From: Maximilian Luz Date: Wed, 10 Mar 2021 22:53:29 +0000 (+0100) Subject: HID: surface-hid: Add support for legacy keyboard interface X-Git-Tag: v5.15~1228^2~3^2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=35a927f2848bd79586c6374ebb99e4207f3b0c7f;p=platform%2Fkernel%2Flinux-starfive.git HID: surface-hid: Add support for legacy keyboard interface Add support for the legacy keyboard (KBD/TC=0x08) HID transport layer of the Surface System Aggregator Module (SSAM) to the Surface HID driver. On Surface Laptops 1 and 2, this interface is used to connect the integrated keyboard. Note that this subsystem interface essentially provides a limited HID transport layer. In contrast to the generic HID interface (TC=0x15) used on newer Surface models, this interface only allows (as far as we know) for a single device to be connected and is otherwise severely limited in terms of support for feature- and output-reports. Specifically, only caps-lock-LED output-reports and a single read-only feature-report are supported. Signed-off-by: Maximilian Luz Signed-off-by: Jiri Kosina --- diff --git a/drivers/hid/surface-hid/Kconfig b/drivers/hid/surface-hid/Kconfig index 642c7f0..7ce9b5d 100644 --- a/drivers/hid/surface-hid/Kconfig +++ b/drivers/hid/surface-hid/Kconfig @@ -21,6 +21,20 @@ config SURFACE_HID integrated touchpad and keyboard, on 7th generation Microsoft Surface models. +config SURFACE_KBD + tristate "HID keyboard transport driver for Surface System Aggregator Module" + select SURFACE_HID_CORE + help + Driver to support HID keyboards on Surface Laptop 1 and 2 devices. + + This driver provides support for the HID transport protocol provided + by the Surface Aggregator Module (i.e. the embedded controller) on + Microsoft Surface Laptops 1 and 2. It is used to connect the + integrated keyboard on those devices. + + Say M or Y here, if you want support for the integrated keyboard on + Microsoft Surface Laptops 1 and 2. + endmenu config SURFACE_HID_CORE diff --git a/drivers/hid/surface-hid/Makefile b/drivers/hid/surface-hid/Makefile index 62fc046..4ae11cf 100644 --- a/drivers/hid/surface-hid/Makefile +++ b/drivers/hid/surface-hid/Makefile @@ -4,3 +4,4 @@ # obj-$(CONFIG_SURFACE_HID_CORE) += surface_hid_core.o obj-$(CONFIG_SURFACE_HID) += surface_hid.o +obj-$(CONFIG_SURFACE_KBD) += surface_kbd.o diff --git a/drivers/hid/surface-hid/surface_kbd.c b/drivers/hid/surface-hid/surface_kbd.c new file mode 100644 index 0000000..0635341 --- /dev/null +++ b/drivers/hid/surface-hid/surface_kbd.c @@ -0,0 +1,300 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Surface System Aggregator Module (SSAM) HID transport driver for the legacy + * keyboard interface (KBD/TC=0x08 subsystem). Provides support for the + * integrated HID keyboard on Surface Laptops 1 and 2. + * + * Copyright (C) 2019-2021 Maximilian Luz + */ + +#include +#include +#include +#include +#include +#include + +#include + +#include "surface_hid_core.h" + + +/* -- SAM interface (KBD). -------------------------------------------------- */ + +#define KBD_FEATURE_REPORT_SIZE 7 /* 6 + report ID */ + +enum surface_kbd_cid { + SURFACE_KBD_CID_GET_DESCRIPTOR = 0x00, + SURFACE_KBD_CID_SET_CAPSLOCK_LED = 0x01, + SURFACE_KBD_CID_EVT_INPUT_GENERIC = 0x03, + SURFACE_KBD_CID_EVT_INPUT_HOTKEYS = 0x04, + SURFACE_KBD_CID_GET_FEATURE_REPORT = 0x0b, +}; + +static int ssam_kbd_get_descriptor(struct surface_hid_device *shid, u8 entry, u8 *buf, size_t len) +{ + struct ssam_request rqst; + struct ssam_response rsp; + int status; + + rqst.target_category = shid->uid.category; + rqst.target_id = shid->uid.target; + rqst.command_id = SURFACE_KBD_CID_GET_DESCRIPTOR; + rqst.instance_id = shid->uid.instance; + rqst.flags = SSAM_REQUEST_HAS_RESPONSE; + rqst.length = sizeof(entry); + rqst.payload = &entry; + + rsp.capacity = len; + rsp.length = 0; + rsp.pointer = buf; + + status = ssam_retry(ssam_request_sync_onstack, shid->ctrl, &rqst, &rsp, sizeof(entry)); + if (status) + return status; + + if (rsp.length != len) { + dev_err(shid->dev, "invalid descriptor length: got %zu, expected, %zu\n", + rsp.length, len); + return -EPROTO; + } + + return 0; +} + +static int ssam_kbd_set_caps_led(struct surface_hid_device *shid, bool value) +{ + struct ssam_request rqst; + u8 value_u8 = value; + + rqst.target_category = shid->uid.category; + rqst.target_id = shid->uid.target; + rqst.command_id = SURFACE_KBD_CID_SET_CAPSLOCK_LED; + rqst.instance_id = shid->uid.instance; + rqst.flags = 0; + rqst.length = sizeof(value_u8); + rqst.payload = &value_u8; + + return ssam_retry(ssam_request_sync_onstack, shid->ctrl, &rqst, NULL, sizeof(value_u8)); +} + +static int ssam_kbd_get_feature_report(struct surface_hid_device *shid, u8 *buf, size_t len) +{ + struct ssam_request rqst; + struct ssam_response rsp; + u8 payload = 0; + int status; + + rqst.target_category = shid->uid.category; + rqst.target_id = shid->uid.target; + rqst.command_id = SURFACE_KBD_CID_GET_FEATURE_REPORT; + rqst.instance_id = shid->uid.instance; + rqst.flags = SSAM_REQUEST_HAS_RESPONSE; + rqst.length = sizeof(payload); + rqst.payload = &payload; + + rsp.capacity = len; + rsp.length = 0; + rsp.pointer = buf; + + status = ssam_retry(ssam_request_sync_onstack, shid->ctrl, &rqst, &rsp, sizeof(payload)); + if (status) + return status; + + if (rsp.length != len) { + dev_err(shid->dev, "invalid feature report length: got %zu, expected, %zu\n", + rsp.length, len); + return -EPROTO; + } + + return 0; +} + +static bool ssam_kbd_is_input_event(const struct ssam_event *event) +{ + if (event->command_id == SURFACE_KBD_CID_EVT_INPUT_GENERIC) + return true; + + if (event->command_id == SURFACE_KBD_CID_EVT_INPUT_HOTKEYS) + return true; + + return false; +} + +static u32 ssam_kbd_event_fn(struct ssam_event_notifier *nf, const struct ssam_event *event) +{ + struct surface_hid_device *shid = container_of(nf, struct surface_hid_device, notif); + + /* + * Check against device UID manually, as registry and device target + * category doesn't line up. + */ + + if (shid->uid.category != event->target_category) + return 0; + + if (shid->uid.target != event->target_id) + return 0; + + if (shid->uid.instance != event->instance_id) + return 0; + + if (!ssam_kbd_is_input_event(event)) + return 0; + + hid_input_report(shid->hid, HID_INPUT_REPORT, (u8 *)&event->data[0], event->length, 0); + return SSAM_NOTIF_HANDLED; +} + + +/* -- Transport driver (KBD). ----------------------------------------------- */ + +static int skbd_get_caps_led_value(struct hid_device *hid, u8 rprt_id, u8 *buf, size_t len) +{ + struct hid_field *field; + unsigned int offset, size; + int i; + + /* Get LED field. */ + field = hidinput_get_led_field(hid); + if (!field) + return -ENOENT; + + /* Check if we got the correct report. */ + if (len != hid_report_len(field->report)) + return -ENOENT; + + if (rprt_id != field->report->id) + return -ENOENT; + + /* Get caps lock LED index. */ + for (i = 0; i < field->report_count; i++) + if ((field->usage[i].hid & 0xffff) == 0x02) + break; + + if (i == field->report_count) + return -ENOENT; + + /* Extract value. */ + size = field->report_size; + offset = field->report_offset + i * size; + return !!hid_field_extract(hid, buf + 1, size, offset); +} + +static int skbd_output_report(struct surface_hid_device *shid, u8 rprt_id, u8 *buf, size_t len) +{ + int caps_led; + int status; + + caps_led = skbd_get_caps_led_value(shid->hid, rprt_id, buf, len); + if (caps_led < 0) + return -EIO; /* Only caps LED output reports are supported. */ + + status = ssam_kbd_set_caps_led(shid, caps_led); + if (status < 0) + return status; + + return len; +} + +static int skbd_get_feature_report(struct surface_hid_device *shid, u8 rprt_id, u8 *buf, size_t len) +{ + u8 report[KBD_FEATURE_REPORT_SIZE]; + int status; + + /* + * The keyboard only has a single hard-coded read-only feature report + * of size KBD_FEATURE_REPORT_SIZE. Try to load it and compare its + * report ID against the requested one. + */ + + if (len < ARRAY_SIZE(report)) + return -ENOSPC; + + status = ssam_kbd_get_feature_report(shid, report, ARRAY_SIZE(report)); + if (status < 0) + return status; + + if (rprt_id != report[0]) + return -ENOENT; + + memcpy(buf, report, ARRAY_SIZE(report)); + return len; +} + +static int skbd_set_feature_report(struct surface_hid_device *shid, u8 rprt_id, u8 *buf, size_t len) +{ + /* Not supported. See skbd_get_feature_report() for details. */ + return -EIO; +} + + +/* -- Driver setup. --------------------------------------------------------- */ + +static int surface_kbd_probe(struct platform_device *pdev) +{ + struct ssam_controller *ctrl; + struct surface_hid_device *shid; + + /* Add device link to EC. */ + ctrl = ssam_client_bind(&pdev->dev); + if (IS_ERR(ctrl)) + return PTR_ERR(ctrl) == -ENODEV ? -EPROBE_DEFER : PTR_ERR(ctrl); + + shid = devm_kzalloc(&pdev->dev, sizeof(*shid), GFP_KERNEL); + if (!shid) + return -ENOMEM; + + shid->dev = &pdev->dev; + shid->ctrl = ctrl; + + shid->uid.domain = SSAM_DOMAIN_SERIALHUB; + shid->uid.category = SSAM_SSH_TC_KBD; + shid->uid.target = 2; + shid->uid.instance = 0; + shid->uid.function = 0; + + shid->notif.base.priority = 1; + shid->notif.base.fn = ssam_kbd_event_fn; + shid->notif.event.reg = SSAM_EVENT_REGISTRY_SAM; + shid->notif.event.id.target_category = shid->uid.category; + shid->notif.event.id.instance = shid->uid.instance; + shid->notif.event.mask = SSAM_EVENT_MASK_NONE; + shid->notif.event.flags = 0; + + shid->ops.get_descriptor = ssam_kbd_get_descriptor; + shid->ops.output_report = skbd_output_report; + shid->ops.get_feature_report = skbd_get_feature_report; + shid->ops.set_feature_report = skbd_set_feature_report; + + platform_set_drvdata(pdev, shid); + return surface_hid_device_add(shid); +} + +static int surface_kbd_remove(struct platform_device *pdev) +{ + surface_hid_device_destroy(platform_get_drvdata(pdev)); + return 0; +} + +static const struct acpi_device_id surface_kbd_match[] = { + { "MSHW0096" }, + { }, +}; +MODULE_DEVICE_TABLE(acpi, surface_kbd_match); + +static struct platform_driver surface_kbd_driver = { + .probe = surface_kbd_probe, + .remove = surface_kbd_remove, + .driver = { + .name = "surface_keyboard", + .acpi_match_table = surface_kbd_match, + .pm = &surface_hid_pm_ops, + .probe_type = PROBE_PREFER_ASYNCHRONOUS, + }, +}; +module_platform_driver(surface_kbd_driver); + +MODULE_AUTHOR("Maximilian Luz "); +MODULE_DESCRIPTION("HID legacy transport driver for Surface System Aggregator Module"); +MODULE_LICENSE("GPL");