[PATCH v3 4/4] HID: hid-lg4ff: Allow switching of Logitech gaming wheels between available compatibility modes through sysfs. This only applies to multimode wheels.

From: Michal MalÃ
Date: Wed Feb 18 2015 - 12:01:05 EST

Next message: Petr Mladek: "[PATCH] livepatch: RCU protect struct klp_func all the time when used in klp_ftrace_handler()"
Previous message: Ingo Molnar: "Re: [GIT PULL rcu/next] One more RCU commit for 3.20"
In reply to: Michal MalÃ: "[PATCH v3 1/4] HID: hid-lg4ff: Identify Logitech gaming wheels in compatibility modes accordingly to Logitech specifications"
Next in thread: Jiri Kosina: "Re: [PATCH v3 0/4] HID: hid-lg4ff: Improve handling of Logitech multimode wheels"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

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

Signed-off-by: Michal MalÃ <madcatxster@xxxxxxxxxxxxxxxxxx>
---
v2: Fix a misleading error message regarding unsupported wheel mode

.../ABI/testing/sysfs-driver-hid-logitech-lg4ff | 27 ++-
drivers/hid/hid-lg4ff.c | 204 ++++++++++++++++++---
2 files changed, 201 insertions(+), 30 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-driver-hid-logitech-lg4ff b/Documentation/ABI/testing/sysfs-driver-hid-logitech-lg4ff
index 60f24a1..b3f6a2a 100644
--- a/Documentation/ABI/testing/sysfs-driver-hid-logitech-lg4ff
+++ b/Documentation/ABI/testing/sysfs-driver-hid-logitech-lg4ff
@@ -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
diff --git a/drivers/hid/hid-lg4ff.c b/drivers/hid/hid-lg4ff.c
index dd30772..854982b 100644
--- a/drivers/hid/hid-lg4ff.c
+++ b/drivers/hid/hid-lg4ff.c
@@ -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 */
@@ -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);
@@ -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);

@@ -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;
}
@@ -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;
}
--
2.3.0

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

Next message: Petr Mladek: "[PATCH] livepatch: RCU protect struct klp_func all the time when used in klp_ftrace_handler()"
Previous message: Ingo Molnar: "Re: [GIT PULL rcu/next] One more RCU commit for 3.20"
In reply to: Michal MalÃ: "[PATCH v3 1/4] HID: hid-lg4ff: Identify Logitech gaming wheels in compatibility modes accordingly to Logitech specifications"
Next in thread: Jiri Kosina: "Re: [PATCH v3 0/4] HID: hid-lg4ff: Improve handling of Logitech multimode wheels"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]