Re: [PATCH] spi/spi-altera: Allow to explicitely override bus number via dts
From: Frederic LAMBERT <hidden>
Date: 2012-02-01 14:53:00
Also in:
linux-spi
quoted
Good question. I have a nvSRAM that I access using the AT25 driver, and I don't know how access it without its /sys/bus/ name. If there is another way, it is worse to consider it.For this I'd expect the application to be able to enumerate all the SPI devices and offer the user a selection of those with the appropriate driver bound (though I can see that simple scripts might not have bothered).
??? I wrote a piece of code that uses this nvSRAM as a persistent storage. This runs in a softcore embedded in an FPGA, in an equipment. The PC version of this application uses a simple file to emulate this behavior. The simulated version, using an x86 port embedded in a VirtualBox uses a piece of virtual disk with /dev/sdb. To sumarize, I have a same code that works for the 3 architecture, the single difference being in the device name: /sys/proc/spi/drivers/at25/spi0.0/eeprom for Nios2 dataBase.dat on Linux /dev/sdb on the Virtual Machine Why should I have to break that, which work nice, to use a bus enumeration which would be specific to the real hardware version, because I'm using a new tools, DTS, which is supposed to simplify my life. Sorry to insist, but this incapacity to set the bus number is a *real* regression (for me). I know I could use the name chosen by the kernel (it mus be something like /sys/.../spi253.0/...), but I have no control on it. If tomorrow someone changes something in the spi bus number definition, a kernel upgrade will have an impact on the user stuff... ------------------------------------------------------------------------------ Keep Your Developer Skills Current with LearnDevNow! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-d2d