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-rw-r--r--drivers/hid/hid-lg3ff.c151
1 files changed, 151 insertions, 0 deletions
diff --git a/drivers/hid/hid-lg3ff.c b/drivers/hid/hid-lg3ff.c
new file mode 100644
index 000000000..b7e1949f3
--- /dev/null
+++ b/drivers/hid/hid-lg3ff.c
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Force feedback support for Logitech Flight System G940
+ *
+ * Copyright (c) 2009 Gary Stein <LordCnidarian@gmail.com>
+ */
+
+/*
+ */
+
+
+#include <linux/input.h>
+#include <linux/hid.h>
+
+#include "hid-lg.h"
+
+/*
+ * G940 Theory of Operation (from experimentation)
+ *
+ * There are 63 fields (only 3 of them currently used)
+ * 0 - seems to be command field
+ * 1 - 30 deal with the x axis
+ * 31 -60 deal with the y axis
+ *
+ * Field 1 is x axis constant force
+ * Field 31 is y axis constant force
+ *
+ * other interesting fields 1,2,3,4 on x axis
+ * (same for 31,32,33,34 on y axis)
+ *
+ * 0 0 127 127 makes the joystick autocenter hard
+ *
+ * 127 0 127 127 makes the joystick loose on the right,
+ * but stops all movemnt left
+ *
+ * -127 0 -127 -127 makes the joystick loose on the left,
+ * but stops all movement right
+ *
+ * 0 0 -127 -127 makes the joystick rattle very hard
+ *
+ * I'm sure these are effects that I don't know enough about them
+ */
+
+struct lg3ff_device {
+ struct hid_report *report;
+};
+
+static int hid_lg3ff_play(struct input_dev *dev, void *data,
+ struct ff_effect *effect)
+{
+ struct hid_device *hid = input_get_drvdata(dev);
+ struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
+ struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
+ int x, y;
+
+/*
+ * Available values in the field should always be 63, but we only use up to
+ * 35. Instead, clear the entire area, however big it is.
+ */
+ memset(report->field[0]->value, 0,
+ sizeof(__s32) * report->field[0]->report_count);
+
+ switch (effect->type) {
+ case FF_CONSTANT:
+/*
+ * Already clamped in ff_memless
+ * 0 is center (different then other logitech)
+ */
+ x = effect->u.ramp.start_level;
+ y = effect->u.ramp.end_level;
+
+ /* send command byte */
+ report->field[0]->value[0] = 0x51;
+
+/*
+ * Sign backwards from other Force3d pro
+ * which get recast here in two's complement 8 bits
+ */
+ report->field[0]->value[1] = (unsigned char)(-x);
+ report->field[0]->value[31] = (unsigned char)(-y);
+
+ hid_hw_request(hid, report, HID_REQ_SET_REPORT);
+ break;
+ }
+ return 0;
+}
+static void hid_lg3ff_set_autocenter(struct input_dev *dev, u16 magnitude)
+{
+ struct hid_device *hid = input_get_drvdata(dev);
+ struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
+ struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
+
+/*
+ * Auto Centering probed from device
+ * NOTE: deadman's switch on G940 must be covered
+ * for effects to work
+ */
+ report->field[0]->value[0] = 0x51;
+ report->field[0]->value[1] = 0x00;
+ report->field[0]->value[2] = 0x00;
+ report->field[0]->value[3] = 0x7F;
+ report->field[0]->value[4] = 0x7F;
+ report->field[0]->value[31] = 0x00;
+ report->field[0]->value[32] = 0x00;
+ report->field[0]->value[33] = 0x7F;
+ report->field[0]->value[34] = 0x7F;
+
+ hid_hw_request(hid, report, HID_REQ_SET_REPORT);
+}
+
+
+static const signed short ff3_joystick_ac[] = {
+ FF_CONSTANT,
+ FF_AUTOCENTER,
+ -1
+};
+
+int lg3ff_init(struct hid_device *hid)
+{
+ struct hid_input *hidinput;
+ struct input_dev *dev;
+ const signed short *ff_bits = ff3_joystick_ac;
+ int error;
+ int i;
+
+ if (list_empty(&hid->inputs)) {
+ hid_err(hid, "no inputs found\n");
+ return -ENODEV;
+ }
+ hidinput = list_entry(hid->inputs.next, struct hid_input, list);
+ dev = hidinput->input;
+
+ /* Check that the report looks ok */
+ if (!hid_validate_values(hid, HID_OUTPUT_REPORT, 0, 0, 35))
+ return -ENODEV;
+
+ /* Assume single fixed device G940 */
+ for (i = 0; ff_bits[i] >= 0; i++)
+ set_bit(ff_bits[i], dev->ffbit);
+
+ error = input_ff_create_memless(dev, NULL, hid_lg3ff_play);
+ if (error)
+ return error;
+
+ if (test_bit(FF_AUTOCENTER, dev->ffbit))
+ dev->ff->set_autocenter = hid_lg3ff_set_autocenter;
+
+ hid_info(hid, "Force feedback for Logitech Flight System G940 by Gary Stein <LordCnidarian@gmail.com>\n");
+ return 0;
+}
+