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Groups > linux.kernel > #1736549
| From | Masahiro Yamada <yamada.masahiro@socionext.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH] dt-bindings: nand: denali: reduce the register space in the example |
| Date | 2017-09-21 13:20 +0200 |
| Message-ID | <us7Gq-gp-23@gated-at.bofh.it> (permalink) |
| References | (1 earlier) <upxnI-2uK-19@gated-at.bofh.it> <upxxo-2xM-15@gated-at.bofh.it> <upyjM-357-15@gated-at.bofh.it> <us2dI-4YL-3@gated-at.bofh.it> <us2Qq-5sH-13@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
2017-09-21 15:09 GMT+09:00 Oleksij Rempel <ore@pengutronix.de>: > Hi, > > On 21.09.2017 07:26, Masahiro Yamada wrote: >> >> Hi. > > > ...... > >>> Hm.. according to >>> >>> https://www.altera.com/en_US/pdfs/literature/hb/cyclone-v/cyclone5_handbook.pdf >>> Table 13-18: NAND Controller Module Data Space Address Range >>> >>> Module Instance Start Address End Address >>> NAND_DATA 0xFF900000 0xFF9FFFFF >>> >>> So <0xff900000 0x100000> seems to be a proper value. >>> >> >> The Alrera's SOCFPGA document describes so. >> It is up to each SoC vendor how to describe the register space. >> >> I am focusing on the Denali IP >> because this IP is used among several SoCs. >> >> >> >> You can see the peripheral region map >> starting at page 1-18 of the document you referred to: >> >> Slave ID Description Base Addr Size >> --------------------------------------------------------------- >> L3REGS L3 interconnect GPV 0xFF800000 1 MB >> NANDDATA NAND flash controller data 0xFF900000 64 KB >> QSPIDATA Quad SPI flash data 0xFFA00000 1 MB >> >> (In the doc, the base is described as 0xFFB900000, but this is >> apparently a typo.) >> >> >> The rationale of the "End Address 0xFF9FFFFF" of NAND_DATA >> is the fact that the base address of the next peripheral (QSPIDATA) is >> 0xFFA00000. >> >> >> >> >> One more, if you look at the next page, >> >> Slave ID Description Base Addr Size >> --------------------------------------------------------------- >> NANDREGS NAND flash controller registers 0xFFB80000 64 KB >> FPGAMGRDATA FPGA manager configuration data 0xFFB90000 4 KB >> >> >> The size of NAND register space is described as 64KB, >> but the rationale is just the start of the next peripheral is 0xFFB90000. >> >> (0xFFB90000 - 0xFFB80000 = 0x10000 = 64KB) >> >> >> >> Altera apparently reserved address space just for the purpose >> of matching the end address to the base address of the next peripheral. >> >> >> That means, this document specifies address region >> much bigger than the IP actually provides. >> >> >> If you look at page 13-6, there are only two registers >> in NANDDATA space. >> >> Table 13-4: Register Map for Indexed Addressing >> Control 0x0 >> Data 0x10 >> >> >> >> For NANDREGS, in page 13-106, the following is the last register >> in the NANDREGS space. >> >> lun_status_cmd >> Offset 0x7A0 >> >> Obviously, 0x1000 (4KB) is enough for NANDREGS. >> >> To conclude this, this binding document was written >> based on the Altera's SOCFPGA specification. >> >> Altera specifies the region size >> so that end address matches to the base of the next peripheral. >> This is just a matter of SOCFPGA address mapping. >> >> In my opinion, the binding document should not be oriented >> to a particular SoC, which is not true for other SoCs. > > ok. Thank you for detailed response. BTW, I am not forcing you to change the SOCFPGA DTS. It is up to you and Dihn whether change it or not. I do not have any SOCFPGA board. -- Best Regards Masahiro Yamada
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[PATCH] dt-bindings: nand: denali: reduce the register space in the example Masahiro Yamada <yamada.masahiro@socionext.com> - 2017-09-14 09:30 +0200
Re: [PATCH] dt-bindings: nand: denali: reduce the register space in the example Oleksij Rempel <ore@pengutronix.de> - 2017-09-14 10:10 +0200
Re: [PATCH] dt-bindings: nand: denali: reduce the register space in the example Masahiro Yamada <yamada.masahiro@socionext.com> - 2017-09-14 10:20 +0200
Re: [PATCH] dt-bindings: nand: denali: reduce the register space in the example Oleksij Rempel <ore@pengutronix.de> - 2017-09-14 11:10 +0200
Re: [PATCH] dt-bindings: nand: denali: reduce the register space in the example Masahiro Yamada <yamada.masahiro@socionext.com> - 2017-09-21 07:30 +0200
Re: [PATCH] dt-bindings: nand: denali: reduce the register space in the example Oleksij Rempel <ore@pengutronix.de> - 2017-09-21 08:10 +0200
Re: [PATCH] dt-bindings: nand: denali: reduce the register space in the example Masahiro Yamada <yamada.masahiro@socionext.com> - 2017-09-21 13:20 +0200
Re: [PATCH] dt-bindings: nand: denali: reduce the register space in the example Rob Herring <robh@kernel.org> - 2017-09-22 01:00 +0200
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