Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2453 insertions, 0 deletions

diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c
new file mode 100644
index 000000000..e4484ace5
--- /dev/null
+++ b/drivers/spi/spi-pl022.c
@@ -0,0 +1,2453 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * A driver for the ARM PL022 PrimeCell SSP/SPI bus master.
+ *
+ * Copyright (C) 2008-2012 ST-Ericsson AB
+ * Copyright (C) 2006 STMicroelectronics Pvt. Ltd.
+ *
+ * Author: Linus Walleij <linus.walleij@stericsson.com>
+ *
+ * Initial version inspired by:
+ *	linux-2.6.17-rc3-mm1/drivers/spi/pxa2xx_spi.c
+ * Initial adoption to PL022 by:
+ *      Sachin Verma <sachin.verma@st.com>
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/ioport.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/spi/spi.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/amba/bus.h>
+#include <linux/amba/pl022.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/scatterlist.h>
+#include <linux/pm_runtime.h>
+#include <linux/of.h>
+#include <linux/pinctrl/consumer.h>
+
+/*
+ * This macro is used to define some register default values.
+ * reg is masked with mask, the OR:ed with an (again masked)
+ * val shifted sb steps to the left.
+ */
+#define SSP_WRITE_BITS(reg, val, mask, sb) \
+ ((reg) = (((reg) & ~(mask)) | (((val)<<(sb)) & (mask))))
+
+/*
+ * This macro is also used to define some default values.
+ * It will just shift val by sb steps to the left and mask
+ * the result with mask.
+ */
+#define GEN_MASK_BITS(val, mask, sb) \
+ (((val)<<(sb)) & (mask))
+
+#define DRIVE_TX		0
+#define DO_NOT_DRIVE_TX		1
+
+#define DO_NOT_QUEUE_DMA	0
+#define QUEUE_DMA		1
+
+#define RX_TRANSFER		1
+#define TX_TRANSFER		2
+
+/*
+ * Macros to access SSP Registers with their offsets
+ */
+#define SSP_CR0(r)	(r + 0x000)
+#define SSP_CR1(r)	(r + 0x004)
+#define SSP_DR(r)	(r + 0x008)
+#define SSP_SR(r)	(r + 0x00C)
+#define SSP_CPSR(r)	(r + 0x010)
+#define SSP_IMSC(r)	(r + 0x014)
+#define SSP_RIS(r)	(r + 0x018)
+#define SSP_MIS(r)	(r + 0x01C)
+#define SSP_ICR(r)	(r + 0x020)
+#define SSP_DMACR(r)	(r + 0x024)
+#define SSP_CSR(r)	(r + 0x030) /* vendor extension */
+#define SSP_ITCR(r)	(r + 0x080)
+#define SSP_ITIP(r)	(r + 0x084)
+#define SSP_ITOP(r)	(r + 0x088)
+#define SSP_TDR(r)	(r + 0x08C)
+
+#define SSP_PID0(r)	(r + 0xFE0)
+#define SSP_PID1(r)	(r + 0xFE4)
+#define SSP_PID2(r)	(r + 0xFE8)
+#define SSP_PID3(r)	(r + 0xFEC)
+
+#define SSP_CID0(r)	(r + 0xFF0)
+#define SSP_CID1(r)	(r + 0xFF4)
+#define SSP_CID2(r)	(r + 0xFF8)
+#define SSP_CID3(r)	(r + 0xFFC)
+
+/*
+ * SSP Control Register 0  - SSP_CR0
+ */
+#define SSP_CR0_MASK_DSS	(0x0FUL << 0)
+#define SSP_CR0_MASK_FRF	(0x3UL << 4)
+#define SSP_CR0_MASK_SPO	(0x1UL << 6)
+#define SSP_CR0_MASK_SPH	(0x1UL << 7)
+#define SSP_CR0_MASK_SCR	(0xFFUL << 8)
+
+/*
+ * The ST version of this block moves som bits
+ * in SSP_CR0 and extends it to 32 bits
+ */
+#define SSP_CR0_MASK_DSS_ST	(0x1FUL << 0)
+#define SSP_CR0_MASK_HALFDUP_ST	(0x1UL << 5)
+#define SSP_CR0_MASK_CSS_ST	(0x1FUL << 16)
+#define SSP_CR0_MASK_FRF_ST	(0x3UL << 21)
+
+/*
+ * SSP Control Register 0  - SSP_CR1
+ */
+#define SSP_CR1_MASK_LBM	(0x1UL << 0)
+#define SSP_CR1_MASK_SSE	(0x1UL << 1)
+#define SSP_CR1_MASK_MS		(0x1UL << 2)
+#define SSP_CR1_MASK_SOD	(0x1UL << 3)
+
+/*
+ * The ST version of this block adds some bits
+ * in SSP_CR1
+ */
+#define SSP_CR1_MASK_RENDN_ST	(0x1UL << 4)
+#define SSP_CR1_MASK_TENDN_ST	(0x1UL << 5)
+#define SSP_CR1_MASK_MWAIT_ST	(0x1UL << 6)
+#define SSP_CR1_MASK_RXIFLSEL_ST (0x7UL << 7)
+#define SSP_CR1_MASK_TXIFLSEL_ST (0x7UL << 10)
+/* This one is only in the PL023 variant */
+#define SSP_CR1_MASK_FBCLKDEL_ST (0x7UL << 13)
+
+/*
+ * SSP Status Register - SSP_SR
+ */
+#define SSP_SR_MASK_TFE		(0x1UL << 0) /* Transmit FIFO empty */
+#define SSP_SR_MASK_TNF		(0x1UL << 1) /* Transmit FIFO not full */
+#define SSP_SR_MASK_RNE		(0x1UL << 2) /* Receive FIFO not empty */
+#define SSP_SR_MASK_RFF		(0x1UL << 3) /* Receive FIFO full */
+#define SSP_SR_MASK_BSY		(0x1UL << 4) /* Busy Flag */
+
+/*
+ * SSP Clock Prescale Register  - SSP_CPSR
+ */
+#define SSP_CPSR_MASK_CPSDVSR	(0xFFUL << 0)
+
+/*
+ * SSP Interrupt Mask Set/Clear Register - SSP_IMSC
+ */
+#define SSP_IMSC_MASK_RORIM (0x1UL << 0) /* Receive Overrun Interrupt mask */
+#define SSP_IMSC_MASK_RTIM  (0x1UL << 1) /* Receive timeout Interrupt mask */
+#define SSP_IMSC_MASK_RXIM  (0x1UL << 2) /* Receive FIFO Interrupt mask */
+#define SSP_IMSC_MASK_TXIM  (0x1UL << 3) /* Transmit FIFO Interrupt mask */
+
+/*
+ * SSP Raw Interrupt Status Register - SSP_RIS
+ */
+/* Receive Overrun Raw Interrupt status */
+#define SSP_RIS_MASK_RORRIS		(0x1UL << 0)
+/* Receive Timeout Raw Interrupt status */
+#define SSP_RIS_MASK_RTRIS		(0x1UL << 1)
+/* Receive FIFO Raw Interrupt status */
+#define SSP_RIS_MASK_RXRIS		(0x1UL << 2)
+/* Transmit FIFO Raw Interrupt status */
+#define SSP_RIS_MASK_TXRIS		(0x1UL << 3)
+
+/*
+ * SSP Masked Interrupt Status Register - SSP_MIS
+ */
+/* Receive Overrun Masked Interrupt status */
+#define SSP_MIS_MASK_RORMIS		(0x1UL << 0)
+/* Receive Timeout Masked Interrupt status */
+#define SSP_MIS_MASK_RTMIS		(0x1UL << 1)
+/* Receive FIFO Masked Interrupt status */
+#define SSP_MIS_MASK_RXMIS		(0x1UL << 2)
+/* Transmit FIFO Masked Interrupt status */
+#define SSP_MIS_MASK_TXMIS		(0x1UL << 3)
+
+/*
+ * SSP Interrupt Clear Register - SSP_ICR
+ */
+/* Receive Overrun Raw Clear Interrupt bit */
+#define SSP_ICR_MASK_RORIC		(0x1UL << 0)
+/* Receive Timeout Clear Interrupt bit */
+#define SSP_ICR_MASK_RTIC		(0x1UL << 1)
+
+/*
+ * SSP DMA Control Register - SSP_DMACR
+ */
+/* Receive DMA Enable bit */
+#define SSP_DMACR_MASK_RXDMAE		(0x1UL << 0)
+/* Transmit DMA Enable bit */
+#define SSP_DMACR_MASK_TXDMAE		(0x1UL << 1)
+
+/*
+ * SSP Chip Select Control Register - SSP_CSR
+ * (vendor extension)
+ */
+#define SSP_CSR_CSVALUE_MASK		(0x1FUL << 0)
+
+/*
+ * SSP Integration Test control Register - SSP_ITCR
+ */
+#define SSP_ITCR_MASK_ITEN		(0x1UL << 0)
+#define SSP_ITCR_MASK_TESTFIFO		(0x1UL << 1)
+
+/*
+ * SSP Integration Test Input Register - SSP_ITIP
+ */
+#define ITIP_MASK_SSPRXD		 (0x1UL << 0)
+#define ITIP_MASK_SSPFSSIN		 (0x1UL << 1)
+#define ITIP_MASK_SSPCLKIN		 (0x1UL << 2)
+#define ITIP_MASK_RXDMAC		 (0x1UL << 3)
+#define ITIP_MASK_TXDMAC		 (0x1UL << 4)
+#define ITIP_MASK_SSPTXDIN		 (0x1UL << 5)
+
+/*
+ * SSP Integration Test output Register - SSP_ITOP
+ */
+#define ITOP_MASK_SSPTXD		 (0x1UL << 0)
+#define ITOP_MASK_SSPFSSOUT		 (0x1UL << 1)
+#define ITOP_MASK_SSPCLKOUT		 (0x1UL << 2)
+#define ITOP_MASK_SSPOEn		 (0x1UL << 3)
+#define ITOP_MASK_SSPCTLOEn		 (0x1UL << 4)
+#define ITOP_MASK_RORINTR		 (0x1UL << 5)
+#define ITOP_MASK_RTINTR		 (0x1UL << 6)
+#define ITOP_MASK_RXINTR		 (0x1UL << 7)
+#define ITOP_MASK_TXINTR		 (0x1UL << 8)
+#define ITOP_MASK_INTR			 (0x1UL << 9)
+#define ITOP_MASK_RXDMABREQ		 (0x1UL << 10)
+#define ITOP_MASK_RXDMASREQ		 (0x1UL << 11)
+#define ITOP_MASK_TXDMABREQ		 (0x1UL << 12)
+#define ITOP_MASK_TXDMASREQ		 (0x1UL << 13)
+
+/*
+ * SSP Test Data Register - SSP_TDR
+ */
+#define TDR_MASK_TESTDATA		(0xFFFFFFFF)
+
+/*
+ * Message State
+ * we use the spi_message.state (void *) pointer to
+ * hold a single state value, that's why all this
+ * (void *) casting is done here.
+ */
+#define STATE_START			((void *) 0)
+#define STATE_RUNNING			((void *) 1)
+#define STATE_DONE			((void *) 2)
+#define STATE_ERROR			((void *) -1)
+#define STATE_TIMEOUT			((void *) -2)
+
+/*
+ * SSP State - Whether Enabled or Disabled
+ */
+#define SSP_DISABLED			(0)
+#define SSP_ENABLED			(1)
+
+/*
+ * SSP DMA State - Whether DMA Enabled or Disabled
+ */
+#define SSP_DMA_DISABLED		(0)
+#define SSP_DMA_ENABLED			(1)
+
+/*
+ * SSP Clock Defaults
+ */
+#define SSP_DEFAULT_CLKRATE 0x2
+#define SSP_DEFAULT_PRESCALE 0x40
+
+/*
+ * SSP Clock Parameter ranges
+ */
+#define CPSDVR_MIN 0x02
+#define CPSDVR_MAX 0xFE
+#define SCR_MIN 0x00
+#define SCR_MAX 0xFF
+
+/*
+ * SSP Interrupt related Macros
+ */
+#define DEFAULT_SSP_REG_IMSC  0x0UL
+#define DISABLE_ALL_INTERRUPTS DEFAULT_SSP_REG_IMSC
+#define ENABLE_ALL_INTERRUPTS ( \
+	SSP_IMSC_MASK_RORIM | \
+	SSP_IMSC_MASK_RTIM | \
+	SSP_IMSC_MASK_RXIM | \
+	SSP_IMSC_MASK_TXIM \
+)
+
+#define CLEAR_ALL_INTERRUPTS  0x3
+
+#define SPI_POLLING_TIMEOUT 1000
+
+/*
+ * The type of reading going on this chip
+ */
+enum ssp_reading {
+	READING_NULL,
+	READING_U8,
+	READING_U16,
+	READING_U32
+};
+
+/*
+ * The type of writing going on this chip
+ */
+enum ssp_writing {
+	WRITING_NULL,
+	WRITING_U8,
+	WRITING_U16,
+	WRITING_U32
+};
+
+/**
+ * struct vendor_data - vendor-specific config parameters
+ * for PL022 derivates
+ * @fifodepth: depth of FIFOs (both)
+ * @max_bpw: maximum number of bits per word
+ * @unidir: supports unidirection transfers
+ * @extended_cr: 32 bit wide control register 0 with extra
+ * features and extra features in CR1 as found in the ST variants
+ * @pl023: supports a subset of the ST extensions called "PL023"
+ * @loopback: supports loopback mode
+ * @internal_cs_ctrl: supports chip select control register
+ */
+struct vendor_data {
+	int fifodepth;
+	int max_bpw;
+	bool unidir;
+	bool extended_cr;
+	bool pl023;
+	bool loopback;
+	bool internal_cs_ctrl;
+};
+
+/**
+ * struct pl022 - This is the private SSP driver data structure
+ * @adev: AMBA device model hookup
+ * @vendor: vendor data for the IP block
+ * @phybase: the physical memory where the SSP device resides
+ * @virtbase: the virtual memory where the SSP is mapped
+ * @clk: outgoing clock "SPICLK" for the SPI bus
+ * @master: SPI framework hookup
+ * @master_info: controller-specific data from machine setup
+ * @pump_transfers: Tasklet used in Interrupt Transfer mode
+ * @cur_msg: Pointer to current spi_message being processed
+ * @cur_transfer: Pointer to current spi_transfer
+ * @cur_chip: pointer to current clients chip(assigned from controller_state)
+ * @next_msg_cs_active: the next message in the queue has been examined
+ *  and it was found that it uses the same chip select as the previous
+ *  message, so we left it active after the previous transfer, and it's
+ *  active already.
+ * @tx: current position in TX buffer to be read
+ * @tx_end: end position in TX buffer to be read
+ * @rx: current position in RX buffer to be written
+ * @rx_end: end position in RX buffer to be written
+ * @read: the type of read currently going on
+ * @write: the type of write currently going on
+ * @exp_fifo_level: expected FIFO level
+ * @rx_lev_trig: receive FIFO watermark level which triggers IRQ
+ * @tx_lev_trig: transmit FIFO watermark level which triggers IRQ
+ * @dma_rx_channel: optional channel for RX DMA
+ * @dma_tx_channel: optional channel for TX DMA
+ * @sgt_rx: scattertable for the RX transfer
+ * @sgt_tx: scattertable for the TX transfer
+ * @dummypage: a dummy page used for driving data on the bus with DMA
+ * @dma_running: indicates whether DMA is in operation
+ * @cur_cs: current chip select index
+ * @cur_gpiod: current chip select GPIO descriptor
+ */
+struct pl022 {
+	struct amba_device		*adev;
+	struct vendor_data		*vendor;
+	resource_size_t			phybase;
+	void __iomem			*virtbase;
+	struct clk			*clk;
+	struct spi_master		*master;
+	struct pl022_ssp_controller	*master_info;
+	/* Message per-transfer pump */
+	struct tasklet_struct		pump_transfers;
+	struct spi_message		*cur_msg;
+	struct spi_transfer		*cur_transfer;
+	struct chip_data		*cur_chip;
+	bool				next_msg_cs_active;
+	void				*tx;
+	void				*tx_end;
+	void				*rx;
+	void				*rx_end;
+	enum ssp_reading		read;
+	enum ssp_writing		write;
+	u32				exp_fifo_level;
+	enum ssp_rx_level_trig		rx_lev_trig;
+	enum ssp_tx_level_trig		tx_lev_trig;
+	/* DMA settings */
+#ifdef CONFIG_DMA_ENGINE
+	struct dma_chan			*dma_rx_channel;
+	struct dma_chan			*dma_tx_channel;
+	struct sg_table			sgt_rx;
+	struct sg_table			sgt_tx;
+	char				*dummypage;
+	bool				dma_running;
+#endif
+	int cur_cs;
+	struct gpio_desc *cur_gpiod;
+};
+
+/**
+ * struct chip_data - To maintain runtime state of SSP for each client chip
+ * @cr0: Value of control register CR0 of SSP - on later ST variants this
+ *       register is 32 bits wide rather than just 16
+ * @cr1: Value of control register CR1 of SSP
+ * @dmacr: Value of DMA control Register of SSP
+ * @cpsr: Value of Clock prescale register
+ * @n_bytes: how many bytes(power of 2) reqd for a given data width of client
+ * @enable_dma: Whether to enable DMA or not
+ * @read: function ptr to be used to read when doing xfer for this chip
+ * @write: function ptr to be used to write when doing xfer for this chip
+ * @xfer_type: polling/interrupt/DMA
+ *
+ * Runtime state of the SSP controller, maintained per chip,
+ * This would be set according to the current message that would be served
+ */
+struct chip_data {
+	u32 cr0;
+	u16 cr1;
+	u16 dmacr;
+	u16 cpsr;
+	u8 n_bytes;
+	bool enable_dma;
+	enum ssp_reading read;
+	enum ssp_writing write;
+	int xfer_type;
+};
+
+/**
+ * internal_cs_control - Control chip select signals via SSP_CSR.
+ * @pl022: SSP driver private data structure
+ * @command: select/delect the chip
+ *
+ * Used on controller with internal chip select control via SSP_CSR register
+ * (vendor extension). Each of the 5 LSB in the register controls one chip
+ * select signal.
+ */
+static void internal_cs_control(struct pl022 *pl022, u32 command)
+{
+	u32 tmp;
+
+	tmp = readw(SSP_CSR(pl022->virtbase));
+	if (command == SSP_CHIP_SELECT)
+		tmp &= ~BIT(pl022->cur_cs);
+	else
+		tmp |= BIT(pl022->cur_cs);
+	writew(tmp, SSP_CSR(pl022->virtbase));
+}
+
+static void pl022_cs_control(struct pl022 *pl022, u32 command)
+{
+	if (pl022->vendor->internal_cs_ctrl)
+		internal_cs_control(pl022, command);
+	else if (pl022->cur_gpiod)
+		/*
+		 * This needs to be inverted since with GPIOLIB in
+		 * control, the inversion will be handled by
+		 * GPIOLIB's active low handling. The "command"
+		 * passed into this function will be SSP_CHIP_SELECT
+		 * which is enum:ed to 0, so we need the inverse
+		 * (1) to activate chip select.
+		 */
+		gpiod_set_value(pl022->cur_gpiod, !command);
+}
+
+/**
+ * giveback - current spi_message is over, schedule next message and call
+ * callback of this message. Assumes that caller already
+ * set message->status; dma and pio irqs are blocked
+ * @pl022: SSP driver private data structure
+ */
+static void giveback(struct pl022 *pl022)
+{
+	struct spi_transfer *last_transfer;
+	pl022->next_msg_cs_active = false;
+
+	last_transfer = list_last_entry(&pl022->cur_msg->transfers,
+					struct spi_transfer, transfer_list);
+
+	/* Delay if requested before any change in chip select */
+	/*
+	 * FIXME: This runs in interrupt context.
+	 * Is this really smart?
+	 */
+	spi_transfer_delay_exec(last_transfer);
+
+	if (!last_transfer->cs_change) {
+		struct spi_message *next_msg;
+
+		/*
+		 * cs_change was not set. We can keep the chip select
+		 * enabled if there is message in the queue and it is
+		 * for the same spi device.
+		 *
+		 * We cannot postpone this until pump_messages, because
+		 * after calling msg->complete (below) the driver that
+		 * sent the current message could be unloaded, which
+		 * could invalidate the cs_control() callback...
+		 */
+		/* get a pointer to the next message, if any */
+		next_msg = spi_get_next_queued_message(pl022->master);
+
+		/*
+		 * see if the next and current messages point
+		 * to the same spi device.
+		 */
+		if (next_msg && next_msg->spi != pl022->cur_msg->spi)
+			next_msg = NULL;
+		if (!next_msg || pl022->cur_msg->state == STATE_ERROR)
+			pl022_cs_control(pl022, SSP_CHIP_DESELECT);
+		else
+			pl022->next_msg_cs_active = true;
+
+	}
+
+	pl022->cur_msg = NULL;
+	pl022->cur_transfer = NULL;
+	pl022->cur_chip = NULL;
+
+	/* disable the SPI/SSP operation */
+	writew((readw(SSP_CR1(pl022->virtbase)) &
+		(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
+
+	spi_finalize_current_message(pl022->master);
+}
+
+/**
+ * flush - flush the FIFO to reach a clean state
+ * @pl022: SSP driver private data structure
+ */
+static int flush(struct pl022 *pl022)
+{
+	unsigned long limit = loops_per_jiffy << 1;
+
+	dev_dbg(&pl022->adev->dev, "flush\n");
+	do {
+		while (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
+			readw(SSP_DR(pl022->virtbase));
+	} while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_BSY) && limit--);
+
+	pl022->exp_fifo_level = 0;
+
+	return limit;
+}
+
+/**
+ * restore_state - Load configuration of current chip
+ * @pl022: SSP driver private data structure
+ */
+static void restore_state(struct pl022 *pl022)
+{
+	struct chip_data *chip = pl022->cur_chip;
+
+	if (pl022->vendor->extended_cr)
+		writel(chip->cr0, SSP_CR0(pl022->virtbase));
+	else
+		writew(chip->cr0, SSP_CR0(pl022->virtbase));
+	writew(chip->cr1, SSP_CR1(pl022->virtbase));
+	writew(chip->dmacr, SSP_DMACR(pl022->virtbase));
+	writew(chip->cpsr, SSP_CPSR(pl022->virtbase));
+	writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
+	writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
+}
+
+/*
+ * Default SSP Register Values
+ */
+#define DEFAULT_SSP_REG_CR0 ( \
+	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS, 0)	| \
+	GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF, 4) | \
+	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
+	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
+	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
+)
+
+/* ST versions have slightly different bit layout */
+#define DEFAULT_SSP_REG_CR0_ST ( \
+	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0)	| \
+	GEN_MASK_BITS(SSP_MICROWIRE_CHANNEL_FULL_DUPLEX, SSP_CR0_MASK_HALFDUP_ST, 5) | \
+	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
+	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
+	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) | \
+	GEN_MASK_BITS(SSP_BITS_8, SSP_CR0_MASK_CSS_ST, 16)	| \
+	GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF_ST, 21) \
+)
+
+/* The PL023 version is slightly different again */
+#define DEFAULT_SSP_REG_CR0_ST_PL023 ( \
+	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0)	| \
+	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
+	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
+	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
+)
+
+#define DEFAULT_SSP_REG_CR1 ( \
+	GEN_MASK_BITS(LOOPBACK_DISABLED, SSP_CR1_MASK_LBM, 0) | \
+	GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
+	GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
+	GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) \
+)
+
+/* ST versions extend this register to use all 16 bits */
+#define DEFAULT_SSP_REG_CR1_ST ( \
+	DEFAULT_SSP_REG_CR1 | \
+	GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
+	GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
+	GEN_MASK_BITS(SSP_MWIRE_WAIT_ZERO, SSP_CR1_MASK_MWAIT_ST, 6) |\
+	GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
+	GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) \
+)
+
+/*
+ * The PL023 variant has further differences: no loopback mode, no microwire
+ * support, and a new clock feedback delay setting.
+ */
+#define DEFAULT_SSP_REG_CR1_ST_PL023 ( \
+	GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
+	GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
+	GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) | \
+	GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
+	GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
+	GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
+	GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) | \
+	GEN_MASK_BITS(SSP_FEEDBACK_CLK_DELAY_NONE, SSP_CR1_MASK_FBCLKDEL_ST, 13) \
+)
+
+#define DEFAULT_SSP_REG_CPSR ( \
+	GEN_MASK_BITS(SSP_DEFAULT_PRESCALE, SSP_CPSR_MASK_CPSDVSR, 0) \
+)
+
+#define DEFAULT_SSP_REG_DMACR (\
+	GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_RXDMAE, 0) | \
+	GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_TXDMAE, 1) \
+)
+
+/**
+ * load_ssp_default_config - Load default configuration for SSP
+ * @pl022: SSP driver private data structure
+ */
+static void load_ssp_default_config(struct pl022 *pl022)
+{
+	if (pl022->vendor->pl023) {
+		writel(DEFAULT_SSP_REG_CR0_ST_PL023, SSP_CR0(pl022->virtbase));
+		writew(DEFAULT_SSP_REG_CR1_ST_PL023, SSP_CR1(pl022->virtbase));
+	} else if (pl022->vendor->extended_cr) {
+		writel(DEFAULT_SSP_REG_CR0_ST, SSP_CR0(pl022->virtbase));
+		writew(DEFAULT_SSP_REG_CR1_ST, SSP_CR1(pl022->virtbase));
+	} else {
+		writew(DEFAULT_SSP_REG_CR0, SSP_CR0(pl022->virtbase));
+		writew(DEFAULT_SSP_REG_CR1, SSP_CR1(pl022->virtbase));
+	}
+	writew(DEFAULT_SSP_REG_DMACR, SSP_DMACR(pl022->virtbase));
+	writew(DEFAULT_SSP_REG_CPSR, SSP_CPSR(pl022->virtbase));
+	writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
+	writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
+}
+
+/*
+ * This will write to TX and read from RX according to the parameters
+ * set in pl022.
+ */
+static void readwriter(struct pl022 *pl022)
+{
+
+	/*
+	 * The FIFO depth is different between primecell variants.
+	 * I believe filling in too much in the FIFO might cause
+	 * errons in 8bit wide transfers on ARM variants (just 8 words
+	 * FIFO, means only 8x8 = 64 bits in FIFO) at least.
+	 *
+	 * To prevent this issue, the TX FIFO is only filled to the
+	 * unused RX FIFO fill length, regardless of what the TX
+	 * FIFO status flag indicates.
+	 */
+	dev_dbg(&pl022->adev->dev,
+		"%s, rx: %p, rxend: %p, tx: %p, txend: %p\n",
+		__func__, pl022->rx, pl022->rx_end, pl022->tx, pl022->tx_end);
+
+	/* Read as much as you can */
+	while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
+	       && (pl022->rx < pl022->rx_end)) {
+		switch (pl022->read) {
+		case READING_NULL:
+			readw(SSP_DR(pl022->virtbase));
+			break;
+		case READING_U8:
+			*(u8 *) (pl022->rx) =
+				readw(SSP_DR(pl022->virtbase)) & 0xFFU;
+			break;
+		case READING_U16:
+			*(u16 *) (pl022->rx) =
+				(u16) readw(SSP_DR(pl022->virtbase));
+			break;
+		case READING_U32:
+			*(u32 *) (pl022->rx) =
+				readl(SSP_DR(pl022->virtbase));
+			break;
+		}
+		pl022->rx += (pl022->cur_chip->n_bytes);
+		pl022->exp_fifo_level--;
+	}
+	/*
+	 * Write as much as possible up to the RX FIFO size
+	 */
+	while ((pl022->exp_fifo_level < pl022->vendor->fifodepth)
+	       && (pl022->tx < pl022->tx_end)) {
+		switch (pl022->write) {
+		case WRITING_NULL:
+			writew(0x0, SSP_DR(pl022->virtbase));
+			break;
+		case WRITING_U8:
+			writew(*(u8 *) (pl022->tx), SSP_DR(pl022->virtbase));
+			break;
+		case WRITING_U16:
+			writew((*(u16 *) (pl022->tx)), SSP_DR(pl022->virtbase));
+			break;
+		case WRITING_U32:
+			writel(*(u32 *) (pl022->tx), SSP_DR(pl022->virtbase));
+			break;
+		}
+		pl022->tx += (pl022->cur_chip->n_bytes);
+		pl022->exp_fifo_level++;
+		/*
+		 * This inner reader takes care of things appearing in the RX
+		 * FIFO as we're transmitting. This will happen a lot since the
+		 * clock starts running when you put things into the TX FIFO,
+		 * and then things are continuously clocked into the RX FIFO.
+		 */
+		while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
+		       && (pl022->rx < pl022->rx_end)) {
+			switch (pl022->read) {
+			case READING_NULL:
+				readw(SSP_DR(pl022->virtbase));
+				break;
+			case READING_U8:
+				*(u8 *) (pl022->rx) =
+					readw(SSP_DR(pl022->virtbase)) & 0xFFU;
+				break;
+			case READING_U16:
+				*(u16 *) (pl022->rx) =
+					(u16) readw(SSP_DR(pl022->virtbase));
+				break;
+			case READING_U32:
+				*(u32 *) (pl022->rx) =
+					readl(SSP_DR(pl022->virtbase));
+				break;
+			}
+			pl022->rx += (pl022->cur_chip->n_bytes);
+			pl022->exp_fifo_level--;
+		}
+	}
+	/*
+	 * When we exit here the TX FIFO should be full and the RX FIFO
+	 * should be empty
+	 */
+}
+
+/**
+ * next_transfer - Move to the Next transfer in the current spi message
+ * @pl022: SSP driver private data structure
+ *
+ * This function moves though the linked list of spi transfers in the
+ * current spi message and returns with the state of current spi
+ * message i.e whether its last transfer is done(STATE_DONE) or
+ * Next transfer is ready(STATE_RUNNING)
+ */
+static void *next_transfer(struct pl022 *pl022)
+{
+	struct spi_message *msg = pl022->cur_msg;
+	struct spi_transfer *trans = pl022->cur_transfer;
+
+	/* Move to next transfer */
+	if (trans->transfer_list.next != &msg->transfers) {
+		pl022->cur_transfer =
+		    list_entry(trans->transfer_list.next,
+			       struct spi_transfer, transfer_list);
+		return STATE_RUNNING;
+	}
+	return STATE_DONE;
+}
+
+/*
+ * This DMA functionality is only compiled in if we have
+ * access to the generic DMA devices/DMA engine.
+ */
+#ifdef CONFIG_DMA_ENGINE
+static void unmap_free_dma_scatter(struct pl022 *pl022)
+{
+	/* Unmap and free the SG tables */
+	dma_unmap_sg(pl022->dma_tx_channel->device->dev, pl022->sgt_tx.sgl,
+		     pl022->sgt_tx.nents, DMA_TO_DEVICE);
+	dma_unmap_sg(pl022->dma_rx_channel->device->dev, pl022->sgt_rx.sgl,
+		     pl022->sgt_rx.nents, DMA_FROM_DEVICE);
+	sg_free_table(&pl022->sgt_rx);
+	sg_free_table(&pl022->sgt_tx);
+}
+
+static void dma_callback(void *data)
+{
+	struct pl022 *pl022 = data;
+	struct spi_message *msg = pl022->cur_msg;
+
+	BUG_ON(!pl022->sgt_rx.sgl);
+
+#ifdef VERBOSE_DEBUG
+	/*
+	 * Optionally dump out buffers to inspect contents, this is
+	 * good if you want to convince yourself that the loopback
+	 * read/write contents are the same, when adopting to a new
+	 * DMA engine.
+	 */
+	{
+		struct scatterlist *sg;
+		unsigned int i;
+
+		dma_sync_sg_for_cpu(&pl022->adev->dev,
+				    pl022->sgt_rx.sgl,
+				    pl022->sgt_rx.nents,
+				    DMA_FROM_DEVICE);
+
+		for_each_sg(pl022->sgt_rx.sgl, sg, pl022->sgt_rx.nents, i) {
+			dev_dbg(&pl022->adev->dev, "SPI RX SG ENTRY: %d", i);
+			print_hex_dump(KERN_ERR, "SPI RX: ",
+				       DUMP_PREFIX_OFFSET,
+				       16,
+				       1,
+				       sg_virt(sg),
+				       sg_dma_len(sg),
+				       1);
+		}
+		for_each_sg(pl022->sgt_tx.sgl, sg, pl022->sgt_tx.nents, i) {
+			dev_dbg(&pl022->adev->dev, "SPI TX SG ENTRY: %d", i);
+			print_hex_dump(KERN_ERR, "SPI TX: ",
+				       DUMP_PREFIX_OFFSET,
+				       16,
+				       1,
+				       sg_virt(sg),
+				       sg_dma_len(sg),
+				       1);
+		}
+	}
+#endif
+
+	unmap_free_dma_scatter(pl022);
+
+	/* Update total bytes transferred */
+	msg->actual_length += pl022->cur_transfer->len;
+	/* Move to next transfer */
+	msg->state = next_transfer(pl022);
+	if (msg->state != STATE_DONE && pl022->cur_transfer->cs_change)
+		pl022_cs_control(pl022, SSP_CHIP_DESELECT);
+	tasklet_schedule(&pl022->pump_transfers);
+}
+
+static void setup_dma_scatter(struct pl022 *pl022,
+			      void *buffer,
+			      unsigned int length,
+			      struct sg_table *sgtab)
+{
+	struct scatterlist *sg;
+	int bytesleft = length;
+	void *bufp = buffer;
+	int mapbytes;
+	int i;
+
+	if (buffer) {
+		for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
+			/*
+			 * If there are less bytes left than what fits
+			 * in the current page (plus page alignment offset)
+			 * we just feed in this, else we stuff in as much
+			 * as we can.
+			 */
+			if (bytesleft < (PAGE_SIZE - offset_in_page(bufp)))
+				mapbytes = bytesleft;
+			else
+				mapbytes = PAGE_SIZE - offset_in_page(bufp);
+			sg_set_page(sg, virt_to_page(bufp),
+				    mapbytes, offset_in_page(bufp));
+			bufp += mapbytes;
+			bytesleft -= mapbytes;
+			dev_dbg(&pl022->adev->dev,
+				"set RX/TX target page @ %p, %d bytes, %d left\n",
+				bufp, mapbytes, bytesleft);
+		}
+	} else {
+		/* Map the dummy buffer on every page */
+		for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
+			if (bytesleft < PAGE_SIZE)
+				mapbytes = bytesleft;
+			else
+				mapbytes = PAGE_SIZE;
+			sg_set_page(sg, virt_to_page(pl022->dummypage),
+				    mapbytes, 0);
+			bytesleft -= mapbytes;
+			dev_dbg(&pl022->adev->dev,
+				"set RX/TX to dummy page %d bytes, %d left\n",
+				mapbytes, bytesleft);
+
+		}
+	}
+	BUG_ON(bytesleft);
+}
+
+/**
+ * configure_dma - configures the channels for the next transfer
+ * @pl022: SSP driver's private data structure
+ */
+static int configure_dma(struct pl022 *pl022)
+{
+	struct dma_slave_config rx_conf = {
+		.src_addr = SSP_DR(pl022->phybase),
+		.direction = DMA_DEV_TO_MEM,
+		.device_fc = false,
+	};
+	struct dma_slave_config tx_conf = {
+		.dst_addr = SSP_DR(pl022->phybase),
+		.direction = DMA_MEM_TO_DEV,
+		.device_fc = false,
+	};
+	unsigned int pages;
+	int ret;
+	int rx_sglen, tx_sglen;
+	struct dma_chan *rxchan = pl022->dma_rx_channel;
+	struct dma_chan *txchan = pl022->dma_tx_channel;
+	struct dma_async_tx_descriptor *rxdesc;
+	struct dma_async_tx_descriptor *txdesc;
+
+	/* Check that the channels are available */
+	if (!rxchan || !txchan)
+		return -ENODEV;
+
+	/*
+	 * If supplied, the DMA burstsize should equal the FIFO trigger level.
+	 * Notice that the DMA engine uses one-to-one mapping. Since we can
+	 * not trigger on 2 elements this needs explicit mapping rather than
+	 * calculation.
+	 */
+	switch (pl022->rx_lev_trig) {
+	case SSP_RX_1_OR_MORE_ELEM:
+		rx_conf.src_maxburst = 1;
+		break;
+	case SSP_RX_4_OR_MORE_ELEM:
+		rx_conf.src_maxburst = 4;
+		break;
+	case SSP_RX_8_OR_MORE_ELEM:
+		rx_conf.src_maxburst = 8;
+		break;
+	case SSP_RX_16_OR_MORE_ELEM:
+		rx_conf.src_maxburst = 16;
+		break;
+	case SSP_RX_32_OR_MORE_ELEM:
+		rx_conf.src_maxburst = 32;
+		break;
+	default:
+		rx_conf.src_maxburst = pl022->vendor->fifodepth >> 1;
+		break;
+	}
+
+	switch (pl022->tx_lev_trig) {
+	case SSP_TX_1_OR_MORE_EMPTY_LOC:
+		tx_conf.dst_maxburst = 1;
+		break;
+	case SSP_TX_4_OR_MORE_EMPTY_LOC:
+		tx_conf.dst_maxburst = 4;
+		break;
+	case SSP_TX_8_OR_MORE_EMPTY_LOC:
+		tx_conf.dst_maxburst = 8;
+		break;
+	case SSP_TX_16_OR_MORE_EMPTY_LOC:
+		tx_conf.dst_maxburst = 16;
+		break;
+	case SSP_TX_32_OR_MORE_EMPTY_LOC:
+		tx_conf.dst_maxburst = 32;
+		break;
+	default:
+		tx_conf.dst_maxburst = pl022->vendor->fifodepth >> 1;
+		break;
+	}
+
+	switch (pl022->read) {
+	case READING_NULL:
+		/* Use the same as for writing */
+		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
+		break;
+	case READING_U8:
+		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+		break;
+	case READING_U16:
+		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
+		break;
+	case READING_U32:
+		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+		break;
+	}
+
+	switch (pl022->write) {
+	case WRITING_NULL:
+		/* Use the same as for reading */
+		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
+		break;
+	case WRITING_U8:
+		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+		break;
+	case WRITING_U16:
+		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
+		break;
+	case WRITING_U32:
+		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+		break;
+	}
+
+	/* SPI pecularity: we need to read and write the same width */
+	if (rx_conf.src_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
+		rx_conf.src_addr_width = tx_conf.dst_addr_width;
+	if (tx_conf.dst_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
+		tx_conf.dst_addr_width = rx_conf.src_addr_width;
+	BUG_ON(rx_conf.src_addr_width != tx_conf.dst_addr_width);
+
+	dmaengine_slave_config(rxchan, &rx_conf);
+	dmaengine_slave_config(txchan, &tx_conf);
+
+	/* Create sglists for the transfers */
+	pages = DIV_ROUND_UP(pl022->cur_transfer->len, PAGE_SIZE);
+	dev_dbg(&pl022->adev->dev, "using %d pages for transfer\n", pages);
+
+	ret = sg_alloc_table(&pl022->sgt_rx, pages, GFP_ATOMIC);
+	if (ret)
+		goto err_alloc_rx_sg;
+
+	ret = sg_alloc_table(&pl022->sgt_tx, pages, GFP_ATOMIC);
+	if (ret)
+		goto err_alloc_tx_sg;
+
+	/* Fill in the scatterlists for the RX+TX buffers */
+	setup_dma_scatter(pl022, pl022->rx,
+			  pl022->cur_transfer->len, &pl022->sgt_rx);
+	setup_dma_scatter(pl022, pl022->tx,
+			  pl022->cur_transfer->len, &pl022->sgt_tx);
+
+	/* Map DMA buffers */
+	rx_sglen = dma_map_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
+			   pl022->sgt_rx.nents, DMA_FROM_DEVICE);
+	if (!rx_sglen)
+		goto err_rx_sgmap;
+
+	tx_sglen = dma_map_sg(txchan->device->dev, pl022->sgt_tx.sgl,
+			   pl022->sgt_tx.nents, DMA_TO_DEVICE);
+	if (!tx_sglen)
+		goto err_tx_sgmap;
+
+	/* Send both scatterlists */
+	rxdesc = dmaengine_prep_slave_sg(rxchan,
+				      pl022->sgt_rx.sgl,
+				      rx_sglen,
+				      DMA_DEV_TO_MEM,
+				      DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!rxdesc)
+		goto err_rxdesc;
+
+	txdesc = dmaengine_prep_slave_sg(txchan,
+				      pl022->sgt_tx.sgl,
+				      tx_sglen,
+				      DMA_MEM_TO_DEV,
+				      DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!txdesc)
+		goto err_txdesc;
+
+	/* Put the callback on the RX transfer only, that should finish last */
+	rxdesc->callback = dma_callback;
+	rxdesc->callback_param = pl022;
+
+	/* Submit and fire RX and TX with TX last so we're ready to read! */
+	dmaengine_submit(rxdesc);
+	dmaengine_submit(txdesc);
+	dma_async_issue_pending(rxchan);
+	dma_async_issue_pending(txchan);
+	pl022->dma_running = true;
+
+	return 0;
+
+err_txdesc:
+	dmaengine_terminate_all(txchan);
+err_rxdesc:
+	dmaengine_terminate_all(rxchan);
+	dma_unmap_sg(txchan->device->dev, pl022->sgt_tx.sgl,
+		     pl022->sgt_tx.nents, DMA_TO_DEVICE);
+err_tx_sgmap:
+	dma_unmap_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
+		     pl022->sgt_rx.nents, DMA_FROM_DEVICE);
+err_rx_sgmap:
+	sg_free_table(&pl022->sgt_tx);
+err_alloc_tx_sg:
+	sg_free_table(&pl022->sgt_rx);
+err_alloc_rx_sg:
+	return -ENOMEM;
+}
+
+static int pl022_dma_probe(struct pl022 *pl022)
+{
+	dma_cap_mask_t mask;
+
+	/* Try to acquire a generic DMA engine slave channel */
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+	/*
+	 * We need both RX and TX channels to do DMA, else do none
+	 * of them.
+	 */
+	pl022->dma_rx_channel = dma_request_channel(mask,
+					    pl022->master_info->dma_filter,
+					    pl022->master_info->dma_rx_param);
+	if (!pl022->dma_rx_channel) {
+		dev_dbg(&pl022->adev->dev, "no RX DMA channel!\n");
+		goto err_no_rxchan;
+	}
+
+	pl022->dma_tx_channel = dma_request_channel(mask,
+					    pl022->master_info->dma_filter,
+					    pl022->master_info->dma_tx_param);
+	if (!pl022->dma_tx_channel) {
+		dev_dbg(&pl022->adev->dev, "no TX DMA channel!\n");
+		goto err_no_txchan;
+	}
+
+	pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	if (!pl022->dummypage)
+		goto err_no_dummypage;
+
+	dev_info(&pl022->adev->dev, "setup for DMA on RX %s, TX %s\n",
+		 dma_chan_name(pl022->dma_rx_channel),
+		 dma_chan_name(pl022->dma_tx_channel));
+
+	return 0;
+
+err_no_dummypage:
+	dma_release_channel(pl022->dma_tx_channel);
+err_no_txchan:
+	dma_release_channel(pl022->dma_rx_channel);
+	pl022->dma_rx_channel = NULL;
+err_no_rxchan:
+	dev_err(&pl022->adev->dev,
+			"Failed to work in dma mode, work without dma!\n");
+	return -ENODEV;
+}
+
+static int pl022_dma_autoprobe(struct pl022 *pl022)
+{
+	struct device *dev = &pl022->adev->dev;
+	struct dma_chan *chan;
+	int err;
+
+	/* automatically configure DMA channels from platform, normally using DT */
+	chan = dma_request_chan(dev, "rx");
+	if (IS_ERR(chan)) {
+		err = PTR_ERR(chan);
+		goto err_no_rxchan;
+	}
+
+	pl022->dma_rx_channel = chan;
+
+	chan = dma_request_chan(dev, "tx");
+	if (IS_ERR(chan)) {
+		err = PTR_ERR(chan);
+		goto err_no_txchan;
+	}
+
+	pl022->dma_tx_channel = chan;
+
+	pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	if (!pl022->dummypage) {
+		err = -ENOMEM;
+		goto err_no_dummypage;
+	}
+
+	return 0;
+
+err_no_dummypage:
+	dma_release_channel(pl022->dma_tx_channel);
+	pl022->dma_tx_channel = NULL;
+err_no_txchan:
+	dma_release_channel(pl022->dma_rx_channel);
+	pl022->dma_rx_channel = NULL;
+err_no_rxchan:
+	return err;
+}
+
+static void terminate_dma(struct pl022 *pl022)
+{
+	struct dma_chan *rxchan = pl022->dma_rx_channel;
+	struct dma_chan *txchan = pl022->dma_tx_channel;
+
+	dmaengine_terminate_all(rxchan);
+	dmaengine_terminate_all(txchan);
+	unmap_free_dma_scatter(pl022);
+	pl022->dma_running = false;
+}
+
+static void pl022_dma_remove(struct pl022 *pl022)
+{
+	if (pl022->dma_running)
+		terminate_dma(pl022);
+	if (pl022->dma_tx_channel)
+		dma_release_channel(pl022->dma_tx_channel);
+	if (pl022->dma_rx_channel)
+		dma_release_channel(pl022->dma_rx_channel);
+	kfree(pl022->dummypage);
+}
+
+#else
+static inline int configure_dma(struct pl022 *pl022)
+{
+	return -ENODEV;
+}
+
+static inline int pl022_dma_autoprobe(struct pl022 *pl022)
+{
+	return 0;
+}
+
+static inline int pl022_dma_probe(struct pl022 *pl022)
+{
+	return 0;
+}
+
+static inline void pl022_dma_remove(struct pl022 *pl022)
+{
+}
+#endif
+
+/**
+ * pl022_interrupt_handler - Interrupt handler for SSP controller
+ * @irq: IRQ number
+ * @dev_id: Local device data
+ *
+ * This function handles interrupts generated for an interrupt based transfer.
+ * If a receive overrun (ROR) interrupt is there then we disable SSP, flag the
+ * current message's state as STATE_ERROR and schedule the tasklet
+ * pump_transfers which will do the postprocessing of the current message by
+ * calling giveback(). Otherwise it reads data from RX FIFO till there is no
+ * more data, and writes data in TX FIFO till it is not full. If we complete
+ * the transfer we move to the next transfer and schedule the tasklet.
+ */
+static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id)
+{
+	struct pl022 *pl022 = dev_id;
+	struct spi_message *msg = pl022->cur_msg;
+	u16 irq_status = 0;
+
+	if (unlikely(!msg)) {
+		dev_err(&pl022->adev->dev,
+			"bad message state in interrupt handler");
+		/* Never fail */
+		return IRQ_HANDLED;
+	}
+
+	/* Read the Interrupt Status Register */
+	irq_status = readw(SSP_MIS(pl022->virtbase));
+
+	if (unlikely(!irq_status))
+		return IRQ_NONE;
+
+	/*
+	 * This handles the FIFO interrupts, the timeout
+	 * interrupts are flatly ignored, they cannot be
+	 * trusted.
+	 */
+	if (unlikely(irq_status & SSP_MIS_MASK_RORMIS)) {
+		/*
+		 * Overrun interrupt - bail out since our Data has been
+		 * corrupted
+		 */
+		dev_err(&pl022->adev->dev, "FIFO overrun\n");
+		if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RFF)
+			dev_err(&pl022->adev->dev,
+				"RXFIFO is full\n");
+
+		/*
+		 * Disable and clear interrupts, disable SSP,
+		 * mark message with bad status so it can be
+		 * retried.
+		 */
+		writew(DISABLE_ALL_INTERRUPTS,
+		       SSP_IMSC(pl022->virtbase));
+		writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
+		writew((readw(SSP_CR1(pl022->virtbase)) &
+			(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
+		msg->state = STATE_ERROR;
+
+		/* Schedule message queue handler */
+		tasklet_schedule(&pl022->pump_transfers);
+		return IRQ_HANDLED;
+	}
+
+	readwriter(pl022);
+
+	if (pl022->tx == pl022->tx_end) {
+		/* Disable Transmit interrupt, enable receive interrupt */
+		writew((readw(SSP_IMSC(pl022->virtbase)) &
+		       ~SSP_IMSC_MASK_TXIM) | SSP_IMSC_MASK_RXIM,
+		       SSP_IMSC(pl022->virtbase));
+	}
+
+	/*
+	 * Since all transactions must write as much as shall be read,
+	 * we can conclude the entire transaction once RX is complete.
+	 * At this point, all TX will always be finished.
+	 */
+	if (pl022->rx >= pl022->rx_end) {
+		writew(DISABLE_ALL_INTERRUPTS,
+		       SSP_IMSC(pl022->virtbase));
+		writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
+		if (unlikely(pl022->rx > pl022->rx_end)) {
+			dev_warn(&pl022->adev->dev, "read %u surplus "
+				 "bytes (did you request an odd "
+				 "number of bytes on a 16bit bus?)\n",
+				 (u32) (pl022->rx - pl022->rx_end));
+		}
+		/* Update total bytes transferred */
+		msg->actual_length += pl022->cur_transfer->len;
+		/* Move to next transfer */
+		msg->state = next_transfer(pl022);
+		if (msg->state != STATE_DONE && pl022->cur_transfer->cs_change)
+			pl022_cs_control(pl022, SSP_CHIP_DESELECT);
+		tasklet_schedule(&pl022->pump_transfers);
+		return IRQ_HANDLED;
+	}
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * This sets up the pointers to memory for the next message to
+ * send out on the SPI bus.
+ */
+static int set_up_next_transfer(struct pl022 *pl022,
+				struct spi_transfer *transfer)
+{
+	int residue;
+
+	/* Sanity check the message for this bus width */
+	residue = pl022->cur_transfer->len % pl022->cur_chip->n_bytes;
+	if (unlikely(residue != 0)) {
+		dev_err(&pl022->adev->dev,
+			"message of %u bytes to transmit but the current "
+			"chip bus has a data width of %u bytes!\n",
+			pl022->cur_transfer->len,
+			pl022->cur_chip->n_bytes);
+		dev_err(&pl022->adev->dev, "skipping this message\n");
+		return -EIO;
+	}
+	pl022->tx = (void *)transfer->tx_buf;
+	pl022->tx_end = pl022->tx + pl022->cur_transfer->len;
+	pl022->rx = (void *)transfer->rx_buf;
+	pl022->rx_end = pl022->rx + pl022->cur_transfer->len;
+	pl022->write =
+	    pl022->tx ? pl022->cur_chip->write : WRITING_NULL;
+	pl022->read = pl022->rx ? pl022->cur_chip->read : READING_NULL;
+	return 0;
+}
+
+/**
+ * pump_transfers - Tasklet function which schedules next transfer
+ * when running in interrupt or DMA transfer mode.
+ * @data: SSP driver private data structure
+ *
+ */
+static void pump_transfers(unsigned long data)
+{
+	struct pl022 *pl022 = (struct pl022 *) data;
+	struct spi_message *message = NULL;
+	struct spi_transfer *transfer = NULL;
+	struct spi_transfer *previous = NULL;
+
+	/* Get current state information */
+	message = pl022->cur_msg;
+	transfer = pl022->cur_transfer;
+
+	/* Handle for abort */
+	if (message->state == STATE_ERROR) {
+		message->status = -EIO;
+		giveback(pl022);
+		return;
+	}
+
+	/* Handle end of message */
+	if (message->state == STATE_DONE) {
+		message->status = 0;
+		giveback(pl022);
+		return;
+	}
+
+	/* Delay if requested at end of transfer before CS change */
+	if (message->state == STATE_RUNNING) {
+		previous = list_entry(transfer->transfer_list.prev,
+					struct spi_transfer,
+					transfer_list);
+		/*
+		 * FIXME: This runs in interrupt context.
+		 * Is this really smart?
+		 */
+		spi_transfer_delay_exec(previous);
+
+		/* Reselect chip select only if cs_change was requested */
+		if (previous->cs_change)
+			pl022_cs_control(pl022, SSP_CHIP_SELECT);
+	} else {
+		/* STATE_START */
+		message->state = STATE_RUNNING;
+	}
+
+	if (set_up_next_transfer(pl022, transfer)) {
+		message->state = STATE_ERROR;
+		message->status = -EIO;
+		giveback(pl022);
+		return;
+	}
+	/* Flush the FIFOs and let's go! */
+	flush(pl022);
+
+	if (pl022->cur_chip->enable_dma) {
+		if (configure_dma(pl022)) {
+			dev_dbg(&pl022->adev->dev,
+				"configuration of DMA failed, fall back to interrupt mode\n");
+			goto err_config_dma;
+		}
+		return;
+	}
+
+err_config_dma:
+	/* enable all interrupts except RX */
+	writew(ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM, SSP_IMSC(pl022->virtbase));
+}
+
+static void do_interrupt_dma_transfer(struct pl022 *pl022)
+{
+	/*
+	 * Default is to enable all interrupts except RX -
+	 * this will be enabled once TX is complete
+	 */
+	u32 irqflags = (u32)(ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM);
+
+	/* Enable target chip, if not already active */
+	if (!pl022->next_msg_cs_active)
+		pl022_cs_control(pl022, SSP_CHIP_SELECT);
+
+	if (set_up_next_transfer(pl022, pl022->cur_transfer)) {
+		/* Error path */
+		pl022->cur_msg->state = STATE_ERROR;
+		pl022->cur_msg->status = -EIO;
+		giveback(pl022);
+		return;
+	}
+	/* If we're using DMA, set up DMA here */
+	if (pl022->cur_chip->enable_dma) {
+		/* Configure DMA transfer */
+		if (configure_dma(pl022)) {
+			dev_dbg(&pl022->adev->dev,
+				"configuration of DMA failed, fall back to interrupt mode\n");
+			goto err_config_dma;
+		}
+		/* Disable interrupts in DMA mode, IRQ from DMA controller */
+		irqflags = DISABLE_ALL_INTERRUPTS;
+	}
+err_config_dma:
+	/* Enable SSP, turn on interrupts */
+	writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
+	       SSP_CR1(pl022->virtbase));
+	writew(irqflags, SSP_IMSC(pl022->virtbase));
+}
+
+static void print_current_status(struct pl022 *pl022)
+{
+	u32 read_cr0;
+	u16 read_cr1, read_dmacr, read_sr;
+
+	if (pl022->vendor->extended_cr)
+		read_cr0 = readl(SSP_CR0(pl022->virtbase));
+	else
+		read_cr0 = readw(SSP_CR0(pl022->virtbase));
+	read_cr1 = readw(SSP_CR1(pl022->virtbase));
+	read_dmacr = readw(SSP_DMACR(pl022->virtbase));
+	read_sr = readw(SSP_SR(pl022->virtbase));
+
+	dev_warn(&pl022->adev->dev, "spi-pl022 CR0: %x\n", read_cr0);
+	dev_warn(&pl022->adev->dev, "spi-pl022 CR1: %x\n", read_cr1);
+	dev_warn(&pl022->adev->dev, "spi-pl022 DMACR: %x\n", read_dmacr);
+	dev_warn(&pl022->adev->dev, "spi-pl022 SR: %x\n", read_sr);
+	dev_warn(&pl022->adev->dev,
+			"spi-pl022 exp_fifo_level/fifodepth: %u/%d\n",
+			pl022->exp_fifo_level,
+			pl022->vendor->fifodepth);
+
+}
+
+static void do_polling_transfer(struct pl022 *pl022)
+{
+	struct spi_message *message = NULL;
+	struct spi_transfer *transfer = NULL;
+	struct spi_transfer *previous = NULL;
+	unsigned long time, timeout;
+
+	message = pl022->cur_msg;
+
+	while (message->state != STATE_DONE) {
+		/* Handle for abort */
+		if (message->state == STATE_ERROR)
+			break;
+		transfer = pl022->cur_transfer;
+
+		/* Delay if requested at end of transfer */
+		if (message->state == STATE_RUNNING) {
+			previous =
+			    list_entry(transfer->transfer_list.prev,
+				       struct spi_transfer, transfer_list);
+			spi_transfer_delay_exec(previous);
+			if (previous->cs_change)
+				pl022_cs_control(pl022, SSP_CHIP_SELECT);
+		} else {
+			/* STATE_START */
+			message->state = STATE_RUNNING;
+			if (!pl022->next_msg_cs_active)
+				pl022_cs_control(pl022, SSP_CHIP_SELECT);
+		}
+
+		/* Configuration Changing Per Transfer */
+		if (set_up_next_transfer(pl022, transfer)) {
+			/* Error path */
+			message->state = STATE_ERROR;
+			break;
+		}
+		/* Flush FIFOs and enable SSP */
+		flush(pl022);
+		writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
+		       SSP_CR1(pl022->virtbase));
+
+		dev_dbg(&pl022->adev->dev, "polling transfer ongoing ...\n");
+
+		timeout = jiffies + msecs_to_jiffies(SPI_POLLING_TIMEOUT);
+		while (pl022->tx < pl022->tx_end || pl022->rx < pl022->rx_end) {
+			time = jiffies;
+			readwriter(pl022);
+			if (time_after(time, timeout)) {
+				dev_warn(&pl022->adev->dev,
+				"%s: timeout!\n", __func__);
+				message->state = STATE_TIMEOUT;
+				print_current_status(pl022);
+				goto out;
+			}
+			cpu_relax();
+		}
+
+		/* Update total byte transferred */
+		message->actual_length += pl022->cur_transfer->len;
+		/* Move to next transfer */
+		message->state = next_transfer(pl022);
+		if (message->state != STATE_DONE
+		    && pl022->cur_transfer->cs_change)
+			pl022_cs_control(pl022, SSP_CHIP_DESELECT);
+	}
+out:
+	/* Handle end of message */
+	if (message->state == STATE_DONE)
+		message->status = 0;
+	else if (message->state == STATE_TIMEOUT)
+		message->status = -EAGAIN;
+	else
+		message->status = -EIO;
+
+	giveback(pl022);
+	return;
+}
+
+static int pl022_transfer_one_message(struct spi_master *master,
+				      struct spi_message *msg)
+{
+	struct pl022 *pl022 = spi_master_get_devdata(master);
+
+	/* Initial message state */
+	pl022->cur_msg = msg;
+	msg->state = STATE_START;
+
+	pl022->cur_transfer = list_entry(msg->transfers.next,
+					 struct spi_transfer, transfer_list);
+
+	/* Setup the SPI using the per chip configuration */
+	pl022->cur_chip = spi_get_ctldata(msg->spi);
+	pl022->cur_cs = msg->spi->chip_select;
+	/* This is always available but may be set to -ENOENT */
+	pl022->cur_gpiod = msg->spi->cs_gpiod;
+
+	restore_state(pl022);
+	flush(pl022);
+
+	if (pl022->cur_chip->xfer_type == POLLING_TRANSFER)
+		do_polling_transfer(pl022);
+	else
+		do_interrupt_dma_transfer(pl022);
+
+	return 0;
+}
+
+static int pl022_unprepare_transfer_hardware(struct spi_master *master)
+{
+	struct pl022 *pl022 = spi_master_get_devdata(master);
+
+	/* nothing more to do - disable spi/ssp and power off */
+	writew((readw(SSP_CR1(pl022->virtbase)) &
+		(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
+
+	return 0;
+}
+
+static int verify_controller_parameters(struct pl022 *pl022,
+				struct pl022_config_chip const *chip_info)
+{
+	if ((chip_info->iface < SSP_INTERFACE_MOTOROLA_SPI)
+	    || (chip_info->iface > SSP_INTERFACE_UNIDIRECTIONAL)) {
+		dev_err(&pl022->adev->dev,
+			"interface is configured incorrectly\n");
+		return -EINVAL;
+	}
+	if ((chip_info->iface == SSP_INTERFACE_UNIDIRECTIONAL) &&
+	    (!pl022->vendor->unidir)) {
+		dev_err(&pl022->adev->dev,
+			"unidirectional mode not supported in this "
+			"hardware version\n");
+		return -EINVAL;
+	}
+	if ((chip_info->hierarchy != SSP_MASTER)
+	    && (chip_info->hierarchy != SSP_SLAVE)) {
+		dev_err(&pl022->adev->dev,
+			"hierarchy is configured incorrectly\n");
+		return -EINVAL;
+	}
+	if ((chip_info->com_mode != INTERRUPT_TRANSFER)
+	    && (chip_info->com_mode != DMA_TRANSFER)
+	    && (chip_info->com_mode != POLLING_TRANSFER)) {
+		dev_err(&pl022->adev->dev,
+			"Communication mode is configured incorrectly\n");
+		return -EINVAL;
+	}
+	switch (chip_info->rx_lev_trig) {
+	case SSP_RX_1_OR_MORE_ELEM:
+	case SSP_RX_4_OR_MORE_ELEM:
+	case SSP_RX_8_OR_MORE_ELEM:
+		/* These are always OK, all variants can handle this */
+		break;
+	case SSP_RX_16_OR_MORE_ELEM:
+		if (pl022->vendor->fifodepth < 16) {
+			dev_err(&pl022->adev->dev,
+			"RX FIFO Trigger Level is configured incorrectly\n");
+			return -EINVAL;
+		}
+		break;
+	case SSP_RX_32_OR_MORE_ELEM:
+		if (pl022->vendor->fifodepth < 32) {
+			dev_err(&pl022->adev->dev,
+			"RX FIFO Trigger Level is configured incorrectly\n");
+			return -EINVAL;
+		}
+		break;
+	default:
+		dev_err(&pl022->adev->dev,
+			"RX FIFO Trigger Level is configured incorrectly\n");
+		return -EINVAL;
+	}
+	switch (chip_info->tx_lev_trig) {
+	case SSP_TX_1_OR_MORE_EMPTY_LOC:
+	case SSP_TX_4_OR_MORE_EMPTY_LOC:
+	case SSP_TX_8_OR_MORE_EMPTY_LOC:
+		/* These are always OK, all variants can handle this */
+		break;
+	case SSP_TX_16_OR_MORE_EMPTY_LOC:
+		if (pl022->vendor->fifodepth < 16) {
+			dev_err(&pl022->adev->dev,
+			"TX FIFO Trigger Level is configured incorrectly\n");
+			return -EINVAL;
+		}
+		break;
+	case SSP_TX_32_OR_MORE_EMPTY_LOC:
+		if (pl022->vendor->fifodepth < 32) {
+			dev_err(&pl022->adev->dev,
+			"TX FIFO Trigger Level is configured incorrectly\n");
+			return -EINVAL;
+		}
+		break;
+	default:
+		dev_err(&pl022->adev->dev,
+			"TX FIFO Trigger Level is configured incorrectly\n");
+		return -EINVAL;
+	}
+	if (chip_info->iface == SSP_INTERFACE_NATIONAL_MICROWIRE) {
+		if ((chip_info->ctrl_len < SSP_BITS_4)
+		    || (chip_info->ctrl_len > SSP_BITS_32)) {
+			dev_err(&pl022->adev->dev,
+				"CTRL LEN is configured incorrectly\n");
+			return -EINVAL;
+		}
+		if ((chip_info->wait_state != SSP_MWIRE_WAIT_ZERO)
+		    && (chip_info->wait_state != SSP_MWIRE_WAIT_ONE)) {
+			dev_err(&pl022->adev->dev,
+				"Wait State is configured incorrectly\n");
+			return -EINVAL;
+		}
+		/* Half duplex is only available in the ST Micro version */
+		if (pl022->vendor->extended_cr) {
+			if ((chip_info->duplex !=
+			     SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
+			    && (chip_info->duplex !=
+				SSP_MICROWIRE_CHANNEL_HALF_DUPLEX)) {
+				dev_err(&pl022->adev->dev,
+					"Microwire duplex mode is configured incorrectly\n");
+				return -EINVAL;
+			}
+		} else {
+			if (chip_info->duplex != SSP_MICROWIRE_CHANNEL_FULL_DUPLEX) {
+				dev_err(&pl022->adev->dev,
+					"Microwire half duplex mode requested,"
+					" but this is only available in the"
+					" ST version of PL022\n");
+				return -EINVAL;
+			}
+		}
+	}
+	return 0;
+}
+
+static inline u32 spi_rate(u32 rate, u16 cpsdvsr, u16 scr)
+{
+	return rate / (cpsdvsr * (1 + scr));
+}
+
+static int calculate_effective_freq(struct pl022 *pl022, int freq, struct
+				    ssp_clock_params * clk_freq)
+{
+	/* Lets calculate the frequency parameters */
+	u16 cpsdvsr = CPSDVR_MIN, scr = SCR_MIN;
+	u32 rate, max_tclk, min_tclk, best_freq = 0, best_cpsdvsr = 0,
+		best_scr = 0, tmp, found = 0;
+
+	rate = clk_get_rate(pl022->clk);
+	/* cpsdvscr = 2 & scr 0 */
+	max_tclk = spi_rate(rate, CPSDVR_MIN, SCR_MIN);
+	/* cpsdvsr = 254 & scr = 255 */
+	min_tclk = spi_rate(rate, CPSDVR_MAX, SCR_MAX);
+
+	if (freq > max_tclk)
+		dev_warn(&pl022->adev->dev,
+			"Max speed that can be programmed is %d Hz, you requested %d\n",
+			max_tclk, freq);
+
+	if (freq < min_tclk) {
+		dev_err(&pl022->adev->dev,
+			"Requested frequency: %d Hz is less than minimum possible %d Hz\n",
+			freq, min_tclk);
+		return -EINVAL;
+	}
+
+	/*
+	 * best_freq will give closest possible available rate (<= requested
+	 * freq) for all values of scr & cpsdvsr.
+	 */
+	while ((cpsdvsr <= CPSDVR_MAX) && !found) {
+		while (scr <= SCR_MAX) {
+			tmp = spi_rate(rate, cpsdvsr, scr);
+
+			if (tmp > freq) {
+				/* we need lower freq */
+				scr++;
+				continue;
+			}
+
+			/*
+			 * If found exact value, mark found and break.
+			 * If found more closer value, update and break.
+			 */
+			if (tmp > best_freq) {
+				best_freq = tmp;
+				best_cpsdvsr = cpsdvsr;
+				best_scr = scr;
+
+				if (tmp == freq)
+					found = 1;
+			}
+			/*
+			 * increased scr will give lower rates, which are not
+			 * required
+			 */
+			break;
+		}
+		cpsdvsr += 2;
+		scr = SCR_MIN;
+	}
+
+	WARN(!best_freq, "pl022: Matching cpsdvsr and scr not found for %d Hz rate \n",
+			freq);
+
+	clk_freq->cpsdvsr = (u8) (best_cpsdvsr & 0xFF);
+	clk_freq->scr = (u8) (best_scr & 0xFF);
+	dev_dbg(&pl022->adev->dev,
+		"SSP Target Frequency is: %u, Effective Frequency is %u\n",
+		freq, best_freq);
+	dev_dbg(&pl022->adev->dev, "SSP cpsdvsr = %d, scr = %d\n",
+		clk_freq->cpsdvsr, clk_freq->scr);
+
+	return 0;
+}
+
+/*
+ * A piece of default chip info unless the platform
+ * supplies it.
+ */
+static const struct pl022_config_chip pl022_default_chip_info = {
+	.com_mode = INTERRUPT_TRANSFER,
+	.iface = SSP_INTERFACE_MOTOROLA_SPI,
+	.hierarchy = SSP_MASTER,
+	.slave_tx_disable = DO_NOT_DRIVE_TX,
+	.rx_lev_trig = SSP_RX_1_OR_MORE_ELEM,
+	.tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC,
+	.ctrl_len = SSP_BITS_8,
+	.wait_state = SSP_MWIRE_WAIT_ZERO,
+	.duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX,
+};
+
+/**
+ * pl022_setup - setup function registered to SPI master framework
+ * @spi: spi device which is requesting setup
+ *
+ * This function is registered to the SPI framework for this SPI master
+ * controller. If it is the first time when setup is called by this device,
+ * this function will initialize the runtime state for this chip and save
+ * the same in the device structure. Else it will update the runtime info
+ * with the updated chip info. Nothing is really being written to the
+ * controller hardware here, that is not done until the actual transfer
+ * commence.
+ */
+static int pl022_setup(struct spi_device *spi)
+{
+	struct pl022_config_chip const *chip_info;
+	struct pl022_config_chip chip_info_dt;
+	struct chip_data *chip;
+	struct ssp_clock_params clk_freq = { .cpsdvsr = 0, .scr = 0};
+	int status = 0;
+	struct pl022 *pl022 = spi_master_get_devdata(spi->master);
+	unsigned int bits = spi->bits_per_word;
+	u32 tmp;
+	struct device_node *np = spi->dev.of_node;
+
+	if (!spi->max_speed_hz)
+		return -EINVAL;
+
+	/* Get controller_state if one is supplied */
+	chip = spi_get_ctldata(spi);
+
+	if (chip == NULL) {
+		chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
+		if (!chip)
+			return -ENOMEM;
+		dev_dbg(&spi->dev,
+			"allocated memory for controller's runtime state\n");
+	}
+
+	/* Get controller data if one is supplied */
+	chip_info = spi->controller_data;
+
+	if (chip_info == NULL) {
+		if (np) {
+			chip_info_dt = pl022_default_chip_info;
+
+			chip_info_dt.hierarchy = SSP_MASTER;
+			of_property_read_u32(np, "pl022,interface",
+				&chip_info_dt.iface);
+			of_property_read_u32(np, "pl022,com-mode",
+				&chip_info_dt.com_mode);
+			of_property_read_u32(np, "pl022,rx-level-trig",
+				&chip_info_dt.rx_lev_trig);
+			of_property_read_u32(np, "pl022,tx-level-trig",
+				&chip_info_dt.tx_lev_trig);
+			of_property_read_u32(np, "pl022,ctrl-len",
+				&chip_info_dt.ctrl_len);
+			of_property_read_u32(np, "pl022,wait-state",
+				&chip_info_dt.wait_state);
+			of_property_read_u32(np, "pl022,duplex",
+				&chip_info_dt.duplex);
+
+			chip_info = &chip_info_dt;
+		} else {
+			chip_info = &pl022_default_chip_info;
+			/* spi_board_info.controller_data not is supplied */
+			dev_dbg(&spi->dev,
+				"using default controller_data settings\n");
+		}
+	} else
+		dev_dbg(&spi->dev,
+			"using user supplied controller_data settings\n");
+
+	/*
+	 * We can override with custom divisors, else we use the board
+	 * frequency setting
+	 */
+	if ((0 == chip_info->clk_freq.cpsdvsr)
+	    && (0 == chip_info->clk_freq.scr)) {
+		status = calculate_effective_freq(pl022,
+						  spi->max_speed_hz,
+						  &clk_freq);
+		if (status < 0)
+			goto err_config_params;
+	} else {
+		memcpy(&clk_freq, &chip_info->clk_freq, sizeof(clk_freq));
+		if ((clk_freq.cpsdvsr % 2) != 0)
+			clk_freq.cpsdvsr =
+				clk_freq.cpsdvsr - 1;
+	}
+	if ((clk_freq.cpsdvsr < CPSDVR_MIN)
+	    || (clk_freq.cpsdvsr > CPSDVR_MAX)) {
+		status = -EINVAL;
+		dev_err(&spi->dev,
+			"cpsdvsr is configured incorrectly\n");
+		goto err_config_params;
+	}
+
+	status = verify_controller_parameters(pl022, chip_info);
+	if (status) {
+		dev_err(&spi->dev, "controller data is incorrect");
+		goto err_config_params;
+	}
+
+	pl022->rx_lev_trig = chip_info->rx_lev_trig;
+	pl022->tx_lev_trig = chip_info->tx_lev_trig;
+
+	/* Now set controller state based on controller data */
+	chip->xfer_type = chip_info->com_mode;
+
+	/* Check bits per word with vendor specific range */
+	if ((bits <= 3) || (bits > pl022->vendor->max_bpw)) {
+		status = -ENOTSUPP;
+		dev_err(&spi->dev, "illegal data size for this controller!\n");
+		dev_err(&spi->dev, "This controller can only handle 4 <= n <= %d bit words\n",
+				pl022->vendor->max_bpw);
+		goto err_config_params;
+	} else if (bits <= 8) {
+		dev_dbg(&spi->dev, "4 <= n <=8 bits per word\n");
+		chip->n_bytes = 1;
+		chip->read = READING_U8;
+		chip->write = WRITING_U8;
+	} else if (bits <= 16) {
+		dev_dbg(&spi->dev, "9 <= n <= 16 bits per word\n");
+		chip->n_bytes = 2;
+		chip->read = READING_U16;
+		chip->write = WRITING_U16;
+	} else {
+		dev_dbg(&spi->dev, "17 <= n <= 32 bits per word\n");
+		chip->n_bytes = 4;
+		chip->read = READING_U32;
+		chip->write = WRITING_U32;
+	}
+
+	/* Now Initialize all register settings required for this chip */
+	chip->cr0 = 0;
+	chip->cr1 = 0;
+	chip->dmacr = 0;
+	chip->cpsr = 0;
+	if ((chip_info->com_mode == DMA_TRANSFER)
+	    && ((pl022->master_info)->enable_dma)) {
+		chip->enable_dma = true;
+		dev_dbg(&spi->dev, "DMA mode set in controller state\n");
+		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
+			       SSP_DMACR_MASK_RXDMAE, 0);
+		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
+			       SSP_DMACR_MASK_TXDMAE, 1);
+	} else {
+		chip->enable_dma = false;
+		dev_dbg(&spi->dev, "DMA mode NOT set in controller state\n");
+		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
+			       SSP_DMACR_MASK_RXDMAE, 0);
+		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
+			       SSP_DMACR_MASK_TXDMAE, 1);
+	}
+
+	chip->cpsr = clk_freq.cpsdvsr;
+
+	/* Special setup for the ST micro extended control registers */
+	if (pl022->vendor->extended_cr) {
+		u32 etx;
+
+		if (pl022->vendor->pl023) {
+			/* These bits are only in the PL023 */
+			SSP_WRITE_BITS(chip->cr1, chip_info->clkdelay,
+				       SSP_CR1_MASK_FBCLKDEL_ST, 13);
+		} else {
+			/* These bits are in the PL022 but not PL023 */
+			SSP_WRITE_BITS(chip->cr0, chip_info->duplex,
+				       SSP_CR0_MASK_HALFDUP_ST, 5);
+			SSP_WRITE_BITS(chip->cr0, chip_info->ctrl_len,
+				       SSP_CR0_MASK_CSS_ST, 16);
+			SSP_WRITE_BITS(chip->cr0, chip_info->iface,
+				       SSP_CR0_MASK_FRF_ST, 21);
+			SSP_WRITE_BITS(chip->cr1, chip_info->wait_state,
+				       SSP_CR1_MASK_MWAIT_ST, 6);
+		}
+		SSP_WRITE_BITS(chip->cr0, bits - 1,
+			       SSP_CR0_MASK_DSS_ST, 0);
+
+		if (spi->mode & SPI_LSB_FIRST) {
+			tmp = SSP_RX_LSB;
+			etx = SSP_TX_LSB;
+		} else {
+			tmp = SSP_RX_MSB;
+			etx = SSP_TX_MSB;
+		}
+		SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_RENDN_ST, 4);
+		SSP_WRITE_BITS(chip->cr1, etx, SSP_CR1_MASK_TENDN_ST, 5);
+		SSP_WRITE_BITS(chip->cr1, chip_info->rx_lev_trig,
+			       SSP_CR1_MASK_RXIFLSEL_ST, 7);
+		SSP_WRITE_BITS(chip->cr1, chip_info->tx_lev_trig,
+			       SSP_CR1_MASK_TXIFLSEL_ST, 10);
+	} else {
+		SSP_WRITE_BITS(chip->cr0, bits - 1,
+			       SSP_CR0_MASK_DSS, 0);
+		SSP_WRITE_BITS(chip->cr0, chip_info->iface,
+			       SSP_CR0_MASK_FRF, 4);
+	}
+
+	/* Stuff that is common for all versions */
+	if (spi->mode & SPI_CPOL)
+		tmp = SSP_CLK_POL_IDLE_HIGH;
+	else
+		tmp = SSP_CLK_POL_IDLE_LOW;
+	SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPO, 6);
+
+	if (spi->mode & SPI_CPHA)
+		tmp = SSP_CLK_SECOND_EDGE;
+	else
+		tmp = SSP_CLK_FIRST_EDGE;
+	SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPH, 7);
+
+	SSP_WRITE_BITS(chip->cr0, clk_freq.scr, SSP_CR0_MASK_SCR, 8);
+	/* Loopback is available on all versions except PL023 */
+	if (pl022->vendor->loopback) {
+		if (spi->mode & SPI_LOOP)
+			tmp = LOOPBACK_ENABLED;
+		else
+			tmp = LOOPBACK_DISABLED;
+		SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_LBM, 0);
+	}
+	SSP_WRITE_BITS(chip->cr1, SSP_DISABLED, SSP_CR1_MASK_SSE, 1);
+	SSP_WRITE_BITS(chip->cr1, chip_info->hierarchy, SSP_CR1_MASK_MS, 2);
+	SSP_WRITE_BITS(chip->cr1, chip_info->slave_tx_disable, SSP_CR1_MASK_SOD,
+		3);
+
+	/* Save controller_state */
+	spi_set_ctldata(spi, chip);
+	return status;
+ err_config_params:
+	spi_set_ctldata(spi, NULL);
+	kfree(chip);
+	return status;
+}
+
+/**
+ * pl022_cleanup - cleanup function registered to SPI master framework
+ * @spi: spi device which is requesting cleanup
+ *
+ * This function is registered to the SPI framework for this SPI master
+ * controller. It will free the runtime state of chip.
+ */
+static void pl022_cleanup(struct spi_device *spi)
+{
+	struct chip_data *chip = spi_get_ctldata(spi);
+
+	spi_set_ctldata(spi, NULL);
+	kfree(chip);
+}
+
+static struct pl022_ssp_controller *
+pl022_platform_data_dt_get(struct device *dev)
+{
+	struct device_node *np = dev->of_node;
+	struct pl022_ssp_controller *pd;
+
+	if (!np) {
+		dev_err(dev, "no dt node defined\n");
+		return NULL;
+	}
+
+	pd = devm_kzalloc(dev, sizeof(struct pl022_ssp_controller), GFP_KERNEL);
+	if (!pd)
+		return NULL;
+
+	pd->bus_id = -1;
+	pd->enable_dma = 1;
+	of_property_read_u32(np, "pl022,autosuspend-delay",
+			     &pd->autosuspend_delay);
+	pd->rt = of_property_read_bool(np, "pl022,rt");
+
+	return pd;
+}
+
+static int pl022_probe(struct amba_device *adev, const struct amba_id *id)
+{
+	struct device *dev = &adev->dev;
+	struct pl022_ssp_controller *platform_info =
+			dev_get_platdata(&adev->dev);
+	struct spi_master *master;
+	struct pl022 *pl022 = NULL;	/*Data for this driver */
+	int status = 0;
+
+	dev_info(&adev->dev,
+		 "ARM PL022 driver, device ID: 0x%08x\n", adev->periphid);
+	if (!platform_info && IS_ENABLED(CONFIG_OF))
+		platform_info = pl022_platform_data_dt_get(dev);
+
+	if (!platform_info) {
+		dev_err(dev, "probe: no platform data defined\n");
+		return -ENODEV;
+	}
+
+	/* Allocate master with space for data */
+	master = spi_alloc_master(dev, sizeof(struct pl022));
+	if (master == NULL) {
+		dev_err(&adev->dev, "probe - cannot alloc SPI master\n");
+		return -ENOMEM;
+	}
+
+	pl022 = spi_master_get_devdata(master);
+	pl022->master = master;
+	pl022->master_info = platform_info;
+	pl022->adev = adev;
+	pl022->vendor = id->data;
+
+	/*
+	 * Bus Number Which has been Assigned to this SSP controller
+	 * on this board
+	 */
+	master->bus_num = platform_info->bus_id;
+	master->cleanup = pl022_cleanup;
+	master->setup = pl022_setup;
+	master->auto_runtime_pm = true;
+	master->transfer_one_message = pl022_transfer_one_message;
+	master->unprepare_transfer_hardware = pl022_unprepare_transfer_hardware;
+	master->rt = platform_info->rt;
+	master->dev.of_node = dev->of_node;
+	master->use_gpio_descriptors = true;
+
+	/*
+	 * Supports mode 0-3, loopback, and active low CS. Transfers are
+	 * always MS bit first on the original pl022.
+	 */
+	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LOOP;
+	if (pl022->vendor->extended_cr)
+		master->mode_bits |= SPI_LSB_FIRST;
+
+	dev_dbg(&adev->dev, "BUSNO: %d\n", master->bus_num);
+
+	status = amba_request_regions(adev, NULL);
+	if (status)
+		goto err_no_ioregion;
+
+	pl022->phybase = adev->res.start;
+	pl022->virtbase = devm_ioremap(dev, adev->res.start,
+				       resource_size(&adev->res));
+	if (pl022->virtbase == NULL) {
+		status = -ENOMEM;
+		goto err_no_ioremap;
+	}
+	dev_info(&adev->dev, "mapped registers from %pa to %p\n",
+		&adev->res.start, pl022->virtbase);
+
+	pl022->clk = devm_clk_get(&adev->dev, NULL);
+	if (IS_ERR(pl022->clk)) {
+		status = PTR_ERR(pl022->clk);
+		dev_err(&adev->dev, "could not retrieve SSP/SPI bus clock\n");
+		goto err_no_clk;
+	}
+
+	status = clk_prepare_enable(pl022->clk);
+	if (status) {
+		dev_err(&adev->dev, "could not enable SSP/SPI bus clock\n");
+		goto err_no_clk_en;
+	}
+
+	/* Initialize transfer pump */
+	tasklet_init(&pl022->pump_transfers, pump_transfers,
+		     (unsigned long)pl022);
+
+	/* Disable SSP */
+	writew((readw(SSP_CR1(pl022->virtbase)) & (~SSP_CR1_MASK_SSE)),
+	       SSP_CR1(pl022->virtbase));
+	load_ssp_default_config(pl022);
+
+	status = devm_request_irq(dev, adev->irq[0], pl022_interrupt_handler,
+				  0, "pl022", pl022);
+	if (status < 0) {
+		dev_err(&adev->dev, "probe - cannot get IRQ (%d)\n", status);
+		goto err_no_irq;
+	}
+
+	/* Get DMA channels, try autoconfiguration first */
+	status = pl022_dma_autoprobe(pl022);
+	if (status == -EPROBE_DEFER) {
+		dev_dbg(dev, "deferring probe to get DMA channel\n");
+		goto err_no_irq;
+	}
+
+	/* If that failed, use channels from platform_info */
+	if (status == 0)
+		platform_info->enable_dma = 1;
+	else if (platform_info->enable_dma) {
+		status = pl022_dma_probe(pl022);
+		if (status != 0)
+			platform_info->enable_dma = 0;
+	}
+
+	/* Register with the SPI framework */
+	amba_set_drvdata(adev, pl022);
+	status = devm_spi_register_master(&adev->dev, master);
+	if (status != 0) {
+		dev_err(&adev->dev,
+			"probe - problem registering spi master\n");
+		goto err_spi_register;
+	}
+	dev_dbg(dev, "probe succeeded\n");
+
+	/* let runtime pm put suspend */
+	if (platform_info->autosuspend_delay > 0) {
+		dev_info(&adev->dev,
+			"will use autosuspend for runtime pm, delay %dms\n",
+			platform_info->autosuspend_delay);
+		pm_runtime_set_autosuspend_delay(dev,
+			platform_info->autosuspend_delay);
+		pm_runtime_use_autosuspend(dev);
+	}
+	pm_runtime_put(dev);
+
+	return 0;
+
+ err_spi_register:
+	if (platform_info->enable_dma)
+		pl022_dma_remove(pl022);
+ err_no_irq:
+	clk_disable_unprepare(pl022->clk);
+ err_no_clk_en:
+ err_no_clk:
+ err_no_ioremap:
+	amba_release_regions(adev);
+ err_no_ioregion:
+	spi_master_put(master);
+	return status;
+}
+
+static void
+pl022_remove(struct amba_device *adev)
+{
+	struct pl022 *pl022 = amba_get_drvdata(adev);
+
+	if (!pl022)
+		return;
+
+	/*
+	 * undo pm_runtime_put() in probe.  I assume that we're not
+	 * accessing the primecell here.
+	 */
+	pm_runtime_get_noresume(&adev->dev);
+
+	load_ssp_default_config(pl022);
+	if (pl022->master_info->enable_dma)
+		pl022_dma_remove(pl022);
+
+	clk_disable_unprepare(pl022->clk);
+	amba_release_regions(adev);
+	tasklet_disable(&pl022->pump_transfers);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int pl022_suspend(struct device *dev)
+{
+	struct pl022 *pl022 = dev_get_drvdata(dev);
+	int ret;
+
+	ret = spi_master_suspend(pl022->master);
+	if (ret)
+		return ret;
+
+	ret = pm_runtime_force_suspend(dev);
+	if (ret) {
+		spi_master_resume(pl022->master);
+		return ret;
+	}
+
+	pinctrl_pm_select_sleep_state(dev);
+
+	dev_dbg(dev, "suspended\n");
+	return 0;
+}
+
+static int pl022_resume(struct device *dev)
+{
+	struct pl022 *pl022 = dev_get_drvdata(dev);
+	int ret;
+
+	ret = pm_runtime_force_resume(dev);
+	if (ret)
+		dev_err(dev, "problem resuming\n");
+
+	/* Start the queue running */
+	ret = spi_master_resume(pl022->master);
+	if (!ret)
+		dev_dbg(dev, "resumed\n");
+
+	return ret;
+}
+#endif
+
+#ifdef CONFIG_PM
+static int pl022_runtime_suspend(struct device *dev)
+{
+	struct pl022 *pl022 = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(pl022->clk);
+	pinctrl_pm_select_idle_state(dev);
+
+	return 0;
+}
+
+static int pl022_runtime_resume(struct device *dev)
+{
+	struct pl022 *pl022 = dev_get_drvdata(dev);
+
+	pinctrl_pm_select_default_state(dev);
+	clk_prepare_enable(pl022->clk);
+
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops pl022_dev_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(pl022_suspend, pl022_resume)
+	SET_RUNTIME_PM_OPS(pl022_runtime_suspend, pl022_runtime_resume, NULL)
+};
+
+static struct vendor_data vendor_arm = {
+	.fifodepth = 8,
+	.max_bpw = 16,
+	.unidir = false,
+	.extended_cr = false,
+	.pl023 = false,
+	.loopback = true,
+	.internal_cs_ctrl = false,
+};
+
+static struct vendor_data vendor_st = {
+	.fifodepth = 32,
+	.max_bpw = 32,
+	.unidir = false,
+	.extended_cr = true,
+	.pl023 = false,
+	.loopback = true,
+	.internal_cs_ctrl = false,
+};
+
+static struct vendor_data vendor_st_pl023 = {
+	.fifodepth = 32,
+	.max_bpw = 32,
+	.unidir = false,
+	.extended_cr = true,
+	.pl023 = true,
+	.loopback = false,
+	.internal_cs_ctrl = false,
+};
+
+static struct vendor_data vendor_lsi = {
+	.fifodepth = 8,
+	.max_bpw = 16,
+	.unidir = false,
+	.extended_cr = false,
+	.pl023 = false,
+	.loopback = true,
+	.internal_cs_ctrl = true,
+};
+
+static const struct amba_id pl022_ids[] = {
+	{
+		/*
+		 * ARM PL022 variant, this has a 16bit wide
+		 * and 8 locations deep TX/RX FIFO
+		 */
+		.id	= 0x00041022,
+		.mask	= 0x000fffff,
+		.data	= &vendor_arm,
+	},
+	{
+		/*
+		 * ST Micro derivative, this has 32bit wide
+		 * and 32 locations deep TX/RX FIFO
+		 */
+		.id	= 0x01080022,
+		.mask	= 0xffffffff,
+		.data	= &vendor_st,
+	},
+	{
+		/*
+		 * ST-Ericsson derivative "PL023" (this is not
+		 * an official ARM number), this is a PL022 SSP block
+		 * stripped to SPI mode only, it has 32bit wide
+		 * and 32 locations deep TX/RX FIFO but no extended
+		 * CR0/CR1 register
+		 */
+		.id	= 0x00080023,
+		.mask	= 0xffffffff,
+		.data	= &vendor_st_pl023,
+	},
+	{
+		/*
+		 * PL022 variant that has a chip select control register whih
+		 * allows control of 5 output signals nCS[0:4].
+		 */
+		.id	= 0x000b6022,
+		.mask	= 0x000fffff,
+		.data	= &vendor_lsi,
+	},
+	{ 0, 0 },
+};
+
+MODULE_DEVICE_TABLE(amba, pl022_ids);
+
+static struct amba_driver pl022_driver = {
+	.drv = {
+		.name	= "ssp-pl022",
+		.pm	= &pl022_dev_pm_ops,
+	},
+	.id_table	= pl022_ids,
+	.probe		= pl022_probe,
+	.remove		= pl022_remove,
+};
+
+static int __init pl022_init(void)
+{
+	return amba_driver_register(&pl022_driver);
+}
+subsys_initcall(pl022_init);
+
+static void __exit pl022_exit(void)
+{
+	amba_driver_unregister(&pl022_driver);
+}
+module_exit(pl022_exit);
+
+MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
+MODULE_DESCRIPTION("PL022 SSP Controller Driver");
+MODULE_LICENSE("GPL");