[PATCH v3 0/4] Add Actions Semi Owl family S900 DMA Controller support

[PATCH v3 0/4] Add Actions Semi Owl family S900 DMA Controller support

[Manivannan Sadhasivam]

This patchset adds DMA controller support for Actions Semi Owl family
S900 SoC. This driver has been structured in a way such that there will be only
one controller driver for the whole Owl family series (S500, S700 and
S900 SoCs).

There are 12 physical channels and 46 logical channels supported by the
DMA controller.

The DMA controller also supports 4 software configurable interrupt lines for
the priority based DMA usecase. But the DMA driver supports only 1 interrupt
for simplification. By default, the driver uses Linked list mode for all
transfers. Right now only MEMCPY support has been added and the rest
(SLAVE, CYCLIC) will be added in upcoming patches.

The driver has been tested using dmatest utility on the Bubblegum-96
board.

The DTS patches in this series depends on the pinctrl DTS patches
submitted [1], which is yet to be merged by the platform maintainer
Andreas. Since the DMA driver goes through DMA tree and the relevant
DTS patches goes through ARM-SoC tree, Andreas will pick it up once
it has been reviewed.

For the reference, I have queued up all reviewed dts patches so far
in my repo [2] from which Andreas is picking them for 4.19.

Thanks,
Mani

[1] https://patchwork.kernel.org/patch/10322937/
[2] https://git.linaro.org/people/manivannan.sadhasivam/linux.git/log/?h=s900-for-next

Changes in v3:

As per Vinod's review:

* Removed unused header and API's
* Used GENMASK for defines
* Removed per member comment for structs
* Modified pchan* and dma* API's to use corresponding containers as
  arguments
* Removed error messages regarding the no free channels
* Added devm_free_irq in dma_remove
* Used dmaengine instead of dma for commit titles

Changes in v2:

* Fixed up the multi-line alignments according to `checkpatch --strict`

Manivannan Sadhasivam (4):
  dt-bindings: dmaengine: Add binding for Actions Semi Owl SoCs
  arm64: dts: actions: Add Actions Semi S900 DMA Controller
  dmaengine: Add Actions Semi Owl family S900 DMA driver
  MAINTAINERS: Add entry for Actions Semi Owl SoCs DMA driver

 .../devicetree/bindings/dma/owl-dma.txt       |  47 +
 MAINTAINERS                                   |   2 +
 arch/arm64/boot/dts/actions/s900.dtsi         |  13 +
 drivers/dma/Kconfig                           |   8 +
 drivers/dma/Makefile                          |   1 +
 drivers/dma/owl-dma.c                         | 971 ++++++++++++++++++
 6 files changed, 1042 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/dma/owl-dma.txt
 create mode 100644 drivers/dma/owl-dma.c

-- 
2.17.1

[PATCH v3 1/4] dt-bindings: dmaengine: Add binding for Actions Semi Owl SoCs

[Manivannan Sadhasivam]

Add devicetree binding for Actions Semi Owl SoCs DMA controller.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 .../devicetree/bindings/dma/owl-dma.txt       | 47 +++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/dma/owl-dma.txt

diff --git a/Documentation/devicetree/bindings/dma/owl-dma.txt b/Documentation/devicetree/bindings/dma/owl-dma.txt
new file mode 100644
index 000000000000..03e9bb12b75f
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/owl-dma.txt
@@ -0,0 +1,47 @@
+* Actions Semi Owl SoCs DMA controller
+
+This binding follows the generic DMA bindings defined in dma.txt.
+
+Required properties:
+- compatible: Should be "actions,s900-dma".
+- reg: Should contain DMA registers location and length.
+- interrupts: Should contain 4 interrupts 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: Physical channels supported.
+- dma-requests: Number of DMA request signals supported by the controller.
+                Refer to Documentation/devicetree/bindings/dma/dma.txt
+- clocks: Phandle and Specifier of the clock feeding the DMA controller.
+
+Example:
+
+Controller:
+                dma: dma-controller@e0260000 {
+                        compatible = "actions,s900-dma";
+                        reg = <0x0 0xe0260000 0x0 0x1000>;
+                        interrupts = <GIC_SPI 57 IRQ_TYPE_LEVEL_HIGH>,
+                                     <GIC_SPI 58 IRQ_TYPE_LEVEL_HIGH>,
+                                     <GIC_SPI 59 IRQ_TYPE_LEVEL_HIGH>,
+                                     <GIC_SPI 60 IRQ_TYPE_LEVEL_HIGH>;
+                        #dma-cells = <1>;
+                        dma-channels = <12>;
+                        dma-requests = <46>;
+                        clocks = <&clock CLK_DMAC>;
+                };
+
+Client:
+
+DMA clients connected to the Actions Semi Owl SoCs 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.
+
+uart5: serial@e012a000 {
+        ...
+        dma-names = "tx", "rx";
+        dmas = <&dma 26>, <&dma 27>;
+        ...
+};
-- 
2.17.1

[PATCH v3 2/4] arm64: dts: actions: Add Actions Semi S900 DMA Controller

[Manivannan Sadhasivam]

Add DMA controller node for Actions Semi S900 SoC.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 arch/arm64/boot/dts/actions/s900.dtsi | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/arch/arm64/boot/dts/actions/s900.dtsi b/arch/arm64/boot/dts/actions/s900.dtsi
index 7ae8b931f000..2e8178e50832 100644
--- a/arch/arm64/boot/dts/actions/s900.dtsi
+++ b/arch/arm64/boot/dts/actions/s900.dtsi
@@ -191,6 +191,19 @@
 				     <GIC_SPI 16 IRQ_TYPE_LEVEL_HIGH>;
 		};
 
+		dma: dma-controller@e0260000 {
+			compatible = "actions,s900-dma";
+			reg = <0x0 0xe0260000 0x0 0x1000>;
+			interrupts = <GIC_SPI 57 IRQ_TYPE_LEVEL_HIGH>,
+				     <GIC_SPI 58 IRQ_TYPE_LEVEL_HIGH>,
+				     <GIC_SPI 59 IRQ_TYPE_LEVEL_HIGH>,
+				     <GIC_SPI 60 IRQ_TYPE_LEVEL_HIGH>;
+			#dma-cells = <1>;
+			dma-channels = <12>;
+			dma-requests = <46>;
+			clocks = <&cmu CLK_DMAC>;
+		};
+
 		timer: timer@e0228000 {
 			compatible = "actions,s900-timer";
 			reg = <0x0 0xe0228000 0x0 0x8000>;
-- 
2.17.1

[PATCH v3 3/4] dmaengine: Add Actions Semi Owl family S900 DMA driver

[Manivannan Sadhasivam]

Add Actions Semi Owl family S900 DMA driver.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/dma/Kconfig   |   8 +
 drivers/dma/Makefile  |   1 +
 drivers/dma/owl-dma.c | 971 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 980 insertions(+)
 create mode 100644 drivers/dma/owl-dma.c

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index ca1680afa20a..92a278e6618c 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -413,6 +413,14 @@ config NBPFAXI_DMA
 	help
 	  Support for "Type-AXI" NBPF DMA IPs from Renesas
 
+config OWL_DMA
+	tristate "Actions Semi Owl SoCs DMA support"
+	depends on ARCH_ACTIONS
+	select DMA_ENGINE
+	select DMA_VIRTUAL_CHANNELS
+	help
+	  Enable support for the Actions Semi Owl SoCs DMA controller.
+
 config PCH_DMA
 	tristate "Intel EG20T PCH / LAPIS Semicon IOH(ML7213/ML7223/ML7831) DMA"
 	depends on PCI && (X86_32 || COMPILE_TEST)
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index 203a99d68315..c91702d88b95 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -52,6 +52,7 @@ obj-$(CONFIG_MV_XOR_V2) += mv_xor_v2.o
 obj-$(CONFIG_MXS_DMA) += mxs-dma.o
 obj-$(CONFIG_MX3_IPU) += ipu/
 obj-$(CONFIG_NBPFAXI_DMA) += nbpfaxi.o
+obj-$(CONFIG_OWL_DMA) += owl-dma.o
 obj-$(CONFIG_PCH_DMA) += pch_dma.o
 obj-$(CONFIG_PL330_DMA) += pl330.o
 obj-$(CONFIG_PPC_BESTCOMM) += bestcomm/
diff --git a/drivers/dma/owl-dma.c b/drivers/dma/owl-dma.c
new file mode 100644
index 000000000000..7812a6338acd
--- /dev/null
+++ b/drivers/dma/owl-dma.c
@@ -0,0 +1,971 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// Actions Semi Owl SoCs DMA driver
+//
+// Copyright (c) 2014 Actions Semi Inc.
+// Author: David Liu <liuwei@actions-semi.com>
+//
+// Copyright (c) 2018 Linaro Ltd.
+// Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmapool.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/slab.h>
+#include "virt-dma.h"
+
+#define OWL_DMA_FRAME_MAX_LENGTH		0xfffff
+
+/* Global DMA Controller Registers */
+#define OWL_DMA_IRQ_PD0				0x00
+#define OWL_DMA_IRQ_PD1				0x04
+#define OWL_DMA_IRQ_PD2				0x08
+#define OWL_DMA_IRQ_PD3				0x0C
+#define OWL_DMA_IRQ_EN0				0x10
+#define OWL_DMA_IRQ_EN1				0x14
+#define OWL_DMA_IRQ_EN2				0x18
+#define OWL_DMA_IRQ_EN3				0x1C
+#define OWL_DMA_SECURE_ACCESS_CTL		0x20
+#define OWL_DMA_NIC_QOS				0x24
+#define OWL_DMA_DBGSEL				0x28
+#define OWL_DMA_IDLE_STAT			0x2C
+
+/* Channel Registers */
+#define OWL_DMA_CHAN_BASE(i)			(0x100 + (i) * 0x100)
+#define OWL_DMAX_MODE				0x00
+#define OWL_DMAX_SOURCE				0x04
+#define OWL_DMAX_DESTINATION			0x08
+#define OWL_DMAX_FRAME_LEN			0x0C
+#define OWL_DMAX_FRAME_CNT			0x10
+#define OWL_DMAX_REMAIN_FRAME_CNT		0x14
+#define OWL_DMAX_REMAIN_CNT			0x18
+#define OWL_DMAX_SOURCE_STRIDE			0x1C
+#define OWL_DMAX_DESTINATION_STRIDE		0x20
+#define OWL_DMAX_START				0x24
+#define OWL_DMAX_PAUSE				0x28
+#define OWL_DMAX_CHAINED_CTL			0x2C
+#define OWL_DMAX_CONSTANT			0x30
+#define OWL_DMAX_LINKLIST_CTL			0x34
+#define OWL_DMAX_NEXT_DESCRIPTOR		0x38
+#define OWL_DMAX_CURRENT_DESCRIPTOR_NUM		0x3C
+#define OWL_DMAX_INT_CTL			0x40
+#define OWL_DMAX_INT_STATUS			0x44
+#define OWL_DMAX_CURRENT_SOURCE_POINTER		0x48
+#define OWL_DMAX_CURRENT_DESTINATION_POINTER	0x4C
+
+/* OWL_DMAX_MODE Bits */
+#define OWL_DMA_MODE_TS(x)			(((x) & GENMASK(5, 0)) << 0)
+#define OWL_DMA_MODE_ST(x)			(((x) & GENMASK(1, 0)) << 8)
+#define	OWL_DMA_MODE_ST_DEV			OWL_DMA_MODE_ST(0)
+#define	OWL_DMA_MODE_ST_DCU			OWL_DMA_MODE_ST(2)
+#define	OWL_DMA_MODE_ST_SRAM			OWL_DMA_MODE_ST(3)
+#define OWL_DMA_MODE_DT(x)			(((x) & GENMASK(1, 0)) << 10)
+#define	OWL_DMA_MODE_DT_DEV			OWL_DMA_MODE_DT(0)
+#define	OWL_DMA_MODE_DT_DCU			OWL_DMA_MODE_DT(2)
+#define	OWL_DMA_MODE_DT_SRAM			OWL_DMA_MODE_DT(3)
+#define OWL_DMA_MODE_SAM(x)			(((x) & GENMASK(1, 0)) << 16)
+#define	OWL_DMA_MODE_SAM_CONST			OWL_DMA_MODE_SAM(0)
+#define	OWL_DMA_MODE_SAM_INC			OWL_DMA_MODE_SAM(1)
+#define	OWL_DMA_MODE_SAM_STRIDE			OWL_DMA_MODE_SAM(2)
+#define OWL_DMA_MODE_DAM(x)			(((x) & GENMASK(1, 0)) << 18)
+#define	OWL_DMA_MODE_DAM_CONST			OWL_DMA_MODE_DAM(0)
+#define	OWL_DMA_MODE_DAM_INC			OWL_DMA_MODE_DAM(1)
+#define	OWL_DMA_MODE_DAM_STRIDE			OWL_DMA_MODE_DAM(2)
+#define OWL_DMA_MODE_PW(x)			(((x) & GENMASK(2, 0)) << 20)
+#define OWL_DMA_MODE_CB				BIT(23)
+#define OWL_DMA_MODE_NDDBW(x)			(((x) & 0x1) << 28)
+#define	OWL_DMA_MODE_NDDBW_32BIT		OWL_DMA_MODE_NDDBW(0)
+#define	OWL_DMA_MODE_NDDBW_8BIT			OWL_DMA_MODE_NDDBW(1)
+#define OWL_DMA_MODE_CFE			BIT(29)
+#define OWL_DMA_MODE_LME			BIT(30)
+#define OWL_DMA_MODE_CME			BIT(31)
+
+/* OWL_DMAX_LINKLIST_CTL Bits */
+#define OWL_DMA_LLC_SAV(x)			(((x) & GENMASK(1, 0)) << 8)
+#define	OWL_DMA_LLC_SAV_INC			OWL_DMA_LLC_SAV(0)
+#define	OWL_DMA_LLC_SAV_LOAD_NEXT		OWL_DMA_LLC_SAV(1)
+#define	OWL_DMA_LLC_SAV_LOAD_PREV		OWL_DMA_LLC_SAV(2)
+#define OWL_DMA_LLC_DAV(x)			(((x) & GENMASK(1, 0)) << 10)
+#define	OWL_DMA_LLC_DAV_INC			OWL_DMA_LLC_DAV(0)
+#define	OWL_DMA_LLC_DAV_LOAD_NEXT		OWL_DMA_LLC_DAV(1)
+#define	OWL_DMA_LLC_DAV_LOAD_PREV		OWL_DMA_LLC_DAV(2)
+#define OWL_DMA_LLC_SUSPEND			BIT(16)
+
+/* OWL_DMAX_INT_CTL Bits */
+#define OWL_DMA_INTCTL_BLOCK			BIT(0)
+#define OWL_DMA_INTCTL_SUPER_BLOCK		BIT(1)
+#define OWL_DMA_INTCTL_FRAME			BIT(2)
+#define OWL_DMA_INTCTL_HALF_FRAME		BIT(3)
+#define OWL_DMA_INTCTL_LAST_FRAME		BIT(4)
+
+/* OWL_DMAX_INT_STATUS Bits */
+#define OWL_DMA_INTSTAT_BLOCK			BIT(0)
+#define OWL_DMA_INTSTAT_SUPER_BLOCK		BIT(1)
+#define OWL_DMA_INTSTAT_FRAME			BIT(2)
+#define OWL_DMA_INTSTAT_HALF_FRAME		BIT(3)
+#define OWL_DMA_INTSTAT_LAST_FRAME		BIT(4)
+
+/* Pack shift and newshift in a single word */
+#define BIT_FIELD(val, width, shift, newshift)	\
+		((((val) >> (shift)) & ((BIT(width)) - 1)) << (newshift))
+
+/**
+ * struct owl_dma_lli_hw - Hardware link list for dma transfer
+ * @next_lli: physical address of the next link list
+ * @saddr: source physical address
+ * @daddr: destination physical address
+ * @flen: frame length
+ * @fcnt: frame count
+ * @src_stride: source stride
+ * @dst_stride: destination stride
+ * @ctrla: dma_mode and linklist ctrl config
+ * @ctrlb: interrupt config
+ * @const_num: data for constant fill
+ */
+struct owl_dma_lli_hw {
+	u32	next_lli;
+	u32	saddr;
+	u32	daddr;
+	u32	flen:20;
+	u32	fcnt:12;
+	u32	src_stride;
+	u32	dst_stride;
+	u32	ctrla;
+	u32	ctrlb;
+	u32	const_num;
+};
+
+/**
+ * struct owl_dma_lli - Link list for dma transfer
+ * @hw: hardware link list
+ * @phys: physical address of hardware link list
+ * @node: node for txd's lli_list
+ */
+struct owl_dma_lli {
+	struct  owl_dma_lli_hw	hw;
+	dma_addr_t		phys;
+	struct list_head	node;
+};
+
+/**
+ * struct owl_dma_txd - Wrapper for struct dma_async_tx_descriptor
+ * @vd: virtual DMA descriptor
+ * @lli_list: link list of lli nodes
+ */
+struct owl_dma_txd {
+	struct virt_dma_desc	vd;
+	struct list_head	lli_list;
+};
+
+/**
+ * struct owl_dma_pchan - Holder for the physical channels
+ * @id: physical index to this channel
+ * @base: virtual memory base for the dma channel
+ * @vchan: the virtual channel currently being served by this physical channel
+ * @lock: a lock to use when altering an instance of this struct
+ */
+struct owl_dma_pchan {
+	u32			id;
+	void __iomem		*base;
+	struct owl_dma_vchan	*vchan;
+	spinlock_t		lock;
+};
+
+/**
+ * struct owl_dma_pchan - Wrapper for DMA ENGINE channel
+ * @vc: wrappped virtual channel
+ * @pchan: the physical channel utilized by this channel
+ * @txd: active transaction on this channel
+ */
+struct owl_dma_vchan {
+	struct virt_dma_chan	vc;
+	struct owl_dma_pchan	*pchan;
+	struct owl_dma_txd	*txd;
+};
+
+/**
+ * struct owl_dma - Holder for the Owl DMA controller
+ * @dma: dma engine for this instance
+ * @base: virtual memory base for the DMA controller
+ * @clk: clock for the DMA controller
+ * @lock: a lock to use when change DMA controller global register
+ * @lli_pool: a pool for the LLI descriptors
+ * @nr_pchans: the number of physical channels
+ * @pchans: array of data for the physical channels
+ * @nr_vchans: the number of physical channels
+ * @vchans: array of data for the physical channels
+ */
+struct owl_dma {
+	struct dma_device	dma;
+	void __iomem		*base;
+	struct clk		*clk;
+	spinlock_t		lock;
+	struct dma_pool		*lli_pool;
+	int			irq;
+
+	unsigned int		nr_pchans;
+	struct owl_dma_pchan	*pchans;
+
+	unsigned int		nr_vchans;
+	struct owl_dma_vchan	*vchans;
+};
+
+static void pchan_update(struct owl_dma_pchan *pchan, u32 reg,
+			 u32 val, bool state)
+{
+	u32 regval;
+
+	regval = readl(pchan->base + reg);
+
+	if (state)
+		regval |= val;
+	else
+		regval &= ~val;
+
+	writel(val, pchan->base + reg);
+}
+
+static void pchan_writel(struct owl_dma_pchan *pchan, u32 reg, u32 data)
+{
+	writel(data, pchan->base + reg);
+}
+
+static u32 pchan_readl(struct owl_dma_pchan *pchan, u32 reg)
+{
+	return readl(pchan->base + reg);
+}
+
+static void dma_update(struct owl_dma *od, u32 reg, u32 val, bool state)
+{
+	u32 regval;
+
+	regval = readl(od->base + reg);
+
+	if (state)
+		regval |= val;
+	else
+		regval &= ~val;
+
+	writel(val, od->base + reg);
+}
+
+static void dma_writel(struct owl_dma *od, u32 reg, u32 data)
+{
+	writel(data, od->base + reg);
+}
+
+static u32 dma_readl(struct owl_dma *od, u32 reg)
+{
+	return readl(od->base + reg);
+}
+
+static inline struct owl_dma *to_owl_dma(struct dma_device *dd)
+{
+	return container_of(dd, struct owl_dma, dma);
+}
+
+static struct device *chan2dev(struct dma_chan *chan)
+{
+	return &chan->dev->device;
+}
+
+static inline struct owl_dma_vchan *to_owl_vchan(struct dma_chan *chan)
+{
+	return container_of(chan, struct owl_dma_vchan, vc.chan);
+}
+
+static inline struct owl_dma_txd *to_owl_txd(struct dma_async_tx_descriptor *tx)
+{
+	return container_of(tx, struct owl_dma_txd, vd.tx);
+}
+
+static inline u32 llc_hw_ctrla(u32 mode, u32 llc_ctl)
+{
+	u32 ctl;
+
+	ctl = BIT_FIELD(mode, 4, 28, 28) |
+	      BIT_FIELD(mode, 8, 16, 20) |
+	      BIT_FIELD(mode, 4, 8, 16) |
+	      BIT_FIELD(mode, 6, 0, 10) |
+	      BIT_FIELD(llc_ctl, 2, 10, 8) |
+	      BIT_FIELD(llc_ctl, 2, 8, 6);
+
+	return ctl;
+}
+
+static inline u32 llc_hw_ctrlb(u32 int_ctl)
+{
+	u32 ctl;
+
+	ctl = BIT_FIELD(int_ctl, 7, 0, 18);
+
+	return ctl;
+}
+
+static void owl_dma_free_lli(struct owl_dma *od,
+			     struct owl_dma_lli *lli)
+{
+	list_del(&lli->node);
+	dma_pool_free(od->lli_pool, lli, lli->phys);
+}
+
+static struct owl_dma_lli *owl_dma_alloc_lli(struct owl_dma *od)
+{
+	struct owl_dma_lli *lli;
+	dma_addr_t phys;
+
+	lli = dma_pool_alloc(od->lli_pool, GFP_NOWAIT, &phys);
+	if (!lli)
+		return NULL;
+
+	INIT_LIST_HEAD(&lli->node);
+	lli->phys = phys;
+
+	return lli;
+}
+
+static struct owl_dma_lli *owl_dma_add_lli(struct owl_dma_txd *txd,
+					   struct owl_dma_lli *prev,
+					   struct owl_dma_lli *next)
+{
+	list_add_tail(&next->node, &txd->lli_list);
+
+	if (prev) {
+		prev->hw.next_lli = next->phys;
+		prev->hw.ctrla |= llc_hw_ctrla(OWL_DMA_MODE_LME, 0);
+	}
+
+	return next;
+}
+
+static inline int owl_dma_cfg_lli(struct owl_dma_vchan *vchan,
+				  struct owl_dma_lli *lli,
+				  dma_addr_t src, dma_addr_t dst,
+				  u32 len, enum dma_transfer_direction dir)
+{
+	struct owl_dma_lli_hw *hw = &lli->hw;
+	u32 mode;
+
+	mode = OWL_DMA_MODE_PW(0);
+
+	switch (dir) {
+	case DMA_MEM_TO_MEM:
+		mode |= OWL_DMA_MODE_TS(0) | OWL_DMA_MODE_ST_DCU |
+			OWL_DMA_MODE_DT_DCU | OWL_DMA_MODE_SAM_INC |
+			OWL_DMA_MODE_DAM_INC;
+
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	hw->next_lli = 0; /* One link list by default */
+	hw->saddr = src;
+	hw->daddr = dst;
+
+	hw->fcnt = 1; /* Frame count fixed as 1 */
+	hw->flen = len; /* Max frame length is 1MB */
+	hw->src_stride = 0;
+	hw->dst_stride = 0;
+	hw->ctrla = llc_hw_ctrla(mode,
+				 OWL_DMA_LLC_SAV_LOAD_NEXT |
+				 OWL_DMA_LLC_DAV_LOAD_NEXT);
+
+	hw->ctrlb = llc_hw_ctrlb(OWL_DMA_INTCTL_SUPER_BLOCK);
+
+	return 0;
+}
+
+static struct owl_dma_pchan *owl_dma_get_pchan(struct owl_dma *od,
+					       struct owl_dma_vchan *vchan)
+{
+	struct owl_dma_pchan *pchan = NULL;
+	unsigned long flags;
+	int i;
+
+	for (i = 0; i < od->nr_pchans; i++) {
+		pchan = &od->pchans[i];
+
+		spin_lock_irqsave(&pchan->lock, flags);
+		if (!pchan->vchan) {
+			pchan->vchan = vchan;
+			spin_unlock_irqrestore(&pchan->lock, flags);
+			break;
+		}
+
+		spin_unlock_irqrestore(&pchan->lock, flags);
+	}
+
+	return pchan;
+}
+
+static int owl_dma_pchan_busy(struct owl_dma *od, struct owl_dma_pchan *pchan)
+{
+	unsigned int val;
+
+	val = dma_readl(od, OWL_DMA_IDLE_STAT);
+
+	return !(val & (1 << pchan->id));
+}
+
+static void owl_dma_terminate_pchan(struct owl_dma *od,
+				    struct owl_dma_pchan *pchan)
+{
+	unsigned long flags;
+	u32 irq_pd;
+
+	pchan_writel(pchan, OWL_DMAX_START, 0);
+	pchan_update(pchan, OWL_DMAX_INT_STATUS, 0xff, false);
+
+	spin_lock_irqsave(&od->lock, flags);
+	dma_update(od, OWL_DMA_IRQ_EN0, (1 << pchan->id), false);
+
+	irq_pd = dma_readl(od, OWL_DMA_IRQ_PD0);
+	if (irq_pd & (1 << pchan->id)) {
+		dev_warn(od->dma.dev,
+			 "terminating pchan %d that still has pending irq\n",
+			 pchan->id);
+		dma_writel(od, OWL_DMA_IRQ_PD0, (1 << pchan->id));
+	}
+
+	pchan->vchan = NULL;
+
+	spin_unlock_irqrestore(&od->lock, flags);
+}
+
+static int owl_dma_start_next_txd(struct owl_dma_vchan *vchan)
+{
+	struct owl_dma *od = to_owl_dma(vchan->vc.chan.device);
+	struct virt_dma_desc *vd = vchan_next_desc(&vchan->vc);
+	struct owl_dma_pchan *pchan = vchan->pchan;
+	struct owl_dma_txd *txd = to_owl_txd(&vd->tx);
+	struct owl_dma_lli *lli;
+	unsigned long flags;
+	u32 int_ctl;
+
+	list_del(&vd->node);
+
+	vchan->txd = txd;
+
+	/* Wait for channel inactive */
+	while (owl_dma_pchan_busy(od, pchan))
+		cpu_relax();
+
+	lli = list_first_entry(&txd->lli_list,
+			       struct owl_dma_lli, node);
+
+	int_ctl = OWL_DMA_INTCTL_SUPER_BLOCK;
+
+	pchan_writel(pchan, OWL_DMAX_MODE, OWL_DMA_MODE_LME);
+	pchan_writel(pchan, OWL_DMAX_LINKLIST_CTL,
+		     OWL_DMA_LLC_SAV_LOAD_NEXT | OWL_DMA_LLC_DAV_LOAD_NEXT);
+	pchan_writel(pchan, OWL_DMAX_NEXT_DESCRIPTOR, lli->phys);
+	pchan_writel(pchan, OWL_DMAX_INT_CTL, int_ctl);
+
+	/* Clear IRQ status for this pchan */
+	pchan_update(pchan, OWL_DMAX_INT_STATUS, 0xff, false);
+
+	spin_lock_irqsave(&od->lock, flags);
+
+	dma_update(od, OWL_DMA_IRQ_EN0, (1 << pchan->id), true);
+
+	spin_unlock_irqrestore(&od->lock, flags);
+
+	dev_dbg(chan2dev(&vchan->vc.chan), "starting pchan %d\n", pchan->id);
+
+	/* Start DMA transfer for this pchan */
+	pchan_writel(pchan, OWL_DMAX_START, 0x1);
+
+	return 0;
+}
+
+static void owl_dma_phy_free(struct owl_dma *od, struct owl_dma_vchan *vchan)
+{
+	/* Ensure that the physical channel is stopped */
+	owl_dma_terminate_pchan(od, vchan->pchan);
+
+	vchan->pchan = NULL;
+}
+
+static irqreturn_t owl_dma_interrupt(int irq, void *dev_id)
+{
+	struct owl_dma *od = dev_id;
+	struct owl_dma_vchan *vchan;
+	struct owl_dma_pchan *pchan;
+	unsigned long pending;
+	int i;
+	unsigned int global_irq_pending, chan_irq_pending;
+
+	spin_lock(&od->lock);
+
+	pending = dma_readl(od, OWL_DMA_IRQ_PD0);
+
+	/* Clear IRQ status for each pchan */
+	for_each_set_bit(i, &pending, od->nr_pchans) {
+		pchan = &od->pchans[i];
+		pchan_update(pchan, OWL_DMAX_INT_STATUS, 0xff, false);
+	}
+
+	/* Clear pending IRQ */
+	dma_writel(od, OWL_DMA_IRQ_PD0, pending);
+
+	/* Check missed pending IRQ */
+	for (i = 0; i < od->nr_pchans; i++) {
+		pchan = &od->pchans[i];
+		chan_irq_pending = pchan_readl(pchan, OWL_DMAX_INT_CTL) &
+				   pchan_readl(pchan, OWL_DMAX_INT_STATUS);
+
+		/* Dummy read to ensure OWL_DMA_IRQ_PD0 value is updated */
+		dma_readl(od, OWL_DMA_IRQ_PD0);
+
+		global_irq_pending = dma_readl(od, OWL_DMA_IRQ_PD0);
+
+		if (chan_irq_pending && !(global_irq_pending & BIT(i)))	{
+			dev_dbg(od->dma.dev,
+				"global and channel IRQ pending match err\n");
+
+			/* Clear IRQ status for this pchan */
+			pchan_update(pchan, OWL_DMAX_INT_STATUS,
+				     0xff, false);
+
+			/* Update global IRQ pending */
+			pending |= BIT(i);
+		}
+	}
+
+	spin_unlock(&od->lock);
+
+	for_each_set_bit(i, &pending, od->nr_pchans) {
+		struct owl_dma_txd *txd;
+
+		pchan = &od->pchans[i];
+
+		vchan = pchan->vchan;
+		if (!vchan) {
+			dev_warn(od->dma.dev, "no vchan attached on pchan %d\n",
+				 pchan->id);
+			continue;
+		}
+
+		spin_lock(&vchan->vc.lock);
+
+		txd = vchan->txd;
+		if (txd) {
+			vchan->txd = NULL;
+
+			vchan_cookie_complete(&txd->vd);
+
+			/*
+			 * Start the next descriptor (if any),
+			 * otherwise free this channel.
+			 */
+			if (vchan_next_desc(&vchan->vc))
+				owl_dma_start_next_txd(vchan);
+			else
+				owl_dma_phy_free(od, vchan);
+		}
+
+		spin_unlock(&vchan->vc.lock);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static void owl_dma_free_txd(struct owl_dma *od, struct owl_dma_txd *txd)
+{
+	struct owl_dma_lli *lli, *_lli;
+
+	if (unlikely(!txd))
+		return;
+
+	list_for_each_entry_safe(lli, _lli, &txd->lli_list, node)
+		owl_dma_free_lli(od, lli);
+
+	kfree(txd);
+}
+
+static void owl_dma_desc_free(struct virt_dma_desc *vd)
+{
+	struct owl_dma *od = to_owl_dma(vd->tx.chan->device);
+	struct owl_dma_txd *txd = to_owl_txd(&vd->tx);
+
+	owl_dma_free_txd(od, txd);
+}
+
+static int owl_dma_terminate_all(struct dma_chan *chan)
+{
+	struct owl_dma *od = to_owl_dma(chan->device);
+	struct owl_dma_vchan *vchan = to_owl_vchan(chan);
+	unsigned long flags;
+	LIST_HEAD(head);
+
+	spin_lock_irqsave(&vchan->vc.lock, flags);
+
+	if (vchan->pchan)
+		owl_dma_phy_free(od, vchan);
+
+	if (vchan->txd) {
+		owl_dma_desc_free(&vchan->txd->vd);
+		vchan->txd = NULL;
+	}
+
+	vchan_get_all_descriptors(&vchan->vc, &head);
+	vchan_dma_desc_free_list(&vchan->vc, &head);
+
+	spin_unlock_irqrestore(&vchan->vc.lock, flags);
+
+	return 0;
+}
+
+static u32 owl_dma_getbytes_chan(struct owl_dma_vchan *vchan)
+{
+	struct owl_dma_pchan *pchan;
+	struct owl_dma_txd *txd;
+	struct owl_dma_lli *lli;
+	unsigned int next_lli_phy;
+	size_t bytes;
+
+	pchan = vchan->pchan;
+	txd = vchan->txd;
+
+	if (!pchan || !txd)
+		return 0;
+
+	/* Get remain count of current node in link list */
+	bytes = pchan_readl(pchan, OWL_DMAX_REMAIN_CNT);
+
+	/* Loop through the preceding nodes to get total remaining bytes */
+	if (pchan_readl(pchan, OWL_DMAX_MODE) & OWL_DMA_MODE_LME) {
+		next_lli_phy = pchan_readl(pchan, OWL_DMAX_NEXT_DESCRIPTOR);
+		list_for_each_entry(lli, &txd->lli_list, node) {
+			/* Start from the next active node */
+			if (lli->phys == next_lli_phy) {
+				list_for_each_entry(lli, &txd->lli_list, node)
+					bytes += lli->hw.flen;
+				break;
+			}
+		}
+	}
+
+	return bytes;
+}
+
+static enum dma_status owl_dma_tx_status(struct dma_chan *chan,
+					 dma_cookie_t cookie,
+					 struct dma_tx_state *state)
+{
+	struct owl_dma_vchan *vchan = to_owl_vchan(chan);
+	struct owl_dma_lli *lli;
+	struct virt_dma_desc *vd;
+	struct owl_dma_txd *txd;
+	enum dma_status ret;
+	unsigned long flags;
+	size_t bytes = 0;
+
+	ret = dma_cookie_status(chan, cookie, state);
+	if (ret == DMA_COMPLETE || !state)
+		return ret;
+
+	spin_lock_irqsave(&vchan->vc.lock, flags);
+
+	vd = vchan_find_desc(&vchan->vc, cookie);
+	if (vd) {
+		txd = to_owl_txd(&vd->tx);
+		list_for_each_entry(lli, &txd->lli_list, node)
+			bytes += lli->hw.flen;
+	} else {
+		bytes = owl_dma_getbytes_chan(vchan);
+	}
+
+	spin_unlock_irqrestore(&vchan->vc.lock, flags);
+
+	dma_set_residue(state, bytes);
+
+	return ret;
+}
+
+static void owl_dma_phy_alloc_and_start(struct owl_dma_vchan *vchan)
+{
+	struct owl_dma *od = to_owl_dma(vchan->vc.chan.device);
+	struct owl_dma_pchan *pchan;
+
+	pchan = owl_dma_get_pchan(od, vchan);
+	if (!pchan)
+		return;
+
+	dev_dbg(od->dma.dev, "allocated pchan %d\n", pchan->id);
+
+	vchan->pchan = pchan;
+	owl_dma_start_next_txd(vchan);
+}
+
+static void owl_dma_issue_pending(struct dma_chan *chan)
+{
+	struct owl_dma_vchan *vchan = to_owl_vchan(chan);
+	unsigned long flags;
+
+	spin_lock_irqsave(&vchan->vc.lock, flags);
+	if (vchan_issue_pending(&vchan->vc)) {
+		if (!vchan->pchan)
+			owl_dma_phy_alloc_and_start(vchan);
+	}
+	spin_unlock_irqrestore(&vchan->vc.lock, flags);
+}
+
+static struct dma_async_tx_descriptor
+		*owl_dma_prep_memcpy(struct dma_chan *chan,
+				     dma_addr_t dst, dma_addr_t src,
+				     size_t len, unsigned long flags)
+{
+	struct owl_dma *od = to_owl_dma(chan->device);
+	struct owl_dma_vchan *vchan = to_owl_vchan(chan);
+	struct owl_dma_txd *txd;
+	struct owl_dma_lli *lli, *prev = NULL;
+	size_t offset, bytes;
+	int ret;
+
+	if (!len)
+		return NULL;
+
+	txd = kzalloc(sizeof(*txd), GFP_NOWAIT);
+	if (!txd)
+		return NULL;
+
+	INIT_LIST_HEAD(&txd->lli_list);
+
+	/* Process the transfer as frame by frame */
+	for (offset = 0; offset < len; offset += bytes) {
+		lli = owl_dma_alloc_lli(od);
+		if (!lli) {
+			dev_warn(chan2dev(chan), "failed to allocate lli\n");
+			goto err_txd_free;
+		}
+
+		bytes = min_t(size_t, (len - offset), OWL_DMA_FRAME_MAX_LENGTH);
+
+		ret = owl_dma_cfg_lli(vchan, lli, src + offset, dst + offset,
+				      bytes, DMA_MEM_TO_MEM);
+		if (ret) {
+			dev_warn(chan2dev(chan), "failed to config lli\n");
+			goto err_txd_free;
+		}
+
+		prev = owl_dma_add_lli(txd, prev, lli);
+	}
+
+	return vchan_tx_prep(&vchan->vc, &txd->vd, flags);
+
+err_txd_free:
+	owl_dma_free_txd(od, txd);
+	return NULL;
+}
+
+static void owl_dma_free_chan_resources(struct dma_chan *chan)
+{
+	struct owl_dma_vchan *vchan = to_owl_vchan(chan);
+
+	/* Ensure all queued descriptors are freed */
+	vchan_free_chan_resources(&vchan->vc);
+}
+
+static inline void owl_dma_free(struct owl_dma *od)
+{
+	struct owl_dma_vchan *vchan = NULL;
+	struct owl_dma_vchan *next;
+
+	list_for_each_entry_safe(vchan,
+				 next, &od->dma.channels, vc.chan.device_node) {
+		list_del(&vchan->vc.chan.device_node);
+		tasklet_kill(&vchan->vc.task);
+	}
+}
+
+static int owl_dma_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct owl_dma *od;
+	struct resource *res;
+	int ret, i, nr_channels, nr_requests;
+
+	od = devm_kzalloc(&pdev->dev, sizeof(*od), GFP_KERNEL);
+	if (!od)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
+
+	od->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(od->base))
+		return PTR_ERR(od->base);
+
+	ret = of_property_read_u32(np, "dma-channels", &nr_channels);
+	if (ret) {
+		dev_err(&pdev->dev, "can't get dma-channels\n");
+		return ret;
+	}
+
+	ret = of_property_read_u32(np, "dma-requests", &nr_requests);
+	if (ret) {
+		dev_err(&pdev->dev, "can't get dma-requests\n");
+		return ret;
+	}
+
+	dev_info(&pdev->dev, "dma-channels %d, dma-requests %d\n",
+		 nr_channels, nr_requests);
+
+	od->nr_pchans = nr_channels;
+	od->nr_vchans = nr_requests;
+
+	pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
+
+	platform_set_drvdata(pdev, od);
+	spin_lock_init(&od->lock);
+
+	dma_cap_set(DMA_MEMCPY, od->dma.cap_mask);
+
+	od->dma.dev = &pdev->dev;
+	od->dma.device_free_chan_resources = owl_dma_free_chan_resources;
+	od->dma.device_tx_status = owl_dma_tx_status;
+	od->dma.device_issue_pending = owl_dma_issue_pending;
+	od->dma.device_prep_dma_memcpy = owl_dma_prep_memcpy;
+	od->dma.device_terminate_all = owl_dma_terminate_all;
+	od->dma.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
+	od->dma.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
+	od->dma.directions = BIT(DMA_MEM_TO_MEM);
+	od->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
+
+	INIT_LIST_HEAD(&od->dma.channels);
+
+	od->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(od->clk)) {
+		dev_err(&pdev->dev, "unable to get clock\n");
+		return PTR_ERR(od->clk);
+	}
+
+	/*
+	 * Eventhough the DMA controller is capable of generating 4
+	 * IRQ's for DMA priority feature, we only use 1 IRQ for
+	 * simplification.
+	 */
+	od->irq = platform_get_irq(pdev, 0);
+	ret = devm_request_irq(&pdev->dev, od->irq, owl_dma_interrupt, 0,
+			       dev_name(&pdev->dev), od);
+	if (ret) {
+		dev_err(&pdev->dev, "unable to request IRQ\n");
+		return ret;
+	}
+
+	/* Init physical channel */
+	od->pchans = devm_kcalloc(&pdev->dev, od->nr_pchans,
+				  sizeof(struct owl_dma_pchan), GFP_KERNEL);
+	if (!od->pchans)
+		return -ENOMEM;
+
+	for (i = 0; i < od->nr_pchans; i++) {
+		struct owl_dma_pchan *pchan = &od->pchans[i];
+
+		pchan->id = i;
+		pchan->base = od->base + OWL_DMA_CHAN_BASE(i);
+	}
+
+	/* Init virtual channel */
+	od->vchans = devm_kcalloc(&pdev->dev, od->nr_vchans,
+				  sizeof(struct owl_dma_vchan), GFP_KERNEL);
+	if (!od->vchans)
+		return -ENOMEM;
+
+	for (i = 0; i < od->nr_vchans; i++) {
+		struct owl_dma_vchan *vchan = &od->vchans[i];
+
+		vchan->vc.desc_free = owl_dma_desc_free;
+		vchan_init(&vchan->vc, &od->dma);
+	}
+
+	/* Create a pool of consistent memory blocks for hardware descriptors */
+	od->lli_pool = dma_pool_create(dev_name(od->dma.dev), od->dma.dev,
+				       sizeof(struct owl_dma_lli),
+				       __alignof__(struct owl_dma_lli),
+				       0);
+	if (!od->lli_pool) {
+		dev_err(&pdev->dev, "unable to allocate DMA descriptor pool\n");
+		return -ENOMEM;
+	}
+
+	clk_prepare_enable(od->clk);
+
+	ret = dma_async_device_register(&od->dma);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register DMA engine device\n");
+		goto err_pool_free;
+	}
+
+	return 0;
+
+err_pool_free:
+	clk_disable_unprepare(od->clk);
+	dma_pool_destroy(od->lli_pool);
+
+	return ret;
+}
+
+static int owl_dma_remove(struct platform_device *pdev)
+{
+	struct owl_dma *od = platform_get_drvdata(pdev);
+
+	dma_async_device_unregister(&od->dma);
+
+	/* Mask all interrupts for this execution environment */
+	dma_writel(od, OWL_DMA_IRQ_EN0, 0x0);
+
+	/* Make sure we won't have any further interrupts */
+	devm_free_irq(od->dma.dev, od->irq, od);
+
+	owl_dma_free(od);
+
+	clk_disable_unprepare(od->clk);
+
+	return 0;
+}
+
+static const struct of_device_id owl_dma_match[] = {
+	{ .compatible = "actions,s900-dma", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, owl_dma_match);
+
+static struct platform_driver owl_dma_driver = {
+	.probe	= owl_dma_probe,
+	.remove	= owl_dma_remove,
+	.driver = {
+		.name = "dma-owl",
+		.of_match_table = of_match_ptr(owl_dma_match),
+	},
+};
+
+static int owl_dma_init(void)
+{
+	return platform_driver_register(&owl_dma_driver);
+}
+subsys_initcall(owl_dma_init);
+
+static void __exit owl_dma_exit(void)
+{
+	platform_driver_unregister(&owl_dma_driver);
+}
+module_exit(owl_dma_exit);
+
+MODULE_AUTHOR("David Liu <liuwei@actions-semi.com>");
+MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
+MODULE_DESCRIPTION("Actions Semi Owl SoCs DMA driver");
+MODULE_LICENSE("GPL");
-- 
2.17.1

[PATCH v3 4/4] MAINTAINERS: Add entry for Actions Semi Owl SoCs DMA driver

[Manivannan Sadhasivam]

Add entry for Actions Semi Owl SoCs DMA driver under ARM/ACTIONS.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 MAINTAINERS | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 09b54e9ebc6f..56d9c7715c2a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1145,12 +1145,14 @@ F:	arch/arm/boot/dts/owl-*
 F:	arch/arm64/boot/dts/actions/
 F:	drivers/clk/actions/
 F:	drivers/clocksource/owl-*
+F:	drivers/dma/owl-dma.c
 F:	drivers/pinctrl/actions/*
 F:	drivers/soc/actions/
 F:	include/dt-bindings/power/owl-*
 F:	include/linux/soc/actions/
 F:	Documentation/devicetree/bindings/arm/actions.txt
 F:	Documentation/devicetree/bindings/clock/actions,s900-cmu.txt
+F:	Documentation/devicetree/bindings/dma/owl-dma.txt
 F:	Documentation/devicetree/bindings/pinctrl/actions,s900-pinctrl.txt
 F:	Documentation/devicetree/bindings/power/actions,owl-sps.txt
 F:	Documentation/devicetree/bindings/timer/actions,owl-timer.txt
-- 
2.17.1

Re: [PATCH v3 1/4] dt-bindings: dmaengine: Add binding for Actions Semi Owl SoCs

[Rob Herring]

On Thu, Jul 26, 2018 at 10:36:55AM +0530, Manivannan Sadhasivam wrote:
> Add devicetree binding for Actions Semi Owl SoCs DMA controller.
> 
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---
>  .../devicetree/bindings/dma/owl-dma.txt       | 47 +++++++++++++++++++
>  1 file changed, 47 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/dma/owl-dma.txt

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

Re: [PATCH v3 1/4] dt-bindings: dmaengine: Add binding for Actions Semi Owl SoCs

[Vinod]

On 26-07-18, 10:36, Manivannan Sadhasivam wrote:
> Add devicetree binding for Actions Semi Owl SoCs DMA controller.

Applied, thanks

-- 
~Vinod

Re: [PATCH v3 3/4] dmaengine: Add Actions Semi Owl family S900 DMA driver

[Vinod]

On 26-07-18, 10:36, Manivannan Sadhasivam wrote:
> Add Actions Semi Owl family S900 DMA driver.

Applied, thanks

-- 
~Vinod