4 files changed, 287 insertions, 89 deletions

diff --git a/drivers/hid/hid-lg.c b/drivers/hid/hid-lg.c
index e7a7bd1eb34a..fc37ed6b108c 100644
--- a/drivers/hid/hid-lg.c
+++ b/drivers/hid/hid-lg.c
@@ -109,23 +109,23 @@ static __u8 dfp_rdesc_fixed[] = {
 static __u8 *lg_report_fixup(struct hid_device *hdev, __u8 *rdesc,
                 unsigned int *rsize)
 {
-        unsigned long quirks = (unsigned long)hid_get_drvdata(hdev);
+        struct lg_drv_data *drv_data = (struct lg_drv_data *)hid_get_drvdata(hdev);
 
-        if ((quirks & LG_RDESC) && *rsize >= 90 && rdesc[83] == 0x26 &&
+        if ((drv_data->quirks & LG_RDESC) && *rsize >= 90 && rdesc[83] == 0x26 &&
                         rdesc[84] == 0x8c && rdesc[85] == 0x02) {
                 hid_info(hdev,
                          "fixing up Logitech keyboard report descriptor\n");
                 rdesc[84] = rdesc[89] = 0x4d;
                 rdesc[85] = rdesc[90] = 0x10;
         }
-        if ((quirks & LG_RDESC_REL_ABS) && *rsize >= 50 &&
+        if ((drv_data->quirks & LG_RDESC_REL_ABS) && *rsize >= 50 &&
                         rdesc[32] == 0x81 && rdesc[33] == 0x06 &&
                         rdesc[49] == 0x81 && rdesc[50] == 0x06) {
                 hid_info(hdev,
                          "fixing up rel/abs in Logitech report descriptor\n");
                 rdesc[33] = rdesc[50] = 0x02;
         }
-        if ((quirks & LG_FF4) && *rsize >= 101 &&
+        if ((drv_data->quirks & LG_FF4) && *rsize >= 101 &&
                         rdesc[41] == 0x95 && rdesc[42] == 0x0B &&
                         rdesc[47] == 0x05 && rdesc[48] == 0x09) {
                 hid_info(hdev, "fixing up Logitech Speed Force Wireless button descriptor\n");
@@ -278,7 +278,7 @@ static int lg_input_mapping(struct hid_device *hdev, struct hid_input *hi,
                   0,  0,  0,  0,  0,183,184,185,186,187,
                 188,189,190,191,192,193,194,  0,  0,  0
         };
-        unsigned long quirks = (unsigned long)hid_get_drvdata(hdev);
+        struct lg_drv_data *drv_data = (struct lg_drv_data *)hid_get_drvdata(hdev);
         unsigned int hid = usage->hid;
 
         if (hdev->product == USB_DEVICE_ID_LOGITECH_RECEIVER &&
@@ -289,7 +289,7 @@ static int lg_input_mapping(struct hid_device *hdev, struct hid_input *hi,
                         lg_dinovo_mapping(hi, usage, bit, max))
                 return 1;
 
-        if ((quirks & LG_WIRELESS) && lg_wireless_mapping(hi, usage, bit, max))
+        if ((drv_data->quirks & LG_WIRELESS) && lg_wireless_mapping(hi, usage, bit, max))
                 return 1;
 
         if ((hid & HID_USAGE_PAGE) != HID_UP_BUTTON)
@@ -299,11 +299,11 @@ static int lg_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 
         /* Special handling for Logitech Cordless Desktop */
         if (field->application == HID_GD_MOUSE) {
-                if ((quirks & LG_IGNORE_DOUBLED_WHEEL) &&
+                if ((drv_data->quirks & LG_IGNORE_DOUBLED_WHEEL) &&
                                 (hid == 7 || hid == 8))
                         return -1;
         } else {
-                if ((quirks & LG_EXPANDED_KEYMAP) &&
+                if ((drv_data->quirks & LG_EXPANDED_KEYMAP) &&
                                 hid < ARRAY_SIZE(e_keymap) &&
                                 e_keymap[hid] != 0) {
                         hid_map_usage(hi, usage, bit, max, EV_KEY,
@@ -319,13 +319,13 @@ static int lg_input_mapped(struct hid_device *hdev, struct hid_input *hi,
                 struct hid_field *field, struct hid_usage *usage,
                 unsigned long **bit, int *max)
 {
-        unsigned long quirks = (unsigned long)hid_get_drvdata(hdev);
+        struct lg_drv_data *drv_data = (struct lg_drv_data *)hid_get_drvdata(hdev);
 
-        if ((quirks & LG_BAD_RELATIVE_KEYS) && usage->type == EV_KEY &&
+        if ((drv_data->quirks & LG_BAD_RELATIVE_KEYS) && usage->type == EV_KEY &&
                         (field->flags & HID_MAIN_ITEM_RELATIVE))
                 field->flags &= ~HID_MAIN_ITEM_RELATIVE;
 
-        if ((quirks & LG_DUPLICATE_USAGES) && (usage->type == EV_KEY ||
+        if ((drv_data->quirks & LG_DUPLICATE_USAGES) && (usage->type == EV_KEY ||
                          usage->type == EV_REL || usage->type == EV_ABS))
                 clear_bit(usage->code, *bit);
 
@@ -335,9 +335,9 @@ static int lg_input_mapped(struct hid_device *hdev, struct hid_input *hi,
 static int lg_event(struct hid_device *hdev, struct hid_field *field,
                 struct hid_usage *usage, __s32 value)
 {
-        unsigned long quirks = (unsigned long)hid_get_drvdata(hdev);
+        struct lg_drv_data *drv_data = (struct lg_drv_data *)hid_get_drvdata(hdev);
 
-        if ((quirks & LG_INVERT_HWHEEL) && usage->code == REL_HWHEEL) {
+        if ((drv_data->quirks & LG_INVERT_HWHEEL) && usage->code == REL_HWHEEL) {
                 input_event(field->hidinput->input, usage->type, usage->code,
                                 -value);
                 return 1;
@@ -348,13 +348,20 @@ static int lg_event(struct hid_device *hdev, struct hid_field *field,
 
 static int lg_probe(struct hid_device *hdev, const struct hid_device_id *id)
 {
-        unsigned long quirks = id->driver_data;
         unsigned int connect_mask = HID_CONNECT_DEFAULT;
+        struct lg_drv_data *drv_data;
         int ret;
 
-        hid_set_drvdata(hdev, (void *)quirks);
+        drv_data = kzalloc(sizeof(struct lg_drv_data), GFP_KERNEL);
+        if (!drv_data) {
+                hid_err(hdev, "Insufficient memory, cannot allocate driver data\n");
+                return -ENOMEM;
+        }
+        drv_data->quirks = id->driver_data;
+        
+        hid_set_drvdata(hdev, (void *)drv_data);
 
-        if (quirks & LG_NOGET)
+        if (drv_data->quirks & LG_NOGET)
                 hdev->quirks |= HID_QUIRK_NOGET;
 
         ret = hid_parse(hdev);
@@ -363,7 +370,7 @@ static int lg_probe(struct hid_device *hdev, const struct hid_device_id *id)
                 goto err_free;
         }
 
-        if (quirks & (LG_FF | LG_FF2 | LG_FF3 | LG_FF4))
+        if (drv_data->quirks & (LG_FF | LG_FF2 | LG_FF3 | LG_FF4))
                 connect_mask &= ~HID_CONNECT_FF;
 
         ret = hid_hw_start(hdev, connect_mask);
@@ -392,27 +399,29 @@ static int lg_probe(struct hid_device *hdev, const struct hid_device_id *id)
                 }
         }
 
-        if (quirks & LG_FF)
+        if (drv_data->quirks & LG_FF)
                 lgff_init(hdev);
-        if (quirks & LG_FF2)
+        if (drv_data->quirks & LG_FF2)
                 lg2ff_init(hdev);
-        if (quirks & LG_FF3)
+        if (drv_data->quirks & LG_FF3)
                 lg3ff_init(hdev);
-        if (quirks & LG_FF4)
+        if (drv_data->quirks & LG_FF4)
                 lg4ff_init(hdev);
 
         return 0;
 err_free:
+        kfree(drv_data);
         return ret;
 }
 
 static void lg_remove(struct hid_device *hdev)
 {
-        unsigned long quirks = (unsigned long)hid_get_drvdata(hdev);
-        if(quirks & LG_FF4)
+        struct lg_drv_data *drv_data = (struct lg_drv_data *)hid_get_drvdata(hdev);
+        if (drv_data->quirks & LG_FF4)
                 lg4ff_deinit(hdev);
 
         hid_hw_stop(hdev);
+        kfree(drv_data);
 }
 
 static const struct hid_device_id lg_devices[] = {
diff --git a/drivers/hid/hid-lg.h b/drivers/hid/hid-lg.h
index 4b097286dc78..d64cf8d2751e 100644
--- a/drivers/hid/hid-lg.h
+++ b/drivers/hid/hid-lg.h
@@ -1,6 +1,11 @@
 #ifndef __HID_LG_H
 #define __HID_LG_H
 
+struct lg_drv_data {
+        unsigned long quirks;
+        void *device_props;     /* Device specific properties */
+};
+
 #ifdef CONFIG_LOGITECH_FF
 int lgff_init(struct hid_device *hdev);
 #else
diff --git a/drivers/hid/hid-lg4ff.c b/drivers/hid/hid-lg4ff.c
index 6ecc9e220440..f3390ee6105c 100644
--- a/drivers/hid/hid-lg4ff.c
+++ b/drivers/hid/hid-lg4ff.c
@@ -1,7 +1,8 @@
 /*
- *  Force feedback support for Logitech Speed Force Wireless
+ *  Force feedback support for Logitech Gaming Wheels
  *
- *  http://wiibrew.org/wiki/Logitech_USB_steering_wheel
+ *  Including G27, G25, DFP, DFGT, FFEX, Momo, Momo2 &
+ *  Speed Force Wireless (WiiWheel)
  *
  *  Copyright (c) 2010 Simon Wood <simon@mungewell.org>
  */
@@ -51,20 +52,18 @@ static ssize_t lg4ff_range_store(struct device *dev, struct device_attribute *at
 
 static DEVICE_ATTR(range, S_IRWXU | S_IRWXG | S_IRWXO, lg4ff_range_show, lg4ff_range_store);
 
-static bool list_inited;
-
 struct lg4ff_device_entry {
-        char  *device_id;       /* Use name in respective kobject structure's address as the ID */
         __u16 range;
         __u16 min_range;
         __u16 max_range;
-        __u8  leds;
+#ifdef CONFIG_LEDS_CLASS
+        __u8  led_state;
+        struct led_classdev *led[5];
+#endif
         struct list_head list;
         void (*set_range)(struct hid_device *hid, u16 range);
 };
 
-static struct lg4ff_device_entry device_list;
-
 static const signed short lg4ff_wheel_effects[] = {
         FF_CONSTANT,
         FF_AUTOCENTER,
@@ -285,18 +284,20 @@ static void hid_lg4ff_switch_native(struct hid_device *hid, const struct lg4ff_n
 /* Read current range and display it in terminal */
 static ssize_t lg4ff_range_show(struct device *dev, struct device_attribute *attr, char *buf)
 {
-        struct lg4ff_device_entry *uninitialized_var(entry);
-        struct list_head *h;
         struct hid_device *hid = to_hid_device(dev);
+        struct lg4ff_device_entry *entry;
+        struct lg_drv_data *drv_data;
         size_t count;
 
-        list_for_each(h, &device_list.list) {
-                entry = list_entry(h, struct lg4ff_device_entry, list);
-                if (strcmp(entry->device_id, (&hid->dev)->kobj.name) == 0)
-                        break;
+        drv_data = hid_get_drvdata(hid);
+        if (!drv_data) {
+                hid_err(hid, "Private driver data not found!\n");
+                return 0;
         }
-        if (h == &device_list.list) {
-                dbg_hid("Device not found!");
+
+        entry = drv_data->device_props;
+        if (!entry) {
+                hid_err(hid, "Device properties not found!\n");
                 return 0;
         }
 
@@ -308,19 +309,21 @@ static ssize_t lg4ff_range_show(struct device *dev, struct device_attribute *att
  * according to the type of the wheel */
 static ssize_t lg4ff_range_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 {
-        struct lg4ff_device_entry *uninitialized_var(entry);
-        struct list_head *h;
         struct hid_device *hid = to_hid_device(dev);
+        struct lg4ff_device_entry *entry;
+        struct lg_drv_data *drv_data;
         __u16 range = simple_strtoul(buf, NULL, 10);
 
-        list_for_each(h, &device_list.list) {
-                entry = list_entry(h, struct lg4ff_device_entry, list);
-                if (strcmp(entry->device_id, (&hid->dev)->kobj.name) == 0)
-                        break;
+        drv_data = hid_get_drvdata(hid);
+        if (!drv_data) {
+                hid_err(hid, "Private driver data not found!\n");
+                return 0;
         }
-        if (h == &device_list.list) {
-                dbg_hid("Device not found!");
-                return count;
+
+        entry = drv_data->device_props;
+        if (!entry) {
+                hid_err(hid, "Device properties not found!\n");
+                return 0;
         }
 
         if (range == 0)
@@ -336,6 +339,88 @@ static ssize_t lg4ff_range_store(struct device *dev, struct device_attribute *at
         return count;
 }
 
+#ifdef CONFIG_LEDS_CLASS
+static void lg4ff_set_leds(struct hid_device *hid, __u8 leds)
+{
+        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);
+
+        report->field[0]->value[0] = 0xf8;
+        report->field[0]->value[1] = 0x12;
+        report->field[0]->value[2] = leds;
+        report->field[0]->value[3] = 0x00;
+        report->field[0]->value[4] = 0x00;
+        report->field[0]->value[5] = 0x00;
+        report->field[0]->value[6] = 0x00;
+        usbhid_submit_report(hid, report, USB_DIR_OUT);
+}
+
+static void lg4ff_led_set_brightness(struct led_classdev *led_cdev,
+                        enum led_brightness value)
+{
+        struct device *dev = led_cdev->dev->parent;
+        struct hid_device *hid = container_of(dev, struct hid_device, dev);
+        struct lg_drv_data *drv_data = (struct lg_drv_data *)hid_get_drvdata(hid);
+        struct lg4ff_device_entry *entry;
+        int i, state = 0;
+
+        if (!drv_data) {
+                hid_err(hid, "Device data not found.");
+                return;
+        }
+
+        entry = (struct lg4ff_device_entry *)drv_data->device_props;
+
+        if (!entry) {
+                hid_err(hid, "Device properties not found.");
+                return;
+        }
+
+        for (i = 0; i < 5; i++) {
+                if (led_cdev != entry->led[i])
+                        continue;
+                state = (entry->led_state >> i) & 1;
+                if (value == LED_OFF && state) {
+                        entry->led_state &= ~(1 << i);
+                        lg4ff_set_leds(hid, entry->led_state);
+                } else if (value != LED_OFF && !state) {
+                        entry->led_state |= 1 << i;
+                        lg4ff_set_leds(hid, entry->led_state);
+                }
+                break;
+        }
+}
+
+static enum led_brightness lg4ff_led_get_brightness(struct led_classdev *led_cdev)
+{
+        struct device *dev = led_cdev->dev->parent;
+        struct hid_device *hid = container_of(dev, struct hid_device, dev);
+        struct lg_drv_data *drv_data = (struct lg_drv_data *)hid_get_drvdata(hid);
+        struct lg4ff_device_entry *entry;
+        int i, value = 0;
+
+        if (!drv_data) {
+                hid_err(hid, "Device data not found.");
+                return LED_OFF;
+        }
+
+        entry = (struct lg4ff_device_entry *)drv_data->device_props;
+
+        if (!entry) {
+                hid_err(hid, "Device properties not found.");
+                return LED_OFF;
+        }
+
+        for (i = 0; i < 5; i++)
+                if (led_cdev == entry->led[i]) {
+                        value = (entry->led_state >> i) & 1;
+                        break;
+                }
+
+        return value ? LED_FULL : LED_OFF;
+}
+#endif
+
 int lg4ff_init(struct hid_device *hid)
 {
         struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list);
@@ -344,6 +429,7 @@ int lg4ff_init(struct hid_device *hid)
         struct hid_report *report;
         struct hid_field *field;
         struct lg4ff_device_entry *entry;
+        struct lg_drv_data *drv_data;
         struct usb_device_descriptor *udesc;
         int error, i, j;
         __u16 bcdDevice, rev_maj, rev_min;
@@ -423,28 +509,24 @@ int lg4ff_init(struct hid_device *hid)
                 dev->ff->set_autocenter(dev, 0);
         }
 
-                /* Initialize device_list if this is the first device to handle by lg4ff */
-        if (!list_inited) {
-                INIT_LIST_HEAD(&device_list.list);
-                list_inited = 1;
+        /* Get private driver data */
+        drv_data = hid_get_drvdata(hid);
+        if (!drv_data) {
+                hid_err(hid, "Cannot add device, private driver data not allocated\n");
+                return -1;
         }
 
-        /* Add the device to device_list */
+        /* Initialize device properties */
         entry = kzalloc(sizeof(struct lg4ff_device_entry), GFP_KERNEL);
         if (!entry) {
-                hid_err(hid, "Cannot add device, insufficient memory.\n");
-                return -ENOMEM;
-        }
-        entry->device_id = kstrdup((&hid->dev)->kobj.name, GFP_KERNEL);
-        if (!entry->device_id) {
-                hid_err(hid, "Cannot set device_id, insufficient memory.\n");
-                kfree(entry);
+                hid_err(hid, "Cannot add device, insufficient memory to allocate device properties.\n");
                 return -ENOMEM;
         }
+        drv_data->device_props = entry;
+
         entry->min_range = lg4ff_devices[i].min_range;
         entry->max_range = lg4ff_devices[i].max_range;
         entry->set_range = lg4ff_devices[i].set_range;
-        list_add(&entry->list, &device_list.list);
 
         /* Create sysfs interface */
         error = device_create_file(&hid->dev, &dev_attr_range);
@@ -457,32 +539,100 @@ int lg4ff_init(struct hid_device *hid)
         if (entry->set_range != NULL)
                 entry->set_range(hid, entry->range);
 
-        hid_info(hid, "Force feedback for Logitech Speed Force Wireless by Simon Wood <simon@mungewell.org>\n");
+#ifdef CONFIG_LEDS_CLASS
+        /* register led subsystem - G27 only */
+        entry->led_state = 0;
+        for (j = 0; j < 5; j++)
+                entry->led[j] = NULL;
+
+        if (lg4ff_devices[i].product_id == USB_DEVICE_ID_LOGITECH_G27_WHEEL) {
+                struct led_classdev *led;
+                size_t name_sz;
+                char *name;
+
+                lg4ff_set_leds(hid, 0);
+
+                name_sz = strlen(dev_name(&hid->dev)) + 8;
+
+                for (j = 0; j < 5; j++) {
+                        led = kzalloc(sizeof(struct led_classdev)+name_sz, GFP_KERNEL);
+                        if (!led) {
+                                hid_err(hid, "can't allocate memory for LED %d\n", j);
+                                goto err;
+                        }
+
+                        name = (void *)(&led[1]);
+                        snprintf(name, name_sz, "%s::RPM%d", dev_name(&hid->dev), j+1);
+                        led->name = name;
+                        led->brightness = 0;
+                        led->max_brightness = 1;
+                        led->brightness_get = lg4ff_led_get_brightness;
+                        led->brightness_set = lg4ff_led_set_brightness;
+
+                        entry->led[j] = led;
+                        error = led_classdev_register(&hid->dev, led);
+
+                        if (error) {
+                                hid_err(hid, "failed to register LED %d. Aborting.\n", j);
+err:
+                                /* Deregister LEDs (if any) */
+                                for (j = 0; j < 5; j++) {
+                                        led = entry->led[j];
+                                        entry->led[j] = NULL;
+                                        if (!led)
+                                                continue;
+                                        led_classdev_unregister(led);
+                                        kfree(led);
+                                }
+                                goto out;       /* Let the driver continue without LEDs */
+                        }
+                }
+        }
+out:
+#endif
+        hid_info(hid, "Force feedback support for Logitech Gaming Wheels\n");
         return 0;
 }
 
 int lg4ff_deinit(struct hid_device *hid)
 {
-        bool found = 0;
         struct lg4ff_device_entry *entry;
-        struct list_head *h, *g;
-        list_for_each_safe(h, g, &device_list.list) {
-                entry = list_entry(h, struct lg4ff_device_entry, list);
-                if (strcmp(entry->device_id, (&hid->dev)->kobj.name) == 0) {
-                        list_del(h);
-                        kfree(entry->device_id);
-                        kfree(entry);
-                        found = 1;
-                        break;
-                }
-        }
+        struct lg_drv_data *drv_data;
+
+        device_remove_file(&hid->dev, &dev_attr_range);
 
-        if (!found) {
-                dbg_hid("Device entry not found!\n");
+        drv_data = hid_get_drvdata(hid);
+        if (!drv_data) {
+                hid_err(hid, "Error while deinitializing device, no private driver data.\n");
+                return -1;
+        }
+        entry = drv_data->device_props;
+        if (!entry) {
+                hid_err(hid, "Error while deinitializing device, no device properties data.\n");
                 return -1;
         }
 
-        device_remove_file(&hid->dev, &dev_attr_range);
+#ifdef CONFIG_LEDS_CLASS
+        {
+                int j;
+                struct led_classdev *led;
+
+                /* Deregister LEDs (if any) */
+                for (j = 0; j < 5; j++) {
+
+                        led = entry->led[j];
+                        entry->led[j] = NULL;
+                        if (!led)
+                                continue;
+                        led_classdev_unregister(led);
+                        kfree(led);
+                }
+        }
+#endif
+
+        /* Deallocate memory */
+        kfree(entry);
+
         dbg_hid("Device successfully unregistered\n");
         return 0;
 }
diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index 25b94253e68f..6e3332a99976 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -70,9 +70,16 @@ struct mt_class {
         bool is_indirect;       /* true for touchpads */
 };
 
+struct mt_fields {
+        unsigned usages[HID_MAX_FIELDS];
+        unsigned int length;
+};
+
 struct mt_device {
         struct mt_slot curdata; /* placeholder of incoming data */
         struct mt_class mtclass;        /* our mt device class */
+        struct mt_fields *fields;       /* temporary placeholder for storing the
+                                           multitouch fields */
         unsigned last_field_index;      /* last field index of the report */
         unsigned last_slot_field;       /* the last field of a slot */
         __s8 inputmode;         /* InputMode HID feature, -1 if non-existent */
@@ -278,11 +285,15 @@ static void set_abs(struct input_dev *input, unsigned int code,
         input_set_abs_params(input, code, fmin, fmax, fuzz, 0);
 }
 
-static void set_last_slot_field(struct hid_usage *usage, struct mt_device *td,
+static void mt_store_field(struct hid_usage *usage, struct mt_device *td,
                 struct hid_input *hi)
 {
-        if (!test_bit(usage->hid, hi->input->absbit))
-                td->last_slot_field = usage->hid;
+        struct mt_fields *f = td->fields;
+
+        if (f->length >= HID_MAX_FIELDS)
+                return;
+
+        f->usages[f->length++] = usage->hid;
 }
 
 static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
@@ -333,7 +344,7 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
                                 cls->sn_move);
                         /* touchscreen emulation */
                         set_abs(hi->input, ABS_X, field, cls->sn_move);
-                        set_last_slot_field(usage, td, hi);
+                        mt_store_field(usage, td, hi);
                         td->last_field_index = field->index;
                         return 1;
                 case HID_GD_Y:
@@ -343,7 +354,7 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
                                 cls->sn_move);
                         /* touchscreen emulation */
                         set_abs(hi->input, ABS_Y, field, cls->sn_move);
-                        set_last_slot_field(usage, td, hi);
+                        mt_store_field(usage, td, hi);
                         td->last_field_index = field->index;
                         return 1;
                 }
@@ -352,24 +363,24 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
         case HID_UP_DIGITIZER:
                 switch (usage->hid) {
                 case HID_DG_INRANGE:
-                        set_last_slot_field(usage, td, hi);
+                        mt_store_field(usage, td, hi);
                         td->last_field_index = field->index;
                         return 1;
                 case HID_DG_CONFIDENCE:
-                        set_last_slot_field(usage, td, hi);
+                        mt_store_field(usage, td, hi);
                         td->last_field_index = field->index;
                         return 1;
                 case HID_DG_TIPSWITCH:
                         hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
                         input_set_capability(hi->input, EV_KEY, BTN_TOUCH);
-                        set_last_slot_field(usage, td, hi);
+                        mt_store_field(usage, td, hi);
                         td->last_field_index = field->index;
                         return 1;
                 case HID_DG_CONTACTID:
                         if (!td->maxcontacts)
                                 td->maxcontacts = MT_DEFAULT_MAXCONTACT;
                         input_mt_init_slots(hi->input, td->maxcontacts);
-                        td->last_slot_field = usage->hid;
+                        mt_store_field(usage, td, hi);
                         td->last_field_index = field->index;
                         td->touches_by_report++;
                         return 1;
@@ -378,7 +389,7 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
                                         EV_ABS, ABS_MT_TOUCH_MAJOR);
                         set_abs(hi->input, ABS_MT_TOUCH_MAJOR, field,
                                 cls->sn_width);
-                        set_last_slot_field(usage, td, hi);
+                        mt_store_field(usage, td, hi);
                         td->last_field_index = field->index;
                         return 1;
                 case HID_DG_HEIGHT:
@@ -388,7 +399,7 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
                                 cls->sn_height);
                         input_set_abs_params(hi->input,
                                         ABS_MT_ORIENTATION, 0, 1, 0, 0);
-                        set_last_slot_field(usage, td, hi);
+                        mt_store_field(usage, td, hi);
                         td->last_field_index = field->index;
                         return 1;
                 case HID_DG_TIPPRESSURE:
@@ -399,7 +410,7 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
                         /* touchscreen emulation */
                         set_abs(hi->input, ABS_PRESSURE, field,
                                 cls->sn_pressure);
-                        set_last_slot_field(usage, td, hi);
+                        mt_store_field(usage, td, hi);
                         td->last_field_index = field->index;
                         return 1;
                 case HID_DG_CONTACTCOUNT:
@@ -653,6 +664,16 @@ static void mt_post_parse_default_settings(struct mt_device *td)
         td->mtclass.quirks = quirks;
 }
 
+static void mt_post_parse(struct mt_device *td)
+{
+        struct mt_fields *f = td->fields;
+
+        if (td->touches_by_report > 0) {
+                int field_count_per_touch = f->length / td->touches_by_report;
+                td->last_slot_field = f->usages[field_count_per_touch - 1];
+        }
+}
+
 static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
 {
         int ret, i;
@@ -683,6 +704,13 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
         td->maxcontact_report_id = -1;
         hid_set_drvdata(hdev, td);
 
+        td->fields = kzalloc(sizeof(struct mt_fields), GFP_KERNEL);
+        if (!td->fields) {
+                dev_err(&hdev->dev, "cannot allocate multitouch fields data\n");
+                ret = -ENOMEM;
+                goto fail;
+        }
+
         ret = hid_parse(hdev);
         if (ret != 0)
                 goto fail;
@@ -691,6 +719,8 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
         if (ret)
                 goto fail;
 
+        mt_post_parse(td);
+
         if (id->vendor == HID_ANY_ID && id->product == HID_ANY_ID)
                 mt_post_parse_default_settings(td);
 
@@ -708,9 +738,13 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
         mt_set_maxcontacts(hdev);
         mt_set_input_mode(hdev);
 
+        kfree(td->fields);
+        td->fields = NULL;
+
         return 0;
 
 fail:
+        kfree(td->fields);
         kfree(td);
         return ret;
 }