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[v2,00/12] Add functionality to ipu3-cio2 driver allowing software_node connections to sensors on platforms designed for Windows

Message ID 20201217234337.1983732-1-djrscally@gmail.com
Headers show
Series Add functionality to ipu3-cio2 driver allowing software_node connections to sensors on platforms designed for Windows | expand

Message

Daniel Scally Dec. 17, 2020, 11:43 p.m. UTC
Hello all

Previous version:
https://lore.kernel.org/linux-media/20201130133129.1024662-1-djrscally@gmail.com/T/#m91934e12e3d033da2e768e952ea3b4a125ee3e67
The RFC version before that:
https://lore.kernel.org/linux-media/20201019225903.14276-1-djrscally@gmail.com/

This series is to start adding support for webcams on laptops with ACPI tables
designed for use with CIO2 on Windows. This problem has two main parts; the
first part, which is handled in this series, is extending the ipu3-cio2
driver to allow for patching the firmware via software_nodes if endpoints
aren't defined by ACPI. The second is adding a new driver to handle power,
clocks and GPIO pins defined in DSDT tables in an awkward way. I decided to
split that second part out from this series, and instead give it its own
series (a v2 of which should land "soon"). The reasons for that are:

1. It's a logically separate change anyway
2. The recipients list was getting really long and
3. That probably meant that handling merge for all of this in one go was
   going to be impractically awkward.

Given how few comments the remaining patches of this series received in the
last posting, I'm hopeful that most or all of it could get picked up for 5.12.
We touch a few different areas:

lib (with an ack already)
  lib/test_printf.c: Use helper function to unwind array of
    software_nodes

drivers/base
  software_node: Fix refcounts in software_node_get_next_child()
  property: Return true in fwnode_device_is_available for NULL ops
  property: Call fwnode_graph_get_endpoint_by_id() for fwnode->secondary
  software_node: Enforce parent before child ordering of nodes arrays
  software_node: unregister software_nodes in reverse order

drivers/acpi
  acpi: Add acpi_dev_get_next_match_dev() and helper macro

drivers/media
  media: v4l2-core: v4l2-async: Check sd->fwnode->secondary in
    match_fwnode()
  ipu3-cio2: Add T: entry to MAINTAINERS
  ipu3-cio2: Rename ipu3-cio2.c
  ipu3-cio2: Add cio2-bridge to ipu3-cio2 driver

Given that, it feels sensible to me to try and merge them all through a single
tree; I was hoping the other maintainers would be amenable to having everything
merged through the media tree. Mauro; if that plan is ok (and of course assuming
that the rest of the patches are acked by their respective maintainers too),
could we get a dedicated feature branch just in case the following series ends
up being ready in time too? 

Series-level changelog:
	- Squashed the patches enforcing ordering in register/unregister_nodes()

More details of changes on each patch.

Comments as always very welcome - and thanks to everyone for all your help on
this so far, hope I've addressed everything from last time.

Dan

Daniel Scally (11):
  software_node: Fix refcounts in software_node_get_next_child()
  property: Return true in fwnode_device_is_available for NULL ops
  property: Call fwnode_graph_get_endpoint_by_id() for fwnode->secondary
  software_node: Enforce parent before child ordering of nodes arrays
  software_node: unregister software_nodes in reverse order
  lib/test_printf.c: Use helper function to unwind array of
    software_nodes
  ipu3-cio2: Add T: entry to MAINTAINERS
  ipu3-cio2: Rename ipu3-cio2.c
  media: v4l2-core: v4l2-async: Check sd->fwnode->secondary in
    match_fwnode()
  acpi: Add acpi_dev_get_next_match_dev() and helper macro
  ipu3-cio2: Add cio2-bridge to ipu3-cio2 driver

Heikki Krogerus (1):
  software_node: Add support for fwnode_graph*() family of functions

 MAINTAINERS                                   |   2 +
 drivers/acpi/utils.c                          |  30 +-
 drivers/base/property.c                       |  15 +-
 drivers/base/swnode.c                         | 173 +++++++++--
 drivers/media/pci/intel/ipu3/Kconfig          |  18 ++
 drivers/media/pci/intel/ipu3/Makefile         |   3 +
 drivers/media/pci/intel/ipu3/cio2-bridge.c    | 274 ++++++++++++++++++
 drivers/media/pci/intel/ipu3/cio2-bridge.h    | 122 ++++++++
 .../ipu3/{ipu3-cio2.c => ipu3-cio2-main.c}    |  34 +++
 drivers/media/pci/intel/ipu3/ipu3-cio2.h      |   6 +
 drivers/media/v4l2-core/v4l2-async.c          |   8 +
 include/acpi/acpi_bus.h                       |   7 +
 lib/test_printf.c                             |   4 +-
 13 files changed, 669 insertions(+), 27 deletions(-)
 create mode 100644 drivers/media/pci/intel/ipu3/cio2-bridge.c
 create mode 100644 drivers/media/pci/intel/ipu3/cio2-bridge.h
 rename drivers/media/pci/intel/ipu3/{ipu3-cio2.c => ipu3-cio2-main.c} (98%)

Comments

Laurent Pinchart Dec. 18, 2020, 4:02 p.m. UTC | #1
Hi Daniel,

Thank you for the patch.

On Thu, Dec 17, 2020 at 11:43:29PM +0000, Daniel Scally wrote:
> Registering software_nodes with the .parent member set to point to a

> currently unregistered software_node has the potential for problems,

> so enforce parent -> child ordering in arrays passed in to

> software_node_register_nodes().

> 

> Software nodes that are children of another software node should be

> unregistered before their parent. To allow easy unregistering of an array

> of software_nodes ordered parent to child, reverse the order in which

> software_node_unregister_nodes() unregisters software_nodes.

> 

> Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

> Signed-off-by: Daniel Scally <djrscally@gmail.com>

> ---

> Changes in v2:

> 

> 	- Squashed the patches that originally touched these separately

> 	- Updated documentation

> 

>  drivers/base/swnode.c | 43 ++++++++++++++++++++++++++++++-------------

>  1 file changed, 30 insertions(+), 13 deletions(-)

> 

> diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c

> index 615a0c93e116..cfd1faea48a7 100644

> --- a/drivers/base/swnode.c

> +++ b/drivers/base/swnode.c

> @@ -692,7 +692,10 @@ swnode_register(const struct software_node *node, struct swnode *parent,

>   * software_node_register_nodes - Register an array of software nodes

>   * @nodes: Zero terminated array of software nodes to be registered

>   *

> - * Register multiple software nodes at once.

> + * Register multiple software nodes at once. If any node in the array

> + * has it's .parent pointer set, then it's parent **must** have been

> + * registered before it is; either outside of this function or by

> + * ordering the array such that parent comes before child.

>   */

>  int software_node_register_nodes(const struct software_node *nodes)

>  {

> @@ -700,33 +703,47 @@ int software_node_register_nodes(const struct software_node *nodes)

>  	int i;

>  

>  	for (i = 0; nodes[i].name; i++) {

> -		ret = software_node_register(&nodes[i]);

> -		if (ret) {

> -			software_node_unregister_nodes(nodes);

> -			return ret;

> +		const struct software_node *parent = nodes[i].parent;

> +

> +		if (parent && !software_node_to_swnode(parent)) {

> +			ret = -EINVAL;

> +			goto err_unregister_nodes;

>  		}

> +

> +		ret = software_node_register(&nodes[i]);

> +		if (ret)

> +			goto err_unregister_nodes;

>  	}

>  

>  	return 0;

> +

> +err_unregister_nodes:

> +	software_node_unregister_nodes(nodes);

> +	return ret;

>  }

>  EXPORT_SYMBOL_GPL(software_node_register_nodes);

>  

>  /**

>   * software_node_unregister_nodes - Unregister an array of software nodes

> - * @nodes: Zero terminated array of software nodes to be unregistered

> + * @nodes: Zero terminated array of software nodes to be unregistered.


Not sure if this is needed.

>   *

> - * Unregister multiple software nodes at once.

> + * Unregister multiple software nodes at once. If parent pointers are set up

> + * in any of the software nodes then the array MUST be ordered such that


I'd either replace **must** above with MUST, or use **must** here. I'm
not sure if kerneldoc handles emphasis with **must**, if it does that
seems a bit nicer to me, but it's really up to you.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>


> + * parents come before their children.

>   *

> - * NOTE: Be careful using this call if the nodes had parent pointers set up in

> - * them before registering.  If so, it is wiser to remove the nodes

> - * individually, in the correct order (child before parent) instead of relying

> - * on the sequential order of the list of nodes in the array.

> + * NOTE: If you are uncertain whether the array is ordered such that

> + * parents will be unregistered before their children, it is wiser to

> + * remove the nodes individually, in the correct order (child before

> + * parent).

>   */

>  void software_node_unregister_nodes(const struct software_node *nodes)

>  {

> -	int i;

> +	unsigned int i = 0;

> +

> +	while (nodes[i].name)

> +		i++;

>  

> -	for (i = 0; nodes[i].name; i++)

> +	while (i--)

>  		software_node_unregister(&nodes[i]);

>  }

>  EXPORT_SYMBOL_GPL(software_node_unregister_nodes);


-- 
Regards,

Laurent Pinchart
Laurent Pinchart Dec. 18, 2020, 4:53 p.m. UTC | #2
Hi Daniel,

Thank you for the patch.

On Thu, Dec 17, 2020 at 11:43:37PM +0000, Daniel Scally wrote:
> Currently on platforms designed for Windows, connections between CIO2 and
> sensors are not properly defined in DSDT. This patch extends the ipu3-cio2
> driver to compensate by building software_node connections, parsing the
> connection properties from the sensor's SSDB buffer.
> 
> Suggested-by: Jordan Hand <jorhand@linux.microsoft.com>
> Signed-off-by: Daniel Scally <djrscally@gmail.com>
> ---
> Changes in v2:
> 
> 	- Dropped some headers
> 	- Added support for specifying link-frequencies in the array of
> 	cio2_supported_sensors and added that property to the endpoint.
> 	- Replaced strcpy with strscpy (Laurent, I liked your change better
> 	stylistically but ofc the string literals are lost when the module
> 	is reloaded)
> 	- Named the ports/endpoints "port@%u"
> 	- Added an overflow check to cio2_bridge_connect_sensors()
> 	- A bunch of cosmetic changes
> 
> For the cio2_supported_sensors array, specify link frequencies in this
> manner: 
> 
> 	CIO2_SENSOR_CONFIG("OVTI5648", 2, 16800000, 2100000)
> 
>  MAINTAINERS                                   |   1 +
>  drivers/media/pci/intel/ipu3/Kconfig          |  18 ++
>  drivers/media/pci/intel/ipu3/Makefile         |   1 +
>  drivers/media/pci/intel/ipu3/cio2-bridge.c    | 274 ++++++++++++++++++
>  drivers/media/pci/intel/ipu3/cio2-bridge.h    | 122 ++++++++
>  drivers/media/pci/intel/ipu3/ipu3-cio2-main.c |  34 +++
>  drivers/media/pci/intel/ipu3/ipu3-cio2.h      |   6 +
>  7 files changed, 456 insertions(+)
>  create mode 100644 drivers/media/pci/intel/ipu3/cio2-bridge.c
>  create mode 100644 drivers/media/pci/intel/ipu3/cio2-bridge.h
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 16b544624577..e7784b4bc8ea 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -8943,6 +8943,7 @@ INTEL IPU3 CSI-2 CIO2 DRIVER
>  M:	Yong Zhi <yong.zhi@intel.com>
>  M:	Sakari Ailus <sakari.ailus@linux.intel.com>
>  M:	Bingbu Cao <bingbu.cao@intel.com>
> +M:	Dan Scally <djrscally@gmail.com>
>  R:	Tianshu Qiu <tian.shu.qiu@intel.com>
>  L:	linux-media@vger.kernel.org
>  S:	Maintained
> diff --git a/drivers/media/pci/intel/ipu3/Kconfig b/drivers/media/pci/intel/ipu3/Kconfig
> index 82d7f17e6a02..dcf5c4b74673 100644
> --- a/drivers/media/pci/intel/ipu3/Kconfig
> +++ b/drivers/media/pci/intel/ipu3/Kconfig
> @@ -16,3 +16,21 @@ config VIDEO_IPU3_CIO2
>  	  Say Y or M here if you have a Skylake/Kaby Lake SoC with MIPI CSI-2
>  	  connected camera.
>  	  The module will be called ipu3-cio2.
> +
> +config CIO2_BRIDGE
> +	bool "IPU3 CIO2 Sensors Bridge"
> +	depends on VIDEO_IPU3_CIO2
> +	help
> +	  This extension provides an API for the ipu3-cio2 driver to create
> +	  connections to cameras that are hidden in SSDB buffer in ACPI. It
> +	  can be used to enable support for cameras in detachable / hybrid
> +	  devices that ship with Windows.
> +
> +	  Say Y here if your device is a detachable / hybrid laptop that comes
> +	  with Windows installed by the OEM, for example:
> +
> +		- Microsoft Surface models (except Surface Pro 3)
> +		- The Lenovo Miix line (for example the 510, 520, 710 and 720)
> +		- Dell 7285
> +
> +	  If in doubt, say N here.
> diff --git a/drivers/media/pci/intel/ipu3/Makefile b/drivers/media/pci/intel/ipu3/Makefile
> index 429d516452e4..933777e6ea8a 100644
> --- a/drivers/media/pci/intel/ipu3/Makefile
> +++ b/drivers/media/pci/intel/ipu3/Makefile
> @@ -2,3 +2,4 @@
>  obj-$(CONFIG_VIDEO_IPU3_CIO2) += ipu3-cio2.o
>  
>  ipu3-cio2-y += ipu3-cio2-main.o
> +ipu3-cio2-$(CONFIG_CIO2_BRIDGE) += cio2-bridge.o
> diff --git a/drivers/media/pci/intel/ipu3/cio2-bridge.c b/drivers/media/pci/intel/ipu3/cio2-bridge.c
> new file mode 100644
> index 000000000000..3f0e2d7eab20
> --- /dev/null
> +++ b/drivers/media/pci/intel/ipu3/cio2-bridge.c
> @@ -0,0 +1,274 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Author: Dan Scally <djrscally@gmail.com> */
> +
> +#include <linux/acpi.h>
> +#include <linux/device.h>
> +#include <linux/pci.h>
> +#include <linux/property.h>
> +
> +#include "cio2-bridge.h"
> +
> +/*
> + * Extend this array with ACPI Hardware ID's of devices known to be working
> + * plus the number of link-frequencies expected by their drivers, along with
> + * the frequency values in hertz. This is somewhat opportunistic way of adding
> + * support for this for now in the hopes of a better source for the information
> + * (possibly some encoded value in the SSDB buffer that we're unaware of)
> + * becoming apparent in the future.
> + *
> + * Do not add an entry for a sensor that is not actually supported.
> + */
> +static const struct cio2_sensor_config cio2_supported_sensors[] = {
> +	CIO2_SENSOR_CONFIG("INT33BE", 0),
> +	CIO2_SENSOR_CONFIG("OVTI2680", 0),
> +};
> +
> +static int cio2_bridge_read_acpi_buffer(struct acpi_device *adev, char *id,
> +					void *data, u32 size)
> +{
> +	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
> +	union acpi_object *obj;
> +	acpi_status status;
> +	int ret;
> +
> +	status = acpi_evaluate_object(adev->handle, id, NULL, &buffer);
> +	if (ACPI_FAILURE(status))
> +		return -ENODEV;
> +
> +	obj = buffer.pointer;
> +	if (!obj) {
> +		dev_err(&adev->dev, "Couldn't locate ACPI buffer\n");
> +		return -ENODEV;
> +	}
> +
> +	if (obj->type != ACPI_TYPE_BUFFER) {
> +		dev_err(&adev->dev, "Not an ACPI buffer\n");
> +		ret = -ENODEV;
> +		goto out_free_buff;
> +	}
> +
> +	if (obj->buffer.length > size) {
> +		dev_err(&adev->dev, "Given buffer is too small\n");
> +		ret = -EINVAL;
> +		goto out_free_buff;
> +	}
> +
> +	memcpy(data, obj->buffer.pointer, obj->buffer.length);
> +	ret = obj->buffer.length;
> +
> +out_free_buff:
> +	kfree(buffer.pointer);
> +	return ret;
> +}
> +
> +static void cio2_bridge_init_property_names(struct cio2_sensor *sensor)
> +{
> +	strscpy(sensor->prop_names.clock_frequency, "clock-frequency",
> +		sizeof(sensor->prop_names.clock_frequency));
> +	strscpy(sensor->prop_names.rotation, "rotation",
> +		sizeof(sensor->prop_names.rotation));
> +	strscpy(sensor->prop_names.bus_type, "bus-type",
> +		sizeof(sensor->prop_names.bus_type));
> +	strscpy(sensor->prop_names.data_lanes, "data-lanes",
> +		sizeof(sensor->prop_names.data_lanes));
> +	strscpy(sensor->prop_names.remote_endpoint, "remote-endpoint",
> +		sizeof(sensor->prop_names.remote_endpoint));
> +	strscpy(sensor->prop_names.link_frequencies, "link-frequencies",
> +		sizeof(sensor->prop_names.link_frequencies));

Just curious, was there anything not working correctly with the proposal
I made ?

static const struct cio2_property_names prop_names = {
	.clock_frequency = "clock-frequency",
	.rotation = "rotation",
	.bus_type = "bus-type",
	.data_lanes = "data-lanes",
	.remote_endpoint = "remote-endpoint",
};

static void cio2_bridge_init_property_names(struct cio2_sensor *sensor)
{
	sensor->prop_names = prop_names;
}

It generates a warning when the string is too long for the field size,
which should help catching issues at compilation time.

> +}
> +
> +static void cio2_bridge_create_fwnode_properties(struct cio2_sensor *sensor,
> +						 const struct cio2_sensor_config *cfg)
> +{
> +	unsigned int i;
> +
> +	cio2_bridge_init_property_names(sensor);
> +
> +	for (i = 0; i < 4; i++)
> +		sensor->data_lanes[i] = i + 1;
> +
> +	sensor->local_ref[0].node = &sensor->swnodes[SWNODE_CIO2_ENDPOINT];
> +	sensor->remote_ref[0].node = &sensor->swnodes[SWNODE_SENSOR_ENDPOINT];
> +
> +	sensor->dev_properties[0] = PROPERTY_ENTRY_U32(sensor->prop_names.clock_frequency,
> +						       sensor->ssdb.mclkspeed);
> +	sensor->dev_properties[1] = PROPERTY_ENTRY_U8(sensor->prop_names.rotation,
> +						      sensor->ssdb.degree);
> +
> +	sensor->ep_properties[0] = PROPERTY_ENTRY_U32(sensor->prop_names.bus_type, 4);
> +	sensor->ep_properties[1] = PROPERTY_ENTRY_U32_ARRAY_LEN(sensor->prop_names.data_lanes,
> +								sensor->data_lanes,
> +								sensor->ssdb.lanes);
> +	sensor->ep_properties[2] = PROPERTY_ENTRY_REF_ARRAY(sensor->prop_names.remote_endpoint,
> +							    sensor->local_ref);
> +
> +	if (cfg->nr_link_freqs > 0)
> +		sensor->ep_properties[3] = PROPERTY_ENTRY_U64_ARRAY_LEN(
> +						sensor->prop_names.link_frequencies,
> +						cfg->link_freqs,
> +						cfg->nr_link_freqs);
> +
> +	sensor->cio2_properties[0] = PROPERTY_ENTRY_U32_ARRAY_LEN(sensor->prop_names.data_lanes,
> +								  sensor->data_lanes,
> +								  sensor->ssdb.lanes);
> +	sensor->cio2_properties[1] = PROPERTY_ENTRY_REF_ARRAY(sensor->prop_names.remote_endpoint,
> +							      sensor->remote_ref);
> +}
> +
> +static void cio2_bridge_init_swnode_names(struct cio2_sensor *sensor)
> +{
> +	snprintf(sensor->node_names.remote_port, 7, "port@%u", sensor->ssdb.link);
> +	strscpy(sensor->node_names.port, "port@0", sizeof(sensor->node_names.port));
> +	strscpy(sensor->node_names.endpoint, "endpoint@0", sizeof(sensor->node_names.endpoint));

I'd wrap lines, but maybe that's because I'm an old-school, 80-columns
programmer :-)

> +}
> +
> +static void cio2_bridge_create_connection_swnodes(struct cio2_bridge *bridge,
> +						  struct cio2_sensor *sensor)
> +{
> +	struct software_node *nodes = sensor->swnodes;
> +
> +	cio2_bridge_init_swnode_names(sensor);
> +
> +	nodes[SWNODE_SENSOR_HID] = NODE_SENSOR(sensor->name,
> +					       sensor->dev_properties);
> +	nodes[SWNODE_SENSOR_PORT] = NODE_PORT(sensor->node_names.port,
> +					      &nodes[SWNODE_SENSOR_HID]);
> +	nodes[SWNODE_SENSOR_ENDPOINT] = NODE_ENDPOINT(sensor->node_names.endpoint,
> +						      &nodes[SWNODE_SENSOR_PORT],
> +						      sensor->ep_properties);
> +	nodes[SWNODE_CIO2_PORT] = NODE_PORT(sensor->node_names.remote_port,
> +					    &bridge->cio2_hid_node);
> +	nodes[SWNODE_CIO2_ENDPOINT] = NODE_ENDPOINT(sensor->node_names.endpoint,
> +						    &nodes[SWNODE_CIO2_PORT],
> +						    sensor->cio2_properties);
> +}
> +
> +static void cio2_bridge_unregister_sensors(struct cio2_bridge *bridge)
> +{
> +	struct cio2_sensor *sensor;
> +	unsigned int i;
> +
> +	for (i = 0; i < bridge->n_sensors; i++) {
> +		sensor = &bridge->sensors[i];
> +		software_node_unregister_nodes(sensor->swnodes);
> +		acpi_dev_put(sensor->adev);
> +	}
> +}
> +
> +static int cio2_bridge_connect_sensors(struct cio2_bridge *bridge,
> +				       struct pci_dev *cio2)
> +{
> +	struct fwnode_handle *fwnode;
> +	struct cio2_sensor *sensor;
> +	struct acpi_device *adev;
> +	unsigned int i;
> +	int ret = 0;
> +
> +	for (i = 0; i < ARRAY_SIZE(cio2_supported_sensors); i++) {
> +		const struct cio2_sensor_config *cfg = &cio2_supported_sensors[i];
> +
> +		for_each_acpi_dev_match(adev, cfg->hid, NULL, -1) {
> +			if (bridge->n_sensors >= CIO2_NUM_PORTS) {
> +				dev_warn(&cio2->dev, "Exceeded available CIO2 ports\n");
> +				/* overflow i so outer loop ceases */
> +				i = ARRAY_SIZE(cio2_supported_sensors);
> +				break;

Or just

				return 0;

?

> +			}
> +
> +			if (!adev->status.enabled)
> +				continue;
> +
> +			sensor = &bridge->sensors[bridge->n_sensors];
> +			sensor->adev = adev;
> +			strscpy(sensor->name, cfg->hid, sizeof(sensor->name));
> +
> +			ret = cio2_bridge_read_acpi_buffer(adev, "SSDB",
> +							   &sensor->ssdb,
> +							   sizeof(sensor->ssdb));
> +			if (ret < 0)
> +				goto err_put_adev;
> +
> +			if (sensor->ssdb.lanes > 4) {
> +				dev_err(&adev->dev,
> +					"Number of lanes in SSDB is invalid\n");
> +				goto err_put_adev;
> +			}
> +
> +			cio2_bridge_create_fwnode_properties(sensor, cfg);
> +			cio2_bridge_create_connection_swnodes(bridge, sensor);
> +
> +			ret = software_node_register_nodes(sensor->swnodes);
> +			if (ret)
> +				goto err_put_adev;
> +
> +			fwnode = software_node_fwnode(&sensor->swnodes[SWNODE_SENSOR_HID]);
> +			if (!fwnode) {
> +				ret = -ENODEV;
> +				goto err_free_swnodes;
> +			}
> +
> +			adev->fwnode.secondary = fwnode;
> +
> +			dev_info(&cio2->dev, "Found supported sensor %s\n",
> +				 acpi_dev_name(adev));
> +
> +			bridge->n_sensors++;
> +		}
> +	}
> +
> +	return ret;
> +
> +err_free_swnodes:
> +	software_node_unregister_nodes(sensor->swnodes);
> +err_put_adev:
> +	acpi_dev_put(sensor->adev);
> +
> +	return ret;
> +}
> +
> +int cio2_bridge_init(struct pci_dev *cio2)
> +{
> +	struct device *dev = &cio2->dev;
> +	struct fwnode_handle *fwnode;
> +	struct cio2_bridge *bridge;
> +	int ret;
> +
> +	bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
> +	if (!bridge)
> +		return -ENOMEM;
> +
> +	strscpy(bridge->cio2_node_name, CIO2_HID, sizeof(bridge->cio2_node_name));
> +	bridge->cio2_hid_node.name = bridge->cio2_node_name;
> +
> +	ret = software_node_register(&bridge->cio2_hid_node);
> +	if (ret < 0) {
> +		dev_err(dev, "Failed to register the CIO2 HID node\n");
> +		goto err_free_bridge;
> +	}
> +
> +	ret = cio2_bridge_connect_sensors(bridge, cio2);
> +	if (ret || bridge->n_sensors == 0)
> +		goto err_unregister_cio2;
> +
> +	dev_info(dev, "Connected %d cameras\n", bridge->n_sensors);
> +
> +	fwnode = software_node_fwnode(&bridge->cio2_hid_node);
> +	if (!fwnode) {
> +		dev_err(dev, "Error getting fwnode from cio2 software_node\n");
> +		ret = -ENODEV;
> +		goto err_unregister_sensors;
> +	}
> +
> +	set_secondary_fwnode(dev, fwnode);
> +
> +	return 0;
> +
> +err_unregister_sensors:
> +	cio2_bridge_unregister_sensors(bridge);
> +err_unregister_cio2:
> +	software_node_unregister(&bridge->cio2_hid_node);
> +err_free_bridge:
> +	kfree(bridge);
> +
> +	return ret;
> +}
> diff --git a/drivers/media/pci/intel/ipu3/cio2-bridge.h b/drivers/media/pci/intel/ipu3/cio2-bridge.h
> new file mode 100644
> index 000000000000..f89a8e33f82c
> --- /dev/null
> +++ b/drivers/media/pci/intel/ipu3/cio2-bridge.h
> @@ -0,0 +1,122 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/* Author: Dan Scally <djrscally@gmail.com> */
> +#ifndef __CIO2_BRIDGE_H
> +#define __CIO2_BRIDGE_H
> +
> +#include <linux/property.h>
> +
> +#define CIO2_HID				"INT343E"
> +#define CIO2_NUM_PORTS				4
> +#define MAX_NUM_LINK_FREQS			3
> +
> +#define CIO2_SENSOR_CONFIG(_HID, _NR, ...)	\
> +	{					\
> +		.hid = _HID,			\
> +		.nr_link_freqs = _NR,		\
> +		.link_freqs = { __VA_ARGS__ }	\
> +	}
> +
> +#define NODE_SENSOR(_HID, _PROPS)		\
> +	((const struct software_node) {		\
> +		.name = _HID,			\
> +		.properties = _PROPS,		\
> +	})
> +
> +#define NODE_PORT(_PORT, _SENSOR_NODE)		\
> +	((const struct software_node) {		\
> +		_PORT,				\
> +		_SENSOR_NODE,			\
> +	})
> +
> +#define NODE_ENDPOINT(_EP, _PORT, _PROPS)	\
> +	((const struct software_node) {		\
> +		_EP,				\
> +		_PORT,				\
> +		_PROPS,				\
> +	})
> +
> +enum cio2_sensor_swnodes {
> +	SWNODE_SENSOR_HID,
> +	SWNODE_SENSOR_PORT,
> +	SWNODE_SENSOR_ENDPOINT,
> +	SWNODE_CIO2_PORT,
> +	SWNODE_CIO2_ENDPOINT,
> +	NR_OF_SENSOR_SWNODES
> +};
> +
> +/* Data representation as it is in ACPI SSDB buffer */
> +struct cio2_sensor_ssdb {
> +	u8 version;				/* 0000 */
> +	u8 sku;					/* 0001 */
> +	u8 guid_csi2[16];			/* 0002 */
> +	u8 devfunction;				/* 0003 */
> +	u8 bus;					/* 0004 */
> +	u32 dphylinkenfuses;			/* 0005 */
> +	u32 clockdiv;				/* 0009 */
> +	u8 link;				/* 0013 */
> +	u8 lanes;				/* 0014 */
> +	u32 csiparams[10];			/* 0015 */
> +	u32 maxlanespeed;			/* 0019 */
> +	u8 sensorcalibfileidx;			/* 0023 */
> +	u8 sensorcalibfileidxInMBZ[3];		/* 0024 */
> +	u8 romtype;				/* 0025 */
> +	u8 vcmtype;				/* 0026 */
> +	u8 platforminfo;			/* 0027 */

Why stop at 27 ? :-) I'd either go all the way, or not at all. It's also
quite customary to represent offset as hex values, as that's what most
hex editors / viewers will show.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> +	u8 platformsubinfo;
> +	u8 flash;
> +	u8 privacyled;
> +	u8 degree;
> +	u8 mipilinkdefined;
> +	u32 mclkspeed;
> +	u8 controllogicid;
> +	u8 reserved1[3];
> +	u8 mclkport;
> +	u8 reserved2[13];
> +} __packed;
> +
> +struct cio2_property_names {
> +	char clock_frequency[16];
> +	char rotation[9];
> +	char bus_type[9];
> +	char data_lanes[11];
> +	char remote_endpoint[16];
> +	char link_frequencies[17];
> +};
> +
> +struct cio2_node_names {
> +	char port[7];
> +	char endpoint[11];
> +	char remote_port[7];
> +};
> +
> +struct cio2_sensor_config {
> +	const char *hid;
> +	const u8 nr_link_freqs;
> +	const u64 link_freqs[MAX_NUM_LINK_FREQS];
> +};
> +
> +struct cio2_sensor {
> +	char name[ACPI_ID_LEN];
> +	struct acpi_device *adev;
> +
> +	struct software_node swnodes[6];
> +	struct cio2_node_names node_names;
> +
> +	u32 data_lanes[4];
> +	struct cio2_sensor_ssdb ssdb;
> +	struct cio2_property_names prop_names;
> +	struct property_entry ep_properties[5];
> +	struct property_entry dev_properties[3];
> +	struct property_entry cio2_properties[3];
> +	struct software_node_ref_args local_ref[1];
> +	struct software_node_ref_args remote_ref[1];
> +};
> +
> +struct cio2_bridge {
> +	char cio2_node_name[ACPI_ID_LEN];
> +	struct software_node cio2_hid_node;
> +	unsigned int n_sensors;
> +	struct cio2_sensor sensors[CIO2_NUM_PORTS];
> +};
> +
> +#endif
> diff --git a/drivers/media/pci/intel/ipu3/ipu3-cio2-main.c b/drivers/media/pci/intel/ipu3/ipu3-cio2-main.c
> index 36e354ecf71e..68ff28abc6a3 100644
> --- a/drivers/media/pci/intel/ipu3/ipu3-cio2-main.c
> +++ b/drivers/media/pci/intel/ipu3/ipu3-cio2-main.c
> @@ -1702,11 +1702,28 @@ static void cio2_queues_exit(struct cio2_device *cio2)
>  		cio2_queue_exit(cio2, &cio2->queue[i]);
>  }
>  
> +static bool cio2_check_fwnode_graph(struct fwnode_handle *fwnode)
> +{
> +	struct fwnode_handle *endpoint;
> +
> +	if (IS_ERR_OR_NULL(fwnode))
> +		return false;
> +
> +	endpoint = fwnode_graph_get_next_endpoint(fwnode, NULL);
> +	if (endpoint) {
> +		fwnode_handle_put(endpoint);
> +		return true;
> +	}
> +
> +	return cio2_check_fwnode_graph(fwnode->secondary);
> +}
> +
>  /**************** PCI interface ****************/
>  
>  static int cio2_pci_probe(struct pci_dev *pci_dev,
>  			  const struct pci_device_id *id)
>  {
> +	struct fwnode_handle *fwnode = dev_fwnode(&pci_dev->dev);
>  	struct cio2_device *cio2;
>  	int r;
>  
> @@ -1715,6 +1732,23 @@ static int cio2_pci_probe(struct pci_dev *pci_dev,
>  		return -ENOMEM;
>  	cio2->pci_dev = pci_dev;
>  
> +	/*
> +	 * On some platforms no connections to sensors are defined in firmware,
> +	 * if the device has no endpoints then we can try to build those as
> +	 * software_nodes parsed from SSDB.
> +	 */
> +	if (!cio2_check_fwnode_graph(fwnode)) {
> +		if (fwnode && !IS_ERR_OR_NULL(fwnode->secondary)) {
> +			dev_err(&pci_dev->dev,
> +				"fwnode graph has no endpoints connected\n");
> +			return -EINVAL;
> +		}
> +
> +		r = cio2_bridge_init(pci_dev);
> +		if (r)
> +			return r;
> +	}
> +
>  	r = pcim_enable_device(pci_dev);
>  	if (r) {
>  		dev_err(&pci_dev->dev, "failed to enable device (%d)\n", r);
> diff --git a/drivers/media/pci/intel/ipu3/ipu3-cio2.h b/drivers/media/pci/intel/ipu3/ipu3-cio2.h
> index ccf0b85ae36f..520a27c9cdad 100644
> --- a/drivers/media/pci/intel/ipu3/ipu3-cio2.h
> +++ b/drivers/media/pci/intel/ipu3/ipu3-cio2.h
> @@ -437,4 +437,10 @@ static inline struct cio2_queue *vb2q_to_cio2_queue(struct vb2_queue *vq)
>  	return container_of(vq, struct cio2_queue, vbq);
>  }
>  
> +#if IS_ENABLED(CONFIG_CIO2_BRIDGE)
> +int cio2_bridge_init(struct pci_dev *cio2);
> +#else
> +int cio2_bridge_init(struct pci_dev *cio2) { return 0; }
> +#endif
> +
>  #endif
Andy Shevchenko Dec. 18, 2020, 8:29 p.m. UTC | #3
On Thu, Dec 17, 2020 at 11:43:29PM +0000, Daniel Scally wrote:
> Registering software_nodes with the .parent member set to point to a

> currently unregistered software_node has the potential for problems,

> so enforce parent -> child ordering in arrays passed in to

> software_node_register_nodes().

> 

> Software nodes that are children of another software node should be

> unregistered before their parent. To allow easy unregistering of an array

> of software_nodes ordered parent to child, reverse the order in which

> software_node_unregister_nodes() unregisters software_nodes.


...

> + * Register multiple software nodes at once. If any node in the array

> + * has it's .parent pointer set, then it's parent **must** have been


it's => its in both cases?


> + * registered before it is; either outside of this function or by

> + * ordering the array such that parent comes before child.

>   */


...

> +		const struct software_node *parent = nodes[i].parent;

> +

> +		if (parent && !software_node_to_swnode(parent)) {


Can we have parent of swnode in an array not being an swnode?
Either comment that parent for swnode can be swnode only (Heikki, was it an
idea?) or check if parent is of swnode type and only that apply this
requirement.

> +			ret = -EINVAL;

> +			goto err_unregister_nodes;

>  		}


...

> + * Unregister multiple software nodes at once. If parent pointers are set up

> + * in any of the software nodes then the array MUST be ordered such that

> + * parents come before their children.


Shouldn't be consistent with above, i.e. **must** ?

-- 
With Best Regards,
Andy Shevchenko
Andy Shevchenko Dec. 18, 2020, 8:31 p.m. UTC | #4
On Thu, Dec 17, 2020 at 11:43:30PM +0000, Daniel Scally wrote:
> To maintain consistency with software_node_unregister_nodes(), reverse

> the order in which the software_node_unregister_node_group() function

> unregisters nodes.


...

> + * Unregister multiple software nodes at once. The array will be unwound in

> + * reverse order (I.E. last entry first) and thus if any member of the array


A nit: I.E. -> i.e.

> + * has its .parent member set then they should appear later in the array such

> + * that they are unregistered first.


-- 
With Best Regards,
Andy Shevchenko
Daniel Scally Dec. 18, 2020, 10:19 p.m. UTC | #5
Hi Laurent

On 18/12/2020 16:02, Laurent Pinchart wrote:
> Hi Daniel,

> 

> Thank you for the patch.

> 

> On Thu, Dec 17, 2020 at 11:43:29PM +0000, Daniel Scally wrote:

>> Registering software_nodes with the .parent member set to point to a

>> currently unregistered software_node has the potential for problems,

>> so enforce parent -> child ordering in arrays passed in to

>> software_node_register_nodes().

>>

>> Software nodes that are children of another software node should be

>> unregistered before their parent. To allow easy unregistering of an array

>> of software_nodes ordered parent to child, reverse the order in which

>> software_node_unregister_nodes() unregisters software_nodes.

>>

>> Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

>> Signed-off-by: Daniel Scally <djrscally@gmail.com>

>> ---

>> Changes in v2:

>>

>> 	- Squashed the patches that originally touched these separately

>> 	- Updated documentation

>>

>>  drivers/base/swnode.c | 43 ++++++++++++++++++++++++++++++-------------

>>  1 file changed, 30 insertions(+), 13 deletions(-)

>>

>> diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c

>> index 615a0c93e116..cfd1faea48a7 100644

>> --- a/drivers/base/swnode.c

>> +++ b/drivers/base/swnode.c

>> @@ -692,7 +692,10 @@ swnode_register(const struct software_node *node, struct swnode *parent,

>>   * software_node_register_nodes - Register an array of software nodes

>>   * @nodes: Zero terminated array of software nodes to be registered

>>   *

>> - * Register multiple software nodes at once.

>> + * Register multiple software nodes at once. If any node in the array

>> + * has it's .parent pointer set, then it's parent **must** have been

>> + * registered before it is; either outside of this function or by

>> + * ordering the array such that parent comes before child.

>>   */

>>  int software_node_register_nodes(const struct software_node *nodes)

>>  {

>> @@ -700,33 +703,47 @@ int software_node_register_nodes(const struct software_node *nodes)

>>  	int i;

>>  

>>  	for (i = 0; nodes[i].name; i++) {

>> -		ret = software_node_register(&nodes[i]);

>> -		if (ret) {

>> -			software_node_unregister_nodes(nodes);

>> -			return ret;

>> +		const struct software_node *parent = nodes[i].parent;

>> +

>> +		if (parent && !software_node_to_swnode(parent)) {

>> +			ret = -EINVAL;

>> +			goto err_unregister_nodes;

>>  		}

>> +

>> +		ret = software_node_register(&nodes[i]);

>> +		if (ret)

>> +			goto err_unregister_nodes;

>>  	}

>>  

>>  	return 0;

>> +

>> +err_unregister_nodes:

>> +	software_node_unregister_nodes(nodes);

>> +	return ret;

>>  }

>>  EXPORT_SYMBOL_GPL(software_node_register_nodes);

>>  

>>  /**

>>   * software_node_unregister_nodes - Unregister an array of software nodes

>> - * @nodes: Zero terminated array of software nodes to be unregistered

>> + * @nodes: Zero terminated array of software nodes to be unregistered.

> 

> Not sure if this is needed.


Hah, of course. Hangover from the last version (when I had made that
line two sentences)
> 

>>   *

>> - * Unregister multiple software nodes at once.

>> + * Unregister multiple software nodes at once. If parent pointers are set up

>> + * in any of the software nodes then the array MUST be ordered such that

> 

> I'd either replace **must** above with MUST, or use **must** here. I'm

> not sure if kerneldoc handles emphasis with **must**, if it does that

> seems a bit nicer to me, but it's really up to you.


Honestly I haven't delved into kerneldoc yet, but either way I think
**must** is better in both places - will change.

> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>


Thank you!
> 

>> + * parents come before their children.

>>   *

>> - * NOTE: Be careful using this call if the nodes had parent pointers set up in

>> - * them before registering.  If so, it is wiser to remove the nodes

>> - * individually, in the correct order (child before parent) instead of relying

>> - * on the sequential order of the list of nodes in the array.

>> + * NOTE: If you are uncertain whether the array is ordered such that

>> + * parents will be unregistered before their children, it is wiser to

>> + * remove the nodes individually, in the correct order (child before

>> + * parent).

>>   */

>>  void software_node_unregister_nodes(const struct software_node *nodes)

>>  {

>> -	int i;

>> +	unsigned int i = 0;

>> +

>> +	while (nodes[i].name)

>> +		i++;

>>  

>> -	for (i = 0; nodes[i].name; i++)

>> +	while (i--)

>>  		software_node_unregister(&nodes[i]);

>>  }

>>  EXPORT_SYMBOL_GPL(software_node_unregister_nodes);

>
Daniel Scally Dec. 18, 2020, 11:57 p.m. UTC | #6
Hi Laurent - thanks for the comments

On 18/12/2020 16:53, Laurent Pinchart wrote:
>> +static void cio2_bridge_init_property_names(struct cio2_sensor *sensor)
>> +{
>> +	strscpy(sensor->prop_names.clock_frequency, "clock-frequency",
>> +		sizeof(sensor->prop_names.clock_frequency));
>> +	strscpy(sensor->prop_names.rotation, "rotation",
>> +		sizeof(sensor->prop_names.rotation));
>> +	strscpy(sensor->prop_names.bus_type, "bus-type",
>> +		sizeof(sensor->prop_names.bus_type));
>> +	strscpy(sensor->prop_names.data_lanes, "data-lanes",
>> +		sizeof(sensor->prop_names.data_lanes));
>> +	strscpy(sensor->prop_names.remote_endpoint, "remote-endpoint",
>> +		sizeof(sensor->prop_names.remote_endpoint));
>> +	strscpy(sensor->prop_names.link_frequencies, "link-frequencies",
>> +		sizeof(sensor->prop_names.link_frequencies));
> 
> Just curious, was there anything not working correctly with the proposal
> I made ?
> 
> static const struct cio2_property_names prop_names = {
> 	.clock_frequency = "clock-frequency",
> 	.rotation = "rotation",
> 	.bus_type = "bus-type",
> 	.data_lanes = "data-lanes",
> 	.remote_endpoint = "remote-endpoint",
> };
> 
> static void cio2_bridge_init_property_names(struct cio2_sensor *sensor)
> {
> 	sensor->prop_names = prop_names;
> }
> 
> It generates a warning when the string is too long for the field size,
> which should help catching issues at compilation time.

Yes, though I don't know how much of a real-world problem it would have
been - if you recall we have the issue that the device grabs a reference
to the software_nodes (after we stopped delaying until after the
i2c_client is available), which means we can't safely free the
cio2_bridge struct on module unload. That also means we can't rely on
those pointers to string literals existing, because if the ipu3-cio2
module gets unloaded they'll be gone.

Shame, as it's way neater.

>> +static void cio2_bridge_init_swnode_names(struct cio2_sensor *sensor)
>> +{
>> +	snprintf(sensor->node_names.remote_port, 7, "port@%u", sensor->ssdb.link);
>> +	strscpy(sensor->node_names.port, "port@0", sizeof(sensor->node_names.port));
>> +	strscpy(sensor->node_names.endpoint, "endpoint@0", sizeof(sensor->node_names.endpoint));
> 
> I'd wrap lines, but maybe that's because I'm an old-school, 80-columns
> programmer :-)

Heh sure, I'll wrap them.

>> +static int cio2_bridge_connect_sensors(struct cio2_bridge *bridge,
>> +				       struct pci_dev *cio2)
>> +{
>> +	struct fwnode_handle *fwnode;
>> +	struct cio2_sensor *sensor;
>> +	struct acpi_device *adev;
>> +	unsigned int i;
>> +	int ret = 0;
>> +
>> +	for (i = 0; i < ARRAY_SIZE(cio2_supported_sensors); i++) {
>> +		const struct cio2_sensor_config *cfg = &cio2_supported_sensors[i];
>> +
>> +		for_each_acpi_dev_match(adev, cfg->hid, NULL, -1) {
>> +			if (bridge->n_sensors >= CIO2_NUM_PORTS) {
>> +				dev_warn(&cio2->dev, "Exceeded available CIO2 ports\n");
>> +				/* overflow i so outer loop ceases */
>> +				i = ARRAY_SIZE(cio2_supported_sensors);
>> +				break;
> 
> Or just
> 
> 				return 0;
> 
> ?

Derp, yes of course.


>> +/* Data representation as it is in ACPI SSDB buffer */
>> +struct cio2_sensor_ssdb {
>> +	u8 version;				/* 0000 */
>> +	u8 sku;					/* 0001 */
>> +	u8 guid_csi2[16];			/* 0002 */
>> +	u8 devfunction;				/* 0003 */
>> +	u8 bus;					/* 0004 */
>> +	u32 dphylinkenfuses;			/* 0005 */
>> +	u32 clockdiv;				/* 0009 */
>> +	u8 link;				/* 0013 */
>> +	u8 lanes;				/* 0014 */
>> +	u32 csiparams[10];			/* 0015 */
>> +	u32 maxlanespeed;			/* 0019 */
>> +	u8 sensorcalibfileidx;			/* 0023 */
>> +	u8 sensorcalibfileidxInMBZ[3];		/* 0024 */
>> +	u8 romtype;				/* 0025 */
>> +	u8 vcmtype;				/* 0026 */
>> +	u8 platforminfo;			/* 0027 */
> 
> Why stop at 27 ? :-) I'd either go all the way, or not at all. It's also
> quite customary to represent offset as hex values, as that's what most
> hex editors / viewers will show.

Oops - that was actually just me debugging...I guess I might actually
finish it, converted to hex. It came in useful reading the DSDT to have
that somewhere easy to refer to.

> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Nice - thank you!
Laurent Pinchart Dec. 19, 2020, 12:39 a.m. UTC | #7
Hi Daniel,

On Fri, Dec 18, 2020 at 11:57:54PM +0000, Daniel Scally wrote:
> Hi Laurent - thanks for the comments

> 

> On 18/12/2020 16:53, Laurent Pinchart wrote:

> >> +static void cio2_bridge_init_property_names(struct cio2_sensor *sensor)

> >> +{

> >> +	strscpy(sensor->prop_names.clock_frequency, "clock-frequency",

> >> +		sizeof(sensor->prop_names.clock_frequency));

> >> +	strscpy(sensor->prop_names.rotation, "rotation",

> >> +		sizeof(sensor->prop_names.rotation));

> >> +	strscpy(sensor->prop_names.bus_type, "bus-type",

> >> +		sizeof(sensor->prop_names.bus_type));

> >> +	strscpy(sensor->prop_names.data_lanes, "data-lanes",

> >> +		sizeof(sensor->prop_names.data_lanes));

> >> +	strscpy(sensor->prop_names.remote_endpoint, "remote-endpoint",

> >> +		sizeof(sensor->prop_names.remote_endpoint));

> >> +	strscpy(sensor->prop_names.link_frequencies, "link-frequencies",

> >> +		sizeof(sensor->prop_names.link_frequencies));

> > 

> > Just curious, was there anything not working correctly with the proposal

> > I made ?

> > 

> > static const struct cio2_property_names prop_names = {

> > 	.clock_frequency = "clock-frequency",

> > 	.rotation = "rotation",

> > 	.bus_type = "bus-type",

> > 	.data_lanes = "data-lanes",

> > 	.remote_endpoint = "remote-endpoint",

> > };

> > 

> > static void cio2_bridge_init_property_names(struct cio2_sensor *sensor)

> > {

> > 	sensor->prop_names = prop_names;

> > }

> > 

> > It generates a warning when the string is too long for the field size,

> > which should help catching issues at compilation time.

> 

> Yes, though I don't know how much of a real-world problem it would have

> been - if you recall we have the issue that the device grabs a reference

> to the software_nodes (after we stopped delaying until after the

> i2c_client is available), which means we can't safely free the

> cio2_bridge struct on module unload. That also means we can't rely on

> those pointers to string literals existing, because if the ipu3-cio2

> module gets unloaded they'll be gone.


But the strings above are not stored as literals in .rodata, they're
copied in prop_names (itself in .rodata), which is then copied to
sensor->prop_names.

> Shame, as it's way neater.

> 

> >> +static void cio2_bridge_init_swnode_names(struct cio2_sensor *sensor)

> >> +{

> >> +	snprintf(sensor->node_names.remote_port, 7, "port@%u", sensor->ssdb.link);

> >> +	strscpy(sensor->node_names.port, "port@0", sizeof(sensor->node_names.port));

> >> +	strscpy(sensor->node_names.endpoint, "endpoint@0", sizeof(sensor->node_names.endpoint));

> > 

> > I'd wrap lines, but maybe that's because I'm an old-school, 80-columns

> > programmer :-)

> 

> Heh sure, I'll wrap them.

> 

> >> +static int cio2_bridge_connect_sensors(struct cio2_bridge *bridge,

> >> +				       struct pci_dev *cio2)

> >> +{

> >> +	struct fwnode_handle *fwnode;

> >> +	struct cio2_sensor *sensor;

> >> +	struct acpi_device *adev;

> >> +	unsigned int i;

> >> +	int ret = 0;

> >> +

> >> +	for (i = 0; i < ARRAY_SIZE(cio2_supported_sensors); i++) {

> >> +		const struct cio2_sensor_config *cfg = &cio2_supported_sensors[i];

> >> +

> >> +		for_each_acpi_dev_match(adev, cfg->hid, NULL, -1) {

> >> +			if (bridge->n_sensors >= CIO2_NUM_PORTS) {

> >> +				dev_warn(&cio2->dev, "Exceeded available CIO2 ports\n");

> >> +				/* overflow i so outer loop ceases */

> >> +				i = ARRAY_SIZE(cio2_supported_sensors);

> >> +				break;

> > 

> > Or just

> > 

> > 				return 0;

> > 

> > ?

> 

> Derp, yes of course.

> 

> 

> >> +/* Data representation as it is in ACPI SSDB buffer */

> >> +struct cio2_sensor_ssdb {

> >> +	u8 version;				/* 0000 */

> >> +	u8 sku;					/* 0001 */

> >> +	u8 guid_csi2[16];			/* 0002 */

> >> +	u8 devfunction;				/* 0003 */

> >> +	u8 bus;					/* 0004 */

> >> +	u32 dphylinkenfuses;			/* 0005 */

> >> +	u32 clockdiv;				/* 0009 */

> >> +	u8 link;				/* 0013 */

> >> +	u8 lanes;				/* 0014 */

> >> +	u32 csiparams[10];			/* 0015 */

> >> +	u32 maxlanespeed;			/* 0019 */

> >> +	u8 sensorcalibfileidx;			/* 0023 */

> >> +	u8 sensorcalibfileidxInMBZ[3];		/* 0024 */

> >> +	u8 romtype;				/* 0025 */

> >> +	u8 vcmtype;				/* 0026 */

> >> +	u8 platforminfo;			/* 0027 */

> > 

> > Why stop at 27 ? :-) I'd either go all the way, or not at all. It's also

> > quite customary to represent offset as hex values, as that's what most

> > hex editors / viewers will show.

> 

> Oops - that was actually just me debugging...I guess I might actually

> finish it, converted to hex. It came in useful reading the DSDT to have

> that somewhere easy to refer to.

> 

> > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> 

> Nice - thank you!


-- 
Regards,

Laurent Pinchart
Daniel Scally Dec. 19, 2020, 11:24 p.m. UTC | #8
On 19/12/2020 00:39, Laurent Pinchart wrote:
> Hi Daniel,

> 

> On Fri, Dec 18, 2020 at 11:57:54PM +0000, Daniel Scally wrote:

>> Hi Laurent - thanks for the comments

>>

>> On 18/12/2020 16:53, Laurent Pinchart wrote:

>>>> +static void cio2_bridge_init_property_names(struct cio2_sensor *sensor)

>>>> +{

>>>> +	strscpy(sensor->prop_names.clock_frequency, "clock-frequency",

>>>> +		sizeof(sensor->prop_names.clock_frequency));

>>>> +	strscpy(sensor->prop_names.rotation, "rotation",

>>>> +		sizeof(sensor->prop_names.rotation));

>>>> +	strscpy(sensor->prop_names.bus_type, "bus-type",

>>>> +		sizeof(sensor->prop_names.bus_type));

>>>> +	strscpy(sensor->prop_names.data_lanes, "data-lanes",

>>>> +		sizeof(sensor->prop_names.data_lanes));

>>>> +	strscpy(sensor->prop_names.remote_endpoint, "remote-endpoint",

>>>> +		sizeof(sensor->prop_names.remote_endpoint));

>>>> +	strscpy(sensor->prop_names.link_frequencies, "link-frequencies",

>>>> +		sizeof(sensor->prop_names.link_frequencies));

>>>

>>> Just curious, was there anything not working correctly with the proposal

>>> I made ?

>>>

>>> static const struct cio2_property_names prop_names = {

>>> 	.clock_frequency = "clock-frequency",

>>> 	.rotation = "rotation",

>>> 	.bus_type = "bus-type",

>>> 	.data_lanes = "data-lanes",

>>> 	.remote_endpoint = "remote-endpoint",

>>> };

>>>

>>> static void cio2_bridge_init_property_names(struct cio2_sensor *sensor)

>>> {

>>> 	sensor->prop_names = prop_names;

>>> }

>>>

>>> It generates a warning when the string is too long for the field size,

>>> which should help catching issues at compilation time.

>>

>> Yes, though I don't know how much of a real-world problem it would have

>> been - if you recall we have the issue that the device grabs a reference

>> to the software_nodes (after we stopped delaying until after the

>> i2c_client is available), which means we can't safely free the

>> cio2_bridge struct on module unload. That also means we can't rely on

>> those pointers to string literals existing, because if the ipu3-cio2

>> module gets unloaded they'll be gone.

> 

> But the strings above are not stored as literals in .rodata, they're

> copied in prop_names (itself in .rodata), which is then copied to

> sensor->prop_names.


Yeah, my bad; I also had changed the struct definition to:

struct cio2_property_names {
	char *clock_frequency;
	...
};

And that behaves differently - apologies. I'll change to your proposal.
Daniel Scally Dec. 19, 2020, 11:33 p.m. UTC | #9
On 18/12/2020 20:29, Andy Shevchenko wrote:
>> + * Register multiple software nodes at once. If any node in the array

>> + * has it's .parent pointer set, then it's parent **must** have been

> 

> it's => its in both cases?


Done, ty

>> + * registered before it is; either outside of this function or by

>> + * ordering the array such that parent comes before child.

>>   */

> 

> ...

> 

>> +		const struct software_node *parent = nodes[i].parent;

>> +

>> +		if (parent && !software_node_to_swnode(parent)) {

> 

> Can we have parent of swnode in an array not being an swnode?

> Either comment that parent for swnode can be swnode only (Heikki, was it an

> idea?) or check if parent is of swnode type and only that apply this

> requirement.


.parent can be a pointer to software_node only yes; I can add that to
the document comment.

>> +			ret = -EINVAL;

>> +			goto err_unregister_nodes;

>>  		}

> 

> ...

> 

>> + * Unregister multiple software nodes at once. If parent pointers are set up

>> + * in any of the software nodes then the array MUST be ordered such that

>> + * parents come before their children.

> 

> Shouldn't be consistent with above, i.e. **must** ?


Done also