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

[Mandal, Purna Chandra]

On 21-Jan-19 3:07 PM, Tudor.Ambarus@xxxxxxxxxxxxx wrote:
> Hi, Purna,
>
> On 12/14/2018 04:15 AM, Purna Chandra Mandal wrote:
> > cadence-quadspi controller allows upto eight bytes of data to be transferred
> > in software Triggered Instruction generator (STIG) mode of operation. Lower
> > 4 bytes are written through writedatalower and upper 4 bytes by
> > writedataupper register.
>
> Is this supported by all versions of the IP?
Yes, it is supported on all versions of IP.
> > This patch allows all the 8 bytes to be written.
> >
> > Signed-off-by: Purna Chandra Mandal <purna.chandra.mandal@xxxxxxxxx>
> > ---
> >
> >   drivers/mtd/spi-nor/cadence-quadspi.c | 9 +++++++--
> >   1 file changed, 7 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c
> > index 04cedd3a2bf6..990934387fea 100644
> > --- a/drivers/mtd/spi-nor/cadence-quadspi.c
> > +++ b/drivers/mtd/spi-nor/cadence-quadspi.c
> > @@ -420,7 +420,7 @@ static int cqspi_command_write(struct spi_nor *nor, const u8 opcode,
> >   	unsigned int data;
>
> I know that this is not your change, but data should be u32 and not unsigned
> int. reg too ... probably one should submit a patch to change this, I see that
> the same error is done in cqspi_command_read().
ack. will be done in separate patch.
> >   	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);
> > @@ -435,8 +435,13 @@ static int cqspi_command_write(struct spi_nor *nor, const u8 opcode,
> >   		data = 0;>  		memcpy(&data, txbuf, n_tx);
>
> You should limit what is copied in data, similar to what is done in
> cqspi_command_read():
>
> write_len = (n_tx > 4) ? 4 : n_tx;
> memcpy(&data, txbuf, write_len);
> txbuf += write_len;
ack.
> >   		writel(data, reg_base + CQSPI_REG_CMDWRITEDATALOWER);
> > -	}
> >   
> > +		if (n_tx > 4) {
> > +			data = 0;
> and then:
> write_len = n_tx - 4;
> memcpy(&data, txbuf, write_len);
ack.
> Cheers,
> ta
>
> > +			memcpy(&data, txbuf + 4, n_tx - 4);
> > +			writel(data, reg_base + CQSPI_REG_CMDWRITEDATAUPPER);
> > +		}
> > +	}
> >   	ret = cqspi_exec_flash_cmd(cqspi, reg);
> >   	return ret;
> >   }