Hi all, Since the framework is named spi-nor, what about spi-nor-4byte-opcodes? Is it okay for everyone? It would follow the same pattern as spi-max-frequency which applies to all SPI devices. Best regards, Cyrille Le 23/03/2016 16:08, Cyrille Pitchen a écrit : > Hi Rob, > > sorry I've sent v3 at the same time as you answered to v2. > I'll take your comments into account for v4. > > Brian, any preference between 4byte-opcodes or m25p-4byte-opcodes? > > Best regards, > > Cyrille > > Le 23/03/2016 13:49, Rob Herring a écrit : >> On Tue, Mar 22, 2016 at 10:13 AM, Cyrille Pitchen >> <cyrille.pitchen@xxxxxxxxx> wrote: >>> This patch adds a new optional DT property which enables an alternative >>> way of supporting memory size above 16MiB (128Mib). This new mechanism >>> translates the regular 3byte-address op codes into their 4byte-address >>> version whereas the old/default mecanism makes the SPI memory enter its >>> 4byte-address mode, which has annoying side effects for early bootloaders. >>> >>> We cannot discover at run time whether the SPI NOR memory supports the >>> 4byte-address op codes. For instance both Macronix MX25L25635E and >>> MX25L25673G share the same JEDEC ID (C22019 without any extension byte). >>> However the first one doesn't support 4byte-address op codes whereas the >>> second one does. >>> >>> Signed-off-by: Cyrille Pitchen <cyrille.pitchen@xxxxxxxxx> >>> --- >>> Documentation/devicetree/bindings/mtd/jedec,spi-nor.txt | 11 +++++++++++ >>> 1 file changed, 11 insertions(+) >>> >>> diff --git a/Documentation/devicetree/bindings/mtd/jedec,spi-nor.txt b/Documentation/devicetree/bindings/mtd/jedec,spi-nor.txt >>> index 2c91c03e7eb0..8be610482089 100644 >>> --- a/Documentation/devicetree/bindings/mtd/jedec,spi-nor.txt >>> +++ b/Documentation/devicetree/bindings/mtd/jedec,spi-nor.txt >>> @@ -66,6 +66,17 @@ Optional properties: >>> Refer to your chips' datasheet to check if this is supported >>> by your chip. >>> >>> +- m25p,4byte-opcodes: For memory size above 16MiB (128Mib), use the dedicated >> >> m25p is not a vendor. So drop it or m25p-4byte-opcodes. >> >>> + 4byte-address opcodes instead of entering the 4byte >>> + address mode. This mode changes the internal state of the >>> + chip so may conflict with some early boot loaders, which >>> + expect to use the regular (Fast) Read opcodes with 3byte >>> + address. >>> + However 4byte-address opcodes are not supported by all >>> + chips and support for them can not be detected at runtime. >> >> s/can not/cannot/ >> >>> + Refer to you chip's datasheet to check if this is >>> + supported by your chip. >>> + >>> Example: >>> >>> flash: m25p80@0 { >>> -- >>> 1.8.2.2 >>> > -- 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