From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven A. Falco Date: Tue, 09 Dec 2008 15:38:55 -0500 Subject: [U-Boot] [PATCH v3 2/2] ppc4xx: Add PPC4xx SPI helpers to Sequoia In-Reply-To: <493EC2EC.4050602@gmail.com> References: <493E9C46.8000101@harris.com> <493EA876.7090008@gmail.com> <20081209185341.71DAD834B020@gemini.denx.de> <493EC2EC.4050602@gmail.com> Message-ID: <493ED75F.9040308@harris.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Ben Warren wrote: > > Hi Wolfgang, > > Wolfgang Denk wrote: >> Dear Ben Warren, >> >> In message <493EA876.7090008@gmail.com> you wrote: >> >>> Why not enable this feature on Sequoia? Wolfgang's argument for >>> keeping the patch out then goes away. IMHO, eval boards should have >>> as many options enabled by default as possible, and the user then has >>> the option to opt out. >>> >> >> But there is not a single SPI device on the Sequoia board, and if you >> attach one, you have to write driver code for it that implements the >> chip select handling and the specific device protocol. We would have >> a driver included, without any "users" (code that actually calls >> these functions). >> >> > Sure. Ignorant assumption on my part that the eval board had something > like a SPI EEPROM, but it looks like there's just a header. In that > case, the only advantage to including it is to ensure the driver keeps > up with any API changes. >> In other words, this driver is a prerequisite for other SPI device >> drivers that might follow later, but as is, it's just a waste of >> memory. >> >> It would just waste memory to enable it. >> >> > OK, but who cares about memory on an evaluation board? Their entire > raison-d'etre is to serve as a starting point for custom boards. I know > if I was building a board with this CPU and planned on using SPI, it > would be much nicer if the driver was included than having to search the > message boards. Just my 2c. I agree with this position. I use U-Boot for two purposes - booting a kernel, and experimenting with hardware. Given that I am currently in the design phase of a project, I am prototyping things on an evaluation board, to see what works and what doesn't. Having U-Boot support all the interfaces of a SOC like the PPC440EPx is very useful to me. Much easier and quicker to do prototyping in U-Boot than in Linux. But again, you guys can decide the philosophical issues. I'm just the code monkey... Steve >> Best regards, >> >> Wolfgang Denk >> >> > regards, > Ben >