Hi,

> -----Original Message-----
> From: Yogesh Narayan Gaur
> Sent: Tuesday, November 13, 2018 1:53 PM
> To: 'Frieder Schrempf' <frieder.schre...@kontron.de>; linux-
> m...@lists.infradead.org; boris.brezil...@bootlin.com; linux-
> s...@vger.kernel.org
> Cc: dw...@infradead.org; computersforpe...@gmail.com;
> marek.va...@gmail.com; rich...@nod.at; miquel.ray...@bootlin.com;
> broo...@kernel.org; David Wolfe <david.wo...@nxp.com>; Fabio Estevam
> <fabio.este...@nxp.com>; Prabhakar Kushwaha
> <prabhakar.kushw...@nxp.com>; Han Xu <han...@nxp.com>;
> shawn...@kernel.org; Frieder Schrempf <frieder.schre...@exceet.de>; linux-
> ker...@vger.kernel.org
> Subject: RE: [PATCH v4 01/10] spi: Add a driver for the Freescale/NXP QuadSPI
> controller
> 
> Hi,
> 
> > -----Original Message-----
> > From: Frieder Schrempf [mailto:frieder.schre...@kontron.de]
> > Sent: Wednesday, November 7, 2018 8:13 PM
> > To: linux-...@lists.infradead.org; boris.brezil...@bootlin.com; linux-
> > s...@vger.kernel.org
> > Cc: dw...@infradead.org; computersforpe...@gmail.com;
> > marek.va...@gmail.com; rich...@nod.at; miquel.ray...@bootlin.com;
> > broo...@kernel.org; David Wolfe <david.wo...@nxp.com>; Fabio Estevam
> > <fabio.este...@nxp.com>; Prabhakar Kushwaha
> > <prabhakar.kushw...@nxp.com>; Yogesh Narayan Gaur
> > <yogeshnarayan.g...@nxp.com>; Han Xu <han...@nxp.com>;
> > shawn...@kernel.org; Frieder Schrempf <frieder.schre...@exceet.de>;
> > linux- ker...@vger.kernel.org
> > Subject: [PATCH v4 01/10] spi: Add a driver for the Freescale/NXP
> > QuadSPI controller
> >
> > From: Frieder Schrempf <frieder.schre...@exceet.de>
> >
> > 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.
> >
> > Signed-off-by: Frieder Schrempf <frieder.schre...@exceet.de>
> > ---
> >  drivers/spi/Kconfig        |  11 +
> >  drivers/spi/Makefile       |   1 +
> >  drivers/spi/spi-fsl-qspi.c | 948
> > ++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 960 insertions(+)
> >
> > diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index
> > 7d3a5c9..52e2298
> > 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_QSPI
> > +   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..833b9e7
> > 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-$(CONFIG_SPI_FSL_QSPI)         += spi-fsl-qspi.o
> >  obj-$(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..a43cfe8
> > --- /dev/null
> > +++ b/drivers/spi/spi-fsl-qspi.c
> > @@ -0,0 +1,948 @@
> > +// 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:
> > + * Author:
> > + *     Boris Brezillion <boris.brezil...@bootlin.com>
> > + *     Frieder Schrempf <frieder.schre...@kontron.de>
> > + *     Yogesh Gaur <yogeshnarayan.g...@nxp.com>
> > + *     Suresh Gupta <suresh.gu...@nxp.com>
> > + *
> > + * 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)
> > +
> > +enum fsl_qspi_devtype {
> > +   FSL_QUADSPI_VYBRID,
> > +   FSL_QUADSPI_IMX6SX,
> > +   FSL_QUADSPI_IMX7D,
> > +   FSL_QUADSPI_IMX6UL,
> > +   FSL_QUADSPI_LS1021A,
> > +   FSL_QUADSPI_LS2080A,
> > +};
> > +
> We can go away with this enum
> 
> > +struct fsl_qspi_devtype_data {
> > +   enum fsl_qspi_devtype devtype;
> > +   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 = {
> > +   .devtype = FSL_QUADSPI_VYBRID,
> > +   .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 = {
> > +   .devtype = FSL_QUADSPI_IMX6SX,
> > +   .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 = {
> > +   .devtype = FSL_QUADSPI_IMX7D,
> > +   .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 = {
> > +   .devtype = FSL_QUADSPI_IMX6UL,
> > +   .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 = {
> > +   .devtype = FSL_QUADSPI_LS1021A,
> > +   .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 = {
> > +   .devtype = FSL_QUADSPI_LS2080A,
> > +   .rxfifo = SZ_128,
> > +   .txfifo = SZ_64,
> > +   .ahb_buf_size = SZ_1K,
> > +   .quirks = QUADSPI_QUIRK_TKT253890,
> > +   .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;
> > +   u8 seq;
> > +   void (*write)(u32 val, void __iomem *addr);
> > +   u32 (*read)(void __iomem *addr);

We can go away with these read and write function pointer.

--
Regards
Yogesh Gaur
> > +};
> > +
> > +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; }
> > +
> > +/*
> > + * 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);
> > +}
> > +
> > +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;
> > +
> > +   if (q->selected == spi->chip_select)
> > +           return;
> > +
> > +   /*
> > +    * 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 the SFA1AD, SFA2AD, SFB1AD, SFB2AD registers to select
> > +    * the chip we want to access.
> > +    */
> > +   for (i = 0; i < 4; i++) {
> > +           if (i < spi->chip_select)
> > +                   map_addr = q->memmap_phy;
> > +           else
> > +                   map_addr = q->memmap_phy +
> > +                              2 * q->devtype_data->ahb_buf_size;
> > +
> > +           qspi_writel(q, map_addr, q->iobase + QUADSPI_SFA1AD + (i *
> > 4));
> > +   }
> > +
> > +   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;
> > +}
> > +
> > +static void fsl_qspi_read_ahb(struct fsl_qspi *q, const struct
> > +spi_mem_op *op) {
> > +   /*
> > +    * We want to avoid needing to invalidate the cache by issueing
> > +    * a reset to the AHB and Serial Flash domain, as this needs
> > +    * time. So we change the address on each read to trigger an
> > +    * actual read operation on the flash. The actual address for
> > +    * the flash memory is set by programming the LUT.
> > +    */
> As discussed previously, please go away with this hack and use AHB bus
> invalidation method with smaller timeout value.
> 
> I would start doing validation of this patch series from next version onward. 
> As
> you have mentioned in other mail discussion about issue in the break condition
> for function  fsl_qspi_readl_poll_tout().
> 
> --
> Regards
> Yogesh Gaur
> 
> > +   memcpy_fromio(op->data.buf.in,
> > +                 q->ahb_addr +
> > +                 (((q->seq & (1 << q->selected)) == 0 ? 0:1) *
> > +                  q->devtype_data->ahb_buf_size),
> > +                 op->data.nbytes);
> > +
> > +   q->seq ^= 1 << q->selected;
> > +}
> > +
> > +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;
> > +   int err = 0;
> > +
> > +   mutex_lock(&q->lock);
> > +
> > +   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);
> > +
> > +   qspi_writel(q, q->memmap_phy, 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);
> > +   }
> > +
> > +   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;
> > +   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);
> > +
> > +   q->selected = -1;
> > +   q->seq = 0;
> > +
> > +   /* 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.brezil...@bootlin.com>"); MODULE_AUTHOR("Frieder
> > +Schrempf <frieder.schre...@kontron.de>"); MODULE_AUTHOR("Yogesh
> Gaur
> > +<yogeshnarayan.g...@nxp.com>"); MODULE_AUTHOR("Suresh Gupta
> > +<suresh.gu...@nxp.com>"); MODULE_LICENSE("GPL v2");
> > --
> > 2.7.4

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