From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Subject: [PATCH] ACPI: scan: Extract MIPI DisCo for Imaging data into swnodes 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-disco-imaging Co-developed-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> --- v2 -> v3: * Change the name of the new file to mipi-disco-img.c * "DiSco" -> "DisCo" in multiple places * Fix the link in the Link: tag * Change the number of data lanes limit and add a comment regarding it * Use ACPI_DEVICE_CSI2_DATA_LANES directly in several places instead of array sizes equal to it --- drivers/acpi/internal.h | 1 drivers/acpi/mipi-disco-img.c | 249 +++++++++++++++++++++++++++++++++++++++++- drivers/acpi/scan.c | 12 +- include/acpi/acpi_bus.h | 17 ++ 4 files changed, 275 insertions(+), 4 deletions(-) Index: linux-pm/drivers/acpi/mipi-disco-img.c =================================================================== --- linux-pm.orig/drivers/acpi/mipi-disco-img.c +++ linux-pm/drivers/acpi/mipi-disco-img.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> @@ -431,6 +435,247 @@ 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 > ACPI_DEVICE_CSI2_DATA_LANES) { + acpi_handle_info(handle, "Too many link frequencies: %u\n", + num_link_freqs); + num_link_freqs = ACPI_DEVICE_CSI2_DATA_LANES; + } + + 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[ACPI_DEVICE_CSI2_DATA_LANES]; + 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 > ACPI_DEVICE_CSI2_DATA_LANES) { + acpi_handle_info(handle, "Too many data lanes: %u\n", + num_lanes); + num_lanes = ACPI_DEVICE_CSI2_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 * BITS_PER_TYPE(u8) >= num_lanes + 1) { + unsigned long mask = 0; + int byte_count = ret; + unsigned int i; + + /* + * The total number of lanes is ACPI_DEVICE_CSI2_DATA_LANES + 1 + * (data lanes + clock lane). It is not expected to ever be + * greater than the number of bits in an unsigned long + * variable, but ensure that this is the case. + */ + BUILD_BUG_ON(BITS_PER_TYPE(unsigned long) <= ACPI_DEVICE_CSI2_DATA_LANES); + + if (byte_count > ACPI_DEVICE_CSI2_DATA_LANES) { + acpi_handle_info(handle, "Too many lane polarities: %d\n", + byte_count); + byte_count = ACPI_DEVICE_CSI2_DATA_LANES; + } + fwnode_property_read_u8_array(port_fwnode, "mipi-img-lane-polarities", + val, byte_count); + + for (i = 0; BITS_PER_TYPE(u8) * i <= num_lanes; i++) + mask |= (unsigned long)val[i] << BITS_PER_TYPE(u8) * i; + + for (i = 0; i <= num_lanes; 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, + num_lanes + 1); + } else { + acpi_handle_info(handle, "Lane polarity bytes missing\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 +366,24 @@ struct acpi_device_data { struct acpi_gpio_mapping; +#define ACPI_DEVICE_SWNODE_ROOT 0 + +/* + * The maximum expected number of CSI-2 data lanes. + * + * This number is not expected to ever have to be equal to or greater than the + * number of bits in an unsigned long variable, but if it needs to be increased + * above that limit, code will need to be adjusted accordingly. + */ #define ACPI_DEVICE_CSI2_DATA_LANES 8 #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 +439,14 @@ 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 +471,7 @@ 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;
