Commit ca684386 authored by Hans Verkuil's avatar Hans Verkuil Committed by Mauro Carvalho Chehab

[media] cec: add HDMI CEC framework (api)

The added HDMI CEC framework provides a generic kernel interface for
HDMI CEC devices.

Note that the CEC framework is added to staging/media and that the
cec.h and cec-funcs.h headers are not exported yet. While the kABI
is mature, I would prefer to allow the uABI some more time before
it is mainlined in case it needs more tweaks.

This adds the cec-api.c source that deals with the public CEC API
and the Kconfig/Makefile plumbing.

The MAINTAINERS file is also updated.
Signed-off-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
[k.debski@samsung.com: code cleanup and fixes]
Signed-off-by: default avatarKamil Debski <kamil@wypas.org>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent 9881fe0c
......@@ -2847,6 +2847,22 @@ F: drivers/net/ieee802154/cc2520.c
F: include/linux/spi/cc2520.h
F: Documentation/devicetree/bindings/net/ieee802154/cc2520.txt
CEC DRIVER
M: Hans Verkuil <hans.verkuil@cisco.com>
L: linux-media@vger.kernel.org
T: git git://linuxtv.org/media_tree.git
W: http://linuxtv.org
S: Supported
F: Documentation/cec.txt
F: Documentation/DocBook/media/v4l/cec*
F: drivers/staging/media/cec/
F: drivers/media/cec-edid.c
F: drivers/media/rc/keymaps/rc-cec.c
F: include/media/cec.h
F: include/media/cec-edid.h
F: include/linux/cec.h
F: include/linux/cec-funcs.h
CELL BROADBAND ENGINE ARCHITECTURE
M: Arnd Bergmann <arnd@arndb.de>
L: linuxppc-dev@lists.ozlabs.org
......
......@@ -21,6 +21,8 @@ if STAGING_MEDIA
# Please keep them in alphabetic order
source "drivers/staging/media/bcm2048/Kconfig"
source "drivers/staging/media/cec/Kconfig"
source "drivers/staging/media/cxd2099/Kconfig"
source "drivers/staging/media/davinci_vpfe/Kconfig"
......
obj-$(CONFIG_I2C_BCM2048) += bcm2048/
obj-$(CONFIG_MEDIA_CEC) += cec/
obj-$(CONFIG_DVB_CXD2099) += cxd2099/
obj-$(CONFIG_LIRC_STAGING) += lirc/
obj-$(CONFIG_VIDEO_DM365_VPFE) += davinci_vpfe/
......
config MEDIA_CEC
tristate "CEC API (EXPERIMENTAL)"
select MEDIA_CEC_EDID
---help---
Enable the CEC API.
To compile this driver as a module, choose M here: the
module will be called cec.
config MEDIA_CEC_DEBUG
bool "CEC debugfs interface (EXPERIMENTAL)"
depends on MEDIA_CEC && DEBUG_FS
---help---
Turns on the DebugFS interface for CEC devices.
cec-objs := cec-core.o cec-adap.o cec-api.o
obj-$(CONFIG_MEDIA_CEC) += cec.o
/*
* 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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