Dear Mark Brown, > On Thu, Aug 22, 2013 at 12:34:53PM -0700, Brian Norris wrote: > > On Mon, Aug 19, 2013 at 12:10:01PM +0800, Huang Shijie wrote: > > > +- m25p,quad-read : Use the "quad read" opcode to read data from the > > > chip instead + of the usual "read" opcode. This > > > opcode is not supported by + all chips and support > > > for it can not be detected at runtime. + Refer to > > > your chips' datasheet to check if this is supported + > > > by your chip. > > > > Why can't this be detected at runtime? We added a "no fast read" flag to > > the device table, so why not "dual/quad mode supported"? And believe it > > or not, not all m25p80 users have device tree. So it isn't very logical > > to tie this support to device-tree only. > > There needs to be some way of saying if the additional data lines are > actually wired up or not; it could be a negative property (flagging if > the lines are not present) but that runs the risk of breaking systems > if a driver acquires the ability to support extra data lines but a > system doesn't have it. > > This should be a generic property for all quad devices to use, though, > since the same thing applies everywhere. Full ACK, "m25p,dual-read" and "m25p,quad-read" sound like a good prop names? Best regards, Marek Vasut -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html