Hi Ramesh, Thank you for the patch. On Tuesday 07 Feb 2017 15:02:37 Ramesh Shanmugasundaram wrote: > 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@xxxxxxxxxxxxxx> > --- > drivers/media/platform/Kconfig | 25 + > drivers/media/platform/Makefile | 1 + > drivers/media/platform/rcar_drif.c | 1534 +++++++++++++++++++++++++++++++++ > 3 files changed, 1560 insertions(+) > create mode 100644 drivers/media/platform/rcar_drif.c [snip] > diff --git a/drivers/media/platform/rcar_drif.c > b/drivers/media/platform/rcar_drif.c new file mode 100644 > index 0000000..88950e3 > --- /dev/null > +++ b/drivers/media/platform/rcar_drif.c > @@ -0,0 +1,1534 @@ [snip] > +/* > + * 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 Digitial Radio s/Digitial/Digital/ > + * 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. > + * > + * 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. > + */ [snip] > +#define to_rcar_drif_buf_pair(sdr, ch_num, > idx) (sdr->ch[!(ch_num)]->buf[idx]) You should enclose both sdr and idx in parenthesis, as they can be expressions. > + > +#define for_each_rcar_drif_channel(ch, ch_mask) \ > + for_each_set_bit(ch, ch_mask, RCAR_DRIF_MAX_CHANNEL) > + > +static const unsigned int num_hwbufs = 32; Is there a specific reason to make this a static const instead of a #define ? > +/* Debug */ > +static unsigned int debug; > +module_param(debug, uint, 0644); > +MODULE_PARM_DESC(debug, "activate debug info"); > + > +#define rdrif_dbg(level, sdr, fmt, arg...) \ > + v4l2_dbg(level, debug, &sdr->v4l2_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 wdlen; > + u32 num_ch; > +}; > + > +/* Format descriptions for capture */ > +static const struct rcar_drif_format formats[] = { > + { > + .pixelformat = V4L2_SDR_FMT_PCU16BE, > + .buffersize = RCAR_SDR_BUFFER_SIZE, > + .wdlen = 16, > + .num_ch = 2, How about aligning the = as in the other lines ? num_ch is always set to 2. Should we remove it for now, and add it back later when we'll support single-channel formats ? I think we should avoid carrying dead code. > + }, > + { > + .pixelformat = V4L2_SDR_FMT_PCU18BE, > + .buffersize = RCAR_SDR_BUFFER_SIZE, > + .wdlen = 18, > + .num_ch = 2, > + }, > + { > + .pixelformat = V4L2_SDR_FMT_PCU20BE, > + .buffersize = RCAR_SDR_BUFFER_SIZE, > + .wdlen = 20, > + .num_ch = 2, > + }, > +}; > + > +static const unsigned int NUM_FORMATS = ARRAY_SIZE(formats); Same question here, can't this be a define ? I think I'd even avoid NUM_FORMATS completely and use ARRAY_SIZE(formats) directly in the code, to make the boundary check more explicit when iterating over the array. > + > +/* 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; > +}; > + > +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 */ > + 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 *clkp; /* Module clock */ > + struct rcar_drif_hwbuf *buf[RCAR_DRIF_MAX_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 */ > + > + 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) */ > + > + /* Current V4L2 SDR format array index */ > + unsigned int fmt_idx; Instead of storing the index I would store a pointer to the corresponding rcar_drif_format, looking up information about the current format will then be easier. > + > + /* 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 */ > +}; > + > +/* Allocate buffer context */ > +static int rcar_drif_alloc_bufctxt(struct rcar_drif_sdr *sdr) > +{ > + struct rcar_drif_hwbuf *bufctx; > + unsigned int i, idx; > + > + for_each_rcar_drif_channel(i, &sdr->cur_ch_mask) { > + bufctx = kcalloc(num_hwbufs, sizeof(*bufctx), GFP_KERNEL); How about embedding the buffer contexts in the rcar_drif structure instead of just storing pointers there ? The rcar_drif_hwbuf structure is pretty small, it won't make a big difference, and will simplify the code. > + if (!bufctx) > + return -ENOMEM; > + > + for (idx = 0; idx < num_hwbufs; idx++) > + sdr->ch[i]->buf[idx] = bufctx + idx; > + } > + return 0; > +} [snip] > +/* Release DMA channel */ > +static void rcar_drif_release_dmachannel(struct rcar_drif_sdr *sdr) I would name the function rcar_drif_release_dma_channels as it handles all channels. Same for rcar_drif_alloc_dma_channels. > +{ > + 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 channel */ > +static int rcar_drif_alloc_dmachannel(struct rcar_drif_sdr *sdr) > +{ > + struct dma_slave_config dma_cfg; > + unsigned int i; > + int ret = -ENODEV; > + > + for_each_rcar_drif_channel(i, &sdr->cur_ch_mask) { > + struct rcar_drif *ch = sdr->ch[i]; > + > + ch->dmach = dma_request_slave_channel(&ch->pdev->dev, "rx"); > + if (!ch->dmach) { > + rdrif_err(sdr, "ch%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->start + RCAR_DRIF_SIRFDR); > + dma_cfg.dst_addr = 0; This isn't needed as you memset the whole structure to 0. > + 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_dmachannel(sdr); > + return ret; > +} [snip] > +/* 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 */ > + writel(RCAR_DRIF_SITMDR1_PCON, > + sdr->ch[i]->base + RCAR_DRIF_SITMDR1); I would create a rcar_drif_write(struct rcar_drif *ch, u32 offset, u32 data) function, the code will become clearer. Same for the read operation. > + /* Setup MDR1 value */ > + writel(sdr->mdr1, sdr->ch[i]->base + RCAR_DRIF_SIRMDR1); > + > + rdrif_dbg(2, sdr, "ch%u: mdr1 = 0x%08x", > + i, readl(sdr->ch[i]->base + RCAR_DRIF_SIRMDR1)); Once you've debugged the driver I'm not sure those debugging statements are still needed. > + } > +} > + > +/* Extract bitlen and wdcnt from given word length */ > +static int rcar_drif_convert_wdlen(struct rcar_drif_sdr *sdr, > + u32 wdlen, u32 *bitlen, u32 *wdcnt) > +{ > + unsigned int 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; Can't you store the bitlen and wdcnt values in the rcar_drif_format structure instead of recomputing them every time ? > + break; > + } > + } > + > + /* Sanity check range */ > + if (i == 32 || !(*bitlen >= 8 && *bitlen <= 32) || > + !(*wdcnt >= 1 && *wdcnt <= 64)) { > + rdrif_err(sdr, "invalid wdlen %u configured\n", wdlen); > + return -EINVAL; You shouldn't have invalid wdlen values in the driver. I would remove this check as it makes error handling in the caller more complex. > + } > + > + return 0; > +} > + > +/* Set DRIF receive format */ > +static int rcar_drif_set_format(struct rcar_drif_sdr *sdr) > +{ > + u32 bitlen, wdcnt, wdlen; > + unsigned int i; > + int ret = -EINVAL; > + > + wdlen = formats[sdr->fmt_idx].wdlen; > + rdrif_dbg(2, sdr, "setfmt: idx %u, wdlen %u, num_ch %u\n", > + sdr->fmt_idx, wdlen, formats[sdr->fmt_idx].num_ch); > + > + /* Sanity check */ > + if (formats[sdr->fmt_idx].num_ch > sdr->num_cur_ch) { > + rdrif_err(sdr, "fmt idx %u current ch %u mismatch\n", > + sdr->fmt_idx, sdr->num_cur_ch); > + return ret; This should never happen, it should be caught at set format time. > + } > + > + /* Get bitlen & wdcnt from wdlen */ > + ret = rcar_drif_convert_wdlen(sdr, wdlen, &bitlen, &wdcnt); > + if (ret) > + return ret; > + > + /* 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(bitlen) | > + RCAR_DRIF_MDR_WDCNT(wdcnt); > + writel(mdr, sdr->ch[i]->base + RCAR_DRIF_SIRMDR2); > + > + mdr = RCAR_DRIF_MDR_BITLEN(bitlen) | RCAR_DRIF_MDR_WDCNT(wdcnt); > + writel(mdr, sdr->ch[i]->base + RCAR_DRIF_SIRMDR3); > + > + rdrif_dbg(2, sdr, "ch%u: new mdr[2,3] = 0x%08x, 0x%08x\n", > + i, readl(sdr->ch[i]->base + RCAR_DRIF_SIRMDR2), > + readl(sdr->ch[i]->base + RCAR_DRIF_SIRMDR3)); > + } > + return ret; > +} > + > +/* 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] && ch->buf[0]->addr) { > + dma_free_coherent(&ch->pdev->dev, > + sdr->hwbuf_size * 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 * num_hwbufs, > + &ch->dma_handle, GFP_KERNEL); > + if (!addr) { > + rdrif_err(sdr, > + "ch%u: dma alloc failed. num_hwbufs %u size %u\n", > + i, num_hwbufs, sdr->hwbuf_size); > + goto alloc_error; > + } > + > + /* Split the chunk and populate bufctxt */ > + for (j = 0; j < num_hwbufs; j++) { > + ch->buf[j]->addr = addr + (j * sdr->hwbuf_size); > + ch->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_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(formats[sdr->fmt_idx].buffersize); > + > + rdrif_dbg(2, 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(2, 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(1, sdr, "\napp late: prod %u\n", sdr->produced); > + sdr->produced++; /* Increment the produced count anyway */ > + spin_unlock_irqrestore(&sdr->queued_bufs_lock, flags); > + return NULL; > + } > + list_del(&fbuf->list); > + spin_unlock_irqrestore(&sdr->queued_bufs_lock, flags); > + > + return fbuf; > +} > + > +static inline bool rcar_drif_buf_pairs_done(struct rcar_drif_hwbuf *buf1, > + struct rcar_drif_hwbuf *buf2) > +{ > + return (buf1->status & buf2->status & RCAR_DRIF_BUF_DONE); > +} > + > +/* 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 = readl(ch->base + RCAR_DRIF_SISTR); > + if (unlikely(str & RCAR_DRIF_RFOVF)) { > + /* Writing the same clears it */ > + writel(str, ch->base + RCAR_DRIF_SISTR); > + > + /* Overflow: some samples are lost */ > + ch->buf[idx]->status |= RCAR_DRIF_BUF_OVERFLOW; > + } > +} > + > +/* Deliver buffer to user */ > +static void rcar_drif_deliver_buf(struct rcar_drif *ch) > +{ > + struct rcar_drif_sdr *sdr = ch->sdr; > + u32 idx = sdr->produced % num_hwbufs; > + struct rcar_drif_frame_buf *fbuf; > + bool overflow = false; > + > + rcar_drif_channel_complete(ch, idx); > + > + if (sdr->num_cur_ch == RCAR_DRIF_MAX_CHANNEL) { > + struct rcar_drif_hwbuf *bufi, *bufq; > + > + if (ch->num) { > + bufi = to_rcar_drif_buf_pair(sdr, ch->num, idx); > + bufq = ch->buf[idx]; > + } else { > + bufi = ch->buf[idx]; > + bufq = to_rcar_drif_buf_pair(sdr, ch->num, idx); > + } > + > + /* Check if both DMA buffers are done */ > + if (!rcar_drif_buf_pairs_done(bufi, bufq)) > + return; > + > + /* Clear buf done status */ > + bufi->status &= ~RCAR_DRIF_BUF_DONE; > + bufq->status &= ~RCAR_DRIF_BUF_DONE; > + > + /* Get fbuf */ > + fbuf = rcar_drif_get_fbuf(sdr); > + if (!fbuf) > + return; > + > + memcpy(vb2_plane_vaddr(&fbuf->vb.vb2_buf, 0), > + bufi->addr, sdr->hwbuf_size); > + memcpy(vb2_plane_vaddr(&fbuf->vb.vb2_buf, 0) + sdr- >hwbuf_size, > + bufq->addr, sdr->hwbuf_size); Ouch ! That's a high data rate memcpy that can be avoided. Why don't you DMA directly to the vb2 buffers ? You will need to use videobuf2-dma-contig instead of videobuf2-vmalloc, but apart from that there should be no issue. > + if ((bufi->status | bufq->status) & RCAR_DRIF_BUF_OVERFLOW) { > + overflow = true; > + /* Clear the flag in status */ > + bufi->status &= ~RCAR_DRIF_BUF_OVERFLOW; > + bufq->status &= ~RCAR_DRIF_BUF_OVERFLOW; > + } > + } else { > + struct rcar_drif_hwbuf *bufiq; > + > + /* Get fbuf */ > + fbuf = rcar_drif_get_fbuf(sdr); > + if (!fbuf) > + return; > + > + bufiq = ch->buf[idx]; > + > + memcpy(vb2_plane_vaddr(&fbuf->vb.vb2_buf, 0), > + bufiq->addr, sdr->hwbuf_size); > + > + if (bufiq->status & RCAR_DRIF_BUF_OVERFLOW) { > + overflow = true; > + /* Clear the flag in status */ > + bufiq->status &= ~RCAR_DRIF_BUF_OVERFLOW; > + } > + } > + > + rdrif_dbg(2, sdr, "ch%u: prod %u\n", ch->num, sdr->produced); > + > + fbuf->vb.field = V4L2_FIELD_NONE; > + fbuf->vb.sequence = sdr->produced++; > + fbuf->vb.vb2_buf.timestamp = ktime_get_ns(); > + vb2_set_plane_payload(&fbuf->vb.vb2_buf, 0, > + formats[sdr->fmt_idx].buffersize); > + > + /* Set error state on overflow */ > + 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); Maybe vb2_buffer_done(&fbuf->vb.vb2_buf, overflow ? VB2_BUF_STATE_ERROR: VB2_BUF_STATE_DONE); > +} > + > +/* 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; > + > + mutex_lock(&sdr->vb_queue_mutex); Isn't the complete callback potentially called in interrupt context ? I know the rcar-dmac driver uses a threaded interrupt handler for that, but is that a guarantee of the DMA engine API ? > + > + /* DMA can be terminated while the callback was waiting on lock */ > + if (!vb2_is_streaming(&sdr->vb_queue)) Can it ? The streaming flag is cleared after the stop_streaming operation is called, which will terminate all DMA transfers synchronously. > + goto stopped; > + > + rcar_drif_deliver_buf(ch); > +stopped: > + mutex_unlock(&sdr->vb_queue_mutex); > +} > + > +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 * 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; > + > + /* > + * 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 = readl(sdr->ch[i]->base + RCAR_DRIF_SICTR); > + ctr |= (RCAR_DRIF_SICTR_RX_RISING_EDGE | > + RCAR_DRIF_SICTR_RX_EN); > + writel(ctr, sdr->ch[i]->base + RCAR_DRIF_SICTR); > + } > + > + /* 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, > + 2, 500000); A 2µs sleep for a 500ms total timeout seems very low to me, that will stress the CPU. Same comment for the other locations where you use readl_poll_timeout. How long does the channel typically take to get enabled ? > + if (ret) { > + rdrif_err(sdr, "ch%u: rx en failed. ctr 0x%08x\n", > + i, readl(sdr->ch[i]->base + 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 = readl(sdr->ch[i]->base + RCAR_DRIF_SICTR); > + ctr &= ~RCAR_DRIF_SICTR_RX_EN; > + writel(ctr, sdr->ch[i]->base + RCAR_DRIF_SICTR); > + } > + > + /* 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), > + 2, 500000); How long does the channel typically take to get disabled ? > + if (ret) > + dev_warn(&sdr->vdev->dev, > + "ch%u: failed to disable rx. ctr 0x%08x\n", > + i, readl(sdr->ch[i]->base + RCAR_DRIF_SICTR)); > + } > +} > + > +/* 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 */ > + writel(RCAR_DRIF_SICTR_RESET, ch->base + RCAR_DRIF_SICTR); > + ret = readl_poll_timeout(ch->base + RCAR_DRIF_SICTR, > + ctr, !(ctr & RCAR_DRIF_SICTR_RESET), The alignment is weird. > + 2, 500000); > + if (ret) { > + rdrif_err(sdr, "ch%u: failed to reset rx. ctr 0x%08x\n", > + ch->num, readl(ch->base + 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; > + writel(str, ch->base + RCAR_DRIF_SISTR); > + > + /* Enable DMA receive interrupt */ > + writel(0x00009000, ch->base + RCAR_DRIF_SIIER); > + > + return ret; > +} > + > +/* Start receive operation */ > +static int rcar_drif_start(struct rcar_drif_sdr *sdr) > +{ > + 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; > + } > + > + sdr->produced = 0; > + ret = rcar_drif_enable_rx(sdr); > +start_error: Don't you need to stop the channels that were successfully started if an error occurs ? > + return ret; > +} > + > +/* Stop channel */ > +static void rcar_drif_stop_channel(struct rcar_drif *ch) > +{ > + struct rcar_drif_sdr *sdr = ch->sdr; > + int ret, retries = 3; > + > + /* Disable DMA receive interrupt */ > + writel(0x00000000, ch->base + RCAR_DRIF_SIIER); > + > + do { > + /* Terminate all DMA transfers */ > + ret = dmaengine_terminate_sync(ch->dmach); > + if (!ret) > + break; > + rdrif_dbg(2, sdr, "stop retry\n"); > + } while (--retries); Why do you need to retry the terminate operation, why does it fail ? > + WARN_ON(!retries); > +} [snip] > +/* 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 int i, j; > + int ret; > + > + mutex_lock(&sdr->v4l2_mutex); I'm surprised, aren't the start_streaming and stop_streaming operations called with the video device lock held already by the v4l2-ioctl layer ? I think they should be, if they're not there's probably a bug somewhere. > + for_each_rcar_drif_channel(i, &sdr->cur_ch_mask) { > + ret = clk_prepare_enable(sdr->ch[i]->clkp); > + if (ret) > + goto start_error; > + } > + > + /* Set default MDRx settings */ > + rcar_drif_set_mdr1(sdr); > + > + /* Set new format */ > + ret = rcar_drif_set_format(sdr); > + if (ret) > + goto start_error; > + > + if (sdr->num_cur_ch == RCAR_DRIF_MAX_CHANNEL) > + sdr->hwbuf_size = > + formats[sdr->fmt_idx].buffersize / RCAR_DRIF_MAX_CHANNEL; > + else > + sdr->hwbuf_size = formats[sdr->fmt_idx].buffersize; > + > + rdrif_dbg(1, sdr, "num_hwbufs %u, hwbuf_size %u\n", > + num_hwbufs, sdr->hwbuf_size); > + > + /* Alloc DMA channel */ > + ret = rcar_drif_alloc_dmachannel(sdr); > + if (ret) > + goto start_error; > + > + /* Alloc buf context */ > + ret = rcar_drif_alloc_bufctxt(sdr); > + if (ret) > + goto start_error; > + > + /* Request buffers */ > + ret = rcar_drif_request_buf(sdr); > + if (ret) > + goto start_error; > + > + /* Start Rx */ > + ret = rcar_drif_start(sdr); > + if (ret) > + goto start_error; > + > + mutex_unlock(&sdr->v4l2_mutex); > + rdrif_dbg(1, sdr, "started\n"); > + return ret; > + > +start_error: As there's a single error label I would call this "error". Up to you. > + rcar_drif_release_queued_bufs(sdr, VB2_BUF_STATE_QUEUED); > + rcar_drif_release_buf(sdr); > + rcar_drif_release_bufctxt(sdr); > + rcar_drif_release_dmachannel(sdr); > + for (j = 0; j < i; j++) > + clk_disable_unprepare(sdr->ch[j]->clkp); > + > + mutex_unlock(&sdr->v4l2_mutex); > + return ret; > +} [snip] > +/* Vb2 ops */ > +static struct vb2_ops rcar_drif_vb2_ops = { You can make this static const. > + .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, > +}; [snip] > +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); > + > + f->fmt.sdr.pixelformat = formats[sdr->fmt_idx].pixelformat; > + f->fmt.sdr.buffersize = formats[sdr->fmt_idx].buffersize; > + memset(f->fmt.sdr.reserved, 0, sizeof(f->fmt.sdr.reserved)); I believe the core ioctl handling code already does this for you. Same for the other ioctl handlers in > + 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; > + > + 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) { The code would become more readable (at least in my opinion) if you just added a break here, and moved the code below after the loop. In case the requested format isn't found (i == NUM_FORMATS) you can then set i to 0 and proceed, that will select the first available format as a default. > + sdr->fmt_idx = i; > + f->fmt.sdr.buffersize = formats[i].buffersize; > + > + /* > + * 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(1, sdr, "cur: idx %u mask %lu num %u\n", > + i, sdr->cur_ch_mask, sdr->num_cur_ch); > + return 0; > + } > + } > + > + if (rcar_drif_set_default_format(sdr)) { > + rdrif_err(sdr, "cannot set default format\n"); > + return -EINVAL; > + } > + > + f->fmt.sdr.pixelformat = formats[sdr->fmt_idx].pixelformat; > + f->fmt.sdr.buffersize = formats[sdr->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_sdr *sdr = video_drvdata(file); > + unsigned int 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[sdr->fmt_idx].pixelformat; > + f->fmt.sdr.buffersize = formats[sdr->fmt_idx].buffersize; The result of the TRY_FMT ioctl should not depend on the currently configured format. I would return a fixed format (for instance the first one in the formats array) in the default case. > + 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); > + struct v4l2_subdev *sd; > + int ret = 0; > + > + v4l2_device_for_each_subdev(sd, &sdr->v4l2_dev) { > + ret = v4l2_subdev_call(sd, tuner, enum_freq_bands, band); This won't work as-is when you'll have multiple subdevs. As the driver only supports a single connected subdev at the moment, I suggest storing a pointer to that subdev in the rcar_drif_sdr structure, and calling operations on that subdev explicitly instead of looping over all subdevs. The comment holds for all other ioctls. > + if (ret) > + break; > + } > + return ret; > +} [snip] > +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); > + > + /* Nothing to do at this point */ If there's nothing to do you can just leave the bound callback unimplemented, it's optional. > + rdrif_dbg(2, sdr, "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_sdr *sdr = > + container_of(notifier, struct rcar_drif_sdr, notifier); > + struct v4l2_subdev *sd; > + int ret; > + > + 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); > + return ret; > + } Do you need to expose subdev nodes to userspace ? Can't everything be handled from the V4L2 SDR node ? > + v4l2_device_for_each_subdev(sd, &sdr->v4l2_dev) { > + ret = v4l2_ctrl_add_handler(sdr->v4l2_dev.ctrl_handler, > + sd->ctrl_handler, NULL); Shouldn't you undo this somewhere when unbinding the subdevs ? > + if (ret) { > + rdrif_err(sdr, "failed ctrl add hdlr ret %d\n", ret); > + return ret; > + } > + } > + rdrif_dbg(2, sdr, "notify complete\n"); > + return 0; > +} [snip] > +/* Parse sub-devs (tuner) to find a matching device */ > +static int rcar_drif_parse_subdevs(struct rcar_drif_sdr *sdr, > + struct device *dev) > +{ > + struct v4l2_async_notifier *notifier = &sdr->notifier; > + struct rcar_drif_async_subdev *rsd; > + struct device_node *node; > + > + notifier->subdevs = devm_kzalloc(dev, sizeof(*notifier->subdevs), > + GFP_KERNEL); > + if (!notifier->subdevs) > + return -ENOMEM; > + > + node = of_graph_get_next_endpoint(dev->of_node, NULL); > + if (!node) > + return 0; > + > + rsd = devm_kzalloc(dev, sizeof(*rsd), GFP_KERNEL); > + if (!rsd) { > + of_node_put(node); If you move the allocation above of_graph_get_next_endpoint() you won't have to call of_node_put() in the error path. > + return -ENOMEM; > + } > + > + notifier->subdevs[notifier->num_subdevs] = &rsd->asd; > + rsd->asd.match.of.node = of_graph_get_remote_port_parent(node); Aren't you missing an of_node_put() on the returned node ? Or does the async framework take care of that ? > + 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++; > + > + /* Get the endpoint properties */ > + rcar_drif_get_ep_properties(sdr, node); > + return 0; > +} > + > +/* Check if the given device is the primary bond */ > +static bool rcar_drif_primary_bond(struct platform_device *pdev) > +{ > + if (of_find_property(pdev->dev.of_node, "renesas,primary-bond", NULL)) > + return true; > + > + return false; How about return of_property_read_bool(pdev->dev.of_node, "renesas,primary-bond"); > +} > + > +/* Get the bonded platform dev if enabled */ > +static struct platform_device *rcar_drif_enabled_bond(struct > platform_device *p) > +{ > + struct device_node *np; > + > + np = of_parse_phandle(p->dev.of_node, "renesas,bonding", 0); The function takes a reference to np, you need to call of_node_put() on it (only if the returned pointer isn't NULL). > + if (np && of_device_is_available(np)) > + return of_find_device_by_node(np); of_find_device_by_node() takes a reference to the returned device, you need to call device_put() on it when you don't need it anymore. > + return NULL; > +} > + > +/* Proble internal channel */ > +static int rcar_drif_channel_probe(struct platform_device *pdev) > +{ > + struct rcar_drif *ch; > + struct resource *res; > + void __iomem *base; > + struct clk *clkp; Maybe s/clkp/clk/ ? > + int ret; > + > + /* Peripheral clock */ > + clkp = devm_clk_get(&pdev->dev, "fck"); > + if (IS_ERR(clkp)) { > + ret = PTR_ERR(clkp); > + dev_err(&pdev->dev, "clk get failed (%d)\n", ret); > + return ret; > + } Isn't the clock managed automatically by runtime PM ? > + /* Register map */ > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + base = devm_ioremap_resource(&pdev->dev, res); > + if (IS_ERR(base)) { > + ret = PTR_ERR(base); > + dev_err(&pdev->dev, "ioremap failed (%d)\n", ret); > + return ret; devm_ioremap_resource() already prints an error message, you can remove this one. > + } > + > + /* Reserve memory for enabled channel */ > + ch = devm_kzalloc(&pdev->dev, sizeof(*ch), GFP_KERNEL); > + if (!ch) { > + ret = PTR_ERR(ch); > + dev_err(&pdev->dev, "failed alloc channel\n"); Memory allocation failures already print error messages, you can remove this one. > + return ret; > + } > + ch->pdev = pdev; > + ch->clkp = clkp; > + ch->base = base; > + ch->start = res->start; If you allocated the ch structure first you could set the fields directly without a need for local variables. > + platform_set_drvdata(pdev, ch); > + return 0; > +} > + > +static int rcar_drif_probe(struct platform_device *pdev) > +{ > + struct rcar_drif *ch, *b_ch = NULL; > + struct platform_device *b_pdev; > + struct rcar_drif_sdr *sdr; > + int ret; > + > + /* Probe internal channel */ > + ret = rcar_drif_channel_probe(pdev); > + if (ret) > + return ret; I would have done it the other way around, inlining the rcar_drif_channel_probe() function here as that's the common case, and moving the V4L2 SDR device initialization code to a different function. > + /* Check if both channels of the bond are enabled */ > + b_pdev = rcar_drif_enabled_bond(pdev); > + if (b_pdev) { > + /* Check if current channel acting as primary-bond */ > + if (!rcar_drif_primary_bond(pdev)) { > + dev_notice(&pdev->dev, "probed\n"); > + return 0; > + } > + > + /* Check if the other device is probed */ > + b_ch = platform_get_drvdata(b_pdev); > + if (!b_ch) { > + dev_info(&pdev->dev, "defer probe\n"); > + return -EPROBE_DEFER; > + } Isn't this all very racy ? What if the other channel's device is removed while this one is probed ? > + /* Set the other channel number */ > + b_ch->num = 1; Reading data from the other channel's private structure is one thing, but writing it makes me shiver :-S Could we make it so that 0 is the slave and 1 the master ? That way you would set ch->num = 1 instead of b_ch->num = 1, keeping all modifications to the private structure local to the device being probed. > + } > + > + /* Channel acting as SDR instance */ > + ch = platform_get_drvdata(pdev); > + ch->acting_sdr = true; > + > + /* Reserve memory for SDR structure */ > + sdr = devm_kzalloc(&pdev->dev, sizeof(*sdr), GFP_KERNEL); > + if (!sdr) { > + ret = PTR_ERR(sdr); > + dev_err(&pdev->dev, "failed alloc drif context\n"); > + return ret; > + } > + sdr->dev = &pdev->dev; > + sdr->hw_ch_mask = BIT(ch->num); > + > + /* Establish links between SDR and channel(s) */ > + ch->sdr = sdr; > + sdr->ch[ch->num] = ch; > + if (b_ch) { > + sdr->ch[b_ch->num] = b_ch; > + b_ch->sdr = sdr; > + sdr->hw_ch_mask |= BIT(b_ch->num); > + } > + sdr->num_hw_ch = hweight_long(sdr->hw_ch_mask); > + > + /* 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); > + 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, "could not initialize vb2 queue\n"); > + return ret; > + } > + > + /* Register the v4l2_device */ > + ret = v4l2_device_register(&pdev->dev, &sdr->v4l2_dev); > + if (ret) { > + dev_err(sdr->dev, "failed v4l2_device_register (%d)\n", ret); Maybe "failed to register V4L2 device" to make it a real sentence ? :-) > + 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, &pdev->dev); > + if (ret) > + goto err_unreg_v4l2; > + > + sdr->notifier.bound = rcar_drif_notify_bound; > + sdr->notifier.complete = rcar_drif_notify_complete; > + > + v4l2_ctrl_handler_init(&sdr->ctrl_hdl, 10); Possibly a stupid question, why 10, if you don't create any control in this driver ? > + /* Register notifier */ > + ret = v4l2_async_notifier_register(&sdr->v4l2_dev, &sdr->notifier); > + if (ret < 0) { > + dev_err(sdr->dev, "notifier registration failed (%d)\n", ret); > + goto err_free_ctrls; > + } > + > + /* Init video_device structure */ > + sdr->vdev = video_device_alloc(); > + if (!sdr->vdev) { > + ret = -ENOMEM; > + goto err_unreg_notif; > + } > + 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) { > + dev_err(sdr->dev, "failed video_register_device (%d)\n", ret); Same here, "failed to register video device" ? > + goto err_unreg_notif; > + } > + > + dev_notice(sdr->dev, "probed\n"); Do you think this message is really useful ? I believe it would just add a bit more noise to the kernel log, without any real use. > + return 0; > + > +err_unreg_notif: > + video_device_release(sdr->vdev); > + v4l2_async_notifier_unregister(&sdr->notifier); > +err_free_ctrls: > + v4l2_ctrl_handler_free(&sdr->ctrl_hdl); > +err_unreg_v4l2: > + v4l2_device_unregister(&sdr->v4l2_dev); > + return ret; > +} > + > +static int rcar_drif_remove(struct platform_device *pdev) > +{ > + struct rcar_drif *ch = platform_get_drvdata(pdev); > + struct rcar_drif_sdr *sdr = ch->sdr; > + > + if (!ch->acting_sdr) { Isn't it possible to check the channel number instead and remove the acting_sdr field ? > + /* Nothing to do */ > + dev_notice(&pdev->dev, "removed\n"); > + return 0; > + } > + > + /* SDR instance */ > + v4l2_ctrl_handler_free(sdr->vdev->ctrl_handler); > + v4l2_async_notifier_unregister(&sdr->notifier); > + v4l2_device_unregister(&sdr->v4l2_dev); > + video_unregister_device(sdr->vdev); > + dev_notice(&pdev->dev, "removed\n"); Even more than the probed message, I think this one can go away. > + return 0; > +} > + > +static int __maybe_unused rcar_drif_suspend(struct device *dev) > +{ > + return 0; Maybe a /* FIXME: Implement suspend/resume support */ ? > +} > + > +static int __maybe_unused rcar_drif_resume(struct device *dev) > +{ > + return 0; Same here ? > +} [snip] -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html