From: Gerhard Sittig <gsi@denx.de>
To: linuxppc-dev@lists.ozlabs.org,
devicetree-discuss@lists.ozlabs.org,
Alexander Popov <a13xp0p0v88@gmail.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>,
Arnd Bergmann <arnd@arndb.de>, Vinod Koul <vinod.koul@intel.com>,
Gerhard Sittig <gsi@denx.de>, Dan Williams <djbw@fb.com>,
Anatolij Gustschin <agust@denx.de>
Subject: [PATCH RFC v2 4/5] dma: mpc512x: register for device tree channel lookup
Date: Sun, 14 Jul 2013 14:02:00 +0200 [thread overview]
Message-ID: <1373803321-11628-5-git-send-email-gsi@denx.de> (raw)
In-Reply-To: <1373803321-11628-1-git-send-email-gsi@denx.de>
register the controller for device tree based lookup of DMA channels
(non-fatal for backwards compatibility with older device trees), provide
the '#dma-cells' property in the shared mpc5121.dtsi file, and introduce
a bindings document for the MPC512x DMA controller
Signed-off-by: Gerhard Sittig <gsi@denx.de>
---
.../devicetree/bindings/dma/mpc512x-dma.txt | 55 ++++++++++++++++++++
arch/powerpc/boot/dts/mpc5121.dtsi | 1 +
drivers/dma/mpc512x_dma.c | 21 ++++++--
3 files changed, 74 insertions(+), 3 deletions(-)
create mode 100644 Documentation/devicetree/bindings/dma/mpc512x-dma.txt
diff --git a/Documentation/devicetree/bindings/dma/mpc512x-dma.txt b/Documentation/devicetree/bindings/dma/mpc512x-dma.txt
new file mode 100644
index 0000000..a4867d5
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/mpc512x-dma.txt
@@ -0,0 +1,55 @@
+* Freescale MPC512x DMA Controller
+
+The DMA controller in the Freescale MPC512x SoC can move blocks of
+memory contents between memory and peripherals or memory to memory.
+
+Refer to the "Generic DMA Controller and DMA request bindings" description
+in the dma.txt file for a more detailled discussion of the binding. The
+MPC512x DMA engine binding follows the common scheme, but doesn't provide
+support for the optional channels and requests counters (those values are
+derived from the detected hardware features) and has a fixed client
+specifier length of 1 integer cell (the value is the DMA channel, since
+the DMA controller uses a fixed assignment of request lines per channel).
+
+
+DMA controller node properties:
+
+Required properties:
+- compatible: should be "fsl,mpc5121-dma"
+- reg: address and size of the DMA controller's register set
+- interrupts: interrupt spec for the DMA controller
+
+Optional properties:
+- #dma-cells: must be <1>, describes the number of integer cells
+ needed to specify the 'dmas' property in client nodes,
+ strongly recommended since common client helper code
+ uses this property
+
+Example:
+
+ dma0: dma@14000 {
+ compatible = "fsl,mpc5121-dma";
+ reg = <0x14000 0x1800>;
+ interrupts = <65 0x8>;
+ #dma-cells = <1>;
+ };
+
+
+Client node properties:
+
+Required properties:
+- dmas: list of DMA specifiers, consisting each of a handle
+ for the DMA controller and integer cells to specify
+ the channel used within the DMA controller
+- dma-names: list of identifier strings for the DMA specifiers,
+ client device driver code uses these strings to
+ have DMA channels looked up at the controller
+
+Example:
+
+ sdhc@1500 {
+ compatible = "fsl,mpc5121-sdhc";
+ /* ... */
+ dmas = <&dma0 30>;
+ dma-names = "rx-tx";
+ };
diff --git a/arch/powerpc/boot/dts/mpc5121.dtsi b/arch/powerpc/boot/dts/mpc5121.dtsi
index bd14c00..eb0058f 100644
--- a/arch/powerpc/boot/dts/mpc5121.dtsi
+++ b/arch/powerpc/boot/dts/mpc5121.dtsi
@@ -390,6 +390,7 @@
compatible = "fsl,mpc5121-dma";
reg = <0x14000 0x1800>;
interrupts = <65 0x8>;
+ #dma-cells = <1>;
};
};
diff --git a/drivers/dma/mpc512x_dma.c b/drivers/dma/mpc512x_dma.c
index 55e6a87..84fd07b 100644
--- a/drivers/dma/mpc512x_dma.c
+++ b/drivers/dma/mpc512x_dma.c
@@ -36,6 +36,7 @@
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/of_device.h>
+#include <linux/of_dma.h>
#include <linux/of_platform.h>
#include <linux/random.h>
@@ -959,11 +960,23 @@ static int mpc_dma_probe(struct platform_device *op)
/* Register DMA engine */
dev_set_drvdata(dev, mdma);
retval = dma_async_device_register(dma);
- if (retval) {
- devm_free_irq(dev, mdma->irq, mdma);
- irq_dispose_mapping(mdma->irq);
+ if (retval)
+ goto out_irq;
+
+ /* register with OF helpers for DMA lookups (nonfatal) */
+ if (dev->of_node) {
+ retval = of_dma_controller_register(dev->of_node,
+ of_dma_xlate_by_chan_id,
+ mdma);
+ if (retval)
+ dev_warn(dev, "could not register for OF lookup\n");
}
+ return 0;
+
+out_irq:
+ devm_free_irq(dev, mdma->irq, mdma);
+ irq_dispose_mapping(mdma->irq);
return retval;
}
@@ -972,6 +985,8 @@ static int mpc_dma_remove(struct platform_device *op)
struct device *dev = &op->dev;
struct mpc_dma *mdma = dev_get_drvdata(dev);
+ if (dev->of_node)
+ of_dma_controller_free(dev->of_node);
dma_async_device_unregister(&mdma->dma);
devm_free_irq(dev, mdma->irq, mdma);
irq_dispose_mapping(mdma->irq);
--
1.7.10.4
next prev parent reply other threads:[~2013-07-14 12:02 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-12 15:26 [PATCH RFC 0/8] MPC512x DMA slave s/g support, OF DMA lookup Gerhard Sittig
2013-07-12 15:26 ` [PATCH RFC 1/8] powerpc: mpc512x_dma: add support for data transfers between memory and i/o memory Gerhard Sittig
2013-07-14 10:05 ` Lars-Peter Clausen
2013-07-14 11:07 ` Gerhard Sittig
2013-07-12 15:26 ` [PATCH RFC 2/8] dma: mpc512x: fix start condition in execute() Gerhard Sittig
2013-07-12 15:26 ` [PATCH RFC 3/8] dma: mpc512x: support 'terminate all' control request Gerhard Sittig
2013-07-12 15:26 ` [PATCH RFC 4/8] dts: mpc512x: prepare for preprocessor support Gerhard Sittig
2013-07-12 15:26 ` [PATCH RFC 5/8] dma: mpc512x: use symbolic specifiers for DMA channels Gerhard Sittig
2013-07-13 7:17 ` Arnd Bergmann
2013-07-13 14:14 ` Gerhard Sittig
2013-07-14 8:50 ` Arnd Bergmann
2013-07-14 9:53 ` Lars-Peter Clausen
2013-07-14 11:02 ` Gerhard Sittig
2013-07-12 15:26 ` [PATCH RFC 6/8] dma: of: Add common xlate function for matching by channel id Gerhard Sittig
2013-07-12 15:26 ` [PATCH RFC 7/8] dma: mpc512x: register for device tree channel lookup Gerhard Sittig
2013-07-12 15:26 ` [PATCH RFC 8/8] HACK mmc: mxcmmc: enable clocks for the MPC512x Gerhard Sittig
2013-07-12 16:45 ` [PATCH RFC 0/8] MPC512x DMA slave s/g support, OF DMA lookup Lars-Peter Clausen
2013-07-14 12:01 ` [PATCH RFC v2 0/5] " Gerhard Sittig
2013-07-14 12:01 ` [PATCH RFC v2 1/5] dma: mpc512x: re-order mpc8308 specific instructions Gerhard Sittig
2013-08-12 13:38 ` Alexander Popov
2013-07-14 12:01 ` [PATCH RFC v2 2/5] dma: mpc512x: add support for peripheral transfers Gerhard Sittig
2013-07-16 10:37 ` Lars-Peter Clausen
2013-07-17 10:42 ` Gerhard Sittig
2013-07-31 7:46 ` Alexander Popov
2013-08-12 13:37 ` Alexander Popov
2013-07-14 12:01 ` [PATCH RFC v2 3/5] dma: of: Add common xlate function for matching by channel id Gerhard Sittig
2013-10-03 14:05 ` Alexander Popov
2013-07-14 12:02 ` Gerhard Sittig [this message]
2013-10-03 14:06 ` [PATCH RFC v2 4/5] dma: mpc512x: register for device tree channel lookup Alexander Popov
2013-07-14 12:02 ` [PATCH RFC v2 5/5] HACK mmc: mxcmmc: enable clocks for the MPC512x Gerhard Sittig
2013-10-03 14:06 ` Alexander Popov
2013-07-16 9:27 ` [PATCH RFC v2 0/5] MPC512x DMA slave s/g support, OF DMA lookup Alexander Popov
2013-10-03 14:00 ` Alexander Popov
2013-10-06 10:01 ` Gerhard Sittig
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