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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/hid/surface-hid/surface_hid.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/hid/surface-hid/surface_hid.c')
-rw-r--r--drivers/hid/surface-hid/surface_hid.c253
1 files changed, 253 insertions, 0 deletions
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");