From: Mark Brown <broonie@kernel.org>
To: "Mahapatra, Amit Kumar" <amit.kumar-mahapatra@amd.com>
Cc: Michal Simek <michal.simek@xilinx.com>,
Amit Kumar Mahapatra <amit.kumar-mahapatra@xilinx.com>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
"p.yadav@ti.com" <p.yadav@ti.com>,
"miquel.raynal@bootlin.com" <miquel.raynal@bootlin.com>,
"richard@nod.at" <richard@nod.at>,
"vigneshr@ti.com" <vigneshr@ti.com>,
"git@xilinx.com" <git@xilinx.com>,
"linux-spi@vger.kernel.org" <linux-spi@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"michael@walle.cc" <michael@walle.cc>,
"linux-mtd@lists.infradead.org" <linux-mtd@lists.infradead.org>,
"git (AMD-Xilinx)" <git@amd.com>
Subject: Re: [RFC PATCH 1/2] spi: Add multiple CS support for a single SPI device
Date: Fri, 15 Jul 2022 17:03:31 +0100 [thread overview]
Message-ID: <YtGP0+7TPGdcPTEM@sirena.org.uk> (raw)
In-Reply-To: <DM6PR12MB2809BA6D4F94EA59E76E6576DC8B9@DM6PR12MB2809.namprd12.prod.outlook.com>
[-- Attachment #1.1: Type: text/plain, Size: 869 bytes --]
On Fri, Jul 15, 2022 at 03:36:23PM +0000, Mahapatra, Amit Kumar wrote:
> Thank you for the clarification.
> As per my understanding we would not be needing a new DT
> property for expressing multi chip select support in the driver.
> We can use "num-cs" property of the spi controller for
> broadcasting multi chip select support of the driver.
> If "num-cs" value is greater than 1 then the driver can support
> multiple chip selects.
That's true in some sense but not in the sense of being actually able to
use more than one chip select for a single device. If the controller
hardware manages the chip selects it may not be physically possible for
it to control more than one chip select.
While it's not an issue for the bindings even hardware that can
physically do it is going to need a driver update (in the core for GPIO
stuff) to do so.
[-- Attachment #1.2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]
[-- Attachment #2: Type: text/plain, Size: 144 bytes --]
______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/
next prev parent reply other threads:[~2022-07-15 16:04 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-06 11:26 [RFC PATCH 0/2] spi: Add support for stacked/parallel memories Amit Kumar Mahapatra
2022-06-06 11:26 ` [RFC PATCH 1/2] spi: Add multiple CS support for a single SPI device Amit Kumar Mahapatra
2022-06-09 11:54 ` Mark Brown
2022-06-23 11:39 ` Mahapatra, Amit Kumar
2022-06-23 12:06 ` Mark Brown
2022-07-15 15:35 ` Mahapatra, Amit Kumar
2022-07-15 15:54 ` Mark Brown
2022-07-19 13:21 ` Mahapatra, Amit Kumar
2022-07-19 17:53 ` Mark Brown
2022-07-27 13:02 ` Mahapatra, Amit Kumar
2022-07-11 12:47 ` Michal Simek
2022-07-11 14:52 ` Mark Brown
2022-07-15 15:36 ` Mahapatra, Amit Kumar
2022-07-15 16:03 ` Mark Brown [this message]
2022-06-06 11:26 ` [RFC PATCH 2/2] mtd: spi-nor: Add support for stacked/parallel memories Amit Kumar Mahapatra
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YtGP0+7TPGdcPTEM@sirena.org.uk \
--to=broonie@kernel.org \
--cc=amit.kumar-mahapatra@amd.com \
--cc=amit.kumar-mahapatra@xilinx.com \
--cc=git@amd.com \
--cc=git@xilinx.com \
--cc=krzysztof.kozlowski+dt@linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mtd@lists.infradead.org \
--cc=linux-spi@vger.kernel.org \
--cc=michael@walle.cc \
--cc=michal.simek@xilinx.com \
--cc=miquel.raynal@bootlin.com \
--cc=p.yadav@ti.com \
--cc=richard@nod.at \
--cc=vigneshr@ti.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).