Re: [PATCH v6 3/9] spi: Add a driver for the Freescale/NXP QuadSPI controller

[Schrempf Frieder <frieder.schrempf@xxxxxxxxxx>]

On 27.11.18 11:24, Schrempf Frieder wrote:
> This driver is derived from the SPI NOR driver at
> mtd/spi-nor/fsl-quadspi.c. It uses the new SPI memory interface
> of the SPI framework to issue flash memory operations to up to
> four connected flash chips (2 buses with 2 CS each).
> 
> The controller does not support generic SPI messages.
> 
> This patch also disables the build of the "old" driver and reuses
> its Kconfig option CONFIG_SPI_FSL_QUADSPI to replace it.
> 
> Signed-off-by: Frieder Schrempf <frieder.schrempf@xxxxxxxxxx>
> ---
>   drivers/mtd/spi-nor/Kconfig  |   9 -
>   drivers/mtd/spi-nor/Makefile |   1 -
>   drivers/spi/Kconfig          |  11 +
>   drivers/spi/Makefile         |   1 +
>   drivers/spi/spi-fsl-qspi.c   | 967 ++++++++++++++++++++++++++++++++++++++
>   5 files changed, 979 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/mtd/spi-nor/Kconfig b/drivers/mtd/spi-nor/Kconfig
> index 6cc9c92..d1ca307 100644
> --- a/drivers/mtd/spi-nor/Kconfig
> +++ b/drivers/mtd/spi-nor/Kconfig
> @@ -59,15 +59,6 @@ config SPI_CADENCE_QUADSPI
>   	  device with a Cadence QSPI controller and want to access the
>   	  Flash as an MTD device.
>   
> -config SPI_FSL_QUADSPI
> -	tristate "Freescale Quad SPI controller"
> -	depends on ARCH_MXC || SOC_LS1021A || ARCH_LAYERSCAPE || COMPILE_TEST
> -	depends on HAS_IOMEM
> -	help
> -	  This enables support for the Quad SPI controller in master mode.
> -	  This controller does not support generic SPI. It only supports
> -	  SPI NOR.
> -
>   config SPI_HISI_SFC
>   	tristate "Hisilicon SPI-NOR Flash Controller(SFC)"
>   	depends on ARCH_HISI || COMPILE_TEST
> diff --git a/drivers/mtd/spi-nor/Makefile b/drivers/mtd/spi-nor/Makefile
> index f4c61d2..3f160c2e3 100644
> --- a/drivers/mtd/spi-nor/Makefile
> +++ b/drivers/mtd/spi-nor/Makefile
> @@ -3,7 +3,6 @@ obj-$(CONFIG_MTD_SPI_NOR)	+= spi-nor.o
>   obj-$(CONFIG_SPI_ASPEED_SMC)	+= aspeed-smc.o
>   obj-$(CONFIG_SPI_ATMEL_QUADSPI)	+= atmel-quadspi.o
>   obj-$(CONFIG_SPI_CADENCE_QUADSPI)	+= cadence-quadspi.o
> -obj-$(CONFIG_SPI_FSL_QUADSPI)	+= fsl-quadspi.o
>   obj-$(CONFIG_SPI_HISI_SFC)	+= hisi-sfc.o
>   obj-$(CONFIG_MTD_MT81xx_NOR)    += mtk-quadspi.o
>   obj-$(CONFIG_SPI_NXP_SPIFI)	+= nxp-spifi.o
> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> index 7d3a5c9..8c84186 100644
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
> @@ -259,6 +259,17 @@ config SPI_FSL_LPSPI
>   	help
>   	  This enables Freescale i.MX LPSPI controllers in master mode.
>   
> +config SPI_FSL_QUADSPI
> +	tristate "Freescale QSPI controller"
> +	depends on ARCH_MXC || SOC_LS1021A || ARCH_LAYERSCAPE || COMPILE_TEST
> +	depends on HAS_IOMEM
> +	help
> +	  This enables support for the Quad SPI controller in master mode.
> +	  Up to four flash chips can be connected on two buses with two
> +	  chipselects each.
> +	  This controller does not support generic SPI messages. It only
> +	  supports the high-level SPI memory interface.
> +
>   config SPI_GPIO
>   	tristate "GPIO-based bitbanging SPI Master"
>   	depends on GPIOLIB || COMPILE_TEST
> diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
> index 3575205..5377e61 100644
> --- a/drivers/spi/Makefile
> +++ b/drivers/spi/Makefile
> @@ -44,6 +44,7 @@ obj-$(CONFIG_SPI_FSL_DSPI)		+= spi-fsl-dspi.o
>   obj-$(CONFIG_SPI_FSL_LIB)		+= spi-fsl-lib.o
>   obj-$(CONFIG_SPI_FSL_ESPI)		+= spi-fsl-espi.o
>   obj-$(CONFIG_SPI_FSL_LPSPI)		+= spi-fsl-lpspi.o
> +obj-$(CONFIG_SPI_FSL_QUADSPI)		+= spi-fsl-qspi.o
>   obj-$(CONFIG_SPI_FSL_SPI)		+= spi-fsl-spi.o
>   obj-$(CONFIG_SPI_GPIO)			+= spi-gpio.o
>   obj-$(CONFIG_SPI_IMG_SPFI)		+= spi-img-spfi.o
> diff --git a/drivers/spi/spi-fsl-qspi.c b/drivers/spi/spi-fsl-qspi.c
> new file mode 100644
> index 0000000..b2d4237
> --- /dev/null
> +++ b/drivers/spi/spi-fsl-qspi.c
> @@ -0,0 +1,967 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +
> +/*
> + * Freescale QuadSPI driver.
> + *
> + * Copyright (C) 2013 Freescale Semiconductor, Inc.
> + * Copyright (C) 2018 Bootlin
> + * Copyright (C) 2018 exceet electronics GmbH
> + * Copyright (C) 2018 Kontron Electronics GmbH
> + *
> + * Transition to SPI MEM interface:
> + * Authors:
> + *     Boris Brezillion <boris.brezillon@xxxxxxxxxxx>
> + *     Frieder Schrempf <frieder.schrempf@xxxxxxxxxx>
> + *     Yogesh Gaur <yogeshnarayan.gaur@xxxxxxx>
> + *     Suresh Gupta <suresh.gupta@xxxxxxx>
> + *
> + * Based on the original fsl-quadspi.c spi-nor driver:
> + * Author: Freescale Semiconductor, Inc.
> + *
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/clk.h>
> +#include <linux/completion.h>
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/errno.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/iopoll.h>
> +#include <linux/jiffies.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_qos.h>
> +#include <linux/sizes.h>
> +
> +#include <linux/spi/spi.h>
> +#include <linux/spi/spi-mem.h>
> +
> +/*
> + * The driver only uses one single LUT entry, that is updated on
> + * each call of exec_op(). Index 0 is preset at boot with a basic
> + * read operation, so let's use the last entry (15).
> + */
> +#define	SEQID_LUT			15
> +
> +/* Registers used by the driver */
> +#define QUADSPI_MCR			0x00
> +#define QUADSPI_MCR_RESERVED_MASK	GENMASK(19, 16)
> +#define QUADSPI_MCR_MDIS_MASK		BIT(14)
> +#define QUADSPI_MCR_CLR_TXF_MASK	BIT(11)
> +#define QUADSPI_MCR_CLR_RXF_MASK	BIT(10)
> +#define QUADSPI_MCR_DDR_EN_MASK		BIT(7)
> +#define QUADSPI_MCR_END_CFG_MASK	GENMASK(3, 2)
> +#define QUADSPI_MCR_SWRSTHD_MASK	BIT(1)
> +#define QUADSPI_MCR_SWRSTSD_MASK	BIT(0)
> +
> +#define QUADSPI_IPCR			0x08
> +#define QUADSPI_IPCR_SEQID(x)		((x) << 24)
> +
> +#define QUADSPI_BUF3CR			0x1c
> +#define QUADSPI_BUF3CR_ALLMST_MASK	BIT(31)
> +#define QUADSPI_BUF3CR_ADATSZ(x)	((x) << 8)
> +#define QUADSPI_BUF3CR_ADATSZ_MASK	GENMASK(15, 8)
> +
> +#define QUADSPI_BFGENCR			0x20
> +#define QUADSPI_BFGENCR_SEQID(x)	((x) << 12)
> +
> +#define QUADSPI_BUF0IND			0x30
> +#define QUADSPI_BUF1IND			0x34
> +#define QUADSPI_BUF2IND			0x38
> +#define QUADSPI_SFAR			0x100
> +
> +#define QUADSPI_SMPR			0x108
> +#define QUADSPI_SMPR_DDRSMP_MASK	GENMASK(18, 16)
> +#define QUADSPI_SMPR_FSDLY_MASK		BIT(6)
> +#define QUADSPI_SMPR_FSPHS_MASK		BIT(5)
> +#define QUADSPI_SMPR_HSENA_MASK		BIT(0)
> +
> +#define QUADSPI_RBCT			0x110
> +#define QUADSPI_RBCT_WMRK_MASK		GENMASK(4, 0)
> +#define QUADSPI_RBCT_RXBRD_USEIPS	BIT(8)
> +
> +#define QUADSPI_TBDR			0x154
> +
> +#define QUADSPI_SR			0x15c
> +#define QUADSPI_SR_IP_ACC_MASK		BIT(1)
> +#define QUADSPI_SR_AHB_ACC_MASK		BIT(2)
> +
> +#define QUADSPI_FR			0x160
> +#define QUADSPI_FR_TFF_MASK		BIT(0)
> +
> +#define QUADSPI_SPTRCLR			0x16c
> +#define QUADSPI_SPTRCLR_IPPTRC		BIT(8)
> +#define QUADSPI_SPTRCLR_BFPTRC		BIT(0)
> +
> +#define QUADSPI_SFA1AD			0x180
> +#define QUADSPI_SFA2AD			0x184
> +#define QUADSPI_SFB1AD			0x188
> +#define QUADSPI_SFB2AD			0x18c
> +#define QUADSPI_RBDR(x)			(0x200 + ((x) * 4))
> +
> +#define QUADSPI_LUTKEY			0x300
> +#define QUADSPI_LUTKEY_VALUE		0x5AF05AF0
> +
> +#define QUADSPI_LCKCR			0x304
> +#define QUADSPI_LCKER_LOCK		BIT(0)
> +#define QUADSPI_LCKER_UNLOCK		BIT(1)
> +
> +#define QUADSPI_RSER			0x164
> +#define QUADSPI_RSER_TFIE		BIT(0)
> +
> +#define QUADSPI_LUT_BASE		0x310
> +#define QUADSPI_LUT_OFFSET		(SEQID_LUT * 4 * 4)
> +#define QUADSPI_LUT_REG(idx) \
> +	(QUADSPI_LUT_BASE + QUADSPI_LUT_OFFSET + (idx) * 4)
> +
> +/* Instruction set for the LUT register */
> +#define LUT_STOP		0
> +#define LUT_CMD			1
> +#define LUT_ADDR		2
> +#define LUT_DUMMY		3
> +#define LUT_MODE		4
> +#define LUT_MODE2		5
> +#define LUT_MODE4		6
> +#define LUT_FSL_READ		7
> +#define LUT_FSL_WRITE		8
> +#define LUT_JMP_ON_CS		9
> +#define LUT_ADDR_DDR		10
> +#define LUT_MODE_DDR		11
> +#define LUT_MODE2_DDR		12
> +#define LUT_MODE4_DDR		13
> +#define LUT_FSL_READ_DDR	14
> +#define LUT_FSL_WRITE_DDR	15
> +#define LUT_DATA_LEARN		16
> +
> +/*
> + * The PAD definitions for LUT register.
> + *
> + * The pad stands for the number of IO lines [0:3].
> + * For example, the quad read needs four IO lines,
> + * so you should use LUT_PAD(4).
> + */
> +#define LUT_PAD(x) (fls(x) - 1)
> +
> +/*
> + * Macro for constructing the LUT entries with the following
> + * register layout:
> + *
> + *  ---------------------------------------------------
> + *  | INSTR1 | PAD1 | OPRND1 | INSTR0 | PAD0 | OPRND0 |
> + *  ---------------------------------------------------
> + */
> +#define LUT_DEF(idx, ins, pad, opr)					\
> +	((((ins) << 10) | ((pad) << 8) | (opr)) << (((idx) % 2) * 16))
> +
> +/* Controller needs driver to swap endianness */
> +#define QUADSPI_QUIRK_SWAP_ENDIAN	BIT(0)
> +
> +/* Controller needs 4x internal clock */
> +#define QUADSPI_QUIRK_4X_INT_CLK	BIT(1)
> +
> +/*
> + * TKT253890, the controller needs the driver to fill the txfifo with
> + * 16 bytes at least to trigger a data transfer, even though the extra
> + * data won't be transferred.
> + */
> +#define QUADSPI_QUIRK_TKT253890		BIT(2)
> +
> +/* TKT245618, the controller cannot wake up from wait mode */
> +#define QUADSPI_QUIRK_TKT245618		BIT(3)
> +
> +/*
> + * Controller adds QSPI_AMBA_BASE (base address of the mapped memory)
> + * internally. No need to add it when setting SFXXAD and SFAR registers
> + */
> +#define QUADSPI_QUIRK_BASE_INTERNAL	BIT(4)
> +
> +struct fsl_qspi_devtype_data {
> +	unsigned int rxfifo;
> +	unsigned int txfifo;
> +	unsigned int ahb_buf_size;
> +	unsigned int quirks;
> +	bool little_endian;
> +};
> +
> +static const struct fsl_qspi_devtype_data vybrid_data = {
> +	.rxfifo = SZ_128,
> +	.txfifo = SZ_64,
> +	.ahb_buf_size = SZ_1K,
> +	.quirks = QUADSPI_QUIRK_SWAP_ENDIAN,
> +	.little_endian = true,
> +};
> +
> +static const struct fsl_qspi_devtype_data imx6sx_data = {
> +	.rxfifo = SZ_128,
> +	.txfifo = SZ_512,
> +	.ahb_buf_size = SZ_1K,
> +	.quirks = QUADSPI_QUIRK_4X_INT_CLK | QUADSPI_QUIRK_TKT245618,
> +	.little_endian = true,
> +};
> +
> +static const struct fsl_qspi_devtype_data imx7d_data = {
> +	.rxfifo = SZ_512,
> +	.txfifo = SZ_512,
> +	.ahb_buf_size = SZ_1K,
> +	.quirks = QUADSPI_QUIRK_TKT253890 | QUADSPI_QUIRK_4X_INT_CLK,
> +	.little_endian = true,
> +};
> +
> +static const struct fsl_qspi_devtype_data imx6ul_data = {
> +	.rxfifo = SZ_128,
> +	.txfifo = SZ_512,
> +	.ahb_buf_size = SZ_1K,
> +	.quirks = QUADSPI_QUIRK_TKT253890 | QUADSPI_QUIRK_4X_INT_CLK,
> +	.little_endian = true,
> +};
> +
> +static const struct fsl_qspi_devtype_data ls1021a_data = {
> +	.rxfifo = SZ_128,
> +	.txfifo = SZ_64,
> +	.ahb_buf_size = SZ_1K,
> +	.quirks = 0,
> +	.little_endian = false,
> +};
> +
> +static const struct fsl_qspi_devtype_data ls2080a_data = {
> +	.rxfifo = SZ_128,
> +	.txfifo = SZ_64,
> +	.ahb_buf_size = SZ_1K,
> +	.quirks = QUADSPI_QUIRK_TKT253890 | QUADSPI_QUIRK_BASE_INTERNAL,
> +	.little_endian = true,
> +};
> +
> +struct fsl_qspi {
> +	void __iomem *iobase;
> +	void __iomem *ahb_addr;
> +	u32 memmap_phy;
> +	struct clk *clk, *clk_en;
> +	struct device *dev;
> +	struct completion c;
> +	const struct fsl_qspi_devtype_data *devtype_data;
> +	struct mutex lock;
> +	struct pm_qos_request pm_qos_req;
> +	int selected;
> +};
> +
> +static inline int needs_swap_endian(struct fsl_qspi *q)
> +{
> +	return q->devtype_data->quirks & QUADSPI_QUIRK_SWAP_ENDIAN;
> +}
> +
> +static inline int needs_4x_clock(struct fsl_qspi *q)
> +{
> +	return q->devtype_data->quirks & QUADSPI_QUIRK_4X_INT_CLK;
> +}
> +
> +static inline int needs_fill_txfifo(struct fsl_qspi *q)
> +{
> +	return q->devtype_data->quirks & QUADSPI_QUIRK_TKT253890;
> +}
> +
> +static inline int needs_wakeup_wait_mode(struct fsl_qspi *q)
> +{
> +	return q->devtype_data->quirks & QUADSPI_QUIRK_TKT245618;
> +}
> +
> +static inline int needs_amba_base_offset(struct fsl_qspi *q)
> +{
> +	return !(q->devtype_data->quirks & QUADSPI_QUIRK_BASE_INTERNAL);
> +}
> +
> +/*
> + * An IC bug makes it necessary to rearrange the 32-bit data.
> + * Later chips, such as IMX6SLX, have fixed this bug.
> + */
> +static inline u32 fsl_qspi_endian_xchg(struct fsl_qspi *q, u32 a)
> +{
> +	return needs_swap_endian(q) ? __swab32(a) : a;
> +}
> +
> +/*
> + * R/W functions for big- or little-endian registers:
> + * The QSPI controller's endianness is independent of
> + * the CPU core's endianness. So far, although the CPU
> + * core is little-endian the QSPI controller can use
> + * big-endian or little-endian.
> + */
> +static void qspi_writel(struct fsl_qspi *q, u32 val, void __iomem *addr)
> +{
> +	if (q->devtype_data->little_endian)
> +		iowrite32(val, addr);
> +	else
> +		iowrite32be(val, addr);
> +}
> +
> +static u32 qspi_readl(struct fsl_qspi *q, void __iomem *addr)
> +{
> +	if (q->devtype_data->little_endian)
> +		return ioread32(addr);
> +
> +	return ioread32be(addr);
> +}
> +
> +static irqreturn_t fsl_qspi_irq_handler(int irq, void *dev_id)
> +{
> +	struct fsl_qspi *q = dev_id;
> +	u32 reg;
> +
> +	/* clear interrupt */
> +	reg = qspi_readl(q, q->iobase + QUADSPI_FR);
> +	qspi_writel(q, reg, q->iobase + QUADSPI_FR);
> +
> +	if (reg & QUADSPI_FR_TFF_MASK)
> +		complete(&q->c);
> +
> +	dev_dbg(q->dev, "QUADSPI_FR : 0x%.8x:0x%.8x\n", 0, reg);
> +	return IRQ_HANDLED;
> +}
> +
> +static int fsl_qspi_check_buswidth(struct fsl_qspi *q, u8 width)
> +{
> +	switch (width) {
> +	case 1:
> +	case 2:
> +	case 4:
> +		return 0;
> +	}
> +
> +	return -ENOTSUPP;
> +}
> +
> +static bool fsl_qspi_supports_op(struct spi_mem *mem,
> +				 const struct spi_mem_op *op)
> +{
> +	struct fsl_qspi *q = spi_controller_get_devdata(mem->spi->master);
> +	int ret;
> +
> +	ret = fsl_qspi_check_buswidth(q, op->cmd.buswidth);
> +
> +	if (op->addr.nbytes)
> +		ret |= fsl_qspi_check_buswidth(q, op->addr.buswidth);
> +
> +	if (op->dummy.nbytes)
> +		ret |= fsl_qspi_check_buswidth(q, op->dummy.buswidth);
> +
> +	if (op->data.nbytes)
> +		ret |= fsl_qspi_check_buswidth(q, op->data.buswidth);
> +
> +	if (ret)
> +		return false;
> +
> +	/*
> +	 * The number of instructions needed for the op, needs
> +	 * to fit into a single LUT entry.
> +	 */
> +	if (op->addr.nbytes +
> +	   (op->dummy.nbytes ? 1:0) +
> +	   (op->data.nbytes ? 1:0) > 6)
> +		return false;
> +
> +	/* Max 64 dummy clock cycles supported */
> +	if (op->dummy.nbytes &&
> +	    (op->dummy.nbytes * 8 / op->dummy.buswidth > 64))
> +		return false;
> +
> +	/* Max data length, check controller limits and alignment */
> +	if (op->data.dir == SPI_MEM_DATA_IN &&
> +	    (op->data.nbytes > q->devtype_data->ahb_buf_size ||
> +	     (op->data.nbytes > q->devtype_data->rxfifo - 4 &&
> +	      !IS_ALIGNED(op->data.nbytes, 8))))
> +		return false;
> +
> +	if (op->data.dir == SPI_MEM_DATA_OUT &&
> +	    op->data.nbytes > q->devtype_data->txfifo)
> +		return false;
> +
> +	return true;
> +}
> +
> +static void fsl_qspi_prepare_lut(struct fsl_qspi *q,
> +				 const struct spi_mem_op *op)
> +{
> +	void __iomem *base = q->iobase;
> +	u32 lutval[4] = {};
> +	int lutidx = 1, i;
> +
> +	lutval[0] |= LUT_DEF(0, LUT_CMD, LUT_PAD(op->cmd.buswidth),
> +			     op->cmd.opcode);
> +
> +	/*
> +	 * For some unknown reason, using LUT_ADDR doesn't work in some
> +	 * cases (at least with only one byte long addresses), so
> +	 * let's use LUT_MODE to write the address bytes one by one
> +	 */
> +	for (i = 0; i < op->addr.nbytes; i++) {
> +		u8 addrbyte = op->addr.val >> (8 * (op->addr.nbytes - i - 1));
> +
> +		lutval[lutidx / 2] |= LUT_DEF(lutidx, LUT_MODE,
> +					      LUT_PAD(op->addr.buswidth),
> +					      addrbyte);
> +		lutidx++;
> +	}
> +
> +	if (op->dummy.nbytes) {
> +		lutval[lutidx / 2] |= LUT_DEF(lutidx, LUT_DUMMY,
> +					      LUT_PAD(op->dummy.buswidth),
> +					      op->dummy.nbytes * 8 /
> +					      op->dummy.buswidth);
> +		lutidx++;
> +	}
> +
> +	if (op->data.nbytes) {
> +		lutval[lutidx / 2] |= LUT_DEF(lutidx,
> +					      op->data.dir == SPI_MEM_DATA_IN ?
> +					      LUT_FSL_READ : LUT_FSL_WRITE,
> +					      LUT_PAD(op->data.buswidth),
> +					      0);
> +		lutidx++;
> +	}
> +
> +	lutval[lutidx / 2] |= LUT_DEF(lutidx, LUT_STOP, 0, 0);
> +
> +	/* unlock LUT */
> +	qspi_writel(q, QUADSPI_LUTKEY_VALUE, q->iobase + QUADSPI_LUTKEY);
> +	qspi_writel(q, QUADSPI_LCKER_UNLOCK, q->iobase + QUADSPI_LCKCR);
> +
> +	/* fill LUT */
> +	for (i = 0; i < ARRAY_SIZE(lutval); i++)
> +		qspi_writel(q, lutval[i], base + QUADSPI_LUT_REG(i));
> +
> +	/* lock LUT */
> +	qspi_writel(q, QUADSPI_LUTKEY_VALUE, q->iobase + QUADSPI_LUTKEY);
> +	qspi_writel(q, QUADSPI_LCKER_LOCK, q->iobase + QUADSPI_LCKCR);
> +}
> +
> +static int fsl_qspi_clk_prep_enable(struct fsl_qspi *q)
> +{
> +	int ret;
> +
> +	ret = clk_prepare_enable(q->clk_en);
> +	if (ret)
> +		return ret;
> +
> +	ret = clk_prepare_enable(q->clk);
> +	if (ret) {
> +		clk_disable_unprepare(q->clk_en);
> +		return ret;
> +	}
> +
> +	if (needs_wakeup_wait_mode(q))
> +		pm_qos_add_request(&q->pm_qos_req, PM_QOS_CPU_DMA_LATENCY, 0);
> +
> +	return 0;
> +}
> +
> +static void fsl_qspi_clk_disable_unprep(struct fsl_qspi *q)
> +{
> +	if (needs_wakeup_wait_mode(q))
> +		pm_qos_remove_request(&q->pm_qos_req);
> +
> +	clk_disable_unprepare(q->clk);
> +	clk_disable_unprepare(q->clk_en);
> +}
> +
> +/*
> + * If we have changed the content of the flash by writing or erasing, or if we
> + * read from flash with a different offset into the page buffer, we need to
> + * invalidate the AHB buffer. If we do not do so, we may read out the wrong
> + * data. The spec tells us reset the AHB domain and Serial Flash domain at
> + * the same time.
> + */
> +static void fsl_qspi_invalidate(struct fsl_qspi *q)
> +{
> +	u32 reg;
> +
> +	reg = qspi_readl(q, q->iobase + QUADSPI_MCR);
> +	reg |= QUADSPI_MCR_SWRSTHD_MASK | QUADSPI_MCR_SWRSTSD_MASK;
> +	qspi_writel(q, reg, q->iobase + QUADSPI_MCR);
> +
> +	/*
> +	 * The minimum delay : 1 AHB + 2 SFCK clocks.
> +	 * Delay 1 us is enough.
> +	 */
> +	udelay(1);
> +
> +	reg &= ~(QUADSPI_MCR_SWRSTHD_MASK | QUADSPI_MCR_SWRSTSD_MASK);
> +	qspi_writel(q, reg, q->iobase + QUADSPI_MCR);
> +}
> +
> +static void fsl_qspi_select_mem(struct fsl_qspi *q, struct spi_device *spi)
> +{
> +	unsigned long rate = spi->max_speed_hz;
> +	int ret, i;
> +	u32 map_addr;

Forgot to drop some unused vars here. I will remove them in the next 
version.

> +
> +	if (q->selected == spi->chip_select)
> +		return;
> +
> +	if (needs_4x_clock(q))
> +		rate *= 4;
> +
> +	fsl_qspi_clk_disable_unprep(q);
> +
> +	ret = clk_set_rate(q->clk, rate);
> +	if (ret)
> +		return;
> +
> +	ret = fsl_qspi_clk_prep_enable(q);
> +	if (ret)
> +		return;
> +
> +	q->selected = spi->chip_select;
> +
> +	fsl_qspi_invalidate(q);
> +}
> +
> +static void fsl_qspi_read_ahb(struct fsl_qspi *q, const struct spi_mem_op *op)
> +{
> +	memcpy_fromio(op->data.buf.in,
> +		      q->ahb_addr + q->selected * q->devtype_data->ahb_buf_size,
> +		      op->data.nbytes);
> +}
> +
> +static void fsl_qspi_fill_txfifo(struct fsl_qspi *q,
> +				 const struct spi_mem_op *op)
> +{
> +	void __iomem *base = q->iobase;
> +	int i;
> +	u32 val;
> +
> +	for (i = 0; i < ALIGN_DOWN(op->data.nbytes, 4); i += 4) {
> +		memcpy(&val, op->data.buf.out + i, 4);
> +		val = fsl_qspi_endian_xchg(q, val);
> +		qspi_writel(q, val, base + QUADSPI_TBDR);
> +	}
> +
> +	if (i < op->data.nbytes) {
> +		memcpy(&val, op->data.buf.out + i, op->data.nbytes - i);
> +		val = fsl_qspi_endian_xchg(q, val);
> +		qspi_writel(q, val, base + QUADSPI_TBDR);
> +	}
> +
> +	if (needs_fill_txfifo(q)) {
> +		for (i = op->data.nbytes; i < 16; i += 4)
> +			qspi_writel(q, 0, base + QUADSPI_TBDR);
> +	}
> +}
> +
> +static void fsl_qspi_read_rxfifo(struct fsl_qspi *q,
> +			  const struct spi_mem_op *op)
> +{
> +	void __iomem *base = q->iobase;
> +	int i;
> +	u8 *buf = op->data.buf.in;
> +	u32 val;
> +
> +	for (i = 0; i < ALIGN_DOWN(op->data.nbytes, 4); i += 4) {
> +		val = qspi_readl(q, base + QUADSPI_RBDR(i / 4));
> +		val = fsl_qspi_endian_xchg(q, val);
> +		memcpy(buf + i, &val, 4);
> +	}
> +
> +	if (i < op->data.nbytes) {
> +		val = qspi_readl(q, base + QUADSPI_RBDR(i / 4));
> +		val = fsl_qspi_endian_xchg(q, val);
> +		memcpy(buf + i, &val, op->data.nbytes - i);
> +	}
> +}
> +
> +static int fsl_qspi_do_op(struct fsl_qspi *q, const struct spi_mem_op *op)
> +{
> +	void __iomem *base = q->iobase;
> +	int err = 0;
> +
> +	init_completion(&q->c);
> +
> +	/*
> +	 * Always start the sequence at the same index since we update
> +	 * the LUT at each exec_op() call. And also specify the DATA
> +	 * length, since it's has not been specified in the LUT.
> +	 */
> +	qspi_writel(q, op->data.nbytes | QUADSPI_IPCR_SEQID(SEQID_LUT),
> +		    base + QUADSPI_IPCR);
> +
> +	/* Wait for the interrupt. */
> +	if (!wait_for_completion_timeout(&q->c, msecs_to_jiffies(1000)))
> +		err = -ETIMEDOUT;
> +
> +	if (!err && op->data.nbytes && op->data.dir == SPI_MEM_DATA_IN)
> +		fsl_qspi_read_rxfifo(q, op);
> +
> +	return err;
> +}
> +
> +static int fsl_qspi_readl_poll_tout(struct fsl_qspi *q, void __iomem *base,
> +				    u32 mask, u32 delay_us, u32 timeout_us)
> +{
> +	u32 reg;
> +
> +	if (!q->devtype_data->little_endian)
> +		mask = (u32)cpu_to_be32(mask);
> +
> +	return readl_poll_timeout(base, reg, !(reg & mask), delay_us,
> +				  timeout_us);
> +}
> +
> +static int fsl_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
> +{
> +	struct fsl_qspi *q = spi_controller_get_devdata(mem->spi->master);
> +	void __iomem *base = q->iobase;
> +	u32 addr_offset = 0;
> +	int err = 0;
> +
> +	mutex_lock(&q->lock);
> +
> +	/* wait for the controller being ready */
> +	fsl_qspi_readl_poll_tout(q, base + QUADSPI_SR, (QUADSPI_SR_IP_ACC_MASK |
> +				 QUADSPI_SR_AHB_ACC_MASK), 10, 1000);
> +
> +	fsl_qspi_select_mem(q, mem->spi);
> +
> +	if (needs_amba_base_offset(q))
> +		addr_offset = q->memmap_phy;
> +
> +	qspi_writel(q,
> +		    q->selected * q->devtype_data->ahb_buf_size + addr_offset,
> +		    base + QUADSPI_SFAR);
> +
> +	qspi_writel(q, qspi_readl(q, base + QUADSPI_MCR) |
> +		    QUADSPI_MCR_CLR_RXF_MASK | QUADSPI_MCR_CLR_TXF_MASK,
> +		    base + QUADSPI_MCR);
> +
> +	qspi_writel(q, QUADSPI_SPTRCLR_BFPTRC | QUADSPI_SPTRCLR_IPPTRC,
> +		    base + QUADSPI_SPTRCLR);
> +
> +	fsl_qspi_prepare_lut(q, op);
> +
> +	/*
> +	 * If we have large chunks of data, we read them through the AHB bus
> +	 * by accessing the mapped memory. In all other cases we use
> +	 * IP commands to access the flash.
> +	 */
> +	if (op->data.nbytes > (q->devtype_data->rxfifo - 4) &&
> +	    op->data.dir == SPI_MEM_DATA_IN) {
> +		fsl_qspi_read_ahb(q, op);
> +	} else {
> +		qspi_writel(q, QUADSPI_RBCT_WMRK_MASK |
> +			    QUADSPI_RBCT_RXBRD_USEIPS, base + QUADSPI_RBCT);
> +
> +		if (op->data.nbytes && op->data.dir == SPI_MEM_DATA_OUT)
> +			fsl_qspi_fill_txfifo(q, op);
> +
> +		err = fsl_qspi_do_op(q, op);
> +	}
> +
> +	/* Invalidate the data in the AHB buffer. */
> +	fsl_qspi_invalidate(q);
> +
> +	mutex_unlock(&q->lock);
> +
> +	return err;
> +}
> +
> +static int fsl_qspi_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
> +{
> +	struct fsl_qspi *q = spi_controller_get_devdata(mem->spi->master);
> +
> +	if (op->data.dir == SPI_MEM_DATA_OUT) {
> +		if (op->data.nbytes > q->devtype_data->txfifo)
> +			op->data.nbytes = q->devtype_data->txfifo;
> +	} else {
> +		if (op->data.nbytes > q->devtype_data->ahb_buf_size)
> +			op->data.nbytes = q->devtype_data->ahb_buf_size;
> +		else if (op->data.nbytes > (q->devtype_data->rxfifo - 4))
> +			op->data.nbytes = ALIGN_DOWN(op->data.nbytes, 8);
> +	}
> +
> +	return 0;
> +}
> +
> +static int fsl_qspi_default_setup(struct fsl_qspi *q)
> +{
> +	void __iomem *base = q->iobase;
> +	u32 reg, addr_offset = 0;
> +	int ret;
> +
> +	/* disable and unprepare clock to avoid glitch pass to controller */
> +	fsl_qspi_clk_disable_unprep(q);
> +
> +	/* the default frequency, we will change it later if necessary. */
> +	ret = clk_set_rate(q->clk, 66000000);
> +	if (ret)
> +		return ret;
> +
> +	ret = fsl_qspi_clk_prep_enable(q);
> +	if (ret)
> +		return ret;
> +
> +	/* Reset the module */
> +	qspi_writel(q, QUADSPI_MCR_SWRSTSD_MASK | QUADSPI_MCR_SWRSTHD_MASK,
> +		    base + QUADSPI_MCR);
> +	udelay(1);
> +
> +	/* Disable the module */
> +	qspi_writel(q, QUADSPI_MCR_MDIS_MASK | QUADSPI_MCR_RESERVED_MASK,
> +		    base + QUADSPI_MCR);
> +
> +	reg = qspi_readl(q, base + QUADSPI_SMPR);
> +	qspi_writel(q, reg & ~(QUADSPI_SMPR_FSDLY_MASK
> +			| QUADSPI_SMPR_FSPHS_MASK
> +			| QUADSPI_SMPR_HSENA_MASK
> +			| QUADSPI_SMPR_DDRSMP_MASK), base + QUADSPI_SMPR);
> +
> +	/* We only use the buffer3 for AHB read */
> +	qspi_writel(q, 0, base + QUADSPI_BUF0IND);
> +	qspi_writel(q, 0, base + QUADSPI_BUF1IND);
> +	qspi_writel(q, 0, base + QUADSPI_BUF2IND);
> +
> +	qspi_writel(q, QUADSPI_BFGENCR_SEQID(SEQID_LUT),
> +		    q->iobase + QUADSPI_BFGENCR);
> +	qspi_writel(q, QUADSPI_RBCT_WMRK_MASK, base + QUADSPI_RBCT);
> +	qspi_writel(q, QUADSPI_BUF3CR_ALLMST_MASK |
> +		    QUADSPI_BUF3CR_ADATSZ(q->devtype_data->ahb_buf_size / 8),
> +		    base + QUADSPI_BUF3CR);
> +
> +	if (needs_amba_base_offset(q))
> +		addr_offset = q->memmap_phy;
> +
> +	/*
> +	 * In HW there can be a maximum of four chips on two buses with
> +	 * two chip selects on each bus. We use four chip selects in SW
> +	 * to differentiate between the four chips.
> +	 * We use ahb_buf_size for each chip and set SFA1AD, SFA2AD, SFB1AD,
> +	 * SFB2AD accordingly.
> +	 */
> +	qspi_writel(q, q->devtype_data->ahb_buf_size + addr_offset,
> +		    base + QUADSPI_SFA1AD);
> +	qspi_writel(q, q->devtype_data->ahb_buf_size * 2 + addr_offset,
> +		    base + QUADSPI_SFA2AD);
> +	qspi_writel(q, q->devtype_data->ahb_buf_size * 3 + addr_offset,
> +		    base + QUADSPI_SFB1AD);
> +	qspi_writel(q, q->devtype_data->ahb_buf_size * 4 + addr_offset,
> +		    base + QUADSPI_SFB2AD);
> +
> +	q->selected = -1;
> +
> +	/* Enable the module */
> +	qspi_writel(q, QUADSPI_MCR_RESERVED_MASK | QUADSPI_MCR_END_CFG_MASK,
> +		    base + QUADSPI_MCR);
> +
> +	/* clear all interrupt status */
> +	qspi_writel(q, 0xffffffff, q->iobase + QUADSPI_FR);
> +
> +	/* enable the interrupt */
> +	qspi_writel(q, QUADSPI_RSER_TFIE, q->iobase + QUADSPI_RSER);
> +
> +	return 0;
> +}
> +
> +static const char *fsl_qspi_get_name(struct spi_mem *mem)
> +{
> +	struct fsl_qspi *q = spi_controller_get_devdata(mem->spi->master);
> +	struct device *dev = &mem->spi->dev;
> +	const char *name;
> +
> +	/*
> +	 * In order to keep mtdparts compatible with the old MTD driver at
> +	 * mtd/spi-nor/fsl-quadspi.c, we set a custom name derived from the
> +	 * platform_device of the controller.
> +	 */
> +	if (of_get_available_child_count(q->dev->of_node) == 1)
> +		return dev_name(q->dev);
> +
> +	name = devm_kasprintf(dev, GFP_KERNEL,
> +			      "%s-%d", dev_name(q->dev),
> +			      mem->spi->chip_select);
> +
> +	if (!name) {
> +		dev_err(dev, "failed to get memory for custom flash name\n");
> +		return ERR_PTR(-ENOMEM);
> +	}
> +
> +	return name;
> +}
> +
> +static const struct spi_controller_mem_ops fsl_qspi_mem_ops = {
> +	.adjust_op_size = fsl_qspi_adjust_op_size,
> +	.supports_op = fsl_qspi_supports_op,
> +	.exec_op = fsl_qspi_exec_op,
> +	.get_name = fsl_qspi_get_name,
> +};
> +
> +static int fsl_qspi_probe(struct platform_device *pdev)
> +{
> +	struct spi_controller *ctlr;
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +	struct resource *res;
> +	struct fsl_qspi *q;
> +	int ret;
> +
> +	ctlr = spi_alloc_master(&pdev->dev, sizeof(*q));
> +	if (!ctlr)
> +		return -ENOMEM;
> +
> +	ctlr->mode_bits = SPI_RX_DUAL | SPI_RX_QUAD |
> +			  SPI_TX_DUAL | SPI_TX_QUAD;
> +
> +	q = spi_controller_get_devdata(ctlr);
> +	q->dev = dev;
> +	q->devtype_data = of_device_get_match_data(dev);
> +	if (!q->devtype_data) {
> +		ret = -ENODEV;
> +		goto err_put_ctrl;
> +	}
> +
> +	platform_set_drvdata(pdev, q);
> +
> +	/* find the resources */
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "QuadSPI");
> +	q->iobase = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(q->iobase)) {
> +		ret = PTR_ERR(q->iobase);
> +		goto err_put_ctrl;
> +	}
> +
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> +					"QuadSPI-memory");
> +	q->ahb_addr = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(q->ahb_addr)) {
> +		ret = PTR_ERR(q->ahb_addr);
> +		goto err_put_ctrl;
> +	}
> +
> +	q->memmap_phy = res->start;
> +
> +	/* find the clocks */
> +	q->clk_en = devm_clk_get(dev, "qspi_en");
> +	if (IS_ERR(q->clk_en)) {
> +		ret = PTR_ERR(q->clk_en);
> +		goto err_put_ctrl;
> +	}
> +
> +	q->clk = devm_clk_get(dev, "qspi");
> +	if (IS_ERR(q->clk)) {
> +		ret = PTR_ERR(q->clk);
> +		goto err_put_ctrl;
> +	}
> +
> +	ret = fsl_qspi_clk_prep_enable(q);
> +	if (ret) {
> +		dev_err(dev, "can not enable the clock\n");
> +		goto err_put_ctrl;
> +	}
> +
> +	/* find the irq */
> +	ret = platform_get_irq(pdev, 0);
> +	if (ret < 0) {
> +		dev_err(dev, "failed to get the irq: %d\n", ret);
> +		goto err_disable_clk;
> +	}
> +
> +	ret = devm_request_irq(dev, ret,
> +			fsl_qspi_irq_handler, 0, pdev->name, q);
> +	if (ret) {
> +		dev_err(dev, "failed to request irq: %d\n", ret);
> +		goto err_disable_clk;
> +	}
> +
> +	mutex_init(&q->lock);
> +
> +	ctlr->bus_num = -1;
> +	ctlr->num_chipselect = 4;
> +	ctlr->mem_ops = &fsl_qspi_mem_ops;
> +
> +	fsl_qspi_default_setup(q);
> +
> +	ctlr->dev.of_node = np;
> +
> +	ret = spi_register_controller(ctlr);
> +	if (ret)
> +		goto err_destroy_mutex;
> +
> +	return 0;
> +
> +err_destroy_mutex:
> +	mutex_destroy(&q->lock);
> +
> +err_disable_clk:
> +	fsl_qspi_clk_disable_unprep(q);
> +
> +err_put_ctrl:
> +	spi_controller_put(ctlr);
> +
> +	dev_err(dev, "Freescale QuadSPI probe failed\n");
> +	return ret;
> +}
> +
> +static int fsl_qspi_remove(struct platform_device *pdev)
> +{
> +	struct fsl_qspi *q = platform_get_drvdata(pdev);
> +
> +	/* disable the hardware */
> +	qspi_writel(q, QUADSPI_MCR_MDIS_MASK, q->iobase + QUADSPI_MCR);
> +	qspi_writel(q, 0x0, q->iobase + QUADSPI_RSER);
> +
> +	fsl_qspi_clk_disable_unprep(q);
> +
> +	mutex_destroy(&q->lock);
> +
> +	return 0;
> +}
> +
> +static int fsl_qspi_suspend(struct device *dev)
> +{
> +	return 0;
> +}
> +
> +static int fsl_qspi_resume(struct device *dev)
> +{
> +	struct fsl_qspi *q = dev_get_drvdata(dev);
> +
> +	fsl_qspi_default_setup(q);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id fsl_qspi_dt_ids[] = {
> +	{ .compatible = "fsl,vf610-qspi", .data = &vybrid_data, },
> +	{ .compatible = "fsl,imx6sx-qspi", .data = &imx6sx_data, },
> +	{ .compatible = "fsl,imx7d-qspi", .data = &imx7d_data, },
> +	{ .compatible = "fsl,imx6ul-qspi", .data = &imx6ul_data, },
> +	{ .compatible = "fsl,ls1021a-qspi", .data = &ls1021a_data, },
> +	{ .compatible = "fsl,ls2080a-qspi", .data = &ls2080a_data, },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, fsl_qspi_dt_ids);
> +
> +static const struct dev_pm_ops fsl_qspi_pm_ops = {
> +	.suspend	= fsl_qspi_suspend,
> +	.resume		= fsl_qspi_resume,
> +};
> +
> +static struct platform_driver fsl_qspi_driver = {
> +	.driver = {
> +		.name	= "fsl-quadspi",
> +		.of_match_table = fsl_qspi_dt_ids,
> +		.pm =   &fsl_qspi_pm_ops,
> +	},
> +	.probe          = fsl_qspi_probe,
> +	.remove		= fsl_qspi_remove,
> +};
> +module_platform_driver(fsl_qspi_driver);
> +
> +MODULE_DESCRIPTION("Freescale QuadSPI Controller Driver");
> +MODULE_AUTHOR("Freescale Semiconductor Inc.");
> +MODULE_AUTHOR("Boris Brezillion <boris.brezillon@xxxxxxxxxxx>");
> +MODULE_AUTHOR("Frieder Schrempf <frieder.schrempf@xxxxxxxxxx>");
> +MODULE_AUTHOR("Yogesh Gaur <yogeshnarayan.gaur@xxxxxxx>");
> +MODULE_AUTHOR("Suresh Gupta <suresh.gupta@xxxxxxx>");
> +MODULE_LICENSE("GPL v2");
>