Re: [PATCH v2 5/6] mtd: spi-nor: Convert cadence-quadspi to use spi-mem framework

[<Tudor.Ambarus@xxxxxxxxxxxxx>]

Hi, Vignesh,

On Tuesday, May 26, 2020 12:36:03 PM EEST Vignesh Raghavendra wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the
> content is safe
> 
> From: Ramuthevar Vadivel Murugan
> <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx>
> 
> Move cadence-quadspi driver to use spi-mem framework. This is required
> to make the driver support for SPI NAND flashes in future.
> 
> Driver is feature compliant with existing SPI NOR version.
> 
> Signed-off-by: Ramuthevar Vadivel Murugan
> <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx> Signed-off-by: Vignesh
> Raghavendra <vigneshr@xxxxxx>
> ---
>  .../mtd/spi-nor/controllers/cadence-quadspi.c | 469 +++++++-----------
>  1 file changed, 183 insertions(+), 286 deletions(-)
> 
> diff --git a/drivers/mtd/spi-nor/controllers/cadence-quadspi.c
> b/drivers/mtd/spi-nor/controllers/cadence-quadspi.c index
> 608ca657ff7f..c1df4b221889 100644
> --- a/drivers/mtd/spi-nor/controllers/cadence-quadspi.c
> +++ b/drivers/mtd/spi-nor/controllers/cadence-quadspi.c
> @@ -3,6 +3,8 @@
>   * Driver for Cadence QSPI Controller
>   *
>   * Copyright Altera Corporation (C) 2012-2014. All rights reserved.
> + * Copyright Intel Corporation (C) 2019-2020. All rights reserved.
> + * Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com
>   */
>  #include <linux/clk.h>
>  #include <linux/completion.h>
> @@ -17,9 +19,6 @@
>  #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>
> @@ -27,6 +26,7 @@
>  #include <linux/reset.h>
>  #include <linux/sched.h>
>  #include <linux/spi/spi.h>
> +#include <linux/spi/spi-mem.h>
>  #include <linux/timer.h>
> 
>  #define CQSPI_NAME                     "cadence-qspi"
> @@ -36,16 +36,12 @@
>  #define CQSPI_NEEDS_WR_DELAY           BIT(0)
>  #define CQSPI_DISABLE_DAC_MODE         BIT(1)
> 
> -/* Capabilities mask */
> -#define CQSPI_BASE_HWCAPS_MASK                                 \
> -       (SNOR_HWCAPS_READ | SNOR_HWCAPS_READ_FAST |             \
> -       SNOR_HWCAPS_READ_1_1_2 | SNOR_HWCAPS_READ_1_1_4 |       \
> -       SNOR_HWCAPS_PP)
> +/* Capabilities */
> +#define CQSPI_SUPPORTS_OCTAL           BIT(0)
> 
>  struct cqspi_st;
> 
>  struct cqspi_flash_pdata {
> -       struct spi_nor  nor;
>         struct cqspi_st *cqspi;
>         u32             clk_rate;
>         u32             read_delay;
> @@ -58,7 +54,6 @@ struct cqspi_flash_pdata {
>         u8              data_width;
>         u8              cs;
>         bool            registered;

you can drop this, as it is no longer used

> -       bool            use_direct_mode;
>  };
> 
>  struct cqspi_st {
> @@ -71,7 +66,6 @@ struct cqspi_st {
>         void __iomem            *ahb_base;
>         resource_size_t         ahb_size;
>         struct completion       transfer_complete;
> -       struct mutex            bus_mutex;
> 
>         struct dma_chan         *rx_chan;
>         struct completion       rx_dma_complete;
> @@ -85,6 +79,7 @@ struct cqspi_st {
>         bool                    rclk_en;
>         u32                     trigger_address;
>         u32                     wr_delay;
> +       bool                    use_dac_mode;

is use_dac_mode better than use_direct_mode? If you prefer "dac", maybe you 
can rename this variable in 2/6

>         struct cqspi_flash_pdata f_pdata[CQSPI_MAX_CHIPSELECT];
>  };
> 
> @@ -283,9 +278,8 @@ static irqreturn_t cqspi_irq_handler(int this_irq, void
> *dev) return IRQ_HANDLED;
>  }
> 
> -static unsigned int cqspi_calc_rdreg(struct spi_nor *nor)
> +static unsigned int cqspi_calc_rdreg(struct cqspi_flash_pdata *f_pdata)
>  {
> -       struct cqspi_flash_pdata *f_pdata = nor->priv;
>         u32 rdreg = 0;
> 
>         rdreg |= f_pdata->inst_width << CQSPI_REG_RD_INSTR_TYPE_INSTR_LSB;
> @@ -352,19 +346,21 @@ static int cqspi_exec_flash_cmd(struct cqspi_st
> *cqspi, unsigned int reg) return cqspi_wait_idle(cqspi);
>  }
> 
> -static int cqspi_command_read(struct spi_nor *nor, u8 opcode,
> -                             u8 *rxbuf, size_t n_rx)
> +static int cqspi_command_read(struct cqspi_flash_pdata *f_pdata,
> +                             const struct spi_mem_op *op)
>  {
> -       struct cqspi_flash_pdata *f_pdata = nor->priv;
>         struct cqspi_st *cqspi = f_pdata->cqspi;
>         void __iomem *reg_base = cqspi->iobase;
> +       u8 *rxbuf = op->data.buf.in;
> +       u8 opcode = op->cmd.opcode;

dedicated variable for opcode is not really needed, it is used only once.

> +       size_t n_rx = op->data.nbytes;
>         unsigned int rdreg;
>         unsigned int reg;
>         size_t read_len;
>         int status;
> 
>         if (!n_rx || n_rx > CQSPI_STIG_DATA_LEN_MAX || !rxbuf) {
> -               dev_err(nor->dev,
> +               dev_err(&cqspi->pdev->dev,
>                         "Invalid input argument, len %zu rxbuf 0x%p\n",
>                         n_rx, rxbuf);
>                 return -EINVAL;
> @@ -372,7 +368,7 @@ static int cqspi_command_read(struct spi_nor *nor, u8
> opcode,
> 
>         reg = opcode << CQSPI_REG_CMDCTRL_OPCODE_LSB;
> 
> -       rdreg = cqspi_calc_rdreg(nor);
> +       rdreg = cqspi_calc_rdreg(f_pdata);
>         writel(rdreg, reg_base + CQSPI_REG_RD_INSTR);
> 
>         reg |= (0x1 << CQSPI_REG_CMDCTRL_RD_EN_LSB);
> @@ -401,25 +397,35 @@ static int cqspi_command_read(struct spi_nor *nor, u8
> opcode, return 0;
>  }
> 
> -static int cqspi_command_write(struct spi_nor *nor, const u8 opcode,
> -                              const u8 *txbuf, size_t n_tx)
> +static int cqspi_command_write(struct cqspi_flash_pdata *f_pdata,
> +                              const struct spi_mem_op *op)
>  {
> -       struct cqspi_flash_pdata *f_pdata = nor->priv;
>         struct cqspi_st *cqspi = f_pdata->cqspi;
>         void __iomem *reg_base = cqspi->iobase;
> +       const u8 opcode = op->cmd.opcode;

dedicated variable for opcode is not really needed, it is used only once.

> +       const u8 *txbuf = op->data.buf.out;
> +       size_t n_tx = op->data.nbytes;
>         unsigned int reg;
>         unsigned int data;
>         size_t write_len;
> -       int ret;
> 
>         if (n_tx > CQSPI_STIG_DATA_LEN_MAX || (n_tx && !txbuf)) {
> -               dev_err(nor->dev,
> +               dev_err(&cqspi->pdev->dev,
>                         "Invalid input argument, cmdlen %zu txbuf 0x%p\n",
>                         n_tx, txbuf);
>                 return -EINVAL;
>         }
> 
>         reg = opcode << CQSPI_REG_CMDCTRL_OPCODE_LSB;
> +
> +       if (op->addr.nbytes) {
> +               reg |= (0x1 << CQSPI_REG_CMDCTRL_ADDR_EN_LSB);
> +               reg |= ((op->addr.nbytes - 1) &
> CQSPI_REG_CMDCTRL_ADD_BYTES_MASK)
> +               <<
> CQSPI_REG_CMDCTRL_ADD_BYTES_LSB;

you have a 80 chars checkpatch warning here, maybe replace it with smth like
	reg |= ((op->addr.nbytes - 1) &
	            CQSPI_REG_CMDCTRL_ADD_BYTES_MASK) <<
	           CQSPI_REG_CMDCTRL_ADD_BYTES_LSB;

> +
> +               writel(op->addr.val, reg_base + CQSPI_REG_CMDADDRESS);
> +       }
> +
>         if (n_tx) {
>                 reg |= (0x1 << CQSPI_REG_CMDCTRL_WR_EN_LSB);
>                 reg |= ((n_tx - 1) & CQSPI_REG_CMDCTRL_WR_BYTES_MASK)
> @@ -437,73 +443,46 @@ static int cqspi_command_write(struct spi_nor *nor,
> const u8 opcode, writel(data, reg_base + CQSPI_REG_CMDWRITEDATAUPPER); }
>         }
> -       ret = cqspi_exec_flash_cmd(cqspi, reg);
> -       return ret;
> -}
> -
> -static int cqspi_command_write_addr(struct spi_nor *nor,
> -                                   const u8 opcode, const unsigned int
> addr) -{
> -       struct cqspi_flash_pdata *f_pdata = nor->priv;
> -       struct cqspi_st *cqspi = f_pdata->cqspi;
> -       void __iomem *reg_base = cqspi->iobase;
> -       unsigned int reg;
> -
> -       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_read_setup(struct spi_nor *nor)
> +static int cqspi_read_setup(struct cqspi_flash_pdata *f_pdata,
> +                           const struct spi_mem_op *op)
>  {
> -       struct cqspi_flash_pdata *f_pdata = nor->priv;
>         struct cqspi_st *cqspi = f_pdata->cqspi;
>         void __iomem *reg_base = cqspi->iobase;
>         unsigned int dummy_clk = 0;
>         unsigned int reg;
> 
> -       reg = nor->read_opcode << CQSPI_REG_RD_INSTR_OPCODE_LSB;
> -       reg |= cqspi_calc_rdreg(nor);
> +       reg = op->cmd.opcode << CQSPI_REG_RD_INSTR_OPCODE_LSB;
> +       reg |= cqspi_calc_rdreg(f_pdata);
> 
>         /* Setup dummy clock cycles */
> -       dummy_clk = nor->read_dummy;
> +       dummy_clk = op->dummy.nbytes * 8;
>         if (dummy_clk > CQSPI_DUMMY_CLKS_MAX)
>                 dummy_clk = CQSPI_DUMMY_CLKS_MAX;
> 
> -       if (dummy_clk / 8) {
> -               reg |= (1 << CQSPI_REG_RD_INSTR_MODE_EN_LSB);
> -               /* Set mode bits high to ensure chip doesn't enter XIP */
> -               writel(0xFF, reg_base + CQSPI_REG_MODE_BIT);
> -
> -               /* Need to subtract the mode byte (8 clocks). */
> -               if (f_pdata->inst_width != CQSPI_INST_TYPE_QUAD)
> -                       dummy_clk -= 8;
> -
> -               if (dummy_clk)
> -                       reg |= (dummy_clk & CQSPI_REG_RD_INSTR_DUMMY_MASK)
> -                              << CQSPI_REG_RD_INSTR_DUMMY_LSB;
> -       }
> +       if (dummy_clk / 8)

if (dummy_clk) should be enough. dummy_clk is either zero, or a multiple of 
eight, or CQSPI_DUMMY_CLKS_MAX.

> +               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);
> +       reg |= (op->addr.nbytes - 1);
>         writel(reg, reg_base + CQSPI_REG_SIZE);
>         return 0;
>  }
> 
> -static int cqspi_indirect_read_execute(struct spi_nor *nor, u8 *rxbuf,
> -                                      loff_t from_addr, const size_t n_rx)
> +static int cqspi_indirect_read_execute(struct cqspi_flash_pdata *f_pdata,
> +                                      u8 *rxbuf, loff_t from_addr,
> +                                      const size_t n_rx)
>  {
> -       struct cqspi_flash_pdata *f_pdata = nor->priv;
>         struct cqspi_st *cqspi = f_pdata->cqspi;
> +       struct device *dev = &cqspi->pdev->dev;
>         void __iomem *reg_base = cqspi->iobase;
>         void __iomem *ahb_base = cqspi->ahb_base;
>         unsigned int remaining = n_rx;
> @@ -526,13 +505,13 @@ static int cqspi_indirect_read_execute(struct spi_nor
> *nor, u8 *rxbuf,
> 
>         while (remaining > 0) {
>                 if (!wait_for_completion_timeout(&cqspi->transfer_complete,
> -                               msecs_to_jiffies(CQSPI_READ_TIMEOUT_MS)))
> +                                               
> msecs_to_jiffies(CQSPI_READ_TIMEOUT_MS))) ret = -ETIMEDOUT;
> 
>                 bytes_to_read = cqspi_get_rd_sram_level(cqspi);
> 
>                 if (ret && bytes_to_read == 0) {
> -                       dev_err(nor->dev, "Indirect read timeout, no
> bytes\n"); +                       dev_err(dev, "Indirect read timeout, no
> bytes\n"); goto failrd;
>                 }
> 
> @@ -568,8 +547,7 @@ static int cqspi_indirect_read_execute(struct spi_nor
> *nor, u8 *rxbuf, ret = cqspi_wait_for_bit(reg_base + CQSPI_REG_INDIRECTRD,
>                                  CQSPI_REG_INDIRECTRD_DONE_MASK, 0);
>         if (ret) {
> -               dev_err(nor->dev,
> -                       "Indirect read completion error (%i)\n", ret);
> +               dev_err(dev, "Indirect read completion error (%i)\n", ret);
>                 goto failrd;
>         }
> 
> @@ -591,32 +569,32 @@ static int cqspi_indirect_read_execute(struct spi_nor
> *nor, u8 *rxbuf, return ret;
>  }
> 
> -static int cqspi_write_setup(struct spi_nor *nor)
> +static int cqspi_write_setup(struct cqspi_flash_pdata *f_pdata,
> +                            const struct spi_mem_op *op)
>  {
>         unsigned int reg;
> -       struct cqspi_flash_pdata *f_pdata = nor->priv;
>         struct cqspi_st *cqspi = f_pdata->cqspi;
>         void __iomem *reg_base = cqspi->iobase;
> 
>         /* Set opcode. */
> -       reg = nor->program_opcode << CQSPI_REG_WR_INSTR_OPCODE_LSB;
> +       reg = op->cmd.opcode << CQSPI_REG_WR_INSTR_OPCODE_LSB;
>         writel(reg, reg_base + CQSPI_REG_WR_INSTR);
> -       reg = cqspi_calc_rdreg(nor);
> +       reg = cqspi_calc_rdreg(f_pdata);
>         writel(reg, reg_base + CQSPI_REG_RD_INSTR);
> 
>         reg = readl(reg_base + CQSPI_REG_SIZE);
>         reg &= ~CQSPI_REG_SIZE_ADDRESS_MASK;
> -       reg |= (nor->addr_width - 1);
> +       reg |= (op->addr.nbytes - 1);
>         writel(reg, reg_base + CQSPI_REG_SIZE);
>         return 0;
>  }
> 
> -static int cqspi_indirect_write_execute(struct spi_nor *nor, loff_t
> to_addr, -                                       const u8 *txbuf, const
> size_t n_tx) +static int cqspi_indirect_write_execute(struct
> cqspi_flash_pdata *f_pdata, +                                       loff_t
> to_addr, const u8 *txbuf, +                                       const
> size_t n_tx)
>  {
> -       const unsigned int page_size = nor->page_size;
> -       struct cqspi_flash_pdata *f_pdata = nor->priv;
>         struct cqspi_st *cqspi = f_pdata->cqspi;
> +       struct device *dev = &cqspi->pdev->dev;
>         void __iomem *reg_base = cqspi->iobase;
>         unsigned int remaining = n_tx;
>         unsigned int write_bytes;
> @@ -646,7 +624,7 @@ static int cqspi_indirect_write_execute(struct spi_nor
> *nor, loff_t to_addr, while (remaining > 0) {
>                 size_t write_words, mod_bytes;
> 
> -               write_bytes = remaining > page_size ? page_size : remaining;
> +               write_bytes = remaining;
>                 write_words = write_bytes / 4;
>                 mod_bytes = write_bytes % 4;
>                 /* Write 4 bytes at a time then single bytes. */
> @@ -663,8 +641,8 @@ static int cqspi_indirect_write_execute(struct spi_nor
> *nor, loff_t to_addr, }
> 
>                 if (!wait_for_completion_timeout(&cqspi->transfer_complete,
> -                                       msecs_to_jiffies(CQSPI_TIMEOUT_MS)))
> { -                       dev_err(nor->dev, "Indirect write timeout\n"); + 
>                                              
> msecs_to_jiffies(CQSPI_TIMEOUT_MS))) { +                       dev_err(dev,
> "Indirect write timeout\n");
>                         ret = -ETIMEDOUT;
>                         goto failwr;
>                 }
> @@ -679,8 +657,7 @@ static int cqspi_indirect_write_execute(struct spi_nor
> *nor, loff_t to_addr, ret = cqspi_wait_for_bit(reg_base +
> CQSPI_REG_INDIRECTWR,
>                                  CQSPI_REG_INDIRECTWR_DONE_MASK, 0);
>         if (ret) {
> -               dev_err(nor->dev,
> -                       "Indirect write completion error (%i)\n", ret);
> +               dev_err(dev, "Indirect write completion error (%i)\n", ret);
> goto failwr;
>         }
> 
> @@ -704,9 +681,8 @@ static int cqspi_indirect_write_execute(struct spi_nor
> *nor, loff_t to_addr, return ret;
>  }
> 
> -static void cqspi_chipselect(struct spi_nor *nor)
> +static void cqspi_chipselect(struct cqspi_flash_pdata *f_pdata)
>  {
> -       struct cqspi_flash_pdata *f_pdata = nor->priv;
>         struct cqspi_st *cqspi = f_pdata->cqspi;
>         void __iomem *reg_base = cqspi->iobase;
>         unsigned int chip_select = f_pdata->cs;
> @@ -745,9 +721,8 @@ static unsigned int calculate_ticks_for_ns(const
> unsigned int ref_clk_hz, return ticks;
>  }
> 
> -static void cqspi_delay(struct spi_nor *nor)
> +static void cqspi_delay(struct cqspi_flash_pdata *f_pdata)
>  {
> -       struct cqspi_flash_pdata *f_pdata = nor->priv;
>         struct cqspi_st *cqspi = f_pdata->cqspi;
>         void __iomem *iobase = cqspi->iobase;
>         const unsigned int ref_clk_hz = cqspi->master_ref_clk_hz;
> @@ -831,11 +806,10 @@ static void cqspi_controller_enable(struct cqspi_st
> *cqspi, bool enable) writel(reg, reg_base + CQSPI_REG_CONFIG);
>  }
> 
> -static void cqspi_configure(struct spi_nor *nor)
> +static void cqspi_configure(struct cqspi_flash_pdata *f_pdata,
> +                           unsigned long sclk)
>  {
> -       struct cqspi_flash_pdata *f_pdata = nor->priv;
>         struct cqspi_st *cqspi = f_pdata->cqspi;
> -       const unsigned int sclk = f_pdata->clk_rate;
>         int switch_cs = (cqspi->current_cs != f_pdata->cs);
>         int switch_ck = (cqspi->sclk != sclk);
> 
> @@ -845,14 +819,14 @@ static void cqspi_configure(struct spi_nor *nor)
>         /* Switch chip select. */
>         if (switch_cs) {
>                 cqspi->current_cs = f_pdata->cs;
> -               cqspi_chipselect(nor);
> +               cqspi_chipselect(f_pdata);
>         }
> 
>         /* Setup baudrate divisor and delays */
>         if (switch_ck) {
>                 cqspi->sclk = sclk;
>                 cqspi_config_baudrate_div(cqspi);
> -               cqspi_delay(nor);
> +               cqspi_delay(f_pdata);
>                 cqspi_readdata_capture(cqspi, !cqspi->rclk_en,
>                                        f_pdata->read_delay);
>         }
> @@ -861,26 +835,25 @@ static void cqspi_configure(struct spi_nor *nor)
>                 cqspi_controller_enable(cqspi, 1);
>  }
> 
> -static int cqspi_set_protocol(struct spi_nor *nor, const int read)
> +static int cqspi_set_protocol(struct cqspi_flash_pdata *f_pdata,
> +                             const struct spi_mem_op *op)
>  {
> -       struct cqspi_flash_pdata *f_pdata = nor->priv;
> -
>         f_pdata->inst_width = CQSPI_INST_TYPE_SINGLE;
>         f_pdata->addr_width = CQSPI_INST_TYPE_SINGLE;
>         f_pdata->data_width = CQSPI_INST_TYPE_SINGLE;
> 
> -       if (read) {
> -               switch (nor->read_proto) {
> -               case SNOR_PROTO_1_1_1:
> +       if (op->data.dir == SPI_MEM_DATA_IN) {
> +               switch (op->data.buswidth) {
> +               case 1:
>                         f_pdata->data_width = CQSPI_INST_TYPE_SINGLE;
>                         break;
> -               case SNOR_PROTO_1_1_2:
> +               case 2:
>                         f_pdata->data_width = CQSPI_INST_TYPE_DUAL;
>                         break;
> -               case SNOR_PROTO_1_1_4:
> +               case 4:
>                         f_pdata->data_width = CQSPI_INST_TYPE_QUAD;
>                         break;
> -               case SNOR_PROTO_1_1_8:
> +               case 8:
>                         f_pdata->data_width = CQSPI_INST_TYPE_OCTAL;
>                         break;
>                 default:
> @@ -888,36 +861,32 @@ static int cqspi_set_protocol(struct spi_nor *nor,
> const int read) }
>         }
> 
> -       cqspi_configure(nor);
> -
>         return 0;
>  }
> 
> -static ssize_t cqspi_write(struct spi_nor *nor, loff_t to,
> -                          size_t len, const u_char *buf)
> +static ssize_t cqspi_write(struct cqspi_flash_pdata *f_pdata,
> +                          const struct spi_mem_op *op)
>  {
> -       struct cqspi_flash_pdata *f_pdata = nor->priv;
>         struct cqspi_st *cqspi = f_pdata->cqspi;
> +       loff_t to = op->addr.val;
> +       size_t len = op->data.nbytes;
> +       const u_char *buf = op->data.buf.out;
>         int ret;
> 
> -       ret = cqspi_set_protocol(nor, 0);
> +       ret = cqspi_set_protocol(f_pdata, op);
>         if (ret)
>                 return ret;
> 
> -       ret = cqspi_write_setup(nor);
> +       ret = cqspi_write_setup(f_pdata, op);
>         if (ret)
>                 return ret;
> 
> -       if (f_pdata->use_direct_mode) {
> +       if (cqspi->use_dac_mode && ((to + len) <= cqspi->ahb_size)) {
>                 memcpy_toio(cqspi->ahb_base + to, buf, len);
> -               ret = cqspi_wait_idle(cqspi);
> -       } else {
> -               ret = cqspi_indirect_write_execute(nor, to, buf, len);
> +               return cqspi_wait_idle(cqspi);
>         }
> -       if (ret)
> -               return ret;
> 
> -       return len;
> +       return cqspi_indirect_write_execute(f_pdata, to, buf, len);
>  }
> 
>  static void cqspi_rx_dma_callback(void *param)
> @@ -927,11 +896,11 @@ static void cqspi_rx_dma_callback(void *param)
>         complete(&cqspi->rx_dma_complete);
>  }
> 
> -static int cqspi_direct_read_execute(struct spi_nor *nor, u_char *buf,
> -                                    loff_t from, size_t len)
> +static int cqspi_direct_read_execute(struct cqspi_flash_pdata *f_pdata,
> +                                    u_char *buf, loff_t from, size_t len)
>  {
> -       struct cqspi_flash_pdata *f_pdata = nor->priv;
>         struct cqspi_st *cqspi = f_pdata->cqspi;
> +       struct device *dev = &cqspi->pdev->dev;
>         enum dma_ctrl_flags flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT;
>         dma_addr_t dma_src = (dma_addr_t)cqspi->mmap_phys_base + from;
>         int ret = 0;
> @@ -944,15 +913,15 @@ static int cqspi_direct_read_execute(struct spi_nor
> *nor, u_char *buf, return 0;
>         }
> 
> -       dma_dst = dma_map_single(nor->dev, buf, len, DMA_FROM_DEVICE);
> -       if (dma_mapping_error(nor->dev, dma_dst)) {
> -               dev_err(nor->dev, "dma mapping failed\n");
> +       dma_dst = dma_map_single(dev, buf, len, DMA_FROM_DEVICE);
> +       if (dma_mapping_error(dev, dma_dst)) {
> +               dev_err(dev, "dma mapping failed\n");
>                 return -ENOMEM;
>         }
>         tx = dmaengine_prep_dma_memcpy(cqspi->rx_chan, dma_dst, dma_src,
>                                        len, flags);
>         if (!tx) {
> -               dev_err(nor->dev, "device_prep_dma_memcpy error\n");
> +               dev_err(dev, "device_prep_dma_memcpy error\n");
>                 ret = -EIO;
>                 goto err_unmap;
>         }
> @@ -964,7 +933,7 @@ static int cqspi_direct_read_execute(struct spi_nor
> *nor, u_char *buf,
> 
>         ret = dma_submit_error(cookie);
>         if (ret) {
> -               dev_err(nor->dev, "dma_submit_error %d\n", cookie);
> +               dev_err(dev, "dma_submit_error %d\n", cookie);
>                 ret = -EIO;
>                 goto err_unmap;
>         }
> @@ -973,99 +942,68 @@ static int cqspi_direct_read_execute(struct spi_nor
> *nor, u_char *buf, if
> (!wait_for_completion_timeout(&cqspi->rx_dma_complete,
>                                          msecs_to_jiffies(len))) {
>                 dmaengine_terminate_sync(cqspi->rx_chan);
> -               dev_err(nor->dev, "DMA wait_for_completion_timeout\n");
> +               dev_err(dev, "DMA wait_for_completion_timeout\n");
>                 ret = -ETIMEDOUT;
>                 goto err_unmap;
>         }
> 
>  err_unmap:
> -       dma_unmap_single(nor->dev, dma_dst, len, DMA_FROM_DEVICE);
> +       dma_unmap_single(dev, dma_dst, len, DMA_FROM_DEVICE);
> 
>         return ret;
>  }
> 
> -static ssize_t cqspi_read(struct spi_nor *nor, loff_t from,
> -                         size_t len, u_char *buf)
> -{
> -       struct cqspi_flash_pdata *f_pdata = nor->priv;
> -       int ret;
> -
> -       ret = cqspi_set_protocol(nor, 1);
> -       if (ret)
> -               return ret;
> -
> -       ret = cqspi_read_setup(nor);
> -       if (ret)
> -               return ret;
> -
> -       if (f_pdata->use_direct_mode)
> -               ret = cqspi_direct_read_execute(nor, buf, from, len);
> -       else
> -               ret = cqspi_indirect_read_execute(nor, buf, from, len);
> -       if (ret)
> -               return ret;
> -
> -       return len;
> -}
> -
> -static int cqspi_erase(struct spi_nor *nor, loff_t offs)
> +static ssize_t cqspi_read(struct cqspi_flash_pdata *f_pdata,
> +                         const struct spi_mem_op *op)
>  {
> +       struct cqspi_st *cqspi = f_pdata->cqspi;
> +       loff_t from = op->addr.val;
> +       size_t len = op->data.nbytes;
> +       u_char *buf = op->data.buf.in;
>         int ret;
> 
> -       ret = cqspi_set_protocol(nor, 0);
> +       ret = cqspi_set_protocol(f_pdata, op);
>         if (ret)
>                 return ret;
> 
> -       /* Send write enable, then erase commands. */
> -       ret = nor->controller_ops->write_reg(nor, SPINOR_OP_WREN, NULL, 0);

Dropping the Write Enable for erases can be done in a separate patch, since it 
is already done in the SPI NOR core. This would ease the review.

> +       ret = cqspi_read_setup(f_pdata, op);
>         if (ret)
>                 return ret;
> 
> -       /* Set up command buffer. */
> -       ret = cqspi_command_write_addr(nor, nor->erase_opcode, offs);
> -       if (ret)
> -               return ret;
> +       if (cqspi->use_dac_mode && ((from + len) <= cqspi->ahb_size))
> +               return cqspi_direct_read_execute(f_pdata, buf, from, len);
> 
> -       return 0;
> +       return cqspi_indirect_read_execute(f_pdata, buf, from, len);
>  }
> 
> -static int cqspi_prep(struct spi_nor *nor)
> +static int cqspi_mem_process(struct spi_mem *mem, const struct spi_mem_op
> *op) {
> -       struct cqspi_flash_pdata *f_pdata = nor->priv;
> -       struct cqspi_st *cqspi = f_pdata->cqspi;
> -
> -       mutex_lock(&cqspi->bus_mutex);
> -
> -       return 0;
> -}
> +       struct cqspi_st *cqspi = spi_master_get_devdata(mem->spi->master);
> +       struct cqspi_flash_pdata *f_pdata;
> 
> -static void cqspi_unprep(struct spi_nor *nor)
> -{
> -       struct cqspi_flash_pdata *f_pdata = nor->priv;
> -       struct cqspi_st *cqspi = f_pdata->cqspi;
> +       f_pdata = &cqspi->f_pdata[mem->spi->chip_select];
> +       cqspi_configure(f_pdata, mem->spi->max_speed_hz);
> 
> -       mutex_unlock(&cqspi->bus_mutex);
> -}
> +       if (op->data.dir == SPI_MEM_DATA_IN && op->data.buf.in) {
> +               if (!op->addr.nbytes)
> +                       return cqspi_command_read(f_pdata, op);
> 
> -static int cqspi_read_reg(struct spi_nor *nor, u8 opcode, u8 *buf, size_t
> len) -{
> -       int ret;
> +               return cqspi_read(f_pdata, op);
> +       }
> 
> -       ret = cqspi_set_protocol(nor, 0);
> -       if (!ret)
> -               ret = cqspi_command_read(nor, opcode, buf, len);
> +       if (!op->addr.nbytes || !op->data.buf.out)
> +               return cqspi_command_write(f_pdata, op);
> 
> -       return ret;
> +       return cqspi_write(f_pdata, op);
>  }
> 
> -static int cqspi_write_reg(struct spi_nor *nor, u8 opcode, const u8 *buf,
> -                          size_t len)
> +static int cqspi_exec_mem_op(struct spi_mem *mem, const struct spi_mem_op
> *op) {
>         int ret;
> 
> -       ret = cqspi_set_protocol(nor, 0);
> -       if (!ret)
> -               ret = cqspi_command_write(nor, opcode, buf, len);
> +       ret = cqspi_mem_process(mem, op);
> +       if (ret)
> +               dev_err(&mem->spi->dev, "operation failed with %d\n", ret);
> 
>         return ret;
>  }
> @@ -1107,26 +1045,26 @@ static int cqspi_of_get_flash_pdata(struct
> platform_device *pdev, return 0;
>  }
> 
> -static int cqspi_of_get_pdata(struct platform_device *pdev)
> +static int cqspi_of_get_pdata(struct cqspi_st *cqspi)
>  {
> -       struct device_node *np = pdev->dev.of_node;
> -       struct cqspi_st *cqspi = platform_get_drvdata(pdev);
> +       struct device *dev = &cqspi->pdev->dev;
> +       struct device_node *np = dev->of_node;
> 
>         cqspi->is_decoded_cs = of_property_read_bool(np,
> "cdns,is-decoded-cs");
> 
>         if (of_property_read_u32(np, "cdns,fifo-depth", &cqspi->fifo_depth))
> { -               dev_err(&pdev->dev, "couldn't determine fifo-depth\n"); +
>               dev_err(dev, "couldn't determine fifo-depth\n");
>                 return -ENXIO;
>         }
> 
>         if (of_property_read_u32(np, "cdns,fifo-width", &cqspi->fifo_width))
> { -               dev_err(&pdev->dev, "couldn't determine fifo-width\n"); +
>               dev_err(dev, "couldn't determine fifo-width\n");
>                 return -ENXIO;
>         }
> 
>         if (of_property_read_u32(np, "cdns,trigger-address",
>                                  &cqspi->trigger_address)) {
> -               dev_err(&pdev->dev, "couldn't determine trigger-address\n");
> +               dev_err(dev, "couldn't determine trigger-address\n");
> return -ENXIO;
>         }
> 
> @@ -1169,7 +1107,7 @@ static void cqspi_controller_init(struct cqspi_st
> *cqspi) cqspi_controller_enable(cqspi, 1);
>  }
> 
> -static void cqspi_request_mmap_dma(struct cqspi_st *cqspi)
> +static int cqspi_request_mmap_dma(struct cqspi_st *cqspi)
>  {
>         dma_cap_mask_t mask;
> 
> @@ -1178,133 +1116,79 @@ static void cqspi_request_mmap_dma(struct cqspi_st
> *cqspi)
> 
>         cqspi->rx_chan = dma_request_chan_by_mask(&mask);
>         if (IS_ERR(cqspi->rx_chan)) {
> -               dev_err(&cqspi->pdev->dev, "No Rx DMA available\n");
> +               int ret = PTR_ERR(cqspi->rx_chan);
> +
> +               if (ret != -EPROBE_DEFER)
> +                       dev_err(&cqspi->pdev->dev, "No Rx DMA available\n");
> cqspi->rx_chan = NULL;
> -               return;
> +               return ret;
>         }
>         init_completion(&cqspi->rx_dma_complete);
> +
> +       return 0;
>  }

Can we have the EPROBE_DEFER changes in a dedicated patch?

> 
> -static const struct spi_nor_controller_ops cqspi_controller_ops = {
> -       .prepare = cqspi_prep,
> -       .unprepare = cqspi_unprep,
> -       .read_reg = cqspi_read_reg,
> -       .write_reg = cqspi_write_reg,
> -       .read = cqspi_read,
> -       .write = cqspi_write,
> -       .erase = cqspi_erase,
> +static const struct spi_controller_mem_ops cqspi_mem_ops = {
> +       .exec_op = cqspi_exec_mem_op,
>  };
> 
> -static int cqspi_setup_flash(struct cqspi_st *cqspi, struct device_node
> *np) +static int cqspi_setup_flash(struct cqspi_st *cqspi)
>  {
>         struct platform_device *pdev = cqspi->pdev;
>         struct device *dev = &pdev->dev;
> -       const struct cqspi_driver_platdata *ddata;
> -       struct spi_nor_hwcaps hwcaps;
> +       struct device_node *np = dev->of_node;
>         struct cqspi_flash_pdata *f_pdata;
> -       struct spi_nor *nor;
> -       struct mtd_info *mtd;
>         unsigned int cs;
> -       int i, ret;
> -
> -       ddata = of_device_get_match_data(dev);
> -       if (!ddata) {
> -               dev_err(dev, "Couldn't find driver data\n");
> -               return -EINVAL;
> -       }
> -       hwcaps.mask = ddata->hwcaps_mask;
> 
>         /* Get flash device data */
>         for_each_available_child_of_node(dev->of_node, np) {
> -               ret = of_property_read_u32(np, "reg", &cs);
> -               if (ret) {
> +               if (of_property_read_u32(np, "reg", &cs)) {
>                         dev_err(dev, "Couldn't determine chip select.\n");
> -                       goto err;
> +                       continue;

reg is mandatory, you should keep the behaviour as it was.

>                 }
> 
>                 if (cs >= CQSPI_MAX_CHIPSELECT) {
> -                       ret = -EINVAL;
>                         dev_err(dev, "Chip select %d out of range.\n", cs);
> -                       goto err;
> +                       continue;
>                 }
> 
>                 f_pdata = &cqspi->f_pdata[cs];
>                 f_pdata->cqspi = cqspi;
>                 f_pdata->cs = cs;
> 
> -               ret = cqspi_of_get_flash_pdata(pdev, f_pdata, np);
> -               if (ret)
> -                       goto err;
> -
> -               nor = &f_pdata->nor;
> -               mtd = &nor->mtd;
> -
> -               mtd->priv = nor;
> -
> -               nor->dev = dev;
> -               spi_nor_set_flash_node(nor, np);
> -               nor->priv = f_pdata;
> -               nor->controller_ops = &cqspi_controller_ops;
> -
> -               mtd->name = devm_kasprintf(dev, GFP_KERNEL, "%s.%d",
> -                                          dev_name(dev), cs);
> -               if (!mtd->name) {
> -                       ret = -ENOMEM;
> -                       goto err;
> -               }
> -
> -               ret = spi_nor_scan(nor, NULL, &hwcaps);
> -               if (ret)
> -                       goto err;
> -
> -               ret = mtd_device_register(mtd, NULL, 0);
> -               if (ret)
> -                       goto err;
> -
> -               f_pdata->registered = true;
> -
> -               if (mtd->size <= cqspi->ahb_size &&
> -                   !(ddata->quirks & CQSPI_DISABLE_DAC_MODE)) {
> -                       f_pdata->use_direct_mode = true;
> -                       dev_dbg(nor->dev, "using direct mode for %s\n",
> -                               mtd->name);
> -
> -                       if (!cqspi->rx_chan)
> -                               cqspi_request_mmap_dma(cqspi);
> -               }
> +               return cqspi_of_get_flash_pdata(pdev, f_pdata, np);

drop the return. you now parse just the first discovered flash, whereas before 
your changes we parsed all the described flashes.

>         }
> 
>         return 0;
> -
> -err:
> -       for (i = 0; i < CQSPI_MAX_CHIPSELECT; i++)
> -               if (cqspi->f_pdata[i].registered)
> -                       mtd_device_unregister(&cqspi->f_pdata[i].nor.mtd);
> -       return ret;
>  }
> 
>  static int cqspi_probe(struct platform_device *pdev)
>  {
> -       struct device_node *np = pdev->dev.of_node;
> +       const struct cqspi_driver_platdata *ddata;
> +       struct reset_control *rstc, *rstc_ocp;
>         struct device *dev = &pdev->dev;
> +       struct spi_master *master;
> +       struct resource *res_ahb;
>         struct cqspi_st *cqspi;
>         struct resource *res;
> -       struct resource *res_ahb;
> -       struct reset_control *rstc, *rstc_ocp;
> -       const struct cqspi_driver_platdata *ddata;
>         int ret;
>         int irq;
> 
> -       cqspi = devm_kzalloc(dev, sizeof(*cqspi), GFP_KERNEL);
> -       if (!cqspi)
> +       master = spi_alloc_master(&pdev->dev, sizeof(*cqspi));
> +       if (!master) {
> +               dev_err(&pdev->dev, "spi_alloc_master failed\n");
>                 return -ENOMEM;
> +       }
> +       master->mode_bits = SPI_RX_QUAD | SPI_RX_DUAL;
> +       master->mem_ops = &cqspi_mem_ops;
> +       master->dev.of_node = pdev->dev.of_node;
> +
> +       cqspi = spi_master_get_devdata(master);
> 
> -       mutex_init(&cqspi->bus_mutex);
>         cqspi->pdev = pdev;
> -       platform_set_drvdata(pdev, cqspi);
> 
>         /* Obtain configuration from OF. */
> -       ret = cqspi_of_get_pdata(pdev);
> +       ret = cqspi_of_get_pdata(cqspi);
>         if (ret) {

spi_controller_put() to not leak memory.

Cheers,
ta