// SPDX-License-Identifier: GPL-2.0+
/*
 * R-Car Gen3 Digital Radio Interface (DRIF) driver
 *
 * Copyright (C) 2017 Renesas Electronics Corporation
 *
 * 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 DRIFx (as per datasheet) contains two internal
 * channels DRIFx0 & DRIFx1 within itself with each having its own resources
 * like module clk, register set, irq and dma. These internal channels share
 * common CLK & SYNC from master. The two data pins D0 & D1 shall be
 * considered to represent the two internal channels. This internal split
 * is not visible to the master device.
 *
 * Depending on the master device, a DRIF channel can use
 *  (1) both internal channels (D0 & D1) to receive data in parallel (or)
 *  (2) one internal channel (D0 or D1) to receive data
 *
 * The primary design goal of this controller is to act as a Digital 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 a 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.
 *
 * The DRIF h/w can support I2S mode and Frame start synchronization pulse mode.
 * This driver is tested for I2S mode only because of the availability of
 * suitable master devices. Hence, not all configurable options of DRIF h/w
 * like lsb/msb first, syncdl, dtdl etc. are exposed via DT and I2S defaults
 * are used. These can be exposed later if needed after testing.
 */
#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_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>

/* 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 */

/* SIRMDR1 */
#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_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_CHANNEL                   2
#define RCAR_SDR_BUFFER_SIZE                    SZ_64K

/* Internal buffer status flags */
#define RCAR_DRIF_BUF_DONE                      BIT(0)  /* DMA completed */
#define RCAR_DRIF_BUF_OVERFLOW                  BIT(1)  /* Overflow detected */

#define to_rcar_drif_buf_pair(sdr, ch_num, idx)                 \
        (&((sdr)->ch[!(ch_num)]->buf[(idx)]))

#define for_each_rcar_drif_channel(ch, ch_mask)                 \
        for_each_set_bit(ch, ch_mask, RCAR_DRIF_MAX_CHANNEL)

/* Debug */
#define rdrif_dbg(sdr, fmt, arg...)                             \
        dev_dbg(sdr->v4l2_dev.dev, fmt, ## arg)

#define rdrif_err(sdr, fmt, arg...)                             \
        dev_err(sdr->v4l2_dev.dev, fmt, ## arg)

/* Stream formats */
struct rcar_drif_format {
        u32     pixelformat;
        u32     buffersize;
        u32     bitlen;
        u32     wdcnt;
        u32     num_ch;
};

/* Format descriptions for capture */
static const struct rcar_drif_format formats[] = {
        {
                .pixelformat    = V4L2_SDR_FMT_PCU16BE,
                .buffersize     = RCAR_SDR_BUFFER_SIZE,
                .bitlen         = 16,
                .wdcnt          = 1,
                .num_ch         = 2,
        },
        {
                .pixelformat    = V4L2_SDR_FMT_PCU18BE,
                .buffersize     = RCAR_SDR_BUFFER_SIZE,
                .bitlen         = 18,
                .wdcnt          = 1,
                .num_ch         = 2,
        },
        {
                .pixelformat    = V4L2_SDR_FMT_PCU20BE,
                .buffersize     = RCAR_SDR_BUFFER_SIZE,
                .bitlen         = 20,
                .wdcnt          = 1,
                .num_ch         = 2,
        },
};

/* Buffer for a received frame from one or both internal channels */
struct rcar_drif_frame_buf {
        /* Common v4l buffer stuff -- must be first */
        struct vb2_v4l2_buffer vb;
        struct list_head list;
};

/* OF graph endpoint's V4L2 async data */
struct rcar_drif_graph_ep {
        struct v4l2_subdev *subdev;     /* Async matched subdev */
        struct v4l2_async_subdev asd;   /* Async sub-device descriptor */
};

/* DMA buffer */
struct rcar_drif_hwbuf {
        void *addr;                     /* CPU-side address */
        unsigned int status;            /* Buffer status flags */
};

/* Internal channel */
struct rcar_drif {
        struct rcar_drif_sdr *sdr;      /* Group device */
        struct platform_device *pdev;   /* Channel's pdev */
        void __iomem *base;             /* Base register address */
        resource_size_t start;          /* I/O resource offset */
        struct dma_chan *dmach;         /* Reserved DMA channel */
        struct clk *clk;                /* Module clock */
        struct rcar_drif_hwbuf buf[RCAR_DRIF_NUM_HWBUFS]; /* H/W bufs */
        dma_addr_t dma_handle;          /* Handle for all bufs */
        unsigned int num;               /* Channel number */
        bool acting_sdr;                /* Channel acting as SDR device */
};

/* DRIF V4L2 SDR */
struct rcar_drif_sdr {
        struct device *dev;             /* Platform device */
        struct video_device *vdev;      /* V4L2 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 */
        spinlock_t dma_lock;            /* To serialize DMA cb of channels */

        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) */
        struct rcar_drif_graph_ep ep;   /* Endpoint V4L2 async data */

        /* Current V4L2 SDR format ptr */
        const struct rcar_drif_format *fmt;

        /* Device tree SYNC properties */
        u32 mdr1;

        /* Internals */
        struct rcar_drif *ch[RCAR_DRIF_MAX_CHANNEL]; /* DRIFx0,1 */
        unsigned long hw_ch_mask;       /* Enabled channels per DT */
        unsigned long cur_ch_mask;      /* Used channels for an SDR FMT */
        u32 num_hw_ch;                  /* Num of DT enabled channels */
        u32 num_cur_ch;                 /* Num of used channels */
        u32 hwbuf_size;                 /* Each DMA buffer size */
        u32 produced;                   /* Buffers produced by sdr dev */
};

/* Register access functions */
static void rcar_drif_write(struct rcar_drif *ch, u32 offset, u32 data)
{
        writel(data, ch->base + offset);
}

static u32 rcar_drif_read(struct rcar_drif *ch, u32 offset)
{
        return readl(ch->base + offset);
}

/* Release DMA channels */
static void rcar_drif_release_dmachannels(struct rcar_drif_sdr *sdr)
{
        unsigned int i;

        for_each_rcar_drif_channel(i, &sdr->cur_ch_mask)
                if (sdr->ch[i]->dmach) {
                        dma_release_channel(sdr->ch[i]->dmach);
                        sdr->ch[i]->dmach = NULL;
                }
}

/* Allocate DMA channels */
static int rcar_drif_alloc_dmachannels(struct rcar_drif_sdr *sdr)
{
        struct dma_slave_config dma_cfg;
        unsigned int i;
        int ret;

        for_each_rcar_drif_channel(i, &sdr->cur_ch_mask) {
                struct rcar_drif *ch = sdr->ch[i];

                ch->dmach = dma_request_chan(&ch->pdev->dev, "rx");
                if (IS_ERR(ch->dmach)) {
                        ret = PTR_ERR(ch->dmach);
                        if (ret != -EPROBE_DEFER)
                                rdrif_err(sdr,
                                          "ch%u: dma channel req failed: %pe\n",
                                          i, ch->dmach);
                        ch->dmach = NULL;
                        goto dmach_error;
                }

                /* Configure slave */
                memset(&dma_cfg, 0, sizeof(dma_cfg));
                dma_cfg.src_addr = (phys_addr_t)(ch->start + RCAR_DRIF_SIRFDR);
                dma_cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
                ret = dmaengine_slave_config(ch->dmach, &dma_cfg);
                if (ret) {
                        rdrif_err(sdr, "ch%u: dma slave config failed\n", i);
                        goto dmach_error;
                }
        }
        return 0;

dmach_error:
        rcar_drif_release_dmachannels(sdr);
        return ret;
}

/* Release queued vb2 buffers */
static void rcar_drif_release_queued_bufs(struct rcar_drif_sdr *sdr,
                                          enum vb2_buffer_state state)
{
        struct rcar_drif_frame_buf *fbuf, *tmp;
        unsigned long flags;

        spin_lock_irqsave(&sdr->queued_bufs_lock, flags);
        list_for_each_entry_safe(fbuf, tmp, &sdr->queued_bufs, list) {
                list_del(&fbuf->list);
                vb2_buffer_done(&fbuf->vb.vb2_buf, state);
        }
        spin_unlock_irqrestore(&sdr->queued_bufs_lock, flags);
}

/* Set MDR defaults */
static inline void rcar_drif_set_mdr1(struct rcar_drif_sdr *sdr)
{
        unsigned int i;

        /* Set defaults for enabled internal channels */
        for_each_rcar_drif_channel(i, &sdr->cur_ch_mask) {
                /* Refer MSIOF section in manual for this register setting */
                rcar_drif_write(sdr->ch[i], RCAR_DRIF_SITMDR1,
                                RCAR_DRIF_SITMDR1_PCON);

                /* Setup MDR1 value */
                rcar_drif_write(sdr->ch[i], RCAR_DRIF_SIRMDR1, sdr->mdr1);

                rdrif_dbg(sdr, "ch%u: mdr1 = 0x%08x",
                          i, rcar_drif_read(sdr->ch[i], RCAR_DRIF_SIRMDR1));
        }
}

/* Set DRIF receive format */
static int rcar_drif_set_format(struct rcar_drif_sdr *sdr)
{
        unsigned int i;

        rdrif_dbg(sdr, "setfmt: bitlen %u wdcnt %u num_ch %u\n",
                  sdr->fmt->bitlen, sdr->fmt->wdcnt, sdr->fmt->num_ch);

        /* Sanity check */
        if (sdr->fmt->num_ch > sdr->num_cur_ch) {
                rdrif_err(sdr, "fmt num_ch %u cur_ch %u mismatch\n",
                          sdr->fmt->num_ch, sdr->num_cur_ch);
                return -EINVAL;
        }

        /* Setup group, bitlen & wdcnt */
        for_each_rcar_drif_channel(i, &sdr->cur_ch_mask) {
                u32 mdr;

                /* Two groups */
                mdr = RCAR_DRIF_MDR_GRPCNT(2) |
                        RCAR_DRIF_MDR_BITLEN(sdr->fmt->bitlen) |
                        RCAR_DRIF_MDR_WDCNT(sdr->fmt->wdcnt);
                rcar_drif_write(sdr->ch[i], RCAR_DRIF_SIRMDR2, mdr);

                mdr = RCAR_DRIF_MDR_BITLEN(sdr->fmt->bitlen) |
                        RCAR_DRIF_MDR_WDCNT(sdr->fmt->wdcnt);
                rcar_drif_write(sdr->ch[i], RCAR_DRIF_SIRMDR3, mdr);

                rdrif_dbg(sdr, "ch%u: new mdr[2,3] = 0x%08x, 0x%08x\n",
                          i, rcar_drif_read(sdr->ch[i], RCAR_DRIF_SIRMDR2),
                          rcar_drif_read(sdr->ch[i], RCAR_DRIF_SIRMDR3));
        }
        return 0;
}

/* Release DMA buffers */
static void rcar_drif_release_buf(struct rcar_drif_sdr *sdr)
{
        unsigned int i;

        for_each_rcar_drif_channel(i, &sdr->cur_ch_mask) {
                struct rcar_drif *ch = sdr->ch[i];

                /* First entry contains the dma buf ptr */
                if (ch->buf[0].addr) {
                        dma_free_coherent(&ch->pdev->dev,
                                sdr->hwbuf_size * RCAR_DRIF_NUM_HWBUFS,
                                ch->buf[0].addr, ch->dma_handle);
                        ch->buf[0].addr = NULL;
                }
        }
}

/* Request DMA buffers */
static int rcar_drif_request_buf(struct rcar_drif_sdr *sdr)
{
        int ret = -ENOMEM;
        unsigned int i, j;
        void *addr;

        for_each_rcar_drif_channel(i, &sdr->cur_ch_mask) {
                struct rcar_drif *ch = sdr->ch[i];

                /* Allocate DMA buffers */
                addr = dma_alloc_coherent(&ch->pdev->dev,
                                sdr->hwbuf_size * RCAR_DRIF_NUM_HWBUFS,
                                &ch->dma_handle, GFP_KERNEL);
                if (!addr) {
                        rdrif_err(sdr,
                        "ch%u: dma alloc failed. num hwbufs %u size %u\n",
                        i, RCAR_DRIF_NUM_HWBUFS, sdr->hwbuf_size);
                        goto error;
                }

                /* Split the chunk and populate bufctxt */
                for (j = 0; j < RCAR_DRIF_NUM_HWBUFS; j++) {
                        ch->buf[j].addr = addr + (j * sdr->hwbuf_size);
                        ch->buf[j].status = 0;
                }
        }
        return 0;
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_sdr *sdr = vb2_get_drv_priv(vq);

        /* 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(sdr->fmt->buffersize);
        rdrif_dbg(sdr, "num_bufs %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_sdr *sdr = 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;

        rdrif_dbg(sdr, "buf_queue idx %u\n", vb->index);
        spin_lock_irqsave(&sdr->queued_bufs_lock, flags);
        list_add_tail(&fbuf->list, &sdr->queued_bufs);
        spin_unlock_irqrestore(&sdr->queued_bufs_lock, flags);
}

/* Get a frame buf from list */
static struct rcar_drif_frame_buf *
rcar_drif_get_fbuf(struct rcar_drif_sdr *sdr)
{
        struct rcar_drif_frame_buf *fbuf;
        unsigned long flags;

        spin_lock_irqsave(&sdr->queued_bufs_lock, flags);
        fbuf = list_first_entry_or_null(&sdr->queued_bufs, struct
                                        rcar_drif_frame_buf, list);
        if (!fbuf) {
                /*
                 * App is late in enqueing buffers. Samples lost & there will
                 * be a gap in sequence number when app recovers
                 */
                rdrif_dbg(sdr, "\napp late: prod %u\n", sdr->produced);
                spin_unlock_irqrestore(&sdr->queued_bufs_lock, flags);
                return NULL;
        }
        list_del(&fbuf->list);
        spin_unlock_irqrestore(&sdr->queued_bufs_lock, flags);

        return fbuf;
}

/* Helpers to set/clear buf pair status */
static inline bool rcar_drif_bufs_done(struct rcar_drif_hwbuf **buf)
{
        return (buf[0]->status & buf[1]->status & RCAR_DRIF_BUF_DONE);
}

static inline bool rcar_drif_bufs_overflow(struct rcar_drif_hwbuf **buf)
{
        return ((buf[0]->status | buf[1]->status) & RCAR_DRIF_BUF_OVERFLOW);
}

static inline void rcar_drif_bufs_clear(struct rcar_drif_hwbuf **buf,
                                        unsigned int bit)
{
        unsigned int i;

        for (i = 0; i < RCAR_DRIF_MAX_CHANNEL; i++)
                buf[i]->status &= ~bit;
}

/* Channel DMA complete */
static void rcar_drif_channel_complete(struct rcar_drif *ch, u32 idx)
{
        u32 str;

        ch->buf[idx].status |= RCAR_DRIF_BUF_DONE;

        /* Check for DRIF errors */
        str = rcar_drif_read(ch, RCAR_DRIF_SISTR);
        if (unlikely(str & RCAR_DRIF_RFOVF)) {
                /* Writing the same clears it */
                rcar_drif_write(ch, RCAR_DRIF_SISTR, str);

                /* Overflow: some samples are lost */
                ch->buf[idx].status |= RCAR_DRIF_BUF_OVERFLOW;
        }
}

/* DMA callback for each stage */
static void rcar_drif_dma_complete(void *dma_async_param)
{
        struct rcar_drif *ch = dma_async_param;
        struct rcar_drif_sdr *sdr = ch->sdr;
        struct rcar_drif_hwbuf *buf[RCAR_DRIF_MAX_CHANNEL];
        struct rcar_drif_frame_buf *fbuf;
        bool overflow = false;
        u32 idx, produced;
        unsigned int i;

        spin_lock(&sdr->dma_lock);

        /* DMA can be terminated while the callback was waiting on lock */
        if (!vb2_is_streaming(&sdr->vb_queue)) {
                spin_unlock(&sdr->dma_lock);
                return;
        }

        idx = sdr->produced % RCAR_DRIF_NUM_HWBUFS;
        rcar_drif_channel_complete(ch, idx);

        if (sdr->num_cur_ch == RCAR_DRIF_MAX_CHANNEL) {
                buf[0] = ch->num ? to_rcar_drif_buf_pair(sdr, ch->num, idx) :
                                &ch->buf[idx];
                buf[1] = ch->num ? &ch->buf[idx] :
                                to_rcar_drif_buf_pair(sdr, ch->num, idx);

                /* Check if both DMA buffers are done */
                if (!rcar_drif_bufs_done(buf)) {
                        spin_unlock(&sdr->dma_lock);
                        return;
                }

                /* Clear buf done status */
                rcar_drif_bufs_clear(buf, RCAR_DRIF_BUF_DONE);

                if (rcar_drif_bufs_overflow(buf)) {
                        overflow = true;
                        /* Clear the flag in status */
                        rcar_drif_bufs_clear(buf, RCAR_DRIF_BUF_OVERFLOW);
                }
        } else {
                buf[0] = &ch->buf[idx];
                if (buf[0]->status & RCAR_DRIF_BUF_OVERFLOW) {
                        overflow = true;
                        /* Clear the flag in status */
                        buf[0]->status &= ~RCAR_DRIF_BUF_OVERFLOW;
                }
        }

        /* Buffer produced for consumption */
        produced = sdr->produced++;
        spin_unlock(&sdr->dma_lock);

        rdrif_dbg(sdr, "ch%u: prod %u\n", ch->num, produced);

        /* Get fbuf */
        fbuf = rcar_drif_get_fbuf(sdr);
        if (!fbuf)
                return;

        for (i = 0; i < RCAR_DRIF_MAX_CHANNEL; i++)
                memcpy(vb2_plane_vaddr(&fbuf->vb.vb2_buf, 0) +
                       i * sdr->hwbuf_size, buf[i]->addr, sdr->hwbuf_size);

        fbuf->vb.field = V4L2_FIELD_NONE;
        fbuf->vb.sequence = produced;
        fbuf->vb.vb2_buf.timestamp = ktime_get_ns();
        vb2_set_plane_payload(&fbuf->vb.vb2_buf, 0, sdr->fmt->buffersize);

        /* Set error state on overflow */
        vb2_buffer_done(&fbuf->vb.vb2_buf,
                        overflow ? VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);
}

static int rcar_drif_qbuf(struct rcar_drif *ch)
{
        struct rcar_drif_sdr *sdr = ch->sdr;
        dma_addr_t addr = ch->dma_handle;
        struct dma_async_tx_descriptor *rxd;
        dma_cookie_t cookie;
        int ret = -EIO;

        /* Setup cyclic DMA with given buffers */
        rxd = dmaengine_prep_dma_cyclic(ch->dmach, addr,
                                        sdr->hwbuf_size * RCAR_DRIF_NUM_HWBUFS,
                                        sdr->hwbuf_size, DMA_DEV_TO_MEM,
                                        DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
        if (!rxd) {
                rdrif_err(sdr, "ch%u: prep dma cyclic failed\n", ch->num);
                return ret;
        }

        /* Submit descriptor */
        rxd->callback = rcar_drif_dma_complete;
        rxd->callback_param = ch;
        cookie = dmaengine_submit(rxd);
        if (dma_submit_error(cookie)) {
                rdrif_err(sdr, "ch%u: dma submit failed\n", ch->num);
                return ret;
        }

        dma_async_issue_pending(ch->dmach);
        return 0;
}

/* Enable reception */
static int rcar_drif_enable_rx(struct rcar_drif_sdr *sdr)
{
        unsigned int i;
        u32 ctr;
        int ret = -EINVAL;

        /*
         * When both internal channels are enabled, they can be synchronized
         * only by the master
         */

        /* Enable receive */
        for_each_rcar_drif_channel(i, &sdr->cur_ch_mask) {
                ctr = rcar_drif_read(sdr->ch[i], RCAR_DRIF_SICTR);
                ctr |= (RCAR_DRIF_SICTR_RX_RISING_EDGE |
                         RCAR_DRIF_SICTR_RX_EN);
                rcar_drif_write(sdr->ch[i], RCAR_DRIF_SICTR, ctr);
        }

        /* Check receive enabled */
        for_each_rcar_drif_channel(i, &sdr->cur_ch_mask) {
                ret = readl_poll_timeout(sdr->ch[i]->base + RCAR_DRIF_SICTR,
                                ctr, ctr & RCAR_DRIF_SICTR_RX_EN, 7, 100000);
                if (ret) {
                        rdrif_err(sdr, "ch%u: rx en failed. ctr 0x%08x\n", i,
                                  rcar_drif_read(sdr->ch[i], RCAR_DRIF_SICTR));
                        break;
                }
        }
        return ret;
}

/* Disable reception */
static void rcar_drif_disable_rx(struct rcar_drif_sdr *sdr)
{
        unsigned int i;
        u32 ctr;
        int ret;

        /* Disable receive */
        for_each_rcar_drif_channel(i, &sdr->cur_ch_mask) {
                ctr = rcar_drif_read(sdr->ch[i], RCAR_DRIF_SICTR);
                ctr &= ~RCAR_DRIF_SICTR_RX_EN;
                rcar_drif_write(sdr->ch[i], RCAR_DRIF_SICTR, ctr);
        }

        /* Check receive disabled */
        for_each_rcar_drif_channel(i, &sdr->cur_ch_mask) {
                ret = readl_poll_timeout(sdr->ch[i]->base + RCAR_DRIF_SICTR,
                                ctr, !(ctr & RCAR_DRIF_SICTR_RX_EN), 7, 100000);
                if (ret)
                        dev_warn(&sdr->vdev->dev,
                        "ch%u: failed to disable rx. ctr 0x%08x\n",
                        i, rcar_drif_read(sdr->ch[i], RCAR_DRIF_SICTR));
        }
}

/* Stop channel */
static void rcar_drif_stop_channel(struct rcar_drif *ch)
{
        /* Disable DMA receive interrupt */
        rcar_drif_write(ch, RCAR_DRIF_SIIER, 0x00000000);

        /* Terminate all DMA transfers */
        dmaengine_terminate_sync(ch->dmach);
}

/* Stop receive operation */
static void rcar_drif_stop(struct rcar_drif_sdr *sdr)
{
        unsigned int i;

        /* Disable Rx */
        rcar_drif_disable_rx(sdr);

        for_each_rcar_drif_channel(i, &sdr->cur_ch_mask)
                rcar_drif_stop_channel(sdr->ch[i]);
}

/* Start channel */
static int rcar_drif_start_channel(struct rcar_drif *ch)
{
        struct rcar_drif_sdr *sdr = ch->sdr;
        u32 ctr, str;
        int ret;

        /* Reset receive */
        rcar_drif_write(ch, RCAR_DRIF_SICTR, RCAR_DRIF_SICTR_RESET);
        ret = readl_poll_timeout(ch->base + RCAR_DRIF_SICTR, ctr,
                                 !(ctr & RCAR_DRIF_SICTR_RESET), 7, 100000);
        if (ret) {
                rdrif_err(sdr, "ch%u: failed to reset rx. ctr 0x%08x\n",
                          ch->num, rcar_drif_read(ch, RCAR_DRIF_SICTR));
                return ret;
        }

        /* Queue buffers for DMA */
        ret = rcar_drif_qbuf(ch);
        if (ret)
                return ret;

        /* Clear status register flags */
        str = RCAR_DRIF_RFFUL | RCAR_DRIF_REOF | RCAR_DRIF_RFSERR |
                RCAR_DRIF_RFUDF | RCAR_DRIF_RFOVF;
        rcar_drif_write(ch, RCAR_DRIF_SISTR, str);

        /* Enable DMA receive interrupt */
        rcar_drif_write(ch, RCAR_DRIF_SIIER, 0x00009000);

        return ret;
}

/* Start receive operation */
static int rcar_drif_start(struct rcar_drif_sdr *sdr)
{
        unsigned long enabled = 0;
        unsigned int i;
        int ret;

        for_each_rcar_drif_channel(i, &sdr->cur_ch_mask) {
                ret = rcar_drif_start_channel(sdr->ch[i]);
                if (ret)
                        goto start_error;
                enabled |= BIT(i);
        }

        ret = rcar_drif_enable_rx(sdr);
        if (ret)
                goto enable_error;

        sdr->produced = 0;
        return ret;

enable_error:
        rcar_drif_disable_rx(sdr);
start_error:
        for_each_rcar_drif_channel(i, &enabled)
                rcar_drif_stop_channel(sdr->ch[i]);

        return ret;
}

/* Start streaming */
static int rcar_drif_start_streaming(struct vb2_queue *vq, unsigned int count)
{
        struct rcar_drif_sdr *sdr = vb2_get_drv_priv(vq);
        unsigned long enabled = 0;
        unsigned int i;
        int ret;

        mutex_lock(&sdr->v4l2_mutex);

        for_each_rcar_drif_channel(i, &sdr->cur_ch_mask) {
                ret = clk_prepare_enable(sdr->ch[i]->clk);
                if (ret)
                        goto error;
                enabled |= BIT(i);
        }

        /* Set default MDRx settings */
        rcar_drif_set_mdr1(sdr);

        /* Set new format */
        ret = rcar_drif_set_format(sdr);
        if (ret)
                goto error;

        if (sdr->num_cur_ch == RCAR_DRIF_MAX_CHANNEL)
                sdr->hwbuf_size = sdr->fmt->buffersize / RCAR_DRIF_MAX_CHANNEL;
        else
                sdr->hwbuf_size = sdr->fmt->buffersize;

        rdrif_dbg(sdr, "num hwbufs %u, hwbuf_size %u\n",
                RCAR_DRIF_NUM_HWBUFS, sdr->hwbuf_size);

        /* Alloc DMA channel */
        ret = rcar_drif_alloc_dmachannels(sdr);
        if (ret)
                goto error;

        /* Request buffers */
        ret = rcar_drif_request_buf(sdr);
        if (ret)
                goto error;

        /* Start Rx */
        ret = rcar_drif_start(sdr);
        if (ret)
                goto error;

        mutex_unlock(&sdr->v4l2_mutex);

        return ret;

error:
        rcar_drif_release_queued_bufs(sdr, VB2_BUF_STATE_QUEUED);
        rcar_drif_release_buf(sdr);
        rcar_drif_release_dmachannels(sdr);
        for_each_rcar_drif_channel(i, &enabled)
                clk_disable_unprepare(sdr->ch[i]->clk);

        mutex_unlock(&sdr->v4l2_mutex);

        return ret;
}

/* Stop streaming */
static void rcar_drif_stop_streaming(struct vb2_queue *vq)
{
        struct rcar_drif_sdr *sdr = vb2_get_drv_priv(vq);
        unsigned int i;

        mutex_lock(&sdr->v4l2_mutex);

        /* Stop hardware streaming */
        rcar_drif_stop(sdr);

        /* Return all queued buffers to vb2 */
        rcar_drif_release_queued_bufs(sdr, VB2_BUF_STATE_ERROR);

        /* Release buf */
        rcar_drif_release_buf(sdr);

        /* Release DMA channel resources */
        rcar_drif_release_dmachannels(sdr);

        for_each_rcar_drif_channel(i, &sdr->cur_ch_mask)
                clk_disable_unprepare(sdr->ch[i]->clk);

        mutex_unlock(&sdr->v4l2_mutex);
}

/* Vb2 ops */
static const 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_sdr *sdr = video_drvdata(file);

        strscpy(cap->driver, KBUILD_MODNAME, sizeof(cap->driver));
        strscpy(cap->card, sdr->vdev->name, sizeof(cap->card));
        snprintf(cap->bus_info, sizeof(cap->bus_info), "platform:%s",
                 sdr->vdev->name);

        return 0;
}

static int rcar_drif_set_default_format(struct rcar_drif_sdr *sdr)
{
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(formats); i++) {
                /* Matching fmt based on required channels is set as default */
                if (sdr->num_hw_ch == formats[i].num_ch) {
                        sdr->fmt = &formats[i];
                        sdr->cur_ch_mask = sdr->hw_ch_mask;
                        sdr->num_cur_ch = sdr->num_hw_ch;
                        dev_dbg(sdr->dev, "default fmt[%u]: mask %lu num %u\n",
                                i, sdr->cur_ch_mask, sdr->num_cur_ch);
                        return 0;
                }
        }
        return -EINVAL;
}

static int rcar_drif_enum_fmt_sdr_cap(struct file *file, void *priv,
                                      struct v4l2_fmtdesc *f)
{
        if (f->index >= ARRAY_SIZE(formats))
                return -EINVAL;

        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_sdr *sdr = video_drvdata(file);

        memset(f->fmt.sdr.reserved, 0, sizeof(f->fmt.sdr.reserved));
        f->fmt.sdr.pixelformat = sdr->fmt->pixelformat;
        f->fmt.sdr.buffersize = sdr->fmt->buffersize;

        return 0;
}

static int rcar_drif_s_fmt_sdr_cap(struct file *file, void *priv,
                                   struct v4l2_format *f)
{
        struct rcar_drif_sdr *sdr = video_drvdata(file);
        struct vb2_queue *q = &sdr->vb_queue;
        unsigned int i;

        if (vb2_is_busy(q))
                return -EBUSY;

        for (i = 0; i < ARRAY_SIZE(formats); i++) {
                if (formats[i].pixelformat == f->fmt.sdr.pixelformat)
                        break;
        }

        if (i == ARRAY_SIZE(formats))
                i = 0;          /* Set the 1st format as default on no match */

        sdr->fmt = &formats[i];
        f->fmt.sdr.pixelformat = sdr->fmt->pixelformat;
        f->fmt.sdr.buffersize = formats[i].buffersize;
        memset(f->fmt.sdr.reserved, 0, sizeof(f->fmt.sdr.reserved));

        /*
         * If a format demands one channel only out of two
         * enabled channels, pick the 0th channel.
         */
        if (formats[i].num_ch < sdr->num_hw_ch) {
                sdr->cur_ch_mask = BIT(0);
                sdr->num_cur_ch = formats[i].num_ch;
        } else {
                sdr->cur_ch_mask = sdr->hw_ch_mask;
                sdr->num_cur_ch = sdr->num_hw_ch;
        }

        rdrif_dbg(sdr, "cur: idx %u mask %lu num %u\n",
                  i, sdr->cur_ch_mask, sdr->num_cur_ch);

        return 0;
}

static int rcar_drif_try_fmt_sdr_cap(struct file *file, void *priv,
                                     struct v4l2_format *f)
{
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(formats); i++) {
                if (formats[i].pixelformat == f->fmt.sdr.pixelformat) {
                        f->fmt.sdr.buffersize = formats[i].buffersize;
                        return 0;
                }
        }

        f->fmt.sdr.pixelformat = formats[0].pixelformat;
        f->fmt.sdr.buffersize = formats[0].buffersize;
        memset(f->fmt.sdr.reserved, 0, sizeof(f->fmt.sdr.reserved));

        return 0;
}

/* Tuner subdev ioctls */
static int rcar_drif_enum_freq_bands(struct file *file, void *priv,
                                     struct v4l2_frequency_band *band)
{
        struct rcar_drif_sdr *sdr = video_drvdata(file);

        return v4l2_subdev_call(sdr->ep.subdev, tuner, enum_freq_bands, band);
}

static int rcar_drif_g_frequency(struct file *file, void *priv,
                                 struct v4l2_frequency *f)
{
        struct rcar_drif_sdr *sdr = video_drvdata(file);

        return v4l2_subdev_call(sdr->ep.subdev, tuner, g_frequency, f);

}

static int rcar_drif_s_frequency(struct file *file, void *priv,
                                 const struct v4l2_frequency *f)
{
        struct rcar_drif_sdr *sdr = video_drvdata(file);

        return v4l2_subdev_call(sdr->ep.subdev, tuner, s_frequency, f);
}

static int rcar_drif_g_tuner(struct file *file, void *priv,
                             struct v4l2_tuner *vt)
{
        struct rcar_drif_sdr *sdr = video_drvdata(file);

        return v4l2_subdev_call(sdr->ep.subdev, tuner, g_tuner, vt);
}

static int rcar_drif_s_tuner(struct file *file, void *priv,
                             const struct v4l2_tuner *vt)
{
        struct rcar_drif_sdr *sdr = video_drvdata(file);

        return v4l2_subdev_call(sdr->ep.subdev, tuner, s_tuner, vt);
}

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 int rcar_drif_sdr_register(struct rcar_drif_sdr *sdr)
{
        int ret;

        /* Init video_device structure */
        sdr->vdev = video_device_alloc();
        if (!sdr->vdev)
                return -ENOMEM;

        snprintf(sdr->vdev->name, sizeof(sdr->vdev->name), "R-Car DRIF");
        sdr->vdev->fops = &rcar_drif_fops;
        sdr->vdev->ioctl_ops = &rcar_drif_ioctl_ops;
        sdr->vdev->release = video_device_release;
        sdr->vdev->lock = &sdr->v4l2_mutex;
        sdr->vdev->queue = &sdr->vb_queue;
        sdr->vdev->queue->lock = &sdr->vb_queue_mutex;
        sdr->vdev->ctrl_handler = &sdr->ctrl_hdl;
        sdr->vdev->v4l2_dev = &sdr->v4l2_dev;
        sdr->vdev->device_caps = V4L2_CAP_SDR_CAPTURE | V4L2_CAP_TUNER |
                V4L2_CAP_STREAMING | V4L2_CAP_READWRITE;
        video_set_drvdata(sdr->vdev, sdr);

        /* Register V4L2 SDR device */
        ret = video_register_device(sdr->vdev, VFL_TYPE_SDR, -1);
        if (ret) {
                video_device_release(sdr->vdev);
                sdr->vdev = NULL;
                dev_err(sdr->dev, "failed video_register_device (%d)\n", ret);
        }

        return ret;
}

static void rcar_drif_sdr_unregister(struct rcar_drif_sdr *sdr)
{
        video_unregister_device(sdr->vdev);
        sdr->vdev = NULL;
}

/* Sub-device bound callback */
static int rcar_drif_notify_bound(struct v4l2_async_notifier *notifier,
                                   struct v4l2_subdev *subdev,
                                   struct v4l2_async_subdev *asd)
{
        struct rcar_drif_sdr *sdr =
                container_of(notifier, struct rcar_drif_sdr, notifier);

        if (sdr->ep.asd.match.fwnode !=
            of_fwnode_handle(subdev->dev->of_node)) {
                rdrif_err(sdr, "subdev %s cannot bind\n", subdev->name);
                return -EINVAL;
        }

        v4l2_set_subdev_hostdata(subdev, sdr);
        sdr->ep.subdev = subdev;
        rdrif_dbg(sdr, "bound asd %s\n", subdev->name);

        return 0;
}

/* Sub-device unbind callback */
static void rcar_drif_notify_unbind(struct v4l2_async_notifier *notifier,
                                   struct v4l2_subdev *subdev,
                                   struct v4l2_async_subdev *asd)
{
        struct rcar_drif_sdr *sdr =
                container_of(notifier, struct rcar_drif_sdr, notifier);

        if (sdr->ep.subdev != subdev) {
                rdrif_err(sdr, "subdev %s is not bound\n", subdev->name);
                return;
        }

        /* Free ctrl handler if initialized */
        v4l2_ctrl_handler_free(&sdr->ctrl_hdl);
        sdr->v4l2_dev.ctrl_handler = NULL;
        sdr->ep.subdev = NULL;

        rcar_drif_sdr_unregister(sdr);
        rdrif_dbg(sdr, "unbind asd %s\n", subdev->name);
}

/* Sub-device registered notification callback */
static int rcar_drif_notify_complete(struct v4l2_async_notifier *notifier)
{
        struct rcar_drif_sdr *sdr =
                container_of(notifier, struct rcar_drif_sdr, notifier);
        int ret;

        /*
         * The subdev tested at this point uses 4 controls. Using 10 as a worst
         * case scenario hint. When less controls are needed there will be some
         * unused memory and when more controls are needed the framework uses
         * hash to manage controls within this number.
         */
        ret = v4l2_ctrl_handler_init(&sdr->ctrl_hdl, 10);
        if (ret)
                return -ENOMEM;

        sdr->v4l2_dev.ctrl_handler = &sdr->ctrl_hdl;
        ret = v4l2_device_register_subdev_nodes(&sdr->v4l2_dev);
        if (ret) {
                rdrif_err(sdr, "failed: register subdev nodes ret %d\n", ret);
                goto error;
        }

        ret = v4l2_ctrl_add_handler(&sdr->ctrl_hdl,
                                    sdr->ep.subdev->ctrl_handler, NULL, true);
        if (ret) {
                rdrif_err(sdr, "failed: ctrl add hdlr ret %d\n", ret);
                goto error;
        }

        ret = rcar_drif_sdr_register(sdr);
        if (ret)
                goto error;

        return ret;

error:
        v4l2_ctrl_handler_free(&sdr->ctrl_hdl);

        return ret;
}

static const struct v4l2_async_notifier_operations rcar_drif_notify_ops = {
        .bound = rcar_drif_notify_bound,
        .unbind = rcar_drif_notify_unbind,
        .complete = rcar_drif_notify_complete,
};

/* Read endpoint properties */
static void rcar_drif_get_ep_properties(struct rcar_drif_sdr *sdr,
                                        struct fwnode_handle *fwnode)
{
        u32 val;

        /* Set the I2S defaults for SIRMDR1*/
        sdr->mdr1 = RCAR_DRIF_SIRMDR1_SYNCMD_LR | RCAR_DRIF_SIRMDR1_MSB_FIRST |
                RCAR_DRIF_SIRMDR1_DTDL_1 | RCAR_DRIF_SIRMDR1_SYNCDL_0;

        /* Parse sync polarity from endpoint */
        if (!fwnode_property_read_u32(fwnode, "sync-active", &val))
                sdr->mdr1 |= val ? RCAR_DRIF_SIRMDR1_SYNCAC_POL_HIGH :
                        RCAR_DRIF_SIRMDR1_SYNCAC_POL_LOW;
        else
                sdr->mdr1 |= RCAR_DRIF_SIRMDR1_SYNCAC_POL_HIGH; /* default */

        dev_dbg(sdr->dev, "mdr1 0x%08x\n", sdr->mdr1);
}

/* Parse sub-devs (tuner) to find a matching device */
static int rcar_drif_parse_subdevs(struct rcar_drif_sdr *sdr)
{
        struct v4l2_async_notifier *notifier = &sdr->notifier;
        struct fwnode_handle *fwnode, *ep;
        int ret;

        v4l2_async_notifier_init(notifier);

        ep = fwnode_graph_get_next_endpoint(of_fwnode_handle(sdr->dev->of_node),
                                            NULL);
        if (!ep)
                return 0;

        fwnode = fwnode_graph_get_remote_port_parent(ep);
        if (!fwnode) {
                dev_warn(sdr->dev, "bad remote port parent\n");
                fwnode_handle_put(ep);
                return -EINVAL;
        }

        sdr->ep.asd.match.fwnode = fwnode;
        sdr->ep.asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
        ret = v4l2_async_notifier_add_subdev(notifier, &sdr->ep.asd);
        if (ret) {
                fwnode_handle_put(fwnode);
                return ret;
        }

        /* Get the endpoint properties */
        rcar_drif_get_ep_properties(sdr, ep);

        fwnode_handle_put(fwnode);
        fwnode_handle_put(ep);

        return 0;
}

/* Check if the given device is the primary bond */
static bool rcar_drif_primary_bond(struct platform_device *pdev)
{
        return of_property_read_bool(pdev->dev.of_node, "renesas,primary-bond");
}

/* Check if both devices of the bond are enabled */
static struct device_node *rcar_drif_bond_enabled(struct platform_device *p)
{
        struct device_node *np;

        np = of_parse_phandle(p->dev.of_node, "renesas,bonding", 0);
        if (np && of_device_is_available(np))
                return np;

        return NULL;
}

/* Check if the bonded device is probed */
static int rcar_drif_bond_available(struct rcar_drif_sdr *sdr,
                                    struct device_node *np)
{
        struct platform_device *pdev;
        struct rcar_drif *ch;
        int ret = 0;

        pdev = of_find_device_by_node(np);
        if (!pdev) {
                dev_err(sdr->dev, "failed to get bonded device from node\n");
                return -ENODEV;
        }

        device_lock(&pdev->dev);
        ch = platform_get_drvdata(pdev);
        if (ch) {
                /* Update sdr data in the bonded device */
                ch->sdr = sdr;

                /* Update sdr with bonded device data */
                sdr->ch[ch->num] = ch;
                sdr->hw_ch_mask |= BIT(ch->num);
        } else {
                /* Defer */
                dev_info(sdr->dev, "defer probe\n");
                ret = -EPROBE_DEFER;
        }
        device_unlock(&pdev->dev);

        put_device(&pdev->dev);

        return ret;
}

/* V4L2 SDR device probe */
static int rcar_drif_sdr_probe(struct rcar_drif_sdr *sdr)
{
        int ret;

        /* Validate any supported format for enabled channels */
        ret = rcar_drif_set_default_format(sdr);
        if (ret) {
                dev_err(sdr->dev, "failed to set default format\n");
                return ret;
        }

        /* Set defaults */
        sdr->hwbuf_size = RCAR_DRIF_DEFAULT_HWBUF_SIZE;

        mutex_init(&sdr->v4l2_mutex);
        mutex_init(&sdr->vb_queue_mutex);
        spin_lock_init(&sdr->queued_bufs_lock);
        spin_lock_init(&sdr->dma_lock);
        INIT_LIST_HEAD(&sdr->queued_bufs);

        /* Init videobuf2 queue structure */
        sdr->vb_queue.type = V4L2_BUF_TYPE_SDR_CAPTURE;
        sdr->vb_queue.io_modes = VB2_READ | VB2_MMAP | VB2_DMABUF;
        sdr->vb_queue.drv_priv = sdr;
        sdr->vb_queue.buf_struct_size = sizeof(struct rcar_drif_frame_buf);
        sdr->vb_queue.ops = &rcar_drif_vb2_ops;
        sdr->vb_queue.mem_ops = &vb2_vmalloc_memops;
        sdr->vb_queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;

        /* Init videobuf2 queue */
        ret = vb2_queue_init(&sdr->vb_queue);
        if (ret) {
                dev_err(sdr->dev, "failed: vb2_queue_init ret %d\n", ret);
                return ret;
        }

        /* Register the v4l2_device */
        ret = v4l2_device_register(sdr->dev, &sdr->v4l2_dev);
        if (ret) {
                dev_err(sdr->dev, "failed: v4l2_device_register ret %d\n", ret);
                return ret;
        }

        /*
         * Parse subdevs after v4l2_device_register because if the subdev
         * is already probed, bound and complete will be called immediately
         */
        ret = rcar_drif_parse_subdevs(sdr);
        if (ret)
                goto error;

        sdr->notifier.ops = &rcar_drif_notify_ops;

        /* Register notifier */
        ret = v4l2_async_notifier_register(&sdr->v4l2_dev, &sdr->notifier);
        if (ret < 0) {
                dev_err(sdr->dev, "failed: notifier register ret %d\n", ret);
                goto cleanup;
        }

        return ret;

cleanup:
        v4l2_async_notifier_cleanup(&sdr->notifier);
error:
        v4l2_device_unregister(&sdr->v4l2_dev);

        return ret;
}

/* V4L2 SDR device remove */
static void rcar_drif_sdr_remove(struct rcar_drif_sdr *sdr)
{
        v4l2_async_notifier_unregister(&sdr->notifier);
        v4l2_async_notifier_cleanup(&sdr->notifier);
        v4l2_device_unregister(&sdr->v4l2_dev);
}

/* DRIF channel probe */
static int rcar_drif_probe(struct platform_device *pdev)
{
        struct rcar_drif_sdr *sdr;
        struct device_node *np;
        struct rcar_drif *ch;
        struct resource *res;
        int ret;

        /* Reserve memory for enabled channel */
        ch = devm_kzalloc(&pdev->dev, sizeof(*ch), GFP_KERNEL);
        if (!ch)
                return -ENOMEM;

        ch->pdev = pdev;

        /* Module clock */
        ch->clk = devm_clk_get(&pdev->dev, "fck");
        if (IS_ERR(ch->clk)) {
                ret = PTR_ERR(ch->clk);
                dev_err(&pdev->dev, "clk get failed (%d)\n", ret);
                return ret;
        }

        /* Register map */
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        ch->base = devm_ioremap_resource(&pdev->dev, res);
        if (IS_ERR(ch->base))
                return PTR_ERR(ch->base);

        ch->start = res->start;
        platform_set_drvdata(pdev, ch);

        /* Check if both channels of the bond are enabled */
        np = rcar_drif_bond_enabled(pdev);
        if (np) {
                /* Check if current channel acting as primary-bond */
                if (!rcar_drif_primary_bond(pdev)) {
                        ch->num = 1;    /* Primary bond is channel 0 always */
                        of_node_put(np);
                        return 0;
                }
        }

        /* Reserve memory for SDR structure */
        sdr = devm_kzalloc(&pdev->dev, sizeof(*sdr), GFP_KERNEL);
        if (!sdr) {
                of_node_put(np);
                return -ENOMEM;
        }
        ch->sdr = sdr;
        sdr->dev = &pdev->dev;

        /* Establish links between SDR and channel(s) */
        sdr->ch[ch->num] = ch;
        sdr->hw_ch_mask = BIT(ch->num);
        if (np) {
                /* Check if bonded device is ready */
                ret = rcar_drif_bond_available(sdr, np);
                of_node_put(np);
                if (ret)
                        return ret;
        }
        sdr->num_hw_ch = hweight_long(sdr->hw_ch_mask);

        return rcar_drif_sdr_probe(sdr);
}

/* DRIF channel remove */
static int rcar_drif_remove(struct platform_device *pdev)
{
        struct rcar_drif *ch = platform_get_drvdata(pdev);
        struct rcar_drif_sdr *sdr = ch->sdr;

        /* Channel 0 will be the SDR instance */
        if (ch->num)
                return 0;

        /* SDR instance */
        rcar_drif_sdr_remove(sdr);

        return 0;
}

/* FIXME: Implement suspend/resume support */
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");
MODULE_AUTHOR("Ramesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com>");