[PATCH 3/4] mtd/fpga: add fpga directory to mtd (with Cyclone 10)

[Ulf Samuelsson]

Den 2023-02-12 kl. 20:31, skrev Marek Vasut:
 > On 2/11/23 11:07, u-boot at emagii.com wrote:
 >
 > [...]
 >
 >> +static int cyc10_write(struct mtd_info *mtd, loff_t to, size_t len,
 >> +                 size_t *retlen, const u_char *buf)
 >> +{
 >> +    struct udevice *dev = mtd->dev;
 >> +    struct spi_slave *slave = dev_get_parent_priv(dev);
 >> +    struct cyc10_plat *fpga = dev_get_plat(dev);
 >> +    int ret;
 >
 > Do I read this right, that the 'write' callback is the only one doing
 > meaningful work, all the other callbacks are just empty stubs ?
 > Yes, you cannot read back the configuration data.


 > Why not update drivers/fpga/cyclon2.c which is Passive Serial
 > implementation already present in U-Boot for Altera Cyclone II FPGA ,
 > with Cyclone 10 FPGA support ? I believe the PS protocol changed very
 > little.
Since the MTD command set is enough to configure the FPGA, the FPGA 
commands can be removed from the build. The FPGA command set requires 
you to supply addresses, but the MTD command set uses devices.

So:
* Smaller U-Boot image
* Simplified user interface.
* The FPGA is an SPI peripheral, so why not add it to the SPI part of 
the device tree?

Best Regards
Ulf Samuelsson

 >
 > [...]