[PATCH 2/8] ACPI: property: Parse _CRS CSI-2 descriptor

Sakari Ailus
2023-01-17T12:22:23Z

Parse newly added ACPI _CRS CSI-2 descriptor for CSI-2 and camera
configuration. For now, only figure out where the descriptor is present in
order to allow adding information from it to related devices.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
drivers/acpi/Makefile | 2 +-
drivers/acpi/internal.h | 7 +
drivers/acpi/mipi.c | 318 ++++++++++++++++++++++++++++++++++++++++
drivers/acpi/scan.c | 16 +-
include/acpi/acpi_bus.h | 11 ++
5 files changed, 349 insertions(+), 5 deletions(-)
create mode 100644 drivers/acpi/mipi.c

diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index a5b649e71ab1b..a98fa1bc15548 100644
--- a/drivers/acpi/Makefile
+++ b/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.o
acpi-y += resource.o
acpi-y += acpi_processor.o
acpi-y += processor_core.o
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index ec584442fb298..1ec4aa92bf17a 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -282,4 +282,11 @@ void acpi_init_lpit(void);
static inline void acpi_init_lpit(void) { }
#endif

+/*--------------------------------------------------------------------------
+ ACPI and MIPI DisCo for Imaging conversion
+ -------------------------------------------------------------------------- */
+
+void acpi_crs_csi2_swnodes_del_free(void);
+void acpi_bus_scan_crs_csi2(acpi_handle handle);
+
#endif /* _ACPI_INTERNAL_H_ */
diff --git a/drivers/acpi/mipi.c b/drivers/acpi/mipi.c
new file mode 100644
index 0000000000000..9701266bf5c67
--- /dev/null
+++ b/drivers/acpi/mipi.c
@@ -0,0 +1,318 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * MIPI DisCo for Imaging support.
+ *
+ * Copyright (C) 2022 Intel Corporation
+ */
+
+#include <linux/acpi.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/overflow.h>
+#include <linux/slab.h>
+#include <linux/sort.h>
+
+#include "internal.h"
+
+struct crs_csi2_swnodes {
+ struct list_head list;
+ acpi_handle handle;
+ struct acpi_device_software_nodes *ads;
+};
+
+static LIST_HEAD(crs_csi2_swnodes);
+
+static void crs_csi2_swnode_del_free(struct crs_csi2_swnodes *swnodes)
+{
+ list_del(&swnodes->list);
+ kfree(swnodes);
+}
+
+void acpi_crs_csi2_swnodes_del_free(void)
+{
+ struct crs_csi2_swnodes *swnodes, *swnodes_tmp;
+
+ list_for_each_entry_safe(swnodes, swnodes_tmp, &crs_csi2_swnodes, list)
+ crs_csi2_swnode_del_free(swnodes);
+}
+
+struct crs_csi2_instance {
+ struct list_head list;
+ struct acpi_resource_csi2_serialbus csi2;
+ acpi_handle remote_handle;
+ char remote_name[];
+};
+
+struct crs_csi2 {
+ struct list_head list;
+ acpi_handle handle;
+ struct list_head buses;
+};
+
+struct scan_check_crs_csi2_context {
+ struct list_head res_list;
+ acpi_handle handle;
+};
+
+static acpi_status scan_check_crs_csi2_instance(struct acpi_resource *res,
+ void *context)
+{
+ struct scan_check_crs_csi2_context *inst_context = context;
+ struct acpi_resource_csi2_serialbus *csi2;
+ struct crs_csi2_instance *inst;
+ acpi_handle remote_handle;
+ acpi_status status;
+
+ if (res->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
+ return AE_OK;
+
+ csi2 = &res->data.csi2_serial_bus;
+
+ if (csi2->type != ACPI_RESOURCE_SERIAL_TYPE_CSI2)
+ return AE_OK;
+
+ if (!csi2->resource_source.string_length) {
+ acpi_handle_debug(inst_context->handle,
+ "invalid resource source string length\n");
+ return AE_OK;
+ }
+
+ status = acpi_get_handle(NULL, csi2->resource_source.string_ptr,
+ &remote_handle);
+ if (status != AE_OK) {
+ acpi_handle_warn(inst_context->handle,
+ "cannot get handle for %s\n",
+ csi2->resource_source.string_ptr);
+ return AE_OK;
+ }
+
+ inst = kmalloc(struct_size(inst, remote_name,
+ csi2->resource_source.string_length),
+ GFP_KERNEL);
+ if (!inst)
+ return AE_OK;
+
+ inst->csi2 = *csi2;
+ memcpy(inst->remote_name, csi2->resource_source.string_ptr,
+ csi2->resource_source.string_length);
+ inst->csi2.resource_source.string_ptr = inst->remote_name;
+ inst->remote_handle = remote_handle;
+
+ list_add(&inst->list, &inst_context->res_list);
+
+ return AE_OK;
+}
+
+static acpi_status scan_check_crs_csi2(acpi_handle handle, u32 nesting_level,
+ void *context, void **ret)
+{
+ struct scan_check_crs_csi2_context inst_context = {
+ .handle = handle,
+ .res_list = LIST_HEAD_INIT(inst_context.res_list),
+ };
+ struct list_head *list = context;
+ struct crs_csi2 *csi2;
+
+ INIT_LIST_HEAD(&inst_context.res_list);
+
+ acpi_walk_resources(handle, METHOD_NAME__CRS,
+ scan_check_crs_csi2_instance, &inst_context);
+
+ if (list_empty(&inst_context.res_list))
+ return AE_OK;
+
+ csi2 = kmalloc(sizeof(*csi2), GFP_KERNEL);
+ if (!csi2)
+ return AE_OK;
+
+ csi2->handle = handle;
+ list_replace(&inst_context.res_list, &csi2->buses);
+ list_add(&csi2->list, list);
+
+ return AE_OK;
+}
+
+struct acpi_handle_ref {
+ acpi_handle handle;
+ unsigned int count;
+};
+
+#define NO_CSI2_PORT (~1U)
+
+static int crs_handle_cmp(const void *__a, const void *__b)
+{
+ const struct acpi_handle_ref *a = __a, *b = __b;
+
+ return a->handle < b->handle ? -1 : a->handle > b->handle;
+}
+
+static void crs_csi2_release(struct list_head *crs_csi2_handles)
+{
+ struct crs_csi2 *csi2, *csi2_tmp;
+
+ list_for_each_entry_safe(csi2, csi2_tmp, crs_csi2_handles, list) {
+ struct crs_csi2_instance *inst, *inst_tmp;
+
+ list_for_each_entry_safe(inst, inst_tmp, &csi2->buses, list) {
+ list_del(&inst->list);
+ kfree(inst);
+ }
+
+ list_del(&csi2->list);
+ kfree(csi2);
+ }
+}
+
+/**
+ * acpi_bus_scan_crs_csi2 - Scan a device and its child devices for _CRS CSI-2
+ *
+ * @handle: ACPI handle to scan
+ *
+ * This function does a number of things:
+ *
+ * 1. Scan an ACPI device and its children for _CRS CSI-2 instances. The
+ * instances are stored for later use.
+ *
+ * 2. Count how many references to other devices _CRS CSI-2 instances have in
+ * total.
+ *
+ * 3. Count the number of references to other devices for each _CRS CSI-2
+ * instance.
+ *
+ * 4. Allocate memory for swnodes each ACPI device requires later on, and
+ * generate a list of such allocations.
+ *
+ * Note that struct acpi_device isn't available yet at this time.
+ *
+ * acpi_scan_lock in scan.c must be held when calling this function.
+ */
+void acpi_bus_scan_crs_csi2(acpi_handle handle)
+{
+ struct acpi_handle_ref *handle_refs;
+ struct acpi_handle_ref *this = NULL;
+ LIST_HEAD(crs_csi2_handles);
+ unsigned int handle_count = 0, this_count;
+ unsigned int curr = 0;
+ struct crs_csi2 *csi2;
+
+ /* Collect the devices that have a _CRS CSI-2 resource */
+ acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, ACPI_UINT32_MAX,
+ scan_check_crs_csi2, NULL, &crs_csi2_handles, NULL);
+
+ /*
+ * Figure out how much temporary storage we need for counting
+ * connections in each device.
+ */
+ list_for_each_entry(csi2, &crs_csi2_handles, list) {
+ struct crs_csi2_instance *inst;
+
+ handle_count++;
+
+ list_for_each_entry(inst, &csi2->buses, list)
+ handle_count++;
+ }
+
+ /* No handles? Bail out here. */
+ if (!handle_count)
+ return;
+
+ handle_refs = kcalloc(handle_count + 1, sizeof(*handle_refs),
+ GFP_KERNEL);
+ if (!handle_refs) {
+ acpi_handle_debug(handle, "no memory for %u handle refs\n",
+ handle_count + 1);
+ return;
+ }
+
+ /* Associate handles to the number of references. */
+ list_for_each_entry(csi2, &crs_csi2_handles, list) {
+ struct crs_csi2_instance *inst;
+ struct acpi_handle_ref *handle_ref;
+
+ handle_ref = &handle_refs[curr++];
+ handle_ref->handle = csi2->handle;
+
+ list_for_each_entry(inst, &csi2->buses, list) {
+ handle_refs[curr].handle = inst->remote_handle;
+ handle_refs[curr].count = 1;
+ handle_ref->count++;
+ curr++;
+ }
+ }
+
+ handle_refs[curr].handle = NULL;
+
+ sort(handle_refs, handle_count, sizeof(*handle_refs), crs_handle_cmp,
+ NULL);
+
+ /*
+ * Finally count references in each handle, allocate space for device
+ * specific ports, properties and fill the _CRS CSI2 descriptor
+ * originated data.
+ */
+ this = handle_refs;
+ this_count = this->count;
+ for (curr = 1; curr < handle_count + 1; curr++) {
+ struct acpi_device_software_nodes *ads;
+ struct crs_csi2_swnodes *swnodes;
+ size_t alloc_size;
+ void *end;
+
+ if (this->handle == handle_refs[curr].handle) {
+ this_count += handle_refs[curr].count;
+ continue;
+ }
+
+ /*
+ * Allocate memory for ports, node pointers (number of nodes +
+ * 1 (guardian), nodes (root + number of ports * 2 (for for
+ * every port there is an endpoint)).
+ */
+ if (check_mul_overflow(sizeof(*ads->ports) +
+ sizeof(*ads->nodes) * 2 +
+ sizeof(*ads->nodeptrs) * 2,
+ (size_t)this_count, &alloc_size) ||
+ check_add_overflow(sizeof(*ads) + sizeof(*ads->nodes) +
+ sizeof(*ads->nodeptrs) * 2,
+ alloc_size, &alloc_size)) {
+ acpi_handle_warn(handle, "too many handles (%u)",
+ this_count);
+ continue;
+ }
+
+ swnodes = kzalloc(sizeof(*swnodes), GFP_KERNEL);
+ ads = kzalloc(alloc_size, GFP_KERNEL);
+ ads->ports = (void *)(ads + 1);
+ ads->nodes = (void *)(ads->ports + this_count);
+ ads->nodeptrs = (void *)(ads->nodes +
+ this_count * 2 + 1);
+ end = ads->nodeptrs + this_count * 2 + 2;
+ if (!swnodes || !ads ||
+ WARN_ON((void *)ads + alloc_size != end)) {
+ kfree(swnodes);
+ kfree(ads);
+ acpi_handle_debug(handle,
+ "cannot allocate for %u swnodes\n",
+ this_count);
+ } else {
+ unsigned int i;
+
+ ads->num_ports = this_count;
+ for (i = 0; i < this_count * 2 + 1; i++)
+ ads->nodeptrs[i] = &ads->nodes[i];
+ ads->nodeptrs[i] = NULL;
+ for (i = 0; i < this_count; i++)
+ ads->ports[i].port_nr = NO_CSI2_PORT;
+ swnodes->handle = this->handle;
+ swnodes->ads = ads;
+ list_add(&swnodes->list, &crs_csi2_swnodes);
+ }
+
+ this = &handle_refs[curr];
+ this_count = this->count;
+ }
+
+ kfree(handle_refs);
+
+ crs_csi2_release(&crs_csi2_handles);
+}
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 0c6f06abe3f47..50de874b8f208 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -2423,9 +2423,12 @@ EXPORT_SYMBOL_GPL(acpi_dev_get_next_consumer_dev);
int acpi_bus_scan(acpi_handle handle)
{
struct acpi_device *device = NULL;
+ int ret = 0;

acpi_bus_scan_second_pass = false;

+ acpi_bus_scan_crs_csi2(handle);
+
/* Pass 1: Avoid enumerating devices with missing dependencies. */

if (ACPI_SUCCESS(acpi_bus_check_add(handle, true, &device)))
@@ -2433,13 +2436,15 @@ int acpi_bus_scan(acpi_handle handle)
acpi_bus_check_add_1, NULL, NULL,
(void **)&device);

- if (!device)
- return -ENODEV;
+ if (!device) {
+ ret = -ENODEV;
+ goto out_release;
+ }

acpi_bus_attach(device, (void *)true);

if (!acpi_bus_scan_second_pass)
- return 0;
+ goto out_release;

/* Pass 2: Enumerate all of the remaining devices. */

@@ -2452,7 +2457,10 @@ int acpi_bus_scan(acpi_handle handle)

acpi_bus_attach(device, NULL);

- return 0;
+out_release:
+ acpi_crs_csi2_swnodes_del_free();
+
+ return ret;
}
EXPORT_SYMBOL(acpi_bus_scan);

diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index e44be31115a67..a05fe22c1175c 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -360,6 +360,17 @@ struct acpi_device_data {

struct acpi_gpio_mapping;

+struct acpi_device_software_node_port {
+ unsigned int port_nr;
+};
+
+struct acpi_device_software_nodes {
+ struct acpi_device_software_node_port *ports;
+ struct software_node *nodes;
+ const struct software_node **nodeptrs;
+ unsigned int num_ports;
+};
+
/* Device */
struct acpi_device {
u32 pld_crc;
--
2.30.2