Re: [PATCH] mtd: spi-nor: cadence-quadspi: write upto 8-bytes data in STIG mode

[<Tudor.Ambarus@microchip.com>]

+ Vignesh

On 01/28/2019 07:02 AM, Purna Chandra Mandal wrote:
> cadence-quadspi controller allows upto eight bytes of data to
> be written in software Triggered Instruction generator (STIG) mode
> of operation. Lower 4 bytes are written through writedatalower and
> upper 4 bytes by writedataupper register.
> 
> This patch allows all the 8 bytes to be written.
> 
> Signed-off-by: Purna Chandra Mandal <purna.chandra.mandal@intel.com>

Looks good for me:
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>

Vignesh, can we have your R-b or T-b tag?

Cheers,
ta

> ---
> 
>  drivers/mtd/spi-nor/cadence-quadspi.c | 15 ++++++++++++---
>  1 file changed, 12 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c
> index 04cedd3a2bf6..7f78f9409ddd 100644
> --- a/drivers/mtd/spi-nor/cadence-quadspi.c
> +++ b/drivers/mtd/spi-nor/cadence-quadspi.c
> @@ -418,9 +418,10 @@ static int cqspi_command_write(struct spi_nor *nor, const u8 opcode,
>  	void __iomem *reg_base = cqspi->iobase;
>  	unsigned int reg;
>  	unsigned int data;
> +	u32 write_len;
>  	int ret;
>  
> -	if (n_tx > 4 || (n_tx && !txbuf)) {
> +	if (n_tx > CQSPI_STIG_DATA_LEN_MAX || (n_tx && !txbuf)) {
>  		dev_err(nor->dev,
>  			"Invalid input argument, cmdlen %d txbuf 0x%p\n",
>  			n_tx, txbuf);
> @@ -433,10 +434,18 @@ static int cqspi_command_write(struct spi_nor *nor, const u8 opcode,
>  		reg |= ((n_tx - 1) & CQSPI_REG_CMDCTRL_WR_BYTES_MASK)
>  			<< CQSPI_REG_CMDCTRL_WR_BYTES_LSB;
>  		data = 0;
> -		memcpy(&data, txbuf, n_tx);
> +		write_len = (n_tx > 4) ? 4 : n_tx;
> +		memcpy(&data, txbuf, write_len);
> +		txbuf += write_len;
>  		writel(data, reg_base + CQSPI_REG_CMDWRITEDATALOWER);
> -	}
>  
> +		if (n_tx > 4) {
> +			data = 0;
> +			write_len = n_tx - 4;
> +			memcpy(&data, txbuf, write_len);
> +			writel(data, reg_base + CQSPI_REG_CMDWRITEDATAUPPER);
> +		}
> +	}
>  	ret = cqspi_exec_flash_cmd(cqspi, reg);
>  	return ret;
>  }
>