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.amba...@microchip.com 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.man...@intel.com>
---

  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;
  }