[PATCH V5 2/2] mtd: spi-nor: Add driver for Cadence Quad SPI Flash Controller.

vikasm vikas.manocha at st.com
Fri Jul 24 17:02:01 PDT 2015


Hi Graham,

On 07/24/2015 10:17 AM, Graham Moore wrote:
> Signed-off-by: Graham Moore <grmoore at opensource.altera.com>
> ---
> V2: use NULL instead of modalias in spi_nor_scan call
> V3: Use existing property is-decoded-cs instead of creating duplicate.
> V4: Support Micron quad mode by snooping command stream for EVCR command
> and subsequently configuring Cadence controller for quad mode.
> V5: Clean up sparse and smatch complaints.  Remove snooping of Micron
> quad mode.  Add comment on XIP mode bit and dummy clock cycles.  Set
> up SRAM partition at 1:1 during init.
> ---
>  arch/arm/boot/dts/socfpga.dtsi               |    1 +
>  arch/arm/boot/dts/socfpga_cyclone5_socdk.dts |    1 -
>  drivers/mtd/spi-nor/Kconfig                  |    6 +
>  drivers/mtd/spi-nor/Makefile                 |    1 +
>  drivers/mtd/spi-nor/cadence-quadspi.c        | 1261 ++++++++++++++++++++++++++
>  5 files changed, 1269 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/mtd/spi-nor/cadence-quadspi.c
>
> diff --git a/arch/arm/boot/dts/socfpga.dtsi b/arch/arm/boot/dts/socfpga.dtsi
> index c71a705..e9ecdce 100644
> --- a/arch/arm/boot/dts/socfpga.dtsi
> +++ b/arch/arm/boot/dts/socfpga.dtsi
> @@ -695,6 +695,7 @@
>                         is-decoded-cs = <1>;
>                         fifo-depth = <128>;
>                         status = "disabled";
> +                       m25p,fast-read;

This patch is not applicable to l2-mtd master or linus master repo, might need to rebase it.
   
>                 };
>
>                 /* Local timer */
> diff --git a/arch/arm/boot/dts/socfpga_cyclone5_socdk.dts b/arch/arm/boot/dts/socfpga_cyclone5_socdk.dts
> index 9886728..1792c43 100644
> --- a/arch/arm/boot/dts/socfpga_cyclone5_socdk.dts
> +++ b/arch/arm/boot/dts/socfpga_cyclone5_socdk.dts
> @@ -98,7 +98,6 @@
>                 compatible = "n25q00", "n25q512a", "n25q512ax3";
>                 reg = <0>;
>                 spi-max-frequency = <100000000>;
> -               m25p,fast-read;
>
>                 cdns,page-size = <256>;
>                 cdns,block-size = <16>;
> diff --git a/drivers/mtd/spi-nor/Kconfig b/drivers/mtd/spi-nor/Kconfig
> index 64a4f0e..9485481 100644
> --- a/drivers/mtd/spi-nor/Kconfig
> +++ b/drivers/mtd/spi-nor/Kconfig
> @@ -28,4 +28,10 @@ config SPI_FSL_QUADSPI
>           This enables support for the Quad SPI controller in master mode.
>           We only connect the NOR to this controller now.
>
> +config SPI_CADENCE_QUADSPI
> +       tristate "Cadence Quad SPI controller"
> +       depends on ARCH_SOCFPGA
> +       help
> +         This enables support for the Cadence Quad SPI controller and NOR flash.
> +
>  endif # MTD_SPI_NOR
> diff --git a/drivers/mtd/spi-nor/Makefile b/drivers/mtd/spi-nor/Makefile
> index 6a7ce14..372628c 100644
> --- a/drivers/mtd/spi-nor/Makefile
> +++ b/drivers/mtd/spi-nor/Makefile
> @@ -1,2 +1,3 @@
>  obj-$(CONFIG_MTD_SPI_NOR)      += spi-nor.o
> +obj-$(CONFIG_SPI_CADENCE_QUADSPI)      += cadence-quadspi.o
>  obj-$(CONFIG_SPI_FSL_QUADSPI)  += fsl-quadspi.o
> diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c
> new file mode 100644
> index 0000000..4881db5
> --- /dev/null
> +++ b/drivers/mtd/spi-nor/cadence-quadspi.c
> @@ -0,0 +1,1261 @@
> +/*
> + * Driver for Cadence QSPI Controller
> + *
> + * Copyright Altera Corporation (C) 2012-2014. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program.  If not, see <http://www.gnu.org/licenses/>.
> + */
> +#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/jiffies.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/mtd/mtd.h>
> +#include <linux/mtd/partitions.h>
> +#include <linux/mtd/spi-nor.h>
> +#include <linux/of_device.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/sched.h>
> +#include <linux/spi/spi.h>
> +#include <linux/timer.h>
> +
> +#define CQSPI_NAME                     "cadence-qspi"

replace space with tabs.

> +#define CQSPI_MAX_CHIPSELECT           16

replace space with tabs.

> +
> +struct cqspi_flash_pdata {
> +       struct mtd_info mtd;

replace space with tabs at all relevant code locations in the file, most of the code is using spaces instead of tabs.

> +       struct spi_nor nor;
> +       u32 clk_rate;
> +       unsigned int read_delay;
> +       unsigned int tshsl_ns;
> +       unsigned int tsd2d_ns;
> +       unsigned int tchsh_ns;
> +       unsigned int tslch_ns;
> +};
> +
> +struct cqspi_st {
> +       struct platform_device *pdev;
> +
> +       struct clk *clk;
> +       unsigned int sclk;
> +
> +       void __iomem *iobase;
> +       void __iomem *ahb_base;
> +       struct completion transfer_complete;
> +       unsigned int irq_mask;
> +       int current_cs;
> +       unsigned int ahb_phy_addr;
> +       unsigned int master_ref_clk_hz;
> +       u32 is_decoded_cs;
> +       unsigned int fifo_depth;
> +       struct cqspi_flash_pdata f_pdata[CQSPI_MAX_CHIPSELECT];
> +};
> +
> +/* Operation timeout value */
> +#define CQSPI_TIMEOUT_MS                       500
> +#define CQSPI_READ_TIMEOUT_MS                  10
> +#define CQSPI_POLL_IDLE_RETRY                  3
> +
> +#define CQSPI_FIFO_WIDTH                       4

FIFO width could be 4 or 8 etc depending on the SOC, it would be better to get it from device.
You can refer to u-boot code for the same.

> +
> +#define CQSPI_REG_SRAM_RESV_WORDS              2
> +#define CQSPI_REG_SRAM_PARTITION_WR            1
> +#define CQSPI_REG_SRAM_THRESHOLD_BYTES         50
> +
> +/* Instruction type */
> +#define CQSPI_INST_TYPE_SINGLE                 0
> +#define CQSPI_INST_TYPE_DUAL                   1
> +#define CQSPI_INST_TYPE_QUAD                   2
> +
> +#define CQSPI_DUMMY_CLKS_MAX                   31
> +
> +#define CQSPI_STIG_DATA_LEN_MAX                        8
> +
> +#define CQSPI_INDIRECTTRIGGER_ADDR_MASK                0xFFFFF

Mask value of 0xFFFFF is specific to socfpga platform.
Please refer to u-boot patchset for same discussion.

> +
> +/* Register map */
> +#define CQSPI_REG_CONFIG                       0x00
> +#define CQSPI_REG_CONFIG_ENABLE_MASK           BIT(0)
> +#define CQSPI_REG_CONFIG_DECODE_MASK           BIT(9)
> +#define CQSPI_REG_CONFIG_CHIPSELECT_LSB                10
> +#define CQSPI_REG_CONFIG_DMA_MASK              BIT(15)
> +#define CQSPI_REG_CONFIG_BAUD_LSB              19
> +#define CQSPI_REG_CONFIG_IDLE_LSB              31
> +#define CQSPI_REG_CONFIG_CHIPSELECT_MASK       0xF
> +#define CQSPI_REG_CONFIG_BAUD_MASK             0xF
> +
> +#define CQSPI_REG_RD_INSTR                     0x04
> +#define CQSPI_REG_RD_INSTR_OPCODE_LSB          0
> +#define CQSPI_REG_RD_INSTR_TYPE_INSTR_LSB      8
> +#define CQSPI_REG_RD_INSTR_TYPE_ADDR_LSB       12
> +#define CQSPI_REG_RD_INSTR_TYPE_DATA_LSB       16
> +#define CQSPI_REG_RD_INSTR_MODE_EN_LSB         20
> +#define CQSPI_REG_RD_INSTR_DUMMY_LSB           24
> +#define CQSPI_REG_RD_INSTR_TYPE_INSTR_MASK     0x3
> +#define CQSPI_REG_RD_INSTR_TYPE_ADDR_MASK      0x3
> +#define CQSPI_REG_RD_INSTR_TYPE_DATA_MASK      0x3
> +#define CQSPI_REG_RD_INSTR_DUMMY_MASK          0x1F
> +
> +#define CQSPI_REG_WR_INSTR                     0x08
> +#define CQSPI_REG_WR_INSTR_OPCODE_LSB          0
> +#define CQSPI_REG_WR_INSTR_TYPE_ADDR_LSB       12
> +#define CQSPI_REG_WR_INSTR_TYPE_DATA_LSB       16
> +
> +#define CQSPI_REG_DELAY                                0x0C
> +#define CQSPI_REG_DELAY_TSLCH_LSB              0
> +#define CQSPI_REG_DELAY_TCHSH_LSB              8
> +#define CQSPI_REG_DELAY_TSD2D_LSB              16
> +#define CQSPI_REG_DELAY_TSHSL_LSB              24
> +#define CQSPI_REG_DELAY_TSLCH_MASK             0xFF
> +#define CQSPI_REG_DELAY_TCHSH_MASK             0xFF
> +#define CQSPI_REG_DELAY_TSD2D_MASK             0xFF
> +#define CQSPI_REG_DELAY_TSHSL_MASK             0xFF
> +
> +#define CQSPI_REG_READCAPTURE                  0x10
> +#define CQSPI_REG_READCAPTURE_BYPASS_LSB       0
> +#define CQSPI_REG_READCAPTURE_DELAY_LSB                1
> +#define CQSPI_REG_READCAPTURE_DELAY_MASK       0xF
> +
> +#define CQSPI_REG_SIZE                         0x14
> +#define CQSPI_REG_SIZE_ADDRESS_LSB             0
> +#define CQSPI_REG_SIZE_PAGE_LSB                        4
> +#define CQSPI_REG_SIZE_BLOCK_LSB               16
> +#define CQSPI_REG_SIZE_ADDRESS_MASK            0xF
> +#define CQSPI_REG_SIZE_PAGE_MASK               0xFFF
> +#define CQSPI_REG_SIZE_BLOCK_MASK              0x3F
> +
> +#define CQSPI_REG_SRAMPARTITION                        0x18
> +#define CQSPI_REG_INDIRECTTRIGGER              0x1C
> +
> +#define CQSPI_REG_DMA                          0x20
> +#define CQSPI_REG_DMA_SINGLE_LSB               0
> +#define CQSPI_REG_DMA_BURST_LSB                        8
> +#define CQSPI_REG_DMA_SINGLE_MASK              0xFF
> +#define CQSPI_REG_DMA_BURST_MASK               0xFF
> +
> +#define CQSPI_REG_REMAP                                0x24
> +#define CQSPI_REG_MODE_BIT                     0x28
> +
> +#define CQSPI_REG_SDRAMLEVEL                   0x2C
> +#define CQSPI_REG_SDRAMLEVEL_RD_LSB            0
> +#define CQSPI_REG_SDRAMLEVEL_WR_LSB            16
> +#define CQSPI_REG_SDRAMLEVEL_RD_MASK           0xFFFF
> +#define CQSPI_REG_SDRAMLEVEL_WR_MASK           0xFFFF
> +
> +#define CQSPI_REG_IRQSTATUS                    0x40
> +#define CQSPI_REG_IRQMASK                      0x44
> +
> +#define CQSPI_REG_INDIRECTRD                   0x60
> +#define CQSPI_REG_INDIRECTRD_START_MASK                BIT(0)
> +#define CQSPI_REG_INDIRECTRD_CANCEL_MASK       BIT(1)
> +#define CQSPI_REG_INDIRECTRD_DONE_MASK         BIT(5)
> +
> +#define CQSPI_REG_INDIRECTRDWATERMARK          0x64
> +#define CQSPI_REG_INDIRECTRDSTARTADDR          0x68
> +#define CQSPI_REG_INDIRECTRDBYTES              0x6C
> +
> +#define CQSPI_REG_CMDCTRL                      0x90
> +#define CQSPI_REG_CMDCTRL_EXECUTE_MASK         BIT(0)
> +#define CQSPI_REG_CMDCTRL_INPROGRESS_MASK      BIT(1)
> +#define CQSPI_REG_CMDCTRL_WR_BYTES_LSB         12
> +#define CQSPI_REG_CMDCTRL_WR_EN_LSB            15
> +#define CQSPI_REG_CMDCTRL_ADD_BYTES_LSB                16
> +#define CQSPI_REG_CMDCTRL_ADDR_EN_LSB          19
> +#define CQSPI_REG_CMDCTRL_RD_BYTES_LSB         20
> +#define CQSPI_REG_CMDCTRL_RD_EN_LSB            23
> +#define CQSPI_REG_CMDCTRL_OPCODE_LSB           24
> +#define CQSPI_REG_CMDCTRL_WR_BYTES_MASK                0x7
> +#define CQSPI_REG_CMDCTRL_ADD_BYTES_MASK       0x3
> +#define CQSPI_REG_CMDCTRL_RD_BYTES_MASK                0x7
> +
> +#define CQSPI_REG_INDIRECTWR                   0x70
> +#define CQSPI_REG_INDIRECTWR_START_MASK                BIT(0)
> +#define CQSPI_REG_INDIRECTWR_CANCEL_MASK       BIT(1)
> +#define CQSPI_REG_INDIRECTWR_DONE_MASK         BIT(5)
> +
> +#define CQSPI_REG_INDIRECTWRWATERMARK          0x74
> +#define CQSPI_REG_INDIRECTWRSTARTADDR          0x78
> +#define CQSPI_REG_INDIRECTWRBYTES              0x7C
> +
> +#define CQSPI_REG_CMDADDRESS                   0x94
> +#define CQSPI_REG_CMDREADDATALOWER             0xA0
> +#define CQSPI_REG_CMDREADDATAUPPER             0xA4
> +#define CQSPI_REG_CMDWRITEDATALOWER            0xA8
> +#define CQSPI_REG_CMDWRITEDATAUPPER            0xAC
> +
> +/* Interrupt status bits */
> +#define CQSPI_REG_IRQ_MODE_ERR                 BIT(0)
> +#define CQSPI_REG_IRQ_UNDERFLOW                        BIT(1)
> +#define CQSPI_REG_IRQ_IND_COMP                 BIT(2)
> +#define CQSPI_REG_IRQ_IND_RD_REJECT            BIT(3)
> +#define CQSPI_REG_IRQ_WR_PROTECTED_ERR         BIT(4)
> +#define CQSPI_REG_IRQ_ILLEGAL_AHB_ERR          BIT(5)
> +#define CQSPI_REG_IRQ_WATERMARK                        BIT(6)
> +#define CQSPI_REG_IRQ_IND_RD_OVERFLOW          BIT(12)
> +
> +#define CQSPI_IRQ_STATUS_ERR           (CQSPI_REG_IRQ_MODE_ERR         | \
> +                                        CQSPI_REG_IRQ_IND_RD_REJECT    | \
> +                                        CQSPI_REG_IRQ_WR_PROTECTED_ERR | \
> +                                        CQSPI_REG_IRQ_ILLEGAL_AHB_ERR)
> +
> +#define CQSPI_IRQ_MASK_RD              (CQSPI_REG_IRQ_WATERMARK        | \
> +                                        CQSPI_REG_IRQ_IND_RD_OVERFLOW  | \
> +                                        CQSPI_REG_IRQ_IND_COMP)
> +
> +#define CQSPI_IRQ_MASK_WR              (CQSPI_REG_IRQ_IND_COMP         | \
> +                                        CQSPI_REG_IRQ_WATERMARK        | \
> +                                        CQSPI_REG_IRQ_UNDERFLOW)
> +
> +#define CQSPI_IRQ_STATUS_MASK          0x1FFFF
> +
> +#define CQSPI_REG_IS_IDLE(base)                                                \
> +               ((readl(base + CQSPI_REG_CONFIG) >>             \
> +                       CQSPI_REG_CONFIG_IDLE_LSB) & 0x1)
> +
> +#define CQSPI_GET_RD_SRAM_LEVEL(reg_base)                              \
> +               (((readl(reg_base + CQSPI_REG_SDRAMLEVEL)) >>   \
> +               CQSPI_REG_SDRAMLEVEL_RD_LSB) & CQSPI_REG_SDRAMLEVEL_RD_MASK)
> +
> +static unsigned int cqspi_init_timeout(unsigned long timeout_in_ms)
> +{
> +       return jiffies + msecs_to_jiffies(timeout_in_ms);
> +}
> +
> +static unsigned int cqspi_check_timeout(unsigned long timeout)
> +{
> +       return time_before(jiffies, timeout);
> +}
> +
> +static void cqspi_fifo_read(void *dest, const void __iomem *src_ahb_addr,
> +                           unsigned int bytes)
> +{
> +       unsigned int temp;
> +       int remaining = bytes;
> +       unsigned int *dest_ptr = (unsigned int *)dest;
> +
> +       while (remaining >= CQSPI_FIFO_WIDTH) {
> +               *dest_ptr = readl(src_ahb_addr);
> +               dest_ptr++;
> +               remaining -= CQSPI_FIFO_WIDTH;

this logic only works when fifo width is 4 with "unsigned int" data of 4 bytes.
It has been corrected in mainline u-boot or in the u-boot patches.

> +       }
> +       if (remaining > 0) {
> +               /* dangling bytes */
> +               temp = readl(src_ahb_addr);
> +               memcpy(dest_ptr, &temp, remaining);
> +       }
> +}
> +
> +static void cqspi_fifo_write(void __iomem *dest_ahb_addr,
> +                            const void *src, unsigned int bytes)
> +{
> +       unsigned int temp;
> +       int remaining = bytes;
> +       unsigned int *src_ptr = (unsigned int *)src;
> +
> +       while (remaining >= CQSPI_FIFO_WIDTH) {
> +               writel(*src_ptr, dest_ahb_addr);
> +               src_ptr++;
> +               remaining -= CQSPI_FIFO_WIDTH;

same here, this logic only works for fifo width of 4.

> +       }
> +       if (remaining > 0) {
> +               /* dangling bytes */
> +               memcpy(&temp, src_ptr, remaining);
> +               writel(temp, dest_ahb_addr);
> +       }
> +}
> +
> +static irqreturn_t cqspi_irq_handler(int this_irq, void *dev)
> +{
> +       struct cqspi_st *cqspi = dev;
> +       unsigned int irq_status;
> +
> +       /* Read interrupt status */
> +       irq_status = readl(cqspi->iobase + CQSPI_REG_IRQSTATUS);
> +
> +       /* Clear interrupt */
> +       writel(irq_status, cqspi->iobase + CQSPI_REG_IRQSTATUS);
> +
> +       if (irq_status & cqspi->irq_mask)
> +               complete(&cqspi->transfer_complete);
> +
> +       return IRQ_HANDLED;
> +}
> +
> +static int cqspi_find_chipselect(struct spi_nor *nor)
> +{
> +       int cs = -1;
> +       struct cqspi_st *cqspi = nor->priv;
> +
> +       for (cs = 0; cs < CQSPI_MAX_CHIPSELECT; cs++)
> +               if (nor == &cqspi->f_pdata[cs].nor)
> +                       break;
> +       return cs;
> +}
> +
> +static unsigned int cqspi_calc_rdreg(struct spi_nor *nor, u8 opcode)
> +{
> +       unsigned int rdreg = 0;
> +       struct cqspi_st *cqspi = nor->priv;
> +       struct cqspi_flash_pdata *f_pdata;
> +
> +       f_pdata = &cqspi->f_pdata[cqspi->current_cs];
> +
> +       if (nor->flash_read == SPI_NOR_QUAD)
> +               rdreg |= (CQSPI_INST_TYPE_QUAD
> +                         << CQSPI_REG_RD_INSTR_TYPE_DATA_LSB);
> +       return rdreg;
> +}
> +
> +static unsigned int cqspi_wait_idle(struct cqspi_st *cqspi)
> +{
> +       void __iomem *reg_base = cqspi->iobase;
> +       unsigned int count = 0;
> +       unsigned timeout;
> +
> +       timeout = cqspi_init_timeout(CQSPI_TIMEOUT_MS);
> +       while (cqspi_check_timeout(timeout)) {
> +               if (CQSPI_REG_IS_IDLE(reg_base)) {
> +                       /*
> +                        * Read few times in succession to ensure it does
> +                        * not transition low again
> +                        */
> +                       count++;
> +                       if (count >= CQSPI_POLL_IDLE_RETRY)
> +                               return 1;
> +               } else {
> +                       count = 0;
> +               }
> +               cpu_relax();
> +       }
> +
> +       /* Timeout, in busy mode. */
> +       dev_err(&cqspi->pdev->dev, "QSPI is still busy after %dms timeout.\n",
> +               CQSPI_TIMEOUT_MS);
> +       return 0;
> +}
> +
> +static int cqspi_exec_flash_cmd(struct cqspi_st *cqspi, unsigned int reg)
> +{
> +       void __iomem *reg_base = cqspi->iobase;
> +       unsigned int timeout;
> +
> +       /* Write the CMDCTRL without start execution. */
> +       writel(reg, reg_base + CQSPI_REG_CMDCTRL);
> +       /* Start execute */
> +       reg |= CQSPI_REG_CMDCTRL_EXECUTE_MASK;
> +       writel(reg, reg_base + CQSPI_REG_CMDCTRL);
> +
> +       /* Polling for completion. */
> +       timeout = cqspi_init_timeout(CQSPI_TIMEOUT_MS);
> +       while (cqspi_check_timeout(timeout)) {
> +               reg = readl(reg_base + CQSPI_REG_CMDCTRL) &
> +                   CQSPI_REG_CMDCTRL_INPROGRESS_MASK;
> +               if (!reg)
> +                       break;
> +       }
> +
> +       if (reg != 0) {
> +               dev_err(&cqspi->pdev->dev, "flash cmd execute time out\n");
> +               return -EIO;
> +       }
> +
> +       /* Polling QSPI idle status. */
> +       if (!cqspi_wait_idle(cqspi))
> +               return -EIO;
> +
> +       return 0;
> +}
> +
> +static int cqspi_command_read(struct spi_nor *nor,
> +                             const u8 *txbuf, unsigned n_tx,
> +                             u8 *rxbuf, unsigned n_rx)
> +{
> +       unsigned int reg;
> +       unsigned int read_len;
> +       int status;
> +       struct cqspi_st *cqspi = nor->priv;
> +       void __iomem *reg_base = cqspi->iobase;
> +       unsigned int rdreg;
> +
> +       if (!n_rx || n_rx > CQSPI_STIG_DATA_LEN_MAX || !rxbuf) {
> +               dev_err(nor->dev,
> +                       "Invalid input argument, len %d rxbuf 0x%08x\n", n_rx,
> +                       (unsigned int)rxbuf);
> +               return -EINVAL;
> +       }
> +
> +       reg = txbuf[0] << CQSPI_REG_CMDCTRL_OPCODE_LSB;
> +
> +       rdreg = cqspi_calc_rdreg(nor, txbuf[0]);
> +       writel(rdreg, reg_base + CQSPI_REG_RD_INSTR);
> +
> +       reg |= (0x1 << CQSPI_REG_CMDCTRL_RD_EN_LSB);
> +
> +       /* 0 means 1 byte. */
> +       reg |= (((n_rx - 1) & CQSPI_REG_CMDCTRL_RD_BYTES_MASK)
> +               << CQSPI_REG_CMDCTRL_RD_BYTES_LSB);
> +       status = cqspi_exec_flash_cmd(cqspi, reg);
> +       if (status != 0)
> +               return status;
> +
> +       reg = readl(reg_base + CQSPI_REG_CMDREADDATALOWER);
> +
> +       /* Put the read value into rx_buf */
> +       read_len = (n_rx > 4) ? 4 : n_rx;
> +       memcpy(rxbuf, &reg, read_len);
> +       rxbuf += read_len;
> +
> +       if (n_rx > 4) {
> +               reg = readl(reg_base + CQSPI_REG_CMDREADDATAUPPER);
> +
> +               read_len = n_rx - read_len;
> +               memcpy(rxbuf, &reg, read_len);
> +       }
> +
> +       return 0;
> +}
> +
> +static int cqspi_command_write(struct spi_nor *nor,
> +                              u8 opcode, const u8 *txbuf, unsigned n_tx)
> +{
> +       unsigned int reg;
> +       unsigned int data;
> +       int ret;
> +       struct cqspi_st *cqspi = nor->priv;
> +       void __iomem *reg_base = cqspi->iobase;
> +
> +       if (n_tx > 4 || (n_tx && !txbuf)) {
> +               dev_err(nor->dev,
> +                       "Invalid input argument, cmdlen %d txbuf 0x%08x\n",
> +                       n_tx, (unsigned int)txbuf);
> +               return -EINVAL;
> +       }
> +
> +       reg = opcode << CQSPI_REG_CMDCTRL_OPCODE_LSB;
> +       if (n_tx) {
> +               reg |= (0x1 << CQSPI_REG_CMDCTRL_WR_EN_LSB);
> +               reg |= ((n_tx - 1) & CQSPI_REG_CMDCTRL_WR_BYTES_MASK)
> +                   << CQSPI_REG_CMDCTRL_WR_BYTES_LSB;
> +               data = 0;
> +               memcpy(&data, txbuf, n_tx);
> +               writel(data, reg_base + CQSPI_REG_CMDWRITEDATALOWER);
> +       }
> +
> +       ret = cqspi_exec_flash_cmd(cqspi, reg);
> +       return ret;
> +}
> +
> +static int cqspi_command_write_addr(struct spi_nor *nor,
> +                                   u8 opcode, unsigned int addr)
> +{
> +       unsigned int reg;
> +       struct cqspi_st *cqspi = nor->priv;
> +       void __iomem *reg_base = cqspi->iobase;
> +
> +       reg = opcode << CQSPI_REG_CMDCTRL_OPCODE_LSB;
> +       reg |= (0x1 << CQSPI_REG_CMDCTRL_ADDR_EN_LSB);
> +       reg |= ((nor->addr_width - 1) & CQSPI_REG_CMDCTRL_ADD_BYTES_MASK)
> +           << CQSPI_REG_CMDCTRL_ADD_BYTES_LSB;
> +
> +       writel(addr, reg_base + CQSPI_REG_CMDADDRESS);
> +
> +       return cqspi_exec_flash_cmd(cqspi, reg);
> +}
> +
> +static int cqspi_indirect_read_setup(struct spi_nor *nor,
> +                                    unsigned int from_addr)
> +{
> +       unsigned int reg;
> +       unsigned int dummy_clk = 0;
> +       struct cqspi_st *cqspi = nor->priv;
> +       void __iomem *reg_base = cqspi->iobase;
> +       unsigned int ahb_phy_addr = cqspi->ahb_phy_addr;
> +
> +       writel((ahb_phy_addr & CQSPI_INDIRECTTRIGGER_ADDR_MASK),
> +              reg_base + CQSPI_REG_INDIRECTTRIGGER);
> +       writel(from_addr, reg_base + CQSPI_REG_INDIRECTRDSTARTADDR);

Base trigger register address (0x1c register) corresponds to the address which
should be put on AHB bus to handle indirect transfer triggered before.
   
To handle indirect transfer we need to issue addresses from (value of 0x1c) to
(value of 0x1c) + 15*4 ("4" corresponds to size of SRAM location).
There are no obstacles in issuing const address just equal to 0x1c. Important
thing to note is that indirect trigger address has nothing in common with your
physical or mapped NOR Flash address.
   
Transfer read/write start addresses should be programmed with the absolute flash address
to be read/written.

> +
> +       reg = nor->read_opcode << CQSPI_REG_RD_INSTR_OPCODE_LSB;
> +       reg |= cqspi_calc_rdreg(nor, nor->read_opcode);
> +
> +       /* Setup dummy clock cycles */
> +#define CQSPI_SUPPORT_XIP_CHIPS
> +#ifdef CQSPI_SUPPORT_XIP_CHIPS
> +       /*
> +        * Set mode bits high to ensure chip doesn't enter XIP.
> +        * This results in an extra 8 dummy clocks so
> +        * we must account for them.
> +        */
> +       writel(0xFF, reg_base + CQSPI_REG_MODE_BIT);
> +       reg |= (1 << CQSPI_REG_RD_INSTR_MODE_EN_LSB);
> +       if (nor->read_dummy >= 8)
> +               dummy_clk = nor->read_dummy - 8;
> +       else
> +               dummy_clk = 0;
> +#else
> +       dummy_clk = nor->read_dummy;
> +#endif
> +       reg |= (dummy_clk & CQSPI_REG_RD_INSTR_DUMMY_MASK)
> +           << CQSPI_REG_RD_INSTR_DUMMY_LSB;
> +
> +       writel(reg, reg_base + CQSPI_REG_RD_INSTR);
> +
> +       /* Set address width */
> +       reg = readl(reg_base + CQSPI_REG_SIZE);
> +       reg &= ~CQSPI_REG_SIZE_ADDRESS_MASK;
> +       reg |= (nor->addr_width - 1);
> +       writel(reg, reg_base + CQSPI_REG_SIZE);
> +       return 0;
> +}
> +
> +static int cqspi_indirect_read_execute(struct spi_nor *nor,
> +                                      u8 *rxbuf, unsigned n_rx)
> +{
> +       int ret = 0;
> +       unsigned int reg = 0;
> +       unsigned int bytes_to_read = 0;
> +       unsigned int timeout;
> +       unsigned int watermark;
> +       struct cqspi_st *cqspi = nor->priv;
> +       void __iomem *reg_base = cqspi->iobase;
> +       void __iomem *ahb_base = cqspi->ahb_base;
> +       int remaining = (int)n_rx;
> +
> +       watermark = cqspi->fifo_depth * CQSPI_FIFO_WIDTH / 2;
> +       writel(watermark, reg_base + CQSPI_REG_INDIRECTRDWATERMARK);
> +       writel(remaining, reg_base + CQSPI_REG_INDIRECTRDBYTES);
> +       writel(cqspi->fifo_depth - CQSPI_REG_SRAM_RESV_WORDS,
> +              reg_base + CQSPI_REG_SRAMPARTITION);

sram partioning is not needed to be changed at every read/write, it should be ok to configure it
in the init like divide half for read & half for write.

> +
> +       /* Clear all interrupts. */
> +       writel(CQSPI_IRQ_STATUS_MASK, reg_base + CQSPI_REG_IRQSTATUS);
> +
> +       cqspi->irq_mask = CQSPI_IRQ_MASK_RD;
> +       writel(cqspi->irq_mask, reg_base + CQSPI_REG_IRQMASK);
> +
> +       reinit_completion(&cqspi->transfer_complete);
> +       writel(CQSPI_REG_INDIRECTRD_START_MASK,
> +              reg_base + CQSPI_REG_INDIRECTRD);
> +
> +       while (remaining > 0) {
> +               ret = wait_for_completion_timeout(&cqspi->transfer_complete,
> +                                                 msecs_to_jiffies
> +                                                 (CQSPI_READ_TIMEOUT_MS));
> +
> +               bytes_to_read = CQSPI_GET_RD_SRAM_LEVEL(reg_base);

Base trigger register address (0x1c register) corresponds to the address which
should be put on AHB bus to handle indirect transfer triggered before.
   
To handle indirect transfer we need to issue addresses from (value of 0x1c) to
(value of 0x1c) + 15*4 ("4" corresponds to size of SRAM location).
There are no obstacles in issuing const address just equal to 0x1c. Important
thing to note is that indirect trigger address has nothing in common with your
physical or mapped NOR Flash address.
   
Transfer read/write start addresses (offset 0x68/0x78)should be programmed with
the absolute flash address to be read/written.


> +
> +               if (!ret && bytes_to_read == 0) {
> +                       dev_err(nor->dev, "Indirect read timeout, no bytes\n");
> +                       ret = -ETIMEDOUT;
> +                       goto failrd;
> +               }
> +
> +               while (bytes_to_read != 0) {
> +                       bytes_to_read *= CQSPI_FIFO_WIDTH;
> +                       bytes_to_read = bytes_to_read > remaining
> +                           ? remaining : bytes_to_read;
> +                       cqspi_fifo_read(rxbuf, ahb_base, bytes_to_read);
> +                       rxbuf += bytes_to_read;
> +                       remaining -= bytes_to_read;
> +                       bytes_to_read = CQSPI_GET_RD_SRAM_LEVEL(reg_base);
> +               }
> +       }
> +
> +       /* Check indirect done status */
> +       timeout = cqspi_init_timeout(CQSPI_TIMEOUT_MS);
> +       while (cqspi_check_timeout(timeout)) {
> +               reg = readl(reg_base + CQSPI_REG_INDIRECTRD);
> +               if (reg & CQSPI_REG_INDIRECTRD_DONE_MASK)
> +                       break;
> +       }
> +
> +       if (!(reg & CQSPI_REG_INDIRECTRD_DONE_MASK)) {
> +               dev_err(nor->dev,
> +                       "Indirect read completion error 0x%08x\n", reg);
> +               ret = -ETIMEDOUT;
> +               goto failrd;
> +       }
> +
> +       /* Disable interrupt */
> +       writel(0, reg_base + CQSPI_REG_IRQMASK);
> +
> +       /* Clear indirect completion status */
> +       writel(CQSPI_REG_INDIRECTRD_DONE_MASK, reg_base + CQSPI_REG_INDIRECTRD);
> +
> +       return 0;
> +
> + failrd:
> +       /* Disable interrupt */
> +       writel(0, reg_base + CQSPI_REG_IRQMASK);
> +
> +       /* Cancel the indirect read */
> +       writel(CQSPI_REG_INDIRECTWR_CANCEL_MASK,
> +              reg_base + CQSPI_REG_INDIRECTRD);
> +       return ret;
> +}
> +
> +static int cqspi_indirect_write_setup(struct spi_nor *nor, unsigned int to_addr)
> +{
> +       unsigned int reg;
> +       struct cqspi_st *cqspi = nor->priv;
> +       void __iomem *reg_base = cqspi->iobase;
> +       unsigned int ahb_phy_addr = cqspi->ahb_phy_addr;
> +
> +       /* Set opcode. */
> +       reg = nor->program_opcode << CQSPI_REG_WR_INSTR_OPCODE_LSB;
> +       writel(reg, reg_base + CQSPI_REG_WR_INSTR);
> +       reg = cqspi_calc_rdreg(nor, nor->program_opcode);
> +       writel(reg, reg_base + CQSPI_REG_RD_INSTR);
> +
> +       writel((ahb_phy_addr & CQSPI_INDIRECTTRIGGER_ADDR_MASK),
> +              reg_base + CQSPI_REG_INDIRECTTRIGGER);
> +       writel(to_addr, reg_base + CQSPI_REG_INDIRECTWRSTARTADDR);
> +
> +       reg = readl(reg_base + CQSPI_REG_SIZE);
> +       reg &= ~CQSPI_REG_SIZE_ADDRESS_MASK;
> +       reg |= (nor->addr_width - 1);
> +       writel(reg, reg_base + CQSPI_REG_SIZE);
> +       return 0;
> +}
> +
> +static int cqspi_indirect_write_execute(struct spi_nor *nor,
> +                                       const u8 *txbuf, unsigned n_tx)
> +{
> +       int ret;
> +       unsigned int timeout;
> +       unsigned int reg = 0;
> +       struct cqspi_st *cqspi = nor->priv;
> +       void __iomem *reg_base = cqspi->iobase;
> +       void __iomem *ahb_base = cqspi->ahb_base;
> +       int remaining = (int)n_tx;
> +       struct cqspi_flash_pdata *f_pdata;
> +       unsigned int page_size;
> +       unsigned int write_bytes;
> +
> +       f_pdata = &cqspi->f_pdata[cqspi->current_cs];
> +       page_size = nor->page_size;
> +
> +       writel(CQSPI_REG_SRAM_THRESHOLD_BYTES, reg_base +
> +              CQSPI_REG_INDIRECTWRWATERMARK);
> +       writel(remaining, reg_base + CQSPI_REG_INDIRECTWRBYTES);
> +       writel(CQSPI_REG_SRAM_PARTITION_WR,
> +              reg_base + CQSPI_REG_SRAMPARTITION);

same comment as of read_execute, better to configure it once in init.

Rgds,
Vikas

> +
> +       /* Clear all interrupts. */
> +       writel(CQSPI_IRQ_STATUS_MASK, reg_base + CQSPI_REG_IRQSTATUS);
> +
> +       cqspi->irq_mask = CQSPI_IRQ_MASK_WR;
> +       writel(cqspi->irq_mask, reg_base + CQSPI_REG_IRQMASK);
> +
> +       reinit_completion(&cqspi->transfer_complete);
> +       writel(CQSPI_REG_INDIRECTWR_START_MASK,
> +              reg_base + CQSPI_REG_INDIRECTWR);
> +
> +       /* Write a page or remaining bytes. */
> +       write_bytes = remaining > page_size ? page_size : remaining;
> +       /* Fill up the data at the beginning */
> +       cqspi_fifo_write(ahb_base, txbuf, write_bytes);
> +       txbuf += write_bytes;
> +       remaining -= write_bytes;
> +
> +       while (remaining > 0) {
> +               ret = wait_for_completion_timeout(&cqspi->transfer_complete,
> +                                                 msecs_to_jiffies
> +                                                 (CQSPI_TIMEOUT_MS));
> +               if (!ret) {
> +                       dev_err(nor->dev, "Indirect write timeout\n");
> +                       ret = -ETIMEDOUT;
> +                       goto failwr;
> +               }
> +
> +               write_bytes = remaining > page_size ? page_size : remaining;
> +               cqspi_fifo_write(ahb_base, txbuf, write_bytes);
> +               txbuf += write_bytes;
> +               remaining -= write_bytes;
> +       }
> +
> +       ret = wait_for_completion_timeout(&cqspi->transfer_complete,
> +                                         msecs_to_jiffies(CQSPI_TIMEOUT_MS));
> +       if (!ret) {
> +               dev_err(nor->dev, "Indirect write timeout\n");
> +               ret = -ETIMEDOUT;
> +               goto failwr;
> +       }
> +
> +       /* Check indirect done status */
> +       timeout = cqspi_init_timeout(CQSPI_TIMEOUT_MS);
> +       while (cqspi_check_timeout(timeout)) {
> +               reg = readl(reg_base + CQSPI_REG_INDIRECTWR);
> +               if (reg & CQSPI_REG_INDIRECTWR_DONE_MASK)
> +                       break;
> +       }
> +
> +       if (!(reg & CQSPI_REG_INDIRECTWR_DONE_MASK)) {
> +               dev_err(nor->dev,
> +                       "Indirect write completion error 0x%08x\n", reg);
> +               ret = -ETIMEDOUT;
> +               goto failwr;
> +       }
> +
> +       /* Disable interrupt. */
> +       writel(0, reg_base + CQSPI_REG_IRQMASK);
> +
> +       /* Clear indirect completion status */
> +       writel(CQSPI_REG_INDIRECTWR_DONE_MASK, reg_base + CQSPI_REG_INDIRECTWR);
> +
> +       cqspi_wait_idle(cqspi);
> +
> +       return 0;
> +
> + failwr:
> +       /* Disable interrupt. */
> +       writel(0, reg_base + CQSPI_REG_IRQMASK);
> +
> +       /* Cancel the indirect write */
> +       writel(CQSPI_REG_INDIRECTWR_CANCEL_MASK,
> +              reg_base + CQSPI_REG_INDIRECTWR);
> +       return ret;
> +}
> +
> +static void cqspi_write(struct spi_nor *nor, loff_t to,
> +                       size_t len, size_t *retlen, const u_char *buf)
> +{
> +       int ret;
> +
> +       ret = cqspi_indirect_write_setup(nor, to);
> +       if (ret == 0) {
> +               ret = cqspi_indirect_write_execute(nor, buf, len);
> +               if (ret == 0)
> +                       *retlen += len;
> +       }
> +}
> +
> +static int cqspi_read(struct spi_nor *nor, loff_t from,
> +                     size_t len, size_t *retlen, u_char *buf)
> +{
> +       int ret;
> +
> +       ret = cqspi_indirect_read_setup(nor, from);
> +       if (ret == 0) {
> +               ret = cqspi_indirect_read_execute(nor, buf, len);
> +               if (ret == 0)
> +                       *retlen += len;
> +       }
> +       return ret;
> +}
> +
> +static int cqspi_erase(struct spi_nor *nor, loff_t offs)
> +{
> +       int ret;
> +
> +       /* Send write enable, then erase commands. */
> +       ret = nor->write_reg(nor, SPINOR_OP_WREN, NULL, 0, 0);
> +       if (ret)
> +               return ret;
> +
> +       /* Set up command buffer. */
> +       ret = cqspi_command_write_addr(nor, nor->erase_opcode, offs);
> +       if (ret)
> +               return ret;
> +
> +       return 0;
> +}
> +
> +static unsigned int calculate_ticks_for_ns(unsigned int ref_clk_hz,
> +                                          unsigned int ns_val)
> +{
> +       unsigned int ticks;
> +
> +       ticks = ref_clk_hz;
> +       ticks /= 1000;
> +       ticks *= ns_val;
> +       ticks += 999999;
> +       ticks /= 1000000;
> +       return ticks;
> +}
> +
> +static void cqspi_delay(struct cqspi_st *cqspi,
> +                       unsigned int ref_clk_hz, unsigned int sclk_hz)
> +{
> +       void __iomem *iobase = cqspi->iobase;
> +       struct cqspi_flash_pdata *f_pdata;
> +       unsigned int tshsl, tchsh, tslch, tsd2d;
> +       unsigned int reg;
> +       unsigned int tsclk;
> +
> +       f_pdata = &cqspi->f_pdata[cqspi->current_cs];
> +
> +       /* calculate the number of ref ticks for one sclk tick */
> +       tsclk = (ref_clk_hz + sclk_hz - 1) / sclk_hz;
> +
> +       tshsl = calculate_ticks_for_ns(ref_clk_hz, f_pdata->tshsl_ns);
> +       /* this particular value must be at least one sclk */
> +       if (tshsl < tsclk)
> +               tshsl = tsclk;
> +
> +       tchsh = calculate_ticks_for_ns(ref_clk_hz, f_pdata->tchsh_ns);
> +       tslch = calculate_ticks_for_ns(ref_clk_hz, f_pdata->tslch_ns);
> +       tsd2d = calculate_ticks_for_ns(ref_clk_hz, f_pdata->tsd2d_ns);
> +
> +       reg = ((tshsl & CQSPI_REG_DELAY_TSHSL_MASK)
> +              << CQSPI_REG_DELAY_TSHSL_LSB);
> +       reg |= ((tchsh & CQSPI_REG_DELAY_TCHSH_MASK)
> +               << CQSPI_REG_DELAY_TCHSH_LSB);
> +       reg |= ((tslch & CQSPI_REG_DELAY_TSLCH_MASK)
> +               << CQSPI_REG_DELAY_TSLCH_LSB);
> +       reg |= ((tsd2d & CQSPI_REG_DELAY_TSD2D_MASK)
> +               << CQSPI_REG_DELAY_TSD2D_LSB);
> +       writel(reg, iobase + CQSPI_REG_DELAY);
> +}
> +
> +static void cqspi_config_baudrate_div(struct cqspi_st *cqspi,
> +                                     unsigned int ref_clk_hz,
> +                                     unsigned int sclk_hz)
> +{
> +       void __iomem *reg_base = cqspi->iobase;
> +       unsigned int reg;
> +       unsigned int div;
> +
> +       reg = readl(reg_base + CQSPI_REG_CONFIG);
> +       reg &= ~(CQSPI_REG_CONFIG_BAUD_MASK << CQSPI_REG_CONFIG_BAUD_LSB);
> +
> +       div = ref_clk_hz / sclk_hz;
> +
> +       /* Recalculate the baudrate divisor based on QSPI specification. */
> +       if (div > 32)
> +               div = 32;
> +
> +       /* Check if even number. */
> +       if (div & 1)
> +               div = (div / 2);
> +       else
> +               div = (div / 2) - 1;
> +
> +       div = (div & CQSPI_REG_CONFIG_BAUD_MASK) << CQSPI_REG_CONFIG_BAUD_LSB;
> +       reg |= div;
> +       writel(reg, reg_base + CQSPI_REG_CONFIG);
> +}
> +
> +static void cqspi_readdata_capture(struct cqspi_st *cqspi,
> +                                  unsigned int bypass, unsigned int delay)
> +{
> +       void __iomem *reg_base = cqspi->iobase;
> +       unsigned int reg;
> +
> +       reg = readl(reg_base + CQSPI_REG_READCAPTURE);
> +
> +       if (bypass)
> +               reg |= (1 << CQSPI_REG_READCAPTURE_BYPASS_LSB);
> +       else
> +               reg &= ~(1 << CQSPI_REG_READCAPTURE_BYPASS_LSB);
> +
> +       reg &= ~(CQSPI_REG_READCAPTURE_DELAY_MASK
> +                << CQSPI_REG_READCAPTURE_DELAY_LSB);
> +
> +       reg |= ((delay & CQSPI_REG_READCAPTURE_DELAY_MASK)
> +               << CQSPI_REG_READCAPTURE_DELAY_LSB);
> +
> +       writel(reg, reg_base + CQSPI_REG_READCAPTURE);
> +}
> +
> +static void cqspi_chipselect(struct cqspi_st *cqspi,
> +                            unsigned int chip_select,
> +                            unsigned int decoder_enable)
> +{
> +       void __iomem *reg_base = cqspi->iobase;
> +       unsigned int reg;
> +
> +       reg = readl(reg_base + CQSPI_REG_CONFIG);
> +       if (decoder_enable) {
> +               reg |= CQSPI_REG_CONFIG_DECODE_MASK;
> +       } else {
> +               reg &= ~CQSPI_REG_CONFIG_DECODE_MASK;
> +
> +               /* Convert CS if without decoder.
> +                * CS0 to 4b'1110
> +                * CS1 to 4b'1101
> +                * CS2 to 4b'1011
> +                * CS3 to 4b'0111
> +                */
> +               chip_select = 0xF & ~(1 << chip_select);
> +       }
> +
> +       reg &= ~(CQSPI_REG_CONFIG_CHIPSELECT_MASK
> +                << CQSPI_REG_CONFIG_CHIPSELECT_LSB);
> +       reg |= (chip_select & CQSPI_REG_CONFIG_CHIPSELECT_MASK)
> +           << CQSPI_REG_CONFIG_CHIPSELECT_LSB;
> +       writel(reg, reg_base + CQSPI_REG_CONFIG);
> +}
> +
> +static void cqspi_controller_enable(struct cqspi_st *cqspi)
> +{
> +       void __iomem *reg_base = cqspi->iobase;
> +       unsigned int reg;
> +
> +       reg = readl(reg_base + CQSPI_REG_CONFIG);
> +       reg |= CQSPI_REG_CONFIG_ENABLE_MASK;
> +       writel(reg, reg_base + CQSPI_REG_CONFIG);
> +}
> +
> +static void cqspi_controller_disable(struct cqspi_st *cqspi)
> +{
> +       void __iomem *reg_base = cqspi->iobase;
> +       unsigned int reg;
> +
> +       reg = readl(reg_base + CQSPI_REG_CONFIG);
> +       reg &= ~CQSPI_REG_CONFIG_ENABLE_MASK;
> +       writel(reg, reg_base + CQSPI_REG_CONFIG);
> +}
> +
> +static void cqspi_switch_cs(struct cqspi_st *cqspi, unsigned int cs)
> +{
> +       unsigned int reg;
> +       struct cqspi_flash_pdata *f_pdata = &cqspi->f_pdata[cs];
> +       void __iomem *iobase = cqspi->iobase;
> +       struct spi_nor *nor = &f_pdata->nor;
> +
> +       cqspi_controller_disable(cqspi);
> +
> +       /* configure page size and block size. */
> +       reg = readl(iobase + CQSPI_REG_SIZE);
> +       reg &= ~(CQSPI_REG_SIZE_PAGE_MASK << CQSPI_REG_SIZE_PAGE_LSB);
> +       reg &= ~(CQSPI_REG_SIZE_BLOCK_MASK << CQSPI_REG_SIZE_BLOCK_LSB);
> +       reg |= (nor->page_size << CQSPI_REG_SIZE_PAGE_LSB);
> +       reg |= (ilog2(nor->mtd->erasesize) << CQSPI_REG_SIZE_BLOCK_LSB);
> +       reg &= ~CQSPI_REG_SIZE_ADDRESS_MASK;
> +       reg |= (nor->addr_width - 1);
> +       writel(reg, iobase + CQSPI_REG_SIZE);
> +
> +       /* configure the chip select */
> +       cqspi_chipselect(cqspi, cs, cqspi->is_decoded_cs);
> +
> +       cqspi_controller_enable(cqspi);
> +}
> +
> +static int cqspi_prep(struct spi_nor *nor, enum spi_nor_ops ops)
> +{
> +       struct cqspi_st *cqspi = nor->priv;
> +       int cs = cqspi_find_chipselect(nor);
> +       struct cqspi_flash_pdata *f_pdata;
> +       unsigned int sclk;
> +
> +       /* Switch chip select. */
> +       if (cqspi->current_cs != cs) {
> +               cqspi->current_cs = cs;
> +               cqspi_switch_cs(cqspi, cs);
> +       }
> +
> +       /* Setup baudrate divisor and delays */
> +       f_pdata = &cqspi->f_pdata[cqspi->current_cs];
> +       sclk = f_pdata->clk_rate;
> +       if (cqspi->sclk != sclk) {
> +               cqspi->sclk = sclk;
> +               cqspi_controller_disable(cqspi);
> +               cqspi_config_baudrate_div(cqspi,
> +                                         cqspi->master_ref_clk_hz, sclk);
> +               cqspi_delay(cqspi, cqspi->master_ref_clk_hz, sclk);
> +               cqspi_readdata_capture(cqspi, 1, f_pdata->read_delay);
> +               cqspi_controller_enable(cqspi);
> +       }
> +       return 0;
> +}
> +
> +static int cqspi_read_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
> +{
> +       int ret;
> +
> +       cqspi_prep(nor, SPI_NOR_OPS_READ);
> +
> +       ret = cqspi_command_read(nor, &opcode, 1, buf, len);
> +       return ret;
> +}
> +
> +static int cqspi_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len,
> +                          int write_enable)
> +{
> +       int ret = 0;
> +
> +       cqspi_prep(nor, SPI_NOR_OPS_WRITE);
> +
> +       ret = cqspi_command_write(nor, opcode, buf, len);
> +       return ret;
> +}
> +
> +static int cqspi_of_get_flash_pdata(struct platform_device *pdev,
> +                                   struct cqspi_flash_pdata *f_pdata,
> +                                   struct device_node *np)
> +{
> +       if (of_property_read_u32(np, "cdns,read-delay", &f_pdata->read_delay)) {
> +               dev_err(&pdev->dev, "couldn't determine read-delay\n");
> +               return -ENXIO;
> +       }
> +
> +       if (of_property_read_u32(np, "cdns,tshsl-ns", &f_pdata->tshsl_ns)) {
> +               dev_err(&pdev->dev, "couldn't determine tshsl-ns\n");
> +               return -ENXIO;
> +       }
> +
> +       if (of_property_read_u32(np, "cdns,tsd2d-ns", &f_pdata->tsd2d_ns)) {
> +               dev_err(&pdev->dev, "couldn't determine tsd2d-ns\n");
> +               return -ENXIO;
> +       }
> +
> +       if (of_property_read_u32(np, "cdns,tchsh-ns", &f_pdata->tchsh_ns)) {
> +               dev_err(&pdev->dev, "couldn't determine tchsh-ns\n");
> +               return -ENXIO;
> +       }
> +
> +       if (of_property_read_u32(np, "cdns,tslch-ns", &f_pdata->tslch_ns)) {
> +               dev_err(&pdev->dev, "couldn't determine tslch-ns\n");
> +               return -ENXIO;
> +       }
> +
> +       if (of_property_read_u32(np, "spi-max-frequency", &f_pdata->clk_rate)) {
> +               dev_err(&pdev->dev, "couldn't determine spi-max-frequency\n");
> +               return -ENXIO;
> +       }
> +
> +       return 0;
> +}
> +
> +static int cqspi_of_get_pdata(struct platform_device *pdev)
> +{
> +       struct device_node *np = pdev->dev.of_node;
> +       struct cqspi_st *cqspi = platform_get_drvdata(pdev);
> +
> +       if (of_property_read_u32(np, "is-decoded-cs", &cqspi->is_decoded_cs))
> +               cqspi->is_decoded_cs = 0;
> +
> +       if (of_property_read_u32(np, "fifo-depth", &cqspi->fifo_depth)) {
> +               dev_err(&pdev->dev, "couldn't determine fifo-depth\n");
> +               return -ENXIO;
> +       }
> +
> +       return 0;
> +}
> +
> +static void cqspi_controller_init(struct cqspi_st *cqspi)
> +{
> +       cqspi_controller_disable(cqspi);
> +
> +       /* Configure the remap address register, no remap */
> +       writel(0, cqspi->iobase + CQSPI_REG_REMAP);
> +
> +       /* Disable all interrupts. */
> +       writel(0, cqspi->iobase + CQSPI_REG_IRQMASK);
> +
> +       /* Configure the SRAM split to 1:1 . */
> +       writel(0x40, cqspi->iobase + CQSPI_REG_SRAMPARTITION);
> +
> +       cqspi_controller_enable(cqspi);
> +}
> +
> +static int cqspi_remove(struct platform_device *pdev)
> +{
> +       struct cqspi_st *cqspi = platform_get_drvdata(pdev);
> +       int i;
> +
> +       cqspi_controller_disable(cqspi);
> +
> +       for (i = 0; i < CQSPI_MAX_CHIPSELECT; i++)
> +               if (cqspi->f_pdata[i].mtd.name)
> +                       mtd_device_unregister(&cqspi->f_pdata[i].mtd);
> +
> +       return 0;
> +}
> +
> +static int cqspi_probe(struct platform_device *pdev)
> +{
> +       struct device_node *np = pdev->dev.of_node;
> +       struct mtd_part_parser_data ppdata;
> +       struct device *dev = &pdev->dev;
> +       struct cqspi_st *cqspi;
> +       struct spi_nor *nor;
> +       struct mtd_info *mtd;
> +       struct resource *res;
> +       struct resource *res_ahb;
> +       int ret;
> +       int irq;
> +
> +       cqspi = devm_kzalloc(dev, sizeof(*cqspi), GFP_KERNEL);
> +       if (!cqspi)
> +               return -ENOMEM;
> +
> +       cqspi->pdev = pdev;
> +       platform_set_drvdata(pdev, cqspi);
> +
> +       ret = cqspi_of_get_pdata(pdev);
> +       if (ret) {
> +               dev_err(dev, "Get platform data failed.\n");
> +               return -ENODEV;
> +       }
> +
> +       cqspi->clk = devm_clk_get(dev, NULL);
> +       if (IS_ERR(cqspi->clk)) {
> +               dev_err(dev, "cannot get qspi clk\n");
> +               ret = PTR_ERR(cqspi->clk);
> +               goto probe_failed;
> +       }
> +       cqspi->master_ref_clk_hz = clk_get_rate(cqspi->clk);
> +
> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +       cqspi->iobase = devm_ioremap_resource(dev, res);
> +       if (IS_ERR(cqspi->iobase)) {
> +               dev_err(dev, "devm_ioremap_resource res 0 failed\n");
> +               ret = PTR_ERR(cqspi->iobase);
> +               goto probe_failed;
> +       }
> +
> +       res_ahb = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> +       cqspi->ahb_phy_addr = res_ahb->start;
> +       cqspi->ahb_base = devm_ioremap_resource(dev, res_ahb);
> +       if (IS_ERR(cqspi->ahb_base)) {
> +               dev_err(dev, "devm_ioremap_resource res 1 failed\n");
> +               ret = PTR_ERR(cqspi->ahb_base);
> +               goto probe_failed;
> +       }
> +
> +       init_completion(&cqspi->transfer_complete);
> +
> +       irq = platform_get_irq(pdev, 0);
> +       if (irq < 0) {
> +               dev_err(dev, "platform_get_irq failed\n");
> +               ret = -ENXIO;
> +               goto probe_failed;
> +       }
> +       ret = devm_request_irq(dev, irq,
> +                              cqspi_irq_handler, 0, pdev->name, cqspi);
> +       if (ret) {
> +               dev_err(dev, "devm_request_irq failed\n");
> +               goto probe_failed;
> +       }
> +
> +       cqspi_wait_idle(cqspi);
> +       cqspi_controller_init(cqspi);
> +       cqspi->current_cs = -1;
> +       cqspi->sclk = 0;
> +
> +       /* Get flash device data */
> +       for_each_available_child_of_node(dev->of_node, np) {
> +               unsigned int cs;
> +               struct cqspi_flash_pdata *f_pdata;
> +
> +               if (of_property_read_u32(np, "reg", &cs)) {
> +                       dev_err(dev, "couldn't determine chip select\n");
> +                       return -ENXIO;
> +               }
> +               if (cs >= CQSPI_MAX_CHIPSELECT) {
> +                       dev_err(dev, "chip select %d out of range\n", cs);
> +                       return -ENXIO;
> +               }
> +               f_pdata = &cqspi->f_pdata[cs];
> +
> +               ret = cqspi_of_get_flash_pdata(pdev, f_pdata, np);
> +               if (ret)
> +                       goto probe_failed;
> +
> +               nor = &f_pdata->nor;
> +               mtd = &f_pdata->mtd;
> +
> +               nor->mtd = mtd;
> +               nor->dev = dev;
> +               nor->priv = cqspi;
> +               mtd->priv = nor;
> +
> +               nor->read_reg = cqspi_read_reg;
> +               nor->write_reg = cqspi_write_reg;
> +               nor->read = cqspi_read;
> +               nor->write = cqspi_write;
> +               nor->erase = cqspi_erase;
> +
> +               nor->prepare = cqspi_prep;
> +
> +               ret = spi_nor_scan(nor, NULL, SPI_NOR_QUAD);
> +               if (ret)
> +                       goto probe_failed;
> +
> +               if (nor->read_dummy > CQSPI_DUMMY_CLKS_MAX)
> +                       nor->read_dummy = CQSPI_DUMMY_CLKS_MAX;
> +
> +               ppdata.of_node = np;
> +               ret = mtd_device_parse_register(mtd, NULL, &ppdata, NULL, 0);
> +               if (ret)
> +                       goto probe_failed;
> +       }
> +
> +       dev_info(dev, "Cadence QSPI NOR flash driver\n");
> +       return 0;
> +
> + probe_failed:
> +       dev_err(dev, "Cadence QSPI NOR probe failed %d\n", ret);
> +       cqspi_remove(pdev);
> +       return ret;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int cqspi_suspend(struct device *dev)
> +{
> +       struct cqspi_st *cqspi = dev_get_drvdata(dev);
> +
> +       cqspi_controller_disable(cqspi);
> +       return 0;
> +}
> +
> +static int cqspi_resume(struct device *dev)
> +{
> +       struct cqspi_st *cqspi = dev_get_drvdata(dev);
> +
> +       cqspi_controller_enable(cqspi);
> +       return 0;
> +}
> +
> +static const struct dev_pm_ops cqspi__dev_pm_ops = {
> +       .suspend = cqspi_suspend,
> +       .resume = cqspi_resume,
> +};
> +
> +#define CQSPI_DEV_PM_OPS       (&cqspi__dev_pm_ops)
> +#else
> +#define CQSPI_DEV_PM_OPS       NULL
> +#endif
> +
> +static struct of_device_id const cqspi_dt_ids[] = {
> +       {.compatible = "cdns,qspi-nor",},
> +       { /* end of table */ }
> +};
> +
> +MODULE_DEVICE_TABLE(of, cqspi_dt_ids);
> +
> +static struct platform_driver cqspi_platform_driver = {
> +       .probe = cqspi_probe,
> +       .remove = cqspi_remove,
> +       .driver = {
> +               .name = CQSPI_NAME,
> +               .pm = CQSPI_DEV_PM_OPS,
> +               .of_match_table = cqspi_dt_ids,
> +       },
> +};
> +
> +module_platform_driver(cqspi_platform_driver);
> +
> +MODULE_DESCRIPTION("Cadence QSPI Controller Driver");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:" CQSPI_NAME);
> +MODULE_AUTHOR("Ley Foon Tan <lftan at altera.com>");
> +MODULE_AUTHOR("Graham Moore <grmoore at opensource.altera.com>");
> --
> 1.7.9.5
>
> --
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