diff options
Diffstat (limited to 'drivers/hid/surface-hid')
| -rw-r--r-- | drivers/hid/surface-hid/Kconfig | 42 | ||||
| -rw-r--r-- | drivers/hid/surface-hid/Makefile | 7 | ||||
| -rw-r--r-- | drivers/hid/surface-hid/surface_hid.c | 253 | ||||
| -rw-r--r-- | drivers/hid/surface-hid/surface_hid_core.c | 293 | ||||
| -rw-r--r-- | drivers/hid/surface-hid/surface_hid_core.h | 77 | ||||
| -rw-r--r-- | drivers/hid/surface-hid/surface_kbd.c | 300 |
6 files changed, 972 insertions, 0 deletions
diff --git a/drivers/hid/surface-hid/Kconfig b/drivers/hid/surface-hid/Kconfig new file mode 100644 index 000000000..7ce9b5d64 --- /dev/null +++ b/drivers/hid/surface-hid/Kconfig @@ -0,0 +1,42 @@ +# SPDX-License-Identifier: GPL-2.0+ +menu "Surface System Aggregator Module HID support" + depends on SURFACE_AGGREGATOR + depends on INPUT + +config SURFACE_HID + tristate "HID transport driver for Surface System Aggregator Module" + depends on SURFACE_AGGREGATOR_REGISTRY + select SURFACE_HID_CORE + help + Driver to support integrated HID devices on newer Microsoft Surface + models. + + This driver provides support for the HID transport protocol provided + by the Surface Aggregator Module (i.e. the embedded controller) on + 7th-generation Microsoft Surface devices, i.e. Surface Book 3 and + Surface Laptop 3. On those models, it is mainly used to connect the + integrated touchpad and keyboard. + + Say M or Y here, if you want support for integrated HID devices, i.e. + 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 + tristate + select HID diff --git a/drivers/hid/surface-hid/Makefile b/drivers/hid/surface-hid/Makefile new file mode 100644 index 000000000..4ae11cf09 --- /dev/null +++ b/drivers/hid/surface-hid/Makefile @@ -0,0 +1,7 @@ +# SPDX-License-Identifier: GPL-2.0+ +# +# Makefile - Surface System Aggregator Module (SSAM) HID transport driver. +# +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_hid.c b/drivers/hid/surface-hid/surface_hid.c new file mode 100644 index 000000000..d4aa8c819 --- /dev/null +++ b/drivers/hid/surface-hid/surface_hid.c @@ -0,0 +1,253 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Surface System Aggregator Module (SSAM) HID transport driver for the + * generic HID interface (HID/TC=0x15 subsystem). Provides support for + * integrated HID devices on Surface Laptop 3, Book 3, and later. + * + * Copyright (C) 2019-2021 Blaž Hrastnik <blaz@mxxn.io>, + * Maximilian Luz <luzmaximilian@gmail.com> + */ + +#include <asm/unaligned.h> +#include <linux/hid.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/types.h> + +#include <linux/surface_aggregator/controller.h> +#include <linux/surface_aggregator/device.h> + +#include "surface_hid_core.h" + + +/* -- SAM interface. -------------------------------------------------------- */ + +struct surface_hid_buffer_slice { + __u8 entry; + __le32 offset; + __le32 length; + __u8 end; + __u8 data[]; +} __packed; + +static_assert(sizeof(struct surface_hid_buffer_slice) == 10); + +enum surface_hid_cid { + SURFACE_HID_CID_OUTPUT_REPORT = 0x01, + SURFACE_HID_CID_GET_FEATURE_REPORT = 0x02, + SURFACE_HID_CID_SET_FEATURE_REPORT = 0x03, + SURFACE_HID_CID_GET_DESCRIPTOR = 0x04, +}; + +static int ssam_hid_get_descriptor(struct surface_hid_device *shid, u8 entry, u8 *buf, size_t len) +{ + u8 buffer[sizeof(struct surface_hid_buffer_slice) + 0x76]; + struct surface_hid_buffer_slice *slice; + struct ssam_request rqst; + struct ssam_response rsp; + u32 buffer_len, offset, length; + int status; + + /* + * Note: The 0x76 above has been chosen because that's what's used by + * the Windows driver. Together with the header, this leads to a 128 + * byte payload in total. + */ + + buffer_len = ARRAY_SIZE(buffer) - sizeof(struct surface_hid_buffer_slice); + + rqst.target_category = shid->uid.category; + rqst.target_id = shid->uid.target; + rqst.command_id = SURFACE_HID_CID_GET_DESCRIPTOR; + rqst.instance_id = shid->uid.instance; + rqst.flags = SSAM_REQUEST_HAS_RESPONSE; + rqst.length = sizeof(struct surface_hid_buffer_slice); + rqst.payload = buffer; + + rsp.capacity = ARRAY_SIZE(buffer); + rsp.pointer = buffer; + + slice = (struct surface_hid_buffer_slice *)buffer; + slice->entry = entry; + slice->end = 0; + + offset = 0; + length = buffer_len; + + while (!slice->end && offset < len) { + put_unaligned_le32(offset, &slice->offset); + put_unaligned_le32(length, &slice->length); + + rsp.length = 0; + + status = ssam_retry(ssam_request_sync_onstack, shid->ctrl, &rqst, &rsp, + sizeof(*slice)); + if (status) + return status; + + offset = get_unaligned_le32(&slice->offset); + length = get_unaligned_le32(&slice->length); + + /* Don't mess stuff up in case we receive garbage. */ + if (length > buffer_len || offset > len) + return -EPROTO; + + if (offset + length > len) + length = len - offset; + + memcpy(buf + offset, &slice->data[0], length); + + offset += length; + length = buffer_len; + } + + if (offset != len) { + dev_err(shid->dev, "unexpected descriptor length: got %u, expected %zu\n", + offset, len); + return -EPROTO; + } + + return 0; +} + +static int ssam_hid_set_raw_report(struct surface_hid_device *shid, u8 rprt_id, bool feature, + u8 *buf, size_t len) +{ + struct ssam_request rqst; + u8 cid; + + if (feature) + cid = SURFACE_HID_CID_SET_FEATURE_REPORT; + else + cid = SURFACE_HID_CID_OUTPUT_REPORT; + + rqst.target_category = shid->uid.category; + rqst.target_id = shid->uid.target; + rqst.instance_id = shid->uid.instance; + rqst.command_id = cid; + rqst.flags = 0; + rqst.length = len; + rqst.payload = buf; + + buf[0] = rprt_id; + + return ssam_retry(ssam_request_sync, shid->ctrl, &rqst, NULL); +} + +static int ssam_hid_get_raw_report(struct surface_hid_device *shid, u8 rprt_id, u8 *buf, size_t len) +{ + struct ssam_request rqst; + struct ssam_response rsp; + + rqst.target_category = shid->uid.category; + rqst.target_id = shid->uid.target; + rqst.instance_id = shid->uid.instance; + rqst.command_id = SURFACE_HID_CID_GET_FEATURE_REPORT; + rqst.flags = SSAM_REQUEST_HAS_RESPONSE; + rqst.length = sizeof(rprt_id); + rqst.payload = &rprt_id; + + rsp.capacity = len; + rsp.length = 0; + rsp.pointer = buf; + + return ssam_retry(ssam_request_sync_onstack, shid->ctrl, &rqst, &rsp, sizeof(rprt_id)); +} + +static u32 ssam_hid_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); + + if (event->command_id != 0x00) + return 0; + + hid_input_report(shid->hid, HID_INPUT_REPORT, (u8 *)&event->data[0], event->length, 0); + return SSAM_NOTIF_HANDLED; +} + + +/* -- Transport driver. ----------------------------------------------------- */ + +static int shid_output_report(struct surface_hid_device *shid, u8 rprt_id, u8 *buf, size_t len) +{ + int status; + + status = ssam_hid_set_raw_report(shid, rprt_id, false, buf, len); + return status >= 0 ? len : status; +} + +static int shid_get_feature_report(struct surface_hid_device *shid, u8 rprt_id, u8 *buf, size_t len) +{ + int status; + + status = ssam_hid_get_raw_report(shid, rprt_id, buf, len); + return status >= 0 ? len : status; +} + +static int shid_set_feature_report(struct surface_hid_device *shid, u8 rprt_id, u8 *buf, size_t len) +{ + int status; + + status = ssam_hid_set_raw_report(shid, rprt_id, true, buf, len); + return status >= 0 ? len : status; +} + + +/* -- Driver setup. --------------------------------------------------------- */ + +static int surface_hid_probe(struct ssam_device *sdev) +{ + struct surface_hid_device *shid; + + shid = devm_kzalloc(&sdev->dev, sizeof(*shid), GFP_KERNEL); + if (!shid) + return -ENOMEM; + + shid->dev = &sdev->dev; + shid->ctrl = sdev->ctrl; + shid->uid = sdev->uid; + + shid->notif.base.priority = 1; + shid->notif.base.fn = ssam_hid_event_fn; + shid->notif.event.reg = SSAM_EVENT_REGISTRY_REG(sdev->uid.target); + shid->notif.event.id.target_category = sdev->uid.category; + shid->notif.event.id.instance = sdev->uid.instance; + shid->notif.event.mask = SSAM_EVENT_MASK_STRICT; + shid->notif.event.flags = 0; + + shid->ops.get_descriptor = ssam_hid_get_descriptor; + shid->ops.output_report = shid_output_report; + shid->ops.get_feature_report = shid_get_feature_report; + shid->ops.set_feature_report = shid_set_feature_report; + + ssam_device_set_drvdata(sdev, shid); + return surface_hid_device_add(shid); +} + +static void surface_hid_remove(struct ssam_device *sdev) +{ + surface_hid_device_destroy(ssam_device_get_drvdata(sdev)); +} + +static const struct ssam_device_id surface_hid_match[] = { + { SSAM_SDEV(HID, SSAM_ANY_TID, SSAM_ANY_IID, 0x00) }, + { }, +}; +MODULE_DEVICE_TABLE(ssam, surface_hid_match); + +static struct ssam_device_driver surface_hid_driver = { + .probe = surface_hid_probe, + .remove = surface_hid_remove, + .match_table = surface_hid_match, + .driver = { + .name = "surface_hid", + .pm = &surface_hid_pm_ops, + .probe_type = PROBE_PREFER_ASYNCHRONOUS, + }, +}; +module_ssam_device_driver(surface_hid_driver); + +MODULE_AUTHOR("Blaž Hrastnik <blaz@mxxn.io>"); +MODULE_AUTHOR("Maximilian Luz <luzmaximilian@gmail.com>"); +MODULE_DESCRIPTION("HID transport driver for Surface System Aggregator Module"); +MODULE_LICENSE("GPL"); diff --git a/drivers/hid/surface-hid/surface_hid_core.c b/drivers/hid/surface-hid/surface_hid_core.c new file mode 100644 index 000000000..87637f813 --- /dev/null +++ b/drivers/hid/surface-hid/surface_hid_core.c @@ -0,0 +1,293 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Common/core components for the Surface System Aggregator Module (SSAM) HID + * transport driver. Provides support for integrated HID devices on Microsoft + * Surface models. + * + * Copyright (C) 2019-2021 Maximilian Luz <luzmaximilian@gmail.com> + */ + +#include <asm/unaligned.h> +#include <linux/hid.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/usb/ch9.h> + +#include <linux/surface_aggregator/controller.h> + +#include "surface_hid_core.h" + + +/* -- Utility functions. ---------------------------------------------------- */ + +static bool surface_hid_is_hot_removed(struct surface_hid_device *shid) +{ + /* + * Non-ssam client devices, i.e. platform client devices, cannot be + * hot-removed. + */ + if (!is_ssam_device(shid->dev)) + return false; + + return ssam_device_is_hot_removed(to_ssam_device(shid->dev)); +} + + +/* -- Device descriptor access. --------------------------------------------- */ + +static int surface_hid_load_hid_descriptor(struct surface_hid_device *shid) +{ + int status; + + if (surface_hid_is_hot_removed(shid)) + return -ENODEV; + + status = shid->ops.get_descriptor(shid, SURFACE_HID_DESC_HID, + (u8 *)&shid->hid_desc, sizeof(shid->hid_desc)); + if (status) + return status; + + if (shid->hid_desc.desc_len != sizeof(shid->hid_desc)) { + dev_err(shid->dev, "unexpected HID descriptor length: got %u, expected %zu\n", + shid->hid_desc.desc_len, sizeof(shid->hid_desc)); + return -EPROTO; + } + + if (shid->hid_desc.desc_type != HID_DT_HID) { + dev_err(shid->dev, "unexpected HID descriptor type: got %#04x, expected %#04x\n", + shid->hid_desc.desc_type, HID_DT_HID); + return -EPROTO; + } + + if (shid->hid_desc.num_descriptors != 1) { + dev_err(shid->dev, "unexpected number of descriptors: got %u, expected 1\n", + shid->hid_desc.num_descriptors); + return -EPROTO; + } + + if (shid->hid_desc.report_desc_type != HID_DT_REPORT) { + dev_err(shid->dev, "unexpected report descriptor type: got %#04x, expected %#04x\n", + shid->hid_desc.report_desc_type, HID_DT_REPORT); + return -EPROTO; + } + + return 0; +} + +static int surface_hid_load_device_attributes(struct surface_hid_device *shid) +{ + int status; + + if (surface_hid_is_hot_removed(shid)) + return -ENODEV; + + status = shid->ops.get_descriptor(shid, SURFACE_HID_DESC_ATTRS, + (u8 *)&shid->attrs, sizeof(shid->attrs)); + if (status) + return status; + + if (get_unaligned_le32(&shid->attrs.length) != sizeof(shid->attrs)) { + dev_err(shid->dev, "unexpected attribute length: got %u, expected %zu\n", + get_unaligned_le32(&shid->attrs.length), sizeof(shid->attrs)); + return -EPROTO; + } + + return 0; +} + + +/* -- Transport driver (common). -------------------------------------------- */ + +static int surface_hid_start(struct hid_device *hid) +{ + struct surface_hid_device *shid = hid->driver_data; + + return ssam_notifier_register(shid->ctrl, &shid->notif); +} + +static void surface_hid_stop(struct hid_device *hid) +{ + struct surface_hid_device *shid = hid->driver_data; + bool hot_removed; + + /* + * Communication may fail for devices that have been hot-removed. This + * also includes unregistration of HID events, so we need to check this + * here. Only if the device has not been marked as hot-removed, we can + * safely disable events. + */ + hot_removed = surface_hid_is_hot_removed(shid); + + /* Note: This call will log errors for us, so ignore them here. */ + __ssam_notifier_unregister(shid->ctrl, &shid->notif, !hot_removed); +} + +static int surface_hid_open(struct hid_device *hid) +{ + return 0; +} + +static void surface_hid_close(struct hid_device *hid) +{ +} + +static int surface_hid_parse(struct hid_device *hid) +{ + struct surface_hid_device *shid = hid->driver_data; + size_t len = get_unaligned_le16(&shid->hid_desc.report_desc_len); + u8 *buf; + int status; + + if (surface_hid_is_hot_removed(shid)) + return -ENODEV; + + buf = kzalloc(len, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + status = shid->ops.get_descriptor(shid, SURFACE_HID_DESC_REPORT, buf, len); + if (!status) + status = hid_parse_report(hid, buf, len); + + kfree(buf); + return status; +} + +static int surface_hid_raw_request(struct hid_device *hid, unsigned char reportnum, u8 *buf, + size_t len, unsigned char rtype, int reqtype) +{ + struct surface_hid_device *shid = hid->driver_data; + + if (surface_hid_is_hot_removed(shid)) + return -ENODEV; + + if (rtype == HID_OUTPUT_REPORT && reqtype == HID_REQ_SET_REPORT) + return shid->ops.output_report(shid, reportnum, buf, len); + + else if (rtype == HID_FEATURE_REPORT && reqtype == HID_REQ_GET_REPORT) + return shid->ops.get_feature_report(shid, reportnum, buf, len); + + else if (rtype == HID_FEATURE_REPORT && reqtype == HID_REQ_SET_REPORT) + return shid->ops.set_feature_report(shid, reportnum, buf, len); + + return -EIO; +} + +static struct hid_ll_driver surface_hid_ll_driver = { + .start = surface_hid_start, + .stop = surface_hid_stop, + .open = surface_hid_open, + .close = surface_hid_close, + .parse = surface_hid_parse, + .raw_request = surface_hid_raw_request, +}; + + +/* -- Common device setup. -------------------------------------------------- */ + +int surface_hid_device_add(struct surface_hid_device *shid) +{ + int status; + + status = surface_hid_load_hid_descriptor(shid); + if (status) + return status; + + status = surface_hid_load_device_attributes(shid); + if (status) + return status; + + shid->hid = hid_allocate_device(); + if (IS_ERR(shid->hid)) + return PTR_ERR(shid->hid); + + shid->hid->dev.parent = shid->dev; + shid->hid->bus = BUS_HOST; + shid->hid->vendor = get_unaligned_le16(&shid->attrs.vendor); + shid->hid->product = get_unaligned_le16(&shid->attrs.product); + shid->hid->version = get_unaligned_le16(&shid->hid_desc.hid_version); + shid->hid->country = shid->hid_desc.country_code; + + snprintf(shid->hid->name, sizeof(shid->hid->name), "Microsoft Surface %04X:%04X", + shid->hid->vendor, shid->hid->product); + + strscpy(shid->hid->phys, dev_name(shid->dev), sizeof(shid->hid->phys)); + + shid->hid->driver_data = shid; + shid->hid->ll_driver = &surface_hid_ll_driver; + + status = hid_add_device(shid->hid); + if (status) + hid_destroy_device(shid->hid); + + return status; +} +EXPORT_SYMBOL_GPL(surface_hid_device_add); + +void surface_hid_device_destroy(struct surface_hid_device *shid) +{ + hid_destroy_device(shid->hid); +} +EXPORT_SYMBOL_GPL(surface_hid_device_destroy); + + +/* -- PM ops. --------------------------------------------------------------- */ + +#ifdef CONFIG_PM_SLEEP + +static int surface_hid_suspend(struct device *dev) +{ + struct surface_hid_device *d = dev_get_drvdata(dev); + + return hid_driver_suspend(d->hid, PMSG_SUSPEND); +} + +static int surface_hid_resume(struct device *dev) +{ + struct surface_hid_device *d = dev_get_drvdata(dev); + + return hid_driver_resume(d->hid); +} + +static int surface_hid_freeze(struct device *dev) +{ + struct surface_hid_device *d = dev_get_drvdata(dev); + + return hid_driver_suspend(d->hid, PMSG_FREEZE); +} + +static int surface_hid_poweroff(struct device *dev) +{ + struct surface_hid_device *d = dev_get_drvdata(dev); + + return hid_driver_suspend(d->hid, PMSG_HIBERNATE); +} + +static int surface_hid_restore(struct device *dev) +{ + struct surface_hid_device *d = dev_get_drvdata(dev); + + return hid_driver_reset_resume(d->hid); +} + +const struct dev_pm_ops surface_hid_pm_ops = { + .freeze = surface_hid_freeze, + .thaw = surface_hid_resume, + .suspend = surface_hid_suspend, + .resume = surface_hid_resume, + .poweroff = surface_hid_poweroff, + .restore = surface_hid_restore, +}; +EXPORT_SYMBOL_GPL(surface_hid_pm_ops); + +#else /* CONFIG_PM_SLEEP */ + +const struct dev_pm_ops surface_hid_pm_ops = { }; +EXPORT_SYMBOL_GPL(surface_hid_pm_ops); + +#endif /* CONFIG_PM_SLEEP */ + +MODULE_AUTHOR("Maximilian Luz <luzmaximilian@gmail.com>"); +MODULE_DESCRIPTION("HID transport driver core for Surface System Aggregator Module"); +MODULE_LICENSE("GPL"); diff --git a/drivers/hid/surface-hid/surface_hid_core.h b/drivers/hid/surface-hid/surface_hid_core.h new file mode 100644 index 000000000..4b1a7b57e --- /dev/null +++ b/drivers/hid/surface-hid/surface_hid_core.h @@ -0,0 +1,77 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Common/core components for the Surface System Aggregator Module (SSAM) HID + * transport driver. Provides support for integrated HID devices on Microsoft + * Surface models. + * + * Copyright (C) 2019-2021 Maximilian Luz <luzmaximilian@gmail.com> + */ + +#ifndef SURFACE_HID_CORE_H +#define SURFACE_HID_CORE_H + +#include <linux/hid.h> +#include <linux/pm.h> +#include <linux/types.h> + +#include <linux/surface_aggregator/controller.h> +#include <linux/surface_aggregator/device.h> + +enum surface_hid_descriptor_entry { + SURFACE_HID_DESC_HID = 0, + SURFACE_HID_DESC_REPORT = 1, + SURFACE_HID_DESC_ATTRS = 2, +}; + +struct surface_hid_descriptor { + __u8 desc_len; /* = 9 */ + __u8 desc_type; /* = HID_DT_HID */ + __le16 hid_version; + __u8 country_code; + __u8 num_descriptors; /* = 1 */ + + __u8 report_desc_type; /* = HID_DT_REPORT */ + __le16 report_desc_len; +} __packed; + +static_assert(sizeof(struct surface_hid_descriptor) == 9); + +struct surface_hid_attributes { + __le32 length; + __le16 vendor; + __le16 product; + __le16 version; + __u8 _unknown[22]; +} __packed; + +static_assert(sizeof(struct surface_hid_attributes) == 32); + +struct surface_hid_device; + +struct surface_hid_device_ops { + int (*get_descriptor)(struct surface_hid_device *shid, u8 entry, u8 *buf, size_t len); + int (*output_report)(struct surface_hid_device *shid, u8 rprt_id, u8 *buf, size_t len); + int (*get_feature_report)(struct surface_hid_device *shid, u8 rprt_id, u8 *buf, size_t len); + int (*set_feature_report)(struct surface_hid_device *shid, u8 rprt_id, u8 *buf, size_t len); +}; + +struct surface_hid_device { + struct device *dev; + struct ssam_controller *ctrl; + struct ssam_device_uid uid; + + struct surface_hid_descriptor hid_desc; + struct surface_hid_attributes attrs; + + struct ssam_event_notifier notif; + struct hid_device *hid; + + struct surface_hid_device_ops ops; +}; + +int surface_hid_device_add(struct surface_hid_device *shid); +void surface_hid_device_destroy(struct surface_hid_device *shid); + +extern const struct dev_pm_ops surface_hid_pm_ops; + +#endif /* SURFACE_HID_CORE_H */ diff --git a/drivers/hid/surface-hid/surface_kbd.c b/drivers/hid/surface-hid/surface_kbd.c new file mode 100644 index 000000000..0635341bc --- /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 <luzmaximilian@gmail.com> + */ + +#include <asm/unaligned.h> +#include <linux/hid.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/types.h> + +#include <linux/surface_aggregator/controller.h> + +#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 <luzmaximilian@gmail.com>"); +MODULE_DESCRIPTION("HID legacy transport driver for Surface System Aggregator Module"); +MODULE_LICENSE("GPL"); |