--- /dev/null
+/*
+ * cec-api.c - HDMI Consumer Electronics Control framework - API
+ *
+ * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
+ *
+ * This program is free software; you may redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/kmod.h>
+#include <linux/ktime.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include <linux/version.h>
+
+#include "cec-priv.h"
+
+static inline struct cec_devnode *cec_devnode_data(struct file *filp)
+{
+ struct cec_fh *fh = filp->private_data;
+
+ return &fh->adap->devnode;
+}
+
+/* CEC file operations */
+
+static unsigned int cec_poll(struct file *filp,
+ struct poll_table_struct *poll)
+{
+ struct cec_devnode *devnode = cec_devnode_data(filp);
+ struct cec_fh *fh = filp->private_data;
+ struct cec_adapter *adap = fh->adap;
+ unsigned int res = 0;
+
+ if (!devnode->registered)
+ return POLLERR | POLLHUP;
+ mutex_lock(&adap->lock);
+ if (adap->is_configured)
+ res |= POLLOUT | POLLWRNORM;
+ if (fh->queued_msgs)
+ res |= POLLIN | POLLRDNORM;
+ if (fh->pending_events)
+ res |= POLLPRI;
+ poll_wait(filp, &fh->wait, poll);
+ mutex_unlock(&adap->lock);
+ return res;
+}
+
+static bool cec_is_busy(const struct cec_adapter *adap,
+ const struct cec_fh *fh)
+{
+ bool valid_initiator = adap->cec_initiator && adap->cec_initiator == fh;
+ bool valid_follower = adap->cec_follower && adap->cec_follower == fh;
+
+ /*
+ * Exclusive initiators and followers can always access the CEC adapter
+ */
+ if (valid_initiator || valid_follower)
+ return false;
+ /*
+ * All others can only access the CEC adapter if there is no
+ * exclusive initiator and they are in INITIATOR mode.
+ */
+ return adap->cec_initiator ||
+ fh->mode_initiator == CEC_MODE_NO_INITIATOR;
+}
+
+static long cec_adap_g_caps(struct cec_adapter *adap,
+ struct cec_caps __user *parg)
+{
+ struct cec_caps caps = {};
+
+ strlcpy(caps.driver, adap->devnode.parent->driver->name,
+ sizeof(caps.driver));
+ strlcpy(caps.name, adap->name, sizeof(caps.name));
+ caps.available_log_addrs = adap->available_log_addrs;
+ caps.capabilities = adap->capabilities;
+ caps.version = LINUX_VERSION_CODE;
+ if (copy_to_user(parg, &caps, sizeof(caps)))
+ return -EFAULT;
+ return 0;
+}
+
+static long cec_adap_g_phys_addr(struct cec_adapter *adap,
+ __u16 __user *parg)
+{
+ u16 phys_addr;
+
+ mutex_lock(&adap->lock);
+ phys_addr = adap->phys_addr;
+ mutex_unlock(&adap->lock);
+ if (copy_to_user(parg, &phys_addr, sizeof(phys_addr)))
+ return -EFAULT;
+ return 0;
+}
+
+static long cec_adap_s_phys_addr(struct cec_adapter *adap, struct cec_fh *fh,
+ bool block, __u16 __user *parg)
+{
+ u16 phys_addr;
+ long err;
+
+ if (!(adap->capabilities & CEC_CAP_PHYS_ADDR))
+ return -ENOTTY;
+ if (copy_from_user(&phys_addr, parg, sizeof(phys_addr)))
+ return -EFAULT;
+
+ err = cec_phys_addr_validate(phys_addr, NULL, NULL);
+ if (err)
+ return err;
+ mutex_lock(&adap->lock);
+ if (cec_is_busy(adap, fh))
+ err = -EBUSY;
+ else
+ __cec_s_phys_addr(adap, phys_addr, block);
+ mutex_unlock(&adap->lock);
+ return err;
+}
+
+static long cec_adap_g_log_addrs(struct cec_adapter *adap,
+ struct cec_log_addrs __user *parg)
+{
+ struct cec_log_addrs log_addrs;
+
+ mutex_lock(&adap->lock);
+ log_addrs = adap->log_addrs;
+ if (!adap->is_configured)
+ memset(log_addrs.log_addr, CEC_LOG_ADDR_INVALID,
+ sizeof(log_addrs.log_addr));
+ mutex_unlock(&adap->lock);
+
+ if (copy_to_user(parg, &log_addrs, sizeof(log_addrs)))
+ return -EFAULT;
+ return 0;
+}
+
+static long cec_adap_s_log_addrs(struct cec_adapter *adap, struct cec_fh *fh,
+ bool block, struct cec_log_addrs __user *parg)
+{
+ struct cec_log_addrs log_addrs;
+ long err = -EBUSY;
+
+ if (!(adap->capabilities & CEC_CAP_LOG_ADDRS))
+ return -ENOTTY;
+ if (copy_from_user(&log_addrs, parg, sizeof(log_addrs)))
+ return -EFAULT;
+ log_addrs.flags = 0;
+ mutex_lock(&adap->lock);
+ if (!adap->is_configuring &&
+ (!log_addrs.num_log_addrs || !adap->is_configured) &&
+ !cec_is_busy(adap, fh)) {
+ err = __cec_s_log_addrs(adap, &log_addrs, block);
+ if (!err)
+ log_addrs = adap->log_addrs;
+ }
+ mutex_unlock(&adap->lock);
+ if (err)
+ return err;
+ if (copy_to_user(parg, &log_addrs, sizeof(log_addrs)))
+ return -EFAULT;
+ return 0;
+}
+
+static long cec_transmit(struct cec_adapter *adap, struct cec_fh *fh,
+ bool block, struct cec_msg __user *parg)
+{
+ struct cec_msg msg = {};
+ long err = 0;
+
+ if (!(adap->capabilities & CEC_CAP_TRANSMIT))
+ return -ENOTTY;
+ if (copy_from_user(&msg, parg, sizeof(msg)))
+ return -EFAULT;
+ mutex_lock(&adap->lock);
+ if (!adap->is_configured) {
+ err = -ENONET;
+ } else if (cec_is_busy(adap, fh)) {
+ err = -EBUSY;
+ } else {
+ if (!block || !msg.reply)
+ fh = NULL;
+ err = cec_transmit_msg_fh(adap, &msg, fh, block);
+ }
+ mutex_unlock(&adap->lock);
+ if (err)
+ return err;
+ if (copy_to_user(parg, &msg, sizeof(msg)))
+ return -EFAULT;
+ return 0;
+}
+
+/* Called by CEC_RECEIVE: wait for a message to arrive */
+static int cec_receive_msg(struct cec_fh *fh, struct cec_msg *msg, bool block)
+{
+ int res;
+
+ do {
+ mutex_lock(&fh->lock);
+ /* Are there received messages queued up? */
+ if (fh->queued_msgs) {
+ /* Yes, return the first one */
+ struct cec_msg_entry *entry =
+ list_first_entry(&fh->msgs,
+ struct cec_msg_entry, list);
+
+ list_del(&entry->list);
+ *msg = entry->msg;
+ kfree(entry);
+ fh->queued_msgs--;
+ mutex_unlock(&fh->lock);
+ return 0;
+ }
+
+ /* No, return EAGAIN in non-blocking mode or wait */
+ mutex_unlock(&fh->lock);
+
+ /* Return when in non-blocking mode */
+ if (!block)
+ return -EAGAIN;
+
+ if (msg->timeout) {
+ /* The user specified a timeout */
+ res = wait_event_interruptible_timeout(fh->wait,
+ fh->queued_msgs,
+ msecs_to_jiffies(msg->timeout));
+ if (res == 0)
+ res = -ETIMEDOUT;
+ else if (res > 0)
+ res = 0;
+ } else {
+ /* Wait indefinitely */
+ res = wait_event_interruptible(fh->wait,
+ fh->queued_msgs);
+ }
+ /* Exit on error, otherwise loop to get the new message */
+ } while (!res);
+ return res;
+}
+
+static long cec_receive(struct cec_adapter *adap, struct cec_fh *fh,
+ bool block, struct cec_msg __user *parg)
+{
+ struct cec_msg msg = {};
+ long err = 0;
+
+ if (copy_from_user(&msg, parg, sizeof(msg)))
+ return -EFAULT;
+ mutex_lock(&adap->lock);
+ if (!adap->is_configured)
+ err = -ENONET;
+ mutex_unlock(&adap->lock);
+ if (err)
+ return err;
+
+ err = cec_receive_msg(fh, &msg, block);
+ if (err)
+ return err;
+ if (copy_to_user(parg, &msg, sizeof(msg)))
+ return -EFAULT;
+ return 0;
+}
+
+static long cec_dqevent(struct cec_adapter *adap, struct cec_fh *fh,
+ bool block, struct cec_event __user *parg)
+{
+ struct cec_event *ev = NULL;
+ u64 ts = ~0ULL;
+ unsigned int i;
+ long err = 0;
+
+ mutex_lock(&fh->lock);
+ while (!fh->pending_events && block) {
+ mutex_unlock(&fh->lock);
+ err = wait_event_interruptible(fh->wait, fh->pending_events);
+ if (err)
+ return err;
+ mutex_lock(&fh->lock);
+ }
+
+ /* Find the oldest event */
+ for (i = 0; i < CEC_NUM_EVENTS; i++) {
+ if (fh->pending_events & (1 << (i + 1)) &&
+ fh->events[i].ts <= ts) {
+ ev = &fh->events[i];
+ ts = ev->ts;
+ }
+ }
+ if (!ev) {
+ err = -EAGAIN;
+ goto unlock;
+ }
+
+ if (copy_to_user(parg, ev, sizeof(*ev))) {
+ err = -EFAULT;
+ goto unlock;
+ }
+
+ fh->pending_events &= ~(1 << ev->event);
+
+unlock:
+ mutex_unlock(&fh->lock);
+ return err;
+}
+
+static long cec_g_mode(struct cec_adapter *adap, struct cec_fh *fh,
+ u32 __user *parg)
+{
+ u32 mode = fh->mode_initiator | fh->mode_follower;
+
+ if (copy_to_user(parg, &mode, sizeof(mode)))
+ return -EFAULT;
+ return 0;
+}
+
+static long cec_s_mode(struct cec_adapter *adap, struct cec_fh *fh,
+ u32 __user *parg)
+{
+ u32 mode;
+ u8 mode_initiator;
+ u8 mode_follower;
+ long err = 0;
+
+ if (copy_from_user(&mode, parg, sizeof(mode)))
+ return -EFAULT;
+ if (mode & ~(CEC_MODE_INITIATOR_MSK | CEC_MODE_FOLLOWER_MSK))
+ return -EINVAL;
+
+ mode_initiator = mode & CEC_MODE_INITIATOR_MSK;
+ mode_follower = mode & CEC_MODE_FOLLOWER_MSK;
+
+ if (mode_initiator > CEC_MODE_EXCL_INITIATOR ||
+ mode_follower > CEC_MODE_MONITOR_ALL)
+ return -EINVAL;
+
+ if (mode_follower == CEC_MODE_MONITOR_ALL &&
+ !(adap->capabilities & CEC_CAP_MONITOR_ALL))
+ return -EINVAL;
+
+ /* Follower modes should always be able to send CEC messages */
+ if ((mode_initiator == CEC_MODE_NO_INITIATOR ||
+ !(adap->capabilities & CEC_CAP_TRANSMIT)) &&
+ mode_follower >= CEC_MODE_FOLLOWER &&
+ mode_follower <= CEC_MODE_EXCL_FOLLOWER_PASSTHRU)
+ return -EINVAL;
+
+ /* Monitor modes require CEC_MODE_NO_INITIATOR */
+ if (mode_initiator && mode_follower >= CEC_MODE_MONITOR)
+ return -EINVAL;
+
+ /* Monitor modes require CAP_NET_ADMIN */
+ if (mode_follower >= CEC_MODE_MONITOR && !capable(CAP_NET_ADMIN))
+ return -EPERM;
+
+ mutex_lock(&adap->lock);
+ /*
+ * You can't become exclusive follower if someone else already
+ * has that job.
+ */
+ if ((mode_follower == CEC_MODE_EXCL_FOLLOWER ||
+ mode_follower == CEC_MODE_EXCL_FOLLOWER_PASSTHRU) &&
+ adap->cec_follower && adap->cec_follower != fh)
+ err = -EBUSY;
+ /*
+ * You can't become exclusive initiator if someone else already
+ * has that job.
+ */
+ if (mode_initiator == CEC_MODE_EXCL_INITIATOR &&
+ adap->cec_initiator && adap->cec_initiator != fh)
+ err = -EBUSY;
+
+ if (!err) {
+ bool old_mon_all = fh->mode_follower == CEC_MODE_MONITOR_ALL;
+ bool new_mon_all = mode_follower == CEC_MODE_MONITOR_ALL;
+
+ if (old_mon_all != new_mon_all) {
+ if (new_mon_all)
+ err = cec_monitor_all_cnt_inc(adap);
+ else
+ cec_monitor_all_cnt_dec(adap);
+ }
+ }
+
+ if (err) {
+ mutex_unlock(&adap->lock);
+ return err;
+ }
+
+ if (fh->mode_follower == CEC_MODE_FOLLOWER)
+ adap->follower_cnt--;
+ if (mode_follower == CEC_MODE_FOLLOWER)
+ adap->follower_cnt++;
+ if (mode_follower == CEC_MODE_EXCL_FOLLOWER ||
+ mode_follower == CEC_MODE_EXCL_FOLLOWER_PASSTHRU) {
+ adap->passthrough =
+ mode_follower == CEC_MODE_EXCL_FOLLOWER_PASSTHRU;
+ adap->cec_follower = fh;
+ } else if (adap->cec_follower == fh) {
+ adap->passthrough = false;
+ adap->cec_follower = NULL;
+ }
+ if (mode_initiator == CEC_MODE_EXCL_INITIATOR)
+ adap->cec_initiator = fh;
+ else if (adap->cec_initiator == fh)
+ adap->cec_initiator = NULL;
+ fh->mode_initiator = mode_initiator;
+ fh->mode_follower = mode_follower;
+ mutex_unlock(&adap->lock);
+ return 0;
+}
+
+static long cec_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+ struct cec_devnode *devnode = cec_devnode_data(filp);
+ struct cec_fh *fh = filp->private_data;
+ struct cec_adapter *adap = fh->adap;
+ bool block = !(filp->f_flags & O_NONBLOCK);
+ void __user *parg = (void __user *)arg;
+
+ if (!devnode->registered)
+ return -EIO;
+
+ switch (cmd) {
+ case CEC_ADAP_G_CAPS:
+ return cec_adap_g_caps(adap, parg);
+
+ case CEC_ADAP_G_PHYS_ADDR:
+ return cec_adap_g_phys_addr(adap, parg);
+
+ case CEC_ADAP_S_PHYS_ADDR:
+ return cec_adap_s_phys_addr(adap, fh, block, parg);
+
+ case CEC_ADAP_G_LOG_ADDRS:
+ return cec_adap_g_log_addrs(adap, parg);
+
+ case CEC_ADAP_S_LOG_ADDRS:
+ return cec_adap_s_log_addrs(adap, fh, block, parg);
+
+ case CEC_TRANSMIT:
+ return cec_transmit(adap, fh, block, parg);
+
+ case CEC_RECEIVE:
+ return cec_receive(adap, fh, block, parg);
+
+ case CEC_DQEVENT:
+ return cec_dqevent(adap, fh, block, parg);
+
+ case CEC_G_MODE:
+ return cec_g_mode(adap, fh, parg);
+
+ case CEC_S_MODE:
+ return cec_s_mode(adap, fh, parg);
+
+ default:
+ return -ENOTTY;
+ }
+}
+
+static int cec_open(struct inode *inode, struct file *filp)
+{
+ struct cec_devnode *devnode =
+ container_of(inode->i_cdev, struct cec_devnode, cdev);
+ struct cec_adapter *adap = to_cec_adapter(devnode);
+ struct cec_fh *fh = kzalloc(sizeof(*fh), GFP_KERNEL);
+ /*
+ * Initial events that are automatically sent when the cec device is
+ * opened.
+ */
+ struct cec_event ev_state = {
+ .event = CEC_EVENT_STATE_CHANGE,
+ .flags = CEC_EVENT_FL_INITIAL_STATE,
+ };
+ int err;
+
+ if (!fh)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&fh->msgs);
+ INIT_LIST_HEAD(&fh->xfer_list);
+ mutex_init(&fh->lock);
+ init_waitqueue_head(&fh->wait);
+
+ fh->mode_initiator = CEC_MODE_INITIATOR;
+ fh->adap = adap;
+
+ err = cec_get_device(devnode);
+ if (err) {
+ kfree(fh);
+ return err;
+ }
+
+ filp->private_data = fh;
+
+ mutex_lock(&devnode->fhs_lock);
+ /* Queue up initial state events */
+ ev_state.state_change.phys_addr = adap->phys_addr;
+ ev_state.state_change.log_addr_mask = adap->log_addrs.log_addr_mask;
+ cec_queue_event_fh(fh, &ev_state, 0);
+
+ list_add(&fh->list, &devnode->fhs);
+ mutex_unlock(&devnode->fhs_lock);
+
+ return 0;
+}
+
+/* Override for the release function */
+static int cec_release(struct inode *inode, struct file *filp)
+{
+ struct cec_devnode *devnode = cec_devnode_data(filp);
+ struct cec_adapter *adap = to_cec_adapter(devnode);
+ struct cec_fh *fh = filp->private_data;
+
+ mutex_lock(&adap->lock);
+ if (adap->cec_initiator == fh)
+ adap->cec_initiator = NULL;
+ if (adap->cec_follower == fh) {
+ adap->cec_follower = NULL;
+ adap->passthrough = false;
+ }
+ if (fh->mode_follower == CEC_MODE_FOLLOWER)
+ adap->follower_cnt--;
+ if (fh->mode_follower == CEC_MODE_MONITOR_ALL)
+ cec_monitor_all_cnt_dec(adap);
+ mutex_unlock(&adap->lock);
+
+ mutex_lock(&devnode->fhs_lock);
+ list_del(&fh->list);
+ mutex_unlock(&devnode->fhs_lock);
+
+ /* Unhook pending transmits from this filehandle. */
+ mutex_lock(&adap->lock);
+ while (!list_empty(&fh->xfer_list)) {
+ struct cec_data *data =
+ list_first_entry(&fh->xfer_list, struct cec_data, xfer_list);
+
+ data->blocking = false;
+ data->fh = NULL;
+ list_del(&data->xfer_list);
+ }
+ mutex_unlock(&adap->lock);
+ while (!list_empty(&fh->msgs)) {
+ struct cec_msg_entry *entry =
+ list_first_entry(&fh->msgs, struct cec_msg_entry, list);
+
+ list_del(&entry->list);
+ kfree(entry);
+ }
+ kfree(fh);
+
+ cec_put_device(devnode);
+ filp->private_data = NULL;
+ return 0;
+}
+
+const struct file_operations cec_devnode_fops = {
+ .owner = THIS_MODULE,
+ .open = cec_open,
+ .unlocked_ioctl = cec_ioctl,
+ .release = cec_release,
+ .poll = cec_poll,
+ .llseek = no_llseek,
+};
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