HID: logitech-dj: allow transfer of HID++ reports from/to the correct dj device
authorBenjamin Tissoires <benjamin.tissoires@redhat.com>
Tue, 30 Sep 2014 17:18:29 +0000 (13:18 -0400)
committerJiri Kosina <jkosina@suse.cz>
Wed, 29 Oct 2014 09:51:40 +0000 (10:51 +0100)
HID++ is a Logitech-specific protocol for communicating with HID
devices. DJ devices implement HID++, and so we can add the HID++
collection in the report descriptor and forward the incoming
reports from the receiver to the appropriate DJ device.

The same can be done in the other way, if someone calls a
.raw_request(), we can forward it to the correct dj device
by overriding the device_index in the HID++ report.

Signed-off-by: Benjamin Tisssoires <benjamin.tissoires@redhat.com>
Tested-by: Andrew de los Reyes <adlr@chromium.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
drivers/hid/hid-logitech-dj.c

index 45a7eac..feddacd 100644 (file)
 #define REPORT_ID_DJ_SHORT                     0x20
 #define REPORT_ID_DJ_LONG                      0x21
 
+#define REPORT_ID_HIDPP_SHORT                  0x10
+#define REPORT_ID_HIDPP_LONG                   0x11
+
+#define HIDPP_REPORT_SHORT_LENGTH              7
+#define HIDPP_REPORT_LONG_LENGTH               20
+
+#define HIDPP_RECEIVER_INDEX                   0xff
+
+#define REPORT_TYPE_RFREPORT_FIRST             0x01
 #define REPORT_TYPE_RFREPORT_LAST              0x1F
 
 /* Command Switch to DJ mode */
@@ -242,6 +251,57 @@ static const char media_descriptor[] = {
        0xc0,                   /* EndCollection                       */
 };                             /*                                     */
 
+/* HIDPP descriptor */
+static const char hidpp_descriptor[] = {
+       0x06, 0x00, 0xff,       /* Usage Page (Vendor Defined Page 1)  */
+       0x09, 0x01,             /* Usage (Vendor Usage 1)              */
+       0xa1, 0x01,             /* Collection (Application)            */
+       0x85, 0x10,             /*   Report ID (16)                    */
+       0x75, 0x08,             /*   Report Size (8)                   */
+       0x95, 0x06,             /*   Report Count (6)                  */
+       0x15, 0x00,             /*   Logical Minimum (0)               */
+       0x26, 0xff, 0x00,       /*   Logical Maximum (255)             */
+       0x09, 0x01,             /*   Usage (Vendor Usage 1)            */
+       0x81, 0x00,             /*   Input (Data,Arr,Abs)              */
+       0x09, 0x01,             /*   Usage (Vendor Usage 1)            */
+       0x91, 0x00,             /*   Output (Data,Arr,Abs)             */
+       0xc0,                   /* End Collection                      */
+       0x06, 0x00, 0xff,       /* Usage Page (Vendor Defined Page 1)  */
+       0x09, 0x02,             /* Usage (Vendor Usage 2)              */
+       0xa1, 0x01,             /* Collection (Application)            */
+       0x85, 0x11,             /*   Report ID (17)                    */
+       0x75, 0x08,             /*   Report Size (8)                   */
+       0x95, 0x13,             /*   Report Count (19)                 */
+       0x15, 0x00,             /*   Logical Minimum (0)               */
+       0x26, 0xff, 0x00,       /*   Logical Maximum (255)             */
+       0x09, 0x02,             /*   Usage (Vendor Usage 2)            */
+       0x81, 0x00,             /*   Input (Data,Arr,Abs)              */
+       0x09, 0x02,             /*   Usage (Vendor Usage 2)            */
+       0x91, 0x00,             /*   Output (Data,Arr,Abs)             */
+       0xc0,                   /* End Collection                      */
+       0x06, 0x00, 0xff,       /* Usage Page (Vendor Defined Page 1)  */
+       0x09, 0x04,             /* Usage (Vendor Usage 0x04)           */
+       0xa1, 0x01,             /* Collection (Application)            */
+       0x85, 0x20,             /*   Report ID (32)                    */
+       0x75, 0x08,             /*   Report Size (8)                   */
+       0x95, 0x0e,             /*   Report Count (14)                 */
+       0x15, 0x00,             /*   Logical Minimum (0)               */
+       0x26, 0xff, 0x00,       /*   Logical Maximum (255)             */
+       0x09, 0x41,             /*   Usage (Vendor Usage 0x41)         */
+       0x81, 0x00,             /*   Input (Data,Arr,Abs)              */
+       0x09, 0x41,             /*   Usage (Vendor Usage 0x41)         */
+       0x91, 0x00,             /*   Output (Data,Arr,Abs)             */
+       0x85, 0x21,             /*   Report ID (33)                    */
+       0x95, 0x1f,             /*   Report Count (31)                 */
+       0x15, 0x00,             /*   Logical Minimum (0)               */
+       0x26, 0xff, 0x00,       /*   Logical Maximum (255)             */
+       0x09, 0x42,             /*   Usage (Vendor Usage 0x42)         */
+       0x81, 0x00,             /*   Input (Data,Arr,Abs)              */
+       0x09, 0x42,             /*   Usage (Vendor Usage 0x42)         */
+       0x91, 0x00,             /*   Output (Data,Arr,Abs)             */
+       0xc0,                   /* End Collection                      */
+};
+
 /* Maximum size of all defined hid reports in bytes (including report id) */
 #define MAX_REPORT_SIZE 8
 
@@ -251,7 +311,8 @@ static const char media_descriptor[] = {
         sizeof(mse_descriptor) +               \
         sizeof(consumer_descriptor) +          \
         sizeof(syscontrol_descriptor) +        \
-        sizeof(media_descriptor))
+        sizeof(media_descriptor) +     \
+        sizeof(hidpp_descriptor))
 
 /* Number of possible hid report types that can be created by this driver.
  *
@@ -512,6 +573,13 @@ static void logi_dj_recv_forward_report(struct dj_receiver_dev *djrcv_dev,
        }
 }
 
+static void logi_dj_recv_forward_hidpp(struct dj_device *dj_dev, u8 *data,
+                                      int size)
+{
+       /* We are called from atomic context (tasklet && djrcv->lock held) */
+       if (hid_input_report(dj_dev->hdev, HID_INPUT_REPORT, data, size, 1))
+               dbg_hid("hid_input_report error\n");
+}
 
 static int logi_dj_recv_send_report(struct dj_receiver_dev *djrcv_dev,
                                    struct dj_report *dj_report)
@@ -609,6 +677,16 @@ static int logi_dj_ll_raw_request(struct hid_device *hid,
        u8 *out_buf;
        int ret;
 
+       if ((buf[0] == REPORT_ID_HIDPP_SHORT) ||
+           (buf[0] == REPORT_ID_HIDPP_LONG)) {
+               if (count < 2)
+                       return -EINVAL;
+
+               buf[1] = djdev->device_index;
+               return hid_hw_raw_request(djrcv_dev->hdev, reportnum, buf,
+                               count, report_type, reqtype);
+       }
+
        if (buf[0] != REPORT_TYPE_LEDS)
                return -EINVAL;
 
@@ -687,6 +765,8 @@ static int logi_dj_ll_parse(struct hid_device *hid)
                        __func__, djdev->reports_supported);
        }
 
+       rdcat(rdesc, &rsize, hidpp_descriptor, sizeof(hidpp_descriptor));
+
        retval = hid_parse_report(hid, rdesc, rsize);
        kfree(rdesc);
 
@@ -714,8 +794,7 @@ static struct hid_ll_driver logi_dj_ll_driver = {
        .raw_request = logi_dj_ll_raw_request,
 };
 
-
-static int logi_dj_raw_event(struct hid_device *hdev,
+static int logi_dj_dj_event(struct hid_device *hdev,
                             struct hid_report *report, u8 *data,
                             int size)
 {
@@ -723,36 +802,24 @@ static int logi_dj_raw_event(struct hid_device *hdev,
        struct dj_report *dj_report = (struct dj_report *) data;
        unsigned long flags;
 
-       dbg_hid("%s, size:%d\n", __func__, size);
-
-       /* Here we receive all data coming from iface 2, there are 4 cases:
-        *
-        * 1) Data should continue its normal processing i.e. data does not
-        * come from the DJ collection, in which case we do nothing and
-        * return 0, so hid-core can continue normal processing (will forward
-        * to associated hidraw device)
+       /*
+        * Here we receive all data coming from iface 2, there are 3 cases:
         *
-        * 2) Data is from DJ collection, and is intended for this driver i. e.
-        * data contains arrival, departure, etc notifications, in which case
-        * we queue them for delayed processing by the work queue. We return 1
-        * to hid-core as no further processing is required from it.
+        * 1) Data is intended for this driver i. e. data contains arrival,
+        * departure, etc notifications, in which case we queue them for delayed
+        * processing by the work queue. We return 1 to hid-core as no further
+        * processing is required from it.
         *
-        * 3) Data is from DJ collection, and informs a connection change,
-        * if the change means rf link loss, then we must send a null report
-        * to the upper layer to discard potentially pressed keys that may be
-        * repeated forever by the input layer. Return 1 to hid-core as no
-        * further processing is required.
+        * 2) Data informs a connection change, if the change means rf link
+        * loss, then we must send a null report to the upper layer to discard
+        * potentially pressed keys that may be repeated forever by the input
+        * layer. Return 1 to hid-core as no further processing is required.
         *
-        * 4) Data is from DJ collection and is an actual input event from
-        * a paired DJ device in which case we forward it to the correct hid
-        * device (via hid_input_report() ) and return 1 so hid-core does not do
-        * anything else with it.
+        * 3) Data is an actual input event from a paired DJ device in which
+        * case we forward it to the correct hid device (via hid_input_report()
+        * ) and return 1 so hid-core does not anything else with it.
         */
 
-       /* case 1) */
-       if (data[0] != REPORT_ID_DJ_SHORT)
-               return false;
-
        if ((dj_report->device_index < DJ_DEVICE_INDEX_MIN) ||
            (dj_report->device_index > DJ_DEVICE_INDEX_MAX)) {
                /*
@@ -797,6 +864,71 @@ out:
        return true;
 }
 
+static int logi_dj_hidpp_event(struct hid_device *hdev,
+                            struct hid_report *report, u8 *data,
+                            int size)
+{
+       struct dj_receiver_dev *djrcv_dev = hid_get_drvdata(hdev);
+       struct dj_report *dj_report = (struct dj_report *) data;
+       unsigned long flags;
+       u8 device_index = dj_report->device_index;
+
+       if (device_index == HIDPP_RECEIVER_INDEX)
+               return false;
+
+       /*
+        * Data is from the HID++ collection, in this case, we forward the
+        * data to the corresponding child dj device and return 0 to hid-core
+        * so he data also goes to the hidraw device of the receiver. This
+        * allows a user space application to implement the full HID++ routing
+        * via the receiver.
+        */
+
+       if ((device_index < DJ_DEVICE_INDEX_MIN) ||
+           (device_index > DJ_DEVICE_INDEX_MAX)) {
+               /*
+                * Device index is wrong, bail out.
+                * This driver can ignore safely the receiver notifications,
+                * so ignore those reports too.
+                */
+               dev_err(&hdev->dev, "%s: invalid device index:%d\n",
+                               __func__, dj_report->device_index);
+               return false;
+       }
+
+       spin_lock_irqsave(&djrcv_dev->lock, flags);
+
+       if (!djrcv_dev->paired_dj_devices[device_index])
+               /* received an event for an unknown device, bail out */
+               goto out;
+
+       logi_dj_recv_forward_hidpp(djrcv_dev->paired_dj_devices[device_index],
+                                  data, size);
+
+out:
+       spin_unlock_irqrestore(&djrcv_dev->lock, flags);
+
+       return false;
+}
+
+static int logi_dj_raw_event(struct hid_device *hdev,
+                            struct hid_report *report, u8 *data,
+                            int size)
+{
+       dbg_hid("%s, size:%d\n", __func__, size);
+
+       switch (data[0]) {
+       case REPORT_ID_DJ_SHORT:
+               return logi_dj_dj_event(hdev, report, data, size);
+       case REPORT_ID_HIDPP_SHORT:
+               /* intentional fallthrough */
+       case REPORT_ID_HIDPP_LONG:
+               return logi_dj_hidpp_event(hdev, report, data, size);
+       }
+
+       return false;
+}
+
 static int logi_dj_probe(struct hid_device *hdev,
                         const struct hid_device_id *id)
 {