Re: [PATCH v2 3/4] media: misc: introduce microchip_csi2dc driver
From: Eugen.Hristev
Date: Tue Aug 25 2020 - 09:20:05 EST
On 25.08.2020 15:44, Eugen Hristev - M18282 wrote:
> On 14.08.2020 01:44, Sakari Ailus wrote:
>
>> Hi Eugen,
>>
>> Thanks for the patch.
>
> Hello Sakari,
>
> Thanks for reviewing.
>
>>
>> On Fri, Jul 03, 2020 at 10:44:15AM +0300, Eugen Hristev wrote:
>>> Microchip CSI2DC (CSI2 Demultiplexer Controller) is a misc bridge device
>>> that converts a byte stream in IDI Synopsys format (coming from a CSI2HOST)
>>> to a pixel stream that can be captured by a sensor controller.
>>>
>>> Signed-off-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>
>>> ---
>>> drivers/media/misc/Kconfig | 9 +
>>> drivers/media/misc/Makefile | 1 +
>>> drivers/media/misc/microchip_csi2dc.c | 705 ++++++++++++++++++++++++++
>>> 3 files changed, 715 insertions(+)
>>> create mode 100644 drivers/media/misc/microchip_csi2dc.c
>>>
>>> diff --git a/drivers/media/misc/Kconfig b/drivers/media/misc/Kconfig
>>> index 206f39f86f46..86e892a41eba 100644
>>> --- a/drivers/media/misc/Kconfig
>>> +++ b/drivers/media/misc/Kconfig
>>> @@ -8,6 +8,15 @@ menu "Miscellaneous helper chips"
>>>
>>> comment "Various helper chips"
>>>
>>> +config VIDEO_MICROCHIP_CSI2DC
>>> + tristate "Microchip CSI2 Demux Controller"
>>> + depends on VIDEO_V4L2
>>> + help
>>> + CSI2 Demux Controller driver. CSI2DC is a helper chip
>>> + that converts IDI interface byte stream to a parallel pixel stream.
>>> + It supports various RAW formats as input.
>>> + Performs clock domain crossing between hardware blocks.
>>> +
>>> endmenu
>>>
>>> endif
>>> diff --git a/drivers/media/misc/Makefile b/drivers/media/misc/Makefile
>>> index f66554cd5c45..86477781b7af 100644
>>> --- a/drivers/media/misc/Makefile
>>> +++ b/drivers/media/misc/Makefile
>>> @@ -1 +1,2 @@
>>> # SPDX-License-Identifier: GPL-2.0
>>> +obj-$(CONFIG_VIDEO_MICROCHIP_CSI2DC) += microchip_csi2dc.o
>>> diff --git a/drivers/media/misc/microchip_csi2dc.c b/drivers/media/misc/microchip_csi2dc.c
>>> new file mode 100644
>>> index 000000000000..494b7c137b17
>>> --- /dev/null
>>> +++ b/drivers/media/misc/microchip_csi2dc.c
>>> @@ -0,0 +1,705 @@
>>> +// SPDX-License-Identifier: GPL-2.0
>>> +/*
>>> + * Microchip CSI2 Demux Controller (CSI2DC) driver
>>> + *
>>> + * Copyright (C) 2018-2020 Microchip Technology, Inc.
>>> + *
>>> + * Author: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>
>>> + *
>>> + */
>>> +
>>> +#include <linux/clk.h>
>>> +#include <linux/module.h>
>>> +#include <linux/of.h>
>>> +#include <linux/of_graph.h>
>>> +#include <linux/platform_device.h>
>>> +#include <linux/pm_runtime.h>
>>> +#include <linux/videodev2.h>
>>> +
>>> +#include <media/v4l2-device.h>
>>> +#include <media/v4l2-fwnode.h>
>>> +#include <media/v4l2-subdev.h>
>>> +#include <media/videobuf2-dma-contig.h>
>>> +
>>> +/* Global configuration register */
>>> +#define CSI2DC_GCFG 0x0
>>> +
>>> +/* MIPI sensor pixel clock is free running */
>>> +#define CSI2DC_GCFG_MIPIFRN BIT(0)
>>> +/* Output waveform inter-line minimum delay */
>>> +#define CSI2DC_GCFG_HLC(v) ((v) << 4)
>>> +#define CSI2DC_GCFG_HLC_MASK GENMASK(7, 4)
>>> +
>>> +/* Global control register */
>>> +#define CSI2DC_GCTLR 0x04
>>> +#define CSI2DC_GCTLR_SWRST BIT(0)
>>> +
>>> +/* Global status register */
>>> +#define CSI2DC_GS 0x08
>>> +
>>> +/* SSP interrupt status register */
>>> +#define CSI2DC_SSPIS 0x28
>>> +/* Pipe update register */
>>> +#define CSI2DC_PU 0xC0
>>> +/* Video pipe attributes update */
>>> +#define CSI2DC_PU_VP BIT(0)
>>> +
>>> +/* Pipe update status register */
>>> +#define CSI2DC_PUS 0xC4
>>> +
>>> +/* Video pipeline enable register */
>>> +#define CSI2DC_VPE 0xF8
>>> +#define CSI2DC_VPE_ENABLE BIT(0)
>>> +
>>> +/* Video pipeline configuration register */
>>> +#define CSI2DC_VPCFG 0xFC
>>> +/* Data type */
>>> +#define CSI2DC_VPCFG_DT(v) ((v) << 0)
>>> +#define CSI2DC_VPCFG_DT_MASK GENMASK(5, 0)
>>> +/* Virtual channel identifier */
>>> +#define CSI2DC_VPCFG_VC(v) ((v) << 6)
>>> +#define CSI2DC_VPCFG_VC_MASK GENMASK(7, 6)
>>> +/* Decompression enable */
>>> +#define CSI2DC_VPCFG_DE BIT(8)
>>> +/* Decoder mode */
>>> +#define CSI2DC_VPCFG_DM(v) ((v) << 9)
>>> +#define CSI2DC_VPCFG_DM_DECODER8TO12 0
>>> +/* Decoder predictor 2 selection */
>>> +#define CSI2DC_VPCFG_DP2 BIT(12)
>>> +/* Recommended memory storage */
>>> +#define CSI2DC_VPCFG_RMS BIT(13)
>>> +/* Post adjustment */
>>> +#define CSI2DC_VPCFG_PA BIT(14)
>>> +
>>> +/* Video pipeline column register */
>>> +#define CSI2DC_VPCOL 0x100
>>> +/* Column number */
>>> +#define CSI2DC_VPCOL_COL(v) ((v) << 0)
>>> +#define CSI2DC_VPCOL_COL_MASK GENMASK(15, 0)
>>> +
>>> +/* Video pipeline row register */
>>> +#define CSI2DC_VPROW 0x104
>>> +/* Row number */
>>> +#define CSI2DC_VPROW_ROW(v) ((v) << 0)
>>> +#define CSI2DC_VPROW_ROW_MASK GENMASK(15, 0)
>>> +
>>> +/* Version register */
>>> +#define CSI2DC_VERSION 0x1FC
>>> +
>>> +/* register read/write helpers */
>>> +#define csi2dc_readl(st, reg) readl_relaxed((st)->base + (reg))
>>> +#define csi2dc_writel(st, reg, val) writel_relaxed((val), (st)->base + (reg))
>>> +
>>> +/* supported RAW data types */
>>> +#define CSI2DC_DT_RAW6 0x28
>>> +#define CSI2DC_DT_RAW7 0x29
>>> +#define CSI2DC_DT_RAW8 0x2A
>>> +#define CSI2DC_DT_RAW10 0x2B
>>> +#define CSI2DC_DT_RAW12 0x2C
>>> +#define CSI2DC_DT_RAW14 0x2D
>>> +
>>> +struct csi2dc_format {
>>> + u32 mbus_code;
>>> + u32 dt;
>>> +};
>>> +
>>> +static struct csi2dc_format csi2dc_formats_list[] = {
>>
>> const
>>
Hi Sakari,
Elements from this table are being pointed to dynamically by all the
other variables , like cur_fmt, try_fmt, and the dynamically built
formats list. If I make this const, I either have to propagate const to
all dynamic elements (which would not make sense, because they will keep
changing), or at some point to avoid compiler warning, cast out to non
const elements.
What do you think ?
Eugen
>>> + {
>>> + .mbus_code = MEDIA_BUS_FMT_SRGGB10_1X10,
>>> + .dt = CSI2DC_DT_RAW10,
>>> + },
>>> +};
>>> +
>>> +enum mipi_csi_pads {
>>> + CSI2DC_PAD_SINK = 0,
>>> + CSI2DC_PAD_SOURCE = 1,
>>> + CSI2DC_PADS_NUM = 2,
>>> +};
>>> +
>>> +struct csi2dc_device {
>>> + void __iomem *base;
>>> + struct v4l2_subdev csi2dc_sd;
>>> + struct device *dev;
>>> + struct v4l2_device v4l2_dev;
>>> + struct clk *pclk;
>>> + struct clk *scck;
>>> +
>>> + bool video_pipe;
>>> +
>>> + u32 num_fmts;
>>> + struct csi2dc_format **formats;
>>> +
>>> + struct csi2dc_format *cur_fmt;
>>> + struct csi2dc_format *try_fmt;
>>> +
>>> + struct media_pad pads[CSI2DC_PADS_NUM];
>>> +
>>> + bool clk_gated;
>>> + u32 inter_line_delay;
>>> + u32 vc;
>>> +
>>> + struct v4l2_async_subdev *asd;
>>> + struct v4l2_async_notifier notifier;
>>> +
>>> + struct v4l2_subdev *input_sd;
>>> + bool completed;
>>> +};
>>> +
>>> +static void csi2dc_vp_update(struct csi2dc_device *csi2dc)
>>> +{
>>> + u32 vp;
>>> +
>>> + vp = CSI2DC_VPCFG_DT(csi2dc->cur_fmt->dt) & CSI2DC_VPCFG_DT_MASK;
>>> + vp |= CSI2DC_VPCFG_VC(csi2dc->vc) & CSI2DC_VPCFG_VC_MASK;
>>> + vp &= ~CSI2DC_VPCFG_DE;
>>> + vp |= CSI2DC_VPCFG_DM(CSI2DC_VPCFG_DM_DECODER8TO12);
>>> + vp &= ~CSI2DC_VPCFG_DP2;
>>> + vp &= ~CSI2DC_VPCFG_RMS;
>>> + vp |= CSI2DC_VPCFG_PA;
>>> +
>>> + csi2dc_writel(csi2dc, CSI2DC_VPCFG, vp);
>>> + csi2dc_writel(csi2dc, CSI2DC_VPE, CSI2DC_VPE_ENABLE);
>>> + csi2dc_writel(csi2dc, CSI2DC_PU, CSI2DC_PU_VP);
>>> +}
>>> +
>>> +static inline struct csi2dc_device *csi2dc_sd_to_csi2dc_device
>>> + (struct v4l2_subdev *csi2dc_sd)
>>
>> I'd suggest wrapping after the asterisk.
>>
>>> +{
>>> + return container_of(csi2dc_sd, struct csi2dc_device, csi2dc_sd);
>>> +}
>>> +
>>> +static int csi2dc_enum_mbus_code(struct v4l2_subdev *csi2dc_sd,
>>> + struct v4l2_subdev_pad_config *cfg,
>>> + struct v4l2_subdev_mbus_code_enum *code)
>>> +{
>>> + struct csi2dc_device *csi2dc = csi2dc_sd_to_csi2dc_device(csi2dc_sd);
>>> +
>>> + if (code->index >= csi2dc->num_fmts)
>>> + return -EINVAL;
>>> +
>>> + code->code = csi2dc->formats[code->index]->mbus_code;
>>> + return 0;
>>> +}
>>> +
>>> +static int csi2dc_try_fmt(struct v4l2_subdev *csi2dc_sd,
>>> + struct v4l2_subdev_pad_config *cfg,
>>> + struct v4l2_subdev_format *req_fmt)
>>> +{
>>> + struct csi2dc_device *csi2dc = csi2dc_sd_to_csi2dc_device(csi2dc_sd);
>>> + struct csi2dc_format *fmt;
>>> +
>>> + if (!csi2dc->completed) {
>>> + dev_dbg((csi2dc)->dev, "subdev not registered yet\n");
>>
>> Uh... but can you end up here?
>
> Yes, if the subdevice has not yet registered.
> The CSI2DC registers as a subdevice for the next element in pipeline
> regardless of it's own subdevice.
> I encountered issues when trying to register the csi2dc at a later point
> than probe time (at the moment of it's own completion when the subdev is
> ready).
> Do you think I need to change , and have csi2dc registers itself for the
> next element at a later point ?
>
>>
>>> + return 0;
>>> + }
>>> +
>>> + for (fmt = csi2dc->formats[0]; fmt; fmt++)
>>> + if (req_fmt->format.code == fmt->mbus_code)
>>> + csi2dc->try_fmt = fmt;
>>> +
>>> + /* in case we could not find the desired format, default to something */
>>> + if (!csi2dc->try_fmt ||
>>> + req_fmt->format.code != csi2dc->try_fmt->mbus_code) {
>>> + csi2dc->try_fmt = csi2dc->formats[0];
>>> + req_fmt->format.code = csi2dc->formats[0]->mbus_code;
>>> + }
>>> +
>>> + return v4l2_subdev_call(csi2dc->input_sd, pad, set_fmt, cfg, req_fmt);
>>
>> For MC-enabled drivers (i.e. also those exposing sub-device nodes) the
>> formats are set (and also enumerated) by the user and validated by the
>> driver. See e.g. ipu3-cio2 driver for an example. It also includes DMA.
>
> To fully understand, I do not need to make a subdev call ? Just validate
> or invalidate the try format ?
>
>>
>>> +}
>>> +
>>> +static int csi2dc_set_fmt(struct v4l2_subdev *csi2dc_sd,
>>> + struct v4l2_subdev_pad_config *cfg,
>>> + struct v4l2_subdev_format *req_fmt)
>>> +{
>>> + struct csi2dc_device *csi2dc = csi2dc_sd_to_csi2dc_device(csi2dc_sd);
>>> + int ret;
>>> +
>>> + if (!csi2dc->completed) {
>>> + dev_dbg((csi2dc)->dev, "subdev not registered yet\n");
>>> + return 0;
>>> + }
>>> +
>>> + csi2dc_try_fmt(csi2dc_sd, cfg, req_fmt);
>>> +
>>> + if (csi2dc->try_fmt->mbus_code != req_fmt->format.code) {
>>> + dev_dbg(csi2dc->dev, "CSI2DC unsupported format 0x%x\n",
>>> + req_fmt->format.code);
>>> + return -EINVAL;
>>> + }
>>> +
>>> + ret = v4l2_subdev_call(csi2dc->input_sd, pad, set_fmt, cfg, req_fmt);
>>> + if (ret) {
>>> + dev_err(csi2dc->dev, "input subdev failed %d\n", ret);
>>> + return ret;
>>> + }
>>> +
>>> + csi2dc->cur_fmt = csi2dc->try_fmt;
>>> + /* update video pipe */
>>> + csi2dc_vp_update(csi2dc);
>>> +
>>> + dev_dbg(csi2dc->dev, "CSI2DC new format: 0x%x\n", req_fmt->format.code);
>>> + return 0;
>>> +}
>>> +
>>> +static int csi2dc_formats_init(struct csi2dc_device *csi2dc)
>>> +{
>>> + int i, j;
>>> + struct csi2dc_format *fmt = &csi2dc_formats_list[0];
>>> +
>>> + csi2dc->num_fmts = 1;
>>> +
>>> + csi2dc->formats = devm_kcalloc(csi2dc->dev, csi2dc->num_fmts,
>>> + sizeof(*csi2dc->formats), GFP_KERNEL);
>>> +
>>> + for (i = 0, j = 0; i < ARRAY_SIZE(csi2dc_formats_list); i++, fmt++)
>>> + if (fmt->mbus_code == MEDIA_BUS_FMT_SRGGB10_1X10)
>>> + csi2dc->formats[j++] = fmt;
>>> + return 0;
>>> +}
>>> +
>>> +static int csi2dc_s_power(struct v4l2_subdev *csi2dc_sd, int on)
>>
>> Please use runtime PM instead.
>
> And in this case, s_power on/off will be unused?
> The runtime PM will power on the pipeline when capture is required or it
> will have it powered on more than that ?
> Currently in my experiments when stopping the streaming, s_power off is
> also called afterwards, and the CSI2DC can be reset, as the MIPI lanes
> must reach a stop state to reinitialize capture later.
>
>>
>>> +{
>>> + struct csi2dc_device *csi2dc = csi2dc_sd_to_csi2dc_device(csi2dc_sd);
>>> + int ret = 0;
>>> +
>>> + if (!csi2dc->completed) {
>>> + dev_dbg((csi2dc)->dev, "subdev not registered yet\n");
>>> + return 0;
>>> + }
>>> +
>>> + if (on)
>>> + ret = clk_prepare_enable(csi2dc->scck);
>>> + else
>>> + clk_disable_unprepare(csi2dc->scck);
>>> + if (ret)
>>> + dev_err(csi2dc->dev, "failed to enable scck: %d\n", ret);
>>> +
>>> + /* if powering up, deassert reset line */
>>> + if (on)
>>> + csi2dc_writel(csi2dc, CSI2DC_GCTLR, CSI2DC_GCTLR_SWRST);
>>> +
>>> + ret = v4l2_subdev_call(csi2dc->input_sd, core, s_power, on);
>>> +
>>> + /* if powering down, assert reset line */
>>> + if (!on)
>>> + csi2dc_writel(csi2dc, CSI2DC_GCTLR, !CSI2DC_GCTLR_SWRST);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static int csi2dc_s_stream(struct v4l2_subdev *csi2dc_sd, int enable)
>>> +{
>>> + struct csi2dc_device *csi2dc = csi2dc_sd_to_csi2dc_device(csi2dc_sd);
>>> +
>>> + if (!csi2dc->completed) {
>>> + dev_dbg((csi2dc)->dev, "subdev not registered yet\n");
>>> + return 0;
>>> + }
>>> +
>>> + return v4l2_subdev_call(csi2dc->input_sd, video, s_stream, enable);
>>> +}
>>> +
>>> +static int csi2dc_g_frame_interval(struct v4l2_subdev *csi2dc_sd,
>>> + struct v4l2_subdev_frame_interval *interval)
>>> +{
>>> + struct csi2dc_device *csi2dc = csi2dc_sd_to_csi2dc_device(csi2dc_sd);
>>> +
>>> + if (!csi2dc->completed) {
>>> + dev_dbg((csi2dc)->dev, "subdev not registered yet\n");
>>> + return 0;
>>> + }
>>> +
>>> + return v4l2_subdev_call(csi2dc->input_sd, video, g_frame_interval,
>>> + interval);
>>> +}
>>> +
>>> +static int csi2dc_s_frame_interval(struct v4l2_subdev *csi2dc_sd,
>>> + struct v4l2_subdev_frame_interval *interval)
>>> +{
>>> + struct csi2dc_device *csi2dc = csi2dc_sd_to_csi2dc_device(csi2dc_sd);
>>> +
>>> + if (!csi2dc->completed) {
>>> + dev_dbg((csi2dc)->dev, "subdev not registered yet\n");
>>> + return 0;
>>> + }
>>> +
>>> + return v4l2_subdev_call(csi2dc->input_sd, video, s_frame_interval,
>>> + interval);
>>> +}
>>> +
>>> +static int csi2dc_enum_frame_size(struct v4l2_subdev *csi2dc_sd,
>>> + struct v4l2_subdev_pad_config *cfg,
>>> + struct v4l2_subdev_frame_size_enum *fse)
>>> +{
>>> + struct csi2dc_device *csi2dc = csi2dc_sd_to_csi2dc_device(csi2dc_sd);
>>> +
>>> + if (!csi2dc->completed) {
>>> + dev_dbg((csi2dc)->dev, "subdev not registered yet\n");
>>> + return 0;
>>> + }
>>> +
>>> + return v4l2_subdev_call(csi2dc->input_sd, pad, enum_frame_size, cfg,
>>> + fse);
>>> +}
>>> +
>>> +static int csi2dc_enum_frame_interval(struct v4l2_subdev *csi2dc_sd,
>>> + struct v4l2_subdev_pad_config *cfg,
>>> + struct v4l2_subdev_frame_interval_enum *fie)
>>> +{
>>> + struct csi2dc_device *csi2dc = csi2dc_sd_to_csi2dc_device(csi2dc_sd);
>>> +
>>> + if (!csi2dc->completed) {
>>> + dev_dbg((csi2dc)->dev, "subdev not registered yet\n");
>>> + return 0;
>>> + }
>>> +
>>> + return v4l2_subdev_call(csi2dc->input_sd, pad, enum_frame_interval, cfg,
>>> + fie);
>>> +}
>>> +
>>> +static struct v4l2_subdev_core_ops csi2dc_core_ops = {
>>> + .s_power = csi2dc_s_power,
>>> +};
>>> +
>>> +static struct v4l2_subdev_pad_ops csi2dc_pad_ops = {
>>> + .enum_mbus_code = csi2dc_enum_mbus_code,
>>> + .set_fmt = csi2dc_set_fmt,
>>> + .enum_frame_size = csi2dc_enum_frame_size,
>>> + .enum_frame_interval = csi2dc_enum_frame_interval,
>>> +};
>>> +
>>> +static struct v4l2_subdev_video_ops csi2dc_video_ops = {
>>> + .s_stream = csi2dc_s_stream,
>>> + .g_frame_interval = csi2dc_g_frame_interval,
>>> + .s_frame_interval = csi2dc_s_frame_interval,
>>> +};
>>> +
>>> +static struct v4l2_subdev_ops csi2dc_subdev_ops = {
>>> + .core = &csi2dc_core_ops,
>>> + .pad = &csi2dc_pad_ops,
>>> + .video = &csi2dc_video_ops,
>>> +};
>>
>> const. Applies to all above.
>>
>>> +
>>> +static int csi2dc_async_bound(struct v4l2_async_notifier *notifier,
>>> + struct v4l2_subdev *subdev,
>>> + struct v4l2_async_subdev *asd)
>>> +{
>>> + struct csi2dc_device *csi2dc = container_of(notifier->v4l2_dev,
>>> + struct csi2dc_device, v4l2_dev);
>>> + csi2dc->input_sd = subdev;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int csi2dc_async_complete(struct v4l2_async_notifier *notifier)
>>> +{
>>> + struct csi2dc_device *csi2dc = container_of(notifier->v4l2_dev,
>>
>> It'd be cleaner to wrap after "=". Or align the lines below after "(".
>>
>>> + struct csi2dc_device, v4l2_dev);
>>> + int ret;
>>> +
>>> + ret = v4l2_device_register_subdev_nodes(&csi2dc->v4l2_dev);
>>> + if (ret < 0) {
>>> + v4l2_err(&csi2dc->v4l2_dev, "failed to register subdev nodes\n");
>>> + return ret;
>>> + }
>>> +
>>> + csi2dc_writel(csi2dc, CSI2DC_GCFG,
>>> + (CSI2DC_GCFG_HLC(csi2dc->inter_line_delay) &
>>> + CSI2DC_GCFG_HLC_MASK) |
>>> + (csi2dc->clk_gated ? 0 : CSI2DC_GCFG_MIPIFRN));
>>> +
>>> + csi2dc_writel(csi2dc, CSI2DC_VPCOL,
>>> + CSI2DC_VPCOL_COL(0xFFF) & CSI2DC_VPCOL_COL_MASK);
>>> + csi2dc_writel(csi2dc, CSI2DC_VPROW,
>>> + CSI2DC_VPROW_ROW(0xFFF) & CSI2DC_VPROW_ROW_MASK);
>>> +
>>> + csi2dc->completed = true;
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static const struct v4l2_async_notifier_operations csi2dc_async_ops = {
>>> + .bound = csi2dc_async_bound,
>>> + .complete = csi2dc_async_complete,
>>> +};
>>> +
>>> +static void csi2dc_cleanup_notifier(struct csi2dc_device *csi2dc)
>>> +{
>>> + v4l2_async_notifier_unregister(&csi2dc->notifier);
>>> + v4l2_async_notifier_cleanup(&csi2dc->notifier);
>>> +}
>>> +
>>> +static int csi2dc_prepare_notifier(struct csi2dc_device *csi2dc,
>>> + struct device_node *input_parent)
>>> +{
>>> + int ret;
>>> +
>>> + v4l2_async_notifier_init(&csi2dc->notifier);
>>> +
>>> + csi2dc->asd = kzalloc(sizeof(*csi2dc->asd), GFP_KERNEL);
>>> + if (!csi2dc->asd)
>>> + return -ENOMEM;
>>> +
>>> + csi2dc->asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
>>> + csi2dc->asd->match.fwnode = of_fwnode_handle(input_parent);
>>> +
>>> + ret = v4l2_async_notifier_add_subdev(&csi2dc->notifier, csi2dc->asd);
>>> + if (ret) {
>>> + dev_err(csi2dc->dev, "failed to add async notifier.\n");
>>> + v4l2_async_notifier_cleanup(&csi2dc->notifier);
>>> + goto csi2dc_prepare_notifier_err;
>>> + }
>>> +
>>> + csi2dc->notifier.ops = &csi2dc_async_ops;
>>> +
>>> + ret = v4l2_async_notifier_register(&csi2dc->v4l2_dev,
>>> + &csi2dc->notifier);
>>> +
>>> + if (ret) {
>>> + dev_err(csi2dc->dev, "fail to register async notifier.\n");
>>> + goto csi2dc_prepare_notifier_err;
>>> + }
>>> +
>>> +csi2dc_prepare_notifier_err:
>>> + of_node_put(input_parent);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static int csi2dc_of_parse(struct csi2dc_device *csi2dc,
>>> + struct device_node *of_node)
>>> +{
>>> + struct device_node *input_node, *sink_node, *input_parent;
>>> + struct v4l2_fwnode_endpoint input_endpoint, sink_endpoint;
>>> + int ret;
>>> +
>>> + memset(&input_endpoint, 0, sizeof(input_endpoint));
>>> + memset(&sink_endpoint, 0, sizeof(sink_endpoint));
>>
>> Could you assign a field to 0 in the declaration instead?
>>
>> You should also set the bus type as I believe the driver supports a single
>> one at both endpoints.
>
> I thought about that, but on the input pad, what bus type I can use ?
> Synopsys IDI is not available in kernel.
>
>>
>> You could also use the fwnode property API instead so you could avoid
>> of_fwnode_handle() --- up to you.
>>
>>> +
>>> + input_node = of_graph_get_next_endpoint(of_node, NULL);
>>> +
>>> + if (!input_node) {
>>> + dev_err(csi2dc->dev, "missing port node at %s, input node is mandatory.\n",
>>> + of_node->full_name);
>>> + return -EINVAL;
>>> + }
>>> +
>>> + ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(input_node),
>>> + &input_endpoint);
>>> +
>>> + if (ret) {
>>> + dev_err(csi2dc->dev, "endpoint not defined at %s\n",
>>> + of_node->full_name);
>>> + return ret;
>>> + }
>>> +
>>> + input_parent = of_graph_get_remote_port_parent(input_node);
>>> + if (!input_parent) {
>>> + dev_err(csi2dc->dev, "could not get input node's parent node.\n");
>>> + return -EINVAL;
>>> + }
>>> +
>>> + sink_node = of_graph_get_next_endpoint(of_node, input_node);
>>
>> You'll need to obtain the endpoints by port here (and above, too).
>
> I obtain them in the order in the device tree, one by one. You suggest
> to use a different API such that they are obtained by port number ?
>
>>
>>> +
>>> + if (sink_node)
>>> + ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(sink_node),
>>> + &sink_endpoint);
>>> +
>>> + if (!sink_node || ret) {
>>> + dev_info(csi2dc->dev, "missing sink node at %s, data pipe available only.\n",
>>> + of_node->full_name);
>>> + } else {
>>> + csi2dc->video_pipe = true;
>>> + csi2dc->vc = sink_endpoint.base.id;
>>> +
>>> + dev_dbg(csi2dc->dev, "block %s %d.%d->%d.%d video pipe VC %d\n",
>>> + of_node->full_name, input_endpoint.base.port,
>>> + input_endpoint.base.id, sink_endpoint.base.port,
>>> + sink_endpoint.base.id, csi2dc->vc);
>>> + }
>>> +
>>> + csi2dc->clk_gated = of_property_read_bool(of_node,
>>> + "microchip,clk-gated");
>>> +
>>> + dev_dbg(csi2dc->dev, "%s clock\n",
>>> + (csi2dc->clk_gated ? "Gated" : "Free running"));
>>
>> Extra parentheses.
>>
>>> +
>>> + ret = of_property_read_u32(of_node, "microchip,inter-line-delay",
>>> + &csi2dc->inter_line_delay);
>>> +
>>> + if (ret || csi2dc->inter_line_delay > 16) {
>>> + dev_dbg(csi2dc->dev, "assuming inter line delay = 16 clocks");
>>> + csi2dc->inter_line_delay = 16;
>>> + ret = 0;
>>> + }
>>> + /* hardware automatically adds 1 */
>>> + csi2dc->inter_line_delay--;
>>
>> What happens if 0 was read from DT?
>>
>>> +
>>> + /* prepare async notifier for subdevice completion */
>>> +
>>> + if (sink_node)
>>> + of_node_put(sink_node);
>>
>> of_node_put() is NULL-safe.
>>
>>> + of_node_put(input_node);
>>> +
>>> + return csi2dc_prepare_notifier(csi2dc, input_parent);
>>> +}
>>> +
>>> +static int csi2dc_probe(struct platform_device *pdev)
>>> +{
>>> + struct device *dev = &pdev->dev;
>>> + struct csi2dc_device *csi2dc;
>>> + struct resource *res = NULL;
>>> + int ret = 0;
>>> +
>>> + csi2dc = devm_kzalloc(dev, sizeof(*csi2dc), GFP_KERNEL);
>>> + if (!csi2dc)
>>> + return -ENOMEM;
>>> +
>>> + csi2dc->dev = dev;
>>> +
>>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>> + if (!res)
>>> + return -EINVAL;
>>> +
>>> + csi2dc->base = devm_ioremap_resource(dev, res);
>>> +
>>> + if (IS_ERR(csi2dc->base)) {
>>> + dev_err(dev, "base address not set\n");
>>> + return PTR_ERR(csi2dc->base);
>>> + }
>>> +
>>> + csi2dc->pclk = devm_clk_get(dev, "pclk");
>>> + if (IS_ERR(csi2dc->pclk)) {
>>> + ret = PTR_ERR(csi2dc->pclk);
>>> + dev_err(dev, "failed to get pclk: %d\n", ret);
>>> + return ret;
>>> + }
>>> +
>>> + ret = clk_prepare_enable(csi2dc->pclk);
>>> + if (ret) {
>>> + dev_err(dev, "failed to enable pclk: %d\n", ret);
>>> + return ret;
>>> + }
>>> +
>>> + csi2dc->scck = devm_clk_get(dev, "scck");
>>> + if (IS_ERR(csi2dc->scck)) {
>>> + ret = PTR_ERR(csi2dc->scck);
>>> + dev_err(dev, "failed to get scck: %d\n", ret);
>>> + goto csi2dc_clk_fail;
>>> + }
>>> +
>>> + ret = v4l2_device_register(dev, &csi2dc->v4l2_dev);
>>> + if (ret) {
>>> + dev_err(dev, "unable to register v4l2 device.\n");
>>> + goto csi2dc_clk_fail;
>>> + }
>>> +
>>> + v4l2_subdev_init(&csi2dc->csi2dc_sd, &csi2dc_subdev_ops);
>>> +
>>> + csi2dc->csi2dc_sd.owner = THIS_MODULE;
>>> +
>>
>> No need for a newline.
>>
>>> + csi2dc->csi2dc_sd.dev = dev;
>>> + snprintf(csi2dc->csi2dc_sd.name, sizeof(csi2dc->csi2dc_sd.name),
>>> + "%s.%d", "CSI2DC", 0);
>>
>> The number is always zero.
>>
>>> +
>>> + csi2dc->csi2dc_sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
>>> + csi2dc->csi2dc_sd.entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
>>> + csi2dc->pads[CSI2DC_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
>>> + csi2dc->pads[CSI2DC_PAD_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
>>> +
>>> + ret = media_entity_pads_init(&csi2dc->csi2dc_sd.entity, CSI2DC_PADS_NUM,
>>> + csi2dc->pads);
>>> + if (ret < 0) {
>>> + dev_err(dev, "media entity init failed\n");
>>> + goto csi2dc_probe_entity_err;
>>> + }
>>> +
>>> + v4l2_set_subdevdata(&csi2dc->csi2dc_sd, pdev);
>>> +
>>> + platform_set_drvdata(pdev, &csi2dc->csi2dc_sd);
>>> +
>>> + ret = csi2dc_of_parse(csi2dc, dev->of_node);
>>> + if (ret)
>>> + goto csi2dc_probe_entity_err;
>>> +
>>> + ret = csi2dc_formats_init(csi2dc);
>>> + if (ret)
>>> + goto csi2dc_probe_error;
>>> +
>>> + ret = v4l2_async_register_subdev(&csi2dc->csi2dc_sd);
>>> + if (ret) { // ret = -EPROBE_DEFER;
>>
>> Oops.
>>
>>> + goto csi2dc_probe_error;
>>> + }
>>> +
>>> + pm_runtime_set_active(dev);
>>> + pm_runtime_enable(dev);
>>> + pm_request_idle(dev);
>>> +
>>> + pr_info("Microchip CSI2DC version %x\n",
>>> + csi2dc_readl(csi2dc, CSI2DC_VERSION));
>>
>> What happens if the device was powered down already?
>
> I am moving the info line before pm_request_idle, if this was what you
> had in mind.
>
> I am sending a v3 of the patch, with some of the comments addressed.
> Some others I do not fully understand yet how to change. Hopefully your
> replies will help me find the way.
>
> Thanks again,
> Eugen
>>
>>> +
>>> + return 0;
>>> +
>>> +csi2dc_probe_error:
>>> + v4l2_async_unregister_subdev(&csi2dc->csi2dc_sd);
>>> + csi2dc_cleanup_notifier(csi2dc);
>>> +
>>> +csi2dc_probe_entity_err:
>>> + media_entity_cleanup(&csi2dc->csi2dc_sd.entity);
>>> + v4l2_device_unregister(&csi2dc->v4l2_dev);
>>> +csi2dc_clk_fail:
>>> + clk_disable_unprepare(csi2dc->pclk);
>>> + return ret;
>>> +}
>>> +
>>> +static int csi2dc_remove(struct platform_device *pdev)
>>> +{
>>> + struct v4l2_subdev *csi2dc_sd = platform_get_drvdata(pdev);
>>> + struct csi2dc_device *csi2dc = csi2dc_sd_to_csi2dc_device(csi2dc_sd);
>>> +
>>> + pm_runtime_disable(&pdev->dev);
>>> + csi2dc_cleanup_notifier(csi2dc);
>>> + media_entity_cleanup(&csi2dc->csi2dc_sd.entity);
>>> + v4l2_device_unregister(&csi2dc->v4l2_dev);
>>> + clk_disable_unprepare(csi2dc->pclk);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int __maybe_unused csi2dc_runtime_suspend(struct device *dev)
>>> +{
>>> + return 0;
>>> +}
>>> +
>>> +static int __maybe_unused csi2dc_runtime_resume(struct device *dev)
>>> +{
>>> + return 0;
>>> +}
>>> +
>>> +static const struct dev_pm_ops csi2dc_dev_pm_ops = {
>>> + SET_RUNTIME_PM_OPS(csi2dc_runtime_suspend, csi2dc_runtime_resume, NULL)
>>> +};
>>> +
>>> +static const struct of_device_id csi2dc_of_match[] = {
>>> + { .compatible = "microchip,sama7g5-csi2dc" },
>>> + { }
>>> +};
>>> +
>>> +MODULE_DEVICE_TABLE(of, csi2dc_of_match);
>>> +
>>> +static struct platform_driver csi2dc_driver = {
>>> + .probe = csi2dc_probe,
>>> + .remove = csi2dc_remove,
>>> + .driver = {
>>> + .name = "microchip-csi2dc",
>>> + .pm = &csi2dc_dev_pm_ops,
>>> + .of_match_table = of_match_ptr(csi2dc_of_match),
>>> + },
>>> +};
>>> +
>>> +module_platform_driver(csi2dc_driver);
>>> +
>>> +MODULE_AUTHOR("Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>");
>>> +MODULE_DESCRIPTION("Microchip CSI2 Demux Controller driver");
>>> +MODULE_LICENSE("GPL v2");
>>> +MODULE_SUPPORTED_DEVICE("video");
>>
>> --
>> Kind regards,
>>
>> Sakari Ailus
>>
>