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HID: hid-lg4ff: Allow switching of Logitech gaming wheels between com…
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…patibility modes

Allow switching of Logitech gaming wheels between available compatibility modes
through sysfs. This only applies to multimode wheels.

Signed-off-by: Michal Malý <madcatxster@devoid-pointer.net>
Tested-by: Simon Wood <simon@mungewell.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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Michal Malý authored and Jiri Kosina committed Feb 18, 2015
1 parent a54dc77 commit f31a2de
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27 changes: 26 additions & 1 deletion Documentation/ABI/testing/sysfs-driver-hid-logitech-lg4ff
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Original file line number Diff line number Diff line change
Expand Up @@ -15,7 +15,32 @@ Description: Displays a set of alternate modes supported by a wheel. Each
Tag: Mode Name
Currently active mode is marked with an asterisk. List also
contains an abstract item "native" which always denotes the
native mode of the wheel.
native mode of the wheel. Echoing the mode tag switches the
wheel into the corresponding mode. Depending on the exact model
of the wheel not all listed modes might always be selectable.
If a wheel cannot be switched into the desired mode, -EINVAL
is returned accompanied with an explanatory message in the
kernel log.
This entry is not created for devices that have only one mode.

Currently supported mode switches:
Driving Force Pro:
DF-EX --> DFP

G25:
DF-EX --> DFP --> G25

G27:
DF-EX <*> DFP <-> G25 <-> G27
DF-EX <*--------> G25 <-> G27
DF-EX <*----------------> G27

DFGT:
DF-EX <*> DFP <-> DFGT
DF-EX <*--------> DFGT

* hid_logitech module must be loaded with lg4ff_no_autoswitch=1
parameter set in order for the switch to DF-EX mode to work.

What: /sys/bus/hid/drivers/logitech/<dev>/real_id
Date: Feb 2015
Expand Down
204 changes: 175 additions & 29 deletions drivers/hid/hid-lg4ff.c
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Original file line number Diff line number Diff line change
Expand Up @@ -201,26 +201,47 @@ static const struct lg4ff_wheel_ident_checklist lg4ff_main_checklist = {
};

/* Compatibility mode switching commands */
static const struct lg4ff_compat_mode_switch lg4ff_mode_switch_dfp = {
1,
{0xf8, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00}
/* EXT_CMD9 - Understood by G27 and DFGT */
static const struct lg4ff_compat_mode_switch lg4ff_mode_switch_ext09_dfex = {
2,
{0xf8, 0x0a, 0x00, 0x00, 0x00, 0x00, 0x00, /* Revert mode upon USB reset */
0xf8, 0x09, 0x00, 0x01, 0x00, 0x00, 0x00} /* Switch mode to DF-EX with detach */
};

static const struct lg4ff_compat_mode_switch lg4ff_mode_switch_dfgt = {
static const struct lg4ff_compat_mode_switch lg4ff_mode_switch_ext09_dfp = {
2,
{0xf8, 0x0a, 0x00, 0x00, 0x00, 0x00, 0x00, /* 1st command */
0xf8, 0x09, 0x03, 0x01, 0x00, 0x00, 0x00} /* 2nd command */
{0xf8, 0x0a, 0x00, 0x00, 0x00, 0x00, 0x00, /* Revert mode upon USB reset */
0xf8, 0x09, 0x01, 0x01, 0x00, 0x00, 0x00} /* Switch mode to DFP with detach */
};

static const struct lg4ff_compat_mode_switch lg4ff_mode_switch_g25 = {
1,
{0xf8, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00}
static const struct lg4ff_compat_mode_switch lg4ff_mode_switch_ext09_g25 = {
2,
{0xf8, 0x0a, 0x00, 0x00, 0x00, 0x00, 0x00, /* Revert mode upon USB reset */
0xf8, 0x09, 0x02, 0x01, 0x00, 0x00, 0x00} /* Switch mode to G25 with detach */
};

static const struct lg4ff_compat_mode_switch lg4ff_mode_switch_g27 = {
static const struct lg4ff_compat_mode_switch lg4ff_mode_switch_ext09_dfgt = {
2,
{0xf8, 0x0a, 0x00, 0x00, 0x00, 0x00, 0x00, /* 1st command */
0xf8, 0x09, 0x04, 0x01, 0x00, 0x00, 0x00} /* 2nd command */
{0xf8, 0x0a, 0x00, 0x00, 0x00, 0x00, 0x00, /* Revert mode upon USB reset */
0xf8, 0x09, 0x03, 0x01, 0x00, 0x00, 0x00} /* Switch mode to DFGT with detach */
};

static const struct lg4ff_compat_mode_switch lg4ff_mode_switch_ext09_g27 = {
2,
{0xf8, 0x0a, 0x00, 0x00, 0x00, 0x00, 0x00, /* Revert mode upon USB reset */
0xf8, 0x09, 0x04, 0x01, 0x00, 0x00, 0x00} /* Switch mode to G27 with detach */
};

/* EXT_CMD1 - Understood by DFP, G25, G27 and DFGT */
static const struct lg4ff_compat_mode_switch lg4ff_mode_switch_ext01_dfp = {
1,
{0xf8, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00}
};

/* EXT_CMD16 - Understood by G25 and G27 */
static const struct lg4ff_compat_mode_switch lg4ff_mode_switch_ext16_g25 = {
1,
{0xf8, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00}
};

/* Recalculates X axis value accordingly to currently selected range */
Expand Down Expand Up @@ -489,6 +510,63 @@ static void hid_lg4ff_set_range_dfp(struct hid_device *hid, __u16 range)
hid_hw_request(hid, report, HID_REQ_SET_REPORT);
}

static const struct lg4ff_compat_mode_switch *lg4ff_get_mode_switch_command(const u16 real_product_id, const u16 target_product_id)
{
switch (real_product_id) {
case USB_DEVICE_ID_LOGITECH_DFP_WHEEL:
switch (target_product_id) {
case USB_DEVICE_ID_LOGITECH_DFP_WHEEL:
return &lg4ff_mode_switch_ext01_dfp;
/* DFP can only be switched to its native mode */
default:
return NULL;
}
break;
case USB_DEVICE_ID_LOGITECH_G25_WHEEL:
switch (target_product_id) {
case USB_DEVICE_ID_LOGITECH_DFP_WHEEL:
return &lg4ff_mode_switch_ext01_dfp;
case USB_DEVICE_ID_LOGITECH_G25_WHEEL:
return &lg4ff_mode_switch_ext16_g25;
/* G25 can only be switched to DFP mode or its native mode */
default:
return NULL;
}
break;
case USB_DEVICE_ID_LOGITECH_G27_WHEEL:
switch (target_product_id) {
case USB_DEVICE_ID_LOGITECH_WHEEL:
return &lg4ff_mode_switch_ext09_dfex;
case USB_DEVICE_ID_LOGITECH_DFP_WHEEL:
return &lg4ff_mode_switch_ext09_dfp;
case USB_DEVICE_ID_LOGITECH_G25_WHEEL:
return &lg4ff_mode_switch_ext09_g25;
case USB_DEVICE_ID_LOGITECH_G27_WHEEL:
return &lg4ff_mode_switch_ext09_g27;
/* G27 can only be switched to DF-EX, DFP, G25 or its native mode */
default:
return NULL;
}
break;
case USB_DEVICE_ID_LOGITECH_DFGT_WHEEL:
switch (target_product_id) {
case USB_DEVICE_ID_LOGITECH_WHEEL:
return &lg4ff_mode_switch_ext09_dfex;
case USB_DEVICE_ID_LOGITECH_DFP_WHEEL:
return &lg4ff_mode_switch_ext09_dfp;
case USB_DEVICE_ID_LOGITECH_DFGT_WHEEL:
return &lg4ff_mode_switch_ext09_dfgt;
/* DFGT can only be switched to DF-EX, DFP or its native mode */
default:
return NULL;
}
break;
/* No other wheels have multiple modes */
default:
return NULL;
}
}

static int lg4ff_switch_compatibility_mode(struct hid_device *hid, const struct lg4ff_compat_mode_switch *s)
{
struct usb_device *usbdev = hid_to_usb_dev(hid);
Expand Down Expand Up @@ -558,7 +636,87 @@ static ssize_t lg4ff_alternate_modes_show(struct device *dev, struct device_attr

static ssize_t lg4ff_alternate_modes_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
return -ENOSYS;
struct hid_device *hid = to_hid_device(dev);
struct lg4ff_device_entry *entry;
struct lg_drv_data *drv_data;
const struct lg4ff_compat_mode_switch *s;
u16 target_product_id = 0;
int i, ret;
char *lbuf;

drv_data = hid_get_drvdata(hid);
if (!drv_data) {
hid_err(hid, "Private driver data not found!\n");
return -EINVAL;
}

entry = drv_data->device_props;
if (!entry) {
hid_err(hid, "Device properties not found!\n");
return -EINVAL;
}

/* Allow \n at the end of the input parameter */
lbuf = kasprintf(GFP_KERNEL, "%s", buf);
if (!lbuf)
return -ENOMEM;

i = strlen(lbuf);
if (lbuf[i-1] == '\n') {
if (i == 1) {
kfree(lbuf);
return -EINVAL;
}
lbuf[i-1] = '\0';
}

for (i = 0; i < LG4FF_MODE_MAX_IDX; i++) {
const u16 mode_product_id = lg4ff_alternate_modes[i].product_id;
const char *tag = lg4ff_alternate_modes[i].tag;

if (entry->alternate_modes & BIT(i)) {
if (!strcmp(tag, lbuf)) {
if (!mode_product_id)
target_product_id = entry->real_product_id;
else
target_product_id = mode_product_id;
break;
}
}
}

if (i == LG4FF_MODE_MAX_IDX) {
hid_info(hid, "Requested mode \"%s\" is not supported by the device\n", lbuf);
kfree(lbuf);
return -EINVAL;
}
kfree(lbuf); /* Not needed anymore */

if (target_product_id == entry->product_id) /* Nothing to do */
return count;

/* Automatic switching has to be disabled for the switch to DF-EX mode to work correctly */
if (target_product_id == USB_DEVICE_ID_LOGITECH_WHEEL && !lg4ff_no_autoswitch) {
hid_info(hid, "\"%s\" cannot be switched to \"DF-EX\" mode. Load the \"hid_logitech\" module with \"lg4ff_no_autoswitch=1\" parameter set and try again\n",
entry->real_name);
return -EINVAL;
}

/* Take care of hardware limitations */
if ((entry->real_product_id == USB_DEVICE_ID_LOGITECH_DFP_WHEEL || entry->real_product_id == USB_DEVICE_ID_LOGITECH_G25_WHEEL) &&
entry->product_id > target_product_id) {
hid_info(hid, "\"%s\" cannot be switched back into \"%s\" mode\n", entry->real_name, lg4ff_alternate_modes[i].name);
return -EINVAL;
}

s = lg4ff_get_mode_switch_command(entry->real_product_id, target_product_id);
if (!s) {
hid_err(hid, "Invalid target product ID %X\n", target_product_id);
return -EINVAL;
}

ret = lg4ff_switch_compatibility_mode(hid, s);
return (ret == 0 ? count : ret);
}
static DEVICE_ATTR(alternate_modes, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH, lg4ff_alternate_modes_show, lg4ff_alternate_modes_store);

Expand Down Expand Up @@ -783,7 +941,8 @@ static u16 lg4ff_identify_multimode_wheel(struct hid_device *hid, const u16 repo
}
}

/* No match found. This is an unknown wheel model, do not touch it */
/* No match found. This is either Driving Force or an unknown
* wheel model, do not touch it */
dbg_hid("Wheel with bcdDevice %X was not recognized as multimode wheel, leaving in its current mode\n", bcdDevice);
return 0;
}
Expand All @@ -806,22 +965,9 @@ static int lg4ff_handle_multimode_wheel(struct hid_device *hid, u16 *real_produc
if (reported_product_id == USB_DEVICE_ID_LOGITECH_WHEEL &&
reported_product_id != *real_product_id &&
!lg4ff_no_autoswitch) {
const struct lg4ff_compat_mode_switch *s;
const struct lg4ff_compat_mode_switch *s = lg4ff_get_mode_switch_command(*real_product_id, *real_product_id);

switch (*real_product_id) {
case USB_DEVICE_ID_LOGITECH_DFP_WHEEL:
s = &lg4ff_mode_switch_dfp;
break;
case USB_DEVICE_ID_LOGITECH_G25_WHEEL:
s = &lg4ff_mode_switch_g25;
break;
case USB_DEVICE_ID_LOGITECH_G27_WHEEL:
s = &lg4ff_mode_switch_g27;
break;
case USB_DEVICE_ID_LOGITECH_DFGT_WHEEL:
s = &lg4ff_mode_switch_dfgt;
break;
default:
if (!s) {
hid_err(hid, "Invalid product id %X\n", *real_product_id);
return LG4FF_MMODE_NOT_MULTIMODE;
}
Expand Down

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