| Message ID | 1453806725-4880-2-git-send-email-linus.walleij@linaro.org |
|---|---|
| State | Deferred |
| Headers | show |
On Tue, Jan 26, 2016 at 12:12:00PM +0100, Linus Walleij wrote: > The bindings for the "arm,versatile-flash" device was merged in > commit 3ba7222ac992d24d09ccd0b55940b54849eef752 > "arm/versatile: Add device tree support" but was never used > for anything. > > Versatile flash chips are actually just standard CFI chips, > but they have one or two bits in a system controller to control > VPP and write protection. Let's use this compatible string in > conjunction with "cfi-flash" to indicate that we have a > normal CFI flash with some extra Versatile-specific protection. > > Cc: devicetree@vger.kernel.org > Cc: Grant Likely <grant.likely@linaro.org> > Cc: Rob Herring <robh@kernel.org> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Mark Rutland <mark.rutland@arm.com> > Signed-off-by: Linus Walleij <linus.walleij@linaro.org> > --- > .../devicetree/bindings/mtd/arm-versatile.txt | 20 +++++++++++++++++++- > 1 file changed, 19 insertions(+), 1 deletion(-) Acked-by: Rob Herring <robh@kernel.org>
diff --git a/Documentation/devicetree/bindings/mtd/arm-versatile.txt b/Documentation/devicetree/bindings/mtd/arm-versatile.txt index beace4b89daa..4ec28796a3c0 100644 --- a/Documentation/devicetree/bindings/mtd/arm-versatile.txt +++ b/Documentation/devicetree/bindings/mtd/arm-versatile.txt @@ -1,8 +1,26 @@ Flash device on ARM Versatile board +These flash chips are found in the ARM reference designs like Integrator, +Versatile, RealView, Versatile Express etc. + +They are regular CFI compatible (Intel or AMD extended) flash chips with +some special write protect/VPP bits that can be controlled by the machine's +system controller. + Required properties: -- compatible : must be "arm,versatile-flash"; +- compatible : must be "arm,versatile-flash", "cfi-flash"; +- reg : memory address for the flash chip - bank-width : width in bytes of flash interface. +For the rest of the properties, see mtd-physmap.txt. + The device tree may optionally contain sub-nodes describing partitions of the address space. See partition.txt for more detail. + +Example: + +flash@34000000 { + compatible = "arm,versatile-flash", "cfi-flash"; + reg = <0x34000000 0x4000000>; + bank-width = <4>; +};
The bindings for the "arm,versatile-flash" device was merged in commit 3ba7222ac992d24d09ccd0b55940b54849eef752 "arm/versatile: Add device tree support" but was never used for anything. Versatile flash chips are actually just standard CFI chips, but they have one or two bits in a system controller to control VPP and write protection. Let's use this compatible string in conjunction with "cfi-flash" to indicate that we have a normal CFI flash with some extra Versatile-specific protection. Cc: devicetree@vger.kernel.org Cc: Grant Likely <grant.likely@linaro.org> Cc: Rob Herring <robh@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> --- .../devicetree/bindings/mtd/arm-versatile.txt | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-)