Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma

Pull slave-dmaengine updates from Vinod Koul:
 "This time we have dmatest improvements from Andy along with dw_dmac
  fixes.  He has also done support for acpi for dmanegine.

  Also we have bunch of fixes going in DT support for dmanegine for
  various folks.  Then Haswell and other ioat changes from Dave and
  SUDMAC support from Shimoda."

* 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma: (53 commits)
  dma: tegra: implement suspend/resume callbacks
  dma:of: Use a mutex to protect the of_dma_list
  dma: of: Fix of_node reference leak
  dmaengine: sirf: move driver init from module_init to subsys_initcall
  sudmac: add support for SUDMAC
  dma: sh: add Kconfig
  at_hdmac: move to generic DMA binding
  ioatdma: ioat3_alloc_sed can be static
  ioatdma: Adding write back descriptor error status support for ioatdma 3.3
  ioatdma: S1200 platforms ioatdma channel 2 and 3 falsely advertise RAID cap
  ioatdma: Adding support for 16 src PQ ops and super extended descriptors
  ioatdma: Removing hw bug workaround for CB3.x .2 and earlier
  dw_dmac: add ACPI support
  dmaengine: call acpi_dma_request_slave_channel as well
  dma: acpi-dma: introduce ACPI DMA helpers
  dma: of: Remove unnecessary list_empty check
  DMA: OF: Check properties value before running be32_to_cpup() on it
  DMA: of: Constant names
  ioatdma: skip silicon bug workaround for pq_align for cb3.3
  ioatdma: Removing PQ val disable for cb3.3
  ...

39 files changed, 3215 insertions, 517 deletions

diff --git a/Documentation/acpi/enumeration.txt b/Documentation/acpi/enumeration.txt
index b0d541042ac..d9be7a97dff 100644
--- a/Documentation/acpi/enumeration.txt
+++ b/Documentation/acpi/enumeration.txt
@@ -66,6 +66,83 @@ the ACPI device explicitly to acpi_platform_device_ids list defined in
 drivers/acpi/acpi_platform.c. This limitation is only for the platform
 devices, SPI and I2C devices are created automatically as described below.
 
+DMA support
+~~~~~~~~~~~
+DMA controllers enumerated via ACPI should be registered in the system to
+provide generic access to their resources. For example, a driver that would
+like to be accessible to slave devices via generic API call
+dma_request_slave_channel() must register itself at the end of the probe
+function like this:
+
+	err = devm_acpi_dma_controller_register(dev, xlate_func, dw);
+	/* Handle the error if it's not a case of !CONFIG_ACPI */
+
+and implement custom xlate function if needed (usually acpi_dma_simple_xlate()
+is enough) which converts the FixedDMA resource provided by struct
+acpi_dma_spec into the corresponding DMA channel. A piece of code for that case
+could look like:
+
+	#ifdef CONFIG_ACPI
+	struct filter_args {
+		/* Provide necessary information for the filter_func */
+		...
+	};
+
+	static bool filter_func(struct dma_chan *chan, void *param)
+	{
+		/* Choose the proper channel */
+		...
+	}
+
+	static struct dma_chan *xlate_func(struct acpi_dma_spec *dma_spec,
+			struct acpi_dma *adma)
+	{
+		dma_cap_mask_t cap;
+		struct filter_args args;
+
+		/* Prepare arguments for filter_func */
+		...
+		return dma_request_channel(cap, filter_func, &args);
+	}
+	#else
+	static struct dma_chan *xlate_func(struct acpi_dma_spec *dma_spec,
+			struct acpi_dma *adma)
+	{
+		return NULL;
+	}
+	#endif
+
+dma_request_slave_channel() will call xlate_func() for each registered DMA
+controller. In the xlate function the proper channel must be chosen based on
+information in struct acpi_dma_spec and the properties of the controller
+provided by struct acpi_dma.
+
+Clients must call dma_request_slave_channel() with the string parameter that
+corresponds to a specific FixedDMA resource. By default "tx" means the first
+entry of the FixedDMA resource array, "rx" means the second entry. The table
+below shows a layout:
+
+	Device (I2C0)
+	{
+		...
+		Method (_CRS, 0, NotSerialized)
+		{
+			Name (DBUF, ResourceTemplate ()
+			{
+				FixedDMA (0x0018, 0x0004, Width32bit, _Y48)
+				FixedDMA (0x0019, 0x0005, Width32bit, )
+			})
+		...
+		}
+	}
+
+So, the FixedDMA with request line 0x0018 is "tx" and next one is "rx" in
+this example.
+
+In robust cases the client unfortunately needs to call
+acpi_dma_request_slave_chan_by_index() directly and therefore choose the
+specific FixedDMA resource by its index.
+
 SPI serial bus support
 ~~~~~~~~~~~~~~~~~~~~~~
 Slave devices behind SPI bus have SpiSerialBus resource attached to them.
diff --git a/Documentation/devicetree/bindings/dma/atmel-dma.txt b/Documentation/devicetree/bindings/dma/atmel-dma.txt
index 3c046ee6e8b..c80e8a3402f 100644
--- a/Documentation/devicetree/bindings/dma/atmel-dma.txt
+++ b/Documentation/devicetree/bindings/dma/atmel-dma.txt
@@ -1,14 +1,39 @@
 * Atmel Direct Memory Access Controller (DMA)
 
 Required properties:
-- compatible: Should be "atmel,<chip>-dma"
-- reg: Should contain DMA registers location and length
-- interrupts: Should contain DMA interrupt
+- compatible: Should be "atmel,<chip>-dma".
+- reg: Should contain DMA registers location and length.
+- interrupts: Should contain DMA interrupt.
+- #dma-cells: Must be <2>, used to represent the number of integer cells in
+the dmas property of client devices.
 
-Examples:
+Example:
 
-dma@ffffec00 {
+dma0: dma@ffffec00 {
 	compatible = "atmel,at91sam9g45-dma";
 	reg = <0xffffec00 0x200>;
 	interrupts = <21>;
+	#dma-cells = <2>;
+};
+
+DMA clients connected to the Atmel DMA controller must use the format
+described in the dma.txt file, using a three-cell specifier for each channel:
+a phandle plus two interger cells.
+The three cells in order are:
+
+1. A phandle pointing to the DMA controller.
+2. The memory interface (16 most significant bits), the peripheral interface
+(16 less significant bits).
+3. The peripheral identifier for the hardware handshaking interface. The
+identifier can be different for tx and rx.
+
+Example:
+
+i2c0@i2c@f8010000 {
+	compatible = "atmel,at91sam9x5-i2c";
+	reg = <0xf8010000 0x100>;
+	interrupts = <9 4 6>;
+	dmas = <&dma0 1 7>,
+	       <&dma0 1 8>;
+	dma-names = "tx", "rx";
 };
diff --git a/Documentation/dmatest.txt b/Documentation/dmatest.txt
new file mode 100644
index 00000000000..279ac0a8c5b
--- /dev/null
+++ b/Documentation/dmatest.txt
@@ -0,0 +1,81 @@
+				DMA Test Guide
+				==============
+
+		Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+
+This small document introduces how to test DMA drivers using dmatest module.
+
+	Part 1 - How to build the test module
+
+The menuconfig contains an option that could be found by following path:
+	Device Drivers -> DMA Engine support -> DMA Test client
+
+In the configuration file the option called CONFIG_DMATEST. The dmatest could
+be built as module or inside kernel. Let's consider those cases.
+
+	Part 2 - When dmatest is built as a module...
+
+After mounting debugfs and loading the module, the /sys/kernel/debug/dmatest
+folder with nodes will be created. They are the same as module parameters with
+addition of the 'run' node that controls run and stop phases of the test.
+
+Note that in this case test will not run on load automatically.
+
+Example of usage:
+	% echo dma0chan0 > /sys/kernel/debug/dmatest/channel
+	% echo 2000 > /sys/kernel/debug/dmatest/timeout
+	% echo 1 > /sys/kernel/debug/dmatest/iterations
+	% echo 1 > /sys/kernel/debug/dmatest/run
+
+Hint: available channel list could be extracted by running the following
+command:
+	% ls -1 /sys/class/dma/
+
+After a while you will start to get messages about current status or error like
+in the original code.
+
+Note that running a new test will stop any in progress test.
+
+The following command should return actual state of the test.
+	% cat /sys/kernel/debug/dmatest/run
+
+To wait for test done the user may perform a busy loop that checks the state.
+
+	% while [ $(cat /sys/kernel/debug/dmatest/run) = "Y" ]
+	> do
+	> 	echo -n "."
+	> 	sleep 1
+	> done
+	> echo
+
+	Part 3 - When built-in in the kernel...
+
+The module parameters that is supplied to the kernel command line will be used
+for the first performed test. After user gets a control, the test could be
+interrupted or re-run with same or different parameters. For the details see
+the above section "Part 2 - When dmatest is built as a module..."
+
+In both cases the module parameters are used as initial values for the test case.
+You always could check them at run-time by running
+	% grep -H . /sys/module/dmatest/parameters/*
+
+	Part 4 - Gathering the test results
+
+The module provides a storage for the test results in the memory. The gathered
+data could be used after test is done.
+
+The special file 'results' in the debugfs represents gathered data of the in
+progress test. The messages collected are printed to the kernel log as well.
+
+Example of output:
+	% cat /sys/kernel/debug/dmatest/results
+	dma0chan0-copy0: #1: No errors with src_off=0x7bf dst_off=0x8ad len=0x3fea (0)
+
+The message format is unified across the different types of errors. A number in
+the parens represents additional information, e.g. error code, error counter,
+or status.
+
+Comparison between buffers is stored to the dedicated structure.
+
+Note that the verify result is now accessible only via file 'results' in the
+debugfs.
diff --git a/arch/arm/mach-omap2/dma.c b/arch/arm/mach-omap2/dma.c
index dab9fc014b9..49fd0d501c9 100644
--- a/arch/arm/mach-omap2/dma.c
+++ b/arch/arm/mach-omap2/dma.c
@@ -28,6 +28,7 @@
 #include <linux/init.h>
 #include <linux/device.h>
 #include <linux/dma-mapping.h>
+#include <linux/of.h>
 #include <linux/omap-dma.h>
 
 #include "soc.h"
@@ -304,6 +305,9 @@ static int __init omap2_system_dma_init(void)
 	if (res)
 		return res;
 
+	if (of_have_populated_dt())
+		return res;
+
 	pdev = platform_device_register_full(&omap_dma_dev_info);
 	if (IS_ERR(pdev))
 		return PTR_ERR(pdev);
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index aeaea32bcfd..e9924898043 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -63,8 +63,6 @@ config INTEL_IOATDMA
 	depends on PCI && X86
 	select DMA_ENGINE
 	select DCA
-	select ASYNC_TX_DISABLE_PQ_VAL_DMA
-	select ASYNC_TX_DISABLE_XOR_VAL_DMA
 	help
 	  Enable support for the Intel(R) I/OAT DMA engine present
 	  in recent Intel Xeon chipsets.
@@ -174,15 +172,7 @@ config TEGRA20_APB_DMA
 	  This DMA controller transfers data from memory to peripheral fifo
 	  or vice versa. It does not support memory to memory data transfer.
 
-
-
-config SH_DMAE
-	tristate "Renesas SuperH DMAC support"
-	depends on (SUPERH && SH_DMA) || (ARM && ARCH_SHMOBILE)
-	depends on !SH_DMA_API
-	select DMA_ENGINE
-	help
-	  Enable support for the Renesas SuperH DMA controllers.
+source "drivers/dma/sh/Kconfig"
 
 config COH901318
 	bool "ST-Ericsson COH901318 DMA support"
@@ -328,6 +318,10 @@ config DMA_ENGINE
 config DMA_VIRTUAL_CHANNELS
 	tristate
 
+config DMA_ACPI
+	def_bool y
+	depends on ACPI
+
 config DMA_OF
 	def_bool y
 	depends on OF
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index 488e3ff85b5..a2b0df591f9 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -3,6 +3,7 @@ ccflags-$(CONFIG_DMADEVICES_VDEBUG) += -DVERBOSE_DEBUG
 
 obj-$(CONFIG_DMA_ENGINE) += dmaengine.o
 obj-$(CONFIG_DMA_VIRTUAL_CHANNELS) += virt-dma.o
+obj-$(CONFIG_DMA_ACPI) += acpi-dma.o
 obj-$(CONFIG_DMA_OF) += of-dma.o
 
 obj-$(CONFIG_NET_DMA) += iovlock.o
@@ -18,7 +19,7 @@ obj-$(CONFIG_DW_DMAC) += dw_dmac.o
 obj-$(CONFIG_AT_HDMAC) += at_hdmac.o
 obj-$(CONFIG_MX3_IPU) += ipu/
 obj-$(CONFIG_TXX9_DMAC) += txx9dmac.o
-obj-$(CONFIG_SH_DMAE) += sh/
+obj-$(CONFIG_SH_DMAE_BASE) += sh/
 obj-$(CONFIG_COH901318) += coh901318.o coh901318_lli.o
 obj-$(CONFIG_AMCC_PPC440SPE_ADMA) += ppc4xx/
 obj-$(CONFIG_IMX_SDMA) += imx-sdma.o
diff --git a/drivers/dma/acpi-dma.c b/drivers/dma/acpi-dma.c
new file mode 100644
index 00000000000..ba6fc62e965
--- /dev/null
+++ b/drivers/dma/acpi-dma.c
@@ -0,0 +1,279 @@
+/*
+ * ACPI helpers for DMA request / controller
+ *
+ * Based on of-dma.c
+ *
+ * Copyright (C) 2013, Intel Corporation
+ * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+ *
+ * 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/device.h>
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/acpi.h>
+#include <linux/acpi_dma.h>
+
+static LIST_HEAD(acpi_dma_list);
+static DEFINE_MUTEX(acpi_dma_lock);
+
+/**
+ * acpi_dma_controller_register - Register a DMA controller to ACPI DMA helpers
+ * @dev:		struct device of DMA controller
+ * @acpi_dma_xlate:	translation function which converts a dma specifier
+ *			into a dma_chan structure
+ * @data		pointer to controller specific data to be used by
+ *			translation function
+ *
+ * Returns 0 on success or appropriate errno value on error.
+ *
+ * Allocated memory should be freed with appropriate acpi_dma_controller_free()
+ * call.
+ */
+int acpi_dma_controller_register(struct device *dev,
+		struct dma_chan *(*acpi_dma_xlate)
+		(struct acpi_dma_spec *, struct acpi_dma *),
+		void *data)
+{
+	struct acpi_device *adev;
+	struct acpi_dma	*adma;
+
+	if (!dev || !acpi_dma_xlate)
+		return -EINVAL;
+
+	/* Check if the device was enumerated by ACPI */
+	if (!ACPI_HANDLE(dev))
+		return -EINVAL;
+
+	if (acpi_bus_get_device(ACPI_HANDLE(dev), &adev))
+		return -EINVAL;
+
+	adma = kzalloc(sizeof(*adma), GFP_KERNEL);
+	if (!adma)
+		return -ENOMEM;
+
+	adma->dev = dev;
+	adma->acpi_dma_xlate = acpi_dma_xlate;
+	adma->data = data;
+
+	/* Now queue acpi_dma controller structure in list */
+	mutex_lock(&acpi_dma_lock);
+	list_add_tail(&adma->dma_controllers, &acpi_dma_list);
+	mutex_unlock(&acpi_dma_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(acpi_dma_controller_register);
+
+/**
+ * acpi_dma_controller_free - Remove a DMA controller from ACPI DMA helpers list
+ * @dev:	struct device of DMA controller
+ *
+ * Memory allocated by acpi_dma_controller_register() is freed here.
+ */
+int acpi_dma_controller_free(struct device *dev)
+{
+	struct acpi_dma *adma;
+
+	if (!dev)
+		return -EINVAL;
+
+	mutex_lock(&acpi_dma_lock);
+
+	list_for_each_entry(adma, &acpi_dma_list, dma_controllers)
+		if (adma->dev == dev) {
+			list_del(&adma->dma_controllers);
+			mutex_unlock(&acpi_dma_lock);
+			kfree(adma);
+			return 0;
+		}
+
+	mutex_unlock(&acpi_dma_lock);
+	return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(acpi_dma_controller_free);
+
+static void devm_acpi_dma_release(struct device *dev, void *res)
+{
+	acpi_dma_controller_free(dev);
+}
+
+/**
+ * devm_acpi_dma_controller_register - resource managed acpi_dma_controller_register()
+ * @dev:		device that is registering this DMA controller
+ * @acpi_dma_xlate:	translation function
+ * @data		pointer to controller specific data
+ *
+ * Managed acpi_dma_controller_register(). DMA controller registered by this
+ * function are automatically freed on driver detach. See
+ * acpi_dma_controller_register() for more information.
+ */
+int devm_acpi_dma_controller_register(struct device *dev,
+		struct dma_chan *(*acpi_dma_xlate)
+		(struct acpi_dma_spec *, struct acpi_dma *),
+		void *data)
+{
+	void *res;
+	int ret;
+
+	res = devres_alloc(devm_acpi_dma_release, 0, GFP_KERNEL);
+	if (!res)
+		return -ENOMEM;
+
+	ret = acpi_dma_controller_register(dev, acpi_dma_xlate, data);
+	if (ret) {
+		devres_free(res);
+		return ret;
+	}
+	devres_add(dev, res);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_acpi_dma_controller_register);
+
+/**
+ * devm_acpi_dma_controller_free - resource managed acpi_dma_controller_free()
+ *
+ * Unregister a DMA controller registered with
+ * devm_acpi_dma_controller_register(). Normally this function will not need to
+ * be called and the resource management code will ensure that the resource is
+ * freed.
+ */
+void devm_acpi_dma_controller_free(struct device *dev)
+{
+	WARN_ON(devres_destroy(dev, devm_acpi_dma_release, NULL, NULL));
+}
+EXPORT_SYMBOL_GPL(devm_acpi_dma_controller_free);
+
+struct acpi_dma_parser_data {
+	struct acpi_dma_spec dma_spec;
+	size_t index;
+	size_t n;
+};
+
+/**
+ * acpi_dma_parse_fixed_dma - Parse FixedDMA ACPI resources to a DMA specifier
+ * @res:	struct acpi_resource to get FixedDMA resources from
+ * @data:	pointer to a helper struct acpi_dma_parser_data
+ */
+static int acpi_dma_parse_fixed_dma(struct acpi_resource *res, void *data)
+{
+	struct acpi_dma_parser_data *pdata = data;
+
+	if (res->type == ACPI_RESOURCE_TYPE_FIXED_DMA) {
+		struct acpi_resource_fixed_dma *dma = &res->data.fixed_dma;
+
+		if (pdata->n++ == pdata->index) {
+			pdata->dma_spec.chan_id = dma->channels;
+			pdata->dma_spec.slave_id = dma->request_lines;
+		}
+	}
+
+	/* Tell the ACPI core to skip this resource */
+	return 1;
+}
+
+/**
+ * acpi_dma_request_slave_chan_by_index - Get the DMA slave channel
+ * @dev:	struct device to get DMA request from
+ * @index:	index of FixedDMA descriptor for @dev
+ *
+ * Returns pointer to appropriate dma channel on success or NULL on error.
+ */
+struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev,
+		size_t index)
+{
+	struct acpi_dma_parser_data pdata;
+	struct acpi_dma_spec *dma_spec = &pdata.dma_spec;
+	struct list_head resource_list;
+	struct acpi_device *adev;
+	struct acpi_dma *adma;
+	struct dma_chan *chan = NULL;
+
+	/* Check if the device was enumerated by ACPI */
+	if (!dev || !ACPI_HANDLE(dev))
+		return NULL;
+
+	if (acpi_bus_get_device(ACPI_HANDLE(dev), &adev))
+		return NULL;
+
+	memset(&pdata, 0, sizeof(pdata));
+	pdata.index = index;
+
+	/* Initial values for the request line and channel */
+	dma_spec->chan_id = -1;
+	dma_spec->slave_id = -1;
+
+	INIT_LIST_HEAD(&resource_list);
+	acpi_dev_get_resources(adev, &resource_list,
+			acpi_dma_parse_fixed_dma, &pdata);
+	acpi_dev_free_resource_list(&resource_list);
+
+	if (dma_spec->slave_id < 0 || dma_spec->chan_id < 0)
+		return NULL;
+
+	mutex_lock(&acpi_dma_lock);
+
+	list_for_each_entry(adma, &acpi_dma_list, dma_controllers) {
+		dma_spec->dev = adma->dev;
+		chan = adma->acpi_dma_xlate(dma_spec, adma);
+		if (chan)
+			break;
+	}
+
+	mutex_unlock(&acpi_dma_lock);
+	return chan;
+}
+EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_index);
+
+/**
+ * acpi_dma_request_slave_chan_by_name - Get the DMA slave channel
+ * @dev:	struct device to get DMA request from
+ * @name:	represents corresponding FixedDMA descriptor for @dev
+ *
+ * In order to support both Device Tree and ACPI in a single driver we
+ * translate the names "tx" and "rx" here based on the most common case where
+ * the first FixedDMA descriptor is TX and second is RX.
+ *
+ * Returns pointer to appropriate dma channel on success or NULL on error.
+ */
+struct dma_chan *acpi_dma_request_slave_chan_by_name(struct device *dev,
+		const char *name)
+{
+	size_t index;
+
+	if (!strcmp(name, "tx"))
+		index = 0;
+	else if (!strcmp(name, "rx"))
+		index = 1;
+	else
+		return NULL;
+
+	return acpi_dma_request_slave_chan_by_index(dev, index);
+}
+EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_name);
+
+/**
+ * acpi_dma_simple_xlate - Simple ACPI DMA engine translation helper
+ * @dma_spec: pointer to ACPI DMA specifier
+ * @adma: pointer to ACPI DMA controller data
+ *
+ * A simple translation function for ACPI based devices. Passes &struct
+ * dma_spec to the DMA controller driver provided filter function. Returns
+ * pointer to the channel if found or %NULL otherwise.
+ */
+struct dma_chan *acpi_dma_simple_xlate(struct acpi_dma_spec *dma_spec,
+		struct acpi_dma *adma)
+{
+	struct acpi_dma_filter_info *info = adma->data;
+
+	if (!info || !info->filter_fn)
+		return NULL;
+
+	return dma_request_channel(info->dma_cap, info->filter_fn, dma_spec);
+}
+EXPORT_SYMBOL_GPL(acpi_dma_simple_xlate);
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 88cfc61329d..e923cda930f 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -24,6 +24,7 @@
 #include <linux/slab.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
+#include <linux/of_dma.h>
 
 #include "at_hdmac_regs.h"
 #include "dmaengine.h"
@@ -677,7 +678,7 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 		ctrlb |=  ATC_DST_ADDR_MODE_FIXED
 			| ATC_SRC_ADDR_MODE_INCR
 			| ATC_FC_MEM2PER
-			| ATC_SIF(AT_DMA_MEM_IF) | ATC_DIF(AT_DMA_PER_IF);
+			| ATC_SIF(atchan->mem_if) | ATC_DIF(atchan->per_if);
 		reg = sconfig->dst_addr;
 		for_each_sg(sgl, sg, sg_len, i) {
 			struct at_desc	*desc;
@@ -716,7 +717,7 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 		ctrlb |=  ATC_DST_ADDR_MODE_INCR
 			| ATC_SRC_ADDR_MODE_FIXED
 			| ATC_FC_PER2MEM
-			| ATC_SIF(AT_DMA_PER_IF) | ATC_DIF(AT_DMA_MEM_IF);
+			| ATC_SIF(atchan->per_if) | ATC_DIF(atchan->mem_if);
 
 		reg = sconfig->src_addr;
 		for_each_sg(sgl, sg, sg_len, i) {
@@ -822,8 +823,8 @@ atc_dma_cyclic_fill_desc(struct dma_chan *chan, struct at_desc *desc,
 		desc->lli.ctrlb = ATC_DST_ADDR_MODE_FIXED
 				| ATC_SRC_ADDR_MODE_INCR
 				| ATC_FC_MEM2PER
-				| ATC_SIF(AT_DMA_MEM_IF)
-				| ATC_DIF(AT_DMA_PER_IF);
+				| ATC_SIF(atchan->mem_if)
+				| ATC_DIF(atchan->per_if);
 		break;
 
 	case DMA_DEV_TO_MEM:
@@ -833,8 +834,8 @@ atc_dma_cyclic_fill_desc(struct dma_chan *chan, struct at_desc *desc,
 		desc->lli.ctrlb = ATC_DST_ADDR_MODE_INCR
 				| ATC_SRC_ADDR_MODE_FIXED
 				| ATC_FC_PER2MEM
-				| ATC_SIF(AT_DMA_PER_IF)
-				| ATC_DIF(AT_DMA_MEM_IF);
+				| ATC_SIF(atchan->per_if)
+				| ATC_DIF(atchan->mem_if);
 		break;
 
 	default:
@@ -1188,6 +1189,67 @@ static void atc_free_chan_resources(struct dma_chan *chan)
 	dev_vdbg(chan2dev(chan), "free_chan_resources: done\n");
 }
 
+#ifdef CONFIG_OF
+static bool at_dma_filter(struct dma_chan *chan, void *slave)
+{
+	struct at_dma_slave *atslave = slave;
+
+	if (atslave->dma_dev == chan->device->dev) {
+		chan->private = atslave;
+		return true;
+	} else {
+		return false;
+	}
+}
+
+static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec,
+				     struct of_dma *of_dma)
+{
+	struct dma_chan *chan;
+	struct at_dma_chan *atchan;
+	struct at_dma_slave *atslave;
+	dma_cap_mask_t mask;
+	unsigned int per_id;
+	struct platform_device *dmac_pdev;
+
+	if (dma_spec->args_count != 2)
+		return NULL;
+
+	dmac_pdev = of_find_device_by_node(dma_spec->np);
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+
+	atslave = devm_kzalloc(&dmac_pdev->dev, sizeof(*atslave), GFP_KERNEL);
+	if (!atslave)
+		return NULL;
+	/*
+	 * We can fill both SRC_PER and DST_PER, one of these fields will be
+	 * ignored depending on DMA transfer direction.
+	 */
+	per_id = dma_spec->args[1];
+	atslave->cfg = ATC_FIFOCFG_HALFFIFO | ATC_DST_H2SEL_HW
+		      | ATC_SRC_H2SEL_HW | ATC_DST_PER(per_id)
+		      | ATC_SRC_PER(per_id);
+	atslave->dma_dev = &dmac_pdev->dev;
+
+	chan = dma_request_channel(mask, at_dma_filter, atslave);
+	if (!chan)
+		return NULL;
+
+	atchan = to_at_dma_chan(chan);
+	atchan->per_if = dma_spec->args[0] & 0xff;
+	atchan->mem_if = (dma_spec->args[0] >> 16) & 0xff;
+
+	return chan;
+}
+#else
+static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec,
+				     struct of_dma *of_dma)
+{
+	return NULL;
+}
+#endif
 
 /*--  Module Management  -----------------------------------------------*/
 
@@ -1342,6 +1404,8 @@ static int __init at_dma_probe(struct platform_device *pdev)
 	for (i = 0; i < plat_dat->nr_channels; i++) {
 		struct at_dma_chan	*atchan = &atdma->chan[i];
 
+		atchan->mem_if = AT_DMA_MEM_IF;
+		atchan->per_if = AT_DMA_PER_IF;
 		atchan->chan_common.device = &atdma->dma_common;
 		dma_cookie_init(&atchan->chan_common);
 		list_add_tail(&atchan->chan_common.device_node,
@@ -1388,8 +1452,25 @@ static int __init at_dma_probe(struct platform_device *pdev)
 
 	dma_async_device_register(&atdma->dma_common);
 
+	/*
+	 * Do not return an error if the dmac node is not present in order to
+	 * not break the existing way of requesting channel with
+	 * dma_request_channel().
+	 */
+	if (pdev->dev.of_node) {
+		err = of_dma_controller_register(pdev->dev.of_node,
+						 at_dma_xlate, atdma);
+		if (err) {
+			dev_err(&pdev->dev, "could not register of_dma_controller\n");
+			goto err_of_dma_controller_register;
+		}
+	}
+
 	return 0;
 
+err_of_dma_controller_register:
+	dma_async_device_unregister(&atdma->dma_common);
+	dma_pool_destroy(atdma->dma_desc_pool);
 err_pool_create:
 	platform_set_drvdata(pdev, NULL);
 	free_irq(platform_get_irq(pdev, 0), atdma);
@@ -1406,7 +1487,7 @@ err_kfree:
 	return err;
 }
 
-static int __exit at_dma_remove(struct platform_device *pdev)
+static int at_dma_remove(struct platform_device *pdev)
 {
 	struct at_dma		*atdma = platform_get_drvdata(pdev);
 	struct dma_chan		*chan, *_chan;
@@ -1564,7 +1645,7 @@ static const struct dev_pm_ops at_dma_dev_pm_ops = {
 };
 
 static struct platform_driver at_dma_driver = {