HI Jagan,
On 2015年11月07日 20:35, Jagan Teki wrote:
It seems we are working toward the same direction. :)
Sorry, I couldn't understand this looks we're in different direction.
Let me explain what I thought about mtd_info usage. udevice should be
part of underlying flash structure's like cfi, nand and spi_flash and
mtd_info should be used for it's core api's like _erase. _read and
_write and underlying driver will use their global structure that
include's mtd and udevice as a function pointer like this.
Please see v5 of this patch and v3 of altera qspi.
The uclass priv of mtd class is an auto-allocated mtd_info. The
spi_flash_priv includes both mtd_info and spi_flash. So the only
difference is the spi_flash. This is because cfi uses struct flash,
while spi flash uses struct spi_flash. So it is better to leave the
struct flash to driver allocation.
The mtd->priv points to struct spi_flash for spi flash, and points to
struct flash for cfi flash. It serves the same purpose.
The struct flash has *mtd. The struct spi_flash has *mtd, too.
I added struct udevice *dev to mtd_info. The struct spi_flash has *dev,
but struct flash has not.
struct spi_flash {
struct mtd_info *info;
struct udevice *device;
}
struct flash {
...
struct mtd_info *info;
}
struct spi_flash_priv {
struct spi_flash flash;
struct mtd_info mtd;
};
Simply,
struct mtd_info.
static int spi_flash_std_probe(struct udevice *dev)
{
struct spi_flash_priv *priv = dev_get_uclass_priv(dev);
struct spi_slave *spi = dev_get_parent_priv(dev);
struct spi_flash *flash;
int ret;
flash = &priv->flash;
flash->mtd = &priv->mtd;
mtd = dev_get_uclass_priv(dev);
flash->mtd = mtd;
flash->spi = spi;
flash->priv = priv;
priv->mtd.priv = flash;
flash->dev = dev;
mtd->priv = flash;
mtd->dev = dev;
flash->mtd->dev is the same as spi's flash->dev
}
U_BOOT_DRIVER(spi_flash_std) = {
.name = "spi_flash_std",
.id = UCLASS_SPI_FLASH,
.of_match = spi_flash_std_ids,
.probe = spi_flash_std_probe,
.priv_auto_alloc_size = sizeof(struct spi_flash_priv),
};
This is the way I have implemented mtd on spi-flash[1] [2]
[1] https://patchwork.ozlabs.org/patch/529397/
[2] https://patchwork.ozlabs.org/patch/529399/
Please explain how this related your approach of adding udevice to mtd.
The flash ops which u-boot commands calls are built upon mtd ops.
eg,
write_buff()
{
mtd_write();
}
flash_erase()
{
mtd_erase();
}
Please let me know what do you think. Thanks. :)
Best regards,
Thomas
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