Re: [PATCH 2/2] mtd: make spinand driver usable without CONFIG_DM

On Sat, Jul 11, 2020 at 3:06 PM Mikhail Kshevetskiy mkshevetskiy@oktetlabs.ru wrote:

On Sat, 11 Jul 2020 14:16:23 +0530 Jagan Teki jagan@amarulasolutions.com wrote:

...

On Mon, Jun 22, 2020 at 9:25 PM Mikhail Kshevetskiy mikhail.kshevetskiy@oktetlabs.ru wrote:

...

From: Mikhail Kshevetskiy Mikhail.Kshevetskiy@oktetlabs.ru

Here is an example of spinand driver initialization without CONFIG_DM enabled:

void board_nand_init(void) { static struct spinand_device spinand; static struct mtd_info mtd; static struct spi_slave *slave; int ret;

    memset(&spinand, 0, sizeof(spinand));
    memset(&mtd, 0, sizeof(mtd));

    slave = spi_setup_slave(BUS, CS, MAX_HZ, MODE);
    if (!slave) {
            printf("SPI-NAND: Failed to set up SPI slave\n");
            return;
    }

    slave->mode |= (SPI_TX_BYTE | SPI_RX_SLOW);
    slave->max_read_size = SPI_MAX_READ_SIZE;
    slave->max_write_size = SPI_MAX_WRITE_SIZE;

    ret = spinand_probe_no_dm(&spinand, slave, &mtd);
    if (!ret)
            nand_register(0, &mtd);

}

Using of dual and quad wire transfer modes requires:

• dual/quad speed capable hardware (both controller and flash)
• physical presence of 4 data wires (quad mode only)
• spi controller driver MUST supports slave->mem_ops.exec_op() operations (spi_xfer() interface will suits for single speed data transfer mode only)

Signed-off-by: Mikhail Kshevetskiy Mikhail.Kshevetskiy@oktetlabs.ru

Now it's time for dm only code, better not come up with nondm anymore as possible, please.

Jagan.

I know about it. These patches were in the queue for upstreaming from the new year :-(

We are using 2010 and 2016 year based u-boot in our projects and due to some reasons it's not easy to switch it to DM build. This two patches helps us with backporting of spinand driver from upsteam u-boot. I think we are not an only users of old u-boot in the world, so it maybe helpful for other people as well.

Yes, I agree with this point in terms of MTD code is a concern. However, supporting nondm at this point look traversing in the reverse direction as per as U-Boot development is a concern. I can guarantee that the community is always helping to improve code if you wish to use/migrate the mainline at any point.

Just ignore these two patches if you think that NODM era is completely over.

Thanks.

Jagan.