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-rw-r--r--drivers/hid/hid-vivaldi-common.c141
1 files changed, 141 insertions, 0 deletions
diff --git a/drivers/hid/hid-vivaldi-common.c b/drivers/hid/hid-vivaldi-common.c
new file mode 100644
index 000000000..b0af2be94
--- /dev/null
+++ b/drivers/hid/hid-vivaldi-common.c
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Helpers for ChromeOS HID Vivaldi keyboards
+ *
+ * Copyright (C) 2022 Google, Inc
+ */
+
+#include <linux/export.h>
+#include <linux/hid.h>
+#include <linux/input/vivaldi-fmap.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+
+#include "hid-vivaldi-common.h"
+
+#define MIN_FN_ROW_KEY 1
+#define MAX_FN_ROW_KEY VIVALDI_MAX_FUNCTION_ROW_KEYS
+#define HID_VD_FN_ROW_PHYSMAP 0x00000001
+#define HID_USAGE_FN_ROW_PHYSMAP (HID_UP_GOOGLEVENDOR | HID_VD_FN_ROW_PHYSMAP)
+
+/**
+ * vivaldi_feature_mapping - Fill out vivaldi keymap data exposed via HID
+ * @hdev: HID device to parse
+ * @field: HID field to parse
+ * @usage: HID usage to parse
+ *
+ * Note: this function assumes that driver data attached to @hdev contains an
+ * instance of &struct vivaldi_data at the very beginning.
+ */
+void vivaldi_feature_mapping(struct hid_device *hdev,
+ struct hid_field *field, struct hid_usage *usage)
+{
+ struct vivaldi_data *data = hid_get_drvdata(hdev);
+ struct hid_report *report = field->report;
+ u8 *report_data, *buf;
+ u32 report_len;
+ unsigned int fn_key;
+ int ret;
+
+ if (field->logical != HID_USAGE_FN_ROW_PHYSMAP ||
+ (usage->hid & HID_USAGE_PAGE) != HID_UP_ORDINAL)
+ return;
+
+ fn_key = usage->hid & HID_USAGE;
+ if (fn_key < MIN_FN_ROW_KEY || fn_key > MAX_FN_ROW_KEY)
+ return;
+
+ if (fn_key > data->num_function_row_keys)
+ data->num_function_row_keys = fn_key;
+
+ report_data = buf = hid_alloc_report_buf(report, GFP_KERNEL);
+ if (!report_data)
+ return;
+
+ report_len = hid_report_len(report);
+ if (!report->id) {
+ /*
+ * hid_hw_raw_request() will stuff report ID (which will be 0)
+ * into the first byte of the buffer even for unnumbered
+ * reports, so we need to account for this to avoid getting
+ * -EOVERFLOW in return.
+ * Note that hid_alloc_report_buf() adds 7 bytes to the size
+ * so we can safely say that we have space for an extra byte.
+ */
+ report_len++;
+ }
+
+ ret = hid_hw_raw_request(hdev, report->id, report_data,
+ report_len, HID_FEATURE_REPORT,
+ HID_REQ_GET_REPORT);
+ if (ret < 0) {
+ dev_warn(&hdev->dev, "failed to fetch feature %d\n",
+ field->report->id);
+ goto out;
+ }
+
+ if (!report->id) {
+ /*
+ * Undo the damage from hid_hw_raw_request() for unnumbered
+ * reports.
+ */
+ report_data++;
+ report_len--;
+ }
+
+ ret = hid_report_raw_event(hdev, HID_FEATURE_REPORT, report_data,
+ report_len, 0);
+ if (ret) {
+ dev_warn(&hdev->dev, "failed to report feature %d\n",
+ field->report->id);
+ goto out;
+ }
+
+ data->function_row_physmap[fn_key - MIN_FN_ROW_KEY] =
+ field->value[usage->usage_index];
+
+out:
+ kfree(buf);
+}
+EXPORT_SYMBOL_GPL(vivaldi_feature_mapping);
+
+static ssize_t function_row_physmap_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct hid_device *hdev = to_hid_device(dev);
+ struct vivaldi_data *data = hid_get_drvdata(hdev);
+
+ return vivaldi_function_row_physmap_show(data, buf);
+}
+
+static DEVICE_ATTR_RO(function_row_physmap);
+static struct attribute *vivaldi_sysfs_attrs[] = {
+ &dev_attr_function_row_physmap.attr,
+ NULL
+};
+
+static umode_t vivaldi_is_visible(struct kobject *kobj, struct attribute *attr,
+ int n)
+{
+ struct hid_device *hdev = to_hid_device(kobj_to_dev(kobj));
+ struct vivaldi_data *data = hid_get_drvdata(hdev);
+
+ if (!data->num_function_row_keys)
+ return 0;
+ return attr->mode;
+}
+
+static const struct attribute_group vivaldi_attribute_group = {
+ .attrs = vivaldi_sysfs_attrs,
+ .is_visible = vivaldi_is_visible,
+};
+
+const struct attribute_group *vivaldi_attribute_groups[] = {
+ &vivaldi_attribute_group,
+ NULL,
+};
+EXPORT_SYMBOL_GPL(vivaldi_attribute_groups);
+
+MODULE_LICENSE("GPL");