[PATCH 02/47] mtd: nand: stm_nand_bch: provide Device Tree documentation
lee.jones at linaro.org
Fri May 23 03:21:51 PDT 2014
> >This is where we describe the different new and generic options used by
> >the ST BCH driver.
> >Cc: devicetree at vger.kernel.org
> >Signed-off-by: Lee Jones <lee.jones at linaro.org>
> > Documentation/devicetree/bindings/mtd/stm-nand.txt | 123 +++++++++++++++++++++
> > 1 file changed, 123 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/mtd/stm-nand.txt
> >diff --git a/Documentation/devicetree/bindings/mtd/stm-nand.txt
> >new file mode 100644
> >index 0000000..9f9325f
> >--- /dev/null
> >+++ b/Documentation/devicetree/bindings/mtd/stm-nand.txt
> >@@ -0,0 +1,123 @@
> >+STM BCH NAND Support
> >+Required properties:
> >+- compatible : Should be "st,nand-bch"
> >+- reg : Should contain register's location and length
> >+- reg-names : "nand_mem" - NAND Controller register map
> >+ "nand_dma" - BCH Controller DMA configuration map
> >+- interrupts : Interrupt number
> >+- interrupt-names : "nand_irq" - NAND Controller IRQ
> >+- st,nand-banks : Subnode representing one or more "banks" of NAND
> >+ Flash, connected to an STM NAND Controller (see
> >+ description below).
> >+- nand-ecc-strength : Generic NAND property (See mtd/nand.txt)
> >+- st,bch-bitflip-threshold
> >+ : The threshold at which the number of corrected bit-
> >+ flips per sector is deemed to have reached an
> >+ excessive level (triggers '-EUCLEAN' to be returned
> >+ to the caller). The value should be in the range 1
> >+ to <ecc-strength> where <ecc-strength> is 18 or 30,
> >+ depending on the BCH ECC mode in operation. A value
> >+ of 0, or if left unspecified, is interpreted by the
> >+ driver as <ecc-strength>.
> Please drop this one as discussed in other thread that bitflip_threshold
> does not qualify as DT binding (as it's not a hardware or const parameter).
> >+Properties describing Bank of NAND Flash ("st,nand-banks"):
> >+- st,nand-csn : Chip select associated with the Bank.
> >+- st,nand-timing-spec : [Optional] NAND Device Timing Data. All times
> >+ expressed in ns, except where stated otherwise:
> I think DT maintainers don't prefer NAND timings being passed by DT,
> Instead they want it parsed from ONFI.
> Refer comments by 'Rob Herring <robherring2 at gmail.com>' on
> [PATCH RFC 1/3] Devicetree: Add pl353 smc controller devicetree binding information
> >+Note, during initialisation, the NAND Controller timing registers are configured
> >+according to one of the following methods, in order of precedence:
> >+ 1. Configuration based on "st,nand_timing_spec" if supplied.
> Not sure if this mode is really required, as almost all devices are ONFI compliant.
> Please check with 'Rob Herring <robherring2 at gmail.com>'
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