diff options
Diffstat (limited to 'drivers/platform/surface/surface_aggregator_registry.c')
| -rw-r--r-- | drivers/platform/surface/surface_aggregator_registry.c | 284 |
1 files changed, 284 insertions, 0 deletions
diff --git a/drivers/platform/surface/surface_aggregator_registry.c b/drivers/platform/surface/surface_aggregator_registry.c new file mode 100644 index 000000000000..a051d941ad96 --- /dev/null +++ b/drivers/platform/surface/surface_aggregator_registry.c @@ -0,0 +1,284 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Surface System Aggregator Module (SSAM) client device registry. + * + * Registry for non-platform/non-ACPI SSAM client devices, i.e. devices that + * cannot be auto-detected. Provides device-hubs and performs instantiation + * for these devices. + * + * Copyright (C) 2020-2021 Maximilian Luz <luzmaximilian@gmail.com> + */ + +#include <linux/acpi.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/property.h> + +#include <linux/surface_aggregator/controller.h> +#include <linux/surface_aggregator/device.h> + + +/* -- Device registry. ------------------------------------------------------ */ + +/* + * SSAM device names follow the SSAM module alias, meaning they are prefixed + * with 'ssam:', followed by domain, category, target ID, instance ID, and + * function, each encoded as two-digit hexadecimal, separated by ':'. In other + * words, it follows the scheme + * + * ssam:dd:cc:tt:ii:ff + * + * Where, 'dd', 'cc', 'tt', 'ii', and 'ff' are the two-digit hexadecimal + * values mentioned above, respectively. + */ + +/* Root node. */ +static const struct software_node ssam_node_root = { + .name = "ssam_platform_hub", +}; + +/* Devices for Surface Book 2. */ +static const struct software_node *ssam_node_group_sb2[] = { + &ssam_node_root, + NULL, +}; + +/* Devices for Surface Book 3. */ +static const struct software_node *ssam_node_group_sb3[] = { + &ssam_node_root, + NULL, +}; + +/* Devices for Surface Laptop 1. */ +static const struct software_node *ssam_node_group_sl1[] = { + &ssam_node_root, + NULL, +}; + +/* Devices for Surface Laptop 2. */ +static const struct software_node *ssam_node_group_sl2[] = { + &ssam_node_root, + NULL, +}; + +/* Devices for Surface Laptop 3. */ +static const struct software_node *ssam_node_group_sl3[] = { + &ssam_node_root, + NULL, +}; + +/* Devices for Surface Laptop Go. */ +static const struct software_node *ssam_node_group_slg1[] = { + &ssam_node_root, + NULL, +}; + +/* Devices for Surface Pro 5. */ +static const struct software_node *ssam_node_group_sp5[] = { + &ssam_node_root, + NULL, +}; + +/* Devices for Surface Pro 6. */ +static const struct software_node *ssam_node_group_sp6[] = { + &ssam_node_root, + NULL, +}; + +/* Devices for Surface Pro 7. */ +static const struct software_node *ssam_node_group_sp7[] = { + &ssam_node_root, + NULL, +}; + + +/* -- Device registry helper functions. ------------------------------------- */ + +static int ssam_uid_from_string(const char *str, struct ssam_device_uid *uid) +{ + u8 d, tc, tid, iid, fn; + int n; + + n = sscanf(str, "ssam:%hhx:%hhx:%hhx:%hhx:%hhx", &d, &tc, &tid, &iid, &fn); + if (n != 5) + return -EINVAL; + + uid->domain = d; + uid->category = tc; + uid->target = tid; + uid->instance = iid; + uid->function = fn; + + return 0; +} + +static int ssam_hub_remove_devices_fn(struct device *dev, void *data) +{ + if (!is_ssam_device(dev)) + return 0; + + ssam_device_remove(to_ssam_device(dev)); + return 0; +} + +static void ssam_hub_remove_devices(struct device *parent) +{ + device_for_each_child_reverse(parent, NULL, ssam_hub_remove_devices_fn); +} + +static int ssam_hub_add_device(struct device *parent, struct ssam_controller *ctrl, + struct fwnode_handle *node) +{ + struct ssam_device_uid uid; + struct ssam_device *sdev; + int status; + + status = ssam_uid_from_string(fwnode_get_name(node), &uid); + if (status) + return status; + + sdev = ssam_device_alloc(ctrl, uid); + if (!sdev) + return -ENOMEM; + + sdev->dev.parent = parent; + sdev->dev.fwnode = node; + + status = ssam_device_add(sdev); + if (status) + ssam_device_put(sdev); + + return status; +} + +static int ssam_hub_add_devices(struct device *parent, struct ssam_controller *ctrl, + struct fwnode_handle *node) +{ + struct fwnode_handle *child; + int status; + + fwnode_for_each_child_node(node, child) { + /* + * Try to add the device specified in the firmware node. If + * this fails with -EINVAL, the node does not specify any SSAM + * device, so ignore it and continue with the next one. + */ + + status = ssam_hub_add_device(parent, ctrl, child); + if (status && status != -EINVAL) + goto err; + } + + return 0; +err: + ssam_hub_remove_devices(parent); + return status; +} + + +/* -- SSAM platform/meta-hub driver. ---------------------------------------- */ + +static const struct acpi_device_id ssam_platform_hub_match[] = { + /* Surface Pro 4, 5, and 6 (OMBR < 0x10) */ + { "MSHW0081", (unsigned long)ssam_node_group_sp5 }, + + /* Surface Pro 6 (OMBR >= 0x10) */ + { "MSHW0111", (unsigned long)ssam_node_group_sp6 }, + + /* Surface Pro 7 */ + { "MSHW0116", (unsigned long)ssam_node_group_sp7 }, + + /* Surface Book 2 */ + { "MSHW0107", (unsigned long)ssam_node_group_sb2 }, + + /* Surface Book 3 */ + { "MSHW0117", (unsigned long)ssam_node_group_sb3 }, + + /* Surface Laptop 1 */ + { "MSHW0086", (unsigned long)ssam_node_group_sl1 }, + + /* Surface Laptop 2 */ + { "MSHW0112", (unsigned long)ssam_node_group_sl2 }, + + /* Surface Laptop 3 (13", Intel) */ + { "MSHW0114", (unsigned long)ssam_node_group_sl3 }, + + /* Surface Laptop 3 (15", AMD) */ + { "MSHW0110", (unsigned long)ssam_node_group_sl3 }, + + /* Surface Laptop Go 1 */ + { "MSHW0118", (unsigned long)ssam_node_group_slg1 }, + + { }, +}; +MODULE_DEVICE_TABLE(acpi, ssam_platform_hub_match); + +static int ssam_platform_hub_probe(struct platform_device *pdev) +{ + const struct software_node **nodes; + struct ssam_controller *ctrl; + struct fwnode_handle *root; + int status; + + nodes = (const struct software_node **)acpi_device_get_match_data(&pdev->dev); + if (!nodes) + return -ENODEV; + + /* + * As we're adding the SSAM client devices as children under this device + * and not the SSAM controller, we need to add a device link to the + * controller to ensure that we remove all of our devices before the + * controller is removed. This also guarantees proper ordering for + * suspend/resume of the devices on this hub. + */ + ctrl = ssam_client_bind(&pdev->dev); + if (IS_ERR(ctrl)) + return PTR_ERR(ctrl) == -ENODEV ? -EPROBE_DEFER : PTR_ERR(ctrl); + + status = software_node_register_node_group(nodes); + if (status) + return status; + + root = software_node_fwnode(&ssam_node_root); + if (!root) { + software_node_unregister_node_group(nodes); + return -ENOENT; + } + + set_secondary_fwnode(&pdev->dev, root); + + status = ssam_hub_add_devices(&pdev->dev, ctrl, root); + if (status) { + set_secondary_fwnode(&pdev->dev, NULL); + software_node_unregister_node_group(nodes); + } + + platform_set_drvdata(pdev, nodes); + return status; +} + +static int ssam_platform_hub_remove(struct platform_device *pdev) +{ + const struct software_node **nodes = platform_get_drvdata(pdev); + + ssam_hub_remove_devices(&pdev->dev); + set_secondary_fwnode(&pdev->dev, NULL); + software_node_unregister_node_group(nodes); + return 0; +} + +static struct platform_driver ssam_platform_hub_driver = { + .probe = ssam_platform_hub_probe, + .remove = ssam_platform_hub_remove, + .driver = { + .name = "surface_aggregator_platform_hub", + .acpi_match_table = ssam_platform_hub_match, + .probe_type = PROBE_PREFER_ASYNCHRONOUS, + }, +}; +module_platform_driver(ssam_platform_hub_driver); + +MODULE_AUTHOR("Maximilian Luz <luzmaximilian@gmail.com>"); +MODULE_DESCRIPTION("Device-registry for Surface System Aggregator Module"); +MODULE_LICENSE("GPL"); |