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OpenCloudOS-Kernel/drivers/media/cec/cec-api.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* cec-api.c - HDMI Consumer Electronics Control framework - API
*
* Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
*/
#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 <media/cec-pin.h>
#include "cec-priv.h"
#include "cec-pin-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 __poll_t cec_poll(struct file *filp,
struct poll_table_struct *poll)
{
struct cec_fh *fh = filp->private_data;
struct cec_adapter *adap = fh->adap;
__poll_t res = 0;
poll_wait(filp, &fh->wait, poll);
if (!cec_is_registered(adap))
return EPOLLERR | EPOLLHUP;
mutex_lock(&adap->lock);
if (adap->is_configured &&
adap->transmit_queue_sz < CEC_MAX_MSG_TX_QUEUE_SZ)
res |= EPOLLOUT | EPOLLWRNORM;
if (fh->queued_msgs)
res |= EPOLLIN | EPOLLRDNORM;
if (fh->total_queued_events)
res |= EPOLLPRI;
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 = {};
strscpy(caps.driver, adap->devnode.dev.parent->driver->name,
sizeof(caps.driver));
strscpy(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 int cec_validate_phys_addr(u16 phys_addr)
{
int i;
if (phys_addr == CEC_PHYS_ADDR_INVALID)
return 0;
for (i = 0; i < 16; i += 4)
if (phys_addr & (0xf << i))
break;
if (i == 16)
return 0;
for (i += 4; i < 16; i += 4)
if ((phys_addr & (0xf << i)) == 0)
return -EINVAL;
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_validate_phys_addr(phys_addr);
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);
/*
* We use memcpy here instead of assignment since there is a
* hole at the end of struct cec_log_addrs that an assignment
* might ignore. So when we do copy_to_user() we could leak
* one byte of memory.
*/
memcpy(&log_addrs, &adap->log_addrs, sizeof(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 &= CEC_LOG_ADDRS_FL_ALLOW_UNREG_FALLBACK |
CEC_LOG_ADDRS_FL_ALLOW_RC_PASSTHRU |
CEC_LOG_ADDRS_FL_CDC_ONLY;
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->log_addrs.num_log_addrs == 0)
err = -EPERM;
else if (adap->is_configuring)
err = -ENONET;
else if (cec_is_busy(adap, fh))
err = -EBUSY;
else
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)
{
u32 timeout = msg->timeout;
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);
/* restore original timeout value */
msg->timeout = timeout;
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;
if (copy_from_user(&msg, parg, sizeof(msg)))
return -EFAULT;
err = cec_receive_msg(fh, &msg, block);
if (err)
return err;
msg.flags = 0;
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_entry *ev = NULL;
u64 ts = ~0ULL;
unsigned int i;
unsigned int ev_idx;
long err = 0;
mutex_lock(&fh->lock);
while (!fh->total_queued_events && block) {
mutex_unlock(&fh->lock);
err = wait_event_interruptible(fh->wait,
fh->total_queued_events);
if (err)
return err;
mutex_lock(&fh->lock);
}
/* Find the oldest event */
for (i = 0; i < CEC_NUM_EVENTS; i++) {
struct cec_event_entry *entry =
list_first_entry_or_null(&fh->events[i],
struct cec_event_entry, list);
if (entry && entry->ev.ts <= ts) {
ev = entry;
ev_idx = i;
ts = ev->ev.ts;
}
}
if (!ev) {
err = -EAGAIN;
goto unlock;
}
list_del(&ev->list);
if (copy_to_user(parg, &ev->ev, sizeof(ev->ev)))
err = -EFAULT;
if (ev_idx >= CEC_NUM_CORE_EVENTS)
kfree(ev);
fh->queued_events[ev_idx]--;
fh->total_queued_events--;
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;
bool send_pin_event = false;
long err = 0;
if (copy_from_user(&mode, parg, sizeof(mode)))
return -EFAULT;
if (mode & ~(CEC_MODE_INITIATOR_MSK | CEC_MODE_FOLLOWER_MSK)) {
dprintk(1, "%s: invalid mode bits set\n", __func__);
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) {
dprintk(1, "%s: unknown mode\n", __func__);
return -EINVAL;
}
if (mode_follower == CEC_MODE_MONITOR_ALL &&
!(adap->capabilities & CEC_CAP_MONITOR_ALL)) {
dprintk(1, "%s: MONITOR_ALL not supported\n", __func__);
return -EINVAL;
}
if (mode_follower == CEC_MODE_MONITOR_PIN &&
!(adap->capabilities & CEC_CAP_MONITOR_PIN)) {
dprintk(1, "%s: MONITOR_PIN not supported\n", __func__);
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) {
dprintk(1, "%s: cannot transmit\n", __func__);
return -EINVAL;
}
/* Monitor modes require CEC_MODE_NO_INITIATOR */
if (mode_initiator && mode_follower >= CEC_MODE_MONITOR_PIN) {
dprintk(1, "%s: monitor modes require NO_INITIATOR\n",
__func__);
return -EINVAL;
}
/* Monitor modes require CAP_NET_ADMIN */
if (mode_follower >= CEC_MODE_MONITOR_PIN && !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) {
bool old_mon_pin = fh->mode_follower == CEC_MODE_MONITOR_PIN;
bool new_mon_pin = mode_follower == CEC_MODE_MONITOR_PIN;
if (old_mon_pin != new_mon_pin) {
send_pin_event = new_mon_pin;
if (new_mon_pin)
err = cec_monitor_pin_cnt_inc(adap);
else
cec_monitor_pin_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 (send_pin_event) {
struct cec_event ev = {
.flags = CEC_EVENT_FL_INITIAL_STATE,
};
ev.event = adap->cec_pin_is_high ? CEC_EVENT_PIN_CEC_HIGH :
CEC_EVENT_PIN_CEC_LOW;
cec_queue_event_fh(fh, &ev, 0);
}
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_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 (!cec_is_registered(adap))
return -ENODEV;
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 = {
.event = CEC_EVENT_STATE_CHANGE,
.flags = CEC_EVENT_FL_INITIAL_STATE,
};
unsigned int i;
int err;
if (!fh)
return -ENOMEM;
INIT_LIST_HEAD(&fh->msgs);
INIT_LIST_HEAD(&fh->xfer_list);
for (i = 0; i < CEC_NUM_EVENTS; i++)
INIT_LIST_HEAD(&fh->events[i]);
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;
}
mutex_lock(&devnode->lock);
if (list_empty(&devnode->fhs) &&
!adap->needs_hpd &&
adap->phys_addr == CEC_PHYS_ADDR_INVALID) {
err = adap->ops->adap_enable(adap, true);
if (err) {
mutex_unlock(&devnode->lock);
kfree(fh);
return err;
}
}
filp->private_data = fh;
/* Queue up initial state events */
ev.state_change.phys_addr = adap->phys_addr;
ev.state_change.log_addr_mask = adap->log_addrs.log_addr_mask;
cec_queue_event_fh(fh, &ev, 0);
#ifdef CONFIG_CEC_PIN
if (adap->pin && adap->pin->ops->read_hpd) {
err = adap->pin->ops->read_hpd(adap);
if (err >= 0) {
ev.event = err ? CEC_EVENT_PIN_HPD_HIGH :
CEC_EVENT_PIN_HPD_LOW;
cec_queue_event_fh(fh, &ev, 0);
}
}
if (adap->pin && adap->pin->ops->read_5v) {
err = adap->pin->ops->read_5v(adap);
if (err >= 0) {
ev.event = err ? CEC_EVENT_PIN_5V_HIGH :
CEC_EVENT_PIN_5V_LOW;
cec_queue_event_fh(fh, &ev, 0);
}
}
#endif
list_add(&fh->list, &devnode->fhs);
mutex_unlock(&devnode->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;
unsigned int i;
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_PIN)
cec_monitor_pin_cnt_dec(adap);
if (fh->mode_follower == CEC_MODE_MONITOR_ALL)
cec_monitor_all_cnt_dec(adap);
mutex_unlock(&adap->lock);
mutex_lock(&devnode->lock);
list_del(&fh->list);
if (cec_is_registered(adap) && list_empty(&devnode->fhs) &&
!adap->needs_hpd && adap->phys_addr == CEC_PHYS_ADDR_INVALID) {
WARN_ON(adap->ops->adap_enable(adap, false));
}
mutex_unlock(&devnode->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);
}
for (i = CEC_NUM_CORE_EVENTS; i < CEC_NUM_EVENTS; i++) {
while (!list_empty(&fh->events[i])) {
struct cec_event_entry *entry =
list_first_entry(&fh->events[i],
struct cec_event_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,
.compat_ioctl = cec_ioctl,
.release = cec_release,
.poll = cec_poll,
.llseek = no_llseek,
};
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