2013-09-18 10:16:10

by Hongbo Zhang

[permalink] [raw]
Subject: [PATCH v10 0/3] DMA: Freescale: Add support for 8-channel DMA engine

From: Hongbo Zhang <[email protected]>

Hi DMA and DT maintainers, please have a look at these V10 patches.

Freescale QorIQ T4 and B4 introduce new 8-channel DMA engines, this patch set
adds support this DMA engine.

V9->V10 changes:
- update binding description text, mainly about the reg property and also Elo3
DMA controller specification

V8->V9 changes:
- add "Acked-by: Mark Rutland <[email protected]>" into patch [1/3]
- update reg entry <0x100300 0x4 0x100600 0x4> to two seperate ones
<0x100300 0x4>, <0x100600 0x4> in patch [2/3]
- and also use "QorIQ Elo3 DMA" to mention previous "QorIQ DMA" in [2/3]

V7->V8 changes:
- change the word "mapping" to "specifier" for reg and interrupts description

V6->V7 changes:
- only remove unnecessary "CHIP-dma" explanations in [1/3]

V5->V6 changes:
- minor updates of descriptions in binding document and Kconfig
- remove [4/4], that should be another patch in future

V4->V5 changes:
- update description in the dt binding document, to make it more resonable
- add new patch [4/4] to eliminate a compiling warning which already exists
for a long time

V3->V4 changes:
- introduce new patch [1/3] to revise the legacy dma binding document
- and then add new paragraph to describe new dt node binding in [2/3]
- rebase to latest kernel v3.11-rc1

V2->V3 changes:
- edit Documentation/devicetree/bindings/powerpc/fsl/dma.txt
- edit text string in Kconfig and the driver files, using "elo series" to
mention all the current "elo*"

V1->V2 changes:
- removed the codes handling the register dgsr1, since it isn't used currently
- renamed the DMA DT compatible to "fsl,elo3-dma"
- renamed the new dts files to "elo3-dma-<n>.dtsi"

Hongbo Zhang (3):
DMA: Freescale: revise device tree binding document
DMA: Freescale: Add new 8-channel DMA engine device tree nodes
DMA: Freescale: update driver to support 8-channel DMA engine

.../devicetree/bindings/powerpc/fsl/dma.txt | 137 ++++++++++++++------
arch/powerpc/boot/dts/fsl/b4si-post.dtsi | 4 +-
arch/powerpc/boot/dts/fsl/elo3-dma-0.dtsi | 82 ++++++++++++
arch/powerpc/boot/dts/fsl/elo3-dma-1.dtsi | 82 ++++++++++++
arch/powerpc/boot/dts/fsl/t4240si-post.dtsi | 4 +-
drivers/dma/Kconfig | 9 +-
drivers/dma/fsldma.c | 9 +-
drivers/dma/fsldma.h | 2 +-
8 files changed, 280 insertions(+), 49 deletions(-)
create mode 100644 arch/powerpc/boot/dts/fsl/elo3-dma-0.dtsi
create mode 100644 arch/powerpc/boot/dts/fsl/elo3-dma-1.dtsi

--
1.7.9.5



2013-09-18 10:16:16

by Hongbo Zhang

[permalink] [raw]
Subject: [PATCH v10 1/3] DMA: Freescale: revise device tree binding document

From: Hongbo Zhang <[email protected]>

This patch updates the discription of each type of DMA controller and its
channels, it is preparation for adding another new DMA controller binding, it
also fixes some defects of indent for text alignment at the same time.

Signed-off-by: Hongbo Zhang <[email protected]>
Acked-by: Mark Rutland <[email protected]>
---
.../devicetree/bindings/powerpc/fsl/dma.txt | 68 +++++++++-----------
1 file changed, 31 insertions(+), 37 deletions(-)

diff --git a/Documentation/devicetree/bindings/powerpc/fsl/dma.txt b/Documentation/devicetree/bindings/powerpc/fsl/dma.txt
index 2a4b4bc..0584168 100644
--- a/Documentation/devicetree/bindings/powerpc/fsl/dma.txt
+++ b/Documentation/devicetree/bindings/powerpc/fsl/dma.txt
@@ -1,33 +1,30 @@
-* Freescale 83xx DMA Controller
+* Freescale DMA Controllers

-Freescale PowerPC 83xx have on chip general purpose DMA controllers.
+** Freescale Elo DMA Controller
+ This is a little-endian 4-channel DMA controller, used in Freescale mpc83xx
+ series chips such as mpc8315, mpc8349, mpc8379 etc.

Required properties:

-- compatible : compatible list, contains 2 entries, first is
- "fsl,CHIP-dma", where CHIP is the processor
- (mpc8349, mpc8360, etc.) and the second is
- "fsl,elo-dma"
-- reg : <registers mapping for DMA general status reg>
-- ranges : Should be defined as specified in 1) to describe the
- DMA controller channels.
+- compatible : must include "fsl,elo-dma"
+- reg : DMA General Status Register, i.e. DGSR which contains
+ status for all the 4 DMA channels
+- ranges : describes the mapping between the address space of the
+ DMA channels and the address space of the DMA controller
- cell-index : controller index. 0 for controller @ 0x8100
-- interrupts : <interrupt mapping for DMA IRQ>
+- interrupts : interrupt specifier for DMA IRQ
- interrupt-parent : optional, if needed for interrupt mapping

-
- DMA channel nodes:
- - compatible : compatible list, contains 2 entries, first is
- "fsl,CHIP-dma-channel", where CHIP is the processor
- (mpc8349, mpc8350, etc.) and the second is
- "fsl,elo-dma-channel". However, see note below.
- - reg : <registers mapping for channel>
- - cell-index : dma channel index starts at 0.
+ - compatible : must include "fsl,elo-dma-channel"
+ However, see note below.
+ - reg : DMA channel specific registers
+ - cell-index : DMA channel index starts at 0.

Optional properties:
- - interrupts : <interrupt mapping for DMA channel IRQ>
- (on 83xx this is expected to be identical to
- the interrupts property of the parent node)
+ - interrupts : interrupt specifier for DMA channel IRQ
+ (on 83xx this is expected to be identical to
+ the interrupts property of the parent node)
- interrupt-parent : optional, if needed for interrupt mapping

Example:
@@ -70,30 +67,27 @@ Example:
};
};

-* Freescale 85xx/86xx DMA Controller
-
-Freescale PowerPC 85xx/86xx have on chip general purpose DMA controllers.
+** Freescale EloPlus DMA Controller
+ This is a 4-channel DMA controller with extended addresses and chaining,
+ mainly used in Freescale mpc85xx/86xx, Pxxx and BSC series chips, such as
+ mpc8540, mpc8641 p4080, bsc9131 etc.

Required properties:

-- compatible : compatible list, contains 2 entries, first is
- "fsl,CHIP-dma", where CHIP is the processor
- (mpc8540, mpc8540, etc.) and the second is
- "fsl,eloplus-dma"
-- reg : <registers mapping for DMA general status reg>
+- compatible : must include "fsl,eloplus-dma"
+- reg : DMA General Status Register, i.e. DGSR which contains
+ status for all the 4 DMA channels
- cell-index : controller index. 0 for controller @ 0x21000,
1 for controller @ 0xc000
-- ranges : Should be defined as specified in 1) to describe the
- DMA controller channels.
+- ranges : describes the mapping between the address space of the
+ DMA channels and the address space of the DMA controller

- DMA channel nodes:
- - compatible : compatible list, contains 2 entries, first is
- "fsl,CHIP-dma-channel", where CHIP is the processor
- (mpc8540, mpc8560, etc.) and the second is
- "fsl,eloplus-dma-channel". However, see note below.
- - cell-index : dma channel index starts at 0.
- - reg : <registers mapping for channel>
- - interrupts : <interrupt mapping for DMA channel IRQ>
+ - compatible : must include "fsl,eloplus-dma-channel"
+ However, see note below.
+ - cell-index : DMA channel index starts at 0.
+ - reg : DMA channel specific registers
+ - interrupts : interrupt specifier for DMA channel IRQ
- interrupt-parent : optional, if needed for interrupt mapping

Example:
--
1.7.9.5


2013-09-18 10:16:25

by Hongbo Zhang

[permalink] [raw]
Subject: [PATCH v10 3/3] DMA: Freescale: update driver to support 8-channel DMA engine

From: Hongbo Zhang <[email protected]>

This patch adds support to 8-channel DMA engine, thus the driver works for both
the new 8-channel and the legacy 4-channel DMA engines.

Signed-off-by: Hongbo Zhang <[email protected]>
---
drivers/dma/Kconfig | 9 +++++----
drivers/dma/fsldma.c | 9 ++++++---
drivers/dma/fsldma.h | 2 +-
3 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 6825957..3979c65 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -89,14 +89,15 @@ config AT_HDMAC
Support the Atmel AHB DMA controller.

config FSL_DMA
- tristate "Freescale Elo and Elo Plus DMA support"
+ tristate "Freescale Elo series DMA support"
depends on FSL_SOC
select DMA_ENGINE
select ASYNC_TX_ENABLE_CHANNEL_SWITCH
---help---
- Enable support for the Freescale Elo and Elo Plus DMA controllers.
- The Elo is the DMA controller on some 82xx and 83xx parts, and the
- Elo Plus is the DMA controller on 85xx and 86xx parts.
+ Enable support for the Freescale Elo series DMA controllers.
+ The Elo is the DMA controller on some mpc82xx and mpc83xx parts, the
+ EloPlus is on mpc85xx and mpc86xx and Pxxx parts, and the Elo3 is on
+ some Txxx and Bxxx parts.

config MPC512X_DMA
tristate "Freescale MPC512x built-in DMA engine support"
diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c
index 49e8fbd..16a9a48 100644
--- a/drivers/dma/fsldma.c
+++ b/drivers/dma/fsldma.c
@@ -1261,7 +1261,9 @@ static int fsl_dma_chan_probe(struct fsldma_device *fdev,
WARN_ON(fdev->feature != chan->feature);

chan->dev = fdev->dev;
- chan->id = ((res.start - 0x100) & 0xfff) >> 7;
+ chan->id = (res.start & 0xfff) < 0x300 ?
+ ((res.start - 0x100) & 0xfff) >> 7 :
+ ((res.start - 0x200) & 0xfff) >> 7;
if (chan->id >= FSL_DMA_MAX_CHANS_PER_DEVICE) {
dev_err(fdev->dev, "too many channels for device\n");
err = -EINVAL;
@@ -1434,6 +1436,7 @@ static int fsldma_of_remove(struct platform_device *op)
}

static const struct of_device_id fsldma_of_ids[] = {
+ { .compatible = "fsl,elo3-dma", },
{ .compatible = "fsl,eloplus-dma", },
{ .compatible = "fsl,elo-dma", },
{}
@@ -1455,7 +1458,7 @@ static struct platform_driver fsldma_of_driver = {

static __init int fsldma_init(void)
{
- pr_info("Freescale Elo / Elo Plus DMA driver\n");
+ pr_info("Freescale Elo series DMA driver\n");
return platform_driver_register(&fsldma_of_driver);
}

@@ -1467,5 +1470,5 @@ static void __exit fsldma_exit(void)
subsys_initcall(fsldma_init);
module_exit(fsldma_exit);

-MODULE_DESCRIPTION("Freescale Elo / Elo Plus DMA driver");
+MODULE_DESCRIPTION("Freescale Elo series DMA driver");
MODULE_LICENSE("GPL");
diff --git a/drivers/dma/fsldma.h b/drivers/dma/fsldma.h
index f5c3879..1ffc244 100644
--- a/drivers/dma/fsldma.h
+++ b/drivers/dma/fsldma.h
@@ -112,7 +112,7 @@ struct fsldma_chan_regs {
};

struct fsldma_chan;
-#define FSL_DMA_MAX_CHANS_PER_DEVICE 4
+#define FSL_DMA_MAX_CHANS_PER_DEVICE 8

struct fsldma_device {
void __iomem *regs; /* DGSR register base */
--
1.7.9.5


2013-09-18 10:16:23

by Hongbo Zhang

[permalink] [raw]
Subject: [PATCH v10 2/3] DMA: Freescale: Add new 8-channel DMA engine device tree nodes

From: Hongbo Zhang <[email protected]>

Freescale QorIQ T4 and B4 introduce new 8-channel DMA engines, this patch adds
the device tree nodes for them.

Signed-off-by: Hongbo Zhang <[email protected]>
---
.../devicetree/bindings/powerpc/fsl/dma.txt | 69 ++++++++++++++++
arch/powerpc/boot/dts/fsl/b4si-post.dtsi | 4 +-
arch/powerpc/boot/dts/fsl/elo3-dma-0.dtsi | 82 ++++++++++++++++++++
arch/powerpc/boot/dts/fsl/elo3-dma-1.dtsi | 82 ++++++++++++++++++++
arch/powerpc/boot/dts/fsl/t4240si-post.dtsi | 4 +-
5 files changed, 237 insertions(+), 4 deletions(-)
create mode 100644 arch/powerpc/boot/dts/fsl/elo3-dma-0.dtsi
create mode 100644 arch/powerpc/boot/dts/fsl/elo3-dma-1.dtsi

diff --git a/Documentation/devicetree/bindings/powerpc/fsl/dma.txt b/Documentation/devicetree/bindings/powerpc/fsl/dma.txt
index 0584168..414fe42 100644
--- a/Documentation/devicetree/bindings/powerpc/fsl/dma.txt
+++ b/Documentation/devicetree/bindings/powerpc/fsl/dma.txt
@@ -128,6 +128,75 @@ Example:
};
};

+** Freescale Elo3 DMA Controller
+ DMA controller which has same function as EloPlus except that Elo3 has 8
+ channels while EloPlus has only 4, it is used in Freescale Txxx and Bxxx
+ series chips, such as t1040, t4240, b4860.
+
+Required properties:
+
+- compatible : must include "fsl,elo3-dma"
+- reg : DMA General Status Registers, i.e. DGSR0 which contains
+ status for channel 1~4, and DGSR1 for channel 5~8
+- ranges : describes the mapping between the address space of the
+ DMA channels and the address space of the DMA controller
+
+- DMA channel nodes:
+ - compatible : must include "fsl,eloplus-dma-channel"
+ - reg : DMA channel specific registers
+ - interrupts : interrupt specifier for DMA channel IRQ
+ - interrupt-parent : optional, if needed for interrupt mapping
+
+Example:
+dma@100300 {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ compatible = "fsl,elo3-dma";
+ reg = <0x100300 0x4>,
+ <0x100600 0x4>;
+ ranges = <0x0 0x100100 0x500>;
+ dma-channel@0 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x0 0x80>;
+ interrupts = <28 2 0 0>;
+ };
+ dma-channel@80 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x80 0x80>;
+ interrupts = <29 2 0 0>;
+ };
+ dma-channel@100 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x100 0x80>;
+ interrupts = <30 2 0 0>;
+ };
+ dma-channel@180 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x180 0x80>;
+ interrupts = <31 2 0 0>;
+ };
+ dma-channel@300 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x300 0x80>;
+ interrupts = <76 2 0 0>;
+ };
+ dma-channel@380 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x380 0x80>;
+ interrupts = <77 2 0 0>;
+ };
+ dma-channel@400 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x400 0x80>;
+ interrupts = <78 2 0 0>;
+ };
+ dma-channel@480 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x480 0x80>;
+ interrupts = <79 2 0 0>;
+ };
+};
+
Note on DMA channel compatible properties: The compatible property must say
"fsl,elo-dma-channel" or "fsl,eloplus-dma-channel" to be used by the Elo DMA
driver (fsldma). Any DMA channel used by fsldma cannot be used by another
diff --git a/arch/powerpc/boot/dts/fsl/b4si-post.dtsi b/arch/powerpc/boot/dts/fsl/b4si-post.dtsi
index 7399154..ea53ea1 100644
--- a/arch/powerpc/boot/dts/fsl/b4si-post.dtsi
+++ b/arch/powerpc/boot/dts/fsl/b4si-post.dtsi
@@ -223,13 +223,13 @@
reg = <0xe2000 0x1000>;
};

-/include/ "qoriq-dma-0.dtsi"
+/include/ "elo3-dma-0.dtsi"
dma@100300 {
fsl,iommu-parent = <&pamu0>;
fsl,liodn-reg = <&guts 0x580>; /* DMA1LIODNR */
};

-/include/ "qoriq-dma-1.dtsi"
+/include/ "elo3-dma-1.dtsi"
dma@101300 {
fsl,iommu-parent = <&pamu0>;
fsl,liodn-reg = <&guts 0x584>; /* DMA2LIODNR */
diff --git a/arch/powerpc/boot/dts/fsl/elo3-dma-0.dtsi b/arch/powerpc/boot/dts/fsl/elo3-dma-0.dtsi
new file mode 100644
index 0000000..3c210e0
--- /dev/null
+++ b/arch/powerpc/boot/dts/fsl/elo3-dma-0.dtsi
@@ -0,0 +1,82 @@
+/*
+ * QorIQ Elo3 DMA device tree stub [ controller @ offset 0x100000 ]
+ *
+ * Copyright 2013 Freescale Semiconductor Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * * Neither the name of Freescale Semiconductor nor the
+ * names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ *
+ * ALTERNATIVELY, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") as published by the Free Software
+ * Foundation, either version 2 of that License or (at your option) any
+ * later version.
+ *
+ * THIS SOFTWARE IS PROVIDED BY Freescale Semiconductor ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL Freescale Semiconductor BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+dma0: dma@100300 {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ compatible = "fsl,elo3-dma";
+ reg = <0x100300 0x4>,
+ <0x100600 0x4>;
+ ranges = <0x0 0x100100 0x500>;
+ dma-channel@0 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x0 0x80>;
+ interrupts = <28 2 0 0>;
+ };
+ dma-channel@80 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x80 0x80>;
+ interrupts = <29 2 0 0>;
+ };
+ dma-channel@100 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x100 0x80>;
+ interrupts = <30 2 0 0>;
+ };
+ dma-channel@180 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x180 0x80>;
+ interrupts = <31 2 0 0>;
+ };
+ dma-channel@300 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x300 0x80>;
+ interrupts = <76 2 0 0>;
+ };
+ dma-channel@380 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x380 0x80>;
+ interrupts = <77 2 0 0>;
+ };
+ dma-channel@400 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x400 0x80>;
+ interrupts = <78 2 0 0>;
+ };
+ dma-channel@480 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x480 0x80>;
+ interrupts = <79 2 0 0>;
+ };
+};
diff --git a/arch/powerpc/boot/dts/fsl/elo3-dma-1.dtsi b/arch/powerpc/boot/dts/fsl/elo3-dma-1.dtsi
new file mode 100644
index 0000000..cccf3bb
--- /dev/null
+++ b/arch/powerpc/boot/dts/fsl/elo3-dma-1.dtsi
@@ -0,0 +1,82 @@
+/*
+ * QorIQ Elo3 DMA device tree stub [ controller @ offset 0x101000 ]
+ *
+ * Copyright 2013 Freescale Semiconductor Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * * Neither the name of Freescale Semiconductor nor the
+ * names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ *
+ * ALTERNATIVELY, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") as published by the Free Software
+ * Foundation, either version 2 of that License or (at your option) any
+ * later version.
+ *
+ * THIS SOFTWARE IS PROVIDED BY Freescale Semiconductor ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL Freescale Semiconductor BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+dma1: dma@101300 {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ compatible = "fsl,elo3-dma";
+ reg = <0x101300 0x4>,
+ <0x101600 0x4>;
+ ranges = <0x0 0x101100 0x500>;
+ dma-channel@0 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x0 0x80>;
+ interrupts = <32 2 0 0>;
+ };
+ dma-channel@80 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x80 0x80>;
+ interrupts = <33 2 0 0>;
+ };
+ dma-channel@100 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x100 0x80>;
+ interrupts = <34 2 0 0>;
+ };
+ dma-channel@180 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x180 0x80>;
+ interrupts = <35 2 0 0>;
+ };
+ dma-channel@300 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x300 0x80>;
+ interrupts = <80 2 0 0>;
+ };
+ dma-channel@380 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x380 0x80>;
+ interrupts = <81 2 0 0>;
+ };
+ dma-channel@400 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x400 0x80>;
+ interrupts = <82 2 0 0>;
+ };
+ dma-channel@480 {
+ compatible = "fsl,eloplus-dma-channel";
+ reg = <0x480 0x80>;
+ interrupts = <83 2 0 0>;
+ };
+};
diff --git a/arch/powerpc/boot/dts/fsl/t4240si-post.dtsi b/arch/powerpc/boot/dts/fsl/t4240si-post.dtsi
index bd611a9..ec95c60 100644
--- a/arch/powerpc/boot/dts/fsl/t4240si-post.dtsi
+++ b/arch/powerpc/boot/dts/fsl/t4240si-post.dtsi
@@ -387,8 +387,8 @@
reg = <0xea000 0x4000>;
};

-/include/ "qoriq-dma-0.dtsi"
-/include/ "qoriq-dma-1.dtsi"
+/include/ "elo3-dma-0.dtsi"
+/include/ "elo3-dma-1.dtsi"

/include/ "qoriq-espi-0.dtsi"
spi@110000 {
--
1.7.9.5


2013-09-23 17:04:44

by Stephen Warren

[permalink] [raw]
Subject: Re: [PATCH v10 2/3] DMA: Freescale: Add new 8-channel DMA engine device tree nodes

On 09/18/2013 04:15 AM, [email protected] wrote:
> From: Hongbo Zhang <[email protected]>
>
> Freescale QorIQ T4 and B4 introduce new 8-channel DMA engines, this patch adds
> the device tree nodes for them.

> diff --git a/Documentation/devicetree/bindings/powerpc/fsl/dma.txt b/Documentation/devicetree/bindings/powerpc/fsl/dma.txt

> +Required properties:
> +
> +- compatible : must include "fsl,elo3-dma"
> +- reg : DMA General Status Registers, i.e. DGSR0 which contains
> + status for channel 1~4, and DGSR1 for channel 5~8

Is that a single entry, which is large enough to cover both registers,
or a pair of entries, one per register? Reading the text, I might assume
the former, but looking at the examples, it's the latter.

...
+Example:
> +dma@100300 {
> + #address-cells = <1>;
> + #size-cells = <1>;
> + compatible = "fsl,elo3-dma";
> + reg = <0x100300 0x4>,
> + <0x100600 0x4>;

2013-09-24 10:31:10

by Hongbo Zhang

[permalink] [raw]
Subject: Re: [PATCH v10 2/3] DMA: Freescale: Add new 8-channel DMA engine device tree nodes

On 09/24/2013 01:04 AM, Stephen Warren wrote:
> On 09/18/2013 04:15 AM, [email protected] wrote:
>> From: Hongbo Zhang <[email protected]>
>>
>> Freescale QorIQ T4 and B4 introduce new 8-channel DMA engines, this patch adds
>> the device tree nodes for them.
>> diff --git a/Documentation/devicetree/bindings/powerpc/fsl/dma.txt b/Documentation/devicetree/bindings/powerpc/fsl/dma.txt
>> +Required properties:
>> +
>> +- compatible : must include "fsl,elo3-dma"
>> +- reg : DMA General Status Registers, i.e. DGSR0 which contains
>> + status for channel 1~4, and DGSR1 for channel 5~8
> Is that a single entry, which is large enough to cover both registers,
> or a pair of entries, one per register? Reading the text, I might assume
> the former, but looking at the examples, it's the latter.
My impression is that I cannot tell it is one larger entry or two
entries by reading the description text, but the example gives the answer.
Is it so important to specify it is only one entry or entries list?
I prefer language as concise as possible, especially for the common
properties such as reg and interrupt (eg the reg is implicitly offset
and length of registers, can be continuous or not), it is difficult or
unnecessary or impossible to describe much details, the example can also
work as a complementary description, otherwise no need to put an example
in the binding document.

> ...
> +Example:
>> +dma@100300 {
>> + #address-cells = <1>;
>> + #size-cells = <1>;
>> + compatible = "fsl,elo3-dma";
>> + reg = <0x100300 0x4>,
>> + <0x100600 0x4>;
>


2013-09-24 17:31:17

by Stephen Warren

[permalink] [raw]
Subject: Re: [PATCH v10 2/3] DMA: Freescale: Add new 8-channel DMA engine device tree nodes

On 09/24/2013 04:30 AM, Hongbo Zhang wrote:
> On 09/24/2013 01:04 AM, Stephen Warren wrote:
>> On 09/18/2013 04:15 AM, [email protected] wrote:
>>> From: Hongbo Zhang <[email protected]>
>>>
>>> Freescale QorIQ T4 and B4 introduce new 8-channel DMA engines, this
>>> patch adds
>>> the device tree nodes for them.
>>> diff --git a/Documentation/devicetree/bindings/powerpc/fsl/dma.txt
>>> b/Documentation/devicetree/bindings/powerpc/fsl/dma.txt
>>> +Required properties:
>>> +
>>> +- compatible : must include "fsl,elo3-dma"
>>> +- reg : DMA General Status Registers, i.e. DGSR0 which
>>> contains
>>> + status for channel 1~4, and DGSR1 for channel 5~8
>> Is that a single entry, which is large enough to cover both registers,
>> or a pair of entries, one per register? Reading the text, I might assume
>> the former, but looking at the examples, it's the latter.
> My impression is that I cannot tell it is one larger entry or two
> entries by reading the description text, but the example gives the answer.
> Is it so important to specify it is only one entry or entries list?
> I prefer language as concise as possible, especially for the common
> properties such as reg and interrupt (eg the reg is implicitly offset
> and length of registers, can be continuous or not), it is difficult or
> unnecessary or impossible to describe much details, the example can also
> work as a complementary description, otherwise no need to put an example
> in the binding document.

The description of the properties should fully describe them. The
example is just an example, not a specification of the properties.

2013-09-25 07:37:01

by Hongbo Zhang

[permalink] [raw]
Subject: Re: [PATCH v10 2/3] DMA: Freescale: Add new 8-channel DMA engine device tree nodes

On 09/25/2013 01:31 AM, Stephen Warren wrote:
> On 09/24/2013 04:30 AM, Hongbo Zhang wrote:
>> On 09/24/2013 01:04 AM, Stephen Warren wrote:
>>> On 09/18/2013 04:15 AM, [email protected] wrote:
>>>> From: Hongbo Zhang <[email protected]>
>>>>
>>>> Freescale QorIQ T4 and B4 introduce new 8-channel DMA engines, this
>>>> patch adds
>>>> the device tree nodes for them.
>>>> diff --git a/Documentation/devicetree/bindings/powerpc/fsl/dma.txt
>>>> b/Documentation/devicetree/bindings/powerpc/fsl/dma.txt
>>>> +Required properties:
>>>> +
>>>> +- compatible : must include "fsl,elo3-dma"
>>>> +- reg : DMA General Status Registers, i.e. DGSR0 which
>>>> contains
>>>> + status for channel 1~4, and DGSR1 for channel 5~8
>>> Is that a single entry, which is large enough to cover both registers,
>>> or a pair of entries, one per register? Reading the text, I might assume
>>> the former, but looking at the examples, it's the latter.
>> My impression is that I cannot tell it is one larger entry or two
>> entries by reading the description text, but the example gives the answer.
>> Is it so important to specify it is only one entry or entries list?
>> I prefer language as concise as possible, especially for the common
>> properties such as reg and interrupt (eg the reg is implicitly offset
>> and length of registers, can be continuous or not), it is difficult or
>> unnecessary or impossible to describe much details, the example can also
>> work as a complementary description, otherwise no need to put an example
>> in the binding document.
> The description of the properties should fully describe them. The
> example is just an example, not a specification of the properties.
>
It is OK for me to update the description like this:
reg: containing two entries for DMA General Status Registers, i.e.
DGSR0 which contains + status for channel 1~4, and DGSR1 for channel 5~8

and let me wait one or more days to see if other reviewers/maintainers
have further comments before I send our another iteration.

By the way, I know maybe it is difficult, but why not introduce a
document of maintaining rules for the dt binding docs? we have dedicated
maintainers for this part now. Description language from one submitter
cannot satisfy every reviewer/maintainer, for a reg property, is it
necessary to say "offset and length", to say "how many entries", to say
"register functions and even names"? If there is specific rules (even
with good examples), it will be convenient for both submitter and
reviewers. Without rules/guidelines, new submitter would like to follow
old bad samples.


2013-09-26 01:47:40

by Scott Wood

[permalink] [raw]
Subject: Re: [PATCH v10 2/3] DMA: Freescale: Add new 8-channel DMA engine device tree nodes

On Wed, 2013-09-25 at 15:35 +0800, Hongbo Zhang wrote:
> By the way, I know maybe it is difficult, but why not introduce a
> document of maintaining rules for the dt binding docs? we have dedicated
> maintainers for this part now. Description language from one submitter
> cannot satisfy every reviewer/maintainer, for a reg property, is it
> necessary to say "offset and length",

Don't say "offset and length". It's both redundant with the base
definition of the reg property, and overly specific because it makes
assumptions about how the parent node's ranges are set up (sometimes we
want to be that specific, but usually not).

> to say "how many entries", to say "register functions and even names"?

If there's more than one
entry/resource/whatever-we-decide-to-call-it-but-let's-pick-something-canonical, then say how many there are and what each one means.

-Scott


2013-09-26 03:07:55

by David Gibson

[permalink] [raw]
Subject: Re: [PATCH v10 2/3] DMA: Freescale: Add new 8-channel DMA engine device tree nodes

On Wed, Sep 25, 2013 at 08:46:32PM -0500, Scott Wood wrote:
> On Wed, 2013-09-25 at 15:35 +0800, Hongbo Zhang wrote:
> > By the way, I know maybe it is difficult, but why not introduce a
> > document of maintaining rules for the dt binding docs? we have dedicated
> > maintainers for this part now. Description language from one submitter
> > cannot satisfy every reviewer/maintainer, for a reg property, is it
> > necessary to say "offset and length",
>
> Don't say "offset and length". It's both redundant with the base
> definition of the reg property, and overly specific because it makes
> assumptions about how the parent node's ranges are set up (sometimes we
> want to be that specific, but usually not).

To look at it another way, the format of the 'reg' property is defined
by the parent bus's binding, not the binding of the node itself.

--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson


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2013-09-26 05:06:29

by Hongbo Zhang

[permalink] [raw]
Subject: Re: [PATCH v10 2/3] DMA: Freescale: Add new 8-channel DMA engine device tree nodes

On 09/26/2013 10:28 AM, David Gibson wrote:
> On Wed, Sep 25, 2013 at 08:46:32PM -0500, Scott Wood wrote:
>> On Wed, 2013-09-25 at 15:35 +0800, Hongbo Zhang wrote:
>>> By the way, I know maybe it is difficult, but why not introduce a
>>> document of maintaining rules for the dt binding docs? we have dedicated
>>> maintainers for this part now. Description language from one submitter
>>> cannot satisfy every reviewer/maintainer, for a reg property, is it
>>> necessary to say "offset and length",
>> Don't say "offset and length". It's both redundant with the base
>> definition of the reg property, and overly specific because it makes
>> assumptions about how the parent node's ranges are set up (sometimes we
>> want to be that specific, but usually not).

Thanks for your answer Scott.
In fact my questions are mainly sample questions to file the necessary
rules of dt binding.
> To look at it another way, the format of the 'reg' property is defined
> by the parent bus's binding, not the binding of the node itself.
>
Whatever the rule is, if it is reasonable and accepted, just as I said,
we need to file it.