RE: [PATCH v7 3/9] spi: Add a driver for the Freescale/NXP QuadSPI controller
From: Yogesh Narayan Gaur
Date: Fri Dec 07 2018 - 00:46:51 EST
Hi Frieder,
> -----Original Message-----
> From: Schrempf Frieder [mailto:frieder.schrempf@xxxxxxxxxx]
> Sent: Tuesday, December 4, 2018 7:45 PM
> To: linux-mtd@xxxxxxxxxxxxxxxxxxx; boris.brezillon@xxxxxxxxxxx; linux-
> spi@xxxxxxxxxxxxxxx; Marek Vasut <marek.vasut@xxxxxxxxx>; Mark Brown
> <broonie@xxxxxxxxxx>; Han Xu <han.xu@xxxxxxx>
> Cc: dwmw2@xxxxxxxxxxxxx; computersforpeace@xxxxxxxxx; richard@xxxxxx;
> miquel.raynal@xxxxxxxxxxx; David Wolfe <david.wolfe@xxxxxxx>; Fabio
> Estevam <fabio.estevam@xxxxxxx>; Prabhakar Kushwaha
> <prabhakar.kushwaha@xxxxxxx>; Yogesh Narayan Gaur
> <yogeshnarayan.gaur@xxxxxxx>; shawnguo@xxxxxxxxxx; Schrempf Frieder
> <frieder.schrempf@xxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx
> Subject: [PATCH v7 3/9] spi: Add a driver for the Freescale/NXP QuadSPI
> controller
>
> From: Frieder Schrempf <frieder.schrempf@xxxxxxxxxx>
>
> 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 | 966 ++++++++++++++++++++++++++++++++++++++
> 5 files changed, 978 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..f0a3400
> --- /dev/null
> +++ b/drivers/spi/spi-fsl-qspi.c
> @@ -0,0 +1,966 @@
> +// 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;
> +
> + 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);
> +
reg is being used as an un-initialized variable, didn't it needs to be initialized with some proper value?
> + return readl_poll_timeout(base, reg, !(reg & mask), delay_us,
> + timeout_us);
> +}
> +
--
Regards
Yogesh Gaur.
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