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

Rafael J. Wysocki
2023-10-20T14:49:53Z

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;