diff options
Diffstat (limited to 'drivers/hid/hid-lg3ff.c')
| -rw-r--r-- | drivers/hid/hid-lg3ff.c | 151 |
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; +} + |