From: Mark Brown <broonie@kernel.org>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org,
Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Subject: Re: [PATCH 4/5] spi: Check that Quad/Dual is half duplex
Date: Tue, 21 Jan 2014 18:21:30 +0000 [thread overview]
Message-ID: <20140121182130.GM17314@sirena.org.uk> (raw)
In-Reply-To: <1390317009-8292-4-git-send-email-geert@linux-m68k.org>
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On Tue, Jan 21, 2014 at 04:10:08PM +0100, Geert Uytterhoeven wrote:
> From: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
>
> Quad and Dual SPI Transfers use all available data lines (incl. MOSI/MISO),
> hence they must be half duplex. Add a check that verify that.
This is surprising to me - I had expected that there would be extra
signals that would be used for these modes, not that the opposite
direction data line would be one of the ones being reused. On the other
hand if this is what all the flash chips do then it would seem
reasonable that controllers do the same. Can you clarify please?
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next prev parent reply other threads:[~2014-01-21 18:21 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-21 15:10 [PATCH 1/5] spi: Spelling s/finised/finished/ Geert Uytterhoeven
2014-01-21 15:10 ` [PATCH v2 2/5] spi: Clarify transfer_one() w.r.t. spi_finalize_current_transfer() Geert Uytterhoeven
2014-01-21 18:12 ` Mark Brown
2014-01-21 15:10 ` [PATCH v2 3/5] spi: Correct set_cs() documentation Geert Uytterhoeven
2014-01-21 18:13 ` Mark Brown
2014-01-21 15:10 ` [PATCH 4/5] spi: Check that Quad/Dual is half duplex Geert Uytterhoeven
2014-01-21 18:21 ` Mark Brown [this message]
2014-01-21 20:06 ` Geert Uytterhoeven
2014-01-22 19:19 ` Gerhard Sittig
2014-01-22 20:26 ` Geert Uytterhoeven
2014-01-22 14:27 ` Geert Uytterhoeven
2014-01-21 15:10 ` [PATCH 5/5] spi: rspi: Document support for Renesas QSPI in Kconfig Geert Uytterhoeven
2014-01-21 18:23 ` Mark Brown
2014-01-21 18:12 ` [PATCH 1/5] spi: Spelling s/finised/finished/ Mark Brown
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