===================================================================
@@ -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-disco-imaging.o
acpi-y += resource.o
acpi-y += acpi_processor.o
acpi-y += processor_core.o
===================================================================
@@ -282,4 +282,12 @@ 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_ */
===================================================================
@@ -0,0 +1,305 @@
+// 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_res_walk_data {
+ acpi_handle handle;
+ struct list_head connections;
+};
+
+static acpi_status acpi_parse_csi2_resource(struct acpi_resource *res,
+ void *context)
+{
+ struct csi2_res_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)
+{
+ csi_csr2_release_connections(&csi2->connections);
+ list_del(&csi2->entry);
+ acpi_detach_data(csi2->handle, acpi_mipi_data_tag);
+ 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_res_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, acpi_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 bool alloc_crs_csi2_swnodes(struct crs_csi2 *csi2)
+{
+ acpi_handle handle = csi2->handle;
+ size_t port_count = csi2->port_count;
+ struct acpi_device_software_nodes *swnodes;
+ size_t alloc_size;
+ unsigned int i;
+ bool overflow;
+
+ /*
+ * 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)).
+ */
+ overflow = check_mul_overflow(sizeof(*swnodes->ports) +
+ sizeof(*swnodes->nodes) * 2 +
+ sizeof(*swnodes->nodeptrs) * 2,
+ port_count, &alloc_size);
+ overflow = overflow ||
+ check_add_overflow(sizeof(*swnodes) +
+ sizeof(*swnodes->nodes) +
+ sizeof(*swnodes->nodeptrs) * 2,
+ alloc_size, &alloc_size);
+ if (overflow) {
+ acpi_handle_info(handle,
+ "too many _CRS CSI-2 resource handles (%zu)",
+ port_count);
+ return false;
+ }
+
+ swnodes = kmalloc(alloc_size, GFP_KERNEL);
+ if (!swnodes)
+ return false;
+
+ 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 true;
+}
+
+/**
+ * acpi_mipi_scan_crs_csi2 - Allocate 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, *csi2_tmp;
+ 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;
+
+ 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_safe(csi2, csi2_tmp, &acpi_mipi_crs_csi2_list, entry) {
+ /*
+ * Drop the list entry on failure, because in that case it will
+ * not be used going forward anyway.
+ */
+ if (!alloc_crs_csi2_swnodes(csi2))
+ acpi_mipi_del_crs_csi2(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) {
+ kfree(csi2->swnodes);
+ acpi_mipi_del_crs_csi2(csi2);
+ }
+}
===================================================================
@@ -363,6 +363,17 @@ struct acpi_device_data {
struct acpi_gpio_mapping;
+struct acpi_device_software_node_port {
+ unsigned int port_nr;
+};
+
+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;
===================================================================
@@ -1970,7 +1970,7 @@ 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;
@@ -1983,8 +1983,7 @@ 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);
@@ -2029,7 +2028,14 @@ 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 not_used_1,
+ void *not_used_2, void **not_used_3)
+{
+ 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);
@@ -2047,9 +2053,25 @@ 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 */
@@ -2072,10 +2094,10 @@ 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;
@@ -2487,12 +2509,21 @@ 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);