[PATCH v2 0/2] xilinx_dma: Add external reset control

[PATCH v2 0/2] xilinx_dma: Add external reset control

[Ramiro Oliveira]

This patchset adds support for controlling an external reset line. Since
this reset line is optional it won't break compatibility.

v2:
 - Re-order headers
 - Remove deprecated function
 - Remove reset naming

Ramiro Oliveira (2):
  dma: xilinx: Edit device tree bindings documentation
  dma: xilinx: Add reset support

 .../devicetree/bindings/dma/xilinx/xilinx_dma.txt  |  2 ++
 drivers/dma/xilinx/xilinx_dma.c                    | 24 ++++++++++++++++++----
 2 files changed, 22 insertions(+), 4 deletions(-)

-- 
2.11.0

[PATCH v2 1/2] dma: xilinx: Edit device tree bindings documentation

[Ramiro Oliveira]

Add reset property documentation for Xilinx DMA

Signed-off-by: Ramiro Oliveira <roliveir@synopsys.com>
---
 Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt b/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
index a2b8bfaec43c..96c469a4717f 100644
--- a/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
+++ b/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
@@ -40,6 +40,7 @@ Required properties for VDMA:
 Optional properties:
 - xlnx,include-sg: Tells configured for Scatter-mode in
 	the hardware.
+- resets : External reset specifier. See ../../reset/reset.txt for details.
 Optional properties for AXI DMA:
 - xlnx,mcdma: Tells whether configured for multi-channel mode in the hardware.
 Optional properties for VDMA:
@@ -83,6 +84,7 @@ axi_vdma_0: axivdma at 40030000 {
 	clocks = <&clk 0>, <&clk 1>, <&clk 2>, <&clk 3>, <&clk 4>;
 	clock-names = "s_axi_lite_aclk", "m_axi_mm2s_aclk", "m_axi_s2mm_aclk",
 		      "m_axis_mm2s_aclk", "s_axis_s2mm_aclk";
+	resets = <&rst 2>;
 	dma-channel at 40030000 {
 		compatible = "xlnx,axi-vdma-mm2s-channel";
 		interrupts = < 0 54 4 >;
-- 
2.11.0

[PATCH v2 1/2] dma: xilinx: Edit device tree bindings documentation

[Rob Herring]

On Mon, Mar 06, 2017 at 12:17:38PM +0000, Ramiro Oliveira wrote:
> Add reset property documentation for Xilinx DMA
> 
> Signed-off-by: Ramiro Oliveira <roliveir@synopsys.com>
> ---
>  Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt | 2 ++
>  1 file changed, 2 insertions(+)

Acked-by: Rob Herring <robh@kernel.org>

[PATCH v2 2/2] dma: xilinx: Add reset support

[Ramiro Oliveira]

Add a DT property to control an optional external reset line

Signed-off-by: Ramiro Oliveira <roliveir@synopsys.com>
---
 drivers/dma/xilinx/xilinx_dma.c | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index 5c9f11b623ca..589cbb611bc8 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -32,20 +32,21 @@
  */
 
 #include <linux/bitops.h>
-#include <linux/dmapool.h>
+#include <linux/clk.h>
 #include <linux/dma/xilinx_dma.h>
+#include <linux/dmapool.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
 #include <linux/module.h>
 #include <linux/of_address.h>
 #include <linux/of_dma.h>
-#include <linux/of_platform.h>
 #include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/reset.h>
 #include <linux/slab.h>
-#include <linux/clk.h>
-#include <linux/io-64-nonatomic-lo-hi.h>
 
 #include "../dmaengine.h"
 
@@ -409,6 +410,7 @@ struct xilinx_dma_device {
 	struct clk *rxs_clk;
 	u32 nr_channels;
 	u32 chan_id;
+	struct reset_control *rst;
 };
 
 /* Macros */
@@ -2543,6 +2545,20 @@ static int xilinx_dma_probe(struct platform_device *pdev)
 	if (IS_ERR(xdev->regs))
 		return PTR_ERR(xdev->regs);
 
+	xdev->rst = devm_reset_control_get_optional_shared(&pdev->dev, NULL);
+	if (IS_ERR(xdev->rst)) {
+		err = PTR_ERR(xdev->rst);
+		if (err == -EPROBE_DEFER)
+			return err;
+		xdev->rst = NULL;
+	} else {
+		err = reset_control_deassert(xdev->rst);
+		if (err) {
+			dev_err(xdev->dev, "error deasserting reset %d\n", err);
+			return err;
+		}
+	}
+
 	/* Retrieve the DMA engine properties from the device tree */
 	xdev->has_sg = of_property_read_bool(node, "xlnx,include-sg");
 	if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA)
-- 
2.11.0

[PATCH v2 2/2] dma: xilinx: Add reset support

[Vinod Koul]

On Mon, Mar 06, 2017 at 12:17:39PM +0000, Ramiro Oliveira wrote:
> Add a DT property to control an optional external reset line
> 
> Signed-off-by: Ramiro Oliveira <roliveir@synopsys.com>
> ---
>  drivers/dma/xilinx/xilinx_dma.c | 24 ++++++++++++++++++++----
>  1 file changed, 20 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
> index 5c9f11b623ca..589cbb611bc8 100644
> --- a/drivers/dma/xilinx/xilinx_dma.c
> +++ b/drivers/dma/xilinx/xilinx_dma.c
> @@ -32,20 +32,21 @@
>   */
>  
>  #include <linux/bitops.h>
> -#include <linux/dmapool.h>
> +#include <linux/clk.h>
>  #include <linux/dma/xilinx_dma.h>
> +#include <linux/dmapool.h>
>  #include <linux/init.h>
>  #include <linux/interrupt.h>
> +#include <linux/io-64-nonatomic-lo-hi.h>
>  #include <linux/io.h>
>  #include <linux/iopoll.h>
>  #include <linux/module.h>
>  #include <linux/of_address.h>
>  #include <linux/of_dma.h>
> -#include <linux/of_platform.h>
>  #include <linux/of_irq.h>
> +#include <linux/of_platform.h>
> +#include <linux/reset.h>
>  #include <linux/slab.h>
> -#include <linux/clk.h>
> -#include <linux/io-64-nonatomic-lo-hi.h>

this is noise in the patch, if you want to change the order feel free to
send a separate patch

>  
>  #include "../dmaengine.h"
>  
> @@ -409,6 +410,7 @@ struct xilinx_dma_device {
>  	struct clk *rxs_clk;
>  	u32 nr_channels;
>  	u32 chan_id;
> +	struct reset_control *rst;
>  };
>  
>  /* Macros */
> @@ -2543,6 +2545,20 @@ static int xilinx_dma_probe(struct platform_device *pdev)
>  	if (IS_ERR(xdev->regs))
>  		return PTR_ERR(xdev->regs);
>  
> +	xdev->rst = devm_reset_control_get_optional_shared(&pdev->dev, NULL);
> +	if (IS_ERR(xdev->rst)) {
> +		err = PTR_ERR(xdev->rst);
> +		if (err == -EPROBE_DEFER)
> +			return err;
> +		xdev->rst = NULL;

is this optional, how will it work if you can't bring device out if reset

> +	} else {
> +		err = reset_control_deassert(xdev->rst);
> +		if (err) {
> +			dev_err(xdev->dev, "error deasserting reset %d\n", err);
> +			return err;
> +		}
> +	}
> +
>  	/* Retrieve the DMA engine properties from the device tree */
>  	xdev->has_sg = of_property_read_bool(node, "xlnx,include-sg");
>  	if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA)
> -- 
> 2.11.0
> 
> 

-- 
~Vinod