Merge tag 'dmaengine-4.15-rc1' of git://git.infradead.org/users/vkoul/slave-dma

Pull dmaengine updates from Vinod Koul:
 "Updates for this cycle include:

   - new driver for Spreadtrum dma controller, ST MDMA and DMAMUX
     controllers

   - PM support for IMG MDC drivers

   - updates to bcm-sba-raid driver and improvements to sun6i driver

   - subsystem conversion for:
      - timers to use timer_setup()
      - remove usage of PCI pool API
      - usage of %p format specifier

   - minor updates to bunch of drivers"

* tag 'dmaengine-4.15-rc1' of git://git.infradead.org/users/vkoul/slave-dma: (49 commits)
  dmaengine: ti-dma-crossbar: Correct am335x/am43xx mux value type
  dmaengine: dmatest: warn user when dma test times out
  dmaengine: Revert "rcar-dmac: use TCRB instead of TCR for residue"
  dmaengine: stm32_mdma: activate pack/unpack feature
  dmaengine: at_hdmac: Remove unnecessary 0x prefixes before %pad
  dmaengine: coh901318: Remove unnecessary 0x prefixes before %pad
  MAINTAINERS: Step down from a co-maintaner of DW DMAC driver
  dmaengine: pch_dma: Replace PCI pool old API
  dmaengine: Convert timers to use timer_setup()
  dmaengine: sprd: Add Spreadtrum DMA driver
  dt-bindings: dmaengine: Add Spreadtrum SC9860 DMA controller
  dmaengine: sun6i: Retrieve channel count/max request from devicetree
  dmaengine: Build bcm-sba-raid driver as loadable module for iProc SoCs
  dmaengine: bcm-sba-raid: Use common GPL comment header
  dmaengine: bcm-sba-raid: Use only single mailbox channel
  dmaengine: bcm-sba-raid: serialize dma_cookie_complete() using reqs_lock
  dmaengine: pl330: fix descriptor allocation fail
  dmaengine: rcar-dmac: use TCRB instead of TCR for residue
  dmaengine: sun6i: Add support for Allwinner A64 and compatibles
  arm64: allwinner: a64: Add devicetree binding for DMA controller
  ...

Documentation/devicetree/bindings/dma/renesas,usb-dmac.txt

@@ -3,6 +3,8 @@
 Required Properties:
 -compatible: "renesas,<soctype>-usb-dmac", "renesas,usb-dmac" as fallback.
 	Examples with soctypes are:
+	  - "renesas,r8a7743-usb-dmac" (RZ/G1M)
+	  - "renesas,r8a7745-usb-dmac" (RZ/G1E)
 	  - "renesas,r8a7790-usb-dmac" (R-Car H2)
 	  - "renesas,r8a7791-usb-dmac" (R-Car M2-W)
 	  - "renesas,r8a7793-usb-dmac" (R-Car M2-N)

Documentation/devicetree/bindings/dma/sprd-dma.txt

+* Spreadtrum DMA controller
+
+This binding follows the generic DMA bindings defined in dma.txt.
+
+Required properties:
+- compatible: Should be "sprd,sc9860-dma".
+- reg: Should contain DMA registers location and length.
+- interrupts: Should contain one interrupt shared by all channel.
+- #dma-cells: must be <1>. Used to represent the number of integer
+	cells in the dmas property of client device.
+- #dma-channels : Number of DMA channels supported. Should be 32.
+- clock-names: Should contain the clock of the DMA controller.
+- clocks: Should contain a clock specifier for each entry in clock-names.
+
+Example:
+
+Controller:
+apdma: dma-controller@20100000 {
+	compatible = "sprd,sc9860-dma";
+	reg = <0x20100000 0x4000>;
+	interrupts = <GIC_SPI 50 IRQ_TYPE_LEVEL_HIGH>;
+	#dma-cells = <1>;
+	#dma-channels = <32>;
+	clock-names = "enable";
+	clocks = <&clk_ap_ahb_gates 5>;
+};
+
+
+Client:
+DMA clients connected to the Spreadtrum DMA controller must use the format
+described in the dma.txt file, using a two-cell specifier for each channel.
+The two cells in order are:
+1. A phandle pointing to the DMA controller.
+2. The channel id.
+
+spi0: spi@70a00000{
+	...
+	dma-names = "rx_chn", "tx_chn";
+	dmas = <&apdma 11>, <&apdma 12>;
+	...
+};

Documentation/devicetree/bindings/dma/stm32-dma.txt

@@ -13,6 +13,7 @@ Required properties:
 - #dma-cells : Must be <4>. See DMA client paragraph for more details.
 
 Optional properties:
+- dma-requests : Number of DMA requests supported.
 - 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
@@ -34,12 +35,13 @@ Example:
 		#dma-cells = <4>;
 		st,mem2mem;
 		resets = <&rcc 150>;
+		dma-requests = <8>;
 	};
 
 * 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

Documentation/devicetree/bindings/dma/stm32-dmamux.txt

+STM32 DMA MUX (DMA request router)
+
+Required properties:
+- compatible:	"st,stm32h7-dmamux"
+- reg:		Memory map for accessing module
+- #dma-cells:	Should be set to <3>.
+		First parameter is request line number.
+		Second is DMA channel configuration
+		Third is Fifo threshold
+		For more details about the three cells, please see
+		stm32-dma.txt documentation binding file
+- dma-masters:	Phandle pointing to the DMA controllers.
+		Several controllers are allowed. Only "st,stm32-dma" DMA
+		compatible are supported.
+
+Optional properties:
+- dma-channels : Number of DMA requests supported.
+- dma-requests : Number of DMAMUX requests supported.
+- resets: Reference to a reset controller asserting the DMA controller
+- clocks: Input clock of the DMAMUX instance.
+
+Example:
+
+/* DMA controller 1 */
+dma1: dma-controller@40020000 {
+	compatible = "st,stm32-dma";
+	reg = <0x40020000 0x400>;
+	interrupts = <11>,
+		     <12>,
+		     <13>,
+		     <14>,
+		     <15>,
+		     <16>,
+		     <17>,
+		     <47>;
+	clocks = <&timer_clk>;
+	#dma-cells = <4>;
+	st,mem2mem;
+	resets = <&rcc 150>;
+	dma-channels = <8>;
+	dma-requests = <8>;
+};
+
+/* DMA controller 1 */
+dma2: dma@40020400 {
+	compatible = "st,stm32-dma";
+	reg = <0x40020400 0x400>;
+	interrupts = <56>,
+		     <57>,
+		     <58>,
+		     <59>,
+		     <60>,
+		     <68>,
+		     <69>,
+		     <70>;
+	clocks = <&timer_clk>;
+	#dma-cells = <4>;
+	st,mem2mem;
+	resets = <&rcc 150>;
+	dma-channels = <8>;
+	dma-requests = <8>;
+};
+
+/* DMA mux */
+dmamux1: dma-router@40020800 {
+	compatible = "st,stm32h7-dmamux";
+	reg = <0x40020800 0x3c>;
+	#dma-cells = <3>;
+	dma-requests = <128>;
+	dma-channels = <16>;
+	dma-masters = <&dma1 &dma2>;
+	clocks = <&timer_clk>;
+};
+
+/* DMA client */
+usart1: serial@40011000 {
+	compatible = "st,stm32-usart", "st,stm32-uart";
+	reg = <0x40011000 0x400>;
+	interrupts = <37>;
+	clocks = <&timer_clk>;
+	dmas = <&dmamux1 41 0x414 0>,
+	       <&dmamux1 42 0x414 0>;
+	dma-names = "rx", "tx";
+};

Documentation/devicetree/bindings/dma/stm32-mdma.txt

+* STMicroelectronics STM32 MDMA controller
+
+The STM32 MDMA is a general-purpose direct memory access controller capable of
+supporting 64 independent DMA channels with 256 HW requests.
+
+Required properties:
+- compatible: Should be "st,stm32h7-mdma"
+- reg: Should contain MDMA registers location and length. This should include
+  all of the per-channel registers.
+- interrupts: Should contain the MDMA interrupt.
+- clocks: Should contain the input clock of the DMA instance.
+- resets: Reference to a reset controller asserting the DMA controller.
+- #dma-cells : Must be <5>. See DMA client paragraph for more details.
+
+Optional properties:
+- dma-channels: Number of DMA channels supported by the controller.
+- dma-requests: Number of DMA request signals supported by the controller.
+- st,ahb-addr-masks: Array of u32 mask to list memory devices addressed via
+  AHB bus.
+
+Example:
+
+	mdma1: dma@52000000 {
+		compatible = "st,stm32h7-mdma";
+		reg = <0x52000000 0x1000>;
+		interrupts = <122>;
+		clocks = <&timer_clk>;
+		resets = <&rcc 992>;
+		#dma-cells = <5>;
+		dma-channels = <16>;
+		dma-requests = <32>;
+		st,ahb-addr-masks = <0x20000000>, <0x00000000>;
+	};
+
+* DMA client
+
+DMA clients connected to the STM32 MDMA controller must use the format
+described in the dma.txt file, using a five-cell specifier for each channel:
+a phandle to the MDMA controller plus the following five integer cells:
+
+1. The request line number
+2. The priority level
+	0x00: Low
+	0x01: Medium
+	0x10: High
+	0x11: Very high
+3. A 32bit mask specifying the DMA channel configuration
+ -bit 0-1: Source increment mode
+	0x00: Source address pointer is fixed
+	0x10: Source address pointer is incremented after each data transfer
+	0x11: Source address pointer is decremented after each data transfer
+ -bit 2-3: Destination increment mode
+	0x00: Destination address pointer is fixed
+	0x10: Destination address pointer is incremented after each data
+	transfer
+	0x11: Destination address pointer is decremented after each data
+	transfer
+ -bit 8-9: Source increment offset size
+	0x00: byte (8bit)
+	0x01: half-word (16bit)
+	0x10: word (32bit)
+	0x11: double-word (64bit)
+ -bit 10-11: Destination increment offset size
+	0x00: byte (8bit)
+	0x01: half-word (16bit)
+	0x10: word (32bit)
+	0x11: double-word (64bit)
+-bit 25-18: The number of bytes to be transferred in a single transfer
+	(min = 1 byte, max = 128 bytes)
+-bit 29:28: Trigger Mode
+	0x00: Each MDMA request triggers a buffer transfer (max 128 bytes)
+	0x01: Each MDMA request triggers a block transfer (max 64K bytes)
+	0x10: Each MDMA request triggers a repeated block transfer
+	0x11: Each MDMA request triggers a linked list transfer
+4. A 32bit value specifying the register to be used to acknowledge the request
+   if no HW ack signal is used by the MDMA client
+5. A 32bit mask specifying the value to be written to acknowledge the request
+   if no HW ack signal is used by the MDMA client
+
+Example:
+
+	i2c4: i2c@5c002000 {
+		compatible = "st,stm32f7-i2c";
+		reg = <0x5c002000 0x400>;
+		interrupts = <95>,
+			     <96>;
+		clocks = <&timer_clk>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		dmas = <&mdma1 36 0x0 0x40008 0x0 0x0>,
+		       <&mdma1 37 0x0 0x40002 0x0 0x0>;
+		dma-names = "rx", "tx";
+		status = "disabled";
+	};

Documentation/devicetree/bindings/dma/sun6i-dma.txt

@@ -27,6 +27,32 @@ Example:
 		#dma-cells = <1>;
 	};
 
+------------------------------------------------------------------------------
+For A64 DMA controller:
+
+Required properties:
+- compatible:	"allwinner,sun50i-a64-dma"
+- dma-channels: Number of DMA channels supported by the controller.
+		Refer to Documentation/devicetree/bindings/dma/dma.txt
+- all properties above, i.e. reg, interrupts, clocks, resets and #dma-cells
+
+Optional properties:
+- dma-requests: Number of DMA request signals supported by the controller.
+		Refer to Documentation/devicetree/bindings/dma/dma.txt
+
+Example:
+	dma: dma-controller@1c02000 {
+		compatible = "allwinner,sun50i-a64-dma";
+		reg = <0x01c02000 0x1000>;
+		interrupts = <GIC_SPI 50 IRQ_TYPE_LEVEL_HIGH>;
+		clocks = <&ccu CLK_BUS_DMA>;
+		dma-channels = <8>;
+		dma-requests = <27>;
+		resets = <&ccu RST_BUS_DMA>;
+		#dma-cells = <1>;
+	};
+------------------------------------------------------------------------------
+
 Clients:
 
 DMA clients connected to the A31 DMA controller must use the format

MAINTAINERS

@@ -12947,7 +12947,7 @@ F:	Documentation/devicetree/bindings/arc/axs10*
 
 SYNOPSYS DESIGNWARE DMAC DRIVER
 M:	Viresh Kumar <vireshk@kernel.org>
-M:	Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+R:	Andy Shevchenko <andriy.shevchenko@linux.intel.com>
 S:	Maintained
 F:	include/linux/dma/dw.h
 F:	include/linux/platform_data/dma-dw.h

drivers/dma/Kconfig

@@ -115,7 +115,7 @@ config BCM_SBA_RAID
 	select DMA_ENGINE_RAID
 	select ASYNC_TX_DISABLE_XOR_VAL_DMA
 	select ASYNC_TX_DISABLE_PQ_VAL_DMA
-	default ARCH_BCM_IPROC
+	default m if ARCH_BCM_IPROC
 	help
 	  Enable support for Broadcom SBA RAID Engine. The SBA RAID
 	  engine is available on most of the Broadcom iProc SoCs. It
@@ -483,6 +483,35 @@ 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 STM32_MDMA
+	bool "STMicroelectronics STM32 master dma support"
+	depends on ARCH_STM32 || COMPILE_TEST
+	depends on OF
+	select DMA_ENGINE
+	select DMA_VIRTUAL_CHANNELS
+	help
+	  Enable support for the on-chip MDMA controller on STMicroelectronics
+	  STM32 platforms.
+	  If you have a board based on STM32 SoC and wish to use the master DMA
+	  say Y here.
+
+config SPRD_DMA
+	tristate "Spreadtrum DMA support"
+	depends on ARCH_SPRD || COMPILE_TEST
+	select DMA_ENGINE
+	select DMA_VIRTUAL_CHANNELS
+	help
+	  Enable support for the on-chip DMA controller on Spreadtrum platform.
+
 config S3C24XX_DMAC
 	bool "Samsung S3C24XX DMA support"
 	depends on ARCH_S3C24XX || COMPILE_TEST

drivers/dma/Makefile

@@ -60,6 +60,9 @@ 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_STM32_MDMA) += stm32-mdma.o
+obj-$(CONFIG_SPRD_DMA) += sprd-dma.o
 obj-$(CONFIG_S3C24XX_DMAC) += s3c24xx-dma.o
 obj-$(CONFIG_TXX9_DMAC) += txx9dmac.o
 obj-$(CONFIG_TEGRA20_APB_DMA) += tegra20-apb-dma.o

drivers/dma/at_hdmac_regs.h

@@ -385,7 +385,7 @@ static void vdbg_dump_regs(struct at_dma_chan *atchan) {}
 static void atc_dump_lli(struct at_dma_chan *atchan, struct at_lli *lli)
 {
 	dev_crit(chan2dev(&atchan->chan_common),
-		 "  desc: s%pad d%pad ctrl0x%x:0x%x l0x%pad\n",
+		 "desc: s%pad d%pad ctrl0x%x:0x%x l%pad\n",
 		 &lli->saddr, &lli->daddr,
 		 lli->ctrla, lli->ctrlb, &lli->dscr);
 }

drivers/dma/bcm-sba-raid.c

 /*
  * Copyright (C) 2017 Broadcom
  *
- * 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.
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
  */
 
 /*
@@ -25,11 +30,8 @@
  *
  * The Broadcom SBA RAID driver does not require any register programming
  * except submitting request to SBA hardware device via mailbox channels.
- * This driver implements a DMA device with one DMA channel using a set
- * of mailbox channels provided by Broadcom SoC specific ring manager
- * driver. To exploit parallelism (as described above), all DMA request
- * coming to SBA RAID DMA channel are broken down to smaller requests
- * and submitted to multiple mailbox channels in round-robin fashion.
+ * This driver implements a DMA device with one DMA channel using a single
+ * mailbox channel provided by Broadcom SoC specific ring manager driver.
  * For having more SBA DMA channels, we can create more SBA device nodes
  * in Broadcom SoC specific DTS based on number of hardware rings supported
  * by Broadcom SoC ring manager.
@@ -85,6 +87,7 @@
 #define SBA_CMD_GALOIS					0xe
 
 #define SBA_MAX_REQ_PER_MBOX_CHANNEL			8192
+#define SBA_MAX_MSG_SEND_PER_MBOX_CHANNEL		8
 
 /* Driver helper macros */
 #define to_sba_request(tx)		\
@@ -142,9 +145,7 @@ struct sba_device {
 	u32 max_cmds_pool_size;
 	/* Maibox client and Mailbox channels */
 	struct mbox_client client;
-	int mchans_count;
-	atomic_t mchans_current;
-	struct mbox_chan **mchans;
+	struct mbox_chan *mchan;
 	struct device *mbox_dev;
 	/* DMA device and DMA channel */
 	struct dma_device dma_dev;
@@ -200,14 +201,6 @@ static inline u32 __pure sba_cmd_pq_c_mdata(u32 d, u32 b1, u32 b0)
 
 /* ====== General helper routines ===== */
 
-static void sba_peek_mchans(struct sba_device *sba)
-{
-	int mchan_idx;
-
-	for (mchan_idx = 0; mchan_idx < sba->mchans_count; mchan_idx++)
-		mbox_client_peek_data(sba->mchans[mchan_idx]);
-}
-
 static struct sba_request *sba_alloc_request(struct sba_device *sba)
 {
 	bool found = false;
@@ -231,7 +224,7 @@ static struct sba_request *sba_alloc_request(struct sba_device *sba)
 		 * would have completed which will create more
 		 * room for new requests.
 		 */
-		sba_peek_mchans(sba);
+		mbox_client_peek_data(sba->mchan);
 		return NULL;
 	}
 
@@ -369,15 +362,11 @@ static void sba_cleanup_pending_requests(struct sba_device *sba)
 static int sba_send_mbox_request(struct sba_device *sba,
 				 struct sba_request *req)
 {
-	int mchans_idx, ret = 0;
-
-	/* Select mailbox channel in round-robin fashion */
-	mchans_idx = atomic_inc_return(&sba->mchans_current);
-	mchans_idx = mchans_idx % sba->mchans_count;
+	int ret = 0;
 
 	/* Send message for the request */
 	req->msg.error = 0;
-	ret = mbox_send_message(sba->mchans[mchans_idx], &req->msg);
+	ret = mbox_send_message(sba->mchan, &req->msg);
 	if (ret < 0) {
 		dev_err(sba->dev, "send message failed with error %d", ret);
 		return ret;
@@ -390,7 +379,7 @@ static int sba_send_mbox_request(struct sba_device *sba,
 	}
 
 	/* Signal txdone for mailbox channel */
-	mbox_client_txdone(sba->mchans[mchans_idx], ret);
+	mbox_client_txdone(sba->mchan, ret);
 
 	return ret;
 }
@@ -402,13 +391,8 @@ static void _sba_process_pending_requests(struct sba_device *sba)
 	u32 count;
 	struct sba_request *req;
 
-	/*
-	 * Process few pending requests
-	 *
-	 * For now, we process (<number_of_mailbox_channels> * 8)
-	 * number of requests at a time.
-	 */
-	count = sba->mchans_count * 8;
+	/* Process few pending requests */
+	count = SBA_MAX_MSG_SEND_PER_MBOX_CHANNEL;
 	while (!list_empty(&sba->reqs_pending_list) && count) {
 		/* Get the first pending request */
 		req = list_first_entry(&sba->reqs_pending_list,
@@ -442,7 +426,9 @@ static void sba_process_received_request(struct sba_device *sba,
 
 		WARN_ON(tx->cookie < 0);
 		if (tx->cookie > 0) {
+			spin_lock_irqsave(&sba->reqs_lock, flags);
 			dma_cookie_complete(tx);
+			spin_unlock_irqrestore(&sba->reqs_lock, flags);
 			dmaengine_desc_get_callback_invoke(tx, NULL);
 			dma_descriptor_unmap(tx);
 			tx->callback = NULL;
@@ -570,7 +556,7 @@ static enum dma_status sba_tx_status(struct dma_chan *dchan,
 	if (ret == DMA_COMPLETE)
 		return ret;
 
-	sba_peek_mchans(sba);
+	mbox_client_peek_data(sba->mchan);
 
 	return dma_cookie_status(dchan, cookie, txstate);
 }
@@ -1637,7 +1623,7 @@ static int sba_async_register(struct sba_device *sba)
 
 static int sba_probe(struct platform_device *pdev)
 {
-	int i, ret = 0, mchans_count;
+	int ret = 0;
 	struct sba_device *sba;
 	struct platform_device *mbox_pdev;
 	struct of_phandle_args args;
@@ -1650,12 +1636,11 @@ static int sba_probe(struct platform_device *pdev)
 	sba->dev = &pdev->dev;
 	platform_set_drvdata(pdev, sba);
 
-	/* Number of channels equals number of mailbox channels */
+	/* Number of mailbox channels should be atleast 1 */
 	ret = of_count_phandle_with_args(pdev->dev.of_node,
 					 "mboxes", "#mbox-cells");
 	if (ret <= 0)
 		return -ENODEV;
-	mchans_count = ret;
 
 	/* Determine SBA version from DT compatible string */
 	if (of_device_is_compatible(sba->dev->of_node, "brcm,iproc-sba"))
@@ -1688,7 +1673,7 @@ static int sba_probe(struct platform_device *pdev)
 	default:
 		return -EINVAL;
 	}
-	sba->max_req = SBA_MAX_REQ_PER_MBOX_CHANNEL * mchans_count;
+	sba->max_req = SBA_MAX_REQ_PER_MBOX_CHANNEL;
 	sba->max_cmd_per_req = sba->max_pq_srcs + 3;
 	sba->max_xor_srcs = sba->max_cmd_per_req - 1;
 	sba->max_resp_pool_size = sba->max_req * sba->hw_resp_size;
@@ -1702,55 +1687,30 @@ static int sba_probe(struct platform_device *pdev)
 	sba->client.knows_txdone	= true;
 	sba->client.tx_tout		= 0;
 
-	/* Allocate mailbox channel array */
-	sba->mchans = devm_kcalloc(&pdev->dev, mchans_count,
-				   sizeof(*sba->mchans), GFP_KERNEL);
-	if (!sba->mchans)
-		return -ENOMEM;
-
-	/* Request mailbox channels */
-	sba->mchans_count = 0;
-	for (i = 0; i < mchans_count; i++) {
-		sba->mchans[i] = mbox_request_channel(&sba->client, i);
-		if (IS_ERR(sba->mchans[i])) {
-			ret = PTR_ERR(sba->mchans[i]);
-			goto fail_free_mchans;
-		}
-		sba->mchans_count++;
+	/* Request mailbox channel */
+	sba->mchan = mbox_request_channel(&sba->client, 0);
+	if (IS_ERR(sba->mchan)) {
+		ret = PTR_ERR(sba->mchan);
+		goto fail_free_mchan;
 	}
-	atomic_set(&sba->mchans_current, 0);
 
 	/* Find-out underlying mailbox device */
 	ret = of_parse_phandle_with_args(pdev->dev.of_node,
 					 "mboxes", "#mbox-cells", 0, &args);
 	if (ret)
-		goto fail_free_mchans;
+		goto fail_free_mchan;
 	mbox_pdev = of_find_device_by_node(args.np);
 	of_node_put(args.np);
 	if (!mbox_pdev) {
 		ret = -ENODEV;
-		goto fail_free_mchans;
+		goto fail_free_mchan;
 	}
 	sba->mbox_dev = &mbox_pdev->dev;
 
-	/* All mailbox channels should be of same ring manager device */
-	for (i = 1; i < mchans_count; i++) {
-		ret = of_parse_phandle_with_args(pdev->dev.of_node,
-					 "mboxes", "#mbox-cells", i, &args);
-		if (ret)
-			goto fail_free_mchans;
-		mbox_pdev = of_find_device_by_node(args.np);
-		of_node_put(args.np);
-		if (sba->mbox_dev != &mbox_pdev->dev) {
-			ret = -EINVAL;
-			goto fail_free_mchans;
-		}
-	}
-
 	/* Prealloc channel resource */
 	ret = sba_prealloc_channel_resources(sba);
 	if (ret)
-		goto fail_free_mchans;
+		goto fail_free_mchan;
 
 	/* Check availability of debugfs */
 	if (!debugfs_initialized())
@@ -1777,24 +1737,22 @@ static int sba_probe(struct platform_device *pdev)
 		goto fail_free_resources;
 
 	/* Print device info */
-	dev_info(sba->dev, "%s using SBAv%d and %d mailbox channels",
+	dev_info(sba->dev, "%s using SBAv%d mailbox channel from %s",
 		 dma_chan_name(&sba->dma_chan), sba->ver+1,
-		 sba->mchans_count);
+		 dev_name(sba->mbox_dev));
 
 	return 0;
 
 fail_free_resources:
 	debugfs_remove_recursive(sba->root);
 	sba_freeup_channel_resources(sba);
-fail_free_mchans:
-	for (i = 0; i < sba->mchans_count; i++)
-		mbox_free_channel(sba->mchans[i]);
+fail_free_mchan:
+	mbox_free_channel(sba->mchan);
 	return ret;
 }
 
 static int sba_remove(struct platform_device *pdev)
 {
-	int i;
 	struct sba_device *sba = platform_get_drvdata(pdev);
 
 	dma_async_device_unregister(&sba->dma_dev);
@@ -1803,8 +1761,7 @@ static int sba_remove(struct platform_device *pdev)
 
 	sba_freeup_channel_resources(sba);
 
-	for (i = 0; i < sba->mchans_count; i++)
-		mbox_free_channel(sba->mchans[i]);
+	mbox_free_channel(sba->mchan);
 
 	return 0;
 }

drivers/dma/coh901318.c

@@ -1319,8 +1319,8 @@ static void coh901318_list_print(struct coh901318_chan *cohc,
 	int i = 0;
 
 	while (l) {
-		dev_vdbg(COHC_2_DEV(cohc), "i %d, lli %p, ctrl 0x%x, src 0x%pad"
-			 ", dst 0x%pad, link 0x%pad virt_link_addr 0x%p\n",
+		dev_vdbg(COHC_2_DEV(cohc), "i %d, lli %p, ctrl 0x%x, src %pad"
+			 ", dst %pad, link %pad virt_link_addr 0x%p\n",
 			 i, l, l->control, &l->src_addr, &l->dst_addr,
 			 &l->link_addr, l->virt_link_addr);
 		i++;
@@ -2231,7 +2231,7 @@ coh901318_prep_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 	spin_lock_irqsave(&cohc->lock, flg);
 
 	dev_vdbg(COHC_2_DEV(cohc),
-		 "[%s] channel %d src 0x%pad dest 0x%pad size %zu\n",
+		 "[%s] channel %d src %pad dest %pad size %zu\n",
 		 __func__, cohc->id, &src, &dest, size);
 
 	if (flags & DMA_PREP_INTERRUPT)

drivers/dma/dma-axi-dmac.c

@@ -72,6 +72,9 @@
 
 #define AXI_DMAC_FLAG_CYCLIC		BIT(0)
 
+/* The maximum ID allocated by the hardware is 31 */
+#define AXI_DMAC_SG_UNUSED 32U
+
 struct axi_dmac_sg {
 	dma_addr_t src_addr;
 	dma_addr_t dest_addr;
@@ -80,6 +83,7 @@ struct axi_dmac_sg {
 	unsigned int dest_stride;
 	unsigned int src_stride;
 	unsigned int id;
+	bool schedule_when_free;
 };
 
 struct axi_dmac_desc {
@@ -200,11 +204,21 @@ static void axi_dmac_start_transfer(struct axi_dmac_chan *chan)
 	}
 	sg = &desc->sg[desc->num_submitted];
 
+	/* Already queued in cyclic mode. Wait for it to finish */
+	if (sg->id != AXI_DMAC_SG_UNUSED) {
+		sg->schedule_when_free = true;
+		return;
+	}
+
 	desc->num_submitted++;
-	if (desc->num_submitted == desc->num_sgs)
-		chan->next_desc = NULL;
+	if (desc->num_submitted == desc->num_sgs) {
+		if (desc->cyclic)
+			desc->num_submitted = 0; /* Start again */
 		else
+			chan->next_desc = NULL;
+	} else {
 		chan->next_desc = desc;
+	}
 
 	sg->id = axi_dmac_read(dmac, AXI_DMAC_REG_TRANSFER_ID);
 
@@ -220,9 +234,11 @@ static void axi_dmac_start_transfer(struct axi_dmac_chan *chan)
 
 	/*
 	 * If the hardware supports cyclic transfers and there is no callback to
-	 * call, enable hw cyclic mode to avoid unnecessary interrupts.
+	 * call and only a single segment, enable hw cyclic mode to avoid
+	 * unnecessary interrupts.
 	 */
-	if (chan->hw_cyclic && desc->cyclic && !desc->vdesc.tx.callback)
+	if (chan->hw_cyclic && desc->cyclic && !desc->vdesc.tx.callback &&
+		desc->num_sgs == 1)
 		flags |= AXI_DMAC_FLAG_CYCLIC;
 
 	axi_dmac_write(dmac, AXI_DMAC_REG_X_LENGTH, sg->x_len - 1);
@@ -237,37 +253,52 @@ static struct axi_dmac_desc *axi_dmac_active_desc(struct axi_dmac_chan *chan)
 		struct axi_dmac_desc, vdesc.node);
 }
 
-static void axi_dmac_transfer_done(struct axi_dmac_chan *chan,
+static bool axi_dmac_transfer_done(struct axi_dmac_chan *chan,
 	unsigned int completed_transfers)
 {
 	struct axi_dmac_desc *active;
 	struct axi_dmac_sg *sg;
+	bool start_next = false;
 
 	active = axi_dmac_active_desc(chan);
 	if (!active)
-		return;
+		return false;
 
-	if (active->cyclic) {
-		vchan_cyclic_callback(&active->vdesc);
-	} else {
 	do {
 		sg = &active->sg[active->num_completed];
+		if (sg->id == AXI_DMAC_SG_UNUSED) /* Not yet submitted */
+			break;
 		if (!(BIT(sg->id) & completed_transfers))
 			break;
 		active->num_completed++;
+		sg->id = AXI_DMAC_SG_UNUSED;
+		if (sg->schedule_when_free) {
+			sg->schedule_when_free = false;
+			start_next = true;
+		}
+
+		if (active->cyclic)
+			vchan_cyclic_callback(&active->vdesc);
+
 		if (active->num_completed == active->num_sgs) {
+			if (active->cyclic) {
+				active->num_completed = 0; /* wrap around */
+			} else {
 				list_del(&active->vdesc.node);
 				vchan_cookie_complete(&active->vdesc);
 				active = axi_dmac_active_desc(chan);
 			}
-		} while (active);
 		}
+	} while (active);
+
+	return start_next;
 }
 
 static irqreturn_t axi_dmac_interrupt_handler(int irq, void *devid)
 {
 	struct axi_dmac *dmac = devid;
 	unsigned int pending;
+	bool start_next = false;
 
 	pending = axi_dmac_read(dmac, AXI_DMAC_REG_IRQ_PENDING);
 	if (!pending)
@@ -281,10 +312,10 @@ static irqreturn_t axi_dmac_interrupt_handler(int irq, void *devid)
 		unsigned int completed;
 
 		completed = axi_dmac_read(dmac, AXI_DMAC_REG_TRANSFER_DONE);
-		axi_dmac_transfer_done(&dmac->chan, completed);
+		start_next = axi_dmac_transfer_done(&dmac->chan, completed);
 	}
 	/* Space has become available in the descriptor queue */
-	if (pending & AXI_DMAC_IRQ_SOT)
+	if ((pending & AXI_DMAC_IRQ_SOT) || start_next)
 		axi_dmac_start_transfer(&dmac->chan);
 	spin_unlock(&dmac->chan.vchan.lock);
 
@@ -334,12 +365,16 @@ static void axi_dmac_issue_pending(struct dma_chan *c)
 static struct axi_dmac_desc *axi_dmac_alloc_desc(unsigned int num_sgs)
 {
 	struct axi_dmac_desc *desc;
+	unsigned int i;
 
 	desc = kzalloc(sizeof(struct axi_dmac_desc) +
 		sizeof(struct axi_dmac_sg) * num_sgs, GFP_NOWAIT);
 	if (!desc)
 		return NULL;
 
+	for (i = 0; i < num_sgs; i++)
+		desc->sg[i].id = AXI_DMAC_SG_UNUSED;
+
 	desc->num_sgs = num_sgs;
 
 	return desc;

drivers/dma/dmatest.c

@@ -702,6 +702,7 @@ static int dmatest_func(void *data)
 			 * free it this time?" dancing.  For now, just
 			 * leave it dangling.
 			 */
+			WARN(1, "dmatest: Kernel stack may be corrupted!!\n");
 			dmaengine_unmap_put(um);
 			result("test timed out", total_tests, src_off, dst_off,
 			       len, 0);

drivers/dma/edma.c

@@ -891,6 +891,10 @@ static int edma_slave_config(struct dma_chan *chan,
 	    cfg->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES)
 		return -EINVAL;
 
+	if (cfg->src_maxburst > chan->device->max_burst ||
+	    cfg->dst_maxburst > chan->device->max_burst)
+		return -EINVAL;
+
 	memcpy(&echan->cfg, cfg, sizeof(echan->cfg));
 
 	return 0;
@@ -1868,6 +1872,7 @@ static void edma_dma_init(struct edma_cc *ecc, bool legacy_mode)
 	s_ddev->dst_addr_widths = EDMA_DMA_BUSWIDTHS;
 	s_ddev->directions |= (BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV));
 	s_ddev->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
+	s_ddev->max_burst = SZ_32K - 1; /* CIDX: 16bit signed */
 
 	s_ddev->dev = ecc->dev;
 	INIT_LIST_HEAD(&s_ddev->channels);

drivers/dma/img-mdc-dma.c

@@ -23,6 +23,7 @@
 #include <linux/of_device.h>
 #include <linux/of_dma.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
@@ -730,14 +731,23 @@ static int mdc_slave_config(struct dma_chan *chan,
 	return 0;
 }
 
+static int mdc_alloc_chan_resources(struct dma_chan *chan)
+{
+	struct mdc_chan *mchan = to_mdc_chan(chan);
+	struct device *dev = mdma2dev(mchan->mdma);
+
+	return pm_runtime_get_sync(dev);
+}
+
 static void mdc_free_chan_resources(struct dma_chan *chan)
 {
 	struct mdc_chan *mchan = to_mdc_chan(chan);
 	struct mdc_dma *mdma = mchan->mdma;
+	struct device *dev = mdma2dev(mdma);
 
 	mdc_terminate_all(chan);
-
 	mdma->soc->disable_chan(mchan);
+	pm_runtime_put(dev);
 }
 
 static irqreturn_t mdc_chan_irq(int irq, void *dev_id)
@@ -854,6 +864,22 @@ static const struct of_device_id mdc_dma_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, mdc_dma_of_match);
 
+static int img_mdc_runtime_suspend(struct device *dev)
+{
+	struct mdc_dma *mdma = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(mdma->clk);
+
+	return 0;
+}
+
+static int img_mdc_runtime_resume(struct device *dev)
+{
+	struct mdc_dma *mdma = dev_get_drvdata(dev);
+
+	return clk_prepare_enable(mdma->clk);
+}
+
 static int mdc_dma_probe(struct platform_device *pdev)
 {
 	struct mdc_dma *mdma;
@@ -883,10 +909,6 @@ static int mdc_dma_probe(struct platform_device *pdev)
 	if (IS_ERR(mdma->clk))
 		return PTR_ERR(mdma->clk);
 
-	ret = clk_prepare_enable(mdma->clk);
-	if (ret)
-		return ret;
-
 	dma_cap_zero(mdma->dma_dev.cap_mask);
 	dma_cap_set(DMA_SLAVE, mdma->dma_dev.cap_mask);
 	dma_cap_set(DMA_PRIVATE, mdma->dma_dev.cap_mask);
@@ -919,12 +941,13 @@ static int mdc_dma_probe(struct platform_device *pdev)
 				   "img,max-burst-multiplier",
 				   &mdma->max_burst_mult);
 	if (ret)
-		goto disable_clk;
+		return ret;
 
 	mdma->dma_dev.dev = &pdev->dev;
 	mdma->dma_dev.device_prep_slave_sg = mdc_prep_slave_sg;
 	mdma->dma_dev.device_prep_dma_cyclic = mdc_prep_dma_cyclic;
 	mdma->dma_dev.device_prep_dma_memcpy = mdc_prep_dma_memcpy;
+	mdma->dma_dev.device_alloc_chan_resources = mdc_alloc_chan_resources;
 	mdma->dma_dev.device_free_chan_resources = mdc_free_chan_resources;
 	mdma->dma_dev.device_tx_status = mdc_tx_status;
 	mdma->dma_dev.device_issue_pending = mdc_issue_pending;
@@ -945,15 +968,14 @@ static int mdc_dma_probe(struct platform_device *pdev)
 		mchan->mdma = mdma;
 		mchan->chan_nr = i;
 		mchan->irq = platform_get_irq(pdev, i);
-		if (mchan->irq < 0) {
-			ret = mchan->irq;
-			goto disable_clk;
-		}
+		if (mchan->irq < 0)
+			return mchan->irq;
+
 		ret = devm_request_irq(&pdev->dev, mchan->irq, mdc_chan_irq,
 				       IRQ_TYPE_LEVEL_HIGH,
 				       dev_name(&pdev->dev), mchan);
 		if (ret < 0)
-			goto disable_clk;
+			return ret;
 
 		mchan->vc.desc_free = mdc_desc_free;
 		vchan_init(&mchan->vc, &mdma->dma_dev);
@@ -962,14 +984,19 @@ static int mdc_dma_probe(struct platform_device *pdev)
 	mdma->desc_pool = dmam_pool_create(dev_name(&pdev->dev), &pdev->dev,
 					   sizeof(struct mdc_hw_list_desc),
 					   4, 0);
-	if (!mdma->desc_pool) {
-		ret = -ENOMEM;
-		goto disable_clk;
+	if (!mdma->desc_pool)
+		return -ENOMEM;
+
+	pm_runtime_enable(&pdev->dev);
+	if (!pm_runtime_enabled(&pdev->dev)) {
+		ret = img_mdc_runtime_resume(&pdev->dev);
+		if (ret)
+			return ret;
 	}
 
 	ret = dma_async_device_register(&mdma->dma_dev);
 	if (ret)
-		goto disable_clk;
+		goto suspend;
 
 	ret = of_dma_controller_register(pdev->dev.of_node, mdc_of_xlate, mdma);
 	if (ret)
@@ -982,8 +1009,10 @@ static int mdc_dma_probe(struct platform_device *pdev)
 
 unregister:
 	dma_async_device_unregister(&mdma->dma_dev);
-disable_clk:
-	clk_disable_unprepare(mdma->clk);
+suspend:
+	if (!pm_runtime_enabled(&pdev->dev))
+		img_mdc_runtime_suspend(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
 	return ret;
 }
 
@@ -1004,14 +1033,47 @@ static int mdc_dma_remove(struct platform_device *pdev)
 		tasklet_kill(&mchan->vc.task);
 	}
 
-	clk_disable_unprepare(mdma->clk);
+	pm_runtime_disable(&pdev->dev);
+	if (!pm_runtime_status_suspended(&pdev->dev))
+		img_mdc_runtime_suspend(&pdev->dev);
 
 	return 0;
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int img_mdc_suspend_late(struct device *dev)
+{
+	struct mdc_dma *mdma = dev_get_drvdata(dev);
+	int i;
+
+	/* Check that all channels are idle */
+	for (i = 0; i < mdma->nr_channels; i++) {
+		struct mdc_chan *mchan = &mdma->channels[i];
+
+		if (unlikely(mchan->desc))
+			return -EBUSY;
+	}
+
+	return pm_runtime_force_suspend(dev);
+}
+
+static int img_mdc_resume_early(struct device *dev)
+{
+	return pm_runtime_force_resume(dev);
+}
+#endif /* CONFIG_PM_SLEEP */
+
+static const struct dev_pm_ops img_mdc_pm_ops = {
+	SET_RUNTIME_PM_OPS(img_mdc_runtime_suspend,
+			   img_mdc_runtime_resume, NULL)
+	SET_LATE_SYSTEM_SLEEP_PM_OPS(img_mdc_suspend_late,
+				     img_mdc_resume_early)
+};
+
 static struct platform_driver mdc_dma_driver = {
 	.driver = {
 		.name = "img-mdc-dma",
+		.pm = &img_mdc_pm_ops,
 		.of_match_table = of_match_ptr(mdc_dma_of_match),
 	},
 	.probe = mdc_dma_probe,

drivers/dma/imx-dma.c

@@ -364,9 +364,9 @@ static void imxdma_disable_hw(struct imxdma_channel *imxdmac)
 	local_irq_restore(flags);
 }
 
-static void imxdma_watchdog(unsigned long data)
+static void imxdma_watchdog(struct timer_list *t)
 {
-	struct imxdma_channel *imxdmac = (struct imxdma_channel *)data;
+	struct imxdma_channel *imxdmac = from_timer(imxdmac, t, watchdog);
 	struct imxdma_engine *imxdma = imxdmac->imxdma;
 	int channel = imxdmac->channel;
 
@@ -1153,9 +1153,7 @@ static int __init imxdma_probe(struct platform_device *pdev)
 			}
 
 			imxdmac->irq = irq + i;
-			init_timer(&imxdmac->watchdog);
-			imxdmac->watchdog.function = &imxdma_watchdog;
-			imxdmac->watchdog.data = (unsigned long)imxdmac;
+			timer_setup(&imxdmac->watchdog, imxdma_watchdog, 0);
 		}
 
 		imxdmac->imxdma = imxdma;

drivers/dma/imx-sdma.c

@@ -178,6 +178,14 @@
 #define SDMA_WATERMARK_LEVEL_HWE	BIT(29)
 #define SDMA_WATERMARK_LEVEL_CONT	BIT(31)
 
+#define SDMA_DMA_BUSWIDTHS	(BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
+				 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
+				 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES))
+
+#define SDMA_DMA_DIRECTIONS	(BIT(DMA_DEV_TO_MEM) | \
+				 BIT(DMA_MEM_TO_DEV) | \
+				 BIT(DMA_DEV_TO_DEV))
+
 /*
  * Mode/Count of data node descriptors - IPCv2
  */
@@ -1851,9 +1859,9 @@ static int sdma_probe(struct platform_device *pdev)
 	sdma->dma_device.device_prep_dma_cyclic = sdma_prep_dma_cyclic;
 	sdma->dma_device.device_config = sdma_config;
 	sdma->dma_device.device_terminate_all = sdma_disable_channel_with_delay;
-	sdma->dma_device.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
-	sdma->dma_device.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
-	sdma->dma_device.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
+	sdma->dma_device.src_addr_widths = SDMA_DMA_BUSWIDTHS;
+	sdma->dma_device.dst_addr_widths = SDMA_DMA_BUSWIDTHS;
+	sdma->dma_device.directions = SDMA_DMA_DIRECTIONS;
 	sdma->dma_device.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
 	sdma->dma_device.device_issue_pending = sdma_issue_pending;
 	sdma->dma_device.dev->dma_parms = &sdma->dma_parms;

drivers/dma/ioat/dma.c

@@ -474,7 +474,7 @@ int ioat_check_space_lock(struct ioatdma_chan *ioat_chan, int num_descs)
 	if (time_is_before_jiffies(ioat_chan->timer.expires)
 	    && timer_pending(&ioat_chan->timer)) {
 		mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
-		ioat_timer_event((unsigned long)ioat_chan);
+		ioat_timer_event(&ioat_chan->timer);
 	}
 
 	return -ENOMEM;
@@ -862,9 +862,9 @@ static void check_active(struct ioatdma_chan *ioat_chan)
 		mod_timer(&ioat_chan->timer, jiffies + IDLE_TIMEOUT);
 }
 
-void ioat_timer_event(unsigned long data)
+void ioat_timer_event(struct timer_list *t)
 {
-	struct ioatdma_chan *ioat_chan = to_ioat_chan((void *)data);
+	struct ioatdma_chan *ioat_chan = from_timer(ioat_chan, t, timer);
 	dma_addr_t phys_complete;
 	u64 status;
 

drivers/dma/ioat/dma.h

@@ -406,10 +406,9 @@ enum dma_status
 ioat_tx_status(struct dma_chan *c, dma_cookie_t cookie,
 		struct dma_tx_state *txstate);
 void ioat_cleanup_event(unsigned long data);
-void ioat_timer_event(unsigned long data);
+void ioat_timer_event(struct timer_list *t);
 int ioat_check_space_lock(struct ioatdma_chan *ioat_chan, int num_descs);
 void ioat_issue_pending(struct dma_chan *chan);
-void ioat_timer_event(unsigned long data);
 
 /* IOAT Init functions */
 bool is_bwd_ioat(struct pci_dev *pdev);

drivers/dma/ioat/init.c

@@ -760,7 +760,7 @@ ioat_init_channel(struct ioatdma_device *ioat_dma,
 	dma_cookie_init(&ioat_chan->dma_chan);
 	list_add_tail(&ioat_chan->dma_chan.device_node, &dma->channels);
 	ioat_dma->idx[idx] = ioat_chan;
-	setup_timer(&ioat_chan->timer, ioat_timer_event, data);
+	timer_setup(&ioat_chan->timer, ioat_timer_event, 0);
 	tasklet_init(&ioat_chan->cleanup_task, ioat_cleanup_event, data);
 }
 

drivers/dma/nbpfaxi.c

@@ -1286,7 +1286,6 @@ MODULE_DEVICE_TABLE(of, nbpf_match);
 static int nbpf_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
-	const struct of_device_id *of_id = of_match_device(nbpf_match, dev);
 	struct device_node *np = dev->of_node;
 	struct nbpf_device *nbpf;
 	struct dma_device *dma_dev;
@@ -1300,10 +1299,10 @@ static int nbpf_probe(struct platform_device *pdev)
 	BUILD_BUG_ON(sizeof(struct nbpf_desc_page) > PAGE_SIZE);
 
 	/* DT only */
-	if (!np || !of_id || !of_id->data)
+	if (!np)
 		return -ENODEV;
 
-	cfg = of_id->data;
+	cfg = of_device_get_match_data(dev);
 	num_channels = cfg->num_channels;
 
 	nbpf = devm_kzalloc(dev, sizeof(*nbpf) + num_channels *

drivers/dma/omap-dma.c

@@ -1288,6 +1288,10 @@ static int omap_dma_slave_config(struct dma_chan *chan, struct dma_slave_config
 	    cfg->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES)
 		return -EINVAL;
 
+	if (cfg->src_maxburst > chan->device->max_burst ||
+	    cfg->dst_maxburst > chan->device->max_burst)
+		return -EINVAL;
+
 	memcpy(&c->cfg, cfg, sizeof(c->cfg));
 
 	return 0;
@@ -1482,6 +1486,7 @@ static int omap_dma_probe(struct platform_device *pdev)
 	od->ddev.dst_addr_widths = OMAP_DMA_BUSWIDTHS;
 	od->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
 	od->ddev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
+	od->ddev.max_burst = SZ_16M - 1; /* CCEN: 24bit unsigned */
 	od->ddev.dev = &pdev->dev;
 	INIT_LIST_HEAD(&od->ddev.channels);
 	spin_lock_init(&od->lock);

drivers/dma/pch_dma.c

@@ -123,7 +123,7 @@ struct pch_dma_chan {
 struct pch_dma {
 	struct dma_device	dma;
 	void __iomem *membase;
-	struct pci_pool		*pool;
+	struct dma_pool		*pool;
 	struct pch_dma_regs	regs;
 	struct pch_dma_desc_regs ch_regs[MAX_CHAN_NR];
 	struct pch_dma_chan	channels[MAX_CHAN_NR];
@@ -437,7 +437,7 @@ static struct pch_dma_desc *pdc_alloc_desc(struct dma_chan *chan, gfp_t flags)
 	struct pch_dma *pd = to_pd(chan->device);
 	dma_addr_t addr;
 
-	desc = pci_pool_zalloc(pd->pool, flags, &addr);
+	desc = dma_pool_zalloc(pd->pool, flags, &addr);
 	if (desc) {
 		INIT_LIST_HEAD(&desc->tx_list);
 		dma_async_tx_descriptor_init(&desc->txd, chan);
@@ -549,7 +549,7 @@ static void pd_free_chan_resources(struct dma_chan *chan)
 	spin_unlock_irq(&pd_chan->lock);
 
 	list_for_each_entry_safe(desc, _d, &tmp_list, desc_node)
-		pci_pool_free(pd->pool, desc, desc->txd.phys);
+		dma_pool_free(pd->pool, desc, desc->txd.phys);
 
 	pdc_enable_irq(chan, 0);
 }
@@ -880,7 +880,7 @@ static int pch_dma_probe(struct pci_dev *pdev,
 		goto err_iounmap;
 	}
 
-	pd->pool = pci_pool_create("pch_dma_desc_pool", pdev,
+	pd->pool = dma_pool_create("pch_dma_desc_pool", &pdev->dev,
 				   sizeof(struct pch_dma_desc), 4, 0);
 	if (!pd->pool) {
 		dev_err(&pdev->dev, "Failed to alloc DMA descriptors\n");
@@ -931,7 +931,7 @@ static int pch_dma_probe(struct pci_dev *pdev,
 	return 0;
 
 err_free_pool:
-	pci_pool_destroy(pd->pool);
+	dma_pool_destroy(pd->pool);
 err_free_irq:
 	free_irq(pdev->irq, pd);
 err_iounmap:
@@ -963,7 +963,7 @@ static void pch_dma_remove(struct pci_dev *pdev)
 			tasklet_kill(&pd_chan->tasklet);
 		}
 
-		pci_pool_destroy(pd->pool);
+		dma_pool_destroy(pd->pool);
 		pci_iounmap(pdev, pd->membase);
 		pci_release_regions(pdev);
 		pci_disable_device(pdev);

drivers/dma/pl330.c

@@ -2390,7 +2390,8 @@ static inline void _init_desc(struct dma_pl330_desc *desc)
 }
 
 /* Returns the number of descriptors added to the DMAC pool */
-static int add_desc(struct pl330_dmac *pl330, gfp_t flg, int count)
+static int add_desc(struct list_head *pool, spinlock_t *lock,
+		    gfp_t flg, int count)
 {
 	struct dma_pl330_desc *desc;
 	unsigned long flags;
@@ -2400,27 +2401,28 @@ static int add_desc(struct pl330_dmac *pl330, gfp_t flg, int count)
 	if (!desc)
 		return 0;
 
-	spin_lock_irqsave(&pl330->pool_lock, flags);
+	spin_lock_irqsave(lock, flags);
 
 	for (i = 0; i < count; i++) {
 		_init_desc(&desc[i]);
-		list_add_tail(&desc[i].node, &pl330->desc_pool);
+		list_add_tail(&desc[i].node, pool);
 	}
 
-	spin_unlock_irqrestore(&pl330->pool_lock, flags);
+	spin_unlock_irqrestore(lock, flags);
 
 	return count;
 }
 
-static struct dma_pl330_desc *pluck_desc(struct pl330_dmac *pl330)
+static struct dma_pl330_desc *pluck_desc(struct list_head *pool,
+					 spinlock_t *lock)
 {
 	struct dma_pl330_desc *desc = NULL;
 	unsigned long flags;
 
-	spin_lock_irqsave(&pl330->pool_lock, flags);
+	spin_lock_irqsave(lock, flags);
 
-	if (!list_empty(&pl330->desc_pool)) {
-		desc = list_entry(pl330->desc_pool.next,
+	if (!list_empty(pool)) {
+		desc = list_entry(pool->next,
 				struct dma_pl330_desc, node);
 
 		list_del_init(&desc->node);
@@ -2429,7 +2431,7 @@ static struct dma_pl330_desc *pluck_desc(struct pl330_dmac *pl330)
 		desc->txd.callback = NULL;
 	}
 
-	spin_unlock_irqrestore(&pl330->pool_lock, flags);
+	spin_unlock_irqrestore(lock, flags);
 
 	return desc;
 }
@@ -2441,20 +2443,18 @@ static struct dma_pl330_desc *pl330_get_desc(struct dma_pl330_chan *pch)
 	struct dma_pl330_desc *desc;
 
 	/* Pluck one desc from the pool of DMAC */
-	desc = pluck_desc(pl330);
+	desc = pluck_desc(&pl330->desc_pool, &pl330->pool_lock);
 
 	/* If the DMAC pool is empty, alloc new */
 	if (!desc) {
-		if (!add_desc(pl330, GFP_ATOMIC, 1))
-			return NULL;
+		DEFINE_SPINLOCK(lock);
+		LIST_HEAD(pool);
 
-		/* Try again */
-		desc = pluck_desc(pl330);
-		if (!desc) {
-			dev_err(pch->dmac->ddma.dev,
-				"%s:%d ALERT!\n", __func__, __LINE__);
+		if (!add_desc(&pool, &lock, GFP_ATOMIC, 1))
 			return NULL;
-		}
+
+		desc = pluck_desc(&pool, &lock);
+		WARN_ON(!desc || !list_empty(&pool));
 	}
 
 	/* Initialize the descriptor */
@@ -2868,7 +2868,8 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
 	spin_lock_init(&pl330->pool_lock);
 
 	/* Create a descriptor pool of default size */
-	if (!add_desc(pl330, GFP_KERNEL, NR_DEFAULT_DESC))
+	if (!add_desc(&pl330->desc_pool, &pl330->pool_lock,
+		      GFP_KERNEL, NR_DEFAULT_DESC))
 		dev_warn(&adev->dev, "unable to allocate desc\n");
 
 	INIT_LIST_HEAD(&pd->channels);

drivers/dma/qcom/bam_dma.c

@@ -46,6 +46,7 @@
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/of_dma.h>
+#include <linux/circ_buf.h>
 #include <linux/clk.h>
 #include <linux/dmaengine.h>
 #include <linux/pm_runtime.h>
@@ -78,6 +79,8 @@ struct bam_async_desc {
 
 	struct bam_desc_hw *curr_desc;
 
+	/* list node for the desc in the bam_chan list of descriptors */
+	struct list_head desc_node;
 	enum dma_transfer_direction dir;
 	size_t length;
 	struct bam_desc_hw desc[0];
@@ -347,6 +350,8 @@ static const struct reg_offset_data bam_v1_7_reg_info[] = {
 #define BAM_DESC_FIFO_SIZE	SZ_32K
 #define MAX_DESCRIPTORS (BAM_DESC_FIFO_SIZE / sizeof(struct bam_desc_hw) - 1)
 #define BAM_FIFO_SIZE	(SZ_32K - 8)
+#define IS_BUSY(chan)	(CIRC_SPACE(bchan->tail, bchan->head,\
+			 MAX_DESCRIPTORS + 1) == 0)
 
 struct bam_chan {
 	struct virt_dma_chan vc;
@@ -356,8 +361,6 @@ struct bam_chan {
 	/* configuration from device tree */
 	u32 id;
 
-	struct bam_async_desc *curr_txd;	/* current running dma */
-
 	/* runtime configuration */
 	struct dma_slave_config slave;
 
@@ -372,6 +375,8 @@ struct bam_chan {
 	unsigned int initialized;	/* is the channel hw initialized? */
 	unsigned int paused;		/* is the channel paused? */
 	unsigned int reconfigure;	/* new slave config? */
+	/* list of descriptors currently processed */
+	struct list_head desc_list;
 
 	struct list_head node;
 };
@@ -539,7 +544,7 @@ static void bam_free_chan(struct dma_chan *chan)
 
 	vchan_free_chan_resources(to_virt_chan(chan));
 
-	if (bchan->curr_txd) {
+	if (!list_empty(&bchan->desc_list)) {
 		dev_err(bchan->bdev->dev, "Cannot free busy channel\n");
 		goto err;
 	}
@@ -632,8 +637,6 @@ static struct dma_async_tx_descriptor *bam_prep_slave_sg(struct dma_chan *chan,
 
 	if (flags & DMA_PREP_INTERRUPT)
 		async_desc->flags |= DESC_FLAG_EOT;
-	else
-		async_desc->flags |= DESC_FLAG_INT;
 
 	async_desc->num_desc = num_alloc;
 	async_desc->curr_desc = async_desc->desc;
@@ -684,14 +687,16 @@ static struct dma_async_tx_descriptor *bam_prep_slave_sg(struct dma_chan *chan,
 static int bam_dma_terminate_all(struct dma_chan *chan)
 {
 	struct bam_chan *bchan = to_bam_chan(chan);
+	struct bam_async_desc *async_desc, *tmp;
 	unsigned long flag;
 	LIST_HEAD(head);
 
 	/* remove all transactions, including active transaction */
 	spin_lock_irqsave(&bchan->vc.lock, flag);
-	if (bchan->curr_txd) {
-		list_add(&bchan->curr_txd->vd.node, &bchan->vc.desc_issued);
-		bchan->curr_txd = NULL;
+	list_for_each_entry_safe(async_desc, tmp,
+				 &bchan->desc_list, desc_node) {
+		list_add(&async_desc->vd.node, &bchan->vc.desc_issued);
+		list_del(&async_desc->desc_node);
 	}
 
 	vchan_get_all_descriptors(&bchan->vc, &head);
@@ -763,9 +768,9 @@ static int bam_resume(struct dma_chan *chan)
  */
 static u32 process_channel_irqs(struct bam_device *bdev)
 {
-	u32 i, srcs, pipe_stts;
+	u32 i, srcs, pipe_stts, offset, avail;
 	unsigned long flags;
-	struct bam_async_desc *async_desc;
+	struct bam_async_desc *async_desc, *tmp;
 
 	srcs = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_EE));
 
@@ -785,28 +790,41 @@ static u32 process_channel_irqs(struct bam_device *bdev)
 		writel_relaxed(pipe_stts, bam_addr(bdev, i, BAM_P_IRQ_CLR));
 
 		spin_lock_irqsave(&bchan->vc.lock, flags);
-		async_desc = bchan->curr_txd;
 
-		if (async_desc) {
-			async_desc->num_desc -= async_desc->xfer_len;
-			async_desc->curr_desc += async_desc->xfer_len;
-			bchan->curr_txd = NULL;
+		offset = readl_relaxed(bam_addr(bdev, i, BAM_P_SW_OFSTS)) &
+				       P_SW_OFSTS_MASK;
+		offset /= sizeof(struct bam_desc_hw);
+
+		/* Number of bytes available to read */
+		avail = CIRC_CNT(offset, bchan->head, MAX_DESCRIPTORS + 1);
+
+		list_for_each_entry_safe(async_desc, tmp,
+					 &bchan->desc_list, desc_node) {
+			/* Not enough data to read */
+			if (avail < async_desc->xfer_len)
+				break;
 
 			/* manage FIFO */
 			bchan->head += async_desc->xfer_len;
 			bchan->head %= MAX_DESCRIPTORS;
 
+			async_desc->num_desc -= async_desc->xfer_len;
+			async_desc->curr_desc += async_desc->xfer_len;
+			avail -= async_desc->xfer_len;
+
 			/*
 			 * if complete, process cookie. Otherwise
 			 * push back to front of desc_issued so that
 			 * it gets restarted by the tasklet
 			 */
-			if (!async_desc->num_desc)
+			if (!async_desc->num_desc) {
 				vchan_cookie_complete(&async_desc->vd);
-			else
+			} else {
 				list_add(&async_desc->vd.node,
 					 &bchan->vc.desc_issued);
 			}
+			list_del(&async_desc->desc_node);
+		}
 
 		spin_unlock_irqrestore(&bchan->vc.lock, flags);
 	}
@@ -867,6 +885,7 @@ static enum dma_status bam_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
 		struct dma_tx_state *txstate)
 {
 	struct bam_chan *bchan = to_bam_chan(chan);
+	struct bam_async_desc *async_desc;
 	struct virt_dma_desc *vd;
 	int ret;
 	size_t residue = 0;
@@ -882,11 +901,17 @@ static enum dma_status bam_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
 
 	spin_lock_irqsave(&bchan->vc.lock, flags);
 	vd = vchan_find_desc(&bchan->vc, cookie);
-	if (vd)
+	if (vd) {
 		residue = container_of(vd, struct bam_async_desc, vd)->length;
-	else if (bchan->curr_txd && bchan->curr_txd->vd.tx.cookie == cookie)
-		for (i = 0; i < bchan->curr_txd->num_desc; i++)
-			residue += bchan->curr_txd->curr_desc[i].size;
+	} else {
+		list_for_each_entry(async_desc, &bchan->desc_list, desc_node) {
+			if (async_desc->vd.tx.cookie != cookie)
+				continue;
+
+			for (i = 0; i < async_desc->num_desc; i++)
+				residue += async_desc->curr_desc[i].size;
+		}
+	}
 
 	spin_unlock_irqrestore(&bchan->vc.lock, flags);
 
@@ -927,26 +952,28 @@ static void bam_start_dma(struct bam_chan *bchan)
 {
 	struct virt_dma_desc *vd = vchan_next_desc(&bchan->vc);
 	struct bam_device *bdev = bchan->bdev;
-	struct bam_async_desc *async_desc;
+	struct bam_async_desc *async_desc = NULL;
 	struct bam_desc_hw *desc;
 	struct bam_desc_hw *fifo = PTR_ALIGN(bchan->fifo_virt,
 					sizeof(struct bam_desc_hw));
 	int ret;
+	unsigned int avail;
+	struct dmaengine_desc_callback cb;
 
 	lockdep_assert_held(&bchan->vc.lock);
 
 	if (!vd)
 		return;
 
-	list_del(&vd->node);
-
-	async_desc = container_of(vd, struct bam_async_desc, vd);
-	bchan->curr_txd = async_desc;
-
 	ret = pm_runtime_get_sync(bdev->dev);
 	if (ret < 0)
 		return;
 
+	while (vd && !IS_BUSY(bchan)) {
+		list_del(&vd->node);
+
+		async_desc = container_of(vd, struct bam_async_desc, vd);
+
 		/* on first use, initialize the channel hardware */
 		if (!bchan->initialized)
 			bam_chan_init_hw(bchan, async_desc->dir);
@@ -955,10 +982,12 @@ static void bam_start_dma(struct bam_chan *bchan)
 		if (bchan->reconfigure)
 			bam_apply_new_config(bchan, async_desc->dir);
 
-	desc = bchan->curr_txd->curr_desc;
+		desc = async_desc->curr_desc;
+		avail = CIRC_SPACE(bchan->tail, bchan->head,
+				   MAX_DESCRIPTORS + 1);
 
-	if (async_desc->num_desc > MAX_DESCRIPTORS)
-		async_desc->xfer_len = MAX_DESCRIPTORS;
+		if (async_desc->num_desc > avail)
+			async_desc->xfer_len = avail;
 		else
 			async_desc->xfer_len = async_desc->num_desc;
 
@@ -966,7 +995,22 @@ static void bam_start_dma(struct bam_chan *bchan)
 		if (async_desc->num_desc == async_desc->xfer_len)
 			desc[async_desc->xfer_len - 1].flags |=
 						cpu_to_le16(async_desc->flags);
-	else
+
+		vd = vchan_next_desc(&bchan->vc);
+
+		dmaengine_desc_get_callback(&async_desc->vd.tx, &cb);
+
+		/*
+		 * An interrupt is generated at this desc, if
+		 *  - FIFO is FULL.
+		 *  - No more descriptors to add.
+		 *  - If a callback completion was requested for this DESC,
+		 *     In this case, BAM will deliver the completion callback
+		 *     for this desc and continue processing the next desc.
+		 */
+		if (((avail <= async_desc->xfer_len) || !vd ||
+		     dmaengine_desc_callback_valid(&cb)) &&
+		    !(async_desc->flags & DESC_FLAG_EOT))
 			desc[async_desc->xfer_len - 1].flags |=
 				cpu_to_le16(DESC_FLAG_INT);
 
@@ -975,15 +1019,19 @@ static void bam_start_dma(struct bam_chan *bchan)
 
 			memcpy(&fifo[bchan->tail], desc,
 			       partial * sizeof(struct bam_desc_hw));
-		memcpy(fifo, &desc[partial], (async_desc->xfer_len - partial) *
+			memcpy(fifo, &desc[partial],
+			       (async_desc->xfer_len - partial) *
 				sizeof(struct bam_desc_hw));
 		} else {
 			memcpy(&fifo[bchan->tail], desc,
-			async_desc->xfer_len * sizeof(struct bam_desc_hw));
+			       async_desc->xfer_len *
+			       sizeof(struct bam_desc_hw));
 		}
 
 		bchan->tail += async_desc->xfer_len;
 		bchan->tail %= MAX_DESCRIPTORS;
+		list_add_tail(&async_desc->desc_node, &bchan->desc_list);
+	}
 
 	/* ensure descriptor writes and dma start not reordered */
 	wmb();
@@ -1012,7 +1060,7 @@ static void dma_tasklet(unsigned long data)
 		bchan = &bdev->channels[i];
 		spin_lock_irqsave(&bchan->vc.lock, flags);
 
-		if (!list_empty(&bchan->vc.desc_issued) && !bchan->curr_txd)
+		if (!list_empty(&bchan->vc.desc_issued) && !IS_BUSY(bchan))
 			bam_start_dma(bchan);
 		spin_unlock_irqrestore(&bchan->vc.lock, flags);
 	}
@@ -1033,7 +1081,7 @@ static void bam_issue_pending(struct dma_chan *chan)
 	spin_lock_irqsave(&bchan->vc.lock, flags);
 
 	/* if work pending and idle, start a transaction */
-	if (vchan_issue_pending(&bchan->vc) && !bchan->curr_txd)
+	if (vchan_issue_pending(&bchan->vc) && !IS_BUSY(bchan))
 		bam_start_dma(bchan);
 
 	spin_unlock_irqrestore(&bchan->vc.lock, flags);
@@ -1133,6 +1181,7 @@ static void bam_channel_init(struct bam_device *bdev, struct bam_chan *bchan,
 
 	vchan_init(&bchan->vc, &bdev->common);
 	bchan->vc.desc_free = bam_dma_free_desc;
+	INIT_LIST_HEAD(&bchan->desc_list);
 }
 
 static const struct of_device_id bam_of_match[] = {

drivers/dma/sa11x0-dma.c

@@ -823,6 +823,13 @@ static const struct sa11x0_dma_channel_desc chan_desc[] = {
 	CD(Ser4SSPRc, DDAR_RW),
 };
 
+static const struct dma_slave_map sa11x0_dma_map[] = {
+	{ "sa11x0-ir", "tx", "Ser2ICPTr" },
+	{ "sa11x0-ir", "rx", "Ser2ICPRc" },
+	{ "sa11x0-ssp", "tx", "Ser4SSPTr" },
+	{ "sa11x0-ssp", "rx", "Ser4SSPRc" },
+};
+
 static int sa11x0_dma_init_dmadev(struct dma_device *dmadev,
 	struct device *dev)
 {
@@ -909,6 +916,10 @@ static int sa11x0_dma_probe(struct platform_device *pdev)
 	spin_lock_init(&d->lock);
 	INIT_LIST_HEAD(&d->chan_pending);
 
+	d->slave.filter.fn = sa11x0_dma_filter_fn;
+	d->slave.filter.mapcnt = ARRAY_SIZE(sa11x0_dma_map);
+	d->slave.filter.map = sa11x0_dma_map;
+
 	d->base = ioremap(res->start, resource_size(res));
 	if (!d->base) {
 		ret = -ENOMEM;

drivers/dma/stm32-dmamux.c

+/*
+ *
+ * Copyright (C) STMicroelectronics SA 2017
+ * Author(s): M'boumba Cedric Madianga <cedric.madianga@gmail.com>
+ *            Pierre-Yves Mordret <pierre-yves.mordret@st.com>
+ *
+ * License terms: GPL V2.0.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * DMA Router driver for STM32 DMA MUX
+ *
+ * Based on TI DMA Crossbar driver
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of_dma.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#define STM32_DMAMUX_CCR(x)		(0x4 * (x))
+#define STM32_DMAMUX_MAX_DMA_REQUESTS	32
+#define STM32_DMAMUX_MAX_REQUESTS	255
+
+struct stm32_dmamux {
+	u32 master;
+	u32 request;
+	u32 chan_id;
+};
+
+struct stm32_dmamux_data {
+	struct dma_router dmarouter;
+	struct clk *clk;
+	struct reset_control *rst;
+	void __iomem *iomem;
+	u32 dma_requests; /* Number of DMA requests connected to DMAMUX */
+	u32 dmamux_requests; /* Number of DMA requests routed toward DMAs */
+	spinlock_t lock; /* Protects register access */
+	unsigned long *dma_inuse; /* Used DMA channel */
+	u32 dma_reqs[]; /* Number of DMA Request per DMA masters.
+			 *  [0] holds number of DMA Masters.
+			 *  To be kept at very end end of this structure
+			 */
+};
+
+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);
+}
+
+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);
+
+	stm32_dmamux_write(dmamux->iomem, STM32_DMAMUX_CCR(mux->chan_id), 0);
+	clear_bit(mux->chan_id, dmamux->dma_inuse);
+
+	if (!IS_ERR(dmamux->clk))
+		clk_disable(dmamux->clk);
+
+	spin_unlock_irqrestore(&dmamux->lock, flags);
+
+	dev_dbg(dev, "Unmapping DMAMUX(%u) to DMA%u(%u)\n",
+		mux->request, mux->master, mux->chan_id);
+
+	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;
+	u32 i, min, max;
+	int ret;
+	unsigned long flags;
+
+	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);
+	}
+
+	mux = kzalloc(sizeof(*mux), GFP_KERNEL);
+	if (!mux)
+		return ERR_PTR(-ENOMEM);
+
+	spin_lock_irqsave(&dmamux->lock, flags);
+	mux->chan_id = find_first_zero_bit(dmamux->dma_inuse,
+					   dmamux->dma_requests);
+	set_bit(mux->chan_id, dmamux->dma_inuse);
+	spin_unlock_irqrestore(&dmamux->lock, flags);
+
+	if (mux->chan_id == dmamux->dma_requests) {
+		dev_err(&pdev->dev, "Run out of free DMA requests\n");
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	/* Look for DMA Master */
+	for (i = 1, min = 0, max = dmamux->dma_reqs[i];
+	     i <= dmamux->dma_reqs[0];
+	     min += dmamux->dma_reqs[i], max += dmamux->dma_reqs[++i])
+		if (mux->chan_id < max)
+			break;
+	mux->master = i - 1;
+
+	/* The of_node_put() will be done in of_dma_router_xlate function */
+	dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", i - 1);
+	if (!dma_spec->np) {
+		dev_err(&pdev->dev, "can't get dma master\n");
+		ret = -EINVAL;
+		goto error;
+	}
+
+	/* 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(&pdev->dev, "clk_prep_enable issue: %d\n", ret);
+			goto error;
+		}
+	}
+	spin_unlock_irqrestore(&dmamux->lock, flags);
+
+	mux->request = dma_spec->args[0];
+
+	/*  craft DMA spec */
+	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] = mux->chan_id - min;
+	dma_spec->args_count = 4;
+
+	stm32_dmamux_write(dmamux->iomem, STM32_DMAMUX_CCR(mux->chan_id),
+			   mux->request);
+	dev_dbg(&pdev->dev, "Mapping DMAMUX(%u) to DMA%u(%u)\n",
+		mux->request, mux->master, mux->chan_id);
+
+	return mux;
+
+error:
+	clear_bit(mux->chan_id, dmamux->dma_inuse);
+	kfree(mux);
+	return ERR_PTR(ret);
+}
+
+static const struct of_device_id stm32_stm32dma_master_match[] = {
+	{ .compatible = "st,stm32-dma", },
+	{},
+};
+
+static int stm32_dmamux_probe(struct platform_device *pdev)
+{
+	struct device_node *node = pdev->dev.of_node;
+	const struct of_device_id *match;
+	struct device_node *dma_node;
+	struct stm32_dmamux_data *stm32_dmamux;
+	struct resource *res;
+	void __iomem *iomem;
+	int i, count, ret;
+	u32 dma_req;
+
+	if (!node)
+		return -ENODEV;
+
+	count = device_property_read_u32_array(&pdev->dev, "dma-masters",
+					       NULL, 0);
+	if (count < 0) {
+		dev_err(&pdev->dev, "Can't get DMA master(s) node\n");
+		return -ENODEV;
+	}
+
+	stm32_dmamux = devm_kzalloc(&pdev->dev, sizeof(*stm32_dmamux) +
+				    sizeof(u32) * (count + 1), GFP_KERNEL);
+	if (!stm32_dmamux)
+		return -ENOMEM;
+
+	dma_req = 0;
+	for (i = 1; i <= count; i++) {
+		dma_node = of_parse_phandle(node, "dma-masters", i - 1);
+
+		match = of_match_node(stm32_stm32dma_master_match, dma_node);
+		if (!match) {
+			dev_err(&pdev->dev, "DMA master is not supported\n");
+			of_node_put(dma_node);
+			return -EINVAL;
+		}
+
+		if (of_property_read_u32(dma_node, "dma-requests",
+					 &stm32_dmamux->dma_reqs[i])) {
+			dev_info(&pdev->dev,
+				 "Missing MUX output information, using %u.\n",
+				 STM32_DMAMUX_MAX_DMA_REQUESTS);
+			stm32_dmamux->dma_reqs[i] =
+				STM32_DMAMUX_MAX_DMA_REQUESTS;
+		}
+		dma_req += stm32_dmamux->dma_reqs[i];
+		of_node_put(dma_node);
+	}
+
+	if (dma_req > STM32_DMAMUX_MAX_DMA_REQUESTS) {
+		dev_err(&pdev->dev, "Too many DMA Master Requests to manage\n");
+		return -ENODEV;
+	}
+
+	stm32_dmamux->dma_requests = dma_req;
+	stm32_dmamux->dma_reqs[0] = count;
+	stm32_dmamux->dma_inuse = devm_kcalloc(&pdev->dev,
+					       BITS_TO_LONGS(dma_req),
+					       sizeof(unsigned long),
+					       GFP_KERNEL);
+	if (!stm32_dmamux->dma_inuse)
+		return -ENOMEM;
+
+	if (device_property_read_u32(&pdev->dev, "dma-requests",
+				     &stm32_dmamux->dmamux_requests)) {
+		stm32_dmamux->dmamux_requests = STM32_DMAMUX_MAX_REQUESTS;
+		dev_warn(&pdev->dev, "DMAMUX defaulting on %u requests\n",
+			 stm32_dmamux->dmamux_requests);
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENODEV;
+
+	iomem = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(iomem))
+		return PTR_ERR(iomem);
+
+	spin_lock_init(&stm32_dmamux->lock);
+
+	stm32_dmamux->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(stm32_dmamux->clk)) {
+		ret = PTR_ERR(stm32_dmamux->clk);
+		if (ret == -EPROBE_DEFER)
+			dev_info(&pdev->dev, "Missing controller clock\n");
+		return ret;
+	}
+
+	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 error: %d\n", ret);
+			return ret;
+		}
+	}
+
+	/* Reset the dmamux */
+	for (i = 0; i < stm32_dmamux->dma_requests; 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,stm32h7-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);
+
+MODULE_DESCRIPTION("DMA Router driver for STM32 DMA MUX");
+MODULE_AUTHOR("M'boumba Cedric Madianga <cedric.madianga@gmail.com>");
+MODULE_AUTHOR("Pierre-Yves Mordret <pierre-yves.mordret@st.com>");
+MODULE_LICENSE("GPL v2");