Re: [PATCH v3 14/14] ipu3-cio2: Add cio2-bridge to ipu3-cio2 driver

[Andy Shevchenko <andy.shevchenko@gmail.com>]

On Thu, Dec 24, 2020 at 3:12 AM Daniel Scally <djrscally@gmail.com> 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.

Few nitpicks below, after addressing them
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

> Suggested-by: Jordan Hand <jorhand@linux.microsoft.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Signed-off-by: Daniel Scally <djrscally@gmail.com>
> ---
> Changes in v3
>         - Used Laurent's suggestion to simplify initing the property names
>         - Wrapped some lines
>         - Fixed return and error handling for cio2_bridge_read_acpi_buffer()
>         - Returned an error if more sensors than available ports are detected
>         - Used defines for port/endpoint name formats and the bus-type property
>         - Some bits of cleanup
>
>  MAINTAINERS                                   |   1 +
>  drivers/media/pci/intel/ipu3/Kconfig          |  18 ++
>  drivers/media/pci/intel/ipu3/Makefile         |   1 +
>  drivers/media/pci/intel/ipu3/cio2-bridge.c    | 272 ++++++++++++++++++
>  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, 454 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

in the

> +         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..3f4ae172fd25
> --- /dev/null
> +++ b/drivers/media/pci/intel/ipu3/cio2-bridge.c
> @@ -0,0 +1,272 @@
> +// 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 <media/v4l2-fwnode.h>
> +
> +#include "cio2-bridge.h"
> +
> +/*
> + * Extend this array with ACPI Hardware ID's of devices known to be working

ID's -> IDs ?

> + * 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 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",
> +       .link_frequencies = "link-frequencies",
> +};
> +
> +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 = 0;
> +
> +       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);
> +
> +out_free_buff:
> +       kfree(buffer.pointer);
> +       return ret;
> +}
> +
> +static void cio2_bridge_create_fwnode_properties(struct cio2_sensor *sensor,
> +                                                const struct cio2_sensor_config *cfg)
> +{
> +       unsigned int i;
> +
> +       sensor->prop_names = prop_names;
> +
> +       for (i = 0; i < 4; i++)

4 here and below, can we have a local define for them, like

  #define CIO2_MAX_LANES  4

> +               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,
> +                                                     V4L2_FWNODE_BUS_TYPE_CSI2_DPHY);
> +       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, sizeof(sensor->node_names.remote_port),
> +                FWNODE_GRAPH_PORT_NAME_FORMAT, sensor->ssdb.link);
> +       snprintf(sensor->node_names.port, sizeof(sensor->node_names.port),
> +                FWNODE_GRAPH_PORT_NAME_FORMAT, 0); /* Always port 0 */
> +       snprintf(sensor->node_names.endpoint, sizeof(sensor->node_names.endpoint),
> +                FWNODE_GRAPH_ENDPOINT_NAME_FORMAT, 0); /* And endpoint 0 */
> +}
> +
> +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;

You may drop this assignment and...

> +       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_err(&cio2->dev, "Exceeded available CIO2 ports\n");
> +                               cio2_bridge_unregister_sensors(bridge);
> +                               ret = -EINVAL;
> +                               goto err_out;
> +                       }
> +
> +                       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)
> +                               goto err_put_adev;
> +
> +                       if (sensor->ssdb.lanes > 4) {

CIO2_MAX_LANES

> +                               dev_err(&adev->dev,
> +                                       "Number of lanes in SSDB is invalid\n");
> +                               ret = -EINVAL;
> +                               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;

...use here

  return 0;

directly.

> +err_free_swnodes:
> +       software_node_unregister_nodes(sensor->swnodes);
> +err_put_adev:
> +       acpi_dev_put(sensor->adev);
> +err_out:
> +       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..004b608f322f
> --- /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,

> +       SWNODE_COUNT,

No comma?

> +};
> +
> +/* Data representation as it is in ACPI SSDB buffer */
> +struct cio2_sensor_ssdb {
> +       u8 version;
> +       u8 sku;
> +       u8 guid_csi2[16];
> +       u8 devfunction;
> +       u8 bus;
> +       u32 dphylinkenfuses;
> +       u32 clockdiv;
> +       u8 link;
> +       u8 lanes;
> +       u32 csiparams[10];
> +       u32 maxlanespeed;
> +       u8 sensorcalibfileidx;
> +       u8 sensorcalibfileidxInMBZ[3];
> +       u8 romtype;
> +       u8 vcmtype;
> +       u8 platforminfo;
> +       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");

One line?

> +                       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
> --
> 2.25.1
>


-- 
With Best Regards,
Andy Shevchenko