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From: Schrempf Frieder <frieder.schrempf@kontron.De>
To: "linux-mtd@lists.infradead.org" <linux-mtd@lists.infradead.org>,
	"boris.brezillon@bootlin.com" <boris.brezillon@bootlin.com>,
	"linux-spi@vger.kernel.org" <linux-spi@vger.kernel.org>,
	Mark Brown <broonie@kernel.org>
Cc: "dwmw2@infradead.org" <dwmw2@infradead.org>,
	"computersforpeace@gmail.com" <computersforpeace@gmail.com>,
	"marek.vasut@gmail.com" <marek.vasut@gmail.com>,
	"richard@nod.at" <richard@nod.at>,
	"miquel.raynal@bootlin.com" <miquel.raynal@bootlin.com>,
	"david.wolfe@nxp.com" <david.wolfe@nxp.com>,
	"fabio.estevam@nxp.com" <fabio.estevam@nxp.com>,
	"prabhakar.kushwaha@nxp.com" <prabhakar.kushwaha@nxp.com>,
	"yogeshnarayan.gaur@nxp.com" <yogeshnarayan.gaur@nxp.com>,
	"han.xu@nxp.com" <han.xu@nxp.com>,
	"shawnguo@kernel.org" <shawnguo@kernel.org>,
	Schrempf Frieder <frieder.schrempf@kontron.De>,
	Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: [PATCH v5 5/9] dt-bindings: spi: Adjust the bindings for the FSL QSPI driver
Date: Tue, 13 Nov 2018 13:47:37 +0000	[thread overview]
Message-ID: <1542116782-13118-6-git-send-email-frieder.schrempf@kontron.de> (raw)
In-Reply-To: <1542116782-13118-1-git-send-email-frieder.schrempf@kontron.de>

Adjust the documentation of the new SPI memory interface based
driver to reflect the new drivers settings.

The "old" driver was using the "fsl,qspi-has-second-chip" property to
select one of two dual chip setups (two chips on one bus or two chips
on separate buses). And it used the order in which the subnodes are
defined in the dt to select the CS, the chip is connected to.

Both methods are wrong and in fact the "reg" property should be used to
determine which bus and CS a chip is connected to. This also enables us
to use different setups than just single chip, or symmetric dual chip.

So the porting of the driver from the MTD to the SPI framework actually
enforces the use of the "reg" properties and makes
"fsl,qspi-has-second-chip" superfluous.

As all boards that have "fsl,qspi-has-second-chip" set, also have
correct "reg" properties, the removal of this property shouldn't lead to
any incompatibilities.

The only compatibility issues I can see are with imx6sx-sdb.dts and
imx6sx-sdb-reva.dts, which have their reg properties set incorrectly
(see explanation here: [2]), all other boards should stay compatible.

Also the "big-endian" flag was removed, as this setting is now selected
by the driver, depending on which SoC is in use.

[2] https://patchwork.ozlabs.org/patch/922817/#1925445

Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
---
 .../devicetree/bindings/spi/spi-fsl-qspi.txt      | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/Documentation/devicetree/bindings/spi/spi-fsl-qspi.txt b/Documentation/devicetree/bindings/spi/spi-fsl-qspi.txt
index 483e9cf..e8f1d62 100644
--- a/Documentation/devicetree/bindings/spi/spi-fsl-qspi.txt
+++ b/Documentation/devicetree/bindings/spi/spi-fsl-qspi.txt
@@ -14,15 +14,13 @@ Required properties:
   - clocks : The clocks needed by the QuadSPI controller
   - clock-names : Should contain the name of the clocks: "qspi_en" and "qspi".
 
-Optional properties:
-  - fsl,qspi-has-second-chip: The controller has two buses, bus A and bus B.
-                              Each bus can be connected with two NOR flashes.
-			      Most of the time, each bus only has one NOR flash
-			      connected, this is the default case.
-			      But if there are two NOR flashes connected to the
-			      bus, you should enable this property.
-			      (Please check the board's schematic.)
-  - big-endian : That means the IP register is big endian
+Required SPI slave node properties:
+  - reg: There are two buses (A and B) with two chip selects each.
+	 This encodes to which bus and CS the flash is connected:
+		<0>: Bus A, CS 0
+		<1>: Bus A, CS 1
+		<2>: Bus B, CS 0
+		<3>: Bus B, CS 1
 
 Example:
 
@@ -40,7 +38,7 @@ qspi0: quadspi@40044000 {
 	};
 };
 
-Example showing the usage of two SPI NOR devices:
+Example showing the usage of two SPI NOR devices on bus A:
 
 &qspi2 {
 	pinctrl-names = "default";
-- 
2.7.4

  parent reply	other threads:[~2018-11-13 13:47 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-13 13:47 [PATCH v5 0/9] Port the FSL QSPI driver to the SPI framework Schrempf Frieder
2018-11-13 13:47 ` [PATCH v5 1/9] ARM: dts: Reflect change of FSL QSPI driver and remove unused properties Schrempf Frieder
2018-11-13 13:47 ` [PATCH v5 2/9] arm64: " Schrempf Frieder
2018-11-13 13:47 ` [PATCH v5 3/9] spi: Add a driver for the Freescale/NXP QuadSPI controller Schrempf Frieder
2018-11-14  8:39   ` Yogesh Narayan Gaur
2018-11-14  8:50     ` Schrempf Frieder
2018-11-14  9:03       ` Schrempf Frieder
2018-11-14 10:43         ` Yogesh Narayan Gaur
2018-11-14 10:46           ` Boris Brezillon
2018-11-14 11:07           ` Schrempf Frieder
2018-11-15  6:22             ` Yogesh Narayan Gaur
2018-11-15 11:43               ` Schrempf Frieder
2018-11-15 13:12                 ` Boris Brezillon
2018-11-15 14:01                   ` Schrempf Frieder
2018-11-16  5:41                     ` Yogesh Narayan Gaur
2018-11-16  9:42                       ` Schrempf Frieder
2018-11-16  9:46                         ` Yogesh Narayan Gaur
2018-11-16 10:10                           ` Schrempf Frieder
2018-11-13 13:47 ` [PATCH v5 4/9] dt-bindings: spi: Move the bindings for the FSL QSPI driver Schrempf Frieder
2018-11-16 22:59   ` Rob Herring
2018-11-13 13:47 ` Schrempf Frieder [this message]
2018-11-16 22:59   ` [PATCH v5 5/9] dt-bindings: spi: Adjust " Rob Herring
2018-11-13 13:47 ` [PATCH v5 6/9] mtd: fsl-quadspi: Remove the driver as it was replaced by spi-fsl-qspi.c Schrempf Frieder
2018-11-13 13:47 ` [PATCH v5 7/9] ARM: dts: ls1021a: Remove fsl,qspi-has-second-chip as it is not used Schrempf Frieder
2018-11-13 13:47 ` [PATCH v5 8/9] ARM64: dts: ls1046a: " Schrempf Frieder
2018-11-13 13:48 ` [PATCH v5 9/9] MAINTAINERS: Move the Freescale QSPI driver to the SPI framework Schrempf Frieder

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