+/*
+ * HIDPP protocol for Logitech Unifying receivers
+ *
+ * Copyright (c) 2011 Logitech (c)
+ */
+
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Should you need to contact me, the author, you can do so by e-mail send
+ * your message to Benjamin Tissoires <benjamin.tissoires at gmail com>
+ *
+ */
+
+
+#include <linux/device.h>
+#include <linux/hid.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include "hid-logitech-hidpp.h"
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
+MODULE_AUTHOR("Nestor Lopez Casado <nlopezcasad@logitech.com>");
+
+#define MAX_INIT_RETRY 5
+
+enum delayed_work_type {
+ HIDPP_INIT = 0
+};
+
+static void hidpp_print_raw_event(const char *header, u8 *data, int size)
+{
+ int i;
+ unsigned char log[96];
+ unsigned char tmpstr[60];
+
+ snprintf(log, sizeof(tmpstr), "%s (size=%d)", header, size);
+
+ for (i = 0; i < size; i++) {
+ snprintf(tmpstr, sizeof(tmpstr), " %02x", data[i]);
+ strlcat(log, tmpstr, sizeof(log));
+ }
+
+ dbg_hid("%s\n", log);
+}
+
+static int __hidpp_send_report(struct hid_device *hdev,
+ struct hidpp_report *hidpp_rept)
+{
+ int sent_bytes;
+
+ if (!hdev->hid_output_raw_report) {
+ dev_err(&hdev->dev, "%s:"
+ "hid_output_raw_report is null\n", __func__);
+ return -ENODEV;
+ }
+
+ hidpp_print_raw_event("sending ", (u8 *)hidpp_rept,
+ HIDPP_REPORT_LONG_LENGTH);
+ sent_bytes = hdev->hid_output_raw_report(hdev, (u8 *) hidpp_rept,
+ sizeof(struct hidpp_report),
+ HID_OUTPUT_REPORT);
+
+ return (sent_bytes < 0) ? sent_bytes : 0;
+}
+
+static int hidpp_send_message_sync(struct hidpp_device *hidpp_dev,
+ struct hidpp_report *message,
+ struct hidpp_report *response)
+{
+ int ret;
+
+ mutex_lock(&hidpp_dev->send_mutex);
+
+ hidpp_dev->send_receive_buf = response;
+ hidpp_dev->answer_available = false;
+
+ /* So that we can later validate the answer when it arrives
+ * in hidpp_raw_event */
+ *response = *message;
+
+ ret = __hidpp_send_report(hidpp_dev->hid_dev, message);
+
+ if (ret) {
+ dbg_hid("__hidpp_send_report returned err: %d\n", ret);
+ memset(response, 0, sizeof(struct hidpp_report));
+ goto exit;
+ }
+
+ if (!wait_event_timeout(hidpp_dev->wait, hidpp_dev->answer_available, 10*HZ)) {
+ dbg_hid("%s:timeout waiting for response\n", __func__);
+ memset(response, 0, sizeof(struct hidpp_report));
+ ret = -1;
+ }
+
+ if (response->report_id == REPORT_ID_HIDPP_SHORT &&
+ response->fap.feature_index == HIDPP_ERROR) {
+ ret = response->fap.params[0];
+ dbg_hid("__hidpp_send_report got hidpp error %d\n", ret);
+ goto exit;
+ }
+
+exit:
+ mutex_unlock(&hidpp_dev->send_mutex);
+ return ret;
+
+}
+
+int hidpp_send_fap_command_sync(struct hidpp_device *hidpp_dev,
+ u8 feat_index, u8 funcindex_clientid, u8 *params, int param_count,
+ struct hidpp_report *response)
+{
+ struct hidpp_report message;
+
+ if (param_count > sizeof(message.rap.params))
+ return -EINVAL;
+
+ memset(&message, 0, sizeof(message));
+ message.report_id = REPORT_ID_HIDPP_LONG;
+ message.fap.feature_index = feat_index;
+ message.fap.funcindex_clientid = funcindex_clientid;
+ memcpy(&message.fap.params, params, param_count);
+
+ return hidpp_send_message_sync(hidpp_dev, &message, response);
+}
+EXPORT_SYMBOL_GPL(hidpp_send_fap_command_sync);
+
+int hidpp_send_rap_command_sync(struct hidpp_device *hidpp_dev,
+ u8 report_id, u8 sub_id, u8 reg_address, u8 *params,
+ int param_count,
+ struct hidpp_report *response)
+{
+ struct hidpp_report message;
+
+ if ((report_id != REPORT_ID_HIDPP_SHORT) &&
+ (report_id != REPORT_ID_HIDPP_LONG))
+ return -EINVAL;
+
+ if (param_count > sizeof(message.rap.params))
+ return -EINVAL;
+
+ memset(&message, 0, sizeof(message));
+ message.report_id = report_id;
+ message.rap.sub_id = sub_id;
+ message.rap.reg_address = reg_address;
+ memcpy(&message.rap.params, params, param_count);
+
+ return hidpp_send_message_sync(hidpp_dev, &message, response);
+}
+EXPORT_SYMBOL_GPL(hidpp_send_rap_command_sync);
+
+
+static void schedule_delayed_hidpp_init(struct hidpp_device *hidpp_dev)
+{
+ enum delayed_work_type work_type = HIDPP_INIT;
+
+ kfifo_in(&hidpp_dev->delayed_work_fifo, &work_type,
+ sizeof(enum delayed_work_type));
+
+ if (schedule_work(&hidpp_dev->work) == 0) {
+ dbg_hid("%s: did not schedule the work item,"
+ " was already queued\n",
+ __func__);
+ }
+}
+
+void hidpp_delayed_init(struct hidpp_device *hidpp_device)
+{
+ struct hid_device *hdev = hidpp_device->hid_dev;
+ int ret = 0;
+
+ dbg_hid("%s: hdev:%p\n", __func__, hdev);
+
+ if (hidpp_device->initialized)
+ return;
+
+ if (down_trylock(&hidpp_device->hid_dev->driver_lock)) {
+ if (hidpp_device->init_retry < MAX_INIT_RETRY) {
+ dbg_hid("%s: we need to reschedule the work item."
+ "Semaphore still held on device\n", __func__);
+ schedule_delayed_hidpp_init(hidpp_device);
+ hidpp_device->init_retry++;
+ } else {
+ dbg_hid("%s: giving up initialization now.", __func__);
+ hidpp_device->init_retry = 0;
+ }
+ return;
+ }
+ up(&hidpp_device->hid_dev->driver_lock);
+
+ if (hidpp_device->device_init)
+ ret = hidpp_device->device_init(hidpp_device);
+
+ if (!ret)
+ hidpp_device->initialized = true;
+}
+EXPORT_SYMBOL_GPL(hidpp_delayed_init);
+
+static void delayed_work_cb(struct work_struct *work)
+{
+ struct hidpp_device *hidpp_device =
+ container_of(work, struct hidpp_device, work);
+ unsigned long flags;
+ int count;
+ enum delayed_work_type work_type;
+
+ dbg_hid("%s\n", __func__);
+
+ spin_lock_irqsave(&hidpp_device->lock, flags);
+
+ count = kfifo_out(&hidpp_device->delayed_work_fifo, &work_type,
+ sizeof(enum delayed_work_type));
+
+ if (count != sizeof(enum delayed_work_type)) {
+ dev_err(&hidpp_device->hid_dev->dev, "%s: workitem triggered without "
+ "notifications available\n", __func__);
+ spin_unlock_irqrestore(&hidpp_device->lock, flags);
+ return;
+ }
+
+ if (!kfifo_is_empty(&hidpp_device->delayed_work_fifo)) {
+ if (schedule_work(&hidpp_device->work) == 0) {
+ dbg_hid("%s: did not schedule the work item, was "
+ "already queued\n", __func__);
+ }
+ }
+
+ spin_unlock_irqrestore(&hidpp_device->lock, flags);
+
+ switch (work_type) {
+ case HIDPP_INIT:
+ hidpp_delayed_init(hidpp_device);
+ break;
+ default:
+ dbg_hid("%s: unexpected report type\n", __func__);
+ }
+}
+
+int hidpp_init(struct hidpp_device *hidpp_dev, struct hid_device *hid_dev)
+{
+ if (hidpp_dev->initialized)
+ return 0;
+
+ hidpp_dev->init_retry = 0;
+ hidpp_dev->hid_dev = hid_dev;
+ hidpp_dev->initialized = 1;
+
+ INIT_WORK(&hidpp_dev->work, delayed_work_cb);
+ mutex_init(&hidpp_dev->send_mutex);
+ init_waitqueue_head(&hidpp_dev->wait);
+
+ spin_lock_init(&hidpp_dev->lock);
+ if (kfifo_alloc(&hidpp_dev->delayed_work_fifo,
+ 4 * sizeof(struct hidpp_report),
+ GFP_KERNEL)) {
+ dev_err(&hidpp_dev->hid_dev->dev,
+ "%s:failed allocating delayed_work_fifo\n", __func__);
+ mutex_destroy(&hidpp_dev->send_mutex);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(hidpp_init);
+
+void hidpp_connect_change(struct hidpp_device *hidpp_dev, bool connected)
+{
+ if ((!hidpp_dev->initialized) && (connected))
+ hidpp_delayed_init(hidpp_dev);
+
+ if (hidpp_dev->connect_change)
+ hidpp_dev->connect_change(hidpp_dev, connected);
+}
+EXPORT_SYMBOL_GPL(hidpp_connect_change);
+
+void hidpp_remove(struct hidpp_device *hidpp_dev)
+{
+ dbg_hid("%s\n", __func__);
+ cancel_work_sync(&hidpp_dev->work);
+ mutex_destroy(&hidpp_dev->send_mutex);
+ kfifo_free(&hidpp_dev->delayed_work_fifo);
+ hidpp_dev->initialized = false;
+ hidpp_dev->hid_dev = NULL;
+}
+EXPORT_SYMBOL_GPL(hidpp_remove);
+
+int hidpp_raw_event(struct hid_device *hdev, struct hid_report *hid_report,
+ u8 *data, int size)
+{
+ struct hidpp_device *hidpp_dev = hid_get_drvdata(hdev);
+ struct hidpp_report *report = (struct hidpp_report *)data;
+ struct hidpp_report *question = hidpp_dev->send_receive_buf;
+ struct hidpp_report *answer = hidpp_dev->send_receive_buf;
+
+ dbg_hid("%s\n", __func__);
+
+ hidpp_print_raw_event("hidpp_raw_event", data, size);
+
+ if ((report->report_id != REPORT_ID_HIDPP_LONG) &&
+ (report->report_id != REPORT_ID_HIDPP_SHORT)) {
+ dbg_hid("hid-logitech-hidpp.c:%s: ignore report_id:%d\n",
+ __func__, report->report_id);
+ return 0;
+ }
+
+ /* If the mutex is locked then we have a pending answer from a
+ * previoulsly sent command
+ */
+ if (unlikely(mutex_is_locked(&hidpp_dev->send_mutex))) {
+ /* Check for a correct hidpp20 answer */
+ bool correct_answer =
+ report->fap.feature_index == question->fap.feature_index &&
+ report->fap.funcindex_clientid == question->fap.funcindex_clientid;
+ dbg_hid("%s mutex is locked, waiting for reply\n", __func__);
+
+ /* Check for a "correct" hidpp10 error message, this means the
+ * device is hidpp10 and does not support the command sent */
+ correct_answer = correct_answer ||
+ (report->fap.feature_index == HIDPP_ERROR &&
+ report->fap.funcindex_clientid == question->fap.feature_index &&
+ report->fap.params[0] == question->fap.funcindex_clientid);
+
+ if (correct_answer) {
+ hidpp_print_raw_event("answer", data, size);
+ *answer = *report;
+ hidpp_dev->answer_available = true;
+ wake_up(&hidpp_dev->wait);
+ /* This was an answer to a command that this driver sent
+ * we return 1 to hid-core to avoid forwarding the command
+ * upstream as it has been treated by the driver */
+
+ return 1;
+ }
+ }
+
+ if (hidpp_dev->raw_event != NULL)
+ return hidpp_dev->raw_event(hidpp_dev, report);
+
+ hidpp_print_raw_event("event not treated", data, size);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(hidpp_raw_event);