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