From: Marek Vasut <marek.vasut@gmail.com>
To: masonccyang@mxic.com.tw
Cc: bbrezillon@kernel.org, broonie@kernel.org,
Geert Uytterhoeven <geert+renesas@glider.be>,
Simon Horman <horms@verge.net.au>,
juliensu@mxic.com.tw, linux-kernel@vger.kernel.org,
linux-renesas-soc@vger.kernel.org, linux-spi@vger.kernel.org,
sergei.shtylyov@cogentembedded.com, zhengxunli@mxic.com.tw
Subject: Re: [PATCH v7 1/2] spi: Add Renesas R-Car Gen3 RPC-IF SPI controller driver
Date: Mon, 28 Jan 2019 12:03:00 +0100 [thread overview]
Message-ID: <2d762c16-d714-9171-9450-b6adf1a6509c@gmail.com> (raw)
In-Reply-To: <OFEAAE10B4.20C3E45D-ON48258390.0007CD37-48258390.0009066E@mxic.com.tw>
On 1/28/19 2:38 AM, masonccyang@mxic.com.tw wrote:
> Hi Marek,
Hi,
>> "Marek Vasut" <marek.vasut@gmail.com>
>> >> >> > +module_platform_driver(rpc_spi_driver);
>> >> >>
>> >> >> RPC is not a SPI controller, it's a SPI and HF controller.
>> >> >>
>> >> >> Also, how difficult will it be to add the HF support ?
>> >> >
>> >> > One of my customers needs RPC SPI driver for our company's
>> >> > Octal-Flash,MX25UW51245G.
>> >> > We don't have HF product and hope you could understanding.
>> >>
>> >> I am worried that when we need to add RPC HF support (which is what all
>> >> boards but the D3 Draak use), we will have to rewrite the entire driver
>> >> and/or convert it to MFD and that would be a tremendous
> undertaking. I'd
>> >> prefer to have the driver ready for the HF addition before it's
> accepted
>> >> upstream.
>> >>
>> >
>> > I think maybe your concerned would be happened only if HF driver
> goes with
>> > spi-mem layer.
>> >
>> > A comment for HF from Daniel Fishman. FYR.
>> >
>> > https://www.quora.com/What-is-a-hyper-flash-memory-and-how-is-it-
>> different-from-normal-flash-memory
>>
>> I have a decent idea what HF and SPI NOR are, since I wrote the RPC
>> driver for both HF and SPI mode for U-Boot (as I mentioned earlier).
>>
>> The HF in Linux would use the CFI NOR part of MTD framework. My concern
>> is that when we need to add HF support into this driver, this driver
>> will have to be basically rewritten, since the architecture won't allow
>> for that. I'd like to avoid that, since the majority of Gen3 boards,
>> expect for the D3 Draak, use RPC in HF mode.
>
> FYI~
>
> MX25UW51245g(64MByte Octa) S26KL512S(64MByte HF)
> 8 IO 8 IO
> 200MHz DDR@1.8v 166MHz DDR@1.8v
>
> support Read-while-write Not support
> good for OTA,etc
> powerful application
What does that mean ?
--
Best regards,
Marek Vasut
next prev parent reply other threads:[~2019-01-28 11:03 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-23 7:09 [PATCH v7 0/2] spi: Add Renesas R-Car Gen3 RPC-IF SPI driver Mason Yang
2019-01-23 7:09 ` [PATCH v7 1/2] spi: Add Renesas R-Car Gen3 RPC-IF SPI controller driver Mason Yang
2019-01-23 18:04 ` Sergei Shtylyov
[not found] ` <OFC86383C3.5347178A-ON4825838C.00093E95-4825838C.000B9D6F@mxic.com.tw>
2019-01-24 9:12 ` Geert Uytterhoeven
2019-01-24 11:27 ` Sergei Shtylyov
2019-01-24 11:27 ` Sergei Shtylyov
2019-01-24 1:51 ` Marek Vasut
[not found] ` <OF767ACC95.EECC73BE-ON4825838C.000BD6A3-4825838C.000D23A6@mxic.com.tw>
2019-01-24 3:13 ` Marek Vasut
[not found] ` <OF891E176A.614DBEEF-ON4825838C.0022D454-4825838C.002396ED@mxic.com.tw>
2019-01-26 9:41 ` Marek Vasut
[not found] ` <OFEAAE10B4.20C3E45D-ON48258390.0007CD37-48258390.0009066E@mxic.com.tw>
2019-01-28 11:03 ` Marek Vasut [this message]
[not found] ` <OF1DC7FF88.3574E5B9-ON48258391.000A5001-48258391.000D5DDE@mxic.com.tw>
2019-01-29 4:43 ` Marek Vasut
[not found] ` <OFA6EF1EB2.198B44D0-ON48258392.00099520-48258392.000D03A4@mxic.com.tw>
2019-01-30 7:15 ` Marek Vasut
2019-01-30 9:26 ` Boris Brezillon
2019-01-24 11:31 ` Sergei Shtylyov
2019-01-23 7:09 ` [PATCH v7 2/2] dt-bindings: spi: Document Renesas R-Car Gen3 RPC-IF controller bindings Mason Yang
2019-01-23 18:06 ` Sergei Shtylyov
[not found] ` <OF87800430.BAF731CA-ON4825838C.0006CCEE-4825838C.00092BDE@mxic.com.tw>
2019-01-24 8:16 ` Sergei Shtylyov
2019-01-24 1:53 ` Marek Vasut
[not found] ` <OFB904EE00.27B08F2C-ON4825838C.000D6846-4825838C.000E90F7@mxic.com.tw>
2019-01-24 9:06 ` Geert Uytterhoeven
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