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-rw-r--r--drivers/hid/hid-primax.c73
1 files changed, 73 insertions, 0 deletions
diff --git a/drivers/hid/hid-primax.c b/drivers/hid/hid-primax.c
new file mode 100644
index 000000000..1e6413d07
--- /dev/null
+++ b/drivers/hid/hid-primax.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * HID driver for primax and similar keyboards with in-band modifiers
+ *
+ * Copyright 2011 Google Inc. All Rights Reserved
+ *
+ * Author:
+ * Terry Lambert <tlambert@google.com>
+ */
+
+#include <linux/device.h>
+#include <linux/hid.h>
+#include <linux/module.h>
+
+#include "hid-ids.h"
+
+static int px_raw_event(struct hid_device *hid, struct hid_report *report,
+ u8 *data, int size)
+{
+ int idx = size;
+
+ switch (report->id) {
+ case 0: /* keyboard input */
+ /*
+ * Convert in-band modifier key values into out of band
+ * modifier bits and pull the key strokes from the report.
+ * Thus a report data set which looked like:
+ *
+ * [00][00][E0][30][00][00][00][00]
+ * (no modifier bits + "Left Shift" key + "1" key)
+ *
+ * Would be converted to:
+ *
+ * [01][00][00][30][00][00][00][00]
+ * (Left Shift modifier bit + "1" key)
+ *
+ * As long as it's in the size range, the upper level
+ * drivers don't particularly care if there are in-band
+ * 0-valued keys, so they don't stop parsing.
+ */
+ while (--idx > 1) {
+ if (data[idx] < 0xE0 || data[idx] > 0xE7)
+ continue;
+ data[0] |= (1 << (data[idx] - 0xE0));
+ data[idx] = 0;
+ }
+ hid_report_raw_event(hid, HID_INPUT_REPORT, data, size, 0);
+ return 1;
+
+ default: /* unknown report */
+ /* Unknown report type; pass upstream */
+ hid_info(hid, "unknown report type %d\n", report->id);
+ break;
+ }
+
+ return 0;
+}
+
+static const struct hid_device_id px_devices[] = {
+ { HID_USB_DEVICE(USB_VENDOR_ID_PRIMAX, USB_DEVICE_ID_PRIMAX_KEYBOARD) },
+ { }
+};
+MODULE_DEVICE_TABLE(hid, px_devices);
+
+static struct hid_driver px_driver = {
+ .name = "primax",
+ .id_table = px_devices,
+ .raw_event = px_raw_event,
+};
+module_hid_driver(px_driver);
+
+MODULE_AUTHOR("Terry Lambert <tlambert@google.com>");
+MODULE_LICENSE("GPL");