[PATCH v2 0/6] ACPI: scan: MIPI DiSco for Imaging support

[PATCH v2 0/6] ACPI: scan: MIPI DiSco for Imaging support

[Rafael J. Wysocki]

Hi Folks,

This is a new revision of

https://lore.kernel.org/linux-acpi/13276375.uLZWGnKmhe@kreacher/

which was reported to have issues and it took time to revisit it.

> The main points from the original cover letter are still valid:
> 
> The general idea is the same - CSI-2 resource descriptors, introduced in
> ACPI 6.4 and defined by
> 
> https://uefi.org/specs/ACPI/6.5/06_Device_Configuration.html#camera-serial-i
> nterface-csi-2-connection-resource-descriptor
> 
> are found and used for creating a set of software nodes that represent the
> CSI-2 connection graph.
> 
> These software nodes need to be available before any scan handlers or ACPI
> drivers are bound to any struct acpi_device objects, so all of that is done
> at the early stage of ACPI device enumeration, but unnecessary ACPI
> namespace walks are avoided.
> 
> The CSI-2 software nodes are populated with data extracted from the CSI-2
> resource descriptors themselves and from device properties defined by the
> MIPI DiSco for Imaging specification (see
> https://www.mipi.org/specifications/mipi-disco-imaging).
> 
> Patches [4,6/6] come from the original series directly, but the other
> patches have been changes substantially, so I've decided to re-start patch
> series versioning from scratch.

The v2 addresses at least 3 issues found in the v1 by code inspection:

* A port_count field incrementation was missing in acpi_mipi_scan_crs_csi2(),
  so its value for all of the devices having CSI2 resources in _CRS was always
  1 (and it should be equal to the number of valid CSI2 connection resources).

* Some acpi_mipi_crs_csi2_list members could be freed prematurely, so they were
  inaccessible when extract_crs_csi2_conn_info() attempted to access them.

* A check of remote_swnodes() against NULL was missing, which could result in
  a crash in a case when the swnodes memory could not be allocated for some
  acpi_mipi_crs_csi2_list entries.

Apart from that, it rearranges the code somewhat to make it easier to follow
and to avoid premature freeing of memory in it in general and the new file
added by it is now called mipi-di.c (instead of mipi-disco-imaging.c) for
compactness.

The series is based on current linux-next.

Thanks!

[PATCH v2 1/6] ACPI: property: Support using strings in reference properties

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

In order to allow referencing data nodes directly, which is not possible
currently, add support for representing references in device properties
as strings (relative or absolute name paths).  For example, after this
change, the "mipi-img-flash-leds" property in the ASL snippet below will
be treated as a proper reference to the LED0 object under LEDD.

 Package ()
 {
     "mipi-img-flash-leds",  "\\_SB.PCI0.I2C2.LEDD.LED0",
 }

 Device (LEDD)
 {
     Name (_DSD, Package ()  // _DSD: Device-Specific Data
     {
         ToUUID ("dbb8e3e6-5886-4ba6-8795-1319f52a966b"), /* Hierarchical Data Extension */,
         Package ()
         {
             Package ()
             {
                 "mipi-img-flash-led-0", 
                 "LED0",
             }
         },
     })
     Name (LED0, Package ()  // _DSD: Device-Specific Data
     {
         ToUUID ("daffd814-6eba-4d8c-8a91-bc9bbf4aa301") /* Device Properties */,
         Package ()
         {
             Package ()
             {
                 "mipi-img-max-current", 
                 1000000,
             }
         }
     })
 }

Also remove the mechanism allowing data nodes to be referenced
indirectly, with the help of an object reference pointing to the
"ancestor" device and a path relative to it (this mechanism is not
expected to be in use in any production platform firmware in the field).

Note that this change allows also using strings for referencing device
objects, in addition to object references that have been supported
already.

While at it, add pr_fmt() macro to prefix printouts and update
copyright.

Co-developed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/acpi/property.c |  102 ++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 82 insertions(+), 20 deletions(-)

Index: linux-pm/drivers/acpi/property.c
===================================================================
--- linux-pm.orig/drivers/acpi/property.c
+++ linux-pm/drivers/acpi/property.c
@@ -2,14 +2,17 @@
 /*
  * ACPI device specific properties support.
  *
- * Copyright (C) 2014, Intel Corporation
+ * Copyright (C) 2014 - 2023, Intel Corporation
  * All rights reserved.
  *
  * Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
  *          Darren Hart <dvhart@linux.intel.com>
  *          Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+ *          Sakari Ailus <sakari.ailus@linux.intel.com>
  */
 
+#define pr_fmt(fmt) "ACPI: " fmt
+
 #include <linux/acpi.h>
 #include <linux/device.h>
 #include <linux/export.h>
@@ -801,27 +804,15 @@ static int acpi_get_ref_args(struct fwno
 	u32 nargs = 0, i;
 
 	/*
-	 * Find the referred data extension node under the
-	 * referred device node.
-	 */
-	for (; *element < end && (*element)->type == ACPI_TYPE_STRING;
-	     (*element)++) {
-		const char *child_name = (*element)->string.pointer;
-
-		ref_fwnode = acpi_fwnode_get_named_child_node(ref_fwnode, child_name);
-		if (!ref_fwnode)
-			return -EINVAL;
-	}
-
-	/*
 	 * Assume the following integer elements are all args. Stop counting on
-	 * the first reference or end of the package arguments. In case of
-	 * neither reference, nor integer, return an error, we can't parse it.
+	 * the first reference (possibly represented as a string) or end of the
+	 * package arguments. In case of neither reference, nor integer, return
+	 * an error, we can't parse it.
 	 */
 	for (i = 0; (*element) + i < end && i < num_args; i++) {
 		acpi_object_type type = (*element)[i].type;
 
-		if (type == ACPI_TYPE_LOCAL_REFERENCE)
+		if (type == ACPI_TYPE_LOCAL_REFERENCE || type == ACPI_TYPE_STRING)
 			break;
 
 		if (type == ACPI_TYPE_INTEGER)
@@ -845,6 +836,44 @@ static int acpi_get_ref_args(struct fwno
 	return 0;
 }
 
+static struct fwnode_handle *acpi_parse_string_ref(const struct fwnode_handle *fwnode,
+						   const char *refstring)
+{
+	acpi_handle scope, handle;
+	struct acpi_data_node *dn;
+	struct acpi_device *device;
+	acpi_status status;
+
+	if (is_acpi_device_node(fwnode)) {
+		scope = to_acpi_device_node(fwnode)->handle;
+	} else if (is_acpi_data_node(fwnode)) {
+		scope = to_acpi_data_node(fwnode)->handle;
+	} else {
+		pr_debug("Bad node type for node %pfw\n", fwnode);
+		return NULL;
+	}
+
+	status = acpi_get_handle(scope, refstring, &handle);
+	if (ACPI_FAILURE(status)) {
+		acpi_handle_debug(scope, "Unable to get an ACPI handle for %s\n",
+				  refstring);
+		return NULL;
+	}
+
+	device = acpi_fetch_acpi_dev(handle);
+	if (device)
+		return acpi_fwnode_handle(device);
+
+	status = acpi_get_data_full(handle, acpi_nondev_subnode_tag,
+				    (void **)&dn, NULL);
+	if (ACPI_FAILURE(status) || !dn) {
+		acpi_handle_debug(handle, "Subnode not found\n");
+		return NULL;
+	}
+
+	return &dn->fwnode;
+}
+
 /**
  * __acpi_node_get_property_reference - returns handle to the referenced object
  * @fwnode: Firmware node to get the property from
@@ -887,6 +916,7 @@ int __acpi_node_get_property_reference(c
 	const union acpi_object *element, *end;
 	const union acpi_object *obj;
 	const struct acpi_device_data *data;
+	struct fwnode_handle *ref_fwnode;
 	struct acpi_device *device;
 	int ret, idx = 0;
 
@@ -910,16 +940,30 @@ int __acpi_node_get_property_reference(c
 
 		args->fwnode = acpi_fwnode_handle(device);
 		args->nargs = 0;
+
+		return 0;
+	case ACPI_TYPE_STRING:
+		if (index)
+			return -ENOENT;
+
+		ref_fwnode = acpi_parse_string_ref(fwnode, obj->string.pointer);
+		if (!ref_fwnode)
+			return -EINVAL;
+
+		args->fwnode = ref_fwnode;
+		args->nargs = 0;
+
 		return 0;
 	case ACPI_TYPE_PACKAGE:
 		/*
 		 * If it is not a single reference, then it is a package of
-		 * references followed by number of ints as follows:
+		 * references, followed by number of ints as follows:
 		 *
 		 *  Package () { REF, INT, REF, INT, INT }
 		 *
-		 * The index argument is then used to determine which reference
-		 * the caller wants (along with the arguments).
+		 * Here, REF may be either a local reference or a string. The
+		 * index argument is then used to determine which reference the
+		 * caller wants (along with the arguments).
 		 */
 		break;
 	default:
@@ -947,6 +991,24 @@ int __acpi_node_get_property_reference(c
 			if (ret < 0)
 				return ret;
 
+			if (idx == index)
+				return 0;
+
+			break;
+		case ACPI_TYPE_STRING:
+			ref_fwnode = acpi_parse_string_ref(fwnode,
+							   element->string.pointer);
+			if (!ref_fwnode)
+				return -EINVAL;
+
+			element++;
+
+			ret = acpi_get_ref_args(idx == index ? args : NULL,
+						ref_fwnode, &element, end,
+						num_args);
+			if (ret < 0)
+				return ret;
+
 			if (idx == index)
 				return 0;
 

[PATCH v2 2/6] ACPI: scan: Extract CSI-2 connection graph from _CRS

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Find ACPI CSI-2 resource descriptors defined since ACPI 6.4 (for
CSI-2 and camera configuration) in _CRS for all device objects in
the given scope of the ACPI namespace that have them, identify the
corresponding "remote endpoint" device objects for them and
allocate memory for software nodes needed to create a DT-like data
structure representing the CSI-2 connection graph for drivers.

The code needed to populate these software nodes will be added by
subsequent change sets.

Link: https://uefi.org/specs/ACPI/6.5/06_Device_Configuration.html#camera-serial-interface-csi-2-connection-resource-descriptor
Co-developed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/acpi/Makefile   |    2 
 drivers/acpi/internal.h |    8 +
 drivers/acpi/mipi-di.c  |  295 ++++++++++++++++++++++++++++++++++++++++++++++++
 drivers/acpi/scan.c     |   48 ++++++-
 include/acpi/acpi_bus.h |   18 ++
 5 files changed, 361 insertions(+), 10 deletions(-)
 create mode 100644 drivers/acpi/mipi-di.c

Index: linux-pm/drivers/acpi/Makefile
===================================================================
--- linux-pm.orig/drivers/acpi/Makefile
+++ linux-pm/drivers/acpi/Makefile
@@ -37,7 +37,7 @@ acpi-$(CONFIG_ACPI_SLEEP)	+= proc.o
 # ACPI Bus and Device Drivers
 #
 acpi-y				+= bus.o glue.o
-acpi-y				+= scan.o
+acpi-y				+= scan.o mipi-di.o
 acpi-y				+= resource.o
 acpi-y				+= acpi_processor.o
 acpi-y				+= processor_core.o
Index: linux-pm/drivers/acpi/internal.h
===================================================================
--- linux-pm.orig/drivers/acpi/internal.h
+++ linux-pm/drivers/acpi/internal.h
@@ -281,4 +281,12 @@ void acpi_init_lpit(void);
 static inline void acpi_init_lpit(void) { }
 #endif
 
+/*--------------------------------------------------------------------------
+		ACPI _CRS CSI-2 and MIPI DisCo for Imaging
+  -------------------------------------------------------------------------- */
+
+void acpi_mipi_check_crs_csi2(acpi_handle handle);
+void acpi_mipi_scan_crs_csi2(void);
+void acpi_mipi_crs_csi2_cleanup(void);
+
 #endif /* _ACPI_INTERNAL_H_ */
Index: linux-pm/drivers/acpi/mipi-di.c
===================================================================
--- /dev/null
+++ linux-pm/drivers/acpi/mipi-di.c
@@ -0,0 +1,295 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * MIPI DisCo for Imaging support.
+ *
+ * Copyright (C) 2023 Intel Corporation
+ *
+ * Support MIPI DisCo for Imaging by parsing ACPI _CRS CSI-2 records defined in
+ * Section 6.4.3.8.2.4 "Camera Serial Interface (CSI-2) Connection Resource
+ * Descriptor" of ACPI 6.5.
+ *
+ * The implementation looks for the information in the ACPI namespace (CSI-2
+ * resource descriptors in _CRS) and constructs software nodes compatible with
+ * Documentation/firmware-guide/acpi/dsd/graph.rst to represent the CSI-2
+ * connection graph.
+ */
+
+#include <linux/acpi.h>
+#include <linux/limits.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/overflow.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+#include "internal.h"
+
+static LIST_HEAD(acpi_mipi_crs_csi2_list);
+
+static void acpi_mipi_data_tag(acpi_handle handle, void *context)
+{
+}
+
+/* Connection data extracted from one _CRS CSI-2 resource descriptor. */
+struct crs_csi2_connection {
+	struct list_head entry;
+	struct acpi_resource_csi2_serialbus csi2_data;
+	acpi_handle remote_handle;
+	char remote_name[];
+};
+
+/* Data extracted from _CRS CSI-2 resource descriptors for one device. */
+struct crs_csi2 {
+	struct list_head entry;
+	acpi_handle handle;
+	struct acpi_device_software_nodes *swnodes;
+	struct list_head connections;
+	u32 port_count;
+};
+
+struct csi2_resources_walk_data {
+	acpi_handle handle;
+	struct list_head connections;
+};
+
+static acpi_status parse_csi2_resource(struct acpi_resource *res, void *context)
+{
+	struct csi2_resources_walk_data *crwd = context;
+	struct acpi_resource_csi2_serialbus *csi2_res;
+	struct acpi_resource_source *csi2_res_src;
+	u16 csi2_res_src_length;
+	struct crs_csi2_connection *conn;
+	acpi_handle remote_handle;
+
+	if (res->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
+		return AE_OK;
+
+	csi2_res = &res->data.csi2_serial_bus;
+
+	if (csi2_res->type != ACPI_RESOURCE_SERIAL_TYPE_CSI2)
+		return AE_OK;
+
+	csi2_res_src = &csi2_res->resource_source;
+	if (ACPI_FAILURE(acpi_get_handle(NULL, csi2_res_src->string_ptr,
+					 &remote_handle))) {
+		acpi_handle_debug(crwd->handle,
+				  "unable to find resource source\n");
+		return AE_OK;
+	}
+	csi2_res_src_length = csi2_res_src->string_length;
+	if (!csi2_res_src_length) {
+		acpi_handle_debug(crwd->handle,
+				  "invalid resource source string length\n");
+		return AE_OK;
+	}
+
+	conn = kmalloc(struct_size(conn, remote_name, csi2_res_src_length + 1),
+		       GFP_KERNEL);
+	if (!conn)
+		return AE_OK;
+
+	conn->csi2_data = *csi2_res;
+	strscpy(conn->remote_name, csi2_res_src->string_ptr, csi2_res_src_length);
+	conn->csi2_data.resource_source.string_ptr = conn->remote_name;
+	conn->remote_handle = remote_handle;
+
+	list_add(&conn->entry, &crwd->connections);
+
+	return AE_OK;
+}
+
+static struct crs_csi2 *acpi_mipi_add_crs_csi2(acpi_handle handle,
+					       struct list_head *list)
+{
+	struct crs_csi2 *csi2;
+
+	csi2 = kzalloc(sizeof(*csi2), GFP_KERNEL);
+	if (!csi2)
+		return NULL;
+
+	csi2->handle = handle;
+	INIT_LIST_HEAD(&csi2->connections);
+	csi2->port_count = 1;
+
+	if (ACPI_FAILURE(acpi_attach_data(handle, acpi_mipi_data_tag, csi2))) {
+		kfree(csi2);
+		return NULL;
+	}
+
+	list_add(&csi2->entry, list);
+
+	return csi2;
+}
+
+static struct crs_csi2 *acpi_mipi_get_crs_csi2(acpi_handle handle)
+{
+	struct crs_csi2 *csi2;
+
+	if (ACPI_FAILURE(acpi_get_data_full(handle, acpi_mipi_data_tag,
+					    (void **)&csi2, NULL)))
+		return NULL;
+
+	return csi2;
+}
+
+static void csi_csr2_release_connections(struct list_head *list)
+{
+	struct crs_csi2_connection *conn, *conn_tmp;
+
+	list_for_each_entry_safe(conn, conn_tmp, list, entry) {
+		list_del(&conn->entry);
+		kfree(conn);
+	}
+}
+
+static void acpi_mipi_del_crs_csi2(struct crs_csi2 *csi2)
+{
+	list_del(&csi2->entry);
+	acpi_detach_data(csi2->handle, acpi_mipi_data_tag);
+	kfree(csi2->swnodes);
+	csi_csr2_release_connections(&csi2->connections);
+	kfree(csi2);
+}
+
+/**
+ * acpi_mipi_check_crs_csi2 - Look for devices with _CRS CSI-2 resources
+ * @handle: ACPI namespace walk starting point.
+ *
+ * Find all devices with _CRS CSI-2 resource descriptors in the ACPI namespace
+ * branch starting at @handle and collect them into a list.
+ */
+void acpi_mipi_check_crs_csi2(acpi_handle handle)
+{
+	struct csi2_resources_walk_data crwd = {
+		.handle = handle,
+		.connections = LIST_HEAD_INIT(crwd.connections),
+	};
+	struct crs_csi2 *csi2;
+
+	/*
+	 * Avoid allocating _CRS CSI-2 objects for devices without any CSI-2
+	 * resource descriptions in _CRS to reduce overhead.
+	 */
+	acpi_walk_resources(handle, METHOD_NAME__CRS, parse_csi2_resource, &crwd);
+	if (list_empty(&crwd.connections))
+		return;
+
+	/*
+	 * Create a _CRS CSI-2 entry to store the extracted connection
+	 * information and add it to the global list.
+	 */
+	csi2 = acpi_mipi_add_crs_csi2(handle, &acpi_mipi_crs_csi2_list);
+	if (!csi2) {
+		csi_csr2_release_connections(&crwd.connections);
+		return; /* Nothing really can be done about this. */
+	}
+
+	list_replace(&crwd.connections, &csi2->connections);
+}
+
+#define NO_CSI2_PORT (UINT_MAX - 1)
+
+static void alloc_crs_csi2_swnodes(struct crs_csi2 *csi2)
+{
+	size_t port_count = csi2->port_count;
+	struct acpi_device_software_nodes *swnodes;
+	size_t alloc_size;
+	unsigned int i;
+
+	/*
+	 * Allocate memory for ports, node pointers (number of nodes +
+	 * 1 (guardian), nodes (root + number of ports * 2 (because for
+	 * every port there is an endpoint)).
+	 */
+	if (check_mul_overflow(sizeof(*swnodes->ports) +
+			       sizeof(*swnodes->nodes) * 2 +
+			       sizeof(*swnodes->nodeptrs) * 2,
+			       port_count, &alloc_size))
+		goto overflow;
+
+	if (check_add_overflow(sizeof(*swnodes) +
+			       sizeof(*swnodes->nodes) +
+			       sizeof(*swnodes->nodeptrs) * 2,
+			       alloc_size, &alloc_size))
+		goto overflow;
+
+	swnodes = kmalloc(alloc_size, GFP_KERNEL);
+	if (!swnodes)
+		return;
+
+	swnodes->ports = (struct acpi_device_software_node_port *)(swnodes + 1);
+	swnodes->nodes = (struct software_node *)(swnodes->ports + port_count);
+	swnodes->nodeptrs = (const struct software_node **)(swnodes->nodes + 1 +
+				2 * port_count);
+	swnodes->num_ports = port_count;
+
+	for (i = 0; i < 2 * port_count + 1; i++)
+		swnodes->nodeptrs[i] = &swnodes->nodes[i];
+
+	swnodes->nodeptrs[i] = NULL;
+
+	for (i = 0; i < port_count; i++)
+		swnodes->ports[i].port_nr = NO_CSI2_PORT;
+
+	csi2->swnodes = swnodes;
+	return;
+
+overflow:
+	acpi_handle_info(csi2->handle, "too many _CRS CSI-2 resource handles (%zu)",
+			 port_count);
+}
+
+/**
+ * acpi_mipi_scan_crs_csi2 - Create ACPI _CRS CSI-2 software nodes
+ *
+ * Note that this function must be called before any struct acpi_device objects
+ * are bound to any ACPI drivers or scan handlers, so it cannot assume the
+ * existence of struct acpi_device objects for every device present in the ACPI
+ * namespace.
+ *
+ * acpi_scan_lock in scan.c must be held when calling this function.
+ */
+void acpi_mipi_scan_crs_csi2(void)
+{
+	struct crs_csi2 *csi2;
+	LIST_HEAD(aux_list);
+
+	/* Count references to each ACPI handle in the CSI-2 connection graph. */
+	list_for_each_entry(csi2, &acpi_mipi_crs_csi2_list, entry) {
+		struct crs_csi2_connection *conn;
+
+		list_for_each_entry(conn, &csi2->connections, entry) {
+			struct crs_csi2 *remote_csi2;
+
+			csi2->port_count++;
+
+			remote_csi2 = acpi_mipi_get_crs_csi2(conn->remote_handle);
+			if (remote_csi2) {
+				remote_csi2->port_count++;
+				continue;
+			}
+			/*
+			 * The remote endpoint has no _CRS CSI-2 list entry yet,
+			 * so create one for it and add it to the list.
+			 */
+			acpi_mipi_add_crs_csi2(conn->remote_handle, &aux_list);
+		}
+	}
+	list_splice(&aux_list, &acpi_mipi_crs_csi2_list);
+
+	/* Allocate softwware nodes for representing the CSI-2 information. */
+	list_for_each_entry(csi2, &acpi_mipi_crs_csi2_list, entry)
+		alloc_crs_csi2_swnodes(csi2);
+}
+
+/**
+ * acpi_mipi_crs_csi2_cleanup - Free _CRS CSI-2 temporary data
+ */
+void acpi_mipi_crs_csi2_cleanup(void)
+{
+	struct crs_csi2 *csi2, *csi2_tmp;
+
+	list_for_each_entry_safe(csi2, csi2_tmp, &acpi_mipi_crs_csi2_list, entry)
+		acpi_mipi_del_crs_csi2(csi2);
+}
Index: linux-pm/include/acpi/acpi_bus.h
===================================================================
--- linux-pm.orig/include/acpi/acpi_bus.h
+++ linux-pm/include/acpi/acpi_bus.h
@@ -366,6 +366,24 @@ struct acpi_device_data {
 
 struct acpi_gpio_mapping;
 
+struct acpi_device_software_node_port {
+	unsigned int port_nr;
+};
+
+/**
+ * struct acpi_device_software_nodes - Software nodes for an ACPI device
+ * @nodes: Software nodes for root as well as ports and endpoints.
+ * @nodeprts: Array of software node pointers, for (un)registering them.
+ * @ports: Information related to each port and endpoint within a port.
+ * @num_ports: The number of ports.
+ */
+struct acpi_device_software_nodes {
+	struct software_node *nodes;
+	const struct software_node **nodeptrs;
+	struct acpi_device_software_node_port *ports;
+	unsigned int num_ports;
+};
+
 /* Device */
 struct acpi_device {
 	u32 pld_crc;
Index: linux-pm/drivers/acpi/scan.c
===================================================================
--- linux-pm.orig/drivers/acpi/scan.c
+++ linux-pm/drivers/acpi/scan.c
@@ -1976,7 +1976,7 @@ static void acpi_scan_init_hotplug(struc
 	}
 }
 
-static u32 acpi_scan_check_dep(acpi_handle handle, bool check_dep)
+static u32 acpi_scan_check_dep(acpi_handle handle)
 {
 	struct acpi_handle_list dep_devices;
 	acpi_status status;
@@ -1989,8 +1989,7 @@ static u32 acpi_scan_check_dep(acpi_hand
 	 * 2. ACPI nodes describing USB ports.
 	 * Still, checking for _HID catches more then just these cases ...
 	 */
-	if (!check_dep || !acpi_has_method(handle, "_DEP") ||
-	    !acpi_has_method(handle, "_HID"))
+	if (!acpi_has_method(handle, "_DEP") || !acpi_has_method(handle, "_HID"))
 		return 0;
 
 	status = acpi_evaluate_reference(handle, "_DEP", NULL, &dep_devices);
@@ -2036,7 +2035,13 @@ static u32 acpi_scan_check_dep(acpi_hand
 	return count;
 }
 
-static acpi_status acpi_bus_check_add(acpi_handle handle, bool check_dep,
+static acpi_status acpi_scan_check_crs_csi2_cb(acpi_handle handle, u32 a, void *b, void **c)
+{
+	acpi_mipi_check_crs_csi2(handle);
+	return AE_OK;
+}
+
+static acpi_status acpi_bus_check_add(acpi_handle handle, bool first_pass,
 				      struct acpi_device **adev_p)
 {
 	struct acpi_device *device = acpi_fetch_acpi_dev(handle);
@@ -2054,9 +2059,25 @@ static acpi_status acpi_bus_check_add(ac
 		if (acpi_device_should_be_hidden(handle))
 			return AE_OK;
 
-		/* Bail out if there are dependencies. */
-		if (acpi_scan_check_dep(handle, check_dep) > 0)
-			return AE_CTRL_DEPTH;
+		if (first_pass) {
+			acpi_mipi_check_crs_csi2(handle);
+
+			/* Bail out if there are dependencies. */
+			if (acpi_scan_check_dep(handle) > 0) {
+				/*
+				 * The entire CSI-2 connection graph needs to be
+				 * extracted before any drivers or scan handlers
+				 * are bound to struct device objects, so scan
+				 * _CRS CSI-2 resource descriptors for all
+				 * devices below the current handle.
+				 */
+				acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
+						    ACPI_UINT32_MAX,
+						    acpi_scan_check_crs_csi2_cb,
+						    NULL, NULL, NULL);
+				return AE_CTRL_DEPTH;
+			}
+		}
 
 		fallthrough;
 	case ACPI_TYPE_ANY:	/* for ACPI_ROOT_OBJECT */
@@ -2079,10 +2100,10 @@ static acpi_status acpi_bus_check_add(ac
 	}
 
 	/*
-	 * If check_dep is true at this point, the device has no dependencies,
+	 * If first_pass is true at this point, the device has no dependencies,
 	 * or the creation of the device object would have been postponed above.
 	 */
-	acpi_add_single_object(&device, handle, type, !check_dep);
+	acpi_add_single_object(&device, handle, type, !first_pass);
 	if (!device)
 		return AE_CTRL_DEPTH;
 
@@ -2494,12 +2515,21 @@ int acpi_bus_scan(acpi_handle handle)
 	if (!device)
 		return -ENODEV;
 
+	/*
+	 * Allocate ACPI _CRS CSI-2 software nodes using information extracted
+	 * from the _CRS CSI-2 resource descriptors during the ACPI namespace
+	 * walk above.
+	 */
+	acpi_mipi_scan_crs_csi2();
+
 	acpi_bus_attach(device, (void *)true);
 
 	/* Pass 2: Enumerate all of the remaining devices. */
 
 	acpi_scan_postponed();
 
+	acpi_mipi_crs_csi2_cleanup();
+
 	return 0;
 }
 EXPORT_SYMBOL(acpi_bus_scan);

[PATCH v2 3/6] ACPI: scan: Extract _CRS CSI-2 connection information into swnodes

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Use the connection information extracted from the _CRS CSI-2 resource
descriptors for all devices that have them to populate port names and the
"reg", "bus-type" and "remote-endpoint" properties in the software nodes
representing the CSI-2 connection graph.

Link: https://uefi.org/specs/ACPI/6.5/06_Device_Configuration.html#camera-serial-interface-csi-2-connection-resource-descriptor
Co-developed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/acpi/mipi-di.c  |  153 +++++++++++++++++++++++++++++++++++++++++++++++-
 include/acpi/acpi_bus.h |   53 ++++++++++++++++
 2 files changed, 205 insertions(+), 1 deletion(-)

Index: linux-pm/include/acpi/acpi_bus.h
===================================================================
--- linux-pm.orig/include/acpi/acpi_bus.h
+++ linux-pm/include/acpi/acpi_bus.h
@@ -366,8 +366,61 @@ struct acpi_device_data {
 
 struct acpi_gpio_mapping;
 
+#define ACPI_DEVICE_CSI2_DATA_LANES		4
+
+#define ACPI_DEVICE_SWNODE_PORT_NAME_LENGTH	8
+
+enum acpi_device_swnode_port_props {
+	ACPI_DEVICE_SWNODE_PORT_REG,
+	ACPI_DEVICE_SWNODE_PORT_NUM_OF,
+	ACPI_DEVICE_SWNODE_PORT_NUM_ENTRIES
+};
+
+enum acpi_device_swnode_ep_props {
+	ACPI_DEVICE_SWNODE_EP_REMOTE_EP,
+	ACPI_DEVICE_SWNODE_EP_BUS_TYPE,
+	ACPI_DEVICE_SWNODE_EP_REG,
+	ACPI_DEVICE_SWNODE_EP_CLOCK_LANES,
+	ACPI_DEVICE_SWNODE_EP_DATA_LANES,
+	ACPI_DEVICE_SWNODE_EP_LANE_POLARITIES,
+	/* TX only */
+	ACPI_DEVICE_SWNODE_EP_LINK_FREQUENCIES,
+	ACPI_DEVICE_SWNODE_EP_NUM_OF,
+	ACPI_DEVICE_SWNODE_EP_NUM_ENTRIES
+};
+
+/*
+ * Each device has a root software node plus two times as many nodes as the
+ * number of CSI-2 ports.
+ */
+#define ACPI_DEVICE_SWNODE_PORT(port)	(2 * (port) + 1)
+#define ACPI_DEVICE_SWNODE_EP(endpoint)	\
+		(ACPI_DEVICE_SWNODE_PORT(endpoint) + 1)
+
+/**
+ * struct acpi_device_software_node_port - MIPI DisCo for Imaging CSI-2 port
+ * @port_name: Port name.
+ * @data_lanes: "data-lanes" property values.
+ * @lane_polarities: "lane-polarities" property values.
+ * @link_frequencies: "link_frequencies" property values.
+ * @port_nr: Port number.
+ * @crs_crs2_local: _CRS CSI2 record present (i.e. this is a transmitter one).
+ * @port_props: Port properties.
+ * @ep_props: Endpoint properties.
+ * @remote_ep: Reference to the remote endpoint.
+ */
 struct acpi_device_software_node_port {
+	char port_name[ACPI_DEVICE_SWNODE_PORT_NAME_LENGTH + 1];
+	u32 data_lanes[ACPI_DEVICE_CSI2_DATA_LANES];
+	u32 lane_polarities[ACPI_DEVICE_CSI2_DATA_LANES + 1 /* clock lane */];
+	u64 link_frequencies[ACPI_DEVICE_CSI2_DATA_LANES];
 	unsigned int port_nr;
+	bool crs_csi2_local;
+
+	struct property_entry port_props[ACPI_DEVICE_SWNODE_PORT_NUM_ENTRIES];
+	struct property_entry ep_props[ACPI_DEVICE_SWNODE_EP_NUM_ENTRIES];
+
+	struct software_node_ref_args remote_ep[1];
 };
 
 /**
Index: linux-pm/drivers/acpi/mipi-di.c
===================================================================
--- linux-pm.orig/drivers/acpi/mipi-di.c
+++ linux-pm/drivers/acpi/mipi-di.c
@@ -23,6 +23,8 @@
 #include <linux/slab.h>
 #include <linux/string.h>
 
+#include <media/v4l2-fwnode.h>
+
 #include "internal.h"
 
 static LIST_HEAD(acpi_mipi_crs_csi2_list);
@@ -240,6 +242,142 @@ overflow:
 			 port_count);
 }
 
+#define ACPI_CRS_CSI2_PHY_TYPE_C	0
+#define ACPI_CRS_CSI2_PHY_TYPE_D	1
+
+static unsigned int next_csi2_port_index(struct acpi_device_software_nodes *swnodes,
+					 unsigned int port_nr)
+{
+	unsigned int i;
+
+	for (i = 0; i < swnodes->num_ports; i++) {
+		struct acpi_device_software_node_port *port = &swnodes->ports[i];
+
+		if (port->port_nr == port_nr)
+			return i;
+
+		if (port->port_nr == NO_CSI2_PORT) {
+			port->port_nr = port_nr;
+			return i;
+		}
+	}
+
+	return NO_CSI2_PORT;
+}
+
+/* Print graph port name into a buffer, return non-zero on failure. */
+#define GRAPH_PORT_NAME(var, num)					    \
+	(snprintf((var), sizeof(var), SWNODE_GRAPH_PORT_NAME_FMT, (num)) >= \
+	 sizeof(var))
+
+static void extract_crs_csi2_conn_info(acpi_handle local_handle,
+				       struct acpi_device_software_nodes *local_swnodes,
+				       struct crs_csi2_connection *conn)
+{
+	struct crs_csi2 *remote_csi2 = acpi_mipi_get_crs_csi2(conn->remote_handle);
+	struct acpi_device_software_nodes *remote_swnodes;
+	struct acpi_device_software_node_port *local_port, *remote_port;
+	struct software_node *local_node, *remote_node;
+	unsigned int local_index, remote_index;
+	unsigned int bus_type;
+
+	/*
+	 * If the previous steps have failed to make room for a _CRS CSI-2
+	 * representation for the remote end of the given connection, skip it.
+	 */
+	if (!remote_csi2)
+		return;
+
+	remote_swnodes = remote_csi2->swnodes;
+	if (!remote_swnodes)
+		return;
+
+	switch (conn->csi2_data.phy_type) {
+	case ACPI_CRS_CSI2_PHY_TYPE_C:
+		bus_type = V4L2_FWNODE_BUS_TYPE_CSI2_CPHY;
+		break;
+
+	case ACPI_CRS_CSI2_PHY_TYPE_D:
+		bus_type = V4L2_FWNODE_BUS_TYPE_CSI2_DPHY;
+		break;
+
+	default:
+		acpi_handle_info(local_handle, "unknown CSI-2 PHY type %u\n",
+				 conn->csi2_data.phy_type);
+		return;
+	}
+
+	local_index = next_csi2_port_index(local_swnodes,
+					   conn->csi2_data.local_port_instance);
+	if (WARN_ON_ONCE(local_index >= local_swnodes->num_ports))
+		return;
+
+	remote_index = next_csi2_port_index(remote_swnodes,
+					    conn->csi2_data.resource_source.index);
+	if (WARN_ON_ONCE(remote_index >= remote_swnodes->num_ports))
+		return;
+
+	local_port = &local_swnodes->ports[local_index];
+	local_node = &local_swnodes->nodes[ACPI_DEVICE_SWNODE_EP(local_index)];
+	local_port->crs_csi2_local = true;
+
+	remote_port = &remote_swnodes->ports[remote_index];
+	remote_node = &remote_swnodes->nodes[ACPI_DEVICE_SWNODE_EP(remote_index)];
+
+	local_port->remote_ep[0] = SOFTWARE_NODE_REFERENCE(remote_node);
+	remote_port->remote_ep[0] = SOFTWARE_NODE_REFERENCE(local_node);
+
+	local_port->ep_props[ACPI_DEVICE_SWNODE_EP_REMOTE_EP] =
+			PROPERTY_ENTRY_REF_ARRAY("remote-endpoint",
+						 local_port->remote_ep);
+
+	local_port->ep_props[ACPI_DEVICE_SWNODE_EP_BUS_TYPE] =
+			PROPERTY_ENTRY_U32("bus-type", bus_type);
+
+	local_port->ep_props[ACPI_DEVICE_SWNODE_EP_REG] =
+			PROPERTY_ENTRY_U32("reg", 0);
+
+	local_port->port_props[ACPI_DEVICE_SWNODE_PORT_REG] =
+			PROPERTY_ENTRY_U32("reg", conn->csi2_data.local_port_instance);
+
+	if (GRAPH_PORT_NAME(local_port->port_name,
+			    conn->csi2_data.local_port_instance))
+		acpi_handle_info(local_handle, "local port %u name too long",
+				 conn->csi2_data.local_port_instance);
+
+	remote_port->ep_props[ACPI_DEVICE_SWNODE_EP_REMOTE_EP] =
+			PROPERTY_ENTRY_REF_ARRAY("remote-endpoint",
+						 remote_port->remote_ep);
+
+	remote_port->ep_props[ACPI_DEVICE_SWNODE_EP_BUS_TYPE] =
+			PROPERTY_ENTRY_U32("bus-type", bus_type);
+
+	remote_port->ep_props[ACPI_DEVICE_SWNODE_EP_REG] =
+			PROPERTY_ENTRY_U32("reg", 0);
+
+	remote_port->port_props[ACPI_DEVICE_SWNODE_PORT_REG] =
+			PROPERTY_ENTRY_U32("reg", conn->csi2_data.resource_source.index);
+
+	if (GRAPH_PORT_NAME(remote_port->port_name,
+			    conn->csi2_data.resource_source.index))
+		acpi_handle_info(local_handle, "remote port %u name too long",
+				 conn->csi2_data.resource_source.index);
+}
+
+static void prepare_crs_csi2_swnodes(struct crs_csi2 *csi2)
+{
+	struct acpi_device_software_nodes *local_swnodes = csi2->swnodes;
+	acpi_handle local_handle = csi2->handle;
+	struct crs_csi2_connection *conn;
+
+	/* Bail out if the allocation of swnodes has failed. */
+	if (!local_swnodes)
+		return;
+
+	list_for_each_entry(conn, &csi2->connections, entry)
+		extract_crs_csi2_conn_info(local_handle, local_swnodes, conn);
+}
+
 /**
  * acpi_mipi_scan_crs_csi2 - Create ACPI _CRS CSI-2 software nodes
  *
@@ -278,9 +416,22 @@ void acpi_mipi_scan_crs_csi2(void)
 	}
 	list_splice(&aux_list, &acpi_mipi_crs_csi2_list);
 
-	/* Allocate softwware nodes for representing the CSI-2 information. */
+	/*
+	 * Allocate softwware nodes for representing the CSI-2 information.
+	 *
+	 * This needs to be done for all of the list entries in one go, because
+	 * they may point to each other without restrictions and the next step
+	 * relies on the availability of swnodes memory for each list entry.
+	 */
 	list_for_each_entry(csi2, &acpi_mipi_crs_csi2_list, entry)
 		alloc_crs_csi2_swnodes(csi2);
+
+	/*
+	 * Set up software node properties using data from _CRS CSI-2 resource
+	 * descriptors.
+	 */
+	list_for_each_entry(csi2, &acpi_mipi_crs_csi2_list, entry)
+		prepare_crs_csi2_swnodes(csi2);
 }
 
 /**

[PATCH v2 4/6] device property: Add SOFTWARE_NODE() macro for defining software nodes

[Rafael J. Wysocki]

From: Sakari Ailus <sakari.ailus@linux.intel.com>

Add SOFTWARE_NODE() macro in order to make defining software nodes look
nicer. This is analogous to different PROPERTY_ENTRY_*() macros for
defining properties.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
---
 include/linux/property.h |    7 +++++++
 1 file changed, 7 insertions(+)

Index: linux-pm/include/linux/property.h
===================================================================
--- linux-pm.orig/include/linux/property.h
+++ linux-pm/include/linux/property.h
@@ -488,6 +488,13 @@ struct software_node {
 	const struct property_entry *properties;
 };
 
+#define SOFTWARE_NODE(_name_, _properties_, _parent_)	\
+	(struct software_node) {			\
+		.name = _name_,				\
+		.properties = _properties_,		\
+		.parent = _parent_,			\
+	}
+
 bool is_software_node(const struct fwnode_handle *fwnode);
 const struct software_node *
 to_software_node(const struct fwnode_handle *fwnode);

[PATCH v2 5/6] ACPI: scan: Extract MIPI DiSco for Imaging data into swnodes

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Add information extracted from the MIPI DiSco for Imaging device
properties to software nodes created during the CSI-2 connection graph
discovery.

Link: https://www.mipi.org/specifications/mipi-di
Co-developed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/acpi/internal.h |    1 
 drivers/acpi/mipi-di.c  |  240 +++++++++++++++++++++++++++++++++++++++++++++++-
 drivers/acpi/scan.c     |   12 ++
 include/acpi/acpi_bus.h |   10 ++
 4 files changed, 259 insertions(+), 4 deletions(-)

Index: linux-pm/drivers/acpi/mipi-di.c
===================================================================
--- linux-pm.orig/drivers/acpi/mipi-di.c
+++ linux-pm/drivers/acpi/mipi-di.c
@@ -6,12 +6,16 @@
  *
  * Support MIPI DisCo for Imaging by parsing ACPI _CRS CSI-2 records defined in
  * Section 6.4.3.8.2.4 "Camera Serial Interface (CSI-2) Connection Resource
- * Descriptor" of ACPI 6.5.
+ * Descriptor" of ACPI 6.5 and using device properties defined by the MIPI DisCo
+ * for Imaging specification.
  *
  * The implementation looks for the information in the ACPI namespace (CSI-2
  * resource descriptors in _CRS) and constructs software nodes compatible with
  * Documentation/firmware-guide/acpi/dsd/graph.rst to represent the CSI-2
- * connection graph.
+ * connection graph.  The software nodes are then populated with the data
+ * extracted from the _CRS CSI-2 resource descriptors and the MIPI DisCo
+ * for Imaging device properties present in _DSD for the ACPI device objects
+ * with CSI-2 connections.
  */
 
 #include <linux/acpi.h>
@@ -434,6 +438,238 @@ void acpi_mipi_scan_crs_csi2(void)
 		prepare_crs_csi2_swnodes(csi2);
 }
 
+/*
+ * Get the index of the next property in the property array, with a given
+ * maximum value.
+ */
+#define NEXT_PROPERTY(index, max)			\
+	(WARN_ON((index) > ACPI_DEVICE_SWNODE_##max) ?	\
+	 ACPI_DEVICE_SWNODE_##max : (index)++)
+
+static void init_csi2_port_local(struct acpi_device *adev,
+				 struct acpi_device_software_node_port *port,
+				 struct fwnode_handle *port_fwnode,
+				 unsigned int index)
+{
+	acpi_handle handle = acpi_device_handle(adev);
+	unsigned int num_link_freqs;
+	int ret;
+
+	ret = fwnode_property_count_u64(port_fwnode, "mipi-img-link-frequencies");
+	if (ret <= 0)
+		return;
+
+	num_link_freqs = ret;
+	if (num_link_freqs > ARRAY_SIZE(port->link_frequencies)) {
+		acpi_handle_info(handle, "Too many link frequencies: %u\n",
+				 num_link_freqs);
+		num_link_freqs = ARRAY_SIZE(port->link_frequencies);
+	}
+
+	ret = fwnode_property_read_u64_array(port_fwnode,
+					     "mipi-img-link-frequencies",
+					     port->link_frequencies,
+					     num_link_freqs);
+	if (ret) {
+		acpi_handle_info(handle, "Unable to get link frequencies (%d)\n",
+				 ret);
+		return;
+	}
+
+	port->ep_props[NEXT_PROPERTY(index, EP_LINK_FREQUENCIES)] =
+				PROPERTY_ENTRY_U64_ARRAY_LEN("link-frequencies",
+							     port->link_frequencies,
+							     num_link_freqs);
+}
+
+static void init_csi2_port(struct acpi_device *adev,
+			   struct acpi_device_software_nodes *swnodes,
+			   struct acpi_device_software_node_port *port,
+			   struct fwnode_handle *port_fwnode,
+			   unsigned int port_index)
+{
+	unsigned int ep_prop_index = ACPI_DEVICE_SWNODE_EP_CLOCK_LANES;
+	acpi_handle handle = acpi_device_handle(adev);
+	u8 val[ARRAY_SIZE(port->data_lanes)];
+	unsigned int num_lanes = 0;
+	int ret;
+
+	if (GRAPH_PORT_NAME(port->port_name, port->port_nr))
+		return;
+
+	swnodes->nodes[ACPI_DEVICE_SWNODE_PORT(port_index)] =
+			SOFTWARE_NODE(port->port_name, port->port_props,
+				      &swnodes->nodes[ACPI_DEVICE_SWNODE_ROOT]);
+
+	ret = fwnode_property_read_u8(port_fwnode, "mipi-img-clock-lane", val);
+	if (!ret)
+		port->ep_props[NEXT_PROPERTY(ep_prop_index, EP_CLOCK_LANES)] =
+			PROPERTY_ENTRY_U32("clock-lanes", val[0]);
+
+	ret = fwnode_property_count_u8(port_fwnode, "mipi-img-data-lanes");
+	if (ret > 0) {
+		num_lanes = ret;
+
+		if (num_lanes > ARRAY_SIZE(port->data_lanes)) {
+			acpi_handle_info(handle, "Too many data lanes: %u\n",
+					 num_lanes);
+			num_lanes = ARRAY_SIZE(port->data_lanes);
+		}
+
+		ret = fwnode_property_read_u8_array(port_fwnode,
+						    "mipi-img-data-lanes",
+						    val, num_lanes);
+		if (!ret) {
+			unsigned int i;
+
+			for (i = 0; i < num_lanes; i++)
+				port->data_lanes[i] = val[i];
+
+			port->ep_props[NEXT_PROPERTY(ep_prop_index, EP_DATA_LANES)] =
+				PROPERTY_ENTRY_U32_ARRAY_LEN("data-lanes",
+							     port->data_lanes,
+							     num_lanes);
+		}
+	}
+
+	ret = fwnode_property_count_u8(port_fwnode, "mipi-img-lane-polarities");
+	if (ret > 0) {
+		unsigned long mask;
+		unsigned int i;
+
+		/*
+		 * Total number of lanes here is clock lane + data lanes.
+		 * Require that number to be low enough so they all can be
+		 * covered by the bits in one byte.
+		 */
+		BUILD_BUG_ON(BITS_PER_TYPE(u8) <= ARRAY_SIZE(port->data_lanes));
+
+		fwnode_property_read_u8_array(port_fwnode,
+					      "mipi-img-lane-polarities",
+					      val, 1);
+
+		for (mask = val[0], i = 0; i < num_lanes + 1; i++)
+			port->lane_polarities[i] = test_bit(i, &mask);
+
+		port->ep_props[NEXT_PROPERTY(ep_prop_index, EP_LANE_POLARITIES)] =
+				PROPERTY_ENTRY_U32_ARRAY_LEN("lane-polarities",
+							     port->lane_polarities,
+							     1 + num_lanes);
+	} else {
+		acpi_handle_info(handle, "No lane polarity bytes\n");
+	}
+
+	swnodes->nodes[ACPI_DEVICE_SWNODE_EP(port_index)] =
+		SOFTWARE_NODE("endpoint@0", swnodes->ports[port_index].ep_props,
+			      &swnodes->nodes[ACPI_DEVICE_SWNODE_PORT(port_index)]);
+
+	if (port->crs_csi2_local)
+		init_csi2_port_local(adev, port, port_fwnode, ep_prop_index);
+}
+
+#define MIPI_IMG_PORT_PREFIX "mipi-img-port-"
+
+static struct fwnode_handle *get_mipi_port_handle(struct fwnode_handle *adev_fwnode,
+						  unsigned int port_nr)
+{
+	char port_name[sizeof(MIPI_IMG_PORT_PREFIX) + 2];
+
+	if (snprintf(port_name, sizeof(port_name), "%s%u",
+		     MIPI_IMG_PORT_PREFIX, port_nr) >= sizeof(port_name))
+		return NULL;
+
+	return fwnode_get_named_child_node(adev_fwnode, port_name);
+}
+
+static void init_crs_csi2_swnodes(struct crs_csi2 *csi2)
+{
+	struct acpi_buffer buffer = { .length = ACPI_ALLOCATE_BUFFER };
+	struct acpi_device_software_nodes *swnodes = csi2->swnodes;
+	acpi_handle handle = csi2->handle;
+	struct fwnode_handle *adev_fwnode;
+	struct acpi_device *adev;
+	acpi_status status;
+	unsigned int i;
+	int ret;
+
+	/*
+	 * Bail out if the swnodes are not available (either they have not been
+	 * allocated or they have been assigned to the device already).
+	 */
+	if (!swnodes)
+		return;
+
+	adev = acpi_fetch_acpi_dev(handle);
+	if (!adev)
+		return;
+
+	adev_fwnode = acpi_fwnode_handle(adev);
+
+	status = acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
+	if (ACPI_FAILURE(status)) {
+		acpi_handle_info(handle, "Unable to get the path name\n");
+		return;
+	}
+
+	swnodes->nodes[ACPI_DEVICE_SWNODE_ROOT] =
+			SOFTWARE_NODE(buffer.pointer, swnodes->dev_props, NULL);
+
+	for (i = 0; i < swnodes->num_ports; i++) {
+		struct acpi_device_software_node_port *port = &swnodes->ports[i];
+		struct fwnode_handle *port_fwnode;
+
+		/*
+		 * The MIPI DisCo for Imaging specification defines _DSD device
+		 * properties for providing CSI-2 port parameters that can be
+		 * accessed through the generic device properties framework.  To
+		 * access them, it is first necessary to find the data node
+		 * representing the port under the given ACPI device object.
+		 */
+		port_fwnode = get_mipi_port_handle(adev_fwnode, port->port_nr);
+		if (!port_fwnode) {
+			acpi_handle_info(handle,
+					 "MIPI port name too long for port %u\n",
+					 port->port_nr);
+			continue;
+		}
+
+		init_csi2_port(adev, swnodes, port, port_fwnode, i);
+
+		fwnode_handle_put(port_fwnode);
+	}
+
+	ret = software_node_register_node_group(swnodes->nodeptrs);
+	if (ret < 0) {
+		acpi_handle_info(handle,
+				 "Unable to register software nodes (%d)\n", ret);
+		return;
+	}
+
+	adev->swnodes = swnodes;
+	adev_fwnode->secondary = software_node_fwnode(swnodes->nodes);
+
+	/*
+	 * Prevents the swnodes from this csi2 entry from being assigned again
+	 * or freed prematurely.
+	 */
+	csi2->swnodes = NULL;
+}
+
+/**
+ * acpi_mipi_init_crs_csi2_swnodes - Initialize _CRS CSI-2 software nodes
+ *
+ * Use MIPI DiSco for Imaging device properties to finalize the initialization
+ * of CSI-2 software nodes for all ACPI device objects that have been already
+ * enumerated.
+ */
+void acpi_mipi_init_crs_csi2_swnodes(void)
+{
+	struct crs_csi2 *csi2, *csi2_tmp;
+
+	list_for_each_entry_safe(csi2, csi2_tmp, &acpi_mipi_crs_csi2_list, entry)
+		init_crs_csi2_swnodes(csi2);
+}
+
 /**
  * acpi_mipi_crs_csi2_cleanup - Free _CRS CSI-2 temporary data
  */
Index: linux-pm/drivers/acpi/internal.h
===================================================================
--- linux-pm.orig/drivers/acpi/internal.h
+++ linux-pm/drivers/acpi/internal.h
@@ -287,6 +287,7 @@ static inline void acpi_init_lpit(void)
 
 void acpi_mipi_check_crs_csi2(acpi_handle handle);
 void acpi_mipi_scan_crs_csi2(void);
+void acpi_mipi_init_crs_csi2_swnodes(void);
 void acpi_mipi_crs_csi2_cleanup(void);
 
 #endif /* _ACPI_INTERNAL_H_ */
Index: linux-pm/drivers/acpi/scan.c
===================================================================
--- linux-pm.orig/drivers/acpi/scan.c
+++ linux-pm/drivers/acpi/scan.c
@@ -2447,6 +2447,13 @@ static void acpi_scan_postponed_branch(a
 
 	acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 			    acpi_bus_check_add_2, NULL, NULL, (void **)&adev);
+
+	/*
+	 * Populate the ACPI _CRS CSI-2 software nodes for the ACPI devices that
+	 * have been added above.
+	 */
+	acpi_mipi_init_crs_csi2_swnodes();
+
 	acpi_bus_attach(adev, NULL);
 }
 
@@ -2516,11 +2523,12 @@ int acpi_bus_scan(acpi_handle handle)
 		return -ENODEV;
 
 	/*
-	 * Allocate ACPI _CRS CSI-2 software nodes using information extracted
+	 * Set up ACPI _CRS CSI-2 software nodes using information extracted
 	 * from the _CRS CSI-2 resource descriptors during the ACPI namespace
-	 * walk above.
+	 * walk above and MIPI DiSco for Imaging device properties.
 	 */
 	acpi_mipi_scan_crs_csi2();
+	acpi_mipi_init_crs_csi2_swnodes();
 
 	acpi_bus_attach(device, (void *)true);
 
Index: linux-pm/include/acpi/acpi_bus.h
===================================================================
--- linux-pm.orig/include/acpi/acpi_bus.h
+++ linux-pm/include/acpi/acpi_bus.h
@@ -366,10 +366,17 @@ struct acpi_device_data {
 
 struct acpi_gpio_mapping;
 
+#define ACPI_DEVICE_SWNODE_ROOT			0
+
 #define ACPI_DEVICE_CSI2_DATA_LANES		4
 
 #define ACPI_DEVICE_SWNODE_PORT_NAME_LENGTH	8
 
+enum acpi_device_swnode_dev_props {
+	ACPI_DEVICE_SWNODE_DEV_NUM_OF,
+	ACPI_DEVICE_SWNODE_DEV_NUM_ENTRIES
+};
+
 enum acpi_device_swnode_port_props {
 	ACPI_DEVICE_SWNODE_PORT_REG,
 	ACPI_DEVICE_SWNODE_PORT_NUM_OF,
@@ -425,12 +432,14 @@ struct acpi_device_software_node_port {
 
 /**
  * struct acpi_device_software_nodes - Software nodes for an ACPI device
+ * @dev_props: Device properties.
  * @nodes: Software nodes for root as well as ports and endpoints.
  * @nodeprts: Array of software node pointers, for (un)registering them.
  * @ports: Information related to each port and endpoint within a port.
  * @num_ports: The number of ports.
  */
 struct acpi_device_software_nodes {
+	struct property_entry dev_props[ACPI_DEVICE_SWNODE_DEV_NUM_ENTRIES];
 	struct software_node *nodes;
 	const struct software_node **nodeptrs;
 	struct acpi_device_software_node_port *ports;
@@ -455,6 +464,7 @@ struct acpi_device {
 	struct acpi_device_data data;
 	struct acpi_scan_handler *handler;
 	struct acpi_hotplug_context *hp;
+	struct acpi_device_software_nodes *swnodes;
 	const struct acpi_gpio_mapping *driver_gpios;
 	void *driver_data;
 	struct device dev;

[PATCH v2 6/6] ACPI: property: Dig "rotation" property for devices with CSI2 _CRS

[Rafael J. Wysocki]

From: Sakari Ailus <sakari.ailus@linux.intel.com>

Find the "rotation" property value for devices with _CRS CSI-2 resource
descriptors and use it to add the "rotation" property to the software
nodes representing the CSI-2 connection graph.  That value typically
comes from the _PLD (Physical Location of Device) object if it is
present for the given device.

This way, camera sensor drivers that know the "rotation" property do not
need to care about _PLD on systems using ACPI.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
[ rjw: Changelog edits, file rename ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/acpi/mipi-di.c  |   17 +++++++++++++++++
 include/acpi/acpi_bus.h |    1 +
 2 files changed, 18 insertions(+)

Index: linux-pm/drivers/acpi/mipi-di.c
===================================================================
--- linux-pm.orig/drivers/acpi/mipi-di.c
+++ linux-pm/drivers/acpi/mipi-di.c
@@ -586,6 +586,7 @@ static void init_crs_csi2_swnodes(struct
 	struct acpi_buffer buffer = { .length = ACPI_ALLOCATE_BUFFER };
 	struct acpi_device_software_nodes *swnodes = csi2->swnodes;
 	acpi_handle handle = csi2->handle;
+	unsigned int prop_index = 0;
 	struct fwnode_handle *adev_fwnode;
 	struct acpi_device *adev;
 	acpi_status status;
@@ -605,6 +606,22 @@ static void init_crs_csi2_swnodes(struct
 
 	adev_fwnode = acpi_fwnode_handle(adev);
 
+	/*
+	 * If the "rotation" property is not present, but _PLD is there,
+	 * evaluate it to get the "rotation" value.
+	 */
+	if (!fwnode_property_present(adev_fwnode, "rotation")) {
+		struct acpi_pld_info *pld;
+
+		status = acpi_get_physical_device_location(handle, &pld);
+		if (ACPI_SUCCESS(status)) {
+			swnodes->dev_props[NEXT_PROPERTY(prop_index, DEV_ROTATION)] =
+					PROPERTY_ENTRY_U32("rotation",
+							   pld->rotation * 45U);
+			kfree(pld);
+		}
+	}
+
 	status = acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
 	if (ACPI_FAILURE(status)) {
 		acpi_handle_info(handle, "Unable to get the path name\n");
Index: linux-pm/include/acpi/acpi_bus.h
===================================================================
--- linux-pm.orig/include/acpi/acpi_bus.h
+++ linux-pm/include/acpi/acpi_bus.h
@@ -373,6 +373,7 @@ struct acpi_gpio_mapping;
 #define ACPI_DEVICE_SWNODE_PORT_NAME_LENGTH	8
 
 enum acpi_device_swnode_dev_props {
+	ACPI_DEVICE_SWNODE_DEV_ROTATION,
 	ACPI_DEVICE_SWNODE_DEV_NUM_OF,
 	ACPI_DEVICE_SWNODE_DEV_NUM_ENTRIES
 };

Re: [PATCH v2 0/6] ACPI: scan: MIPI DiSco for Imaging support

[Sakari Ailus]

Hi Rafael,

On Fri, Oct 20, 2023 at 04:33:56PM +0200, Rafael J. Wysocki wrote:
> Hi Folks,
> 
> This is a new revision of
> 
> https://lore.kernel.org/linux-acpi/13276375.uLZWGnKmhe@kreacher/
> 
> which was reported to have issues and it took time to revisit it.
> 
> > The main points from the original cover letter are still valid:
> > 
> > The general idea is the same - CSI-2 resource descriptors, introduced in
> > ACPI 6.4 and defined by
> > 
> > https://uefi.org/specs/ACPI/6.5/06_Device_Configuration.html#camera-serial-i
> > nterface-csi-2-connection-resource-descriptor
> > 
> > are found and used for creating a set of software nodes that represent the
> > CSI-2 connection graph.
> > 
> > These software nodes need to be available before any scan handlers or ACPI
> > drivers are bound to any struct acpi_device objects, so all of that is done
> > at the early stage of ACPI device enumeration, but unnecessary ACPI
> > namespace walks are avoided.
> > 
> > The CSI-2 software nodes are populated with data extracted from the CSI-2
> > resource descriptors themselves and from device properties defined by the
> > MIPI DiSco for Imaging specification (see
> > https://www.mipi.org/specifications/mipi-disco-imaging).
> > 
> > Patches [4,6/6] come from the original series directly, but the other
> > patches have been changes substantially, so I've decided to re-start patch
> > series versioning from scratch.
> 
> The v2 addresses at least 3 issues found in the v1 by code inspection:
> 
> * A port_count field incrementation was missing in acpi_mipi_scan_crs_csi2(),
>   so its value for all of the devices having CSI2 resources in _CRS was always
>   1 (and it should be equal to the number of valid CSI2 connection resources).
> 
> * Some acpi_mipi_crs_csi2_list members could be freed prematurely, so they were
>   inaccessible when extract_crs_csi2_conn_info() attempted to access them.
> 
> * A check of remote_swnodes() against NULL was missing, which could result in
>   a crash in a case when the swnodes memory could not be allocated for some
>   acpi_mipi_crs_csi2_list entries.
> 
> Apart from that, it rearranges the code somewhat to make it easier to follow
> and to avoid premature freeing of memory in it in general and the new file
> added by it is now called mipi-di.c (instead of mipi-disco-imaging.c) for
> compactness.
> 
> The series is based on current linux-next.

Thanks for the update. I've tested this and I can confirm it works, to the
extent implemented in the set. The rest can be implemented on top
(mainly replicating properties).

I'll comment on a few patches in the set.

Do you prefer to make the changes or shall I? I presume them to be fairly
minor.

-- 
Regards,

Sakari Ailus

Re: [PATCH v2 2/6] ACPI: scan: Extract CSI-2 connection graph from _CRS

[Sakari Ailus]

Hi Rafael,

On Fri, Oct 20, 2023 at 04:36:28PM +0200, Rafael J. Wysocki wrote:
> +#define NO_CSI2_PORT (UINT_MAX - 1)
> +
> +static void alloc_crs_csi2_swnodes(struct crs_csi2 *csi2)
> +{
> +	size_t port_count = csi2->port_count;
> +	struct acpi_device_software_nodes *swnodes;
> +	size_t alloc_size;
> +	unsigned int i;
> +
> +	/*
> +	 * Allocate memory for ports, node pointers (number of nodes +
> +	 * 1 (guardian), nodes (root + number of ports * 2 (because for
> +	 * every port there is an endpoint)).
> +	 */
> +	if (check_mul_overflow(sizeof(*swnodes->ports) +
> +			       sizeof(*swnodes->nodes) * 2 +
> +			       sizeof(*swnodes->nodeptrs) * 2,
> +			       port_count, &alloc_size))
> +		goto overflow;
> +
> +	if (check_add_overflow(sizeof(*swnodes) +
> +			       sizeof(*swnodes->nodes) +
> +			       sizeof(*swnodes->nodeptrs) * 2,
> +			       alloc_size, &alloc_size))
> +		goto overflow;
> +
> +	swnodes = kmalloc(alloc_size, GFP_KERNEL);
> +	if (!swnodes)
> +		return;
> +
> +	swnodes->ports = (struct acpi_device_software_node_port *)(swnodes + 1);
> +	swnodes->nodes = (struct software_node *)(swnodes->ports + port_count);
> +	swnodes->nodeptrs = (const struct software_node **)(swnodes->nodes + 1 +
> +				2 * port_count);
> +	swnodes->num_ports = port_count;
> +
> +	for (i = 0; i < 2 * port_count + 1; i++)
> +		swnodes->nodeptrs[i] = &swnodes->nodes[i];
> +
> +	swnodes->nodeptrs[i] = NULL;
> +
> +	for (i = 0; i < port_count; i++)
> +		swnodes->ports[i].port_nr = NO_CSI2_PORT;
> +
> +	csi2->swnodes = swnodes;
> +	return;
> +
> +overflow:
> +	acpi_handle_info(csi2->handle, "too many _CRS CSI-2 resource handles (%zu)",
> +			 port_count);

I'd move this to where the conditions are, they can be merged.

-- 
Regards,

Sakari Ailus

Re: [PATCH v2 5/6] ACPI: scan: Extract MIPI DiSco for Imaging data into swnodes

[Sakari Ailus]

Hi Rafael,

On subject:

s/DiSco/DisCo/

On Fri, Oct 20, 2023 at 04:39:27PM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> Add information extracted from the MIPI DiSco for Imaging device

Ditto.

> properties to software nodes created during the CSI-2 connection graph
> discovery.
> 
> Link: https://www.mipi.org/specifications/mipi-di

This URL is broken. The correct URL is:

	https://www.mipi.org/specifications/mipi-disco-imaging

> Co-developed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
>  drivers/acpi/internal.h |    1 
>  drivers/acpi/mipi-di.c  |  240 +++++++++++++++++++++++++++++++++++++++++++++++-

How about mipi-disco.c? I wouldn't mind having mipi-disco-imaging.c either.

>  drivers/acpi/scan.c     |   12 ++
>  include/acpi/acpi_bus.h |   10 ++
>  4 files changed, 259 insertions(+), 4 deletions(-)
> 
> Index: linux-pm/drivers/acpi/mipi-di.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/mipi-di.c
> +++ linux-pm/drivers/acpi/mipi-di.c
> @@ -6,12 +6,16 @@
>   *
>   * Support MIPI DisCo for Imaging by parsing ACPI _CRS CSI-2 records defined in
>   * Section 6.4.3.8.2.4 "Camera Serial Interface (CSI-2) Connection Resource
> - * Descriptor" of ACPI 6.5.
> + * Descriptor" of ACPI 6.5 and using device properties defined by the MIPI DisCo
> + * for Imaging specification.
>   *
>   * The implementation looks for the information in the ACPI namespace (CSI-2
>   * resource descriptors in _CRS) and constructs software nodes compatible with
>   * Documentation/firmware-guide/acpi/dsd/graph.rst to represent the CSI-2
> - * connection graph.
> + * connection graph.  The software nodes are then populated with the data
> + * extracted from the _CRS CSI-2 resource descriptors and the MIPI DisCo
> + * for Imaging device properties present in _DSD for the ACPI device objects
> + * with CSI-2 connections.
>   */
>  
>  #include <linux/acpi.h>
> @@ -434,6 +438,238 @@ void acpi_mipi_scan_crs_csi2(void)
>  		prepare_crs_csi2_swnodes(csi2);
>  }
>  
> +/*
> + * Get the index of the next property in the property array, with a given
> + * maximum value.
> + */
> +#define NEXT_PROPERTY(index, max)			\
> +	(WARN_ON((index) > ACPI_DEVICE_SWNODE_##max) ?	\
> +	 ACPI_DEVICE_SWNODE_##max : (index)++)
> +
> +static void init_csi2_port_local(struct acpi_device *adev,
> +				 struct acpi_device_software_node_port *port,
> +				 struct fwnode_handle *port_fwnode,
> +				 unsigned int index)
> +{
> +	acpi_handle handle = acpi_device_handle(adev);
> +	unsigned int num_link_freqs;
> +	int ret;
> +
> +	ret = fwnode_property_count_u64(port_fwnode, "mipi-img-link-frequencies");
> +	if (ret <= 0)
> +		return;
> +
> +	num_link_freqs = ret;
> +	if (num_link_freqs > ARRAY_SIZE(port->link_frequencies)) {
> +		acpi_handle_info(handle, "Too many link frequencies: %u\n",
> +				 num_link_freqs);
> +		num_link_freqs = ARRAY_SIZE(port->link_frequencies);
> +	}
> +
> +	ret = fwnode_property_read_u64_array(port_fwnode,
> +					     "mipi-img-link-frequencies",
> +					     port->link_frequencies,
> +					     num_link_freqs);
> +	if (ret) {
> +		acpi_handle_info(handle, "Unable to get link frequencies (%d)\n",
> +				 ret);
> +		return;
> +	}
> +
> +	port->ep_props[NEXT_PROPERTY(index, EP_LINK_FREQUENCIES)] =
> +				PROPERTY_ENTRY_U64_ARRAY_LEN("link-frequencies",
> +							     port->link_frequencies,
> +							     num_link_freqs);
> +}
> +
> +static void init_csi2_port(struct acpi_device *adev,
> +			   struct acpi_device_software_nodes *swnodes,
> +			   struct acpi_device_software_node_port *port,
> +			   struct fwnode_handle *port_fwnode,
> +			   unsigned int port_index)
> +{
> +	unsigned int ep_prop_index = ACPI_DEVICE_SWNODE_EP_CLOCK_LANES;
> +	acpi_handle handle = acpi_device_handle(adev);
> +	u8 val[ARRAY_SIZE(port->data_lanes)];
> +	unsigned int num_lanes = 0;
> +	int ret;
> +
> +	if (GRAPH_PORT_NAME(port->port_name, port->port_nr))
> +		return;
> +
> +	swnodes->nodes[ACPI_DEVICE_SWNODE_PORT(port_index)] =
> +			SOFTWARE_NODE(port->port_name, port->port_props,
> +				      &swnodes->nodes[ACPI_DEVICE_SWNODE_ROOT]);
> +
> +	ret = fwnode_property_read_u8(port_fwnode, "mipi-img-clock-lane", val);
> +	if (!ret)
> +		port->ep_props[NEXT_PROPERTY(ep_prop_index, EP_CLOCK_LANES)] =
> +			PROPERTY_ENTRY_U32("clock-lanes", val[0]);
> +
> +	ret = fwnode_property_count_u8(port_fwnode, "mipi-img-data-lanes");
> +	if (ret > 0) {
> +		num_lanes = ret;
> +
> +		if (num_lanes > ARRAY_SIZE(port->data_lanes)) {
> +			acpi_handle_info(handle, "Too many data lanes: %u\n",
> +					 num_lanes);
> +			num_lanes = ARRAY_SIZE(port->data_lanes);
> +		}
> +
> +		ret = fwnode_property_read_u8_array(port_fwnode,
> +						    "mipi-img-data-lanes",
> +						    val, num_lanes);
> +		if (!ret) {
> +			unsigned int i;
> +
> +			for (i = 0; i < num_lanes; i++)
> +				port->data_lanes[i] = val[i];
> +
> +			port->ep_props[NEXT_PROPERTY(ep_prop_index, EP_DATA_LANES)] =
> +				PROPERTY_ENTRY_U32_ARRAY_LEN("data-lanes",
> +							     port->data_lanes,
> +							     num_lanes);
> +		}
> +	}
> +
> +	ret = fwnode_property_count_u8(port_fwnode, "mipi-img-lane-polarities");
> +	if (ret > 0) {
> +		unsigned long mask;
> +		unsigned int i;
> +
> +		/*
> +		 * Total number of lanes here is clock lane + data lanes.
> +		 * Require that number to be low enough so they all can be
> +		 * covered by the bits in one byte.
> +		 */
> +		BUILD_BUG_ON(BITS_PER_TYPE(u8) <= ARRAY_SIZE(port->data_lanes));
> +
> +		fwnode_property_read_u8_array(port_fwnode,
> +					      "mipi-img-lane-polarities",
> +					      val, 1);
> +
> +		for (mask = val[0], i = 0; i < num_lanes + 1; i++)
> +			port->lane_polarities[i] = test_bit(i, &mask);

This works only up to seven lanes. I guess this can be addressed later in
case we get devices with 8 lanes. But adding a comment here (or where the
maximum number of lanes is defined) that this needs to be fixed would be
prudent to avoid introducing a bug later on.

> +
> +		port->ep_props[NEXT_PROPERTY(ep_prop_index, EP_LANE_POLARITIES)] =
> +				PROPERTY_ENTRY_U32_ARRAY_LEN("lane-polarities",
> +							     port->lane_polarities,
> +							     1 + num_lanes);
> +	} else {
> +		acpi_handle_info(handle, "No lane polarity bytes\n");
> +	}
> +
> +	swnodes->nodes[ACPI_DEVICE_SWNODE_EP(port_index)] =
> +		SOFTWARE_NODE("endpoint@0", swnodes->ports[port_index].ep_props,
> +			      &swnodes->nodes[ACPI_DEVICE_SWNODE_PORT(port_index)]);
> +
> +	if (port->crs_csi2_local)
> +		init_csi2_port_local(adev, port, port_fwnode, ep_prop_index);
> +}
> +
> +#define MIPI_IMG_PORT_PREFIX "mipi-img-port-"
> +
> +static struct fwnode_handle *get_mipi_port_handle(struct fwnode_handle *adev_fwnode,
> +						  unsigned int port_nr)
> +{
> +	char port_name[sizeof(MIPI_IMG_PORT_PREFIX) + 2];
> +
> +	if (snprintf(port_name, sizeof(port_name), "%s%u",
> +		     MIPI_IMG_PORT_PREFIX, port_nr) >= sizeof(port_name))
> +		return NULL;
> +
> +	return fwnode_get_named_child_node(adev_fwnode, port_name);
> +}
> +
> +static void init_crs_csi2_swnodes(struct crs_csi2 *csi2)
> +{
> +	struct acpi_buffer buffer = { .length = ACPI_ALLOCATE_BUFFER };
> +	struct acpi_device_software_nodes *swnodes = csi2->swnodes;
> +	acpi_handle handle = csi2->handle;
> +	struct fwnode_handle *adev_fwnode;
> +	struct acpi_device *adev;
> +	acpi_status status;
> +	unsigned int i;
> +	int ret;
> +
> +	/*
> +	 * Bail out if the swnodes are not available (either they have not been
> +	 * allocated or they have been assigned to the device already).
> +	 */
> +	if (!swnodes)
> +		return;
> +
> +	adev = acpi_fetch_acpi_dev(handle);
> +	if (!adev)
> +		return;
> +
> +	adev_fwnode = acpi_fwnode_handle(adev);
> +
> +	status = acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
> +	if (ACPI_FAILURE(status)) {
> +		acpi_handle_info(handle, "Unable to get the path name\n");
> +		return;
> +	}
> +
> +	swnodes->nodes[ACPI_DEVICE_SWNODE_ROOT] =
> +			SOFTWARE_NODE(buffer.pointer, swnodes->dev_props, NULL);
> +
> +	for (i = 0; i < swnodes->num_ports; i++) {
> +		struct acpi_device_software_node_port *port = &swnodes->ports[i];
> +		struct fwnode_handle *port_fwnode;
> +
> +		/*
> +		 * The MIPI DisCo for Imaging specification defines _DSD device
> +		 * properties for providing CSI-2 port parameters that can be
> +		 * accessed through the generic device properties framework.  To
> +		 * access them, it is first necessary to find the data node
> +		 * representing the port under the given ACPI device object.
> +		 */
> +		port_fwnode = get_mipi_port_handle(adev_fwnode, port->port_nr);
> +		if (!port_fwnode) {
> +			acpi_handle_info(handle,
> +					 "MIPI port name too long for port %u\n",
> +					 port->port_nr);
> +			continue;
> +		}
> +
> +		init_csi2_port(adev, swnodes, port, port_fwnode, i);
> +
> +		fwnode_handle_put(port_fwnode);
> +	}
> +
> +	ret = software_node_register_node_group(swnodes->nodeptrs);
> +	if (ret < 0) {
> +		acpi_handle_info(handle,
> +				 "Unable to register software nodes (%d)\n", ret);
> +		return;
> +	}
> +
> +	adev->swnodes = swnodes;
> +	adev_fwnode->secondary = software_node_fwnode(swnodes->nodes);
> +
> +	/*
> +	 * Prevents the swnodes from this csi2 entry from being assigned again
> +	 * or freed prematurely.
> +	 */
> +	csi2->swnodes = NULL;
> +}
> +
> +/**
> + * acpi_mipi_init_crs_csi2_swnodes - Initialize _CRS CSI-2 software nodes
> + *
> + * Use MIPI DiSco for Imaging device properties to finalize the initialization
> + * of CSI-2 software nodes for all ACPI device objects that have been already
> + * enumerated.
> + */
> +void acpi_mipi_init_crs_csi2_swnodes(void)
> +{
> +	struct crs_csi2 *csi2, *csi2_tmp;
> +
> +	list_for_each_entry_safe(csi2, csi2_tmp, &acpi_mipi_crs_csi2_list, entry)
> +		init_crs_csi2_swnodes(csi2);
> +}
> +
>  /**
>   * acpi_mipi_crs_csi2_cleanup - Free _CRS CSI-2 temporary data
>   */
> Index: linux-pm/drivers/acpi/internal.h
> ===================================================================
> --- linux-pm.orig/drivers/acpi/internal.h
> +++ linux-pm/drivers/acpi/internal.h
> @@ -287,6 +287,7 @@ static inline void acpi_init_lpit(void)
>  
>  void acpi_mipi_check_crs_csi2(acpi_handle handle);
>  void acpi_mipi_scan_crs_csi2(void);
> +void acpi_mipi_init_crs_csi2_swnodes(void);
>  void acpi_mipi_crs_csi2_cleanup(void);
>  
>  #endif /* _ACPI_INTERNAL_H_ */
> Index: linux-pm/drivers/acpi/scan.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/scan.c
> +++ linux-pm/drivers/acpi/scan.c
> @@ -2447,6 +2447,13 @@ static void acpi_scan_postponed_branch(a
>  
>  	acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
>  			    acpi_bus_check_add_2, NULL, NULL, (void **)&adev);
> +
> +	/*
> +	 * Populate the ACPI _CRS CSI-2 software nodes for the ACPI devices that
> +	 * have been added above.
> +	 */
> +	acpi_mipi_init_crs_csi2_swnodes();
> +
>  	acpi_bus_attach(adev, NULL);
>  }
>  
> @@ -2516,11 +2523,12 @@ int acpi_bus_scan(acpi_handle handle)
>  		return -ENODEV;
>  
>  	/*
> -	 * Allocate ACPI _CRS CSI-2 software nodes using information extracted
> +	 * Set up ACPI _CRS CSI-2 software nodes using information extracted
>  	 * from the _CRS CSI-2 resource descriptors during the ACPI namespace
> -	 * walk above.
> +	 * walk above and MIPI DiSco for Imaging device properties.
>  	 */
>  	acpi_mipi_scan_crs_csi2();
> +	acpi_mipi_init_crs_csi2_swnodes();
>  
>  	acpi_bus_attach(device, (void *)true);
>  
> Index: linux-pm/include/acpi/acpi_bus.h
> ===================================================================
> --- linux-pm.orig/include/acpi/acpi_bus.h
> +++ linux-pm/include/acpi/acpi_bus.h
> @@ -366,10 +366,17 @@ struct acpi_device_data {
>  
>  struct acpi_gpio_mapping;
>  
> +#define ACPI_DEVICE_SWNODE_ROOT			0
> +
>  #define ACPI_DEVICE_CSI2_DATA_LANES		4
>  
>  #define ACPI_DEVICE_SWNODE_PORT_NAME_LENGTH	8
>  
> +enum acpi_device_swnode_dev_props {
> +	ACPI_DEVICE_SWNODE_DEV_NUM_OF,
> +	ACPI_DEVICE_SWNODE_DEV_NUM_ENTRIES
> +};
> +
>  enum acpi_device_swnode_port_props {
>  	ACPI_DEVICE_SWNODE_PORT_REG,
>  	ACPI_DEVICE_SWNODE_PORT_NUM_OF,
> @@ -425,12 +432,14 @@ struct acpi_device_software_node_port {
>  
>  /**
>   * struct acpi_device_software_nodes - Software nodes for an ACPI device
> + * @dev_props: Device properties.
>   * @nodes: Software nodes for root as well as ports and endpoints.
>   * @nodeprts: Array of software node pointers, for (un)registering them.
>   * @ports: Information related to each port and endpoint within a port.
>   * @num_ports: The number of ports.
>   */
>  struct acpi_device_software_nodes {
> +	struct property_entry dev_props[ACPI_DEVICE_SWNODE_DEV_NUM_ENTRIES];
>  	struct software_node *nodes;
>  	const struct software_node **nodeptrs;
>  	struct acpi_device_software_node_port *ports;
> @@ -455,6 +464,7 @@ struct acpi_device {
>  	struct acpi_device_data data;
>  	struct acpi_scan_handler *handler;
>  	struct acpi_hotplug_context *hp;
> +	struct acpi_device_software_nodes *swnodes;
>  	const struct acpi_gpio_mapping *driver_gpios;
>  	void *driver_data;
>  	struct device dev;
> 
> 
> 

-- 
Regards,

Sakari Ailus

Re: [PATCH v2 0/6] ACPI: scan: MIPI DiSco for Imaging support

[Rafael J. Wysocki]

Hi Sakari,

On Tue, Oct 31, 2023 at 11:33 AM Sakari Ailus
<sakari.ailus@linux.intel.com> wrote:
>
> Hi Rafael,

[cut]

> > The v2 addresses at least 3 issues found in the v1 by code inspection:
> >
> > * A port_count field incrementation was missing in acpi_mipi_scan_crs_csi2(),
> >   so its value for all of the devices having CSI2 resources in _CRS was always
> >   1 (and it should be equal to the number of valid CSI2 connection resources).
> >
> > * Some acpi_mipi_crs_csi2_list members could be freed prematurely, so they were
> >   inaccessible when extract_crs_csi2_conn_info() attempted to access them.
> >
> > * A check of remote_swnodes() against NULL was missing, which could result in
> >   a crash in a case when the swnodes memory could not be allocated for some
> >   acpi_mipi_crs_csi2_list entries.
> >
> > Apart from that, it rearranges the code somewhat to make it easier to follow
> > and to avoid premature freeing of memory in it in general and the new file
> > added by it is now called mipi-di.c (instead of mipi-disco-imaging.c) for
> > compactness.
> >
> > The series is based on current linux-next.
>
> Thanks for the update. I've tested this and I can confirm it works, to the
> extent implemented in the set. The rest can be implemented on top
> (mainly replicating properties).

Thanks for testing!

> I'll comment on a few patches in the set.
>
> Do you prefer to make the changes or shall I? I presume them to be fairly
> minor.

I can make the changes.

Re: [PATCH v2 2/6] ACPI: scan: Extract CSI-2 connection graph from _CRS

[Rafael J. Wysocki]

Hi Sakari,

On Tue, Oct 31, 2023 at 11:33 AM Sakari Ailus
<sakari.ailus@linux.intel.com> wrote:
>
> Hi Rafael,
>
> On Fri, Oct 20, 2023 at 04:36:28PM +0200, Rafael J. Wysocki wrote:
> > +#define NO_CSI2_PORT (UINT_MAX - 1)
> > +
> > +static void alloc_crs_csi2_swnodes(struct crs_csi2 *csi2)
> > +{
> > +     size_t port_count = csi2->port_count;
> > +     struct acpi_device_software_nodes *swnodes;
> > +     size_t alloc_size;
> > +     unsigned int i;
> > +
> > +     /*
> > +      * Allocate memory for ports, node pointers (number of nodes +
> > +      * 1 (guardian), nodes (root + number of ports * 2 (because for
> > +      * every port there is an endpoint)).
> > +      */
> > +     if (check_mul_overflow(sizeof(*swnodes->ports) +
> > +                            sizeof(*swnodes->nodes) * 2 +
> > +                            sizeof(*swnodes->nodeptrs) * 2,
> > +                            port_count, &alloc_size))
> > +             goto overflow;
> > +
> > +     if (check_add_overflow(sizeof(*swnodes) +
> > +                            sizeof(*swnodes->nodes) +
> > +                            sizeof(*swnodes->nodeptrs) * 2,
> > +                            alloc_size, &alloc_size))
> > +             goto overflow;
> > +
> > +     swnodes = kmalloc(alloc_size, GFP_KERNEL);
> > +     if (!swnodes)
> > +             return;
> > +
> > +     swnodes->ports = (struct acpi_device_software_node_port *)(swnodes + 1);
> > +     swnodes->nodes = (struct software_node *)(swnodes->ports + port_count);
> > +     swnodes->nodeptrs = (const struct software_node **)(swnodes->nodes + 1 +
> > +                             2 * port_count);
> > +     swnodes->num_ports = port_count;
> > +
> > +     for (i = 0; i < 2 * port_count + 1; i++)
> > +             swnodes->nodeptrs[i] = &swnodes->nodes[i];
> > +
> > +     swnodes->nodeptrs[i] = NULL;
> > +
> > +     for (i = 0; i < port_count; i++)
> > +             swnodes->ports[i].port_nr = NO_CSI2_PORT;
> > +
> > +     csi2->swnodes = swnodes;
> > +     return;
> > +
> > +overflow:
> > +     acpi_handle_info(csi2->handle, "too many _CRS CSI-2 resource handles (%zu)",
> > +                      port_count);
>
> I'd move this to where the conditions are, they can be merged.

No problem.

Re: [PATCH v2 5/6] ACPI: scan: Extract MIPI DiSco for Imaging data into swnodes

[Rafael J. Wysocki]

Hi Sakari,

On Tue, Oct 31, 2023 at 11:33 AM Sakari Ailus
<sakari.ailus@linux.intel.com> wrote:
>
> Hi Rafael,
>
> On subject:
>
> s/DiSco/DisCo/

Huh

Thanks for catching this!

> On Fri, Oct 20, 2023 at 04:39:27PM +0200, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> >
> > Add information extracted from the MIPI DiSco for Imaging device
>
> Ditto.
>
> > properties to software nodes created during the CSI-2 connection graph
> > discovery.
> >
> > Link: https://www.mipi.org/specifications/mipi-di
>
> This URL is broken. The correct URL is:
>
>         https://www.mipi.org/specifications/mipi-disco-imaging

OK

> > Co-developed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > ---
> >  drivers/acpi/internal.h |    1
> >  drivers/acpi/mipi-di.c  |  240 +++++++++++++++++++++++++++++++++++++++++++++++-
>
> How about mipi-disco.c? I wouldn't mind having mipi-disco-imaging.c either.

Well, mipi-disco-imaging is a bit too long and the meaning of
mipi-disco would not be clear IMO.

What about mipi-disco-img?

[cut]

> > +     ret = fwnode_property_count_u8(port_fwnode, "mipi-img-lane-polarities");
> > +     if (ret > 0) {
> > +             unsigned long mask;
> > +             unsigned int i;
> > +
> > +             /*
> > +              * Total number of lanes here is clock lane + data lanes.
> > +              * Require that number to be low enough so they all can be
> > +              * covered by the bits in one byte.
> > +              */
> > +             BUILD_BUG_ON(BITS_PER_TYPE(u8) <= ARRAY_SIZE(port->data_lanes));
> > +
> > +             fwnode_property_read_u8_array(port_fwnode,
> > +                                           "mipi-img-lane-polarities",
> > +                                           val, 1);
> > +
> > +             for (mask = val[0], i = 0; i < num_lanes + 1; i++)
> > +                     port->lane_polarities[i] = test_bit(i, &mask);
>
> This works only up to seven lanes.

True, but then ACPI_DEVICE_CSI2_DATA_LANES is defined as 4.

> I guess this can be addressed later in
> case we get devices with 8 lanes. But adding a comment here (or where the
> maximum number of lanes is defined) that this needs to be fixed would be
> prudent to avoid introducing a bug later on.

The comment above talks about this, but I can add one more comment
next to the ACPI_DEVICE_CSI2_DATA_LANES definition.

> > +
> > +             port->ep_props[NEXT_PROPERTY(ep_prop_index, EP_LANE_POLARITIES)] =
> > +                             PROPERTY_ENTRY_U32_ARRAY_LEN("lane-polarities",
> > +                                                          port->lane_polarities,
> > +                                                          1 + num_lanes);
> > +     } else {
> > +             acpi_handle_info(handle, "No lane polarity bytes\n");
> > +     }
> > +
> > +     swnodes->nodes[ACPI_DEVICE_SWNODE_EP(port_index)] =
> > +             SOFTWARE_NODE("endpoint@0", swnodes->ports[port_index].ep_props,
> > +                           &swnodes->nodes[ACPI_DEVICE_SWNODE_PORT(port_index)]);
> > +
> > +     if (port->crs_csi2_local)
> > +             init_csi2_port_local(adev, port, port_fwnode, ep_prop_index);
> > +}
> > +
> > +#define MIPI_IMG_PORT_PREFIX "mipi-img-port-"
> > +
> > +static struct fwnode_handle *get_mipi_port_handle(struct fwnode_handle *adev_fwnode,
> > +                                               unsigned int port_nr)
> > +{
> > +     char port_name[sizeof(MIPI_IMG_PORT_PREFIX) + 2];
> > +
> > +     if (snprintf(port_name, sizeof(port_name), "%s%u",
> > +                  MIPI_IMG_PORT_PREFIX, port_nr) >= sizeof(port_name))
> > +             return NULL;
> > +
> > +     return fwnode_get_named_child_node(adev_fwnode, port_name);
> > +}
> > +
> > +static void init_crs_csi2_swnodes(struct crs_csi2 *csi2)
> > +{
> > +     struct acpi_buffer buffer = { .length = ACPI_ALLOCATE_BUFFER };
> > +     struct acpi_device_software_nodes *swnodes = csi2->swnodes;
> > +     acpi_handle handle = csi2->handle;
> > +     struct fwnode_handle *adev_fwnode;
> > +     struct acpi_device *adev;
> > +     acpi_status status;
> > +     unsigned int i;
> > +     int ret;
> > +
> > +     /*
> > +      * Bail out if the swnodes are not available (either they have not been
> > +      * allocated or they have been assigned to the device already).
> > +      */
> > +     if (!swnodes)
> > +             return;
> > +
> > +     adev = acpi_fetch_acpi_dev(handle);
> > +     if (!adev)
> > +             return;
> > +
> > +     adev_fwnode = acpi_fwnode_handle(adev);
> > +
> > +     status = acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
> > +     if (ACPI_FAILURE(status)) {
> > +             acpi_handle_info(handle, "Unable to get the path name\n");
> > +             return;
> > +     }
> > +
> > +     swnodes->nodes[ACPI_DEVICE_SWNODE_ROOT] =
> > +                     SOFTWARE_NODE(buffer.pointer, swnodes->dev_props, NULL);
> > +
> > +     for (i = 0; i < swnodes->num_ports; i++) {
> > +             struct acpi_device_software_node_port *port = &swnodes->ports[i];
> > +             struct fwnode_handle *port_fwnode;
> > +
> > +             /*
> > +              * The MIPI DisCo for Imaging specification defines _DSD device
> > +              * properties for providing CSI-2 port parameters that can be
> > +              * accessed through the generic device properties framework.  To
> > +              * access them, it is first necessary to find the data node
> > +              * representing the port under the given ACPI device object.
> > +              */
> > +             port_fwnode = get_mipi_port_handle(adev_fwnode, port->port_nr);
> > +             if (!port_fwnode) {
> > +                     acpi_handle_info(handle,
> > +                                      "MIPI port name too long for port %u\n",
> > +                                      port->port_nr);
> > +                     continue;
> > +             }
> > +
> > +             init_csi2_port(adev, swnodes, port, port_fwnode, i);
> > +
> > +             fwnode_handle_put(port_fwnode);
> > +     }
> > +
> > +     ret = software_node_register_node_group(swnodes->nodeptrs);
> > +     if (ret < 0) {
> > +             acpi_handle_info(handle,
> > +                              "Unable to register software nodes (%d)\n", ret);
> > +             return;
> > +     }
> > +
> > +     adev->swnodes = swnodes;
> > +     adev_fwnode->secondary = software_node_fwnode(swnodes->nodes);
> > +
> > +     /*
> > +      * Prevents the swnodes from this csi2 entry from being assigned again
> > +      * or freed prematurely.
> > +      */
> > +     csi2->swnodes = NULL;
> > +}
> > +
> > +/**
> > + * acpi_mipi_init_crs_csi2_swnodes - Initialize _CRS CSI-2 software nodes
> > + *
> > + * Use MIPI DiSco for Imaging device properties to finalize the initialization
> > + * of CSI-2 software nodes for all ACPI device objects that have been already
> > + * enumerated.
> > + */
> > +void acpi_mipi_init_crs_csi2_swnodes(void)
> > +{
> > +     struct crs_csi2 *csi2, *csi2_tmp;
> > +
> > +     list_for_each_entry_safe(csi2, csi2_tmp, &acpi_mipi_crs_csi2_list, entry)
> > +             init_crs_csi2_swnodes(csi2);
> > +}
> > +
> >  /**
> >   * acpi_mipi_crs_csi2_cleanup - Free _CRS CSI-2 temporary data
> >   */
> > Index: linux-pm/drivers/acpi/internal.h
> > ===================================================================
> > --- linux-pm.orig/drivers/acpi/internal.h
> > +++ linux-pm/drivers/acpi/internal.h
> > @@ -287,6 +287,7 @@ static inline void acpi_init_lpit(void)
> >
> >  void acpi_mipi_check_crs_csi2(acpi_handle handle);
> >  void acpi_mipi_scan_crs_csi2(void);
> > +void acpi_mipi_init_crs_csi2_swnodes(void);
> >  void acpi_mipi_crs_csi2_cleanup(void);
> >
> >  #endif /* _ACPI_INTERNAL_H_ */
> > Index: linux-pm/drivers/acpi/scan.c
> > ===================================================================
> > --- linux-pm.orig/drivers/acpi/scan.c
> > +++ linux-pm/drivers/acpi/scan.c
> > @@ -2447,6 +2447,13 @@ static void acpi_scan_postponed_branch(a
> >
> >       acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
> >                           acpi_bus_check_add_2, NULL, NULL, (void **)&adev);
> > +
> > +     /*
> > +      * Populate the ACPI _CRS CSI-2 software nodes for the ACPI devices that
> > +      * have been added above.
> > +      */
> > +     acpi_mipi_init_crs_csi2_swnodes();
> > +
> >       acpi_bus_attach(adev, NULL);
> >  }
> >
> > @@ -2516,11 +2523,12 @@ int acpi_bus_scan(acpi_handle handle)
> >               return -ENODEV;
> >
> >       /*
> > -      * Allocate ACPI _CRS CSI-2 software nodes using information extracted
> > +      * Set up ACPI _CRS CSI-2 software nodes using information extracted
> >        * from the _CRS CSI-2 resource descriptors during the ACPI namespace
> > -      * walk above.
> > +      * walk above and MIPI DiSco for Imaging device properties.
> >        */
> >       acpi_mipi_scan_crs_csi2();
> > +     acpi_mipi_init_crs_csi2_swnodes();
> >
> >       acpi_bus_attach(device, (void *)true);
> >
> > Index: linux-pm/include/acpi/acpi_bus.h
> > ===================================================================
> > --- linux-pm.orig/include/acpi/acpi_bus.h
> > +++ linux-pm/include/acpi/acpi_bus.h
> > @@ -366,10 +366,17 @@ struct acpi_device_data {
> >
> >  struct acpi_gpio_mapping;
> >
> > +#define ACPI_DEVICE_SWNODE_ROOT                      0
> > +
> >  #define ACPI_DEVICE_CSI2_DATA_LANES          4
> >
> >  #define ACPI_DEVICE_SWNODE_PORT_NAME_LENGTH  8
> >
> > +enum acpi_device_swnode_dev_props {
> > +     ACPI_DEVICE_SWNODE_DEV_NUM_OF,
> > +     ACPI_DEVICE_SWNODE_DEV_NUM_ENTRIES
> > +};
> > +
> >  enum acpi_device_swnode_port_props {
> >       ACPI_DEVICE_SWNODE_PORT_REG,
> >       ACPI_DEVICE_SWNODE_PORT_NUM_OF,
> > @@ -425,12 +432,14 @@ struct acpi_device_software_node_port {
> >
> >  /**
> >   * struct acpi_device_software_nodes - Software nodes for an ACPI device
> > + * @dev_props: Device properties.
> >   * @nodes: Software nodes for root as well as ports and endpoints.
> >   * @nodeprts: Array of software node pointers, for (un)registering them.
> >   * @ports: Information related to each port and endpoint within a port.
> >   * @num_ports: The number of ports.
> >   */
> >  struct acpi_device_software_nodes {
> > +     struct property_entry dev_props[ACPI_DEVICE_SWNODE_DEV_NUM_ENTRIES];
> >       struct software_node *nodes;
> >       const struct software_node **nodeptrs;
> >       struct acpi_device_software_node_port *ports;
> > @@ -455,6 +464,7 @@ struct acpi_device {
> >       struct acpi_device_data data;
> >       struct acpi_scan_handler *handler;
> >       struct acpi_hotplug_context *hp;
> > +     struct acpi_device_software_nodes *swnodes;
> >       const struct acpi_gpio_mapping *driver_gpios;
> >       void *driver_data;
> >       struct device dev;
> >
> >
> >
>
> --
> Regards,
>
> Sakari Ailus
>

Re: [PATCH v2 5/6] ACPI: scan: Extract MIPI DiSco for Imaging data into swnodes

[Sakari Ailus]

Hi Rafael,

On Tue, Oct 31, 2023 at 02:46:51PM +0100, Rafael J. Wysocki wrote:
> Hi Sakari,
> 
> On Tue, Oct 31, 2023 at 11:33 AM Sakari Ailus
> <sakari.ailus@linux.intel.com> wrote:
> >
> > Hi Rafael,
> >
> > On subject:
> >
> > s/DiSco/DisCo/
> 
> Huh
> 
> Thanks for catching this!
> 
> > On Fri, Oct 20, 2023 at 04:39:27PM +0200, Rafael J. Wysocki wrote:
> > > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > >
> > > Add information extracted from the MIPI DiSco for Imaging device
> >
> > Ditto.
> >
> > > properties to software nodes created during the CSI-2 connection graph
> > > discovery.
> > >
> > > Link: https://www.mipi.org/specifications/mipi-di
> >
> > This URL is broken. The correct URL is:
> >
> >         https://www.mipi.org/specifications/mipi-disco-imaging
> 
> OK
> 
> > > Co-developed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> > > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > > ---
> > >  drivers/acpi/internal.h |    1
> > >  drivers/acpi/mipi-di.c  |  240 +++++++++++++++++++++++++++++++++++++++++++++++-
> >
> > How about mipi-disco.c? I wouldn't mind having mipi-disco-imaging.c either.
> 
> Well, mipi-disco-imaging is a bit too long and the meaning of
> mipi-disco would not be clear IMO.
> 
> What about mipi-disco-img?

Seems fine to me.

> 
> [cut]
> 
> > > +     ret = fwnode_property_count_u8(port_fwnode, "mipi-img-lane-polarities");
> > > +     if (ret > 0) {
> > > +             unsigned long mask;
> > > +             unsigned int i;
> > > +
> > > +             /*
> > > +              * Total number of lanes here is clock lane + data lanes.
> > > +              * Require that number to be low enough so they all can be
> > > +              * covered by the bits in one byte.
> > > +              */
> > > +             BUILD_BUG_ON(BITS_PER_TYPE(u8) <= ARRAY_SIZE(port->data_lanes));
> > > +
> > > +             fwnode_property_read_u8_array(port_fwnode,
> > > +                                           "mipi-img-lane-polarities",
> > > +                                           val, 1);
> > > +
> > > +             for (mask = val[0], i = 0; i < num_lanes + 1; i++)
> > > +                     port->lane_polarities[i] = test_bit(i, &mask);
> >
> > This works only up to seven lanes.
> 
> True, but then ACPI_DEVICE_CSI2_DATA_LANES is defined as 4.

The spec has no limit and in practice 4 is relatively common while 8 exists
(but is somewhat rare). I actually think it'd be a good idea to bump this
to 8 already.

-- 
Regards,

Sakari Ailus

Re: [PATCH v2 5/6] ACPI: scan: Extract MIPI DiSco for Imaging data into swnodes

[Rafael J. Wysocki]

Hi Sakari,

On Tue, Oct 31, 2023 at 3:00 PM Sakari Ailus
<sakari.ailus@linux.intel.com> wrote:
>
> Hi Rafael,
>
> On Tue, Oct 31, 2023 at 02:46:51PM +0100, Rafael J. Wysocki wrote:
> > Hi Sakari,
> >
> > On Tue, Oct 31, 2023 at 11:33 AM Sakari Ailus
> > <sakari.ailus@linux.intel.com> wrote:
> > >
> > > Hi Rafael,
> > >
> > > On subject:
> > >
> > > s/DiSco/DisCo/
> >
> > Huh
> >
> > Thanks for catching this!
> >
> > > On Fri, Oct 20, 2023 at 04:39:27PM +0200, Rafael J. Wysocki wrote:
> > > > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > > >
> > > > Add information extracted from the MIPI DiSco for Imaging device
> > >
> > > Ditto.
> > >
> > > > properties to software nodes created during the CSI-2 connection graph
> > > > discovery.
> > > >
> > > > Link: https://www.mipi.org/specifications/mipi-di
> > >
> > > This URL is broken. The correct URL is:
> > >
> > >         https://www.mipi.org/specifications/mipi-disco-imaging
> >
> > OK
> >
> > > > Co-developed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> > > > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> > > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > > > ---
> > > >  drivers/acpi/internal.h |    1
> > > >  drivers/acpi/mipi-di.c  |  240 +++++++++++++++++++++++++++++++++++++++++++++++-
> > >
> > > How about mipi-disco.c? I wouldn't mind having mipi-disco-imaging.c either.
> >
> > Well, mipi-disco-imaging is a bit too long and the meaning of
> > mipi-disco would not be clear IMO.
> >
> > What about mipi-disco-img?
>
> Seems fine to me.
>
> >
> > [cut]
> >
> > > > +     ret = fwnode_property_count_u8(port_fwnode, "mipi-img-lane-polarities");
> > > > +     if (ret > 0) {
> > > > +             unsigned long mask;
> > > > +             unsigned int i;
> > > > +
> > > > +             /*
> > > > +              * Total number of lanes here is clock lane + data lanes.
> > > > +              * Require that number to be low enough so they all can be
> > > > +              * covered by the bits in one byte.
> > > > +              */
> > > > +             BUILD_BUG_ON(BITS_PER_TYPE(u8) <= ARRAY_SIZE(port->data_lanes));
> > > > +
> > > > +             fwnode_property_read_u8_array(port_fwnode,
> > > > +                                           "mipi-img-lane-polarities",
> > > > +                                           val, 1);
> > > > +
> > > > +             for (mask = val[0], i = 0; i < num_lanes + 1; i++)
> > > > +                     port->lane_polarities[i] = test_bit(i, &mask);
> > >
> > > This works only up to seven lanes.
> >
> > True, but then ACPI_DEVICE_CSI2_DATA_LANES is defined as 4.
>
> The spec has no limit and in practice 4 is relatively common while 8 exists
> (but is somewhat rare). I actually think it'd be a good idea to bump this
> to 8 already.

OK