spi: Delete Atmel AT91 SPI driver

Message ID 20180904094922.8131-1-linus.walleij@linaro.org
State New
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Series
  • spi: Delete Atmel AT91 SPI driver
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Commit Message

Linus Walleij Sept. 4, 2018, 9:49 a.m.
This driver depends on the deleted AT91 architecture and cause
me headaches from a GPIO point of view. It is unused so delete
it.

Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

---
 drivers/spi/Kconfig     |    7 -
 drivers/spi/Makefile    |    1 -
 drivers/spi/spi-atmel.c | 1843 ---------------------------------------
 3 files changed, 1851 deletions(-)
 delete mode 100644 drivers/spi/spi-atmel.c

-- 
2.17.1

Patch

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 671d078349cc..6624f43268d2 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -76,13 +76,6 @@  config SPI_ARMADA_3700
 	  This enables support for the SPI controller present on the
 	  Marvell Armada 3700 SoCs.
 
-config SPI_ATMEL
-	tristate "Atmel SPI Controller"
-	depends on ARCH_AT91 || COMPILE_TEST
-	help
-	  This selects a driver for the Atmel SPI Controller, present on
-	  many AT91 ARM chips.
-
 config SPI_AU1550
 	tristate "Au1550/Au1200/Au1300 SPI Controller"
 	depends on MIPS_ALCHEMY
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index a90d55970036..088cc3f5616f 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -15,7 +15,6 @@  obj-$(CONFIG_SPI_LOOPBACK_TEST)		+= spi-loopback-test.o
 # SPI master controller drivers (bus)
 obj-$(CONFIG_SPI_ALTERA)		+= spi-altera.o
 obj-$(CONFIG_SPI_ARMADA_3700)		+= spi-armada-3700.o
-obj-$(CONFIG_SPI_ATMEL)			+= spi-atmel.o
 obj-$(CONFIG_SPI_ATH79)			+= spi-ath79.o
 obj-$(CONFIG_SPI_AU1550)		+= spi-au1550.o
 obj-$(CONFIG_SPI_AXI_SPI_ENGINE)	+= spi-axi-spi-engine.o
diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
deleted file mode 100644
index 3f890d162934..000000000000
--- a/drivers/spi/spi-atmel.c
+++ /dev/null
@@ -1,1843 +0,0 @@ 
-/*
- * Driver for Atmel AT32 and AT91 SPI Controllers
- *
- * Copyright (C) 2006 Atmel Corporation
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-
-#include <linux/kernel.h>
-#include <linux/clk.h>
-#include <linux/module.h>
-#include <linux/platform_device.h>
-#include <linux/delay.h>
-#include <linux/dma-mapping.h>
-#include <linux/dmaengine.h>
-#include <linux/err.h>
-#include <linux/interrupt.h>
-#include <linux/spi/spi.h>
-#include <linux/slab.h>
-#include <linux/platform_data/dma-atmel.h>
-#include <linux/of.h>
-
-#include <linux/io.h>
-#include <linux/gpio.h>
-#include <linux/of_gpio.h>
-#include <linux/pinctrl/consumer.h>
-#include <linux/pm_runtime.h>
-
-/* SPI register offsets */
-#define SPI_CR					0x0000
-#define SPI_MR					0x0004
-#define SPI_RDR					0x0008
-#define SPI_TDR					0x000c
-#define SPI_SR					0x0010
-#define SPI_IER					0x0014
-#define SPI_IDR					0x0018
-#define SPI_IMR					0x001c
-#define SPI_CSR0				0x0030
-#define SPI_CSR1				0x0034
-#define SPI_CSR2				0x0038
-#define SPI_CSR3				0x003c
-#define SPI_FMR					0x0040
-#define SPI_FLR					0x0044
-#define SPI_VERSION				0x00fc
-#define SPI_RPR					0x0100
-#define SPI_RCR					0x0104
-#define SPI_TPR					0x0108
-#define SPI_TCR					0x010c
-#define SPI_RNPR				0x0110
-#define SPI_RNCR				0x0114
-#define SPI_TNPR				0x0118
-#define SPI_TNCR				0x011c
-#define SPI_PTCR				0x0120
-#define SPI_PTSR				0x0124
-
-/* Bitfields in CR */
-#define SPI_SPIEN_OFFSET			0
-#define SPI_SPIEN_SIZE				1
-#define SPI_SPIDIS_OFFSET			1
-#define SPI_SPIDIS_SIZE				1
-#define SPI_SWRST_OFFSET			7
-#define SPI_SWRST_SIZE				1
-#define SPI_LASTXFER_OFFSET			24
-#define SPI_LASTXFER_SIZE			1
-#define SPI_TXFCLR_OFFSET			16
-#define SPI_TXFCLR_SIZE				1
-#define SPI_RXFCLR_OFFSET			17
-#define SPI_RXFCLR_SIZE				1
-#define SPI_FIFOEN_OFFSET			30
-#define SPI_FIFOEN_SIZE				1
-#define SPI_FIFODIS_OFFSET			31
-#define SPI_FIFODIS_SIZE			1
-
-/* Bitfields in MR */
-#define SPI_MSTR_OFFSET				0
-#define SPI_MSTR_SIZE				1
-#define SPI_PS_OFFSET				1
-#define SPI_PS_SIZE				1
-#define SPI_PCSDEC_OFFSET			2
-#define SPI_PCSDEC_SIZE				1
-#define SPI_FDIV_OFFSET				3
-#define SPI_FDIV_SIZE				1
-#define SPI_MODFDIS_OFFSET			4
-#define SPI_MODFDIS_SIZE			1
-#define SPI_WDRBT_OFFSET			5
-#define SPI_WDRBT_SIZE				1
-#define SPI_LLB_OFFSET				7
-#define SPI_LLB_SIZE				1
-#define SPI_PCS_OFFSET				16
-#define SPI_PCS_SIZE				4
-#define SPI_DLYBCS_OFFSET			24
-#define SPI_DLYBCS_SIZE				8
-
-/* Bitfields in RDR */
-#define SPI_RD_OFFSET				0
-#define SPI_RD_SIZE				16
-
-/* Bitfields in TDR */
-#define SPI_TD_OFFSET				0
-#define SPI_TD_SIZE				16
-
-/* Bitfields in SR */
-#define SPI_RDRF_OFFSET				0
-#define SPI_RDRF_SIZE				1
-#define SPI_TDRE_OFFSET				1
-#define SPI_TDRE_SIZE				1
-#define SPI_MODF_OFFSET				2
-#define SPI_MODF_SIZE				1
-#define SPI_OVRES_OFFSET			3
-#define SPI_OVRES_SIZE				1
-#define SPI_ENDRX_OFFSET			4
-#define SPI_ENDRX_SIZE				1
-#define SPI_ENDTX_OFFSET			5
-#define SPI_ENDTX_SIZE				1
-#define SPI_RXBUFF_OFFSET			6
-#define SPI_RXBUFF_SIZE				1
-#define SPI_TXBUFE_OFFSET			7
-#define SPI_TXBUFE_SIZE				1
-#define SPI_NSSR_OFFSET				8
-#define SPI_NSSR_SIZE				1
-#define SPI_TXEMPTY_OFFSET			9
-#define SPI_TXEMPTY_SIZE			1
-#define SPI_SPIENS_OFFSET			16
-#define SPI_SPIENS_SIZE				1
-#define SPI_TXFEF_OFFSET			24
-#define SPI_TXFEF_SIZE				1
-#define SPI_TXFFF_OFFSET			25
-#define SPI_TXFFF_SIZE				1
-#define SPI_TXFTHF_OFFSET			26
-#define SPI_TXFTHF_SIZE				1
-#define SPI_RXFEF_OFFSET			27
-#define SPI_RXFEF_SIZE				1
-#define SPI_RXFFF_OFFSET			28
-#define SPI_RXFFF_SIZE				1
-#define SPI_RXFTHF_OFFSET			29
-#define SPI_RXFTHF_SIZE				1
-#define SPI_TXFPTEF_OFFSET			30
-#define SPI_TXFPTEF_SIZE			1
-#define SPI_RXFPTEF_OFFSET			31
-#define SPI_RXFPTEF_SIZE			1
-
-/* Bitfields in CSR0 */
-#define SPI_CPOL_OFFSET				0
-#define SPI_CPOL_SIZE				1
-#define SPI_NCPHA_OFFSET			1
-#define SPI_NCPHA_SIZE				1
-#define SPI_CSAAT_OFFSET			3
-#define SPI_CSAAT_SIZE				1
-#define SPI_BITS_OFFSET				4
-#define SPI_BITS_SIZE				4
-#define SPI_SCBR_OFFSET				8
-#define SPI_SCBR_SIZE				8
-#define SPI_DLYBS_OFFSET			16
-#define SPI_DLYBS_SIZE				8
-#define SPI_DLYBCT_OFFSET			24
-#define SPI_DLYBCT_SIZE				8
-
-/* Bitfields in RCR */
-#define SPI_RXCTR_OFFSET			0
-#define SPI_RXCTR_SIZE				16
-
-/* Bitfields in TCR */
-#define SPI_TXCTR_OFFSET			0
-#define SPI_TXCTR_SIZE				16
-
-/* Bitfields in RNCR */
-#define SPI_RXNCR_OFFSET			0
-#define SPI_RXNCR_SIZE				16
-
-/* Bitfields in TNCR */
-#define SPI_TXNCR_OFFSET			0
-#define SPI_TXNCR_SIZE				16
-
-/* Bitfields in PTCR */
-#define SPI_RXTEN_OFFSET			0
-#define SPI_RXTEN_SIZE				1
-#define SPI_RXTDIS_OFFSET			1
-#define SPI_RXTDIS_SIZE				1
-#define SPI_TXTEN_OFFSET			8
-#define SPI_TXTEN_SIZE				1
-#define SPI_TXTDIS_OFFSET			9
-#define SPI_TXTDIS_SIZE				1
-
-/* Bitfields in FMR */
-#define SPI_TXRDYM_OFFSET			0
-#define SPI_TXRDYM_SIZE				2
-#define SPI_RXRDYM_OFFSET			4
-#define SPI_RXRDYM_SIZE				2
-#define SPI_TXFTHRES_OFFSET			16
-#define SPI_TXFTHRES_SIZE			6
-#define SPI_RXFTHRES_OFFSET			24
-#define SPI_RXFTHRES_SIZE			6
-
-/* Bitfields in FLR */
-#define SPI_TXFL_OFFSET				0
-#define SPI_TXFL_SIZE				6
-#define SPI_RXFL_OFFSET				16
-#define SPI_RXFL_SIZE				6
-
-/* Constants for BITS */
-#define SPI_BITS_8_BPT				0
-#define SPI_BITS_9_BPT				1
-#define SPI_BITS_10_BPT				2
-#define SPI_BITS_11_BPT				3
-#define SPI_BITS_12_BPT				4
-#define SPI_BITS_13_BPT				5
-#define SPI_BITS_14_BPT				6
-#define SPI_BITS_15_BPT				7
-#define SPI_BITS_16_BPT				8
-#define SPI_ONE_DATA				0
-#define SPI_TWO_DATA				1
-#define SPI_FOUR_DATA				2
-
-/* Bit manipulation macros */
-#define SPI_BIT(name) \
-	(1 << SPI_##name##_OFFSET)
-#define SPI_BF(name, value) \
-	(((value) & ((1 << SPI_##name##_SIZE) - 1)) << SPI_##name##_OFFSET)
-#define SPI_BFEXT(name, value) \
-	(((value) >> SPI_##name##_OFFSET) & ((1 << SPI_##name##_SIZE) - 1))
-#define SPI_BFINS(name, value, old) \
-	(((old) & ~(((1 << SPI_##name##_SIZE) - 1) << SPI_##name##_OFFSET)) \
-	  | SPI_BF(name, value))
-
-/* Register access macros */
-#ifdef CONFIG_AVR32
-#define spi_readl(port, reg) \
-	__raw_readl((port)->regs + SPI_##reg)
-#define spi_writel(port, reg, value) \
-	__raw_writel((value), (port)->regs + SPI_##reg)
-
-#define spi_readw(port, reg) \
-	__raw_readw((port)->regs + SPI_##reg)
-#define spi_writew(port, reg, value) \
-	__raw_writew((value), (port)->regs + SPI_##reg)
-
-#define spi_readb(port, reg) \
-	__raw_readb((port)->regs + SPI_##reg)
-#define spi_writeb(port, reg, value) \
-	__raw_writeb((value), (port)->regs + SPI_##reg)
-#else
-#define spi_readl(port, reg) \
-	readl_relaxed((port)->regs + SPI_##reg)
-#define spi_writel(port, reg, value) \
-	writel_relaxed((value), (port)->regs + SPI_##reg)
-
-#define spi_readw(port, reg) \
-	readw_relaxed((port)->regs + SPI_##reg)
-#define spi_writew(port, reg, value) \
-	writew_relaxed((value), (port)->regs + SPI_##reg)
-
-#define spi_readb(port, reg) \
-	readb_relaxed((port)->regs + SPI_##reg)
-#define spi_writeb(port, reg, value) \
-	writeb_relaxed((value), (port)->regs + SPI_##reg)
-#endif
-/* use PIO for small transfers, avoiding DMA setup/teardown overhead and
- * cache operations; better heuristics consider wordsize and bitrate.
- */
-#define DMA_MIN_BYTES	16
-
-#define SPI_DMA_TIMEOUT		(msecs_to_jiffies(1000))
-
-#define AUTOSUSPEND_TIMEOUT	2000
-
-struct atmel_spi_caps {
-	bool	is_spi2;
-	bool	has_wdrbt;
-	bool	has_dma_support;
-	bool	has_pdc_support;
-};
-
-/*
- * The core SPI transfer engine just talks to a register bank to set up
- * DMA transfers; transfer queue progress is driven by IRQs.  The clock
- * framework provides the base clock, subdivided for each spi_device.
- */
-struct atmel_spi {
-	spinlock_t		lock;
-	unsigned long		flags;
-
-	phys_addr_t		phybase;
-	void __iomem		*regs;
-	int			irq;
-	struct clk		*clk;
-	struct platform_device	*pdev;
-	unsigned long		spi_clk;
-
-	struct spi_transfer	*current_transfer;
-	int			current_remaining_bytes;
-	int			done_status;
-	dma_addr_t		dma_addr_rx_bbuf;
-	dma_addr_t		dma_addr_tx_bbuf;
-	void			*addr_rx_bbuf;
-	void			*addr_tx_bbuf;
-
-	struct completion	xfer_completion;
-
-	struct atmel_spi_caps	caps;
-
-	bool			use_dma;
-	bool			use_pdc;
-	bool			use_cs_gpios;
-
-	bool			keep_cs;
-	bool			cs_active;
-
-	u32			fifo_size;
-};
-
-/* Controller-specific per-slave state */
-struct atmel_spi_device {
-	unsigned int		npcs_pin;
-	u32			csr;
-};
-
-#define SPI_MAX_DMA_XFER	65535 /* true for both PDC and DMA */
-#define INVALID_DMA_ADDRESS	0xffffffff
-
-/*
- * Version 2 of the SPI controller has
- *  - CR.LASTXFER
- *  - SPI_MR.DIV32 may become FDIV or must-be-zero (here: always zero)
- *  - SPI_SR.TXEMPTY, SPI_SR.NSSR (and corresponding irqs)
- *  - SPI_CSRx.CSAAT
- *  - SPI_CSRx.SBCR allows faster clocking
- */
-static bool atmel_spi_is_v2(struct atmel_spi *as)
-{
-	return as->caps.is_spi2;
-}
-
-/*
- * Earlier SPI controllers (e.g. on at91rm9200) have a design bug whereby
- * they assume that spi slave device state will not change on deselect, so
- * that automagic deselection is OK.  ("NPCSx rises if no data is to be
- * transmitted")  Not so!  Workaround uses nCSx pins as GPIOs; or newer
- * controllers have CSAAT and friends.
- *
- * Since the CSAAT functionality is a bit weird on newer controllers as
- * well, we use GPIO to control nCSx pins on all controllers, updating
- * MR.PCS to avoid confusing the controller.  Using GPIOs also lets us
- * support active-high chipselects despite the controller's belief that
- * only active-low devices/systems exists.
- *
- * However, at91rm9200 has a second erratum whereby nCS0 doesn't work
- * right when driven with GPIO.  ("Mode Fault does not allow more than one
- * Master on Chip Select 0.")  No workaround exists for that ... so for
- * nCS0 on that chip, we (a) don't use the GPIO, (b) can't support CS_HIGH,
- * and (c) will trigger that first erratum in some cases.
- */
-
-static void cs_activate(struct atmel_spi *as, struct spi_device *spi)
-{
-	struct atmel_spi_device *asd = spi->controller_state;
-	unsigned active = spi->mode & SPI_CS_HIGH;
-	u32 mr;
-
-	if (atmel_spi_is_v2(as)) {
-		spi_writel(as, CSR0 + 4 * spi->chip_select, asd->csr);
-		/* For the low SPI version, there is a issue that PDC transfer
-		 * on CS1,2,3 needs SPI_CSR0.BITS config as SPI_CSR1,2,3.BITS
-		 */
-		spi_writel(as, CSR0, asd->csr);
-		if (as->caps.has_wdrbt) {
-			spi_writel(as, MR,
-					SPI_BF(PCS, ~(0x01 << spi->chip_select))
-					| SPI_BIT(WDRBT)
-					| SPI_BIT(MODFDIS)
-					| SPI_BIT(MSTR));
-		} else {
-			spi_writel(as, MR,
-					SPI_BF(PCS, ~(0x01 << spi->chip_select))
-					| SPI_BIT(MODFDIS)
-					| SPI_BIT(MSTR));
-		}
-
-		mr = spi_readl(as, MR);
-		if (as->use_cs_gpios)
-			gpio_set_value(asd->npcs_pin, active);
-	} else {
-		u32 cpol = (spi->mode & SPI_CPOL) ? SPI_BIT(CPOL) : 0;
-		int i;
-		u32 csr;
-
-		/* Make sure clock polarity is correct */
-		for (i = 0; i < spi->master->num_chipselect; i++) {
-			csr = spi_readl(as, CSR0 + 4 * i);
-			if ((csr ^ cpol) & SPI_BIT(CPOL))
-				spi_writel(as, CSR0 + 4 * i,
-						csr ^ SPI_BIT(CPOL));
-		}
-
-		mr = spi_readl(as, MR);
-		mr = SPI_BFINS(PCS, ~(1 << spi->chip_select), mr);
-		if (as->use_cs_gpios && spi->chip_select != 0)
-			gpio_set_value(asd->npcs_pin, active);
-		spi_writel(as, MR, mr);
-	}
-
-	dev_dbg(&spi->dev, "activate %u%s, mr %08x\n",
-			asd->npcs_pin, active ? " (high)" : "",
-			mr);
-}
-
-static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi)
-{
-	struct atmel_spi_device *asd = spi->controller_state;
-	unsigned active = spi->mode & SPI_CS_HIGH;
-	u32 mr;
-
-	/* only deactivate *this* device; sometimes transfers to
-	 * another device may be active when this routine is called.
-	 */
-	mr = spi_readl(as, MR);
-	if (~SPI_BFEXT(PCS, mr) & (1 << spi->chip_select)) {
-		mr = SPI_BFINS(PCS, 0xf, mr);
-		spi_writel(as, MR, mr);
-	}
-
-	dev_dbg(&spi->dev, "DEactivate %u%s, mr %08x\n",
-			asd->npcs_pin, active ? " (low)" : "",
-			mr);
-
-	if (!as->use_cs_gpios)
-		spi_writel(as, CR, SPI_BIT(LASTXFER));
-	else if (atmel_spi_is_v2(as) || spi->chip_select != 0)
-		gpio_set_value(asd->npcs_pin, !active);
-}
-
-static void atmel_spi_lock(struct atmel_spi *as) __acquires(&as->lock)
-{
-	spin_lock_irqsave(&as->lock, as->flags);
-}
-
-static void atmel_spi_unlock(struct atmel_spi *as) __releases(&as->lock)
-{
-	spin_unlock_irqrestore(&as->lock, as->flags);
-}
-
-static inline bool atmel_spi_is_vmalloc_xfer(struct spi_transfer *xfer)
-{
-	return is_vmalloc_addr(xfer->tx_buf) || is_vmalloc_addr(xfer->rx_buf);
-}
-
-static inline bool atmel_spi_use_dma(struct atmel_spi *as,
-				struct spi_transfer *xfer)
-{
-	return as->use_dma && xfer->len >= DMA_MIN_BYTES;
-}
-
-static bool atmel_spi_can_dma(struct spi_master *master,
-			      struct spi_device *spi,
-			      struct spi_transfer *xfer)
-{
-	struct atmel_spi *as = spi_master_get_devdata(master);
-
-	if (IS_ENABLED(CONFIG_SOC_SAM_V4_V5))
-		return atmel_spi_use_dma(as, xfer) &&
-			!atmel_spi_is_vmalloc_xfer(xfer);
-	else
-		return atmel_spi_use_dma(as, xfer);
-
-}
-
-static int atmel_spi_dma_slave_config(struct atmel_spi *as,
-				struct dma_slave_config *slave_config,
-				u8 bits_per_word)
-{
-	struct spi_master *master = platform_get_drvdata(as->pdev);
-	int err = 0;
-
-	if (bits_per_word > 8) {
-		slave_config->dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
-		slave_config->src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
-	} else {
-		slave_config->dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
-		slave_config->src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
-	}
-
-	slave_config->dst_addr = (dma_addr_t)as->phybase + SPI_TDR;
-	slave_config->src_addr = (dma_addr_t)as->phybase + SPI_RDR;
-	slave_config->src_maxburst = 1;
-	slave_config->dst_maxburst = 1;
-	slave_config->device_fc = false;
-
-	/*
-	 * This driver uses fixed peripheral select mode (PS bit set to '0' in
-	 * the Mode Register).
-	 * So according to the datasheet, when FIFOs are available (and
-	 * enabled), the Transmit FIFO operates in Multiple Data Mode.
-	 * In this mode, up to 2 data, not 4, can be written into the Transmit
-	 * Data Register in a single access.
-	 * However, the first data has to be written into the lowest 16 bits and
-	 * the second data into the highest 16 bits of the Transmit
-	 * Data Register. For 8bit data (the most frequent case), it would
-	 * require to rework tx_buf so each data would actualy fit 16 bits.
-	 * So we'd rather write only one data at the time. Hence the transmit
-	 * path works the same whether FIFOs are available (and enabled) or not.
-	 */
-	slave_config->direction = DMA_MEM_TO_DEV;
-	if (dmaengine_slave_config(master->dma_tx, slave_config)) {
-		dev_err(&as->pdev->dev,
-			"failed to configure tx dma channel\n");
-		err = -EINVAL;
-	}
-
-	/*
-	 * This driver configures the spi controller for master mode (MSTR bit
-	 * set to '1' in the Mode Register).
-	 * So according to the datasheet, when FIFOs are available (and
-	 * enabled), the Receive FIFO operates in Single Data Mode.
-	 * So the receive path works the same whether FIFOs are available (and
-	 * enabled) or not.
-	 */
-	slave_config->direction = DMA_DEV_TO_MEM;
-	if (dmaengine_slave_config(master->dma_rx, slave_config)) {
-		dev_err(&as->pdev->dev,
-			"failed to configure rx dma channel\n");
-		err = -EINVAL;
-	}
-
-	return err;
-}
-
-static int atmel_spi_configure_dma(struct spi_master *master,
-				   struct atmel_spi *as)
-{
-	struct dma_slave_config	slave_config;
-	struct device *dev = &as->pdev->dev;
-	int err;
-
-	dma_cap_mask_t mask;
-	dma_cap_zero(mask);
-	dma_cap_set(DMA_SLAVE, mask);
-
-	master->dma_tx = dma_request_slave_channel_reason(dev, "tx");
-	if (IS_ERR(master->dma_tx)) {
-		err = PTR_ERR(master->dma_tx);
-		if (err == -EPROBE_DEFER) {
-			dev_warn(dev, "no DMA channel available at the moment\n");
-			goto error_clear;
-		}
-		dev_err(dev,
-			"DMA TX channel not available, SPI unable to use DMA\n");
-		err = -EBUSY;
-		goto error_clear;
-	}
-
-	/*
-	 * No reason to check EPROBE_DEFER here since we have already requested
-	 * tx channel. If it fails here, it's for another reason.
-	 */
-	master->dma_rx = dma_request_slave_channel(dev, "rx");
-
-	if (!master->dma_rx) {
-		dev_err(dev,
-			"DMA RX channel not available, SPI unable to use DMA\n");
-		err = -EBUSY;
-		goto error;
-	}
-
-	err = atmel_spi_dma_slave_config(as, &slave_config, 8);
-	if (err)
-		goto error;
-
-	dev_info(&as->pdev->dev,
-			"Using %s (tx) and %s (rx) for DMA transfers\n",
-			dma_chan_name(master->dma_tx),
-			dma_chan_name(master->dma_rx));
-
-	return 0;
-error:
-	if (master->dma_rx)
-		dma_release_channel(master->dma_rx);
-	if (!IS_ERR(master->dma_tx))
-		dma_release_channel(master->dma_tx);
-error_clear:
-	master->dma_tx = master->dma_rx = NULL;
-	return err;
-}
-
-static void atmel_spi_stop_dma(struct spi_master *master)
-{
-	if (master->dma_rx)
-		dmaengine_terminate_all(master->dma_rx);
-	if (master->dma_tx)
-		dmaengine_terminate_all(master->dma_tx);
-}
-
-static void atmel_spi_release_dma(struct spi_master *master)
-{
-	if (master->dma_rx) {
-		dma_release_channel(master->dma_rx);
-		master->dma_rx = NULL;
-	}
-	if (master->dma_tx) {
-		dma_release_channel(master->dma_tx);
-		master->dma_tx = NULL;
-	}
-}
-
-/* This function is called by the DMA driver from tasklet context */
-static void dma_callback(void *data)
-{
-	struct spi_master	*master = data;
-	struct atmel_spi	*as = spi_master_get_devdata(master);
-
-	if (is_vmalloc_addr(as->current_transfer->rx_buf) &&
-	    IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) {
-		memcpy(as->current_transfer->rx_buf, as->addr_rx_bbuf,
-		       as->current_transfer->len);
-	}
-	complete(&as->xfer_completion);
-}
-
-/*
- * Next transfer using PIO without FIFO.
- */
-static void atmel_spi_next_xfer_single(struct spi_master *master,
-				       struct spi_transfer *xfer)
-{
-	struct atmel_spi	*as = spi_master_get_devdata(master);
-	unsigned long xfer_pos = xfer->len - as->current_remaining_bytes;
-
-	dev_vdbg(master->dev.parent, "atmel_spi_next_xfer_pio\n");
-
-	/* Make sure data is not remaining in RDR */
-	spi_readl(as, RDR);
-	while (spi_readl(as, SR) & SPI_BIT(RDRF)) {
-		spi_readl(as, RDR);
-		cpu_relax();
-	}
-
-	if (xfer->bits_per_word > 8)
-		spi_writel(as, TDR, *(u16 *)(xfer->tx_buf + xfer_pos));
-	else
-		spi_writel(as, TDR, *(u8 *)(xfer->tx_buf + xfer_pos));
-
-	dev_dbg(master->dev.parent,
-		"  start pio xfer %p: len %u tx %p rx %p bitpw %d\n",
-		xfer, xfer->len, xfer->tx_buf, xfer->rx_buf,
-		xfer->bits_per_word);
-
-	/* Enable relevant interrupts */
-	spi_writel(as, IER, SPI_BIT(RDRF) | SPI_BIT(OVRES));
-}
-
-/*
- * Next transfer using PIO with FIFO.
- */
-static void atmel_spi_next_xfer_fifo(struct spi_master *master,
-				     struct spi_transfer *xfer)
-{
-	struct atmel_spi *as = spi_master_get_devdata(master);
-	u32 current_remaining_data, num_data;
-	u32 offset = xfer->len - as->current_remaining_bytes;
-	const u16 *words = (const u16 *)((u8 *)xfer->tx_buf + offset);
-	const u8  *bytes = (const u8  *)((u8 *)xfer->tx_buf + offset);
-	u16 td0, td1;
-	u32 fifomr;
-
-	dev_vdbg(master->dev.parent, "atmel_spi_next_xfer_fifo\n");
-
-	/* Compute the number of data to transfer in the current iteration */
-	current_remaining_data = ((xfer->bits_per_word > 8) ?
-				  ((u32)as->current_remaining_bytes >> 1) :
-				  (u32)as->current_remaining_bytes);
-	num_data = min(current_remaining_data, as->fifo_size);
-
-	/* Flush RX and TX FIFOs */
-	spi_writel(as, CR, SPI_BIT(RXFCLR) | SPI_BIT(TXFCLR));
-	while (spi_readl(as, FLR))
-		cpu_relax();
-
-	/* Set RX FIFO Threshold to the number of data to transfer */
-	fifomr = spi_readl(as, FMR);
-	spi_writel(as, FMR, SPI_BFINS(RXFTHRES, num_data, fifomr));
-
-	/* Clear FIFO flags in the Status Register, especially RXFTHF */
-	(void)spi_readl(as, SR);
-
-	/* Fill TX FIFO */
-	while (num_data >= 2) {
-		if (xfer->bits_per_word > 8) {
-			td0 = *words++;
-			td1 = *words++;
-		} else {
-			td0 = *bytes++;
-			td1 = *bytes++;
-		}
-
-		spi_writel(as, TDR, (td1 << 16) | td0);
-		num_data -= 2;
-	}
-
-	if (num_data) {
-		if (xfer->bits_per_word > 8)
-			td0 = *words++;
-		else
-			td0 = *bytes++;
-
-		spi_writew(as, TDR, td0);
-		num_data--;
-	}
-
-	dev_dbg(master->dev.parent,
-		"  start fifo xfer %p: len %u tx %p rx %p bitpw %d\n",
-		xfer, xfer->len, xfer->tx_buf, xfer->rx_buf,
-		xfer->bits_per_word);
-
-	/*
-	 * Enable RX FIFO Threshold Flag interrupt to be notified about
-	 * transfer completion.
-	 */
-	spi_writel(as, IER, SPI_BIT(RXFTHF) | SPI_BIT(OVRES));
-}
-
-/*
- * Next transfer using PIO.
- */
-static void atmel_spi_next_xfer_pio(struct spi_master *master,
-				    struct spi_transfer *xfer)
-{
-	struct atmel_spi *as = spi_master_get_devdata(master);
-
-	if (as->fifo_size)
-		atmel_spi_next_xfer_fifo(master, xfer);
-	else
-		atmel_spi_next_xfer_single(master, xfer);
-}
-
-/*
- * Submit next transfer for DMA.
- */
-static int atmel_spi_next_xfer_dma_submit(struct spi_master *master,
-				struct spi_transfer *xfer,
-				u32 *plen)
-{
-	struct atmel_spi	*as = spi_master_get_devdata(master);
-	struct dma_chan		*rxchan = master->dma_rx;
-	struct dma_chan		*txchan = master->dma_tx;
-	struct dma_async_tx_descriptor *rxdesc;
-	struct dma_async_tx_descriptor *txdesc;
-	struct dma_slave_config	slave_config;
-	dma_cookie_t		cookie;
-
-	dev_vdbg(master->dev.parent, "atmel_spi_next_xfer_dma_submit\n");
-
-	/* Check that the channels are available */
-	if (!rxchan || !txchan)
-		return -ENODEV;
-
-	/* release lock for DMA operations */
-	atmel_spi_unlock(as);
-
-	*plen = xfer->len;
-
-	if (atmel_spi_dma_slave_config(as, &slave_config,
-				       xfer->bits_per_word))
-		goto err_exit;
-
-	/* Send both scatterlists */
-	if (atmel_spi_is_vmalloc_xfer(xfer) &&
-	    IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) {
-		rxdesc = dmaengine_prep_slave_single(rxchan,
-						     as->dma_addr_rx_bbuf,
-						     xfer->len,
-						     DMA_DEV_TO_MEM,
-						     DMA_PREP_INTERRUPT |
-						     DMA_CTRL_ACK);
-	} else {
-		rxdesc = dmaengine_prep_slave_sg(rxchan,
-						 xfer->rx_sg.sgl,
-						 xfer->rx_sg.nents,
-						 DMA_DEV_TO_MEM,
-						 DMA_PREP_INTERRUPT |
-						 DMA_CTRL_ACK);
-	}
-	if (!rxdesc)
-		goto err_dma;
-
-	if (atmel_spi_is_vmalloc_xfer(xfer) &&
-	    IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) {
-		memcpy(as->addr_tx_bbuf, xfer->tx_buf, xfer->len);
-		txdesc = dmaengine_prep_slave_single(txchan,
-						     as->dma_addr_tx_bbuf,
-						     xfer->len, DMA_MEM_TO_DEV,
-						     DMA_PREP_INTERRUPT |
-						     DMA_CTRL_ACK);
-	} else {
-		txdesc = dmaengine_prep_slave_sg(txchan,
-						 xfer->tx_sg.sgl,
-						 xfer->tx_sg.nents,
-						 DMA_MEM_TO_DEV,
-						 DMA_PREP_INTERRUPT |
-						 DMA_CTRL_ACK);
-	}
-	if (!txdesc)
-		goto err_dma;
-
-	dev_dbg(master->dev.parent,
-		"  start dma xfer %p: len %u tx %p/%08llx rx %p/%08llx\n",
-		xfer, xfer->len, xfer->tx_buf, (unsigned long long)xfer->tx_dma,
-		xfer->rx_buf, (unsigned long long)xfer->rx_dma);
-
-	/* Enable relevant interrupts */
-	spi_writel(as, IER, SPI_BIT(OVRES));
-
-	/* Put the callback on the RX transfer only, that should finish last */
-	rxdesc->callback = dma_callback;
-	rxdesc->callback_param = master;
-
-	/* Submit and fire RX and TX with TX last so we're ready to read! */
-	cookie = rxdesc->tx_submit(rxdesc);
-	if (dma_submit_error(cookie))
-		goto err_dma;
-	cookie = txdesc->tx_submit(txdesc);
-	if (dma_submit_error(cookie))
-		goto err_dma;
-	rxchan->device->device_issue_pending(rxchan);
-	txchan->device->device_issue_pending(txchan);
-
-	/* take back lock */
-	atmel_spi_lock(as);
-	return 0;
-
-err_dma:
-	spi_writel(as, IDR, SPI_BIT(OVRES));
-	atmel_spi_stop_dma(master);
-err_exit:
-	atmel_spi_lock(as);
-	return -ENOMEM;
-}
-
-static void atmel_spi_next_xfer_data(struct spi_master *master,
-				struct spi_transfer *xfer,
-				dma_addr_t *tx_dma,
-				dma_addr_t *rx_dma,
-				u32 *plen)
-{
-	*rx_dma = xfer->rx_dma + xfer->len - *plen;
-	*tx_dma = xfer->tx_dma + xfer->len - *plen;
-	if (*plen > master->max_dma_len)
-		*plen = master->max_dma_len;
-}
-
-static int atmel_spi_set_xfer_speed(struct atmel_spi *as,
-				    struct spi_device *spi,
-				    struct spi_transfer *xfer)
-{
-	u32			scbr, csr;
-	unsigned long		bus_hz;
-
-	/* v1 chips start out at half the peripheral bus speed. */
-	bus_hz = as->spi_clk;
-	if (!atmel_spi_is_v2(as))
-		bus_hz /= 2;
-
-	/*
-	 * Calculate the lowest divider that satisfies the
-	 * constraint, assuming div32/fdiv/mbz == 0.
-	 */
-	scbr = DIV_ROUND_UP(bus_hz, xfer->speed_hz);
-
-	/*
-	 * If the resulting divider doesn't fit into the
-	 * register bitfield, we can't satisfy the constraint.
-	 */
-	if (scbr >= (1 << SPI_SCBR_SIZE)) {
-		dev_err(&spi->dev,
-			"setup: %d Hz too slow, scbr %u; min %ld Hz\n",
-			xfer->speed_hz, scbr, bus_hz/255);
-		return -EINVAL;
-	}
-	if (scbr == 0) {
-		dev_err(&spi->dev,
-			"setup: %d Hz too high, scbr %u; max %ld Hz\n",
-			xfer->speed_hz, scbr, bus_hz);
-		return -EINVAL;
-	}
-	csr = spi_readl(as, CSR0 + 4 * spi->chip_select);
-	csr = SPI_BFINS(SCBR, scbr, csr);
-	spi_writel(as, CSR0 + 4 * spi->chip_select, csr);
-
-	return 0;
-}
-
-/*
- * Submit next transfer for PDC.
- * lock is held, spi irq is blocked
- */
-static void atmel_spi_pdc_next_xfer(struct spi_master *master,
-					struct spi_message *msg,
-					struct spi_transfer *xfer)
-{
-	struct atmel_spi	*as = spi_master_get_devdata(master);
-	u32			len;
-	dma_addr_t		tx_dma, rx_dma;
-
-	spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
-
-	len = as->current_remaining_bytes;
-	atmel_spi_next_xfer_data(master, xfer, &tx_dma, &rx_dma, &len);
-	as->current_remaining_bytes -= len;
-
-	spi_writel(as, RPR, rx_dma);
-	spi_writel(as, TPR, tx_dma);
-
-	if (msg->spi->bits_per_word > 8)
-		len >>= 1;
-	spi_writel(as, RCR, len);
-	spi_writel(as, TCR, len);
-
-	dev_dbg(&msg->spi->dev,
-		"  start xfer %p: len %u tx %p/%08llx rx %p/%08llx\n",
-		xfer, xfer->len, xfer->tx_buf,
-		(unsigned long long)xfer->tx_dma, xfer->rx_buf,
-		(unsigned long long)xfer->rx_dma);
-
-	if (as->current_remaining_bytes) {
-		len = as->current_remaining_bytes;
-		atmel_spi_next_xfer_data(master, xfer, &tx_dma, &rx_dma, &len);
-		as->current_remaining_bytes -= len;
-
-		spi_writel(as, RNPR, rx_dma);
-		spi_writel(as, TNPR, tx_dma);
-
-		if (msg->spi->bits_per_word > 8)
-			len >>= 1;
-		spi_writel(as, RNCR, len);
-		spi_writel(as, TNCR, len);
-
-		dev_dbg(&msg->spi->dev,
-			"  next xfer %p: len %u tx %p/%08llx rx %p/%08llx\n",
-			xfer, xfer->len, xfer->tx_buf,
-			(unsigned long long)xfer->tx_dma, xfer->rx_buf,
-			(unsigned long long)xfer->rx_dma);
-	}
-
-	/* REVISIT: We're waiting for RXBUFF before we start the next
-	 * transfer because we need to handle some difficult timing
-	 * issues otherwise. If we wait for TXBUFE in one transfer and
-	 * then starts waiting for RXBUFF in the next, it's difficult
-	 * to tell the difference between the RXBUFF interrupt we're
-	 * actually waiting for and the RXBUFF interrupt of the
-	 * previous transfer.
-	 *
-	 * It should be doable, though. Just not now...
-	 */
-	spi_writel(as, IER, SPI_BIT(RXBUFF) | SPI_BIT(OVRES));
-	spi_writel(as, PTCR, SPI_BIT(TXTEN) | SPI_BIT(RXTEN));
-}
-
-/*
- * For DMA, tx_buf/tx_dma have the same relationship as rx_buf/rx_dma:
- *  - The buffer is either valid for CPU access, else NULL
- *  - If the buffer is valid, so is its DMA address
- *
- * This driver manages the dma address unless message->is_dma_mapped.
- */
-static int
-atmel_spi_dma_map_xfer(struct atmel_spi *as, struct spi_transfer *xfer)
-{
-	struct device	*dev = &as->pdev->dev;
-
-	xfer->tx_dma = xfer->rx_dma = INVALID_DMA_ADDRESS;
-	if (xfer->tx_buf) {
-		/* tx_buf is a const void* where we need a void * for the dma
-		 * mapping */
-		void *nonconst_tx = (void *)xfer->tx_buf;
-
-		xfer->tx_dma = dma_map_single(dev,
-				nonconst_tx, xfer->len,
-				DMA_TO_DEVICE);
-		if (dma_mapping_error(dev, xfer->tx_dma))
-			return -ENOMEM;
-	}
-	if (xfer->rx_buf) {
-		xfer->rx_dma = dma_map_single(dev,
-				xfer->rx_buf, xfer->len,
-				DMA_FROM_DEVICE);
-		if (dma_mapping_error(dev, xfer->rx_dma)) {
-			if (xfer->tx_buf)
-				dma_unmap_single(dev,
-						xfer->tx_dma, xfer->len,
-						DMA_TO_DEVICE);
-			return -ENOMEM;
-		}
-	}
-	return 0;
-}
-
-static void atmel_spi_dma_unmap_xfer(struct spi_master *master,
-				     struct spi_transfer *xfer)
-{
-	if (xfer->tx_dma != INVALID_DMA_ADDRESS)
-		dma_unmap_single(master->dev.parent, xfer->tx_dma,
-				 xfer->len, DMA_TO_DEVICE);
-	if (xfer->rx_dma != INVALID_DMA_ADDRESS)
-		dma_unmap_single(master->dev.parent, xfer->rx_dma,
-				 xfer->len, DMA_FROM_DEVICE);
-}
-
-static void atmel_spi_disable_pdc_transfer(struct atmel_spi *as)
-{
-	spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
-}
-
-static void
-atmel_spi_pump_single_data(struct atmel_spi *as, struct spi_transfer *xfer)
-{
-	u8		*rxp;
-	u16		*rxp16;
-	unsigned long	xfer_pos = xfer->len - as->current_remaining_bytes;
-
-	if (xfer->bits_per_word > 8) {
-		rxp16 = (u16 *)(((u8 *)xfer->rx_buf) + xfer_pos);
-		*rxp16 = spi_readl(as, RDR);
-	} else {
-		rxp = ((u8 *)xfer->rx_buf) + xfer_pos;
-		*rxp = spi_readl(as, RDR);
-	}
-	if (xfer->bits_per_word > 8) {
-		if (as->current_remaining_bytes > 2)
-			as->current_remaining_bytes -= 2;
-		else
-			as->current_remaining_bytes = 0;
-	} else {
-		as->current_remaining_bytes--;
-	}
-}
-
-static void
-atmel_spi_pump_fifo_data(struct atmel_spi *as, struct spi_transfer *xfer)
-{
-	u32 fifolr = spi_readl(as, FLR);
-	u32 num_bytes, num_data = SPI_BFEXT(RXFL, fifolr);
-	u32 offset = xfer->len - as->current_remaining_bytes;
-	u16 *words = (u16 *)((u8 *)xfer->rx_buf + offset);
-	u8  *bytes = (u8  *)((u8 *)xfer->rx_buf + offset);
-	u16 rd; /* RD field is the lowest 16 bits of RDR */
-
-	/* Update the number of remaining bytes to transfer */
-	num_bytes = ((xfer->bits_per_word > 8) ?
-		     (num_data << 1) :
-		     num_data);
-
-	if (as->current_remaining_bytes > num_bytes)
-		as->current_remaining_bytes -= num_bytes;
-	else
-		as->current_remaining_bytes = 0;
-
-	/* Handle odd number of bytes when data are more than 8bit width */
-	if (xfer->bits_per_word > 8)
-		as->current_remaining_bytes &= ~0x1;
-
-	/* Read data */
-	while (num_data) {
-		rd = spi_readl(as, RDR);
-		if (xfer->bits_per_word > 8)
-			*words++ = rd;
-		else
-			*bytes++ = rd;
-		num_data--;
-	}
-}
-
-/* Called from IRQ
- *
- * Must update "current_remaining_bytes" to keep track of data
- * to transfer.
- */
-static void
-atmel_spi_pump_pio_data(struct atmel_spi *as, struct spi_transfer *xfer)
-{
-	if (as->fifo_size)
-		atmel_spi_pump_fifo_data(as, xfer);
-	else
-		atmel_spi_pump_single_data(as, xfer);
-}
-
-/* Interrupt
- *
- * No need for locking in this Interrupt handler: done_status is the
- * only information modified.
- */
-static irqreturn_t
-atmel_spi_pio_interrupt(int irq, void *dev_id)
-{
-	struct spi_master	*master = dev_id;
-	struct atmel_spi	*as = spi_master_get_devdata(master);
-	u32			status, pending, imr;
-	struct spi_transfer	*xfer;
-	int			ret = IRQ_NONE;
-
-	imr = spi_readl(as, IMR);
-	status = spi_readl(as, SR);
-	pending = status & imr;
-
-	if (pending & SPI_BIT(OVRES)) {
-		ret = IRQ_HANDLED;
-		spi_writel(as, IDR, SPI_BIT(OVRES));
-		dev_warn(master->dev.parent, "overrun\n");
-
-		/*
-		 * When we get an overrun, we disregard the current
-		 * transfer. Data will not be copied back from any
-		 * bounce buffer and msg->actual_len will not be
-		 * updated with the last xfer.
-		 *
-		 * We will also not process any remaning transfers in
-		 * the message.
-		 */
-		as->done_status = -EIO;
-		smp_wmb();
-
-		/* Clear any overrun happening while cleaning up */
-		spi_readl(as, SR);
-
-		complete(&as->xfer_completion);
-
-	} else if (pending & (SPI_BIT(RDRF) | SPI_BIT(RXFTHF))) {
-		atmel_spi_lock(as);
-
-		if (as->current_remaining_bytes) {
-			ret = IRQ_HANDLED;
-			xfer = as->current_transfer;
-			atmel_spi_pump_pio_data(as, xfer);
-			if (!as->current_remaining_bytes)
-				spi_writel(as, IDR, pending);
-
-			complete(&as->xfer_completion);
-		}
-
-		atmel_spi_unlock(as);
-	} else {
-		WARN_ONCE(pending, "IRQ not handled, pending = %x\n", pending);
-		ret = IRQ_HANDLED;
-		spi_writel(as, IDR, pending);
-	}
-
-	return ret;
-}
-
-static irqreturn_t
-atmel_spi_pdc_interrupt(int irq, void *dev_id)
-{
-	struct spi_master	*master = dev_id;
-	struct atmel_spi	*as = spi_master_get_devdata(master);
-	u32			status, pending, imr;
-	int			ret = IRQ_NONE;
-
-	imr = spi_readl(as, IMR);
-	status = spi_readl(as, SR);
-	pending = status & imr;
-
-	if (pending & SPI_BIT(OVRES)) {
-
-		ret = IRQ_HANDLED;
-
-		spi_writel(as, IDR, (SPI_BIT(RXBUFF) | SPI_BIT(ENDRX)
-				     | SPI_BIT(OVRES)));
-
-		/* Clear any overrun happening while cleaning up */
-		spi_readl(as, SR);
-
-		as->done_status = -EIO;
-
-		complete(&as->xfer_completion);
-
-	} else if (pending & (SPI_BIT(RXBUFF) | SPI_BIT(ENDRX))) {
-		ret = IRQ_HANDLED;
-
-		spi_writel(as, IDR, pending);
-
-		complete(&as->xfer_completion);
-	}
-
-	return ret;
-}
-
-static int atmel_spi_setup(struct spi_device *spi)
-{
-	struct atmel_spi	*as;
-	struct atmel_spi_device	*asd;
-	u32			csr;
-	unsigned int		bits = spi->bits_per_word;
-	unsigned int		npcs_pin;
-
-	as = spi_master_get_devdata(spi->master);
-
-	/* see notes above re chipselect */
-	if (!atmel_spi_is_v2(as)
-			&& spi->chip_select == 0
-			&& (spi->mode & SPI_CS_HIGH)) {
-		dev_dbg(&spi->dev, "setup: can't be active-high\n");
-		return -EINVAL;
-	}
-
-	csr = SPI_BF(BITS, bits - 8);
-	if (spi->mode & SPI_CPOL)
-		csr |= SPI_BIT(CPOL);
-	if (!(spi->mode & SPI_CPHA))
-		csr |= SPI_BIT(NCPHA);
-	if (!as->use_cs_gpios)
-		csr |= SPI_BIT(CSAAT);
-
-	/* DLYBS is mostly irrelevant since we manage chipselect using GPIOs.
-	 *
-	 * DLYBCT would add delays between words, slowing down transfers.
-	 * It could potentially be useful to cope with DMA bottlenecks, but
-	 * in those cases it's probably best to just use a lower bitrate.
-	 */
-	csr |= SPI_BF(DLYBS, 0);
-	csr |= SPI_BF(DLYBCT, 0);
-
-	/* chipselect must have been muxed as GPIO (e.g. in board setup) */
-	npcs_pin = (unsigned long)spi->controller_data;
-
-	if (!as->use_cs_gpios)
-		npcs_pin = spi->chip_select;
-	else if (gpio_is_valid(spi->cs_gpio))
-		npcs_pin = spi->cs_gpio;
-
-	asd = spi->controller_state;
-	if (!asd) {
-		asd = kzalloc(sizeof(struct atmel_spi_device), GFP_KERNEL);
-		if (!asd)
-			return -ENOMEM;
-
-		if (as->use_cs_gpios)
-			gpio_direction_output(npcs_pin,
-					      !(spi->mode & SPI_CS_HIGH));
-
-		asd->npcs_pin = npcs_pin;
-		spi->controller_state = asd;
-	}
-
-	asd->csr = csr;
-
-	dev_dbg(&spi->dev,
-		"setup: bpw %u mode 0x%x -> csr%d %08x\n",
-		bits, spi->mode, spi->chip_select, csr);
-
-	if (!atmel_spi_is_v2(as))
-		spi_writel(as, CSR0 + 4 * spi->chip_select, csr);
-
-	return 0;
-}
-
-static int atmel_spi_one_transfer(struct spi_master *master,
-					struct spi_message *msg,
-					struct spi_transfer *xfer)
-{
-	struct atmel_spi	*as;
-	struct spi_device	*spi = msg->spi;
-	u8			bits;
-	u32			len;
-	struct atmel_spi_device	*asd;
-	int			timeout;
-	int			ret;
-	unsigned long		dma_timeout;
-
-	as = spi_master_get_devdata(master);
-
-	if (!(xfer->tx_buf || xfer->rx_buf) && xfer->len) {
-		dev_dbg(&spi->dev, "missing rx or tx buf\n");
-		return -EINVAL;
-	}
-
-	asd = spi->controller_state;
-	bits = (asd->csr >> 4) & 0xf;
-	if (bits != xfer->bits_per_word - 8) {
-		dev_dbg(&spi->dev,
-			"you can't yet change bits_per_word in transfers\n");
-		return -ENOPROTOOPT;
-	}
-
-	/*
-	 * DMA map early, for performance (empties dcache ASAP) and
-	 * better fault reporting.
-	 */
-	if ((!msg->is_dma_mapped)
-		&& as->use_pdc) {
-		if (atmel_spi_dma_map_xfer(as, xfer) < 0)
-			return -ENOMEM;
-	}
-
-	atmel_spi_set_xfer_speed(as, msg->spi, xfer);
-
-	as->done_status = 0;
-	as->current_transfer = xfer;
-	as->current_remaining_bytes = xfer->len;
-	while (as->current_remaining_bytes) {
-		reinit_completion(&as->xfer_completion);
-
-		if (as->use_pdc) {
-			atmel_spi_pdc_next_xfer(master, msg, xfer);
-		} else if (atmel_spi_use_dma(as, xfer)) {
-			len = as->current_remaining_bytes;
-			ret = atmel_spi_next_xfer_dma_submit(master,
-								xfer, &len);
-			if (ret) {
-				dev_err(&spi->dev,
-					"unable to use DMA, fallback to PIO\n");
-				atmel_spi_next_xfer_pio(master, xfer);
-			} else {
-				as->current_remaining_bytes -= len;
-				if (as->current_remaining_bytes < 0)
-					as->current_remaining_bytes = 0;
-			}
-		} else {
-			atmel_spi_next_xfer_pio(master, xfer);
-		}
-
-		/* interrupts are disabled, so free the lock for schedule */
-		atmel_spi_unlock(as);
-		dma_timeout = wait_for_completion_timeout(&as->xfer_completion,
-							  SPI_DMA_TIMEOUT);
-		atmel_spi_lock(as);
-		if (WARN_ON(dma_timeout == 0)) {
-			dev_err(&spi->dev, "spi transfer timeout\n");
-			as->done_status = -EIO;
-		}
-
-		if (as->done_status)
-			break;
-	}
-
-	if (as->done_status) {
-		if (as->use_pdc) {
-			dev_warn(master->dev.parent,
-				"overrun (%u/%u remaining)\n",
-				spi_readl(as, TCR), spi_readl(as, RCR));
-
-			/*
-			 * Clean up DMA registers and make sure the data
-			 * registers are empty.
-			 */
-			spi_writel(as, RNCR, 0);
-			spi_writel(as, TNCR, 0);
-			spi_writel(as, RCR, 0);
-			spi_writel(as, TCR, 0);
-			for (timeout = 1000; timeout; timeout--)
-				if (spi_readl(as, SR) & SPI_BIT(TXEMPTY))
-					break;
-			if (!timeout)
-				dev_warn(master->dev.parent,
-					 "timeout waiting for TXEMPTY");
-			while (spi_readl(as, SR) & SPI_BIT(RDRF))
-				spi_readl(as, RDR);
-
-			/* Clear any overrun happening while cleaning up */
-			spi_readl(as, SR);
-
-		} else if (atmel_spi_use_dma(as, xfer)) {
-			atmel_spi_stop_dma(master);
-		}
-
-		if (!msg->is_dma_mapped
-			&& as->use_pdc)
-			atmel_spi_dma_unmap_xfer(master, xfer);
-
-		return 0;
-
-	} else {
-		/* only update length if no error */
-		msg->actual_length += xfer->len;
-	}
-
-	if (!msg->is_dma_mapped
-		&& as->use_pdc)
-		atmel_spi_dma_unmap_xfer(master, xfer);
-
-	if (xfer->delay_usecs)
-		udelay(xfer->delay_usecs);
-
-	if (xfer->cs_change) {
-		if (list_is_last(&xfer->transfer_list,
-				 &msg->transfers)) {
-			as->keep_cs = true;
-		} else {
-			as->cs_active = !as->cs_active;
-			if (as->cs_active)
-				cs_activate(as, msg->spi);
-			else
-				cs_deactivate(as, msg->spi);
-		}
-	}
-
-	return 0;
-}
-
-static int atmel_spi_transfer_one_message(struct spi_master *master,
-						struct spi_message *msg)
-{
-	struct atmel_spi *as;
-	struct spi_transfer *xfer;
-	struct spi_device *spi = msg->spi;
-	int ret = 0;
-
-	as = spi_master_get_devdata(master);
-
-	dev_dbg(&spi->dev, "new message %p submitted for %s\n",
-					msg, dev_name(&spi->dev));
-
-	atmel_spi_lock(as);
-	cs_activate(as, spi);
-
-	as->cs_active = true;
-	as->keep_cs = false;
-
-	msg->status = 0;
-	msg->actual_length = 0;
-
-	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
-		ret = atmel_spi_one_transfer(master, msg, xfer);
-		if (ret)
-			goto msg_done;
-	}
-
-	if (as->use_pdc)
-		atmel_spi_disable_pdc_transfer(as);
-
-	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
-		dev_dbg(&spi->dev,
-			"  xfer %p: len %u tx %p/%pad rx %p/%pad\n",
-			xfer, xfer->len,
-			xfer->tx_buf, &xfer->tx_dma,
-			xfer->rx_buf, &xfer->rx_dma);
-	}
-
-msg_done:
-	if (!as->keep_cs)
-		cs_deactivate(as, msg->spi);
-
-	atmel_spi_unlock(as);
-
-	msg->status = as->done_status;
-	spi_finalize_current_message(spi->master);
-
-	return ret;
-}
-
-static void atmel_spi_cleanup(struct spi_device *spi)
-{
-	struct atmel_spi_device	*asd = spi->controller_state;
-
-	if (!asd)
-		return;
-
-	spi->controller_state = NULL;
-	kfree(asd);
-}
-
-static inline unsigned int atmel_get_version(struct atmel_spi *as)
-{
-	return spi_readl(as, VERSION) & 0x00000fff;
-}
-
-static void atmel_get_caps(struct atmel_spi *as)
-{
-	unsigned int version;
-
-	version = atmel_get_version(as);
-
-	as->caps.is_spi2 = version > 0x121;
-	as->caps.has_wdrbt = version >= 0x210;
-	as->caps.has_dma_support = version >= 0x212;
-	as->caps.has_pdc_support = version < 0x212;
-}
-
-/*-------------------------------------------------------------------------*/
-static int atmel_spi_gpio_cs(struct platform_device *pdev)
-{
-	struct spi_master	*master = platform_get_drvdata(pdev);
-	struct atmel_spi	*as = spi_master_get_devdata(master);
-	struct device_node	*np = master->dev.of_node;
-	int			i;
-	int			ret = 0;
-	int			nb = 0;
-
-	if (!as->use_cs_gpios)
-		return 0;
-
-	if (!np)
-		return 0;
-
-	nb = of_gpio_named_count(np, "cs-gpios");
-	for (i = 0; i < nb; i++) {
-		int cs_gpio = of_get_named_gpio(pdev->dev.of_node,
-						"cs-gpios", i);
-
-		if (cs_gpio == -EPROBE_DEFER)
-			return cs_gpio;
-
-		if (gpio_is_valid(cs_gpio)) {
-			ret = devm_gpio_request(&pdev->dev, cs_gpio,
-						dev_name(&pdev->dev));
-			if (ret)
-				return ret;
-		}
-	}
-
-	return 0;
-}
-
-static void atmel_spi_init(struct atmel_spi *as)
-{
-	spi_writel(as, CR, SPI_BIT(SWRST));
-	spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
-
-	/* It is recommended to enable FIFOs first thing after reset */
-	if (as->fifo_size)
-		spi_writel(as, CR, SPI_BIT(FIFOEN));
-
-	if (as->caps.has_wdrbt) {
-		spi_writel(as, MR, SPI_BIT(WDRBT) | SPI_BIT(MODFDIS)
-				| SPI_BIT(MSTR));
-	} else {
-		spi_writel(as, MR, SPI_BIT(MSTR) | SPI_BIT(MODFDIS));
-	}
-
-	if (as->use_pdc)
-		spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
-	spi_writel(as, CR, SPI_BIT(SPIEN));
-}
-
-static int atmel_spi_probe(struct platform_device *pdev)
-{
-	struct resource		*regs;
-	int			irq;
-	struct clk		*clk;
-	int			ret;
-	struct spi_master	*master;
-	struct atmel_spi	*as;
-
-	/* Select default pin state */
-	pinctrl_pm_select_default_state(&pdev->dev);
-
-	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!regs)
-		return -ENXIO;
-
-	irq = platform_get_irq(pdev, 0);
-	if (irq < 0)
-		return irq;
-
-	clk = devm_clk_get(&pdev->dev, "spi_clk");
-	if (IS_ERR(clk))
-		return PTR_ERR(clk);
-
-	/* setup spi core then atmel-specific driver state */
-	ret = -ENOMEM;
-	master = spi_alloc_master(&pdev->dev, sizeof(*as));
-	if (!master)
-		goto out_free;
-
-	/* the spi->mode bits understood by this driver: */
-	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
-	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 16);
-	master->dev.of_node = pdev->dev.of_node;
-	master->bus_num = pdev->id;
-	master->num_chipselect = master->dev.of_node ? 0 : 4;
-	master->setup = atmel_spi_setup;
-	master->flags = (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX);
-	master->transfer_one_message = atmel_spi_transfer_one_message;
-	master->cleanup = atmel_spi_cleanup;
-	master->auto_runtime_pm = true;
-	master->max_dma_len = SPI_MAX_DMA_XFER;
-	master->can_dma = atmel_spi_can_dma;
-	platform_set_drvdata(pdev, master);
-
-	as = spi_master_get_devdata(master);
-
-	spin_lock_init(&as->lock);
-
-	as->pdev = pdev;
-	as->regs = devm_ioremap_resource(&pdev->dev, regs);
-	if (IS_ERR(as->regs)) {
-		ret = PTR_ERR(as->regs);
-		goto out_unmap_regs;
-	}
-	as->phybase = regs->start;
-	as->irq = irq;
-	as->clk = clk;
-
-	init_completion(&as->xfer_completion);
-
-	atmel_get_caps(as);
-
-	as->use_cs_gpios = true;
-	if (atmel_spi_is_v2(as) &&
-	    pdev->dev.of_node &&
-	    !of_get_property(pdev->dev.of_node, "cs-gpios", NULL)) {
-		as->use_cs_gpios = false;
-		master->num_chipselect = 4;
-	}
-
-	ret = atmel_spi_gpio_cs(pdev);
-	if (ret)
-		goto out_unmap_regs;
-
-	as->use_dma = false;
-	as->use_pdc = false;
-	if (as->caps.has_dma_support) {
-		ret = atmel_spi_configure_dma(master, as);
-		if (ret == 0) {
-			as->use_dma = true;
-		} else if (ret == -EPROBE_DEFER) {
-			return ret;
-		}
-	} else if (as->caps.has_pdc_support) {
-		as->use_pdc = true;
-	}
-
-	if (IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) {
-		as->addr_rx_bbuf = dma_alloc_coherent(&pdev->dev,
-						      SPI_MAX_DMA_XFER,
-						      &as->dma_addr_rx_bbuf,
-						      GFP_KERNEL | GFP_DMA);
-		if (!as->addr_rx_bbuf) {
-			as->use_dma = false;
-		} else {
-			as->addr_tx_bbuf = dma_alloc_coherent(&pdev->dev,
-					SPI_MAX_DMA_XFER,
-					&as->dma_addr_tx_bbuf,
-					GFP_KERNEL | GFP_DMA);
-			if (!as->addr_tx_bbuf) {
-				as->use_dma = false;
-				dma_free_coherent(&pdev->dev, SPI_MAX_DMA_XFER,
-						  as->addr_rx_bbuf,
-						  as->dma_addr_rx_bbuf);
-			}
-		}
-		if (!as->use_dma)
-			dev_info(master->dev.parent,
-				 "  can not allocate dma coherent memory\n");
-	}
-
-	if (as->caps.has_dma_support && !as->use_dma)
-		dev_info(&pdev->dev, "Atmel SPI Controller using PIO only\n");
-
-	if (as->use_pdc) {
-		ret = devm_request_irq(&pdev->dev, irq, atmel_spi_pdc_interrupt,
-					0, dev_name(&pdev->dev), master);
-	} else {
-		ret = devm_request_irq(&pdev->dev, irq, atmel_spi_pio_interrupt,
-					0, dev_name(&pdev->dev), master);
-	}
-	if (ret)
-		goto out_unmap_regs;
-
-	/* Initialize the hardware */
-	ret = clk_prepare_enable(clk);
-	if (ret)
-		goto out_free_irq;
-
-	as->spi_clk = clk_get_rate(clk);
-
-	as->fifo_size = 0;
-	if (!of_property_read_u32(pdev->dev.of_node, "atmel,fifo-size",
-				  &as->fifo_size)) {
-		dev_info(&pdev->dev, "Using FIFO (%u data)\n", as->fifo_size);
-	}
-
-	atmel_spi_init(as);
-
-	pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_TIMEOUT);
-	pm_runtime_use_autosuspend(&pdev->dev);
-	pm_runtime_set_active(&pdev->dev);
-	pm_runtime_enable(&pdev->dev);
-
-	ret = devm_spi_register_master(&pdev->dev, master);
-	if (ret)
-		goto out_free_dma;
-
-	/* go! */
-	dev_info(&pdev->dev, "Atmel SPI Controller version 0x%x at 0x%08lx (irq %d)\n",
-			atmel_get_version(as), (unsigned long)regs->start,
-			irq);
-
-	return 0;
-
-out_free_dma:
-	pm_runtime_disable(&pdev->dev);
-	pm_runtime_set_suspended(&pdev->dev);
-
-	if (as->use_dma)
-		atmel_spi_release_dma(master);
-
-	spi_writel(as, CR, SPI_BIT(SWRST));
-	spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
-	clk_disable_unprepare(clk);
-out_free_irq:
-out_unmap_regs:
-out_free:
-	spi_master_put(master);
-	return ret;
-}
-
-static int atmel_spi_remove(struct platform_device *pdev)
-{
-	struct spi_master	*master = platform_get_drvdata(pdev);
-	struct atmel_spi	*as = spi_master_get_devdata(master);
-
-	pm_runtime_get_sync(&pdev->dev);
-
-	/* reset the hardware and block queue progress */
-	if (as->use_dma) {
-		atmel_spi_stop_dma(master);
-		atmel_spi_release_dma(master);
-		if (IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) {
-			dma_free_coherent(&pdev->dev, SPI_MAX_DMA_XFER,
-					  as->addr_tx_bbuf,
-					  as->dma_addr_tx_bbuf);
-			dma_free_coherent(&pdev->dev, SPI_MAX_DMA_XFER,
-					  as->addr_rx_bbuf,
-					  as->dma_addr_rx_bbuf);
-		}
-	}
-
-	spin_lock_irq(&as->lock);
-	spi_writel(as, CR, SPI_BIT(SWRST));
-	spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
-	spi_readl(as, SR);
-	spin_unlock_irq(&as->lock);
-
-	clk_disable_unprepare(as->clk);
-
-	pm_runtime_put_noidle(&pdev->dev);
-	pm_runtime_disable(&pdev->dev);
-
-	return 0;
-}
-
-#ifdef CONFIG_PM
-static int atmel_spi_runtime_suspend(struct device *dev)
-{
-	struct spi_master *master = dev_get_drvdata(dev);
-	struct atmel_spi *as = spi_master_get_devdata(master);
-
-	clk_disable_unprepare(as->clk);
-	pinctrl_pm_select_sleep_state(dev);
-
-	return 0;
-}
-
-static int atmel_spi_runtime_resume(struct device *dev)
-{
-	struct spi_master *master = dev_get_drvdata(dev);
-	struct atmel_spi *as = spi_master_get_devdata(master);
-
-	pinctrl_pm_select_default_state(dev);
-
-	return clk_prepare_enable(as->clk);
-}
-
-#ifdef CONFIG_PM_SLEEP
-static int atmel_spi_suspend(struct device *dev)
-{
-	struct spi_master *master = dev_get_drvdata(dev);
-	int ret;
-
-	/* Stop the queue running */
-	ret = spi_master_suspend(master);
-	if (ret) {
-		dev_warn(dev, "cannot suspend master\n");
-		return ret;
-	}
-
-	if (!pm_runtime_suspended(dev))
-		atmel_spi_runtime_suspend(dev);
-
-	return 0;
-}
-
-static int atmel_spi_resume(struct device *dev)
-{
-	struct spi_master *master = dev_get_drvdata(dev);
-	struct atmel_spi *as = spi_master_get_devdata(master);
-	int ret;
-
-	ret = clk_prepare_enable(as->clk);
-	if (ret)
-		return ret;
-
-	atmel_spi_init(as);
-
-	clk_disable_unprepare(as->clk);
-
-	if (!pm_runtime_suspended(dev)) {
-		ret = atmel_spi_runtime_resume(dev);
-		if (ret)
-			return ret;
-	}
-
-	/* Start the queue running */
-	ret = spi_master_resume(master);
-	if (ret)
-		dev_err(dev, "problem starting queue (%d)\n", ret);
-
-	return ret;
-}
-#endif
-
-static const struct dev_pm_ops atmel_spi_pm_ops = {
-	SET_SYSTEM_SLEEP_PM_OPS(atmel_spi_suspend, atmel_spi_resume)
-	SET_RUNTIME_PM_OPS(atmel_spi_runtime_suspend,
-			   atmel_spi_runtime_resume, NULL)
-};
-#define ATMEL_SPI_PM_OPS	(&atmel_spi_pm_ops)
-#else
-#define ATMEL_SPI_PM_OPS	NULL
-#endif
-
-#if defined(CONFIG_OF)
-static const struct of_device_id atmel_spi_dt_ids[] = {
-	{ .compatible = "atmel,at91rm9200-spi" },
-	{ /* sentinel */ }
-};
-
-MODULE_DEVICE_TABLE(of, atmel_spi_dt_ids);
-#endif
-
-static struct platform_driver atmel_spi_driver = {
-	.driver		= {
-		.name	= "atmel_spi",
-		.pm	= ATMEL_SPI_PM_OPS,
-		.of_match_table	= of_match_ptr(atmel_spi_dt_ids),
-	},
-	.probe		= atmel_spi_probe,
-	.remove		= atmel_spi_remove,
-};
-module_platform_driver(atmel_spi_driver);
-
-MODULE_DESCRIPTION("Atmel AT32/AT91 SPI Controller driver");
-MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
-MODULE_LICENSE("GPL");
-MODULE_ALIAS("platform:atmel_spi");