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

From: Daniel Scally
Date: Wed Dec 23 2020 - 20:11:18 EST

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@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Signed-off-by: Daniel Scally <djrscally@xxxxxxxxx>
---
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@xxxxxxxxx>
M: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
M: Bingbu Cao <bingbu.cao@xxxxxxxxx>
+M: Dan Scally <djrscally@xxxxxxxxx>
R: Tianshu Qiu <tian.shu.qiu@xxxxxxxxx>
L: linux-media@xxxxxxxxxxxxxxx
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..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@xxxxxxxxx> */
+
+#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
+ * 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++)
+ 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;
+
+ 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) {
+ 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;
+
+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@xxxxxxxxx> */
+#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,
+};
+
+/* 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");
+ 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