[RFC 3/5] media: platform: rcar_drif: Add DRIF support

[Ramesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com>]

This patch adds Digital Radio Interface (DRIF) support to R-Car Gen3 SoCs.
The driver exposes each instance of DRIF as a V4L2 SDR device. A DRIF
device represents a channel and each channel can have one or two
sub-channels respectively depending on the target board.

DRIF supports only Rx functionality. It receives samples from a RF
frontend tuner chip it is interfaced with. The combination of DRIF and the
tuner device, which is registered as a sub-device, determines the receive
sample rate and format.

In order to be compliant as a V4L2 SDR device, DRIF needs to bind with
the tuner device, which can be provided by a third party vendor. DRIF acts
as a slave device and the tuner device acts as a master transmitting the
samples. The driver allows asynchronous binding of a tuner device that
is registered as a v4l2 sub-device. The driver can learn about the tuner
it is interfaced with based on port endpoint properties of the device in
device tree. The V4L2 SDR device inherits the controls exposed by the
tuner device.

The device can also be configured to use either one or both of the data
pins at runtime based on the master (tuner) configuration.

Signed-off-by: Ramesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com>
---
 .../devicetree/bindings/media/renesas,drif.txt     |  109 ++
 drivers/media/platform/Kconfig                     |   25 +
 drivers/media/platform/Makefile                    |    1 +
 drivers/media/platform/rcar_drif.c                 | 1534 ++++++++++++++++++++
 4 files changed, 1669 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/renesas,drif.txt
 create mode 100644 drivers/media/platform/rcar_drif.c

diff --git a/Documentation/devicetree/bindings/media/renesas,drif.txt b/Documentation/devicetree/bindings/media/renesas,drif.txt
new file mode 100644
index 0000000..24239d9
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/renesas,drif.txt
@@ -0,0 +1,109 @@
+Renesas R-Car Gen3 DRIF controller (DRIF)
+-----------------------------------------
+
+Required properties:
+--------------------
+- compatible: "renesas,drif-r8a7795" if DRIF controller is a part of R8A7795 SoC.
+	      "renesas,rcar-gen3-drif" for a generic R-Car Gen3 compatible device.
+	      When compatible with the generic version, nodes must list the
+	      SoC-specific version corresponding to the platform first
+	      followed by the generic version.
+
+- reg: offset and length of each sub-channel.
+- interrupts: associated with each sub-channel.
+- clocks: phandles and clock specifiers for each sub-channel.
+- clock-names: clock input name strings: "fck0", "fck1".
+- pinctrl-0: pin control group to be used for this controller.
+- pinctrl-names: must be "default".
+- dmas: phandles to the DMA channels for each sub-channel.
+- dma-names: names for the DMA channels: "rx0", "rx1".
+
+Required child nodes:
+---------------------
+- Each DRIF channel can have one or both of the sub-channels enabled in a
+  setup. The sub-channels are represented as a child node. The name of the
+  child nodes are "sub-channel0" and "sub-channel1" respectively. Each child
+  node supports the "status" property only, which is used to enable/disable
+  the respective sub-channel.
+
+Optional properties:
+--------------------
+- port: video interface child port node of a channel that defines the local
+  and remote endpoints. The remote endpoint is assumed to a tuner subdevice
+  endpoint.
+- power-domains: phandle to respective power domain.
+- renesas,syncmd       : sync mode
+			 0 (Frame start sync pulse mode. 1-bit width pulse
+			    indicates start of a frame)
+			 1 (L/R sync or I2S mode) (default)
+- renesas,lsb-first    : empty property indicates lsb bit is received first.
+			 When not defined msb bit is received first (default)
+- renesas,syncac-pol-high  : empty property indicates sync signal polarity.
+			 When defined, active high or high->low sync signal.
+			 When not defined, active low or low->high sync signal
+			 (default)
+- renesas,dtdl         : delay between sync signal and start of reception.
+			 Must contain one of the following values:
+			 0   (no bit delay)
+			 50  (0.5-clock-cycle delay)
+			 100 (1-clock-cycle delay) (default)
+			 150 (1.5-clock-cycle delay)
+			 200 (2-clock-cycle delay)
+- renesas,syncdl       : delay between end of reception and sync signal edge.
+			 Must contain one of the following values:
+			 0   (no bit delay) (default)
+			 50  (0.5-clock-cycle delay)
+			 100 (1-clock-cycle delay)
+			 150 (1.5-clock-cycle delay)
+			 200 (2-clock-cycle delay)
+			 300 (3-clock-cycle delay)
+
+Example
+--------
+
+SoC common dtsi file
+
+drif0: rif@e6f40000 {
+	compatible = "renesas,drif-r8a7795",
+		   "renesas,rcar-gen3-drif";
+	reg = <0 0xe6f40000 0 0x64>, <0 0xe6f50000 0 0x64>;
+	interrupts = <GIC_SPI 12 IRQ_TYPE_LEVEL_HIGH>,
+		   <GIC_SPI 13 IRQ_TYPE_LEVEL_HIGH>;
+	clocks = <&cpg CPG_MOD 515>, <&cpg CPG_MOD 514>;
+	clock-names = "fck0", "fck1";
+	dmas = <&dmac1 0x20>, <&dmac1 0x22>;
+	dma-names = "rx0", "rx1";
+	power-domains = <&sysc R8A7795_PD_ALWAYS_ON>;
+	status = "disabled";
+
+	sub-channel0 {
+		status = "disabled";
+	};
+
+	sub-channel1 {
+		status = "disabled";
+	};
+
+};
+
+Board specific dts file
+
+&drif0 {
+	pinctrl-0 = <&drif0_pins>;
+	pinctrl-names = "default";
+	status = "okay";
+
+	sub-channel0 {
+		status = "okay";
+	};
+
+	sub-channel1 {
+		status = "okay";
+	};
+
+	port {
+		drif0_ep: endpoint {
+		     remote-endpoint = <&tuner_subdev_ep>;
+		};
+	};
+};
diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
index e9fc288..0ba6c1f 100644
--- a/drivers/media/platform/Kconfig
+++ b/drivers/media/platform/Kconfig
@@ -377,3 +377,28 @@ menuconfig DVB_PLATFORM_DRIVERS
 if DVB_PLATFORM_DRIVERS
 source "drivers/media/platform/sti/c8sectpfe/Kconfig"
 endif #DVB_PLATFORM_DRIVERS
+
+menuconfig SDR_PLATFORM_DRIVERS
+	bool "SDR platform devices"
+	depends on MEDIA_SDR_SUPPORT
+	default n
+	---help---
+	  Say Y here to enable support for platform-specific SDR Drivers.
+
+if SDR_PLATFORM_DRIVERS
+
+config VIDEO_RCAR_DRIF
+	tristate "Renesas Digitial Radio Interface (DRIF)"
+	depends on VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API && HAS_DMA
+	depends on ARCH_RENESAS
+	select VIDEOBUF2_VMALLOC
+	---help---
+	  Say Y if you want to enable R-Car Gen3 DRIF support. DRIF is Digital
+	  Radio Interface that interfaces with an RF front end chip. It is a
+	  receiver of digital data which uses DMA to transfer received data to
+	  a configured location for an application to use.
+
+	  To compile this driver as a module, choose M here; the module
+	  will be called rcar_drif.
+
+endif # SDR_PLATFORM_DRIVERS
diff --git a/drivers/media/platform/Makefile b/drivers/media/platform/Makefile
index 40b18d1..e3e38b4 100644
--- a/drivers/media/platform/Makefile
+++ b/drivers/media/platform/Makefile
@@ -49,6 +49,7 @@ obj-$(CONFIG_SOC_CAMERA)		+= soc_camera/
 
 obj-$(CONFIG_VIDEO_RENESAS_FCP) 	+= rcar-fcp.o
 obj-$(CONFIG_VIDEO_RENESAS_JPU) 	+= rcar_jpu.o
+obj-$(CONFIG_VIDEO_RCAR_DRIF)		+= rcar_drif.o
 obj-$(CONFIG_VIDEO_RENESAS_VSP1)	+= vsp1/
 
 obj-y	+= omap/
diff --git a/drivers/media/platform/rcar_drif.c b/drivers/media/platform/rcar_drif.c
new file mode 100644
index 0000000..39d8637
--- /dev/null
+++ b/drivers/media/platform/rcar_drif.c
@@ -0,0 +1,1534 @@
+/*
+ * R-Car Gen3 Digital Radio Interface (DRIF) driver
+ *
+ * Copyright (C) 2016 Renesas Electronics Corporation
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ */
+
+/*
+ * The R-Car DRIF is a receive only MSIOF like controller with an
+ * external master device driving the SCK. It receives data into a FIFO,
+ * then this driver uses the SYS-DMAC engine to move the data from
+ * the device to memory.
+ *
+ * Each DRIF channel supports two sub-channels with their own resources
+ * like module clk, register set and dma.
+ *
+ * Depending on the master device, a DRIF channel can use
+ *  (1) both sub-channels (D0 & D1 pins) to receive data in parallel (or)
+ *  (2) one sub-channel (D0 or D1) to receive data
+ *
+ * The primary design goal of this controller is to act as Digitial Radio
+ * Interface that receives digital samples from a tuner device. Hence the
+ * driver exposes the device as a V4L2 SDR device. In order to qualify as
+ * a V4L2 SDR device, it should possess tuner interface as mandated by the
+ * framework. This driver expects a tuner driver (sub-device) to bind
+ * asynchronously with this device and the combined drivers shall expose
+ * a V4L2 compliant SDR device. The DRIF driver is independent of the
+ * tuner vendor.
+ */
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/ioctl.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <media/v4l2-async.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-event.h>
+#include <media/v4l2-fh.h>
+#include <media/v4l2-ioctl.h>
+#include <media/videobuf2-v4l2.h>
+#include <media/videobuf2-vmalloc.h>
+
+/* Internal flags */
+#define RCAR_DRIF_BUF_DONE			BIT(0)
+#define RCAR_DRIF_BUF_OVERFLOW			BIT(1)
+
+#define RCAR_DRIF_BUF_PAIRS_DONE(buf1, buf2)	\
+	((buf1->status & buf2->status & RCAR_DRIF_BUF_DONE) == \
+	 RCAR_DRIF_BUF_DONE)
+
+/* DRIF register offsets */
+#define RCAR_DRIF_SITMDR1			(0x00)
+#define RCAR_DRIF_SITMDR2			(0x04)
+#define RCAR_DRIF_SITMDR3			(0x08)
+#define RCAR_DRIF_SIRMDR1			(0x10)
+#define RCAR_DRIF_SIRMDR2			(0x14)
+#define RCAR_DRIF_SIRMDR3			(0x18)
+#define RCAR_DRIF_SICTR				(0x28)
+#define RCAR_DRIF_SIFCTR			(0x30)
+#define RCAR_DRIF_SISTR				(0x40)
+#define RCAR_DRIF_SIIER				(0x44)
+#define RCAR_DRIF_SIRFDR			(0x60)
+
+#define RCAR_DRIF_RFOVF			BIT(3)	/* Receive FIFO overflow */
+#define RCAR_DRIF_RFUDF			BIT(4)	/* Receive FIFO underflow */
+#define RCAR_DRIF_RFSERR		BIT(5)	/* Receive frame sync error */
+#define RCAR_DRIF_REOF			BIT(7)	/* Frame reception end */
+#define RCAR_DRIF_RDREQ			BIT(12) /* Receive data xfer req */
+#define RCAR_DRIF_RFFUL			BIT(13)	/* Receive FIFO full */
+
+/* Configuration */
+#define RCAR_DRIF_SIRMDR1_SYNCMD_FRAME		(0 << 28)
+#define RCAR_DRIF_SIRMDR1_SYNCMD_LR		(3 << 28)
+
+#define RCAR_DRIF_SIRMDR1_SYNCAC_POL_HIGH	(0 << 25)
+#define RCAR_DRIF_SIRMDR1_SYNCAC_POL_LOW	(1 << 25)
+
+#define RCAR_DRIF_SIRMDR1_MSB_FIRST		(0 << 24)
+#define RCAR_DRIF_SIRMDR1_LSB_FIRST		(1 << 24)
+
+#define RCAR_DRIF_SIRMDR1_DTDL_0		(0 << 20)
+#define RCAR_DRIF_SIRMDR1_DTDL_1		(1 << 20)
+#define RCAR_DRIF_SIRMDR1_DTDL_2		(2 << 20)
+#define RCAR_DRIF_SIRMDR1_DTDL_0PT5		(5 << 20)
+#define RCAR_DRIF_SIRMDR1_DTDL_1PT5		(6 << 20)
+
+#define RCAR_DRIF_SIRMDR1_SYNCDL_0		(0 << 20)
+#define RCAR_DRIF_SIRMDR1_SYNCDL_1		(1 << 20)
+#define RCAR_DRIF_SIRMDR1_SYNCDL_2		(2 << 20)
+#define RCAR_DRIF_SIRMDR1_SYNCDL_3		(3 << 20)
+#define RCAR_DRIF_SIRMDR1_SYNCDL_0PT5		(5 << 20)
+#define RCAR_DRIF_SIRMDR1_SYNCDL_1PT5		(6 << 20)
+
+#define RCAR_DRIF_MDR_GRPCNT(n)			(((n) - 1) << 30)
+#define RCAR_DRIF_MDR_BITLEN(n)			(((n) - 1) << 24)
+#define RCAR_DRIF_MDR_WDCNT(n)			(((n) - 1) << 16)
+
+/* Hidden Transmit register that controls CLK & SYNC */
+#define RCAR_DRIF_SITMDR1_PCON			BIT(30)
+
+#define RCAR_DRIF_SICTR_RX_RISING_EDGE		BIT(26)
+#define RCAR_DRIF_SICTR_RX_EN			BIT(8)
+#define RCAR_DRIF_SICTR_RESET			BIT(0)
+
+/* Constants */
+#define RCAR_DRIF_MAX_NUM_HWBUFS		32
+#define RCAR_DRIF_MAX_DEVS			4
+#define RCAR_DRIF_DEFAULT_NUM_HWBUFS		16
+#define RCAR_DRIF_DEFAULT_HWBUF_SIZE		(4 * PAGE_SIZE)
+#define RCAR_DRIF_MAX_SUBCHANS			2
+#define RCAR_SDR_BUFFER_SIZE			(64 * 1024)
+
+/* A tuner for each sub channel */
+#define RCAR_DRIF_MAX_SUBDEVS			RCAR_DRIF_MAX_SUBCHANS
+
+/* Stream formats */
+struct rcar_drif_format {
+	char	*name;
+	u32	pixelformat;
+	u32	buffersize;
+	u32	wdlen;
+	u32	num_schans;
+};
+
+/* Format descriptions for capture and preview */
+static const struct rcar_drif_format formats[] = {
+	{
+		.name		= "Sliced Complex U16BE",
+		.pixelformat	= V4L2_SDR_FMT_SCU16BE,
+		.buffersize	= RCAR_SDR_BUFFER_SIZE,
+		.wdlen		= 16,
+		.num_schans	= 2,
+	},
+	{
+		.name		= "Sliced Complex U18BE",
+		.pixelformat	= V4L2_SDR_FMT_SCU18BE,
+		.buffersize	= RCAR_SDR_BUFFER_SIZE,
+		.wdlen		= 18,
+		.num_schans	= 2,
+	},
+	{
+		.name		= "Sliced Complex U20BE",
+		.pixelformat	= V4L2_SDR_FMT_SCU20BE,
+		.buffersize	= RCAR_SDR_BUFFER_SIZE,
+		.wdlen		= 20,
+		.num_schans	= 2,
+	},
+};
+
+#define to_rcar_drif_buf_pair(p, ch, idx)		\
+	(p->schan[!ch]->buf[idx])
+
+static const unsigned int NUM_FORMATS = ARRAY_SIZE(formats);
+
+/* Buffer for a received frame from one or both sub-channels */
+struct rcar_drif_frame_buf {
+	/* Common v4l buffer stuff -- must be first */
+	struct vb2_v4l2_buffer vb;
+	struct list_head list;
+};
+
+struct rcar_drif_async_subdev {
+	struct v4l2_subdev *sd;
+	struct v4l2_async_subdev asd;
+};
+
+/* DMA buffer */
+struct rcar_drif_hwbuf {
+	void *addr;			/* Cpu-side address */
+	int status;			/* Buffer status flags */
+};
+
+/* Sub-channel resources */
+struct rcar_drif_subchan {
+	struct rcar_drif_chan *parent;	/* Parent ctx */
+	void __iomem *base;		/* Base register address */
+	resource_size_t start;		/* I/O resource offset */
+	struct dma_chan *dmach;		/* Reserved DMA channel */
+	struct clk *clkp;		/* Module clock */
+	struct rcar_drif_hwbuf *buf[RCAR_DRIF_MAX_NUM_HWBUFS];
+	dma_addr_t dma_handle;		/* Handle for all bufs */
+	u8 num;				/* Sub-channel number */
+};
+
+/* Channel context */
+struct rcar_drif_chan {
+	struct device *dev;		/* Platform device */
+	struct video_device vdev;	/* SDR device */
+	struct v4l2_device v4l2_dev;	/* V4l2 device */
+
+	/* Videobuf2 queue and queued buffers list */
+	struct vb2_queue vb_queue;
+	struct list_head queued_bufs;
+	spinlock_t queued_bufs_lock;	/* Protects queued_bufs */
+
+	struct mutex v4l2_mutex;	/* To serialize ioctls */
+	struct mutex vb_queue_mutex;	/* To serialize streaming ioctls */
+	struct v4l2_ctrl_handler ctrl_hdl;	/* SDR control handler */
+	struct v4l2_async_notifier notifier;	/* For subdev (tuner) */
+	u32 num_subdevs;		/* Num of sub devices used */
+
+	/* Current V4L2 SDR format array index */
+	u32 fmt_idx;
+
+	/* Device tree SYNC properties */
+	u32 mdr1;
+
+	/* Internals */
+	struct rcar_drif_subchan *schan[2]; /* DRIFx0 and DRIFx1 */
+	unsigned long hw_schans_mask;	/* Enabled sub-channels per DT */
+	unsigned long cur_schans_mask;	/* Used sub-channels for an SDR FMT */
+	u32 num_hw_schans;		/* Num of DT enabled sub-channels */
+	u32 num_cur_schans;		/* Num of used sub-channels */
+	u32 num_hwbufs;			/* Num of DMA buffers */
+	u32 hwbuf_size;			/* Each DMA buffer size */
+	u32 produced;			/* Counter: Buf produced by dev */
+};
+
+/* Allocate buffer context */
+static int rcar_drif_alloc_bufctxt(struct rcar_drif_chan *ch)
+{
+	struct rcar_drif_hwbuf *bufctx;
+	u32 i, idx;
+
+	/* Alloc buf contexts for given number of sub-channels */
+	for_each_set_bit(i, &ch->cur_schans_mask, RCAR_DRIF_MAX_SUBCHANS) {
+		bufctx = kcalloc(ch->num_hwbufs, sizeof(*bufctx), GFP_KERNEL);
+		if (!bufctx)
+			return 1;
+
+		for (idx = 0; idx < ch->num_hwbufs; idx++)
+			ch->schan[i]->buf[idx] = bufctx + idx;
+	}
+	return 0;
+}
+
+/* Release buffer context */
+static void rcar_drif_release_bufctxt(struct rcar_drif_chan *ch)
+{
+	u32 i;
+
+	/* First entry of first sub channel is the bufctxt ptr always */
+	for_each_set_bit(i, &ch->cur_schans_mask, RCAR_DRIF_MAX_SUBCHANS) {
+		kfree(ch->schan[i]->buf[0]);
+		ch->schan[i]->buf[0] = NULL;
+	}
+}
+
+/* Release DMA channel */
+static void rcar_drif_release_dmachannel(struct rcar_drif_chan *ch)
+{
+	u32 i;
+
+	for_each_set_bit(i, &ch->cur_schans_mask, RCAR_DRIF_MAX_SUBCHANS)
+		if (ch->schan[i]->dmach) {
+			dma_release_channel(ch->schan[i]->dmach);
+			ch->schan[i]->dmach = NULL;
+		}
+}
+
+/* Allocate DMA channel */
+static int rcar_drif_alloc_dmachannel(struct rcar_drif_chan *ch)
+{
+	u32 i;
+	struct dma_slave_config dma_cfg;
+	int ret = -ENODEV;
+
+	for_each_set_bit(i, &ch->cur_schans_mask, RCAR_DRIF_MAX_SUBCHANS) {
+		ch->schan[i]->dmach =
+			dma_request_slave_channel(ch->dev, (i ? "rx1" : "rx0"));
+		if (!ch->schan[i]->dmach) {
+			dev_err(&ch->vdev.dev,
+				"schan%u: dma channel req failed\n", i);
+			goto dmach_error;
+		}
+
+		/* Configure slave */
+		memset(&dma_cfg, 0, sizeof(dma_cfg));
+		dma_cfg.src_addr = (phys_addr_t)(ch->schan[i]->start +
+						 RCAR_DRIF_SIRFDR);
+		dma_cfg.dst_addr = 0;
+		dma_cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+		ret = dmaengine_slave_config(ch->schan[i]->dmach, &dma_cfg);
+		if (ret) {
+			dev_err(&ch->vdev.dev,
+				"schan%u: dma slave config failed\n", i);
+			goto dmach_error;
+		}
+		dev_dbg(&ch->vdev.dev, "schan%u: dma slave configed\n", i);
+	}
+
+	return 0;
+
+dmach_error:
+	rcar_drif_release_dmachannel(ch);
+	return ret;
+}
+
+/* Release queued vb2 buffers */
+static void rcar_drif_release_queued_bufs(struct rcar_drif_chan *ch,
+					  enum vb2_buffer_state state)
+{
+	struct rcar_drif_frame_buf *fbuf, *tmp;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ch->queued_bufs_lock, flags);
+	list_for_each_entry_safe(fbuf, tmp, &ch->queued_bufs, list) {
+		list_del(&fbuf->list);
+		vb2_buffer_done(&fbuf->vb.vb2_buf, state);
+	}
+	spin_unlock_irqrestore(&ch->queued_bufs_lock, flags);
+}
+
+/* Set MDR defaults */
+static inline void rcar_drif_set_mdr1(struct rcar_drif_chan *ch)
+{
+	u32 i;
+
+	/* Set defaults for both sub-channels */
+	for_each_set_bit(i, &ch->cur_schans_mask, RCAR_DRIF_MAX_SUBCHANS) {
+		/* Refer MSIOF section in manual for this register setting */
+		writel(RCAR_DRIF_SITMDR1_PCON,
+		       ch->schan[i]->base + RCAR_DRIF_SITMDR1);
+
+		/* Setup MDR1 value */
+		writel(ch->mdr1, ch->schan[i]->base + RCAR_DRIF_SIRMDR1);
+
+		dev_dbg(&ch->vdev.dev,
+			"schan%u: SIRMDR1 = 0x%08x",
+			i, readl(ch->schan[i]->base + RCAR_DRIF_SIRMDR1));
+	}
+}
+
+/* Extract bitlen and wdcnt from given word length */
+static int rcar_drif_convert_wdlen(struct rcar_drif_chan *ch,
+				   u32 wdlen, u32 *bitlen, u32 *wdcnt)
+{
+	u32 i, nr_wds;
+
+	/* FIFO register size is 32 bits */
+	for (i = 0; i < 32; i++) {
+		nr_wds = wdlen % (32 - i);
+		if (nr_wds == 0) {
+			*bitlen = (32 - i);
+			*wdcnt = (wdlen / *bitlen);
+			break;
+		}
+	}
+
+	/* Sanity check range */
+	if ((i == 32) || !((*bitlen >= 8) && (*bitlen <= 32)) ||
+	    !((*wdcnt >= 1) && (*wdcnt <= 64))) {
+		dev_err(&ch->vdev.dev, "invalid wdlen %u configured\n",
+			wdlen);
+		return 1;
+	}
+
+	return 0;
+}
+
+/* Set DRIF receive format */
+static int rcar_drif_set_format(struct rcar_drif_chan *ch)
+{
+	u32 i, bitlen, wdcnt, wdlen;
+
+	wdlen = formats[ch->fmt_idx].wdlen;
+	dev_dbg(&ch->vdev.dev, "setfmt: idx %u, wdlen %u, num_schans %u\n",
+		ch->fmt_idx, wdlen, formats[ch->fmt_idx].num_schans);
+
+	/* Sanity check */
+	if (formats[ch->fmt_idx].num_schans > ch->num_cur_schans) {
+		dev_err(ch->dev, "fmt idx %u current schans %u mismatch\n",
+			ch->fmt_idx, ch->num_cur_schans);
+		return 1;
+	}
+
+	if (rcar_drif_convert_wdlen(ch, wdlen, &bitlen, &wdcnt))
+		return 1;
+
+	/* Setup group, bitlen & word count */
+	for_each_set_bit(i, &ch->cur_schans_mask, RCAR_DRIF_MAX_SUBCHANS) {
+		u32 mdr;
+
+		/* Two groups */
+		mdr = RCAR_DRIF_MDR_GRPCNT(2) | RCAR_DRIF_MDR_BITLEN(bitlen) |
+		       RCAR_DRIF_MDR_WDCNT(wdcnt);
+		writel(mdr, ch->schan[i]->base + RCAR_DRIF_SIRMDR2);
+
+		mdr = RCAR_DRIF_MDR_BITLEN(bitlen) | RCAR_DRIF_MDR_WDCNT(wdcnt);
+		writel(mdr, ch->schan[i]->base + RCAR_DRIF_SIRMDR3);
+
+		dev_dbg(&ch->vdev.dev,
+			"schan%u: new SIRMDR[2,3] = 0x%08x 0x%08x\n",
+			i, readl(ch->schan[i]->base + RCAR_DRIF_SIRMDR2),
+			readl(ch->schan[i]->base + RCAR_DRIF_SIRMDR3));
+	}
+	return 0;
+}
+
+/* Release DMA buffers */
+static void rcar_drif_release_buf(struct rcar_drif_chan *ch)
+{
+	u32 i;
+
+	for_each_set_bit(i, &ch->cur_schans_mask, RCAR_DRIF_MAX_SUBCHANS) {
+		struct rcar_drif_subchan *schan = ch->schan[i];
+
+		/* First entry of the sub-channel contains the dma buf ptr */
+		if (schan->buf[0] && schan->buf[0]->addr) {
+			dma_free_coherent(ch->dev,
+				ch->hwbuf_size * ch->num_hwbufs,
+				schan->buf[0]->addr, schan->dma_handle);
+			schan->buf[0]->addr = NULL;
+		}
+	}
+}
+
+/* Request DMA buffers */
+static int rcar_drif_request_buf(struct rcar_drif_chan *ch)
+{
+	int ret = 0;
+	u32 i, j;
+	void *addr;
+
+	for_each_set_bit(i, &ch->cur_schans_mask, RCAR_DRIF_MAX_SUBCHANS) {
+		struct rcar_drif_subchan *schan = ch->schan[i];
+
+		/* Allocate DMA buffers */
+		addr = dma_alloc_coherent(ch->dev,
+				ch->hwbuf_size * ch->num_hwbufs,
+				&schan->dma_handle, GFP_KERNEL);
+		if (!addr) {
+			dev_err(&ch->vdev.dev,
+				"dma alloc failed. num_hwbufs %u hwbuf_size %u\n",
+				ch->num_hwbufs, ch->hwbuf_size);
+			ret = 1;
+			goto alloc_error;
+		}
+
+		for (j = 0; j < ch->num_hwbufs; j++) {
+			schan->buf[j]->addr = addr + (j * ch->hwbuf_size);
+			schan->buf[j]->status = 0;
+		}
+	}
+
+	return 0;
+
+alloc_error:
+	return ret;
+}
+
+/* Setup vb_queue minimum buffer requirements */
+static int rcar_drif_queue_setup(struct vb2_queue *vq,
+			unsigned int *num_buffers, unsigned int *num_planes,
+			unsigned int sizes[], struct device *alloc_devs[])
+{
+	struct rcar_drif_chan *ch = vb2_get_drv_priv(vq);
+
+	dev_dbg(&ch->vdev.dev, "num_buffers %u vq->num_buffers %u\n",
+		*num_buffers, vq->num_buffers);
+
+	/* Need at least 16 buffers */
+	if (vq->num_buffers + *num_buffers < 16)
+		*num_buffers = 16 - vq->num_buffers;
+
+	*num_planes = 1;
+	sizes[0] = PAGE_ALIGN(formats[ch->fmt_idx].buffersize);
+
+	dev_dbg(&ch->vdev.dev, "nbuf %d sizes[0] %d\n", *num_buffers, sizes[0]);
+	return 0;
+}
+
+/* Enqueue buffer */
+static void rcar_drif_buf_queue(struct vb2_buffer *vb)
+{
+	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+	struct rcar_drif_chan *ch = vb2_get_drv_priv(vb->vb2_queue);
+	struct rcar_drif_frame_buf *fbuf =
+			container_of(vbuf, struct rcar_drif_frame_buf, vb);
+	unsigned long flags;
+
+	dev_dbg(&ch->vdev.dev, "buf_queue idx %u len %u, used %d\n", vb->index,
+		vb->planes[0].length, vb->planes[0].bytesused);
+	spin_lock_irqsave(&ch->queued_bufs_lock, flags);
+	list_add_tail(&fbuf->list, &ch->queued_bufs);
+	spin_unlock_irqrestore(&ch->queued_bufs_lock, flags);
+}
+
+/* Deliver buffer to user space */
+static void rcar_drif_deliver_buf(struct rcar_drif_subchan *schan, u32 idx)
+{
+	struct rcar_drif_chan *ch = schan->parent;
+	struct rcar_drif_frame_buf *fbuf;
+	unsigned long flags;
+	bool overflow = false;
+
+	spin_lock_irqsave(&ch->queued_bufs_lock, flags);
+	fbuf = list_first_entry_or_null(&ch->queued_bufs, struct
+					rcar_drif_frame_buf, list);
+	if (!fbuf) {
+		/* App is late in enqueing buffers. There will be a gap in
+		 * sequence number when app recovers
+		 */
+		dev_dbg(&ch->vdev.dev, "app late: schan%u: prod %u\n",
+			schan->num, ch->produced);
+		ch->produced++;	/* Increment the produced count anyway */
+		spin_unlock_irqrestore(&ch->queued_bufs_lock, flags);
+		return;
+	}
+	list_del(&fbuf->list);
+	spin_unlock_irqrestore(&ch->queued_bufs_lock, flags);
+
+	if (ch->num_cur_schans == RCAR_DRIF_MAX_SUBCHANS) {
+		struct rcar_drif_hwbuf *buf_i, *buf_q;
+
+		if (schan->num) {
+			buf_i = to_rcar_drif_buf_pair(ch, schan->num, idx);
+			buf_q = schan->buf[idx];
+		} else {
+			buf_q = to_rcar_drif_buf_pair(ch, schan->num, idx);
+			buf_i = schan->buf[idx];
+		}
+		memcpy(vb2_plane_vaddr(&fbuf->vb.vb2_buf, 0),
+		       buf_i->addr, ch->hwbuf_size);
+		memcpy(vb2_plane_vaddr(&fbuf->vb.vb2_buf, 0) + ch->hwbuf_size,
+		       buf_q->addr, ch->hwbuf_size);
+
+		if ((buf_i->status | buf_q->status) & RCAR_DRIF_BUF_OVERFLOW) {
+			/* Clear the flag in status */
+			buf_i->status &= ~RCAR_DRIF_BUF_OVERFLOW;
+			buf_q->status &= ~RCAR_DRIF_BUF_OVERFLOW;
+			overflow = true;
+		}
+	} else {
+		struct rcar_drif_hwbuf *buf_iq;
+
+		buf_iq = schan->buf[idx];
+		memcpy(vb2_plane_vaddr(&fbuf->vb.vb2_buf, 0),
+		       buf_iq->addr, ch->hwbuf_size);
+
+		if (buf_iq->status & RCAR_DRIF_BUF_OVERFLOW) {
+			/* Clear the flag in status */
+			buf_iq->status &= ~RCAR_DRIF_BUF_OVERFLOW;
+			overflow = true;
+		}
+	}
+
+	dev_dbg(&ch->vdev.dev, "schan%u: produced %u\n",
+		schan->num, ch->produced);
+
+	fbuf->vb.field = V4L2_FIELD_NONE;
+	fbuf->vb.sequence = ch->produced++;
+	fbuf->vb.vb2_buf.timestamp = ktime_get_ns();
+	vb2_set_plane_payload(&fbuf->vb.vb2_buf, 0,
+			      formats[ch->fmt_idx].buffersize);
+	if (overflow)
+		vb2_buffer_done(&fbuf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
+	else
+		vb2_buffer_done(&fbuf->vb.vb2_buf, VB2_BUF_STATE_DONE);
+}
+
+/* Check if DMA of the paired sub-channel is also complete */
+static void rcar_drif_dmapair_complete(struct rcar_drif_subchan *schan, u32 idx)
+{
+	struct rcar_drif_chan *ch = schan->parent;
+	struct rcar_drif_hwbuf *buf, *pair;
+
+	buf = schan->buf[idx];
+	pair = to_rcar_drif_buf_pair(ch, schan->num, idx);
+	buf->status |= RCAR_DRIF_BUF_DONE;
+	dev_dbg(&ch->vdev.dev, "schan%u: status: buf 0x%08x pair 0x%08x\n",
+		schan->num, buf->status, pair->status);
+
+	/* Check if both DMA buffers are done */
+	if (RCAR_DRIF_BUF_PAIRS_DONE(buf, pair)) {
+		/* Clear status flag */
+		buf->status &= ~RCAR_DRIF_BUF_DONE;
+		pair->status &= ~RCAR_DRIF_BUF_DONE;
+
+		/* Deliver buffer to user */
+		rcar_drif_deliver_buf(schan, idx);
+	}
+}
+
+/* DMA callback for each stage */
+static void rcar_drif_dma_complete(void *dma_async_param)
+{
+	struct rcar_drif_subchan *schan =
+		(struct rcar_drif_subchan *)dma_async_param;
+	struct rcar_drif_chan *ch = schan->parent;
+	struct rcar_drif_hwbuf *buf;
+	u32 str, idx;
+
+	mutex_lock(&ch->vb_queue_mutex);
+
+	/* DMA can be terminated while the callback was waiting on lock */
+	if (!vb2_is_streaming(&ch->vb_queue)) {
+		mutex_unlock(&ch->vb_queue_mutex);
+		return;
+	}
+
+	idx = ch->produced % ch->num_hwbufs;
+	buf = schan->buf[idx];
+
+	/* Check for DRIF errors */
+	str = readl(schan->base + RCAR_DRIF_SISTR);
+	if (str & RCAR_DRIF_RFOVF) {
+		/* Writing the same clears it */
+		writel(str, schan->base + RCAR_DRIF_SISTR);
+
+		/* Overflow: some samples are lost */
+		buf->status |= RCAR_DRIF_BUF_OVERFLOW;
+		dev_dbg(&ch->vdev.dev, "fifo overflow: schan%u: prod %d\n",
+			schan->num, ch->produced);
+	}
+
+	/* Check if the rx'ed data can be delivered to user */
+	if (ch->num_cur_schans == RCAR_DRIF_MAX_SUBCHANS)
+		rcar_drif_dmapair_complete(schan, idx);
+	else
+		rcar_drif_deliver_buf(schan, idx);
+
+	mutex_unlock(&ch->vb_queue_mutex);
+}
+
+static int rcar_drif_qbuf(struct rcar_drif_subchan *schan)
+{
+	struct rcar_drif_chan *ch = schan->parent;
+	dma_addr_t addr = schan->dma_handle;
+	struct dma_async_tx_descriptor *rxd;
+	dma_cookie_t cookie;
+
+	/* Setup cyclic DMA with given buffers */
+	rxd = dmaengine_prep_dma_cyclic(schan->dmach, addr,
+					ch->hwbuf_size * ch->num_hwbufs,
+					ch->hwbuf_size, DMA_DEV_TO_MEM,
+					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!rxd) {
+		dev_err(&ch->vdev.dev, "schan%u: prep dma cyclic failed\n",
+			schan->num);
+		return 1;
+	}
+
+	/* Submit descriptor */
+	rxd->callback = rcar_drif_dma_complete;
+	rxd->callback_param = schan;
+	dev_dbg(&ch->vdev.dev, "schan%u: param %p\n", schan->num, schan);
+	cookie = dmaengine_submit(rxd);
+	if (dma_submit_error(cookie)) {
+		dev_err(&ch->vdev.dev, "schan%u: dma submit failed\n",
+			schan->num);
+		return 1;
+	}
+
+	dma_async_issue_pending(schan->dmach);
+	return 0;
+}
+
+/* Enable reception */
+static int rcar_drif_enable_rx(struct rcar_drif_chan *ch)
+{
+	u32 ctr, i;
+	int ret;
+
+	/*
+	 * When both sub-channels are enabled, they can be syncronized only by
+	 * the master
+	 */
+
+	/* Enable receive */
+	for_each_set_bit(i, &ch->cur_schans_mask, RCAR_DRIF_MAX_SUBCHANS) {
+		ctr = readl(ch->schan[i]->base + RCAR_DRIF_SICTR);
+		ctr |= (RCAR_DRIF_SICTR_RX_RISING_EDGE |
+			 RCAR_DRIF_SICTR_RX_EN);
+		writel(ctr, ch->schan[i]->base + RCAR_DRIF_SICTR);
+	}
+
+	/* Check receive enabled */
+	for_each_set_bit(i, &ch->cur_schans_mask, RCAR_DRIF_MAX_SUBCHANS) {
+		ret = readl_poll_timeout(ch->schan[i]->base + RCAR_DRIF_SICTR,
+					 ctr, ctr & RCAR_DRIF_SICTR_RX_EN,
+					 2, 500000);
+		if (ret) {
+			dev_err(&ch->vdev.dev,
+			"schan%u: failed to enable rx. CTR 0x%08x\n",
+			i, readl(ch->schan[i]->base + RCAR_DRIF_SICTR));
+			break;
+		}
+	}
+	return ret;
+}
+
+/* Disable reception */
+static void rcar_drif_disable_rx(struct rcar_drif_chan *ch)
+{
+	u32 ctr, i;
+	int ret;
+
+	/* Disable receive */
+	for_each_set_bit(i, &ch->cur_schans_mask, RCAR_DRIF_MAX_SUBCHANS) {
+		ctr = readl(ch->schan[i]->base + RCAR_DRIF_SICTR);
+		ctr &= ~RCAR_DRIF_SICTR_RX_EN;
+		writel(ctr, ch->schan[i]->base + RCAR_DRIF_SICTR);
+	}
+
+	/* Check receive disabled */
+	for_each_set_bit(i, &ch->cur_schans_mask, RCAR_DRIF_MAX_SUBCHANS) {
+		ret = readl_poll_timeout(ch->schan[i]->base + RCAR_DRIF_SICTR,
+					 ctr, !(ctr & RCAR_DRIF_SICTR_RX_EN),
+					 2, 500000);
+		if (ret)
+			dev_warn(&ch->vdev.dev,
+			"schan%u: failed to disable rx. CTR 0x%08x\n",
+			i, readl(ch->schan[i]->base + RCAR_DRIF_SICTR));
+	}
+}
+
+/* Start sub-channel */
+static int rcar_drif_start_subchan(struct rcar_drif_subchan *schan)
+{
+	struct rcar_drif_chan *ch = schan->parent;
+	u32 ctr, str;
+	int ret;
+
+	/* Reset receive */
+	writel(RCAR_DRIF_SICTR_RESET, schan->base + RCAR_DRIF_SICTR);
+	ret = readl_poll_timeout(schan->base + RCAR_DRIF_SICTR,
+					 ctr, !(ctr & RCAR_DRIF_SICTR_RESET),
+					 2, 500000);
+	if (ret) {
+		dev_err(&ch->vdev.dev,
+			"schan%u: failed to reset rx. CTR 0x%08x\n",
+			schan->num, readl(schan->base + RCAR_DRIF_SICTR));
+		return ret;
+	}
+
+	/* Queue buffers for DMA */
+	if (rcar_drif_qbuf(schan)) {
+		dev_err(&ch->vdev.dev,
+			"failed to queue schan %u DMA transfer.\n", schan->num);
+		return 1;
+	}
+
+	/* Clear status register flags */
+	str = RCAR_DRIF_RFFUL | RCAR_DRIF_REOF | RCAR_DRIF_RFSERR |
+		RCAR_DRIF_RFUDF | RCAR_DRIF_RFOVF;
+	writel(str, schan->base + RCAR_DRIF_SISTR);
+
+	/* Enable DMA receive interrupt */
+	writel(0x00009000, schan->base + RCAR_DRIF_SIIER);
+
+	return 0;
+}
+
+/* Start receive operation */
+static int rcar_drif_start(struct rcar_drif_chan *ch)
+{
+	u32 i;
+	int ret;
+
+	for_each_set_bit(i, &ch->cur_schans_mask, RCAR_DRIF_MAX_SUBCHANS) {
+		ret = rcar_drif_start_subchan(ch->schan[i]);
+		if (ret)
+			goto start_error;
+	}
+
+	/* Reset counters */
+	ch->produced = 0;
+
+	/* Enable Rx */
+	ret = rcar_drif_enable_rx(ch);
+	if (ret)
+		goto start_error;
+
+	dev_dbg(&ch->vdev.dev, "started\n");
+
+start_error:
+	return ret;
+}
+
+/* Stop sub-channel */
+static void rcar_drif_stop_subchan(struct rcar_drif_subchan *schan)
+{
+	struct rcar_drif_chan *ch = schan->parent;
+	int ret, retries = 3;
+
+	/* Disable DMA receive interrupt */
+	writel(0x00000000, schan->base + RCAR_DRIF_SIIER);
+
+	do {
+		/* Terminate all DMA transfers */
+		ret = dmaengine_terminate_sync(schan->dmach);
+		if (!ret)
+			break;
+		dev_dbg(&ch->vdev.dev, "stop retry\n");
+	} while (--retries);
+
+	WARN_ON(!retries);
+}
+
+/* Stop receive operation */
+static void rcar_drif_stop(struct rcar_drif_chan *ch)
+{
+	u32 i;
+
+	/* Disable Rx */
+	rcar_drif_disable_rx(ch);
+
+	for_each_set_bit(i, &ch->cur_schans_mask, RCAR_DRIF_MAX_SUBCHANS)
+		rcar_drif_stop_subchan(ch->schan[i]);
+
+	dev_dbg(&ch->vdev.dev, "stopped: prod %u\n", ch->produced);
+}
+
+/* Start streaming */
+static int rcar_drif_start_streaming(struct vb2_queue *vq, unsigned int count)
+{
+	struct rcar_drif_chan *ch = vb2_get_drv_priv(vq);
+	int ret, i, j;
+
+	dev_dbg(&ch->vdev.dev, "start streaming\n");
+	mutex_lock(&ch->v4l2_mutex);
+
+	for_each_set_bit(i, &ch->cur_schans_mask, RCAR_DRIF_MAX_SUBCHANS) {
+		ret = clk_prepare_enable(ch->schan[i]->clkp);
+		if (ret)
+			goto start_error;
+	}
+
+	/* Set default MDRx settings */
+	rcar_drif_set_mdr1(ch);
+
+	/* Set new format */
+	ret = rcar_drif_set_format(ch);
+	if (ret)
+		goto start_error;
+
+	if (ch->num_cur_schans == RCAR_DRIF_MAX_SUBCHANS)
+		ch->hwbuf_size = formats[ch->fmt_idx].buffersize/2;
+	else
+		ch->hwbuf_size = formats[ch->fmt_idx].buffersize;
+
+	dev_dbg(&ch->vdev.dev, "num_hwbufs %u, hwbuf_size %u\n",
+		ch->num_hwbufs, ch->hwbuf_size);
+
+	if (rcar_drif_alloc_dmachannel(ch)) {
+		ret = -ENODEV;
+		goto start_error;
+	}
+
+	/* Alloc buf context */
+	if (rcar_drif_alloc_bufctxt(ch)) {
+		ret = -ENOMEM;
+		goto start_error;
+	}
+
+	if (rcar_drif_request_buf(ch)) {
+		ret = -ENOMEM;
+		goto start_error;
+	}
+
+	dev_dbg(&ch->vdev.dev, "dma setup successful\n");
+
+	ret = rcar_drif_start(ch);
+	if (ret)
+		goto start_error;
+
+	mutex_unlock(&ch->v4l2_mutex);
+	return ret;
+
+start_error:
+	/* Return all queued buffers to vb2 */
+	rcar_drif_release_queued_bufs(ch, VB2_BUF_STATE_QUEUED);
+	rcar_drif_release_buf(ch);
+	rcar_drif_release_bufctxt(ch);
+	rcar_drif_release_dmachannel(ch);
+	for (j = 0; j < i; j++)
+		clk_disable_unprepare(ch->schan[j]->clkp);
+
+	mutex_unlock(&ch->v4l2_mutex);
+	return ret;
+}
+
+/* Stop streaming */
+static void rcar_drif_stop_streaming(struct vb2_queue *vq)
+{
+	struct rcar_drif_chan *ch = vb2_get_drv_priv(vq);
+	u32 i;
+
+	mutex_lock(&ch->v4l2_mutex);
+
+	/* Stop hardware streaming */
+	rcar_drif_stop(ch);
+
+	/* Return all queued buffers to vb2 */
+	rcar_drif_release_queued_bufs(ch, VB2_BUF_STATE_ERROR);
+
+	/* Release buf & buf context */
+	rcar_drif_release_buf(ch);
+	rcar_drif_release_bufctxt(ch);
+
+	/* Release DMA channel resources */
+	rcar_drif_release_dmachannel(ch);
+
+	for (i = 0; i < RCAR_DRIF_MAX_SUBCHANS; i++)
+		clk_disable_unprepare(ch->schan[i]->clkp);
+
+	mutex_unlock(&ch->v4l2_mutex);
+	dev_dbg(&ch->vdev.dev, "stopped streaming\n");
+}
+
+/* Vb2 ops */
+static struct vb2_ops rcar_drif_vb2_ops = {
+	.queue_setup            = rcar_drif_queue_setup,
+	.buf_queue              = rcar_drif_buf_queue,
+	.start_streaming        = rcar_drif_start_streaming,
+	.stop_streaming         = rcar_drif_stop_streaming,
+	.wait_prepare		= vb2_ops_wait_prepare,
+	.wait_finish		= vb2_ops_wait_finish,
+};
+
+static int rcar_drif_querycap(struct file *file, void *fh,
+		struct v4l2_capability *cap)
+{
+	struct rcar_drif_chan *ch = video_drvdata(file);
+
+	strlcpy(cap->driver, KBUILD_MODNAME, sizeof(cap->driver));
+	strlcpy(cap->card, ch->vdev.name, sizeof(cap->card));
+	cap->device_caps = V4L2_CAP_SDR_CAPTURE | V4L2_CAP_TUNER |
+				   V4L2_CAP_STREAMING | V4L2_CAP_READWRITE;
+	cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
+	snprintf(cap->bus_info, sizeof(cap->bus_info), "platform:%s",
+		 ch->vdev.name);
+	return 0;
+}
+
+static int rcar_drif_set_default_format(struct rcar_drif_chan *ch)
+{
+	u32 i;
+
+	for (i = 0; i < NUM_FORMATS; i++) {
+		/* Find any matching fmt and set it as default */
+		if (ch->num_hw_schans == formats[i].num_schans) {
+			ch->fmt_idx = i;
+			ch->cur_schans_mask = ch->hw_schans_mask;
+			ch->num_cur_schans = ch->num_hw_schans;
+			dev_dbg(ch->dev, "default fmt[%u]: mask %lu num %u\n",
+				i, ch->cur_schans_mask, ch->num_cur_schans);
+			return 0;
+		}
+	}
+	return -EINVAL;
+}
+
+static int rcar_drif_enum_fmt_sdr_cap(struct file *file, void *priv,
+				      struct v4l2_fmtdesc *f)
+{
+	if (f->index >= NUM_FORMATS)
+		return -EINVAL;
+
+	strlcpy(f->description, formats[f->index].name, sizeof(f->description));
+	f->pixelformat = formats[f->index].pixelformat;
+	return 0;
+}
+
+static int rcar_drif_g_fmt_sdr_cap(struct file *file, void *priv,
+				   struct v4l2_format *f)
+{
+	struct rcar_drif_chan *ch = video_drvdata(file);
+
+	f->fmt.sdr.pixelformat = formats[ch->fmt_idx].pixelformat;
+	f->fmt.sdr.buffersize = formats[ch->fmt_idx].buffersize;
+	memset(f->fmt.sdr.reserved, 0, sizeof(f->fmt.sdr.reserved));
+	return 0;
+}
+
+static int rcar_drif_s_fmt_sdr_cap(struct file *file, void *priv,
+				   struct v4l2_format *f)
+{
+	struct rcar_drif_chan *ch = video_drvdata(file);
+	struct vb2_queue *q = &ch->vb_queue;
+	u32 i;
+
+	if (vb2_is_busy(q))
+		return -EBUSY;
+
+	memset(f->fmt.sdr.reserved, 0, sizeof(f->fmt.sdr.reserved));
+	for (i = 0; i < NUM_FORMATS; i++) {
+		if (formats[i].pixelformat == f->fmt.sdr.pixelformat) {
+			ch->fmt_idx  = i;
+			f->fmt.sdr.buffersize = formats[i].buffersize;
+
+			/* If a format demands one subch out of two enabled
+			 * sub-channels then pick the 0th sub-channel
+			 */
+			if (formats[i].num_schans < ch->num_hw_schans) {
+				ch->cur_schans_mask = BIT(0);	/* Enable D0 */
+				ch->num_cur_schans = formats[i].num_schans;
+			} else {
+				ch->cur_schans_mask = ch->hw_schans_mask;
+				ch->num_cur_schans = ch->num_hw_schans;
+			}
+
+			dev_dbg(&ch->vdev.dev, "cur: idx %u mask %lu num %u\n",
+				i, ch->cur_schans_mask, ch->num_cur_schans);
+			return 0;
+		}
+	}
+
+	if (rcar_drif_set_default_format(ch))
+		return -EINVAL;
+
+	f->fmt.sdr.pixelformat = formats[ch->fmt_idx].pixelformat;
+	f->fmt.sdr.buffersize = formats[ch->fmt_idx].buffersize;
+	return 0;
+}
+
+static int rcar_drif_try_fmt_sdr_cap(struct file *file, void *priv,
+				     struct v4l2_format *f)
+{
+	struct rcar_drif_chan *ch = video_drvdata(file);
+	u32 i;
+
+	memset(f->fmt.sdr.reserved, 0, sizeof(f->fmt.sdr.reserved));
+	for (i = 0; i < NUM_FORMATS; i++) {
+		if (formats[i].pixelformat == f->fmt.sdr.pixelformat) {
+			f->fmt.sdr.buffersize = formats[i].buffersize;
+			return 0;
+		}
+	}
+
+	f->fmt.sdr.pixelformat = formats[ch->fmt_idx].pixelformat;
+	f->fmt.sdr.buffersize = formats[ch->fmt_idx].buffersize;
+	return 0;
+}
+
+static int rcar_drif_enum_freq_bands(struct file *file, void *priv,
+		struct v4l2_frequency_band *band)
+{
+	struct rcar_drif_chan *ch = video_drvdata(file);
+	struct v4l2_subdev *sd, *tmp;
+	int ret = 0;
+
+	list_for_each_entry_safe(sd, tmp, &ch->v4l2_dev.subdevs, list)
+		ret = v4l2_subdev_call(sd, tuner, enum_freq_bands, band);
+
+	return ret;
+}
+
+static int rcar_drif_g_frequency(struct file *file, void *priv,
+		struct v4l2_frequency *f)
+{
+	struct rcar_drif_chan *ch = video_drvdata(file);
+	struct v4l2_subdev *sd, *tmp;
+	int ret = 0;
+
+	list_for_each_entry_safe(sd, tmp, &ch->v4l2_dev.subdevs, list)
+		ret = v4l2_subdev_call(sd, tuner, g_frequency, f);
+
+	return ret;
+}
+
+static int rcar_drif_s_frequency(struct file *file, void *priv,
+				 const struct v4l2_frequency *f)
+{
+	struct rcar_drif_chan *ch = video_drvdata(file);
+	struct v4l2_subdev *sd, *tmp;
+	int ret = 0;
+
+	list_for_each_entry_safe(sd, tmp, &ch->v4l2_dev.subdevs, list)
+		ret = v4l2_subdev_call(sd, tuner, s_frequency, f);
+
+	return ret;
+}
+
+static int rcar_drif_g_tuner(struct file *file, void *priv,
+			     struct v4l2_tuner *vt)
+{
+	struct rcar_drif_chan *ch = video_drvdata(file);
+	struct v4l2_subdev *sd, *tmp;
+	int ret = 0;
+
+	list_for_each_entry_safe(sd, tmp, &ch->v4l2_dev.subdevs, list)
+		ret = v4l2_subdev_call(sd, tuner, g_tuner, vt);
+
+	return ret;
+}
+
+static int rcar_drif_s_tuner(struct file *file, void *priv,
+			     const struct v4l2_tuner *vt)
+{
+	struct rcar_drif_chan *ch = video_drvdata(file);
+	struct v4l2_subdev *sd, *tmp;
+	int ret = 0;
+
+	list_for_each_entry_safe(sd, tmp, &ch->v4l2_dev.subdevs, list)
+		ret = v4l2_subdev_call(sd, tuner, s_tuner, vt);
+
+	return ret;
+}
+
+static const struct v4l2_ioctl_ops rcar_drif_ioctl_ops = {
+	.vidioc_querycap          = rcar_drif_querycap,
+
+	.vidioc_enum_fmt_sdr_cap  = rcar_drif_enum_fmt_sdr_cap,
+	.vidioc_g_fmt_sdr_cap     = rcar_drif_g_fmt_sdr_cap,
+	.vidioc_s_fmt_sdr_cap     = rcar_drif_s_fmt_sdr_cap,
+	.vidioc_try_fmt_sdr_cap   = rcar_drif_try_fmt_sdr_cap,
+
+	.vidioc_reqbufs           = vb2_ioctl_reqbufs,
+	.vidioc_create_bufs       = vb2_ioctl_create_bufs,
+	.vidioc_prepare_buf       = vb2_ioctl_prepare_buf,
+	.vidioc_querybuf          = vb2_ioctl_querybuf,
+	.vidioc_qbuf              = vb2_ioctl_qbuf,
+	.vidioc_dqbuf             = vb2_ioctl_dqbuf,
+
+	.vidioc_streamon          = vb2_ioctl_streamon,
+	.vidioc_streamoff         = vb2_ioctl_streamoff,
+
+	.vidioc_s_frequency       = rcar_drif_s_frequency,
+	.vidioc_g_frequency       = rcar_drif_g_frequency,
+	.vidioc_s_tuner		  = rcar_drif_s_tuner,
+	.vidioc_g_tuner		  = rcar_drif_g_tuner,
+	.vidioc_enum_freq_bands   = rcar_drif_enum_freq_bands,
+	.vidioc_subscribe_event   = v4l2_ctrl_subscribe_event,
+	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
+	.vidioc_log_status        = v4l2_ctrl_log_status,
+};
+
+static const struct v4l2_file_operations rcar_drif_fops = {
+	.owner                    = THIS_MODULE,
+	.open                     = v4l2_fh_open,
+	.release                  = vb2_fop_release,
+	.read                     = vb2_fop_read,
+	.poll                     = vb2_fop_poll,
+	.mmap                     = vb2_fop_mmap,
+	.unlocked_ioctl           = video_ioctl2,
+};
+
+static struct video_device rcar_drif_template = {
+	.name                     = "R-Car DRIF",
+	.release                  = video_device_release_empty,
+	.fops                     = &rcar_drif_fops,
+	.ioctl_ops                = &rcar_drif_ioctl_ops,
+};
+
+static void rcar_drif_video_release(struct v4l2_device *v)
+{
+	struct rcar_drif_chan *ch = container_of(v, struct rcar_drif_chan,
+						v4l2_dev);
+	u32 i;
+
+	dev_dbg(ch->dev, "video release\n");
+	v4l2_device_unregister(&ch->v4l2_dev);
+	for_each_set_bit(i, &ch->hw_schans_mask, RCAR_DRIF_MAX_SUBCHANS)
+		kfree(ch->schan[i]);
+	kfree(ch);
+}
+
+static int rcar_drif_notify_bound(struct v4l2_async_notifier *notifier,
+				   struct v4l2_subdev *subdev,
+				   struct v4l2_async_subdev *asd)
+{
+	struct rcar_drif_chan *ch =
+		container_of(notifier, struct rcar_drif_chan, notifier);
+	dev_dbg(ch->dev, "bound: asd %s\n", asd->match.of.node->name);
+	return 0;
+}
+
+/* Sub-device registered notification callback */
+static int rcar_drif_notify_complete(struct v4l2_async_notifier *notifier)
+{
+	struct rcar_drif_chan *ch =
+		container_of(notifier, struct rcar_drif_chan, notifier);
+	struct v4l2_subdev *sd, *tmp;
+	int ret;
+
+	v4l2_ctrl_handler_init(&ch->ctrl_hdl, 10);
+	ch->v4l2_dev.ctrl_handler = &ch->ctrl_hdl;
+	dev_dbg(ch->dev, "notify complete\n");
+	ret = v4l2_device_register_subdev_nodes(&ch->v4l2_dev);
+	if (ret) {
+		dev_err(ch->dev, "failed register subdev nodes ret %d\n", ret);
+		return ret;
+	}
+
+	list_for_each_entry_safe(sd, tmp, &ch->v4l2_dev.subdevs, list) {
+		ret = v4l2_ctrl_add_handler(ch->v4l2_dev.ctrl_handler,
+					    sd->ctrl_handler, NULL);
+		if (ret) {
+			dev_err(ch->dev, "failed ctrl add hdlr ret %d\n", ret);
+			return ret;
+		}
+	}
+	return 0;
+}
+
+/* Parse sub-devs (tuner) to find a matching device */
+static int rcar_drif_parse_subdevs(struct device *dev,
+				   struct v4l2_async_notifier *notifier)
+{
+	struct device_node *node = NULL;
+
+	notifier->subdevs = devm_kcalloc(dev, RCAR_DRIF_MAX_SUBDEVS,
+				sizeof(*notifier->subdevs), GFP_KERNEL);
+	if (!notifier->subdevs)
+		return -ENOMEM;
+
+	while (notifier->num_subdevs < RCAR_DRIF_MAX_SUBDEVS &&
+	       (node = of_graph_get_next_endpoint(dev->of_node, node))) {
+		struct rcar_drif_async_subdev *rsd;
+
+		dev_dbg(dev, "node name %s\n", node->name);
+		rsd = devm_kzalloc(dev, sizeof(*rsd), GFP_KERNEL);
+		if (!rsd) {
+			of_node_put(node);
+			return -ENOMEM;
+		}
+
+		notifier->subdevs[notifier->num_subdevs] = &rsd->asd;
+		rsd->asd.match.of.node = of_graph_get_remote_port_parent(node);
+		of_node_put(node);
+		if (!rsd->asd.match.of.node) {
+			dev_warn(dev, "bad remote port parent\n");
+			return -EINVAL;
+		}
+
+		rsd->asd.match_type = V4L2_ASYNC_MATCH_OF;
+		notifier->num_subdevs++;
+	}
+	return 0;
+}
+
+/* SIRMDR1 configuration */
+static void rcar_drif_validate_syncmd(struct rcar_drif_chan *ch, u32 val)
+{
+	if (val > 1) {
+		dev_warn(ch->dev, "invalid syncmd %u using L/R mode\n", val);
+		return;
+	}
+
+	ch->mdr1 &= ~(3 << 28);	/* Clear current settings */
+	if (val == 0)
+		ch->mdr1 |= RCAR_DRIF_SIRMDR1_SYNCMD_FRAME;
+	else
+		ch->mdr1 |= RCAR_DRIF_SIRMDR1_SYNCMD_LR;
+}
+
+/* Get the dtdl or syncdl bits as in MSIOF */
+static u32 rcar_drif_get_dtdl_or_syncdl_bits(u32 dtdl_or_syncdl)
+{
+	/*
+	 * DTDL/SYNCDL bit	: dtdl/syncdl
+	 * b'000		: 0
+	 * b'001		: 100
+	 * b'010		: 200
+	 * b'011 (SYNCDL only)	: 300
+	 * b'101		: 50
+	 * b'110		: 150
+	 */
+	if (dtdl_or_syncdl % 100)
+		return dtdl_or_syncdl / 100 + 5;
+	else
+		return dtdl_or_syncdl / 100;
+}
+
+static void rcar_drif_validate_dtdl_syncdl(struct rcar_drif_chan *ch, u32 dtdl,
+					   u32 syncdl)
+{
+	/* Sanity checks */
+	if (dtdl > 200 || syncdl > 300) {
+		dev_warn(ch->dev, "invalid dtdl %u or syncdl %u\n",
+			 dtdl, syncdl);
+		return;
+	}
+	if ((dtdl + syncdl) % 100) {
+		dev_warn(ch->dev, "sum of dtdl %u or syncdl %u not OK\n",
+			 dtdl, syncdl);
+		return;
+	}
+	ch->mdr1 &= (~(7 << 20) & ~(7 << 16));	/* Clear current settings */
+	ch->mdr1 |= (rcar_drif_get_dtdl_or_syncdl_bits(dtdl) << 20);
+	ch->mdr1 |= (rcar_drif_get_dtdl_or_syncdl_bits(syncdl) << 16);
+}
+
+static void rcar_drif_parse_properties(struct rcar_drif_chan *ch)
+{
+	u32 val, dtdl = 100, syncdl = 0;
+	struct device_node *np = ch->dev->of_node;
+
+	/* Set the defaults and check for overrides */
+	ch->mdr1 = RCAR_DRIF_SIRMDR1_SYNCMD_LR;	/* Default */
+	if (!of_property_read_u32(np, "renesas,syncmd", &val))
+		rcar_drif_validate_syncmd(ch, val);
+
+	if (of_find_property(np, "renesas,lsb-first", NULL))
+		ch->mdr1 |= RCAR_DRIF_SIRMDR1_LSB_FIRST;
+	else
+		ch->mdr1 |= RCAR_DRIF_SIRMDR1_MSB_FIRST;
+
+	if (of_find_property(np, "renesas,syncac-pol-high", NULL))
+		ch->mdr1 |= RCAR_DRIF_SIRMDR1_SYNCAC_POL_HIGH;
+	else
+		ch->mdr1 |= RCAR_DRIF_SIRMDR1_SYNCAC_POL_LOW;
+
+	ch->mdr1 |= RCAR_DRIF_SIRMDR1_DTDL_1 | RCAR_DRIF_SIRMDR1_SYNCDL_0;
+	of_property_read_u32(np, "renesas,dtdl", &dtdl);
+	of_property_read_u32(np, "renesas,syncdl", &syncdl);
+	rcar_drif_validate_dtdl_syncdl(ch, dtdl, syncdl);
+
+	dev_info(ch->dev, "Parsed SIRMDR1 0x%08x\n", ch->mdr1);
+}
+
+static int rcar_drif_probe(struct platform_device *pdev)
+{
+	struct rcar_drif_chan *ch;
+	struct device_node *of_child;
+	unsigned long hw_schans_mask = 0;
+	int ret;
+	u32 i;
+
+	of_child = of_get_child_by_name(pdev->dev.of_node, "sub-channel0");
+	if (of_child && of_device_is_available(of_child))
+		hw_schans_mask |= BIT(0);	/* Sub-channel 0 */
+
+	of_child = of_get_child_by_name(pdev->dev.of_node, "sub-channel1");
+	if (of_child && of_device_is_available(of_child))
+		hw_schans_mask |= BIT(1);	/* Sub-channel 1 */
+
+	/* Reserve memory for driver structure */
+	ch = kzalloc(sizeof(*ch), GFP_KERNEL);
+	if (!ch) {
+		ret = PTR_ERR(ch);
+		dev_err(&pdev->dev, "failed alloc drif context\n");
+		return ret;
+	}
+	ch->dev = &pdev->dev;
+
+	/* Parse device tree optional properties */
+	rcar_drif_parse_properties(ch);
+
+	/* Setup enabled sub-channels */
+	for_each_set_bit(i, &hw_schans_mask, RCAR_DRIF_MAX_SUBCHANS) {
+		struct clk *clkp;
+		struct resource	*res;
+		void __iomem *base;
+
+		/* Peripheral clock */
+		clkp = devm_clk_get(&pdev->dev, (i == 0 ? "fck0" : "fck1"));
+		if (IS_ERR(clkp)) {
+			ret = PTR_ERR(clkp);
+			dev_err(&pdev->dev, "schan%u: clk get failed\n", i);
+			goto err_free_mem;
+		}
+
+		/* Register map */
+		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
+		base = devm_ioremap_resource(&pdev->dev, res);
+		if (IS_ERR(base)) {
+			ret = PTR_ERR(base);
+			dev_err(&pdev->dev, "schan%u: io res get failed\n", i);
+			break;
+		}
+
+		/* Reserve memory for enabled sub-channels */
+		ch->schan[i] = kzalloc(sizeof(*ch->schan[i]), GFP_KERNEL);
+		if (!ch->schan[i]) {
+			ret = PTR_ERR(ch);
+			dev_err(&pdev->dev, "failed alloc sub-channel\n");
+			goto err_free_mem;
+		}
+		ch->schan[i]->clkp = clkp;
+		ch->schan[i]->base = base;
+		ch->schan[i]->num = i;
+		ch->schan[i]->start = res->start;
+		ch->schan[i]->parent = ch;
+		ch->num_hw_schans++;
+	}
+	ch->hw_schans_mask = hw_schans_mask;
+
+	/* Validate any supported format for enabled sub-channels */
+	ret = rcar_drif_set_default_format(ch);
+	if (ret)
+		goto err_free_mem;
+
+	/* Set defaults */
+	ch->num_hwbufs = RCAR_DRIF_DEFAULT_NUM_HWBUFS;
+	ch->hwbuf_size = RCAR_DRIF_DEFAULT_HWBUF_SIZE;
+
+	mutex_init(&ch->v4l2_mutex);
+	mutex_init(&ch->vb_queue_mutex);
+	spin_lock_init(&ch->queued_bufs_lock);
+	INIT_LIST_HEAD(&ch->queued_bufs);
+
+	/* Init videobuf2 queue structure */
+	ch->vb_queue.type = V4L2_BUF_TYPE_SDR_CAPTURE;
+	ch->vb_queue.io_modes = VB2_READ | VB2_MMAP | VB2_DMABUF;
+	ch->vb_queue.drv_priv = ch;
+	ch->vb_queue.buf_struct_size = sizeof(struct rcar_drif_frame_buf);
+	ch->vb_queue.ops = &rcar_drif_vb2_ops;
+	ch->vb_queue.mem_ops = &vb2_vmalloc_memops;
+	ch->vb_queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
+
+	/* Init videobuf2 queue */
+	ret = vb2_queue_init(&ch->vb_queue);
+	if (ret) {
+		dev_err(ch->dev, "Could not initialize vb2 queue\n");
+		goto err_free_mem;
+	}
+
+	/* Init video_device structure */
+	ch->vdev = rcar_drif_template;
+	ch->vdev.lock = &ch->v4l2_mutex;
+	ch->vdev.queue = &ch->vb_queue;
+	ch->vdev.queue->lock = &ch->vb_queue_mutex;
+	ch->vdev.ctrl_handler = &ch->ctrl_hdl;
+	video_set_drvdata(&ch->vdev, ch);
+
+	/* Register the v4l2_device structure */
+	ch->v4l2_dev.release = rcar_drif_video_release;
+	ret = v4l2_device_register(&pdev->dev, &ch->v4l2_dev);
+	if (ret) {
+		dev_err(ch->dev, "Failed to register v4l2-device (%d)\n", ret);
+		goto err_free_mem;
+	}
+
+	ch->vdev.v4l2_dev = &ch->v4l2_dev;
+
+	/* Parse subdevs after v4l2_device_register because if the subdev
+	 * is already probed, bound and complete will get called immediately
+	 */
+	ret = rcar_drif_parse_subdevs(&pdev->dev, &ch->notifier);
+	if (ret)
+		goto err_free_mem;
+
+	dev_info(ch->dev, "Num of subdevs %d\n", ch->notifier.num_subdevs);
+	ch->notifier.bound = rcar_drif_notify_bound;
+	ch->notifier.complete = rcar_drif_notify_complete;
+
+	ret = v4l2_async_notifier_register(&ch->v4l2_dev, &ch->notifier);
+	if (ret < 0) {
+		dev_err(ch->dev, "notifier registration failed\n");
+		goto err_unregister_v4l2_dev;
+	}
+
+	/* Register SDR device */
+	ret = video_register_device(&ch->vdev, VFL_TYPE_SDR, -1);
+	if (ret) {
+		dev_err(ch->dev, "Failed to register as video device (%d)\n",
+				ret);
+		goto err_unregister;
+	}
+
+	platform_set_drvdata(pdev, ch);
+	dev_notice(ch->dev, "probed\n");
+	return 0;
+
+err_unregister:
+	v4l2_async_notifier_unregister(&ch->notifier);
+err_unregister_v4l2_dev:
+	v4l2_device_unregister(&ch->v4l2_dev);
+err_free_mem:
+	for_each_set_bit(i, &hw_schans_mask, RCAR_DRIF_MAX_SUBCHANS)
+		kfree(ch->schan[i]);
+	kfree(ch);
+	return ret;
+}
+
+static int rcar_drif_remove(struct platform_device *pdev)
+{
+	struct rcar_drif_chan *ch = platform_get_drvdata(pdev);
+
+	v4l2_ctrl_handler_free(ch->v4l2_dev.ctrl_handler);
+	v4l2_async_notifier_unregister(&ch->notifier);
+	video_unregister_device(&ch->vdev);
+	dev_notice(ch->dev, "removed\n");
+	v4l2_device_put(&ch->v4l2_dev);
+	return 0;
+}
+
+static int __maybe_unused rcar_drif_suspend(struct device *dev)
+{
+	return 0;
+}
+
+static int __maybe_unused rcar_drif_resume(struct device *dev)
+{
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(rcar_drif_pm_ops, rcar_drif_suspend,
+			 rcar_drif_resume);
+
+static const struct of_device_id rcar_drif_of_table[] = {
+	{ .compatible = "renesas,rcar-gen3-drif" },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(of, rcar_drif_of_table);
+
+#define RCAR_DRIF_DRV_NAME "rcar_drif"
+static struct platform_driver rcar_drif_driver = {
+	.driver = {
+		.name = RCAR_DRIF_DRV_NAME,
+		.of_match_table = of_match_ptr(rcar_drif_of_table),
+		.pm = &rcar_drif_pm_ops,
+		},
+	.probe = rcar_drif_probe,
+	.remove = rcar_drif_remove,
+};
+
+module_platform_driver(rcar_drif_driver);
+
+MODULE_DESCRIPTION("Renesas R-Car Gen3 DRIF driver");
+MODULE_ALIAS("platform:" RCAR_DRIF_DRV_NAME);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Ramesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com>");
-- 
1.9.1