From a1d97ccbb4d05c049dffafc23fe62f0dd1a06d83 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Sat, 20 Apr 2019 13:21:52 +0200 Subject: [PATCH] HID: logitech-dj: support sharing struct dj_receiver_dev between USB-interfaces dj/HID++ receivers are really a single logical entity, but for BIOS/Windows compatibility they have multiple USB interfaces. For the upcoming non-unifying receiver support, we need to listen for events from / bind to all USB-interfaces of the receiver. This commit add support to the logitech-dj code for creating a single dj_receiver_dev struct for all interfaces belonging to a single USB-device / receiver, in preparation for adding non-unifying receiver support. Signed-off-by: Hans de Goede Signed-off-by: Benjamin Tissoires --- drivers/hid/hid-logitech-dj.c | 176 +++++++++++++++++++++++++++++++++++------- 1 file changed, 149 insertions(+), 27 deletions(-) diff --git a/drivers/hid/hid-logitech-dj.c b/drivers/hid/hid-logitech-dj.c index 6244fd4..a3ad100 100644 --- a/drivers/hid/hid-logitech-dj.c +++ b/drivers/hid/hid-logitech-dj.c @@ -119,11 +119,16 @@ struct hidpp_event { } __packed; struct dj_receiver_dev { + struct hid_device *mouse; + struct hid_device *keyboard; struct hid_device *hidpp; struct dj_device *paired_dj_devices[DJ_MAX_PAIRED_DEVICES + DJ_DEVICE_INDEX_MIN]; + struct list_head list; + struct kref kref; struct work_struct work; struct kfifo notif_fifo; + bool ready; spinlock_t lock; }; @@ -363,6 +368,110 @@ static const u8 hid_reportid_size_map[NUMBER_OF_HID_REPORTS] = { static struct hid_ll_driver logi_dj_ll_driver; static int logi_dj_recv_query_paired_devices(struct dj_receiver_dev *djrcv_dev); +static void delayedwork_callback(struct work_struct *work); + +static LIST_HEAD(dj_hdev_list); +static DEFINE_MUTEX(dj_hdev_list_lock); + +/* + * dj/HID++ receivers are really a single logical entity, but for BIOS/Windows + * compatibility they have multiple USB interfaces. On HID++ receivers we need + * to listen for input reports on both interfaces. The functions below are used + * to create a single struct dj_receiver_dev for all interfaces belonging to + * a single USB-device / receiver. + */ +static struct dj_receiver_dev *dj_find_receiver_dev(struct hid_device *hdev) +{ + struct dj_receiver_dev *djrcv_dev; + + /* Try to find an already-probed interface from the same device */ + list_for_each_entry(djrcv_dev, &dj_hdev_list, list) { + if (djrcv_dev->mouse && + hid_compare_device_paths(hdev, djrcv_dev->mouse, '/')) { + kref_get(&djrcv_dev->kref); + return djrcv_dev; + } + if (djrcv_dev->keyboard && + hid_compare_device_paths(hdev, djrcv_dev->keyboard, '/')) { + kref_get(&djrcv_dev->kref); + return djrcv_dev; + } + if (djrcv_dev->hidpp && + hid_compare_device_paths(hdev, djrcv_dev->hidpp, '/')) { + kref_get(&djrcv_dev->kref); + return djrcv_dev; + } + } + + return NULL; +} + +static void dj_release_receiver_dev(struct kref *kref) +{ + struct dj_receiver_dev *djrcv_dev = container_of(kref, struct dj_receiver_dev, kref); + + list_del(&djrcv_dev->list); + kfifo_free(&djrcv_dev->notif_fifo); + kfree(djrcv_dev); +} + +static void dj_put_receiver_dev(struct hid_device *hdev) +{ + struct dj_receiver_dev *djrcv_dev = hid_get_drvdata(hdev); + + mutex_lock(&dj_hdev_list_lock); + + if (djrcv_dev->mouse == hdev) + djrcv_dev->mouse = NULL; + if (djrcv_dev->keyboard == hdev) + djrcv_dev->keyboard = NULL; + if (djrcv_dev->hidpp == hdev) + djrcv_dev->hidpp = NULL; + + kref_put(&djrcv_dev->kref, dj_release_receiver_dev); + + mutex_unlock(&dj_hdev_list_lock); +} + +static struct dj_receiver_dev *dj_get_receiver_dev(struct hid_device *hdev, + unsigned int application, + bool is_hidpp) +{ + struct dj_receiver_dev *djrcv_dev; + + mutex_lock(&dj_hdev_list_lock); + + djrcv_dev = dj_find_receiver_dev(hdev); + if (!djrcv_dev) { + djrcv_dev = kzalloc(sizeof(*djrcv_dev), GFP_KERNEL); + if (!djrcv_dev) + goto out; + + INIT_WORK(&djrcv_dev->work, delayedwork_callback); + spin_lock_init(&djrcv_dev->lock); + if (kfifo_alloc(&djrcv_dev->notif_fifo, + DJ_MAX_NUMBER_NOTIFS * sizeof(struct dj_workitem), + GFP_KERNEL)) { + kfree(djrcv_dev); + djrcv_dev = NULL; + goto out; + } + kref_init(&djrcv_dev->kref); + list_add_tail(&djrcv_dev->list, &dj_hdev_list); + } + + if (application == HID_GD_KEYBOARD) + djrcv_dev->keyboard = hdev; + if (application == HID_GD_MOUSE) + djrcv_dev->mouse = hdev; + if (is_hidpp) + djrcv_dev->hidpp = hdev; + + hid_set_drvdata(hdev, djrcv_dev); +out: + mutex_unlock(&dj_hdev_list_lock); + return djrcv_dev; +} static void logi_dj_recv_destroy_djhid_device(struct dj_receiver_dev *djrcv_dev, struct dj_workitem *workitem) @@ -480,6 +589,17 @@ static void delayedwork_callback(struct work_struct *work) spin_lock_irqsave(&djrcv_dev->lock, flags); + /* + * Since we attach to multiple interfaces, we may get scheduled before + * we are bound to the HID++ interface, catch this. + */ + if (!djrcv_dev->ready) { + pr_warn("%s: delayedwork queued before hidpp interface was enumerated\n", + __func__); + spin_unlock_irqrestore(&djrcv_dev->lock, flags); + return; + } + count = kfifo_out(&djrcv_dev->notif_fifo, &workitem, sizeof(workitem)); if (count != sizeof(workitem)) { @@ -1043,6 +1163,7 @@ static int logi_dj_probe(struct hid_device *hdev, struct hid_report *rep; struct dj_receiver_dev *djrcv_dev; bool has_hidpp = false; + unsigned long flags; int retval; /* @@ -1076,27 +1197,15 @@ static int logi_dj_probe(struct hid_device *hdev, if (!has_hidpp) return -ENODEV; - /* Treat DJ/HID++ interface */ - - djrcv_dev = kzalloc(sizeof(struct dj_receiver_dev), GFP_KERNEL); + /* get the current application attached to the node */ + rep = list_first_entry(&rep_enum->report_list, struct hid_report, list); + djrcv_dev = dj_get_receiver_dev(hdev, + rep->application, has_hidpp); if (!djrcv_dev) { dev_err(&hdev->dev, "%s:failed allocating dj_receiver_dev\n", __func__); return -ENOMEM; } - djrcv_dev->hidpp = hdev; - INIT_WORK(&djrcv_dev->work, delayedwork_callback); - spin_lock_init(&djrcv_dev->lock); - if (kfifo_alloc(&djrcv_dev->notif_fifo, - DJ_MAX_NUMBER_NOTIFS * sizeof(struct dj_workitem), - GFP_KERNEL)) { - dev_err(&hdev->dev, - "%s:failed allocating notif_fifo\n", __func__); - kfree(djrcv_dev); - return -ENOMEM; - } - hid_set_drvdata(hdev, djrcv_dev); - /* Starts the usb device and connects to upper interfaces hiddev and * hidraw */ @@ -1126,6 +1235,9 @@ static int logi_dj_probe(struct hid_device *hdev, /* Allow incoming packets to arrive: */ hid_device_io_start(hdev); + spin_lock_irqsave(&djrcv_dev->lock, flags); + djrcv_dev->ready = true; + spin_unlock_irqrestore(&djrcv_dev->lock, flags); retval = logi_dj_recv_query_paired_devices(djrcv_dev); if (retval < 0) { dev_err(&hdev->dev, "%s:logi_dj_recv_query_paired_devices " @@ -1143,10 +1255,8 @@ switch_to_dj_mode_fail: hid_hw_stop(hdev); hid_hw_start_fail: - kfifo_free(&djrcv_dev->notif_fifo); - kfree(djrcv_dev); + dj_put_receiver_dev(hdev); return retval; - } #ifdef CONFIG_PM @@ -1170,31 +1280,43 @@ static void logi_dj_remove(struct hid_device *hdev) { struct dj_receiver_dev *djrcv_dev = hid_get_drvdata(hdev); struct dj_device *dj_dev; + unsigned long flags; int i; dbg_hid("%s\n", __func__); + /* + * This ensures that if the work gets requeued from another + * interface of the same receiver it will be a no-op. + */ + spin_lock_irqsave(&djrcv_dev->lock, flags); + djrcv_dev->ready = false; + spin_unlock_irqrestore(&djrcv_dev->lock, flags); + cancel_work_sync(&djrcv_dev->work); hid_hw_close(hdev); hid_hw_stop(hdev); - /* I suppose that at this point the only context that can access - * the djrecv_data is this thread as the work item is guaranteed to - * have finished and no more raw_event callbacks should arrive after - * the remove callback was triggered so no locks are put around the - * code below */ + /* + * For proper operation we need access to all interfaces, so we destroy + * the paired devices when we're unbound from any interface. + * + * Note we may still be bound to other interfaces, sharing the same + * djrcv_dev, so we need locking here. + */ for (i = 0; i < (DJ_MAX_PAIRED_DEVICES + DJ_DEVICE_INDEX_MIN); i++) { + spin_lock_irqsave(&djrcv_dev->lock, flags); dj_dev = djrcv_dev->paired_dj_devices[i]; + djrcv_dev->paired_dj_devices[i] = NULL; + spin_unlock_irqrestore(&djrcv_dev->lock, flags); if (dj_dev != NULL) { hid_destroy_device(dj_dev->hdev); kfree(dj_dev); - djrcv_dev->paired_dj_devices[i] = NULL; } } - kfifo_free(&djrcv_dev->notif_fifo); - kfree(djrcv_dev); + dj_put_receiver_dev(hdev); } static const struct hid_device_id logi_dj_receivers[] = { -- 2.7.4