Re: [PATCH v4 2/4] [media] platform: Add Synopsys Designware HDMI RX Controller Driver

[Sylwester Nawrocki <snawrocki@kernel.org>]

On 06/20/2017 07:26 PM, Jose Abreu wrote:
> This is an initial submission for the Synopsys Designware HDMI RX
> Controller Driver. This driver interacts with a phy driver so that
> a communication between them is created and a video pipeline is
> configured.

> Signed-off-by: Jose Abreu <joabreu@synopsys.com>
> Cc: Carlos Palminha <palminha@synopsys.com>
> Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
> Cc: Hans Verkuil <hans.verkuil@cisco.com>
> Cc: Sylwester Nawrocki <snawrocki@kernel.org>
> 
> Changes from v3:
> 	- Use v4l2 async API (Sylwester)
> 	- Do not block waiting for phy
> 	- Do not use busy waiting delays (Sylwester)
> 	- Simplify dw_hdmi_power_on (Sylwester)
> 	- Use clock API (Sylwester)
> 	- Use compatible string (Sylwester)
> 	- Minor fixes (Sylwester)
> Changes from v2:
> 	- Address review comments from Hans regarding CEC
> 	- Use CEC notifier
> 	- Enable SCDC
> Changes from v1:
> 	- Add support for CEC
> 	- Correct typo errors
> 	- Correctly detect interlaced video modes
> 	- Correct VIC parsing
> Changes from RFC:
> 	- Add support for HDCP 1.4
> 	- Fixup HDMI_VIC not being parsed (Hans)
> 	- Send source change signal when powering off (Hans)
> 	- Add a "wait stable delay"
> 	- Detect interlaced video modes (Hans)
> 	- Restrain g/s_register from reading/writing to HDCP regs (Hans)
> ---
>   drivers/media/platform/dwc/Kconfig      |   15 +
>   drivers/media/platform/dwc/Makefile     |    1 +
>   drivers/media/platform/dwc/dw-hdmi-rx.c | 1862 +++++++++++++++++++++++++++++++
>   drivers/media/platform/dwc/dw-hdmi-rx.h |  441 ++++++++
>   include/media/dwc/dw-hdmi-rx-pdata.h    |   97 ++
>   5 files changed, 2416 insertions(+)
>   create mode 100644 drivers/media/platform/dwc/dw-hdmi-rx.c
>   create mode 100644 drivers/media/platform/dwc/dw-hdmi-rx.h
>   create mode 100644 include/media/dwc/dw-hdmi-rx-pdata.h
> 

> diff --git a/drivers/media/platform/dwc/dw-hdmi-rx.c b/drivers/media/platform/dwc/dw-hdmi-rx.c
> new file mode 100644
> index 0000000..22ee51d
> --- /dev/null
> +++ b/drivers/media/platform/dwc/dw-hdmi-rx.c

> +static const struct of_device_id dw_hdmi_supported_phys[] = {
> +	{ .compatible = "snps,dw-hdmi-phy-e405", .data = DW_PHY_E405_DRVNAME, },
> +	{ },
> +};
> +
> +static struct device_node *dw_hdmi_get_phy_of_node(struct dw_hdmi_dev *dw_dev,
> +		const struct of_device_id **found_id)
> +{
> +	struct device_node *child = NULL;
> +	const struct of_device_id *id;
> +
> +	for_each_child_of_node(dw_dev->of_node, child) {
> +		id = of_match_node(dw_hdmi_supported_phys, child);
> +		if (id)
> +			break;
> +	}
> +
> +	if (found_id)
> +		*found_id = id;
> +
> +	return child;
> +}
> +
> +static int dw_hdmi_phy_init(struct dw_hdmi_dev *dw_dev)
> +{
> +	struct dw_phy_pdata *phy = &dw_dev->phy_config;
> +	const struct of_device_id *of_id;
> +	struct of_dev_auxdata lookup;

	struct of_dev_auxdata lookup = { };

You could initialize to 0 here and...

> +	struct device_node *child;
> +	const char *drvname;
> +	int ret;
> +
> +	child = dw_hdmi_get_phy_of_node(dw_dev, &of_id);
> +	if (!child || !of_id || !of_id->data) {
> +		dev_err(dw_dev->dev, "no supported phy found in DT\n");
> +		return -EINVAL;
> +	}
> +
> +	drvname = of_id->data;
> +	phy->funcs = &dw_hdmi_phy_funcs;
> +	phy->funcs_arg = dw_dev;
> +
> +	lookup.compatible = (char *)of_id->compatible;
> +	lookup.phys_addr = 0x0;
> +	lookup.name = NULL;

...drop these two assignments.

> +	lookup.platform_data = phy;
> +
> +	request_module(drvname);

I'd say this request_module() is not needed when you use the v4l2-async 
subnotifiers and the modules are properly installed in the file system.
I might be missing something though.

> +	ret = of_platform_populate(dw_dev->of_node, NULL, &lookup, dw_dev->dev);
> +	if (ret) {
> +		dev_err(dw_dev->dev, "failed to populate phy driver\n");
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static void dw_hdmi_phy_exit(struct dw_hdmi_dev *dw_dev)
> +{
> +	of_platform_depopulate(dw_dev->dev);
> +}

> +static int dw_hdmi_registered(struct v4l2_subdev *sd)
> +{
> +	struct dw_hdmi_dev *dw_dev = to_dw_dev(sd);
> +	int ret;
> +
> +	ret = cec_register_adapter(dw_dev->cec_adap, dw_dev->dev);
> +	if (ret) {
> +		dev_err(dw_dev->dev, "failed to register CEC adapter\n");
> +		cec_delete_adapter(dw_dev->cec_adap);
> +		return ret;
> +	}
> +
> +	cec_register_cec_notifier(dw_dev->cec_adap, dw_dev->cec_notifier);
> +	dw_dev->registered = true;
> +	return ret;
> +}
> +
> +static void dw_hdmi_unregistered(struct v4l2_subdev *sd)
> +{
> +	struct dw_hdmi_dev *dw_dev = to_dw_dev(sd);
> +
> +	cec_unregister_adapter(dw_dev->cec_adap);
> +	cec_notifier_put(dw_dev->cec_notifier);
> +}
> +

> +static const struct v4l2_subdev_internal_ops dw_hdmi_internal_ops = {
> +	.registered = dw_hdmi_registered,
> +	.unregistered = dw_hdmi_unregistered,
> +};
> +
> +static int dw_hdmi_v4l2_notify_bound(struct v4l2_async_notifier *notifier,
> +		struct v4l2_subdev *subdev, struct v4l2_async_subdev *asd)
> +{
> +	struct dw_hdmi_dev *dw_dev = notifier_to_dw_dev(notifier);
> +
> +	if (dw_dev->phy_async_sd.match.fwnode.fwnode ==
> +			of_fwnode_handle(subdev->dev->of_node)) {
> +		dev_dbg(dw_dev->dev, "found new subdev '%s'\n", subdev->name);
> +		dw_dev->phy_sd = subdev;
> +		return 0;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static void dw_hdmi_v4l2_notify_unbind(struct v4l2_async_notifier *notifier,
> +		struct v4l2_subdev *subdev, struct v4l2_async_subdev *asd)
> +{
> +	struct dw_hdmi_dev *dw_dev = notifier_to_dw_dev(notifier);
> +
> +	if (dw_dev->phy_sd == subdev) {
> +		dev_dbg(dw_dev->dev, "unbinding '%s'\n", subdev->name);
> +		dw_dev->phy_sd = NULL;
> +	}
> +}
> +
> +static int dw_hdmi_v4l2_notify_complete(struct v4l2_async_notifier *notifier)
> +{
> +	struct dw_hdmi_dev *dw_dev = notifier_to_dw_dev(notifier);
> +	int ret;
> +
> +	ret = v4l2_device_register_subdev_nodes(&dw_dev->v4l2_dev);

There shouldn't be multiple struct v4l2_device instances, instead we should 
have only one created by the main driver. AFAIU, in your case it would be 
driver associated with the dw-hdmi-soc DT node.  And normally such a top level 
driver creates subdev device nodes when its all required sub-devices are 
available.

I think this patch could be useful for you:
https://patchwork.linuxtv.org/patch/41834

With that the dw-hdmi-soc driver would have it's v4l2-async notifier's
notify_complete() callback called only when both the hdmi-rx and the
hdmi-phy subdevs are registered.

> +	if (ret) {
> +		dev_err(dw_dev->dev, "failed to register subdev nodes\n");
> +		return ret;
> +	}
> +
> +	return 0;
> +}

> +static int dw_hdmi_parse_dt(struct dw_hdmi_dev *dw_dev)
> +{

> +	ret = clk_prepare_enable(dw_dev->clk);
> +	if (ret) {
> +		dev_err(dw_dev->dev, "failed to enable cfg-clk\n");
> +		return ret;
> +	}
> +
> +	dw_dev->cfg_clk = clk_get_rate(dw_dev->clk) / 1000000;

1000000U ?

> +	if (!dw_dev->cfg_clk) {
> +		dev_err(dw_dev->dev, "invalid cfg-clk frequency\n");
> +		ret = -EINVAL;
> +		goto err_clk;
> +	}
> +

> +	return 0;
> +
> +err_clk:
> +	clk_disable_unprepare(dw_dev->clk);
> +	return ret;
> +}
> +
> +static int dw_hdmi_rx_probe(struct platform_device *pdev)
> +{

> +	/* V4L2 initialization */
> +	sd = &dw_dev->sd;
> +	v4l2_subdev_init(sd, &dw_hdmi_sd_ops);
> +	strlcpy(sd->name, dev_name(dev), sizeof(sd->name));
> +	sd->dev = dev;
> +	sd->internal_ops = &dw_hdmi_internal_ops;
> +	sd->flags |= V4L2_SUBDEV_FL_HAS_EVENTS;

Don't you also need V4L2_SUBDEV_FL_HAS_DEVNODE flag set?

> +	/* Notifier for subdev binding */
> +	ret = dw_hdmi_v4l2_init_notifier(dw_dev);
> +	if (ret) {
> +		dev_err(dev, "failed to init v4l2 notifier\n");
> +		goto err_v4l2_dev;
> +	}
> +
> +	/* Phy loading */

s/Phy/PHY/ ?

> +	ret = dw_hdmi_phy_init(dw_dev);
> +	if (ret)
> +		goto err_v4l2_notifier;
> +

> +	ret = v4l2_async_register_subdev(sd);
> +	if (ret) {
> +		dev_err(dev, "failed to register subdev\n");
> +		goto err_cec;
> +	}
> +
> +	/* Fill initial format settings */
> +	dw_dev->timings = timings_def;
> +	dw_dev->mbus_code = MEDIA_BUS_FMT_BGR888_1X24;
> +
> +	/* All done */

This comment seems unneeded.

> +	dev_set_drvdata(dev, sd);
> +	dw_dev->state = HDMI_STATE_POWER_OFF;
> +	dw_hdmi_detect_tx_5v(dw_dev);

> +	dev_info(dev, "driver probed\n");

dev_dbg()

> +	return 0;
> +
> +err_cec:
> +	cec_delete_adapter(dw_dev->cec_adap);
> +err_phy:
> +	dw_hdmi_phy_exit(dw_dev);
> +err_v4l2_notifier:
> +	v4l2_async_notifier_unregister(&dw_dev->v4l2_notifier);
> +err_v4l2_dev:
> +	v4l2_device_unregister(&dw_dev->v4l2_dev);
> +err_wq:
> +	destroy_workqueue(dw_dev->wq);
> +	return ret;
> +}
> +
> +static int dw_hdmi_rx_remove(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct v4l2_subdev *sd = dev_get_drvdata(dev);
> +	struct dw_hdmi_dev *dw_dev = to_dw_dev(sd);
> +
> +	dev_dbg(dev, "%s\n", __func__);
> +
> +	dw_hdmi_disable_ints(dw_dev);
> +	dw_hdmi_disable_hpd(dw_dev);
> +	dw_hdmi_disable_scdc(dw_dev);
> +	dw_hdmi_power_off(dw_dev);
> +	dw_hdmi_phy_s_power(dw_dev, false);
> +	flush_workqueue(dw_dev->wq);
> +	destroy_workqueue(dw_dev->wq);
> +	v4l2_device_unregister(&dw_dev->v4l2_dev);
> +	dw_hdmi_phy_exit(dw_dev);
> +	v4l2_async_unregister_subdev(sd);
> +	clk_disable_unprepare(dw_dev->clk);

> +	dev_info(dev, "driver removed\n");

dev_dbg()

> +	return 0;
> +}
> +
> +static const struct of_device_id dw_hdmi_rx_id[] = {
> +	{ .compatible = "snps,dw-hdmi-rx" },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(of, dw_hdmi_rx_id);

--
Regards,
Sylwester