SPI_CMD(0x21)
+#define DLN2_SPI_SET_DELAY_AFTER_SS		DLN2_SPI_CMD(0x22)
+#define DLN2_SPI_GET_DELAY_AFTER_SS		DLN2_SPI_CMD(0x23)
+#define DLN2_SPI_SET_DELAY_BETWEEN_FRAMES	DLN2_SPI_CMD(0x24)
+#define DLN2_SPI_GET_DELAY_BETWEEN_FRAMES	DLN2_SPI_CMD(0x25)
+#define DLN2_SPI_SET_SS				DLN2_SPI_CMD(0x26)
+#define DLN2_SPI_GET_SS				DLN2_SPI_CMD(0x27)
+#define DLN2_SPI_RELEASE_SS			DLN2_SPI_CMD(0x28)
+#define DLN2_SPI_SS_VARIABLE_ENABLE		DLN2_SPI_CMD(0x2B)
+#define DLN2_SPI_SS_VARIABLE_DISABLE		DLN2_SPI_CMD(0x2C)
+#define DLN2_SPI_SS_VARIABLE_IS_ENABLED		DLN2_SPI_CMD(0x2D)
+#define DLN2_SPI_SS_AAT_ENABLE			DLN2_SPI_CMD(0x2E)
+#define DLN2_SPI_SS_AAT_DISABLE			DLN2_SPI_CMD(0x2F)
+#define DLN2_SPI_SS_AAT_IS_ENABLED		DLN2_SPI_CMD(0x30)
+#define DLN2_SPI_SS_BETWEEN_FRAMES_ENABLE	DLN2_SPI_CMD(0x31)
+#define DLN2_SPI_SS_BETWEEN_FRAMES_DISABLE	DLN2_SPI_CMD(0x32)
+#define DLN2_SPI_SS_BETWEEN_FRAMES_IS_ENABLED	DLN2_SPI_CMD(0x33)
+#define DLN2_SPI_SET_CPHA			DLN2_SPI_CMD(0x34)
+#define DLN2_SPI_GET_CPHA			DLN2_SPI_CMD(0x35)
+#define DLN2_SPI_SET_CPOL			DLN2_SPI_CMD(0x36)
+#define DLN2_SPI_GET_CPOL			DLN2_SPI_CMD(0x37)
+#define DLN2_SPI_SS_MULTI_ENABLE		DLN2_SPI_CMD(0x38)
+#define DLN2_SPI_SS_MULTI_DISABLE		DLN2_SPI_CMD(0x39)
+#define DLN2_SPI_SS_MULTI_IS_ENABLED		DLN2_SPI_CMD(0x3A)
+#define DLN2_SPI_GET_SUPPORTED_MODES		DLN2_SPI_CMD(0x40)
+#define DLN2_SPI_GET_SUPPORTED_CPHA_VALUES	DLN2_SPI_CMD(0x41)
+#define DLN2_SPI_GET_SUPPORTED_CPOL_VALUES	DLN2_SPI_CMD(0x42)
+#define DLN2_SPI_GET_SUPPORTED_FRAME_SIZES	DLN2_SPI_CMD(0x43)
+#define DLN2_SPI_GET_SS_COUNT			DLN2_SPI_CMD(0x44)
+#define DLN2_SPI_GET_MIN_FREQUENCY		DLN2_SPI_CMD(0x45)
+#define DLN2_SPI_GET_MAX_FREQUENCY		DLN2_SPI_CMD(0x46)
+#define DLN2_SPI_GET_MIN_DELAY_BETWEEN_SS	DLN2_SPI_CMD(0x47)
+#define DLN2_SPI_GET_MAX_DELAY_BETWEEN_SS	DLN2_SPI_CMD(0x48)
+#define DLN2_SPI_GET_MIN_DELAY_AFTER_SS		DLN2_SPI_CMD(0x49)
+#define DLN2_SPI_GET_MAX_DELAY_AFTER_SS		DLN2_SPI_CMD(0x4A)
+#define DLN2_SPI_GET_MIN_DELAY_BETWEEN_FRAMES	DLN2_SPI_CMD(0x4B)
+#define DLN2_SPI_GET_MAX_DELAY_BETWEEN_FRAMES	DLN2_SPI_CMD(0x4C)
+
+#define DLN2_SPI_MAX_XFER_SIZE			256
+#define DLN2_SPI_BUF_SIZE			(DLN2_SPI_MAX_XFER_SIZE + 16)
+#define DLN2_SPI_ATTR_LEAVE_SS_LOW		BIT(0)
+#define DLN2_TRANSFERS_WAIT_COMPLETE		1
+#define DLN2_TRANSFERS_CANCEL			0
+#define DLN2_RPM_AUTOSUSPEND_TIMEOUT		2000
+
+struct dln2_spi {
+	struct platform_device *pdev;
+	struct spi_master *master;
+	u8 port;
+
+	/*
+	 * This buffer will be used mainly for read/write operations. Since
+	 * they're quite large, we cannot use the stack. Protection is not
+	 * needed because all SPI communication is serialized by the SPI core.
+	 */
+	void *buf;
+
+	u8 bpw;
+	u32 speed;
+	u16 mode;
+	u8 cs;
+};
+
+/*
+ * Enable/Disable SPI module. The disable command will wait for transfers to
+ * complete first.
+ */
+static int dln2_spi_enable(struct dln2_spi *dln2, bool enable)
+{
+	u16 cmd;
+	struct {
+		u8 port;
+		u8 wait_for_completion;
+	} tx;
+	unsigned len = sizeof(tx);
+
+	tx.port = dln2->port;
+
+	if (enable) {
+		cmd = DLN2_SPI_ENABLE;
+		len -= sizeof(tx.wait_for_completion);
+	} else {
+		tx.wait_for_completion = DLN2_TRANSFERS_WAIT_COMPLETE;
+		cmd = DLN2_SPI_DISABLE;
+	}
+
+	return dln2_transfer_tx(dln2->pdev, cmd, &tx, len);
+}
+
+/*
+ * Select/unselect multiple CS lines. The selected lines will be automatically
+ * toggled LOW/HIGH by the board firmware during transfers, provided they're
+ * enabled first.
+ *
+ * Ex: cs_mask = 0x03 -> CS0 & CS1 will be selected and the next WR/RD operation
+ *                       will toggle the lines LOW/HIGH automatically.
+ */
+static int dln2_spi_cs_set(struct dln2_spi *dln2, u8 cs_mask)
+{
+	struct {
+		u8 port;
+		u8 cs;
+	} tx;
+
+	tx.port = dln2->port;
+
+	/*
+	 * According to Diolan docs, "a slave device can be selected by changing
+	 * the corresponding bit value to 0". The rest must be set to 1. Hence
+	 * the bitwise NOT in front.
+	 */
+	tx.cs = ~cs_mask;
+
+	return dln2_transfer_tx(dln2->pdev, DLN2_SPI_SET_SS, &tx, sizeof(tx));
+}
+
+/*
+ * Select one CS line. The other lines will be un-selected.
+ */
+static int dln2_spi_cs_set_one(struct dln2_spi *dln2, u8 cs)
+{
+	return dln2_spi_cs_set(dln2, BIT(cs));
+}
+
+/*
+ * Enable/disable CS lines for usage. The module has to be disabled first.
+ */
+static int dln2_spi_cs_enable(struct dln2_spi *dln2, u8 cs_mask, bool enable)
+{
+	struct {
+		u8 port;
+		u8 cs;
+	} tx;
+	u16 cmd;
+
+	tx.port = dln2->port;
+	tx.cs = cs_mask;
+	cmd = enable ? DLN2_SPI_SS_MULTI_ENABLE : DLN2_SPI_SS_MULTI_DISABLE;
+
+	return dln2_transfer_tx(dln2->pdev, cmd, &tx, sizeof(tx));
+}
+
+static int dln2_spi_cs_enable_all(struct dln2_spi *dln2, bool enable)
+{
+	u8 cs_mask = GENMASK(dln2->master->num_chipselect - 1, 0);
+
+	return dln2_spi_cs_enable(dln2, cs_mask, enable);
+}
+
+static int dln2_spi_get_cs_num(struct dln2_spi *dln2, u16 *cs_num)
+{
+	int ret;
+	struct {
+		u8 port;
+	} tx;
+	struct {
+		__le16 cs_count;
+	} rx;
+	unsigned rx_len = sizeof(rx);
+
+	tx.port = dln2->port;
+	ret = dln2_transfer(dln2->pdev, DLN2_SPI_GET_SS_COUNT, &tx, sizeof(tx),
+			    &rx, &rx_len);
+	if (ret < 0)
+		return ret;
+	if (rx_len < sizeof(rx))
+		return -EPROTO;
+
+	*cs_num = le16_to_cpu(rx.cs_count);
+
+	dev_dbg(&dln2->pdev->dev, "cs_num = %d\n", *cs_num);
+
+	return 0;
+}
+
+static int dln2_spi_get_speed(struct dln2_spi *dln2, u16 cmd, u32 *freq)
+{
+	int ret;
+	struct {
+		u8 port;
+	} tx;
+	struct {
+		__le32 speed;
+	} rx;
+	unsigned rx_len = sizeof(rx);
+
+	tx.port = dln2->port;
+
+	ret = dln2_transfer(dln2->pdev, cmd, &tx, sizeof(tx), &rx, &rx_len);
+	if (ret < 0)
+		return ret;
+	if (rx_len < sizeof(rx))
+		return -EPROTO;
+
+	*freq = le32_to_cpu(rx.speed);
+
+	return 0;
+}
+
+/*
+ * Get bus min/max frequencies.
+ */
+static int dln2_spi_get_speed_range(struct dln2_spi *dln2, u32 *fmin, u32 *fmax)
+{
+	int ret;
+
+	ret = dln2_spi_get_speed(dln2, DLN2_SPI_GET_MIN_FREQUENCY, fmin);
+	if (ret < 0)
+		return ret;
+
+	ret = dln2_spi_get_speed(dln2, DLN2_SPI_GET_MAX_FREQUENCY, fmax);
+	if (ret < 0)
+		return ret;
+
+	dev_dbg(&dln2->pdev->dev, "freq_min = %d, freq_max = %d\n",
+		*fmin, *fmax);
+
+	return 0;
+}
+
+/*
+ * Set the bus speed. The module will automatically round down to the closest
+ * available frequency and returns it. The module has to be disabled first.
+ */
+static int dln2_spi_set_speed(struct dln2_spi *dln2, u32 speed)
+{
+	int ret;
+	struct {
+		u8 port;
+		__le32 speed;
+	} __packed tx;
+	struct {
+		__le32 speed;
+	} rx;
+	int rx_len = sizeof(rx);
+
+	tx.port = dln2->port;
+	tx.speed = cpu_to_le32(speed);
+
+	ret = dln2_transfer(dln2->pdev, DLN2_SPI_SET_FREQUENCY, &tx, sizeof(tx),
+			    &rx, &rx_len);
+	if (ret < 0)
+		return ret;
+	if (rx_len < sizeof(rx))
+		return -EPROTO;
+
+	return 0;
+}
+
+/*
+ * Change CPOL & CPHA. The module has to be disabled first.
+ */
+static int dln2_spi_set_mode(struct dln2_spi *dln2, u8 mode)
+{
+	struct {
+		u8 port;
+		u8 mode;
+	} tx;
+
+	tx.port = dln2->port;
+	tx.mode = mode;
+
+	return dln2_transfer_tx(dln2->pdev, DLN2_SPI_SET_MODE, &tx, sizeof(tx));
+}
+
+/*
+ * Change frame size. The module has to be disabled first.
+ */
+static int dln2_spi_set_bpw(struct dln2_spi *dln2, u8 bpw)
+{
+	struct {
+		u8 port;
+		u8 bpw;
+	} tx;
+
+	tx.port = dln2->port;
+	tx.bpw = bpw;
+
+	return dln2_transfer_tx(dln2->pdev, DLN2_SPI_SET_FRAME_SIZE,
+				&tx, sizeof(tx));
+}
+
+static int dln2_spi_get_supported_frame_sizes(struct dln2_spi *dln2,
+					      u32 *bpw_mask)
+{
+	int ret;
+	struct {
+		u8 port;
+	} tx;
+	struct {
+		u8 count;
+		u8 frame_sizes[36];
+	} *rx = dln2->buf;
+	unsigned rx_len = sizeof(*rx);
+	int i;
+
+	tx.port = dln2->port;
+
+	ret = dln2_transfer(dln2->pdev, DLN2_SPI_GET_SUPPORTED_FRAME_SIZES,
+			    &tx, sizeof(tx), rx, &rx_len);
+	if (ret < 0)
+		return ret;
+	if (rx_len < sizeof(*rx))
+		return -EPROTO;
+	if (rx->count > ARRAY_SIZE(rx->frame_sizes))
+		return -EPROTO;
+
+	*bpw_mask = 0;
+	for (i = 0; i < rx->count; i++)
+		*bpw_mask |= BIT(rx->frame_sizes[i] - 1);
+
+	dev_dbg(&dln2->pdev->dev, "bpw_mask = 0x%X\n", *bpw_mask);
+
+	return 0;
+}
+
+/*
+ * Copy the data to DLN2 buffer and change the byte order to LE, requested by
+ * DLN2 module. SPI core makes sure that the data length is a multiple of word
+ * size.
+ */
+static int dln2_spi_copy_to_buf(u8 *dln2_buf, const u8 *src, u16 len, u8 bpw)
+{
+#ifdef __LITTLE_ENDIAN
+	memcpy(dln2_buf, src, len);
+#else
+	if (bpw <= 8) {
+		memcpy(dln2_buf, src, len);
+	} else if (bpw <= 16) {
+		__le16 *d = (__le16 *)dln2_buf;
+		u16 *s = (u16 *)src;
+
+		len = len / 2;
+		while (len--)
+			*d++ = cpu_to_le16p(s++);
+	} else {
+		__le32 *d = (__le32 *)dln2_buf;
+		u32 *s = (u32 *)src;
+
+		len = len / 4;
+		while (len--)
+			*d++ = cpu_to_le32p(s++);
+	}
+#endif
+
+	return 0;
+}
+
+/*
+ * Copy the data from DLN2 buffer and convert to CPU byte order since the DLN2
+ * buffer is LE ordered. SPI core makes sure that the data length is a multiple
+ * of word size. The RX dln2_buf is 2 byte aligned so, for BE, we have to make
+ * sure we avoid unaligned accesses for 32 bit case.
+ */
+static int dln2_spi_copy_from_buf(u8 *dest, const u8 *dln2_buf, u16 len, u8 bpw)
+{
+#ifdef __LITTLE_ENDIAN
+	memcpy(dest, dln2_buf, len);
+#else
+	if (bpw <= 8) {
+		memcpy(dest, dln2_buf, len);
+	} else if (bpw <= 16) {
+		u16 *d = (u16 *)dest;
+		__le16 *s = (__le16 *)dln2_buf;
+
+		len = len / 2;
+		while (len--)
+			*d++ = le16_to_cpup(s++);
+	} else {
+		u32 *d = (u32 *)dest;
+		__le32 *s = (__le32 *)dln2_buf;
+
+		len = len / 4;
+		while (len--)
+			*d++ = get_unaligned_le32(s++);
+	}
+#endif
+
+	return 0;
+}
+
+/*
+ * Perform one write operation.
+ */
+static int dln2_spi_write_one(struct dln2_spi *dln2, const u8 *data,
+			      u16 data_len, u8 attr)
+{
+	struct {
+		u8 port;
+		__le16 size;
+		u8 attr;
+		u8 buf[DLN2_SPI_MAX_XFER_SIZE];
+	} __packed *tx = dln2->buf;
+	unsigned tx_len;
+
+	BUILD_BUG_ON(sizeof(*tx) > DLN2_SPI_BUF_SIZE);
+
+	if (data_len > DLN2_SPI_MAX_XFER_SIZE)
+		return -EINVAL;
+
+	tx->port = dln2->port;
+	tx->size = cpu_to_le16(data_len);
+	tx->attr = attr;
+
+	dln2_spi_copy_to_buf(tx->buf, data, data_len, dln2->bpw);
+
+	tx_len = sizeof(*tx) + data_len - DLN2_SPI_MAX_XFER_SIZE;
+	return dln2_transfer_tx(dln2->pdev, DLN2_SPI_WRITE, tx, tx_len);
+}
+
+/*
+ * Perform one read operation.
+ */
+static int dln2_spi_read_one(struct dln2_spi *dln2, u8 *data,
+			     u16 data_len, u8 attr)
+{
+	int ret;
+	struct {
+		u8 port;
+		__le16 size;
+		u8 attr;
+	} __packed tx;
+	struct {
+		__le16