[PATCH v2 0/5] Add STM32 DMAMUX support

[PATCH v2 0/5] Add STM32 DMAMUX support

[Pierre-Yves MORDRET]

This patchset adds support for the STM32 DMA multiplexer.
It allows to map any peripheral DMA request to any channel of the product
DMAs.
This IP has been introduced with STM32H7 SoC.

Pierre-Yves MORDRET (5):
  dt-bindings: Document the STM32 DMAMUX bindings
  dmaengine: Add STM32 DMAMUX driver
  dt-bindings: stm32-dma: Add property to handle STM32 DMAMUX
  dmaengine: stm32-dma: Add support for STM32 DMAMUX
  ARM: configs: stm32: Add DMAMUX support in STM32 defconfig

 .../devicetree/bindings/dma/stm32-dma.txt          |   5 +-
 .../devicetree/bindings/dma/stm32-dmamux.txt       |  57 +++++
 arch/arm/configs/stm32_defconfig                   |   1 +
 drivers/dma/Kconfig                                |   9 +
 drivers/dma/Makefile                               |   1 +
 drivers/dma/stm32-dma.c                            |  44 ++--
 drivers/dma/stm32-dmamux.c                         | 253 +++++++++++++++++++++
 include/linux/dma/stm32-dmamux.h                   |  21 ++
 8 files changed, 377 insertions(+), 14 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/dma/stm32-dmamux.txt
 create mode 100644 drivers/dma/stm32-dmamux.c
 create mode 100644 include/linux/dma/stm32-dmamux.h

-- 
1.9.1

[PATCH v2 1/5] dt-bindings: Document the STM32 DMAMUX bindings

[Pierre-Yves MORDRET]

This patch adds the documentation of device tree bindings for the STM32
DMAMUX.

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
---
 Version history:
    v2:
        * Move clock bindings from optional to mandatory one
        * Drop channelID bindings as managed dynamically from now on by
          DMAMUX driver.
---
---
 .../devicetree/bindings/dma/stm32-dmamux.txt       | 57 ++++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/dma/stm32-dmamux.txt

diff --git a/Documentation/devicetree/bindings/dma/stm32-dmamux.txt b/Documentation/devicetree/bindings/dma/stm32-dmamux.txt
new file mode 100644
index 0000000..1d413c5
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/stm32-dmamux.txt
@@ -0,0 +1,57 @@
+STM32 DMA MUX (DMA request router)
+
+Required properties:
+- compatible:	"st,stm32-dmamux"
+- reg:		Memory map for accessing module
+- #dma-cells:	Should be set to <3>.
+		For more details about the three cells, please see
+		stm32-dma.txt documentation binding file
+- dma-masters:	Phandle pointing to the DMA controller
+
+Optional properties:
+- dma-channels : Number of DMA channels supported.
+- dma-requests : Number of DMA requests supported.
+- resets: Reference to a reset controller asserting the DMA controller
+- clocks: Input clock of the DMAMUX instance.
+
+Example:
+
+/* DMA controller */
+dma2: dma-controller@40026400 {
+	compatible = "st,stm32-dma";
+	reg = <0x40026400 0x400>;
+	interrupts = <56>,
+		     <57>,
+		     <58>,
+		     <59>,
+		     <60>,
+		     <68>,
+		     <69>,
+		     <70>;
+	clocks = <&clk_hclk>;
+	#dma-cells = <4>;
+	st,mem2mem;
+	resets = <&rcc 150>;
+	st,dmamux;
+	dma-channels = <8>;
+};
+
+/* DMA mux */
+dmamux2: dma-router@40020820 {
+	compatible = "st,stm32-dmamux";
+	reg = <0x40020800 0x1c>;
+	#dma-cells = <3>;
+	dma-requests = <128>;
+	dma-masters = <&dma2>;
+};
+
+/* DMA client */
+usart1: serial@40011000 {
+	compatible = "st,stm32-usart", "st,stm32-uart";
+	reg = <0x40011000 0x400>;
+	interrupts = <37>;
+	clocks = <&clk_pclk2>;
+	dmas = <&dmamux2 41 0x414 0>,
+	       <&dmamux2 42 0x414 0>;
+	dma-names = "rx", "tx";
+};
-- 
1.9.1

Re: [PATCH v2 1/5] dt-bindings: Document the STM32 DMAMUX bindings

[Rob Herring]

On Fri, Jun 23, 2017 at 03:00:49PM +0200, Pierre-Yves MORDRET wrote:
> This patch adds the documentation of device tree bindings for the STM32
> DMAMUX.
> 
> Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
> Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
> ---
>  Version history:
>     v2:
>         * Move clock bindings from optional to mandatory one
>         * Drop channelID bindings as managed dynamically from now on by
>           DMAMUX driver.
> ---
> ---
>  .../devicetree/bindings/dma/stm32-dmamux.txt       | 57 ++++++++++++++++++++++
>  1 file changed, 57 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/dma/stm32-dmamux.txt
> 
> diff --git a/Documentation/devicetree/bindings/dma/stm32-dmamux.txt b/Documentation/devicetree/bindings/dma/stm32-dmamux.txt
> new file mode 100644
> index 0000000..1d413c5
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/dma/stm32-dmamux.txt
> @@ -0,0 +1,57 @@
> +STM32 DMA MUX (DMA request router)
> +
> +Required properties:
> +- compatible:	"st,stm32-dmamux"

This should be SoC specific (or at least have f4, h7, etc.).

> +- reg:		Memory map for accessing module
> +- #dma-cells:	Should be set to <3>.
> +		For more details about the three cells, please see
> +		stm32-dma.txt documentation binding file

The example below has 4 cells for the dma ctrlr?

> +- dma-masters:	Phandle pointing to the DMA controller
> +
> +Optional properties:
> +- dma-channels : Number of DMA channels supported.
> +- dma-requests : Number of DMA requests supported.
> +- resets: Reference to a reset controller asserting the DMA controller
> +- clocks: Input clock of the DMAMUX instance.
> +
> +Example:
> +
> +/* DMA controller */
> +dma2: dma-controller@40026400 {
> +	compatible = "st,stm32-dma";
> +	reg = <0x40026400 0x400>;
> +	interrupts = <56>,
> +		     <57>,
> +		     <58>,
> +		     <59>,
> +		     <60>,
> +		     <68>,
> +		     <69>,
> +		     <70>;
> +	clocks = <&clk_hclk>;
> +	#dma-cells = <4>;
> +	st,mem2mem;
> +	resets = <&rcc 150>;
> +	st,dmamux;
> +	dma-channels = <8>;
> +};
> +
> +/* DMA mux */
> +dmamux2: dma-router@40020820 {
> +	compatible = "st,stm32-dmamux";
> +	reg = <0x40020800 0x1c>;
> +	#dma-cells = <3>;
> +	dma-requests = <128>;
> +	dma-masters = <&dma2>;
> +};
> +
> +/* DMA client */
> +usart1: serial@40011000 {
> +	compatible = "st,stm32-usart", "st,stm32-uart";
> +	reg = <0x40011000 0x400>;
> +	interrupts = <37>;
> +	clocks = <&clk_pclk2>;
> +	dmas = <&dmamux2 41 0x414 0>,
> +	       <&dmamux2 42 0x414 0>;
> +	dma-names = "rx", "tx";
> +};
> -- 
> 1.9.1
> 

Re: [PATCH v2 1/5] dt-bindings: Document the STM32 DMAMUX bindings

[Pierre Yves MORDRET]

On 06/26/2017 09:28 PM, Rob Herring wrote:
> On Fri, Jun 23, 2017 at 03:00:49PM +0200, Pierre-Yves MORDRET wrote:
>> This patch adds the documentation of device tree bindings for the STM32
>> DMAMUX.
>>
>> Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
>> Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
>> ---
>>   Version history:
>>      v2:
>>          * Move clock bindings from optional to mandatory one
>>          * Drop channelID bindings as managed dynamically from now on by
>>            DMAMUX driver.
>> ---
>> ---
>>   .../devicetree/bindings/dma/stm32-dmamux.txt       | 57 ++++++++++++++++++++++
>>   1 file changed, 57 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/dma/stm32-dmamux.txt
>>
>> diff --git a/Documentation/devicetree/bindings/dma/stm32-dmamux.txt b/Documentation/devicetree/bindings/dma/stm32-dmamux.txt
>> new file mode 100644
>> index 0000000..1d413c5
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/dma/stm32-dmamux.txt
>> @@ -0,0 +1,57 @@
>> +STM32 DMA MUX (DMA request router)
>> +
>> +Required properties:
>> +- compatible:	"st,stm32-dmamux"
> 
> This should be SoC specific (or at least have f4, h7, etc.).

Ok.
compatible:    "st,stm32h7-dmamux"

> 
>> +- reg:		Memory map for accessing module
>> +- #dma-cells:	Should be set to <3>.
>> +		For more details about the three cells, please see
>> +		stm32-dma.txt documentation binding file
> 
> The example below has 4 cells for the dma ctrlr?
> 

Yes.
DMA Controller has 4 cells and DMAMUX only 3.
But I agree this is not very clear. I should add a comment on each cells 
to highlight the mapping onto DMA Cells

>> +- dma-masters:	Phandle pointing to the DMA controller
>> +
>> +Optional properties:
>> +- dma-channels : Number of DMA channels supported.
>> +- dma-requests : Number of DMA requests supported.
>> +- resets: Reference to a reset controller asserting the DMA controller
>> +- clocks: Input clock of the DMAMUX instance.
>> +
>> +Example:
>> +
>> +/* DMA controller */
>> +dma2: dma-controller@40026400 {
>> +	compatible = "st,stm32-dma";
>> +	reg = <0x40026400 0x400>;
>> +	interrupts = <56>,
>> +		     <57>,
>> +		     <58>,
>> +		     <59>,
>> +		     <60>,
>> +		     <68>,
>> +		     <69>,
>> +		     <70>;
>> +	clocks = <&clk_hclk>;
>> +	#dma-cells = <4>;
>> +	st,mem2mem;
>> +	resets = <&rcc 150>;
>> +	st,dmamux;
>> +	dma-channels = <8>;
>> +};
>> +
>> +/* DMA mux */
>> +dmamux2: dma-router@40020820 {
>> +	compatible = "st,stm32-dmamux";
>> +	reg = <0x40020800 0x1c>;
>> +	#dma-cells = <3>;
>> +	dma-requests = <128>;
>> +	dma-masters = <&dma2>;
>> +};
>> +
>> +/* DMA client */
>> +usart1: serial@40011000 {
>> +	compatible = "st,stm32-usart", "st,stm32-uart";
>> +	reg = <0x40011000 0x400>;
>> +	interrupts = <37>;
>> +	clocks = <&clk_pclk2>;
>> +	dmas = <&dmamux2 41 0x414 0>,
>> +	       <&dmamux2 42 0x414 0>;
>> +	dma-names = "rx", "tx";
>> +};
>> -- 
>> 1.9.1
>>

Py

[PATCH v2 2/5] dmaengine: Add STM32 DMAMUX driver

[Pierre-Yves MORDRET]

This patch implements the STM32 DMAMUX driver.

The DMAMUX request multiplexer allows routing a DMA request line between
the peripherals and the DMA controllers of the product. The routing
function is ensured by a programmable multi-channel DMA request line
multiplexer. Each channel selects a unique DMA request line,
unconditionally or synchronously with events from its DMAMUX
synchronization inputs. The DMAMUX may also be used as a DMA request
generator from programmable events on its input trigger signals

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
---
 Version history:
    v2:
        * Dynamic channelID allocation.
        * Change of_property_... by device_property.
        * New clock management.
        * DMAMUX Configuration API.
---
---
 drivers/dma/Kconfig              |   9 ++
 drivers/dma/Makefile             |   1 +
 drivers/dma/stm32-dmamux.c       | 253 +++++++++++++++++++++++++++++++++++++++
 include/linux/dma/stm32-dmamux.h |  21 ++++
 4 files changed, 284 insertions(+)
 create mode 100644 drivers/dma/stm32-dmamux.c
 create mode 100644 include/linux/dma/stm32-dmamux.h

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index fa8f9c0..34d9088 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -477,6 +477,15 @@ config STM32_DMA
 	  If you have a board based on such a MCU and wish to use DMA say Y
 	  here.
 
+config STM32_DMAMUX
+	bool "STMicroelectronics STM32 dma multiplexer support"
+	depends on STM32_DMA || COMPILE_TEST
+	help
+	  Enable support for the on-chip DMA multiplexer on STMicroelectronics
+	  STM32 MCUs.
+	  If you have a board based on such a MCU and wish to use DMAMUX say Y
+	  here.
+
 config S3C24XX_DMAC
 	bool "Samsung S3C24XX DMA support"
 	depends on ARCH_S3C24XX || COMPILE_TEST
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index d12ab29..96bd47e 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -58,6 +58,7 @@ obj-$(CONFIG_RENESAS_DMA) += sh/
 obj-$(CONFIG_SIRF_DMA) += sirf-dma.o
 obj-$(CONFIG_STE_DMA40) += ste_dma40.o ste_dma40_ll.o
 obj-$(CONFIG_STM32_DMA) += stm32-dma.o
+obj-$(CONFIG_STM32_DMAMUX) += stm32-dmamux.o
 obj-$(CONFIG_S3C24XX_DMAC) += s3c24xx-dma.o
 obj-$(CONFIG_TXX9_DMAC) += txx9dmac.o
 obj-$(CONFIG_TEGRA20_APB_DMA) += tegra20-apb-dma.o
diff --git a/drivers/dma/stm32-dmamux.c b/drivers/dma/stm32-dmamux.c
new file mode 100644
index 0000000..ba39178
--- /dev/null
+++ b/drivers/dma/stm32-dmamux.c
@@ -0,0 +1,253 @@
+/*
+ * DMA Router driver for STM32 DMA MUX
+ *
+ * Copyright (C) 2017 M'Boumba Cedric Madianga <cedric.madianga@gmail.com>
+ *
+ * Based on TI DMA Crossbar driver
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/of_device.h>
+#include <linux/of_dma.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/dma/stm32-dmamux.h>
+
+#define STM32_DMAMUX_CCR(x)		(0x4 * (x))
+#define STM32_DMAMUX_MAX_CHANNELS	32
+#define STM32_DMAMUX_MAX_REQUESTS	255
+
+struct stm32_dmamux {
+	u32 request;
+	u32 chan_id;
+	bool busy;
+};
+
+struct stm32_dmamux_data {
+	struct dma_router dmarouter;
+	struct clk *clk;
+	struct reset_control *rst;
+	void __iomem *iomem;
+	u32 dmamux_requests; /* number of DMA requests connected to DMAMUX */
+	u32 dmamux_channels; /* Number of DMA channels supported */
+	spinlock_t lock; /* Protects register access */
+};
+
+static inline u32 stm32_dmamux_read(void __iomem *iomem, u32 reg)
+{
+	return readl_relaxed(iomem + reg);
+}
+
+static inline void stm32_dmamux_write(void __iomem *iomem, u32 reg, u32 val)
+{
+	writel_relaxed(val, iomem + reg);
+}
+
+int stm32_dmamux_set_config(struct device *dev, void *route_data, u32 chan_id)
+{
+	struct stm32_dmamux_data *dmamux = dev_get_drvdata(dev);
+	struct stm32_dmamux *mux = route_data;
+	u32 request = mux->request;
+	unsigned long flags;
+	int ret;
+
+	if (chan_id >= dmamux->dmamux_channels) {
+		dev_err(dev, "invalid channel id\n");
+		return -EINVAL;
+	}
+
+	/* Set dma request */
+	spin_lock_irqsave(&dmamux->lock, flags);
+	if (!IS_ERR(dmamux->clk)) {
+		ret = clk_enable(dmamux->clk);
+		if (ret < 0) {
+			spin_unlock_irqrestore(&dmamux->lock, flags);
+			dev_err(dev, "clk_prep_enable issue: %d\n", ret);
+			return ret;
+		}
+	}
+
+	stm32_dmamux_write(dmamux->iomem, STM32_DMAMUX_CCR(chan_id), request);
+
+	mux->chan_id = chan_id;
+	mux->busy = true;
+	spin_unlock_irqrestore(&dmamux->lock, flags);
+
+	dev_dbg(dev, "Mapping dma-router%dchan%d to request%d\n", dev->id,
+		mux->chan_id, mux->request);
+
+	return 0;
+}
+
+static void stm32_dmamux_free(struct device *dev, void *route_data)
+{
+	struct stm32_dmamux_data *dmamux = dev_get_drvdata(dev);
+	struct stm32_dmamux *mux = route_data;
+	unsigned long flags;
+
+	/* Clear dma request */
+	spin_lock_irqsave(&dmamux->lock, flags);
+	if (!mux->busy) {
+		spin_unlock_irqrestore(&dmamux->lock, flags);
+		goto end;
+	}
+
+	stm32_dmamux_write(dmamux->iomem, STM32_DMAMUX_CCR(mux->chan_id), 0);
+	if (!IS_ERR(dmamux->clk))
+		clk_disable(dmamux->clk);
+	spin_unlock_irqrestore(&dmamux->lock, flags);
+
+	dev_dbg(dev, "Unmapping dma-router%dchan%d (was routed to request%d)\n",
+		dev->id, mux->chan_id, mux->request);
+
+end:
+	kfree(mux);
+}
+
+static void *stm32_dmamux_route_allocate(struct of_phandle_args *dma_spec,
+					 struct of_dma *ofdma)
+{
+	struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
+	struct stm32_dmamux_data *dmamux = platform_get_drvdata(pdev);
+	struct stm32_dmamux *mux;
+
+	if (dma_spec->args_count != 3) {
+		dev_err(&pdev->dev, "invalid number of dma mux args\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (dma_spec->args[0] > dmamux->dmamux_requests) {
+		dev_err(&pdev->dev, "invalid mux request number: %d\n",
+			dma_spec->args[0]);
+		return ERR_PTR(-EINVAL);
+	}
+
+	/* The of_node_put() will be done in of_dma_router_xlate function */
+	dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
+	if (!dma_spec->np) {
+		dev_err(&pdev->dev, "can't get dma master\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	mux = kzalloc(sizeof(*mux), GFP_KERNEL);
+	if (!mux) {
+		of_node_put(dma_spec->np);
+		return ERR_PTR(-ENOMEM);
+	}
+	mux->request = dma_spec->args[0];
+
+	dma_spec->args[3] = dma_spec->args[2];
+	dma_spec->args[2] = dma_spec->args[1];
+	dma_spec->args[1] = 0;
+	dma_spec->args[0] = 0;
+	dma_spec->args_count = 4;
+
+	return mux;
+}
+
+static int stm32_dmamux_probe(struct platform_device *pdev)
+{
+	struct device_node *node = pdev->dev.of_node;
+	struct device_node *dma_node;
+	struct stm32_dmamux_data *stm32_dmamux;
+	struct resource *res;
+	void __iomem *iomem;
+	int i, ret;
+
+	if (!node)
+		return -ENODEV;
+
+	stm32_dmamux = devm_kzalloc(&pdev->dev, sizeof(*stm32_dmamux),
+				    GFP_KERNEL);
+	if (!stm32_dmamux)
+		return -ENOMEM;
+
+	dma_node = of_parse_phandle(node, "dma-masters", 0);
+	if (!dma_node) {
+		dev_err(&pdev->dev, "Can't get DMA master node\n");
+		return -ENODEV;
+	}
+
+	if (device_property_read_u32(&pdev->dev, "dma-channels",
+				     &stm32_dmamux->dmamux_channels))
+		stm32_dmamux->dmamux_channels = STM32_DMAMUX_MAX_CHANNELS;
+
+	if (device_property_read_u32(&pdev->dev, "dma-requests",
+				     &stm32_dmamux->dmamux_requests))
+		stm32_dmamux->dmamux_requests = STM32_DMAMUX_MAX_REQUESTS;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENODEV;
+
+	iomem = devm_ioremap_resource(&pdev->dev, res);
+	if (!iomem)
+		return -ENOMEM;
+
+	spin_lock_init(&stm32_dmamux->lock);
+
+	stm32_dmamux->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(stm32_dmamux->clk)) {
+		dev_info(&pdev->dev, "Missing controller clock\n");
+		return PTR_ERR(stm32_dmamux->clk);
+	}
+
+	stm32_dmamux->rst = devm_reset_control_get(&pdev->dev, NULL);
+	if (!IS_ERR(stm32_dmamux->rst)) {
+		reset_control_assert(stm32_dmamux->rst);
+		udelay(2);
+		reset_control_deassert(stm32_dmamux->rst);
+	}
+
+	stm32_dmamux->iomem = iomem;
+	stm32_dmamux->dmarouter.dev = &pdev->dev;
+	stm32_dmamux->dmarouter.route_free = stm32_dmamux_free;
+
+	platform_set_drvdata(pdev, stm32_dmamux);
+
+	if (!IS_ERR(stm32_dmamux->clk)) {
+		ret = clk_prepare_enable(stm32_dmamux->clk);
+		if (ret < 0) {
+			dev_err(&pdev->dev, "clk_prep_enable issue: %d\n", ret);
+			return ret;
+		}
+	}
+
+	/* Reset the dmamux */
+	for (i = 0; i < stm32_dmamux->dmamux_channels; i++)
+		stm32_dmamux_write(stm32_dmamux->iomem, STM32_DMAMUX_CCR(i), 0);
+
+	if (!IS_ERR(stm32_dmamux->clk))
+		clk_disable(stm32_dmamux->clk);
+
+	return of_dma_router_register(node, stm32_dmamux_route_allocate,
+				     &stm32_dmamux->dmarouter);
+}
+
+static const struct of_device_id stm32_dmamux_match[] = {
+	{ .compatible = "st,stm32-dmamux" },
+	{},
+};
+
+static struct platform_driver stm32_dmamux_driver = {
+	.probe	= stm32_dmamux_probe,
+	.driver = {
+		.name = "stm32-dmamux",
+		.of_match_table = stm32_dmamux_match,
+	},
+};
+
+static int __init stm32_dmamux_init(void)
+{
+	return platform_driver_register(&stm32_dmamux_driver);
+}
+arch_initcall(stm32_dmamux_init);
diff --git a/include/linux/dma/stm32-dmamux.h b/include/linux/dma/stm32-dmamux.h
new file mode 100644
index 0000000..3a4eae1
--- /dev/null
+++ b/include/linux/dma/stm32-dmamux.h
@@ -0,0 +1,21 @@
+/*
+ * stm32-dmamux.h
+ *
+ * Copyright (C) M'Boumba Cedric Madianga 2017
+ * Author:  M'Boumba Cedric Madianga <cedric.madianga@gmail.com>
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#ifndef __DMA_STM32_DMAMUX_H
+#define __DMA_STM32_DMAMUX_H
+
+#if defined(CONFIG_STM32_DMAMUX)
+int stm32_dmamux_set_config(struct device *dev, void *route_data, u32 chan_id);
+#else
+int stm32_dmamux_set_config(struct device *dev, void *route_data, u32 chan_id)
+{
+	return -ENODEV;
+}
+#endif /* CONFIG_STM32_DMAMUX */
+
+#endif /* __DMA_STM32_DMAMUX_H */
-- 
1.9.1

[PATCH v2 3/5] dt-bindings: stm32-dma: Add property to handle STM32 DMAMUX

[Pierre-Yves MORDRET]

This patch adds an optional property needed for STM32 DMA controller
addressed via STM32 DMAMUX.

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
---
 Version history:
    v2:
        * Typo fix
---
---
 Documentation/devicetree/bindings/dma/stm32-dma.txt | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/dma/stm32-dma.txt b/Documentation/devicetree/bindings/dma/stm32-dma.txt
index 4408af6..340c918 100644
--- a/Documentation/devicetree/bindings/dma/stm32-dma.txt
+++ b/Documentation/devicetree/bindings/dma/stm32-dma.txt
@@ -16,6 +16,9 @@ Optional properties:
 - resets: Reference to a reset controller asserting the DMA controller
 - st,mem2mem: boolean; if defined, it indicates that the controller supports
   memory-to-memory transfer
+- st,dmamux: boolean; if defined, it indicates that the controller is behind a
+  DMA multiplexer. In that case, using dma instances doesn't work for DMA
+  clients. They have to use dma-router instances.
 
 Example:
 
@@ -39,7 +42,7 @@ Example:
 * DMA client
 
 DMA clients connected to the STM32 DMA controller must use the format
-described in the dma.txt file, using a five-cell specifier for each
+described in the dma.txt file, using a four-cell specifier for each
 channel: a phandle to the DMA controller plus the following four integer cells:
 
 1. The channel id
-- 
1.9.1

Re: [PATCH v2 3/5] dt-bindings: stm32-dma: Add property to handle STM32 DMAMUX

[Rob Herring]

On Fri, Jun 23, 2017 at 03:00:51PM +0200, Pierre-Yves MORDRET wrote:
> This patch adds an optional property needed for STM32 DMA controller
> addressed via STM32 DMAMUX.
> 
> Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
> Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
> ---
>  Version history:
>     v2:
>         * Typo fix
> ---
> ---
>  Documentation/devicetree/bindings/dma/stm32-dma.txt | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/dma/stm32-dma.txt b/Documentation/devicetree/bindings/dma/stm32-dma.txt
> index 4408af6..340c918 100644
> --- a/Documentation/devicetree/bindings/dma/stm32-dma.txt
> +++ b/Documentation/devicetree/bindings/dma/stm32-dma.txt
> @@ -16,6 +16,9 @@ Optional properties:
>  - resets: Reference to a reset controller asserting the DMA controller
>  - st,mem2mem: boolean; if defined, it indicates that the controller supports
>    memory-to-memory transfer
> +- st,dmamux: boolean; if defined, it indicates that the controller is behind a
> +  DMA multiplexer. In that case, using dma instances doesn't work for DMA
> +  clients. They have to use dma-router instances.

Won't this be obvious looking at the bindings for clients?

In any case, this should be implied by the compatible string.

Rob

Re: [PATCH v2 3/5] dt-bindings: stm32-dma: Add property to handle STM32 DMAMUX

[Pierre Yves MORDRET]

On 06/26/2017 09:33 PM, Rob Herring wrote:
> On Fri, Jun 23, 2017 at 03:00:51PM +0200, Pierre-Yves MORDRET wrote:
>> This patch adds an optional property needed for STM32 DMA controller
>> addressed via STM32 DMAMUX.
>>
>> Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
>> Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
>> ---
>>   Version history:
>>      v2:
>>          * Typo fix
>> ---
>> ---
>>   Documentation/devicetree/bindings/dma/stm32-dma.txt | 5 ++++-
>>   1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/Documentation/devicetree/bindings/dma/stm32-dma.txt b/Documentation/devicetree/bindings/dma/stm32-dma.txt
>> index 4408af6..340c918 100644
>> --- a/Documentation/devicetree/bindings/dma/stm32-dma.txt
>> +++ b/Documentation/devicetree/bindings/dma/stm32-dma.txt
>> @@ -16,6 +16,9 @@ Optional properties:
>>   - resets: Reference to a reset controller asserting the DMA controller
>>   - st,mem2mem: boolean; if defined, it indicates that the controller supports
>>     memory-to-memory transfer
>> +- st,dmamux: boolean; if defined, it indicates that the controller is behind a
>> +  DMA multiplexer. In that case, using dma instances doesn't work for DMA
>> +  clients. They have to use dma-router instances.
> 
> Won't this be obvious looking at the bindings for clients?
> 
> In any case, this should be implied by the compatible string.
> 
> Rob
> 

Not sure what you are asking here.

Py

[PATCH v2 4/5] dmaengine: stm32-dma: Add support for STM32 DMAMUX

[Pierre-Yves MORDRET]

This patch adds support for STM32 DMAMUX.
When the STM32 DMA controller is behind a STM32 DMAMUX the request line
number has not to be handled by DMA but DMAMUX.

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
---
 Version history:
    v2:
        * Use DMAMUX Configuration API's
        * DMAXMUX(if used) provides ChannelID
---
---
 drivers/dma/stm32-dma.c | 44 +++++++++++++++++++++++++++++++-------------
 1 file changed, 31 insertions(+), 13 deletions(-)

diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c
index 786fc8f..a9e5884 100644
--- a/drivers/dma/stm32-dma.c
+++ b/drivers/dma/stm32-dma.c
@@ -13,6 +13,7 @@
 #include <linux/delay.h>
 #include <linux/dmaengine.h>
 #include <linux/dma-mapping.h>
+#include <linux/dma/stm32-dmamux.h>
 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/jiffies.h>
@@ -179,6 +180,7 @@ struct stm32_dma_device {
 	struct clk *clk;
 	struct reset_control *rst;
 	bool mem2mem;
+	bool dmamux;
 	struct stm32_dma_chan chan[STM32_DMA_MAX_CHANNELS];
 };
 
@@ -272,12 +274,18 @@ static int stm32_dma_slave_config(struct dma_chan *c,
 				  struct dma_slave_config *config)
 {
 	struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
+	int ret = 0;
 
 	memcpy(&chan->dma_sconfig, config, sizeof(*config));
 
-	chan->config_init = true;
+	if (c->router)
+		ret = stm32_dmamux_set_config(c->router->dev, c->route_data,
+					      c->chan_id);
 
-	return 0;
+	if (!ret)
+		chan->config_init = true;
+
+	return ret;
 }
 
 static u32 stm32_dma_irq_status(struct stm32_dma_chan *chan)
@@ -998,18 +1006,26 @@ static struct dma_chan *stm32_dma_of_xlate(struct of_phandle_args *dma_spec,
 	cfg.stream_config = dma_spec->args[2];
 	cfg.threshold = dma_spec->args[3];
 
-	if ((cfg.channel_id >= STM32_DMA_MAX_CHANNELS) ||
-	    (cfg.request_line >= STM32_DMA_MAX_REQUEST_ID)) {
-		dev_err(dev, "Bad channel and/or request id\n");
-		return NULL;
-	}
-
-	chan = &dmadev->chan[cfg.channel_id];
+	if (dmadev->dmamux) {
+		c = dma_get_any_slave_channel(&dmadev->ddev);
+		if (!c) {
+			dev_err(dev, "No more channel avalaible\n");
+			return NULL;
+		}
+		chan = &dmadev->chan[c->chan_id];
+	} else {
+		if ((cfg.channel_id >= STM32_DMA_MAX_CHANNELS) ||
+		    (cfg.request_line >= STM32_DMA_MAX_REQUEST_ID)) {
+			dev_err(dev, "Bad channel and/or request id\n");
+			return NULL;
+		}
 
-	c = dma_get_slave_channel(&chan->vchan.chan);
-	if (!c) {
-		dev_err(dev, "No more channels available\n");
-		return NULL;
+		chan = &dmadev->chan[cfg.channel_id];
+		c = dma_get_slave_channel(&chan->vchan.chan);
+		if (!c) {
+			dev_err(dev, "No more channel avalaible\n");
+			return NULL;
+		}
 	}
 
 	stm32_dma_set_config(chan, &cfg);
@@ -1058,6 +1074,8 @@ static int stm32_dma_probe(struct platform_device *pdev)
 	dmadev->mem2mem = of_property_read_bool(pdev->dev.of_node,
 						"st,mem2mem");
 
+	dmadev->dmamux = of_property_read_bool(pdev->dev.of_node, "st,dmamux");
+
 	dmadev->rst = devm_reset_control_get(&pdev->dev, NULL);
 	if (!IS_ERR(dmadev->rst)) {
 		reset_control_assert(dmadev->rst);
-- 
1.9.1

[PATCH v2 5/5] ARM: configs: stm32: Add DMAMUX support in STM32 defconfig

[Pierre-Yves MORDRET]

This patch adds DMAMUX support in STM32 defconfig file

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
---
 Version history:
    v2: None
---
---
 arch/arm/configs/stm32_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/stm32_defconfig b/arch/arm/configs/stm32_defconfig
index a097538..15fbaba 100644
--- a/arch/arm/configs/stm32_defconfig
+++ b/arch/arm/configs/stm32_defconfig
@@ -64,6 +64,7 @@ CONFIG_RTC_CLASS=y
 CONFIG_RTC_DRV_STM32=y
 CONFIG_DMADEVICES=y
 CONFIG_STM32_DMA=y
+CONFIG_STM32_DMAMUX=y
 CONFIG_IIO=y
 CONFIG_STM32_ADC_CORE=y
 CONFIG_STM32_ADC=y
-- 
1.9.1