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

Rafael J. Wysocki
2023-10-20T14:49:54Z

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);
}

/**